EP1503394A2 - Electrical system for controlling contactors working in parallel - Google Patents

Abstract

A first contactor (1) has an electronic drive control (AS) to control the magnetic drives (K1,K2) of all contactors and two full-load (A1,A2) and two low-load (A10,A11) control inputs (CI). The low-load CI are bypassed by a time circuit (TS) that changes from a full-load for a specific holding period into a low-load condition when a control signal is applied to full-load CI.

Description

The invention relates to an electrical arrangement for driving operated in parallel Sagittarius. Contactors or electromagnetic switching devices are operated in parallel, by a high rated current to several designed for a lower rated current Sagittarius or more than a single contactor available Switch main current paths at the same time. In both cases, parallel operation is required Ensure that all individual shooters duly and switch off. In particular, in the first application is a symmetrical Power distribution to the contactors and a balancing whose switching dynamics sought and especially to avoid thermal overloading of one of Sagittarius and the associated risk of fire necessarily the same switching position the shooter demanded.

For the Gleichschaltung is previously a complex mechanical and electrical locking The shooter needed to avoid a thermal imbalance between the Protect or avoid a thermal overload of a single contactor. A deviating between the shooter switching position, for example, by a line break, a mechanical defect or a short-term voltage drop be caused. In the latter case, for tolerance reasons only one of the electromagnetic drives of the contactors fall off and the main power contacts of the associated contactor. Such a condition is definitely to avoid.

Currently, for such a parallel operation, the contactors are using external timing relays and locked via coupling contactors, resulting in a considerable additional material and Wiring effort required.

According to DE 35 28 948 A1 discloses a mechanical locking device is known, the the simultaneous switching on of two directly juxtaposed Sagittarius prevented. This locking device can not be on the beginning transferred parallel operation of multiple contactors.

From DE 299 09 901 U1 is an electronic drive control for a contactor drive known by the application of a DC or AC signal on high-current control inputs A1 and A2, the drive coil of the contactor drive is applied with a pulse width modulated DC voltage. The high current Control inputs take a relatively high to cover the drive power Input power on. The drive control is still low current, i. low-power control inputs A10 and A11 provided opposite to the high-current control inputs record a much lower input current. The low-voltage control inputs can be via internal or external resistors be connected to the high current control inputs. Then kick when applying a control signal to the high-current control inputs to the open low current control inputs a potential difference. To the drive To control, the low-voltage control inputs must be directly or over a resistor having a maximum value dependent on the magnitude of the control signal may not be connected. Otherwise, the contactor coil will, despite one not excited at the high-current control inputs pending control signal or de-energized with previous excitement.

The invention has for its object to exclude with little additional effort that of several parallel operated contactors only a few in the switched State are.

The object is achieved by the features of the independent claim solved during the dependent claims advantageous developments of Invention are to be taken. The arrangement according to the invention is characterized a self-contained compact structure, one opposite the individual Protect small additional material and manufacturing costs and the absence external additional components.

The two low-voltage control inputs of the only one belonging to the shooter Drive control are parallel of a series connection the individual Protect associated NO auxiliary contacts and one as active non-linear Two-pole timing circuit bypasses. When applying a control signal to the high current control inputs is via the low current control inputs triggered the hitherto high resistance timing circuit. The timer assumes a low resistance value for its holding period. Of the low resistance causes a current of sufficient height over the low-level control inputs, the drive control for tightening the Magnetic drives of all contactors and thus causes the closing of all main power contacts. The activated magnetic drives also close the associated normally-open auxiliary contacts. The serially arranged normally-open auxiliary contacts of all switched-on Contactors form a low-resistance bridge in parallel with the timing and take over Now in turn for the maintenance of the switched-state of Contactor required current through the low-voltage control inputs, so that without effect for the magnetic drives the timer after the end of their holding period again fell back into the high-impedance state. Disabling the drive control and thus the shutdown of all contactors is done in the usual way by removing the control signal to the high-current control inputs.

After applying the control signal, the magnetic drive of a single contactor should fail, then the associated NO auxiliary contact is not closed and as a result the open series connection of the NO auxiliary contacts flows after the falling back of the timer no current of sufficient height more about the low-current control inputs, whereupon all the magnetic drives via the drive control de-energized and thus all main power contacts are opened. The same thing occurs when, for some reason, the magnetic drive from the on state of a contactor drops. By opening the associated closer auxiliary contact the current drops below the required level via the low current control inputs Height, whereupon all contactors are switched off via the drive control. By the inventive arrangement is prevented from the combination of the parallel operated contactors permanently a condition can be taken in which not all contactors are switched on. This can not cause thermal overload a single contactor or permanently different switching states come between all main power contacts.

Due to the pulse width modulated DC excitation of the drive coils is the dependent on the switching position mutual inductance of the individual magnetic drives without significant importance, so that the drive coils of the contactors with advantage electrically be arranged parallel or in series. It is only necessary to make sure that the only drive control provides sufficient power to simultaneous tightening to ensure all magnetic drives.

To a minimum level of the terminal voltage for the timer during their To ensure retention period, is advantageously a first, forming a minimum resistance Voltage limiter arranged in series with the NO auxiliary contacts. For this purpose, a bidirectional Zener diode or Surpressordiode, a varistor or a pair of serially poled Z-diodes or suppressor diodes.

An advantageous embodiment of the timing circuit consists of the parallel connection of a Monoflops with a controlled by this semiconductor resistor and an upstream Full-wave rectifier. The full-wave rectifier is the input side with the low-current control inputs connected. The rectifier output voltage on the one hand supplies the parallel connection and on the other hand serves for the derivation of a Trigger signal for the monoflop. After bumping the monoflop controls the Semiconductor resistance from a high-impedance to a low-impedance state and after the end of its holding period in the high-impedance state back. At the low-current Control inputs this is considered a significant change in resistance and thus as significant, the drive control activating or deactivating Electricity change perceived.

An advantageous development of the aforementioned training is in series with the semiconductor resistor a second, forming a minimum resistance To arrange voltage limiters. This has the advantage of being above the monoflop after the transition of the semiconductor resistor in the low-resistance state continue to have sufficient supply voltage to ensure the monostable Condition is pending. For this purpose, a Z-diode, a Surpressor diode is suitable or a varistor.

The holding time of the timer must be chosen so large that the individual magnetic drives have enough time to put on and operate the NO auxiliary contacts. As appropriate, a holding period of about 100 ms has been found.

For the invention, it does not matter where the timer is located is. It makes sense that the timer TS in the drive unit one of the nichtansteuernden Sagittarius are integrated.

Figur 1:

die schematische Darstellung eines ansteuernden Schützes;

Figur 2:

die schematische Darstellung parallel betriebener Schütze mit der erfindungsgemäßen Anordnung zur deren Ansteuerung;

Figur 3:

das Schaltbild einer beispielhaften Zeitschaltung;

Figur 4:

beispielhafte Signaldiagramme;

Figur 5:

die Draufsicht auf parallel betriebene Schütze mit der teils schematisch dargestellten erfindungsgemäßen Anordnung.

Further details and advantages of the invention will become apparent from the following, explained with reference to figures embodiment. Show it

FIG. 1:

the schematic representation of a driving contactor;

FIG. 2:

the schematic representation of parallel operated contactors with the arrangement according to the invention for the control thereof;

FIG. 3:

the circuit diagram of an exemplary timing circuit;

FIG. 4:

exemplary signal diagrams;

FIG. 5:

the top view of parallel operated contactors with the arrangement of the invention partially shown schematically.

Fig. 1 shows a three-pole single contactor 1 with an electronic drive control AS for the magnetic drive K1 and operated by this main power contacts HA1. The drive control AS contains an essential part of a Leistungsund Control part LS. The details of the power and control LS can the in DE 299 09 901 U1 described in detail electronic drive control are removed, so that in the following only the essential for the invention Features and properties are set forth. To activate the magnetic drive K1 is a DC or AC signal to high current control inputs A1 and A2. Low-level control inputs A10, A11 are over relative High-impedance coupling resistors RK with the high-current control inputs A1, A2 connected in series with the coupling resistor connected to the control input A11 RK still an anti-parallel circuit of a light emitting diode LED and a normal diode DV0 is arranged. The LED and an associated phototransistor TVO are part of an opto-coupler. The low-voltage control inputs A10, A11 are connected externally. When applying a control signal in the form of a sufficiently high DC or AC voltage to the high-current control inputs A1, A2 is the power unit of the power and Control parts LS supplied with electricity and through the flow of current through the low-current Control inputs A10, A10 and the LED of the optocoupler of the control unit of the power and control LS activated in such a way that the drive coil of the Magnetic drive K1 loaded with a pulse width modulated DC voltage We, the magnetic drive K1 first to close the main power contacts HA1 activated and then stops in the closed state. By removing the control signal the high-current control inputs A1, A2 or by opening the connection between the low-level control inputs A10, A11 deactivate the power and Control part LS the magnetic drive K1, so that the main power contacts HA1 open. at unconnected low-level control inputs A10, A11 may be a control signal at the high-current control inputs A1, A2 not to activate the magnetic drive Lead K1.

For the combination shown in Fig. 2 of two parallel operated shooters 1 and 2 with associated magnetic drives K1 or K2 and main current contacts HA1 or HA2 becomes for the activating contactor 1 the single contactor described above with FIG used with electronic drive control AS. The other contactor 2 does not have its own drive control. His magnetic drive K2 is also from the power sufficiently designed drive control AS of the driving Contactor 2 operated. At the contactor combination shown are to increase the current carrying capacity in each case two belonging to the same contactor 1 and 2 respectively Main current paths on the one hand and the remaining main current paths both contactors 1, 2 on the other hand interconnected.

The drive coils of the magnetic drives K1, K2 form a parallel arrangement. The Low-level control inputs A10, A11 are connected in parallel via a series connection two normally-open auxiliary contacts HI1, HI2 and a first voltage limiter VL1 on the one hand and a two-pole in the form of a time circuit to be explained in more detail TS connected on the other hand. The first voltage limiter VL1 is exemplified as bidirectional Surpressor formed. The timer TS has the property that the resistance R measured across its terminals AX when applying an external Terminal voltage from a high value for a certain holding period in one significantly lower value and returns after the holding period the high value falls back. The normally open auxiliary contacts HI1, HI2 are each provided with a Magnetic drive K1 or K2 mechanically coupled and are when tightening or Falling back of the magnetic drives K1, K2 closed or opened. With the first Voltage limiter VL1 is achieved that with an applied control signal to the high-current control inputs A1, A2 the voltage between the low-current Control inputs A10, A11 and thus the voltage across the terminals AX of the Time switch TS despite closed NO auxiliary contacts HI1, HI2 not among the Voltage limiting value drops. The first voltage limiter VL1 should be selected that its voltage limit value is a proper working of the timer TS guaranteed.

When applying a DC or AC control signal to the high current Control inputs A1, A2 are connected to the low-level control inputs A10, A11 and thus at the terminals AX of the timer TS quickly a DC or Wechselanschlussspannung constructed, whereby the timing circuit TS to the transition is triggered in its state of low resistance. Due to the low resistance at the terminals AX flows via the high-current control inputs A10, A11 a current whose strength is at least so high that the drive control AS is activated to energize the magnetic drives K1, K2. The holding period of the timer TS must be so large that the response time of the drive circuit AS and the Operating times of the magnetic drives K1, K2 are covered. Go both magnet drives K1, K2 still during the holding period of the timer TS in the closed state In addition to the main contacts HA1, HA2, the two normally-open auxiliary contacts are also connected HI1, HI2 closed, so after falling back the timer TS in their high resistance state by the closed normally-open auxiliary contacts HI1, HI2 the required current through the low current control inputs A10, A11 for maintaining the active state of the drive control AS is guaranteed. Should one of the K1 or K2 solenoid drives not operate properly or not put on fast enough, then the timer circuit TS falls into theirs high-resistance state back without or before both normally-open auxiliary contacts HI1, HI2 are closed. The resistance measured via the terminals AX is in the rest position timer TS is too high to the active state to achieve or maintain the drive control AS. In practice For the resistance of the timing circuit, TS values of> 100 kΩ for the idle state and of <1kΩ for the excited state.

The timing circuit TS with the required resistance values can be compared with conventional ones Circuitry using CMOS technology devices realize. Fig. 3 shows a possible embodiment. The timer TS consists of a full-wave rectifier DV1, one fed and controlled by this Monoflop MF and the output of the full-wave rectifier DV1 bridging and reversible by monoflop MF semiconductor resistor TV1 in Shape of a CMOS transistor. The monoflop MF is in the usual way of a Timing device TI and two RC elements R2, C2 and R3, C3. As timer module TI is a CMOS circuit, for example, the type TL555C Texas Instruments, used. A resistor R1 serves as a series resistor and forms with the Full-wave rectifier DV1 and a Zener diode ZV2 a power supply for the Timing module TI. The supply voltage thus formed is through the capacitor C1 smoothed and suppressed. That of the resistor R3 and the capacitor C3 formed first RC element determines the holding period of the monoflop MF.

When the monoflop MF is activated, the semiconductor resistor becomes the holding time TV1 via a further series resistor R4 conductively controlled. Thus the supply voltage for the monoflop MF during the holding period not one of its proper functioning decreases, is in series with the semiconductor resistance TV1 a second voltage limiter in the form of another Zener diode ZV3 arranged, which ensures a minimum resistance for this series connection becomes. For a proper function of the timer module TI must be at a Voltage return for a short time of about 1 μs at the trigger input "trig" of the Timer modules TI the voltage levels are kept below 0.4V, which is due to the reached from the resistor R2 and the capacitor C2 formed second RC element becomes. Under a voltage return in this case is the voltage build-up to understand about the monoflop MF, which occurs when by applying a Control signal to the high-current control inputs A1, A2 a voltage to the Connections AX of the timer TS arrives. The through the second RC element R2, C2 given delay time is much smaller than that through the first RC element R3, C3 predetermined holding time. As a result, the timer module TI is after a shutdown the magnetic drives K1, K2 ready in a short time for a reclosure. This achieves a constant switching time even with fast switching sequences.

With the waveforms of FIG. 4, the operation of the invention Arrangement for driving the parallel operated contactors 1 and 2 explained again become. The resistance of the timer circuit TS remains after application of a control signal to the high-current control inputs A1, A2 for through the second RC element R2, C2 given delay time still at its high value. The voltage about the terminals AX takes approximately due to the high resistance Open circuit voltage via the low-current control inputs A10, A11 (see also Fig. 1). After this short delay time, the monoflop MF is triggered, and the resistance of the timing circuit TS takes the low for the holding period Value, whereupon the voltage at the terminals AX to a considerably smaller Value jumps. With a delay compared to the beginning of the holding period, which is essentially due to the structure of the drive control AS, begins the excitation of the magnetic drives K1 and K2. When tightening the magnetic drives K1, K2 are the individually assigned normally-open auxiliary contacts HI1 and HI2 closed. This happens with sufficient certainty before the falling back of the Time switch TS in the high-impedance state at the end of the holding period. After this Tightening of the magnetic drives K1, K2 is their excitation by the drive control AS reduced so far that the tightened state safely maintained becomes. By removing the control signal, the magnetic drives K1, K2 with System-related delay de-energized, whereupon the NO auxiliary contacts HI1, HI2 be opened again. Due to the lack of voltage at the low-level control inputs A10, A11 also the voltage at the terminals AX disappears.

Fig. 5 shows an expedient spatial embodiment of the parallel operated contactor combination. The contactors 1 and 2 are arranged side by side laterally, wherein in each case two adjacent main current paths via external connection bridges AB conductive connected to each other. In the rightmost, first contactor 1 is the drive control Integrated AS, the input side with terminals for the high-current Control inputs A1, A2 connected on the right side. On the left side are Terminals for the low-level control inputs A10, A11 provided. The drive control AS is the output side led to the first additional terminals E11, E12 and inside the contactor 1 with the coil terminals of the first magnetic drive K1 connected. The first normally-open auxiliary contact HI1 with the auxiliary switch terminals 13 and 14 are located below the terminals for the low-level control inputs A10, A11. The first voltage limiter VL1 connects externally or internally the low-level control input A10 with the auxiliary switch terminal 13 of the first Normally open contact HI1.

In the left, second contactor 2, the timing circuit TS is integrated, whose Connections AX are led out on the left side and are right next to the Terminals for the low-level control inputs A10, A11 are located. Below the Terminals AX is the second normally-open auxiliary contact HI2 with its auxiliary switch terminals 43 and 44. The lower of the two terminals AX is connected to the adjacent one low-level control input A11 and the auxiliary switch terminal 43 the second normally-open auxiliary contact HI2 whose other auxiliary switch terminal 44 with the remaining auxiliary switch terminal 14 of the first NO auxiliary contact HI1 is connected. This is one of the low-level control input A10 via the first voltage limiter VL1 as well as the normally open auxiliary contacts HI1, HI2 connected to the low-level control input A11 continuous connection, the is connected in parallel via the connections AX with the timing circuit TS. The coil connections of the second magnetic drive K2 are internal to second auxiliary terminals E21, E22 led on the left side of the second contactor 2, which is external to the adjacent first additional terminals E11, E12 are connected.

The magnetic coils of the magnetic drives K1, K2 do not necessarily have to be connected in parallel but can also be connected in series within the scope of the invention be. The invention is not limited to that of the main current paths respectively connected in pairs. Parallel operated contactors can increase the current phases also used with main current paths left separate become.

Obviously, more than two contactors can be operated in parallel with the invention become. For this purpose, the drive control LS must be provided in one of the contactors. All Contactors are each provided with a normally open auxiliary contact, with all normally open auxiliary contacts connected in series. The timer LS can be advantageous in one of other contactors are integrated.

Claims (10)

Electrical arrangement for controlling contactors operated in parallel with the following features : one of the contactors (1) has an electronic drive control (AS) provided with two high-current control inputs (A1; A2) for pulse-width-modulated DC excitation of the magnetic drives (K1; K2) of all contactors (1; 2), the drive control (AS) is further equipped with two low-current control inputs (A10; A11) connected resistively to the high-current control inputs (A1; A2) and for energizing the magnetic drives (K1; K2) upon application of a control signal to the high-current control inputs (A1 A2) are to be bridged by a connection not exceeding a maximum resistance, the low-current control inputs (A10, A11) are transited by a timing circuit (TS) which, when a terminal voltage at its terminals (AX) caused by the applied control signal, changes from a resistance state exceeding a maximum resistance to a resistance state for a given holding period , as well as by serially connected and by the contactors (1; 2) operated normally open auxiliary contacts (HI1, HI2) bridged. Electrical arrangement according to claim 1, characterized in that the drive coils the magnetic drives (K1, K2) are arranged in parallel. Electrical arrangement according to claim 1, characterized in that the drive coils the magnetic drives (K1, K2) are arranged serially. Electrical arrangement according to one of the preceding claims, characterized in that a first voltage limiter (VL1) is arranged in series with the auxiliary closing contacts (HI1; HI2). Electrical arrangement according to the preceding claim, characterized by a bidirectional Zener diode, a bidirectional Surpressordiode, a varistor or a series circuit of two mutually poled Z-diodes or Surpressordioden as a first voltage limiter (VL1). Electrical arrangement according to one of the preceding claims, characterized in that the timing circuit (TS) consists of an input-side full-wave rectifier (DV1), an adjoining one of the rectifier output voltage triggerable monoflop (MF) and arranged in parallel to the monoflop (MF ) reversible semiconductor resistor (VL1) consists. Electrical arrangement according to the preceding claim, characterized in that a second voltage limiter (ZV3) is arranged in series with the semiconductor resistor (VL1). Electrical arrangement according to the preceding claim, characterized by a Zener diode, a Surpressordiode or a varistor as a second voltage limiter (ZV3). Electrical arrangement according to one of the preceding claims, characterized in that the holding period of the timer (TS) is set to 75 ... 150 ms. Electrical arrangement according to one of the preceding claims, characterized in that the timing circuit (TS) within the or a not equipped with a drive control (AS) contactor (2) is arranged.

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