WO2013102894A1

WO2013102894A1 - System and method for management of electric power consumption

Info

Publication number: WO2013102894A1
Application number: PCT/IL2012/050537
Authority: WO
Inventors: Liran Katzir
Original assignee: Better Place GmbH; Better Place Labs Israel Ltd.
Priority date: 2012-01-04
Filing date: 2012-12-20
Publication date: 2013-07-11
Also published as: TW201340026A; WO2013102894A8

Abstract

A system and method are provided for use in electric charging of batteries by an electric network while managing and/or optimizing a load balance state of the network. The method includes monitoring the electric network to determine a value of at least one load balance parameter in the electric network. Data indicative of one or more charging criteria is provided associating values of the load balance parameter(s) with various charging schemes corresponding thereto. The one or more criteria and the determined value of the load balance parameter(s) are used to select a charging scheme for charging a battery in consideration with the load balance state of the network.

Description

SYSTEM AND METHOD FOR MANAGEMENT OF ELECTRIC

POWER CONSUMPTION

FIELD OF THE INVENTION

This invention relates to management of electric power consumption from an electricity network, and more specifically relates to managing the operation of electric vehicle supply systems for charging electric vehicles. BACKGROUND OF THE INVENTION

Electric power utilities generally have a regulatory obligation to control frequency of electricity within tight limits. For example, the UK national grid is required to control the frequency as specified in the 'Electricity Supply Regulations' (The Electricity Supply Regulations 1988, No. 1057, PART VI, Regulation 30, Section 2) within a range of about +1% of nominal system frequency (50.00Hz). Therefore, Utilities typically ensure that sufficient generation and / or demand of electricity is controlled, so as to manage all credible circumstances that might result in frequency variations.

As electricity is difficult to store, the instantaneous generation of electricity typically matches the demand (i.e., the electricity being taken from the system). If the instantaneous demand is higher than the generation, the system frequency may fall. Conversely, if the instantaneous generation is higher than the demand, the frequency may rise. System frequency will therefore vary around the base frequency - the 50 or 60 Hz.

There are several types of load-balancing techniques currently used to manage and control the load on an electrical network/grid. These techniques may be schematically classified as power generation management techniques and demand management techniques. Generation management is a continuous service provided to manage and control a balanced state of the electric power distribution grid/network. The power utility or the regional operator follows the load (demand). When the demand increases the operator adds more generation power, and when demand is reduced also the generation power is diminished. Generation management is typically obtained by utilizing an operating reserve having the capacity to generate additional electric power for a short interval of time. The operating reserve may be used to meet demand, in cases where a generator stops operating, and if a disruption to the electric power supply is present. The operating reserve typically includes several types of power generation services that are capable of responding to changes in the load balance state of the grid in times scales of between several seconds and tens of minutes. For example an operating reserve may include a spinning reserve, a non-spinning or supplemental reserve, a regulating reserve and a replacement reserve (also known as contingency reserve).

Demand management techniques allow control over the rate for power consumption from the electric power distribution grid. Demand management techniques may be used to level the load on the grid by shifting the demand for power consumption from peak times to earlier or later times. This is achieved for example by utilizing price signaling to discourage high demand for power at peak hours. Discrete-demand management techniques utilizes an ability to automatically disconnect users in cases of substantially unbalanced load on the grid (e.g. if an emergency occur). Discrete-load- balancing techniques are typically associated with a very fast response times of less than seconds (e.g. 200 milliseconds). In most of the world big power consumers (e.g. big factories consuming over 3-5 Mega Volt- Amperes) are offered discount on electricity if they agree to install discrete-load-balancing devices in their main power feed. GENERAL DESCRIPTION OF THE INVENTION

Growing use of electric and hybrid vehicles (referred to herein as EV's) presents challenges to the operation of electric power distribution grids/networks. EV batteries typically need to be charged for several hours to reach their full power capacity. Since multiple vehicles are typically used during traffic rush hours, substantial load on the electricity network is expected to follow the traffic rush hours when those vehicles are plugged for charging. The present invention addresses this problem and provides a novel technique (system and method) for demand management of electric power consumption from the grid. The technique of the present invention is suitable for use by multiple power consuming utilities such as multiple EVs, electric vehicle supply equipment (EVSE) used for charging batteries, and other power consuming equipment connectable to the grid.

The present invention may be implemented as a standalone independent utility operating in association with an individual power consuming utility to allow connecting such power consuming utility to the grid while not causing the gird to reach an overloaded state in case multiple such utilities are connected to the grid at substantially the same times. To this end, the utility of the present invention may operate, in real time, independently from other utilities thus providing agile real time response to changes in the grid state. Also, the present invention may be used to control and adjust the electric power services consumed by such utilities in order to provide good service- level to those utilities. The service level provided to the power consuming utilities may be controlled and adjusted by prioritizing the power supply to selected utilities.

Specifically, a system according to the invention may be configured and operable for providing power replenishment services to batteries, while allowing demand management of the power consumption from the grid. Systems and methods of the invention may be used for example in association with charging modules and/or EVSEs to manage their electric power consumption. Such systems may be used to charge batteries of electric and/or hybrid vehicles (commonly referred to herein as EVs) while optimizing the operation of the electric grid.

Power replenishment of multiple EVs (EVs' batteries) may be prioritized and distributed over time in order to level the load on the grid. This has particular significance during peak power consumption hours. The distribution of the load over time enables the operator of the power distribution grid to follow the load and meet the power demand at a response time scale available to him. When needed, the grid's operator may operate to increase generation of power to the network (operation which may take between few minutes to one hour) while in the mean time network stability and balanced load state is maintained, at least partially, through demand management/regulation provided by the technique of the present invention. The invention thus provides a system and a method providing real time response to the load balance state of an electric network. The response is provided, distributed in the network, by independently controlling the operation of one or more power consuming utilities and adapting their electric power consumption in accordance with predetermined criteria. Namely, each power consuming utility makes real-time independent decision as regarding the amount of power to be consumed-from (possibly also provided to) the grid based on predetermined conditions/criteria provided thereto in advance.

To this end, it should be noted that the present invention allows provision of real-time power demand management with short response times which may be below few seconds and optionally less than 1 second (e.g. in the order of few milliseconds to 500 milliseconds). The short response time is attained by the fact that monitoring of the gird's frequency and adapting power consumption may performed locally and in realtime (e.g. by an EVSE system) without a need to communicate with external utilities such as central control system managing power replenishment for EV or batteries thereof. Thus, the invention allows deployment of multiple EVSE's (e.g. charging stations/spots, portable-charging-utilities) which are adapted (according to predetermined instructions) to respond in real-time to variations in the electric grid operation while maintaining overall prioritization for charging electric vehicles. Also, EVSE's configured according to the invention may be adapted to operate independently from one another (e.g. as a standalone units) and may possibly not require real-time use of data communication.

Distributing the power consumption of the multiple EV-power replenishment utilities (e.g. of multiple EVSEs ) over time is achieved by monitoring the load-balance state of the electrical network and controlling the instantaneous power consumption of the EVSEs. An EVSE system typically has the ability to sense the frequency of the grid. The technique of the invention may utilize the sensed frequency to determine the grid's load balance state and accordingly manage the power consumption of the EVSE. This, in turn, allows control over the grids frequency by relieving excess demand from the grid (e.g. by selectively and automatically turning-off and on battery/EV charging).

As noted above, the operation of the EVSE's may be prioritized to provide different power replenishment services to different EV's connected thereto. A standard dealing with communication between the EVSE and the Electric vehicle (EV) is developed in a joint work group between IEC TC 69 and ISO TC 22/SC 21. This standard deals inter-alia with the exchange of data between a battery management system (BMS) on board the EV and an EVSE used to replenish the power of the EV's battery. Specifically, data indicative of the state of charge (SOC) of the battery may be obtained by the EVSE. The SOC data may be used according to the invention to prioritize power replenishment services provided to the EV. It should be noted that SOC is only an example of a possible prioritizing parameter. Other examples of prioritizing parameters are also described below. The power consumption of a power- consuming-utility/EVSE may be adjusted by controlling the operation of the utility, for example by selectively disconnecting/connecting the utility from the grid or selectively turning it on and off in accordance with the grid state and the prioritizing data.

For example, when an over-loaded grid state is identified (e.g. when the frequency of the grid drops), an EVSE utility of the invention may operate in accordance with the SOC of the EV for turning off charging and/or to change the power consumption used for charging the battery. EVs with a higher SOC will disconnect from charging at higher grid frequencies and only after that, at lower frequencies and if needed, EVs with lower SOC will disconnect from charging. Reconnection of power for charging the EV's may be performed in a reverse order: EVs with a lower SOC will be connected first and only later will be followed by EVs with high SOC.

Conditions/criteria for the modes/schemes of operation of the power consuming utilities at different grid conditions (different load balance states) may be selected in accordance with requirements from the electric- networks operator/aggregator and also in accordance with certain prioritizing parameters. For example the criteria for operating power consuming utilities may be defined per sub-groups of the power consuming utilities (e.g. per sub section of utilities which are serviced/powered by a certain service provider). Additionally or alternatively, the criteria may in some cases be defined globally (e.g. by a control center of the service provider and/or by the operator of the electric network) and/or in some cases the criteria may be also be defined locally by an electric network aggregator, such as a parking lot controller, providing power replenishment services to multiple EV's.

The relationship between the operation scheme of the power consuming utilities (i.e. referred to herein as charging schemes), the load balanced state of the grid, and possibly additional parameters such as prioritizing parameters may be defined in a criteria (also referred to herein below as charging criteria) represented in lookup table (LUT) or by one or more functions or algorithms. The criteria may associate different load balance states of the grids with various operation schemes which may include schemes associated with various power consumption rates and possibly also schemes providing/inputting power to the grid.

The charging criteria may be a fixed function/table or it may be dynamic criteria which might be updated every once in a while. The criteria may be defined statically in a system controlling the power consumption of such power consuming utility and/or it may be updated from time to time possibly through data network communication. Typically, updates to the criteria are made such as to not delay the real time response of the system. For examples such updates may be performed in the background of the system's operation in a manner not affecting the system's real time response to changes in the grid state.

For example, the charging criteria may be calculated locally on power consuming utility/EVSE, by an electric power supplier/aggregator (e.g. a parking lot aggregator) and/or on the provider's control center. Such criteria may also be calculated and updated based on properties of multiple power consuming utilities (for example based on the SOC of multiple/all vehicles associated with a certain fleet) associated with a vehicle network of a certain energy replenishment provider. The calculated criteria may for example defines a specific SOC point(s) and electric grid frequencies at which EVSE's would operate to connect/disconnect batteries for charging. The calculated charging criteria may also, for example, define a LUT sorted according to SOC and service level (SL) parameters.

To this end, SL parameters are considered herein as parameters associated with service levels to be provided to various users (e.g. in accordance with the types of service level agreements (SLA) made with those users). SL parameters may be used to prioritize the receipt of certain power replenishment services by some users over other users.

According to the invention, the criteria (charging criteria) may implement hysteresis operation modes for preventing oscillations in the demand for electric supply. To this end, hysteresis may be implemented by setting the criteria for disconnecting or lowering the power consumption rates of power consuming utilities grid loads (higher overloaded states) to be lower than the load/load balance criteria for reconnection or restoration of the power consumption rates of the utilities. For example, in an hysteresis operation, an EV with specific SOC is cut off from charging when the frequency of the grid goes below X, and is reconnected again only when frequency goes above X+ Positive Delta.

As noted above prioritizing parameters (e.g. the SOC of the battery), and possibly also other parameters such as battery parameters/characteristics, may be used in determination of the operation/power consumption of the power consuming utility (EVSE/battery charger etc'). Such parameters may be provided directly from the EV via the charging cable and/or wirelessly, and/or they may be communicated by the EV on board computer to the control center and from there to the specific EVSE. As will be also described below, the charging criteria/function may take into account additional information/parameters, such as the type of service guaranteed to the specific EV, the typical or current destination of its trip, and the required charging level to reach the destination. The system of the invention may also use process such additional information to estimate various parameters. For example an approximation of the battery SOC may be determined according to the charging time duration and the current supplied by the EVSE in addition to periodic information from the control center.

Thus according to one broad aspect of the present invention there is provided a method for use in electric charging of batteries by an electric network. The method includes: providing data indicative of one or more charging criteria associating one or more values of at least a load balance parameter of the electric network with charging schemes corresponding to the one or more values; monitoring the electric network to determine a value of the load balance parameter in the network; and utilizing the one or more criteria and the determined value to select a charging scheme to be used for charging a battery.

According to some embodiments of the invention at least one of the charging criteria is additionally associating one or more prioritizing parameters, corresponding to prioritized charging of a battery, with a corresponding charging schemes. In such embodiments the method also includes obtaining prioritizing values corresponding to the one or more prioritizing parameters in a battery to be charged, and selecting the charging scheme in accordance with the prioritizing values and the determined value of the load balance parameter. The prioritizing parameters may include a state of charge (SOC) parameter indicative of the SOC of said battery to be charged. The value of the SOC parameter may be determined based on battery data received from onboard an electric vehicle at which the battery is installed. For example the value of the SOC parameter may be estimated based on battery-usage data indicative of at least one of the following: a previous SOC of the battery, battery service history data, and expected usage of the battery or a vehicle upon which said battery is installed.

The prioritizing parameters may alternatively or additionally include at least one of the following parameters: a service level (SL) parameter indicative of the service level to be provided to a vehicle upon which said battery is installed, and an expected usage (EU) parameter indicative of the expected power consumption to be used for driving said vehicle. The values of the SL and EU parameters or one of them may optionally be at least partially determined based on data received from onboard the vehicle.

According to some embodiments, the method of the present invention also includes obtaining information indicative of an identity of the battery to be charged and communicating that information to a control center for receiving therefrom at least one of the prioritizing values corresponding to the battery and/or one or more of the charging criteria to be used with the battery.

According to some embodiments of the invention the charging criteria are selected to optimize load balancing in the electric network. For example the charging criteria may associate over-load and under-load values of the load balance parameter, which correspond to over-load and under-load states of said electrical network, with the charging schemes having lower and higher power consumptions respectively thereby optimizing load balancing in the electric network. Alternatively or additionally, for a given set of the prioritizing values, the charging criteria associate over-load and underload values of said load balance parameter with charging schemes having lower and higher power consumptions respectively. This thereby provides for optimizing load balancing in the electric network while also providing prioritized service to users of the batteries and all-to-all improvement of the provided service level.

It should be noted that according to some embodiments of the invention the load balance parameter corresponds to a frequency of electricity in the electric network. To this end, according to some embodiments the method of the invention includes monitoring the frequency of said electric network to thereby determine a load balance state of the electric network. A frequency of the electric network being higher than a certain nominal frequency value of the network indicating the network operation in an under- load state, and the frequency of the electric network being lower than the nominal frequency indicating an over load state of the network.

According to some embodiments of the invention, at least one of the charging schemes may be indicative of a sequence of one or more charging cycles each including at least a charging period during which the battery is being charged and a recess period during which the battery is not charged. The one or more charging cycles may be, for example, periodic cycles with equal periods.

According to another broad aspect of the present invention there is provided a system for use in charging batteries by an electric network. The system includes a Charging-Protocol module configured and operable for providing data indicative of one or more charging criteria associating one or more values of at least a load balance parameter indicative of a load balance in the electric network with corresponding charging schemes. The system also includes an Electric Network Monitoring module associated with an electric network and adapted for providing data indicative of a value of said load balance parameter in the network. Additionally the system includes a Charging controller configured and operable for communication with the charging- protocol module and the electric network monitoring module. The Charging controller is adapted for utilizing the one or more charging criteria and the data indicative of the value of the load balance parameter to select a charging scheme for use in operating a Battery Charging module.

According to some embodiments of the present invention the system also includes a Battery Charging module that is connectable to the Charging controller and adapted for receiving therefrom a signal indicative of the selected charging scheme. The Battery Charging module may be operable for charging an electric vehicle in accordance with the selected charging scheme.

According to some embodiments of the present invention the system also includes a Prioritizing module that is adapted for providing prioritizing values corresponding to one or more prioritizing parameters associated with priority charging of batteries. In such embodiments, at least one of the charging criteria associates one or more values of the prioritizing parameters with a corresponding charging scheme. To this end, the Charging-Protocol module may be adapted for receiving, from the Prioritizing module, one or more prioritizing values corresponding to a specific battery to be charged and for providing corresponding charging criteria data. Alternatively or additionally, the Charging controller may be adapted for receiving, from the Prioritizing module, one or more prioritizing values corresponding to a specific battery and utilizing prioritizing values in determination of the selected charging scheme.

The prioritizing parameters may include a state of charge (SOC) parameter indicative of the SOC of a battery to be charged. The Prioritizing module may be configured and operable for communicating with a control system on board the vehicle for receiving therefrom battery data indicative of a SOC of the battery. Alternatively or additionally, the Prioritizing module may be configured for estimating said SOC parameter based on at least one of the following: battery-usage data indicative of at least one of a previous battery SOC, battery service history data, and expected usage of a battery or a vehicle upon which said battery is installed.

According to some embodiments of the invention, the prioritizing parameters include at least one of the following: a service level (SL) parameter indicative of the service level to be provided to a vehicle upon which said battery is installed, and an expected usage (EU) parameter indicative of the expected power consumption from the battery. For example the Prioritizing module may be configured and operable for communicating with a control system on board said vehicle and receiving therefrom data indicative of a value of at least one of the SL and EU parameters.

According to some embodiments of the invention the system may include an identification module adapted for obtaining information indicative of an identity of the battery and communicating the information to a control center. The identity information may be indicative of the identity of at least one of the following: said battery, a vehicle upon which said battery is installed, and a user of said vehicle. In response to the communication of identity information, the Prioritizing module may be adapted for receiving, from the control center, values corresponding to one or more of the prioritizing parameters. Alternatively or additionally, the Charging-Protocol module may be adapted for receiving at least one of the charging criteria corresponding to the identity information.

According to some embodiments of the invention, the Charging-Protocol module is operable for providing charging criteria adapted for optimizing load balancing in the electric network. The charging criteria may associate over-load and under-load values of said load balance parameter, which correspond to over-load and under-load states of said electrical network, with charging schemes having lower and higher power consumptions respectively. Alternatively or additionally, for a given set of prioritizing values, charging criteria associating over-load and under-load values of said load balance parameter with charging schemes having lower and higher power consumptions respectively. This thereby provides for improving load balancing in the electric network while also optimizing the power replenishment services provided to users of the system.

According to some embodiments of the invention, the system includes a

Frequency Monitoring module connectable to said electric network and adapted for measuring the load balancing parameter indicative of at least a frequency of electricity in the network. The frequency value corresponds to a load balance state of the network. According to some embodiments of the invention the Charging-Protocol module may be adapted for providing data indicative at least one charging scheme comprising a sequence of charging cycles each including at least a charging period and a recess period. The Charging-Protocol module may be adapted for providing charging schemes having different ratios between durations of the charging periods and durations of the charging cycles thereby providing charging schemes associated with different power consumption rates. The Charging controller may be adapted for utilizing the charging criteria for selecting and utilizing such charging schemes and to charge the battery during charging periods while not charging the battery during recess periods.

According to yet another broad aspect of the present invention there is provided a system for use in charging batteries by an electric network. The system includes a Charging-Protocol module providing data indicative of one or more charging criteria associating one or more values of at least a load balance parameter indicative of a load balance in the electric network with corresponding charging schemes associated with different power consumption rates. The charging schemes include sequences of charging cycles including at least charging periods and recess periods having a different ratio between duration of the charging period and recess period, as compared to at least some other schemes. The system also includes an Electric Network Monitoring module and charging controller. The Electric Network Monitoring module is associated with an electric network and adapted for determining a value of the load balance parameter in the network. The Charging controller is adapted for utilizing the one or more charging criteria and the value of the load balance parameter to select a charging scheme to be used for operating a Battery Charging module to charge a battery in accordance with the selected charging scheme.

According to yet further broad aspect of the present invention there is provided a method for use in charging batteries by an electric network. The method includes: providing data indicative of one or more criteria associating values of frequency of electricity in the network with charging schemes and monitoring the electric network to determine an instantaneous value of the frequency of electricity in said network. Then, the one or more criteria are used to select a charging scheme to be used for charging a battery. The charging schemes may include charging cycles. At least some of the charging schemes may be associated with different power consumption rates corresponding to different ratios between a charging period duration of their charging cycle and the total and duration of their charging cycles.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Fig. 1 is a flow chart 100 illustrating a method use in charging battery(ies) from an electricity network.

Figs. 2A-2D show four examples of charging criteria, represented in LUTs, which may be used in charging batteries from the electricity.

Fig. 3 is a block diagram schematically illustrating a system for use in charging a battery(ies) according to the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Reference is made to Fig. 1 showing a flow chart 100 illustrating a method, according to an embodiment of the present invention, for use in charging battery(ies) from an electricity network. According to some embodiments of the invention method 100 may be partially or entirely implemented in an electric circuitry and/or by software modules embodied in a non-transitory computer readable storage medium that stores one or more programs for execution by one or more processors of a computerized system.

Method 100 includes: providing data indicative of one or more charging criteria associating one or more values of at least a load balance parameter of the electric network with charging schemes corresponding to the one or more values (110); providing a value of the load balance parameter in the network (120); and utilizing the one or more criteria and the value of the load balance parameter to select a charging scheme to be used for charging a battery (140).

Optionally, at least one of said charging criteria additionally associates one or more prioritizing parameters, corresponding to prioritized-charging of the battery, with corresponding charging schemes. In such embodiments, the method also includes the step of obtaining prioritizing values corresponding to the one or more prioritizing parameters in a battery to be charged (130). If the step 130 is also present, the selected charging scheme selected in step 140 is also in accordance with the prioritizing values obtained at 130.

The term electricit -network also referred to herein as grid, is the electric network from which electric power is provided for charging batteries. The method 100 may be implemented in association with a battery charging module to improve/optimize load balancing in the network, and optionally to further provide prioritized charging of batteries. The method of the present invention allows changing the load on the network, in order to relieve/avoid overloading the network. This method may be particularly useful in cases where multiple batteries are charged from the network at overlapping time periods. Furthermore, the present method may also allow provision of a desired service level (SL) to users of the batteries.

To this end, the terms load balancing and load balance state are used herein in association with the balance between the instantaneous amount of electric power supplied to the electricity- network/grid (e.g. by power plants) and the instantaneous load/power-demand from the grid. The term balanced load state indicates a state where the instantaneous generation of electric supply to the grid is substantially equal to the instantaneous demand of electricity. The terms over-loaded and under-loaded states are used herein to respectively describe states where the rate of power demand from the grid is higher than rate of power generated/supplied to the grid and vice- versa. As was noted above, the expected extensive use of electric-vehicles (EVs) presents significant challenges in provision of electric supply for charging the batteries of such vehicles. This is, inter-alia, because significant electric power is required for charging an EV's battery (e.g. as high as lOkWatts or even higher) and because the majority of electric vehicles are expected to be connected for charging at common schedules (charging-rush- hours), such as during the working hours of the day (e.g. between 09:00 and 17:00) and during the night time (e.g. between 20:00 and 06:00). As a result, in the absence of techniques for controlling and adjusting the vehicles' charging operations, the electric grid might be overloaded during certain charging-rush-hours (e.g. at time frames when many people arrive at their working places). An over-loaded state of the electricity network, at such charging-rush-hours, may cause significant instabilities in the electric supply and possibly damage electric equipment plugged to the network. The present invention solves these problems by presenting technique for charging electric batteries while facilitating the maintenance of a balanced load state in the electric grid. Load balancing systems of the present invention may operate independently of each other for allowing connection of multiple batteries for charging at the substantially the same time frames (e.g. simultaneously) without instigating an overloaded state of the electricity- network.

Thus, according to the method 100, one or more charging criteria CRT are provided in 110 associating values of a load balancing parameter of the network with several (two or more) charging schemes. The charging schemes are associated with various operational modes (charging parameters) of a battery charging module and at least some of the charging schemes are associated with different power consumption rates from the electric network. For example two such charging schemes may be associated with the battery charging being turned ON and OFF respectively.

In 120, the data indicative of the value(s) of one or more load balancing parameters in the electric network is provided. Optionally, according to some embodiments of the invention, electric parameters indicative of the load balancing state of the grid are monitored/measured (e.g. at the charging spot). Measuring electric parameters of the grid may be performed at fast rates for providing substantially realtime response to changes in the grid's state.

As noted above, the frequency of the electricity in the grid is typically an indicator to the load balancing state of the grid (as such it may serve as a load balance parameter). Conventional electric networks worldwide typically provided either 220V or 110V AC voltages alternating at nominal frequencies of either 50 or 60Hz (depending on the electric network and state at which it resides). However, the instantaneous frequency of electric supply through an electric grid/network is typically susceptible to the load balancing state of the network (i.e. to the balance between the power supply-to- and demand- from- the grid). In over- load situations, where instantaneous demand exceeds generation of electric power, the grid's frequency drops below its nominal frequency. In under-load situations, where the instantaneous demand for power is below the rate of electric power generation, the grid's frequency rises above the nominal frequency.

Thus, according to some embodiments of the invention, the load balance state of the grid is provided in 120 by measuring the instantaneous value of the electric frequency of the grid and possibly determining a deviation value between the measured frequency and the nominal electric frequency of the grid. In such embodiments the charging criteria CRT, provided in 110, may be adapted for associating values of the measured instantaneous frequency (or of deviation of the instantaneous grid's frequency from its nominal frequency) with various charging parameters/schemes, possibly having different power consumption rates. Certain charging schemes may in some cases also be associated with provision of power to the grid (e.g. by drawing power from the battery) to relieve overloaded grid states.

Alternatively or additionally, according to some embodiments of the present invention, data indicative of the network load balance state may also be communicated through a data network. For example, a load balancing parameter(s) of the network may be communicated from the utility company operating the electricity network or from a central control system controlling the operation of multiple charging systems (charging spots).

Optionally, according to some embodiments of the invention, not all batteries to be charged have the same charging priority. To this end, prioritizing data/parameters may be also incorporated in the charging criteria to allow prioritized charging of batteries. For example, in charging batteries of electric vehicles, some batteries/EVs/users may be associated with higher service level agreement (SLA) than others thus getting higher priority for charging their batteries. Also for some vehicles, the expected use of the vehicle may be lower than that of other vehicles and/or the state of charge (SOC) of their batteries may be higher than the SOC of other vehicles. In such a case, a lower charging priority may be set for the vehicles with lower expected use or vehicles with higher SOC.

In addition, a charging module of the present invention may optionally be configured for charging different types of batteries which may be associated with different charging characteristics (e.g. different rates of power consumption during charging). These battery charging characteristics, indicated herein by the term battery parameters, may also be incorporated in the charging criteria and used for selecting a proper charging scheme.

As mentioned above, in the optional step 130, prioritizing data and/or battery data is provided/obtained for charging a specific battery (e.g. of a specific EV/user). The prioritizing-data and battery-data, being respectively indicative of the values of the prioritizing- and battery- parameters of the specific battery to be charged, may be obtained from one or more controllers associated with the battery to be charged. Such controllers may include the following: the BMS (battery management system) of the battery (e.g. furnished with a device/EV carrying the battery), and a remote central control system (control-center) in communication the battery. Battery data pieces and prioritizing data pieces may be provided from a single controller of from several controllers associated with the specific battery. Also, such data may be obtained through data communication (e.g. via a data network). In some cases, specifically when the controller is associated with several batteries (e.g. central control system), the battery- and/or the prioritizing- data may be provided in response to communication of data indicative of the battery type/identity to the controller. Data indicative of the battery type/identity may be for example data identifying the EV upon which the battery is installed and/or data indicative of the user of the battery/EV.

Optionally, the prioritizing- and battery- data provided at 130 may be partially or entirely in the form of charging criteria CRT specifically designed in accordance with the priority, type and/or identity of the specific battery to be charged.

In 140, the charging criteria (provided in 110 and optionally in 130) are utilized to select a charging scheme based on the value of the load balance parameter(s) provided in 120, and possibly also based on the prioritizing- and/or battery- data provided in 130. The charging criteria may be in the form of a lookup table (LUT) or a formula or algorithm associating values of at least the load balance parameter(s) with corresponding charging schemes/parameters. Accordingly, in 140, an appropriate charging scheme selected.

In some embodiments of the invention, the selection of the charging scheme is performed in hysteresis mode to prevent oscillations in the power consumption of the charger and to improve network stability. In an hysteresis mode, the criterion of operating according to a certain charging scheme is different than the criterion for ceasing to operate by that scheme. For example a battery with specific SOC is cut off from charging when the grid's frequency falls below a first threshold X, and reconnects for charging only when the frequency rises above a second threshold higher than the first threshold (X + Positive Delta). Characteristics/parameters of the hysteresis operation mode may be provided together with the charging criteria above or they may be hard coded in the system of the invention.

It is noted that steps 120 and 140 are preferably carried out repeatedly and/or periodically in order to monitor changes in the load balance state of the electric network and to appropriately adjust the charging scheme used for charging the battery. As noted above, it is generally preferable to provide agile response to changes in the load balance state of the grid, with a load balance response time preferably below few seconds and more preferably less than 1 second. Accordingly, steps 120 and 140 may be repeated with fast rate (e.g. about every 500msec) to account for and respond to such changes. Steps 110 and 130 may be carried out once, or every once in a while, for providing/updating the charging criteria and/or when different batteries are connected to be charged by the system.

According to various embodiments of the invention, a charging scheme may be represented by one or more charging parameters indicating the manner by which a battery should be charged. In step 150, operational instruction (e.g. data and/or signals) for charging a battery are determined based on the charging parameters of the charging scheme selected in 140. The operational data and/or signals are then used for operating a charger module to charge a battery according to the selected scheme. For example, a charging scheme may be represented by a single parameter indicating charging and un- charging states (ON-OFF states) of the charging module.

According to some embodiments of the invention method 100 may be operated to maintain the grid in slightly off-balance load state. Operation of method 100 in this manner may be used in order to encourage changes in the electric power generation supplied to the grid. For example, during charging-rush-hours, when multiple EVs are connected for charging, it may desired to "signal" to the grid's operator/utility-company, to increase the electric supply to the grid (increase electric generation). As noted above, the grid's operator is typically monitoring the load on the grid and adjusts the electricity generation accordingly to maintain a load balanced state. Thus, maintaining the grid state slightly overloaded "signals" the operator to increase in the electricity generation and vice-versa. Operating method 100 to maintain the grid at slightly off-balance load states can be achieved by utilizing suitable charging criteria. For example slightly overloaded grid states may be obtained by use of charging criteria with associate power consuming charging schemes with such slightly overloaded grid states. Alternatively or additionally, any one of steps 140 and/or 150 described above may be used to bias the selection of the charging scheme and/or to bias the operational charging instructions in order to affect a slightly un-balanced grid states. Preferably, the operation of method 100 to maintain the grid in slightly off-balance load state, does not include "active" over-loading/under- loading of the grid but rather passively refraining from correcting an unbalanced state of the grid when the grid is operating near the optimal load balanced state.

According to some embodiments of the invention, a charging scheme may be represented by one or more parameters indicating the average/nominal rate of power/current consumption to be obtained during charging. This can be achieved for example by adjusting the operation of a charger module to not exceed the desired power/current consumption. However, in some cases, the time required for adjusting the operation of the charger may be greater that the desired load-balance state response time. In such cases, in 150, in situations of overloaded grid states, the operation of the charger module may be first shutdown/disconnected, then properties of the charge's operation may be adjusted to comply with the required level/rate power consumption and, only afterwards the charger may be turned on again.

Alternatively or additionally, a desired average power/current consumption of the charger module (or of other power consuming utility) may be achieved by operating the power consuming utility in cycles/pulses. For example, a certain charging scheme may be specified/represented by a single charging parameter indicating a certain average/nominal power consumption rate to be used for charging the battery; e.g. nominal power consumption of 2 kWatts. Considering a case where the power consumption allowed for continuous charging of that certain battery is about 10 kWatts, then in order to charge that battery with average power consumption of 2KW, the battery should be charged during only a fraction 2KW/10KW = 0.2 of the time. This can be obtained according to the invention by operation the charger module in charging cycles including charging time- slots/periods during which the battery is charged and recess time- slots/periods during which the battery is not charged. Thus, in such embodiments of the invention, in 150 operative data/signals are generated for charging the battery in charging cycles where a ratio between duration of the charging period of a charging cycle and the total duration of the cycle substantially equals to the above described ratio 0.2. This provides charging the battery with a nominal power consumption rate of 2 kWatts. Fluctuations in the power consumption of the charger module which may result from such pulsed operation may be averaged out by the operation of multiple un- synchronized chargers operated in this manner and/or such fluctuations might be smoothed out by suitable electric circuits (e.g. by utilizing capacitors). Accordingly, utilizing such technique, substantially constant and reduced rate of power consumption may be obtained for charging multiple batteries form the grid while optimizing load balancing and improving stability of the electrical network.

Reference is now made to Figs. 2A-2D which show schematically several specific and non-limiting examples of charging criteria exemplified in the form of LUTs. It should be understood that equivalent, or other, charging criteria may also be provided in the form of one or more formula and/or algorithms as noted above. It should also be noted that other schemes of charging criteria may be used in by various embodiments of the present invention with other parameters and/or with other combinations of the parameters which are described in relation to any one of Figs. 2A- 2D.

Figs. 2A and 2B illustrates charging criteria arranged in a lookup table LUT and relating different values/ranges of the grid's frequency Fq (being a measure of the load- balance state of the grid), with the charging parameters of various charging schemes. In Fig. 2A the charging schemes are specified in this example by a single charging parameter being either one of a Boolean charging operation parameter indicating ON and OFF states of the charging (connecting/disconnecting charging current supply) or a charging power parameter CCp ([kWatts]) indicating the desired charging power consumption rate to be obtained by the corresponding charging scheme. In Fig. 2B the various charging schemes are specified by a Charging Cycle ratio parameter CC_R ([%]) indicating a fraction of the actual charging time (pulse duration) to the entire duration of the charging cycle. Optionally additional parameter CC_F ([HZ]) indicative of the repetition rate/frequency of the charging cycles/pulses is also provided (this is the inverse of a pulse duration).

According to the invention, in order to contribute to a balanced load state of the grid and in the absence of additional parameters (such as prioritizing and/or battery parameters described above), the charging criteria is selected such that there is a positive correlation between the value of the load balance state of the grid (grid's frequency Fq parameter) and the power consumption rate of the charging scheme. To this end, in connection with the charging criteria of Figs. 2A and 2B, a positive correlation should be provided between the grid's frequency Fq parameter and at least one of the charging power consumption rate parameter CCp and Charging Cycle ratio parameter CC_R. Accordingly, for under-loaded grid states, for which the grid's frequency is relatively high, charging schemes with higher power consumption (e.g. and shorter overall charging time) would be used and vice-versa for over-loaded grid states.

Fig. 2C illustrates another example of a charging criterion according to the present invention, associating various charging schemes with parameters indicative of the load balancing state of the grid and with additional parameters including prioritizing-parameters and battery parameters. Here, for example, a load-balance indicator/parameter LB is provided in percentage, in terms of the excess load on the grid relative to the power load for a balanced grid state. Optionally, the value of this parameter in the grid may be communicated from an external utility, such as a central control system, rather than being directly measured from the grid. Additionally, in this example, charging schemes are represented by a single charging operation parameter CO being a Boolean parameter indicating ON and OFF states of the charger module.

The charging criteria illustrated in Fig. 2C includes also prioritizing parameters and battery parameters allowing prioritized charging of certain specific batteries based on properties of the Battery and/or charger associated therewith and also based on a certain desired service level to be provided to the battery or to its associated user/vehicle. To accomplish provision of a desired service level, certain parameters indicative of the expected use of the battery (or EV associated therewith), the state of the battery/EV may also be considered. It should be noted here that the term prioritizing parameters is referred to herein broadly in association with various properties/parameters indicative of the priority for charging the battery and used in order to affect the selection of the charging scheme. To this end, the prioritizing parameters may include any combination of one or more of the following parameters and possibly also additional parameters:

(i) SOC - state of charge (SOC) of the battery. May be indicated by the amount of energy stored in the battery and/or fraction of the stored energy relative to the fully charged battery state.

(ii) EU - expected usage (EU) of the battery (e.g. in kWattsHour) which is due within a certain time frame. This may also be indicated by the expected use of a device/EV connected to the battery (e.g. driving expectancy in kilometers).

(iii) SL - service-level parameter may be a number indicating the service-level agreement (SLA) associated with charging the battery.

It should also be noted that the term battery-parameters is used herein to indicate any one or more parameters which are indicative of the battery charging characteristics (such as current/power consumption during charging). Such parameters may be associated with the type of the battery itself, and/or charger associated with the battery and/or with any other element(s)/factor(s) which might affect the battery charging operation. Battery-parameters may also be used in the present example for the determination of a suitable charging scheme to be used with specific battery type/identity. A specific non-limiting example of such parameters may in include the following or any combination thereof:

(i) BT - battery installed on the EV, its type or other properties thereof (not present in the figure).

(ii) CG - type of battery controller/charger (e.g. BMS) used for charging the battery (not present in the figure).

(iii) I -current drawn when charging the battery.

(iv) BC - power- storing capacity of the battery.

As noted above, the charging criteria are typically designed to optimize load balancing in the electric grid while preferably also provide improved power replenishment service levels. This may be obtained according to the by designing the charging criteria such that for equal sets of values of the prioritizing- and battery- parameters, there is a negative correlation between the load-balance state of the grid and the power consumption rate of the corresponding charging schemes provided by the systems for such states. For example for the same prioritizing, higher power consuming schemes would be provided for slower grid frequencies. On the other hand, in order to improve the service level of power replenishment services, the charging criteria may also be designed such that for similar load balance states there is a positive correlation between the prioritizing parameters and the power consumption rate of the corresponding charging schemes. For example, for a certain grid frequency, batteries with higher priority would be charged faster or first.

Turning to Fig 2D, there is generally illustrated a charging criteria LUT usable for associating one or more charging schemes with values load-balance parameters and prioritizing parameters. Here, the specific charging schemes parameter(s) and prioritizing parameter(s) are not illustrated. Also, here a hysteresis parameter is indicated for each charging scheme. This parameter may for example designate a difference/delta between the frequency at which the charger should be triggered to operate according to a certain charging scheme and a frequency at which the charger should cease from operating according to that scheme.

It should be noted that according to some embodiments of the invention the charging criteria may include certain one or more criteria indicative of charging schemes with a negative power consumption rate. Namely, charging schemes at which power is drawn from the battery to the grid. For example, for certain overloaded grids states (e.g. low frequency values indicated by Fq parameter in Fig. 2A), a negative power consumption rate may be provided by the corresponding value(s) of the charging parameter(s) (e.g. negative value of the CCp parameter in Fig. 2A). To this end, the charging criteria may be configured such that negative power consumption rate is provided in accordance with values of certain prioritizing parameters such as SOC and EU parameters. The values of such parameters may be used to determine whether the battery is more than sufficiently charged for the expected usage of the vehicle, and in such cases to allow drawing power form the battery to the grid.

Reference is now made to Fig. 3 which is a block diagram 300 schematically illustrating a system for use in charging battery(ies) according to the invention. The system 300 may be implemented in a single charging unit/module or as a distributed system which certain modules thereof reside at different places (e.g. distributed between the charged device/EV/battery, a charger/charging-pole/station and a central control system). In cases where the system is implemented as a non distributed system, it may be installed in its entirety at a charging station/pole, or installed with the device to be charged (e.g. on board the onboard EV), and/or it may be implemented as a portable system for use in charging batteries from the grid .

System 300 includes an Electric Network Monitoring module 320 and a charging controller 330. The Electric Network Monitoring module 320 is associated with an electric network and adapted to provide data LBV indicative of the load balance state of the grid. The charging controller 330 is connectable to the Electric Network Monitoring module 320 and adapted for utilizing that data LBV to determine a suitable charging scheme SCH for use in charging a battery. Typically, according to some embodiments of the invention, system 300 also includes a Charging-Protocol module 310 operable for associating different load balance states of the electric grid (e.g. LBV data) with suitable charging schemes which are indicative of a certain characteristics of the charging operation. Charging-Protocol module 310 is configured and operable for providing data CRT indicative of one or more charging criteria associating one or more values of at least a load balance parameter (e.g. LBV data) with corresponding charging schemes. To this end, the Charging controller 330 may be connectable to the charging protocol module 310 for receiving therefrom data SCH indicative of the suitable charging scheme SCH. Alternatively or additionally, Charging controller 330 may be configured and operable for implementing the functionality of charging protocol module 310 internally; for example charging protocol module 310 may be included/integrated with the Charging controller 330.

According to some embodiments of the invention, the system 300 also includes a Prioritizing module 340 that is configured and operable for providing values of one or more prioritizing parameters associated with prioritized charging of batteries. In such embodiments the charging criteria CRT may also associate values of the prioritizing parameters with corresponding charging schemes.

Also, according to some embodiments of the invention, system 300 includes, or is associated with, a Battery Charging module 350. The Battery Charging module 350 is connectable to the Charging controller 330 and adapted for receiving therefrom operational instructions for charging a battery in accordance with the selected scheme. The operational instructions may be in the form of data and/or signals communicated to the Battery Charging module 350. The Battery Charging module 350 may be part of system 300 or it may be associated with a vehicle/device to be charged utilizing system 300.

As noted above, according to some embodiments of the invention improving the load balance state of the network may be achieved by utilizing charging schemes which may have negative power consumption rates. In such embodiments, the charging controller 330 may be configured to operate in accordance with the selected scheme for carrying out any of the following: provide power from the grid to the battery for charging the battery at a certain rate; and drawing power/current from the battery to the grid (e.g. to relieve an over-loaded grid state). To this end, the battery charging module 350 may be configured to enable control over the power consumption rate during charging and to enable drawing power/current from the battery. In this respect the charging controller 330 may be adapted to operate in accordance with the capabilities of the battery charging module 350.

For some types of power consuming utilities (e.g. some types of charging modules 350) the time required for modifying their operation to changing their power consumption rate is longer than a desired real-time response time that should be provided by system 300. Thus, according to some embodiments of the invention, in order to provide real-time response to changes in the grids load balance state, the system charging controller 330 is operable to selectively switch (ON/OFF) the current supply to such utilities in accordance with the state of the grid. Switching the current supply can be done extremely quickly and thereby provide real time response to the grid's load balance state. Optionally, meanwhile, after the power consuming utility had been disconnected, the charging controller 330 may operate modify its operation mode to comply with a desired power consumption rate. This operation may, in some cases, take longer then the desired system's response time and is thus made "off-line" after a first action of connecting/disconnection the utility has already been taken. Then, one the operational mode is modified in accordance with the charging criteria, the utility is reconnect again.

It should be noted that according to some embodiments of the invention system 300 or certain modules thereof may be implemented as a computerized system/circuit. To this end, system 300 may be associated with one or more processors and storage modules (not specifically shown in the figure). In this regards one or more modules of the system 300 may be implemented as software and/or hardware modules operating in association with the one or more processors and storage modules. In this regards, according to some embodiments of the invention, system 300 is configured for utilizing data communication for communicating with a control center 399 and/or with the electric power consuming utilities to be charged by the system (e.g. EV's or battery controllers) and/or with user identification devices. To this end, system 300 may also be associated with one or more data communication modules (not specifically shown in the figure). These may be for example Bluetooth (BT) and wireless-LAN (WIFI) communication modules and also near-field-communication (NFC) modules such as, radio-frequency- identification (RFID) .

The Electric Network Monitoring module 320 provides/determines data LBV indicative of the grid's load balance state. The Electric Network Monitoring module 320 may be for example connectable to the electric supply of the grid and configured for measuring certain electric parameters, such as the grid's frequency, indicative of the grid's load balance state. Alternatively or additionally, the Electric Network Monitoring module 320 may be adapted receive data/signals indicative of the load balance state. For example, the Network Monitoring module 320 may be associated with a data- communication module (e.g. modem) and adapted to communicate with a control center or grid/network information center for receiving therefrom the load balance state data LBV.

Charging-Protocol module 310 utilizes at least the data LBV indicating the load balance state of the grid to select a proper charging scheme SCH suited for charging a battery under the measured load balance conditions of the grid. Charging-Protocol module 310 may utilize the charging criteria CRT to determine suitable charging schemes for different load balanced states. As noted above, the charging criteria may include a rule, a formula and/or a LUT associating different values of the grid's frequency (or other load balancing parameters) with different charging schemes (e.g. charging parameters) having different power consumption rates.

According to some embodiments the Charging-Protocol module 310 may be adapted to determine and/or compute the charging criteria internally. Alternatively or additionally, Charging-Protocol module 310 may be adapted for communication with and another utility for receiving the charging criteria therefrom. In the latter case the charging criteria may be received and/or updated by a central control system 399 associated with system 300. Data communication may be carried out by utilizing a suitable data-communication module associated with system 300.

According to some embodiments of the invention, system 300 is configured for improving the load balance of the network/grid. This is associated with relieving excess power/current demand from the grid when the grid is over-loaded and increasing the power/current consumption when the grid is under-loaded. To this end the Charging- Protocol module 310 may be adapted for associating lower power consuming charging schemes for over loaded grid states (e.g. for low measured frequencies of the grid) and higher power consuming schemes for under-loaded states of the grid (e.g. for high grid frequencies).

System 300 may be configured for providing agile response to changes in the grid's load balance state with response time of less than few seconds and preferably less than 1 second. This may be achieved by configuring the Network Monitoring module 320 for real-time monitoring the load balance state of the grid (preferably by direct monitoring/measuring of the grids frequency) and providing data LBV indicative thereof. Charging controller 330 may then also be configured to operate in real time to respond to changes in the load balance state and select a suitable charging scheme SCHM for adjusting the charging power consumption of the charger module 350 accordingly and in real time. In order to provide real-time load-balancing responses it may also be advantageous to configure system 300 as a standalone utility that operates independently of other utilities thus allowing it to operate for optimizing the load balance state of the grid without using data communication in real-time. It should be noted that data communication may still be used in such configurations of system 300 for non-real-time (e.g. background) operations such as updating the charging criteria CRT and the values of prioritizing- and battery- parameters of the charged batteries.

According to some embodiments of the invention, the Charging Protocol module 310 is adapted for producing/computing one or more charging criteria CRT which associate different charging schemes (e.g. different charging parameters) with various values of the load balancing parameter of the grid and possibly with various values of the prioritizing parameters. Alternatively or additionally, Charging Protocol module 310 may adapted for obtaining/updating the charging criteria CRT and/or corresponding charging schemes from an external utility 399 such as control center. The Charging Protocol module 310 may be connectable to such external utility via wired or wireless communication. The Charging Protocol module may also be responsive to updates from the external utility 399. Such updates may include updates to the charging criteria CRT and/or updates to the charging schemes associated therewith. The updates may be provided from the external utility 399 for example in response to changes in a power consumption policy and/or in accordance with a state and/type of the vehicle/battery to be charged. To this end, the Charging Protocol module may also be configured to initiate request to receive updates to the charging criteria for charging specific battery/EV.

As noted above, grid performance and load balancing, together with provision of improved and more accurate power replenishment services, may be provided by selecting the charging schemes in accordance with at least some prioritizing- and/or battery- parameters. According to some embodiments of the invention, system 300 includes the Prioritizing module 340 which is responsive for storing and optionally receiving data indicative of one or more prioritizing-parameters and/or the battery- parameters of the battery/EV to be charged. The Prioritizing module 340 may be configured and operable to obtain such data, or portions thereof, via direct or indirect data communication with the vehicle/device carrying the battery and/or via communication with an external utility 399 (e.g. control center).

In cases where the control center 399 provides prioritizing and/or battery data PRI, it needs to be able to determine/identify the battery or vehicle to be charged by system 300. Such identifying data may be supplied to the control center 399 directly from the vehicle or by system 300. Thus, according to some embodiments of the present invention, system 300 further includes an identification module 360 configured and operable for allowing identification of the battery to be charged. To this end, data identifying the battery IDV may include for example any one of the following: identifying the battery itself and/or its type and/or identifying the device/vehicle carrying the battery and/or identifying a user of the battery. The identification module 360 may be associated with a communication module and/or a user input module (not shown) through which identification data IDV can be provided. For example the identification module 360 may utilize radio-frequency-identification (RFID) or near- field-communication (NFC) technologies to identify data IDV indicative of the battery and/or its user and/or a vehicle associated with the battery. Alternatively or additionally, the Identification module 360 may be associated with data communication networks such as Bluetooth (BT) or wireless-LAN (WIFI) and may be configured to communicate with a controller of the vehicle/battery for receiving therefrom Identification data IDV and possibly also prioritizing and battery data PRI.

Battery identification data IDV may be optionally used by the Prioritizing module 340 to determine prioritizing- or battery- parameters PRI. In such cases the Identification module may be connectable to the Prioritizing module 340 for communicating identification data IDV thereto.

Alternatively or additionally, according to some embodiments of the invention, the identification data IDV is communicated from the identification module 360 to the central control system 399. The central control system 399 may utilize the identification data IDV to determine prioritizing and/or battery data PRI to be communicated to the Prioritizing module 340.

Claims

CLAIMS:

1. A method for use in electric charging of batteries by an electric network comprising:

providing data indicative of one or more charging criteria associating one or more values of at least a load balance parameter of the electric network with charging schemes corresponding to said one or more values,

monitoring the electric network to determine a value of said load balance parameter in the network; and

utilizing said one or more criteria and said determined value to select a charging scheme to be used for charging a battery.

2. The method according to claim 1 wherein at least one of said charging criteria is additionally associating one or more prioritizing parameters, corresponding to prioritized charging of a battery, with a corresponding charging schemes; the method comprising obtaining prioritizing values corresponding to said one or more prioritizing parameters in a battery to be charged, and selecting the charging scheme in accordance with said prioritizing values and said determined value of the load balance parameter.

3. The method according to claim 2 wherein said prioritizing parameters comprise at least a state of charge (SOC) parameter indicative of the SOC of said battery to be charged.

4. The method according to claim 3 wherein a value of said SOC parameter is determined based on battery data received from onboard an electric vehicle at which said battery is installed.

5. The method according to claims 3 or 4 wherein a value of said SOC parameter is estimated based on battery-usage data indicative of at least one of the following: a previous SOC of the battery, battery service history data, and expected usage of the battery or a vehicle upon which said battery is installed.

6. The method according to any one of claims 2 to 5 wherein said prioritizing parameters comprise at least one of the following parameters: a service level (SL) parameter indicative of the service level to be provided to a vehicle upon which said battery is installed, and an expected usage (EU) parameter indicative of the expected power consumption to be used for driving said vehicle.

7. The method according to claim 6 wherein a value of at least one of said SL and EU parameters is at least partially determined based on data received from onboard said vehicle.

8. The method according to any one of claims 2 to 7 comprising obtaining information indicative of an identity of said battery to be charged and communicating said information to a control center for receiving therefrom at least one of said prioritizing values corresponding to said battery.

9. The method according to any one of the preceding claims, comprising obtaining information indicative of an identity of said battery to be charged and communicating said information to a control center for receiving therefrom at least one of said charging criteria to be used with said battery.

10. The method according to any one of the preceding claims, wherein said one or more charging criteria are selected to optimize load balancing in the electric network.

11. The method according to any one of the preceding claims, wherein said charging criteria associate over-load and under-load values of said load balance parameter, which correspond to over-load and under-load states of said electrical network, with the charging schemes having lower and higher power consumptions respectively thereby optimizing load balancing in the electric network.

12. The method according to any one of the claims 2 to 8, wherein for a given set of said prioritizing values, the charging criteria associate over-load and under-load values of said load balance parameter, which correspond to over-load and under-load states of said electrical network, with charging schemes having lower and higher power consumptions respectively thereby optimizing load balancing in the electric network.

13. The method according to any one of the preceding claims, wherein said load balance parameter corresponds to a frequency of electricity in the electric network

14. The method according to claim 13 comprising monitoring the frequency of said electric network to thereby determine a load balance state of said electric network, the frequency of said electric network being higher than a certain nominal frequency value of the network corresponding to the network operation in an under-load state, and the frequency of said electric network being lower than said nominal frequency corresponding to an over load state of the network.

15. The method according to any one of the preceding claims, wherein at least one of said charging schemes is indicative of a sequence of one or more charging cycles each including at least a charging period during which the battery is being charged and a recess period during which the battery is not charged.

16. The method according to claim 15, wherein said one or more charging cycles are periodic cycles with equal periods.

17. A system for use in charging batteries by an electric network comprising:

Charging-Protocol module configured and operable for providing data indicative of one or more charging criteria associating one or more values of at least a load balance parameter indicative of a load balance in the electric network with corresponding charging schemes;

Electric Network Monitoring module associated with an electric network and adapted for providing data indicative of a value of said load balance parameter in the network; and

Charging controller configured and operable for communication with said charging-protocol module and said electric network monitoring module, and adapted for utilizing said one or more charging criteria and said data indicative of the value of the load balance parameter, and selecting a charging scheme for use in operating a Battery Charging module.

18. The system of claim 17 comprising a Battery Charging module connectable to said Charging controller and adapted for receiving therefrom a signal indicative of the selected charging scheme and operating for charging an electric vehicle in accordance with the selected charging scheme.

19. The system according to claims 17 or 18 comprising a Prioritizing module adapted for providing prioritizing values corresponding to one or more prioritizing parameters associated with priority charging of batteries, at least one of said charging criteria associating one or more values of said prioritizing parameters with a corresponding charging scheme.

20. The system according to claim 19 wherein said Charging-Protocol module is adapted for receiving, from said Prioritizing module, one or more prioritizing values corresponding to a specific battery to be charged and for providing said data, indicative of said one or more charging criteria, in accordance with said prioritizing values.

21. The system according to claims 19 or 20 wherein said Charging controller is adapted for receiving, from said Prioritizing module, one or more prioritizing values corresponding to a specific battery and utilizing prioritizing values in determination of said selected charging scheme.

22. The system according to claim 21 wherein said vehicle prioritizing parameters comprise at least a state of charge (SOC) parameter indicative of the SOC of a battery to be charged.

23. The system according to claim 22 wherein said Prioritizing module is configured and operable for communicating with a control system on board said vehicle and receiving therefrom battery data indicative of a SOC of the battery.

24. The system according to claims 22 or 23 wherein said Prioritizing module is configured for estimating said SOC parameter based on at least one of the following: battery-usage data indicative of at least one of a previous battery SOC, battery service history data, and expected usage of a battery or a vehicle upon which said battery is installed.

25. The system according to any one of claims 19 to 24 wherein said prioritizing parameters comprising at least one of the following: a service level (SL) parameter indicative of the service level to be provided to a vehicle upon which said battery is installed, and an expected usage (EU) parameter indicative of the expected power consumption from said battery.

26. The system according to claim 25 wherein said Prioritizing module is configured and operable for communicating with a control system on board said vehicle and receiving therefrom data indicative of a value of at least one of said SL and EU parameters.

27. The system according to any one of claims 19 to 26 comprising an identification module adapted for obtaining information indicative of an identity of said battery and communicating said information to a control center; said Prioritizing module is adapted for receiving, in response, from said control center, at least one value corresponding to one or more of said prioritizing parameters.

28. The system according to any one of the claims 19 to 26 comprising an identification module adapted for obtaining information indicative of an identity of said battery and communicating said information to a control center; said Charging-Protocol module being adapted for receiving, from said control center, at least one of said charging criteria.

29. The system according to claims 27 or 28 wherein said information is indicative of the identity of at least one of the following: said battery, a vehicle upon which said battery is installed, and a user of said vehicle.

30. The system according to any one of the claims 17 to 29 wherein said Charging- Protocol module is operable for providing charging criteria adapted for optimizing load balancing in the electric network.

31. The system according to any one of the claims 17 to 30 wherein said charging criteria associate over-load and under-load values of said load balance parameter, which correspond to over-load and under-load states of said electrical network, with charging schemes having lower and higher power consumptions respectively thereby optimizing load balancing in the electric network.

32. The system according to any one of the claims 19 to 31 wherein said Charging- Protocol module is operable for providing, for a given set of said prioritizing values, charging criteria associating over-load and under-load values of said load balance parameter, which correspond to over-load and under-load states of said electrical network, with charging schemes having lower and higher power consumptions respectively thereby improving load balancing in the electric network.

33. The system according to any one of the claims 19 to 32 comprising a Frequency Monitoring module connectable to said electric network and adapted for measuring the load balancing parameter indicative of at least a frequency of electricity in the network and determining a frequency value corresponding to a load balance state for the network.

34. The system according to any one of the claims 17 to 33 wherein said Charging- Protocol module is adapted for providing data indicative at least one charging scheme comprising a sequence of charging cycles each including at least a charging period and a recess period.

35. The system according to claim 34 wherein said Charging controller is adapted for utilizing said charging criteria for selecting and utilizing said at least one charging scheme for charging said battery during charging periods of said charging cycles while not charging the battery during recess periods.

36. The system according to claim 35 wherein said Charging-Protocol module is adapted for providing charging schemes having different ratios between durations of the charging periods and durations of the charging cycles thereby providing charging schemes associated with different power consumption rates.

37. A system for use in charging batteries by an electric network comprising:

Charging-Protocol module providing data indicative of one or more charging criteria associating one or more values of at least a load balance parameter indicative of a load balance in the electric network with corresponding charging schemes associated with different power consumption rates, the charging scheme comprising a sequences of charging cycles including at least charging periods and recess periods having a different ratio between duration of the charging period and recess period, as compared to at least some other schemes.

Electric Network Monitoring module associated with an electric network and adapted for determining a value of said load balance parameter in the network; and

Charging controller adapted for utilizing said one or more charging criteria and said value of the load balance parameter to select a charging scheme to be used for operating a Battery Charging module to charge a battery in accordance with the selected charging scheme.

38. A method for use in charging batteries by an electric network comprising:

providing data indicative of one or more criteria associating values of frequency of electricity in the network with charging schemes, the charging schemes comprising charging cycles and being characterized by power consumption rates, the power consumption rate corresponding to a ratio between a duration a charging period of the charging cycle and a duration of the charging cycle; and

monitoring the electric network to determine an instantaneous value of the frequency of electricity in said network and utilizing said one or more criteria to select the associated charging scheme to be used for charging a battery.