CN101185235B - Method and apparatus for estimating current generated by AC generator of vehicle - Google Patents

Abstract

A method and device for estimating the current output by an alternator for a motor vehicle provide the calculation of an output value (IALT) that represents the current output by the alternator based on a first input value (lex) that represents an excitation current of the alternator, and based on a second input value (ROT) that represents the rotational speed of the alternator.

Description

Be used to estimate the method and apparatus of the current generated by AC generator of motor vehicle

Technical field

The present invention relates to a kind of method and apparatus that is used to estimate alternating current generator (alternator) (or alternator-starter) the institute output current of motor vehicle.The invention still further relates to the unit that is used to regulate voltage that this machine produces, be referred to as alternator regulator usually.

Background technology

The present invention is applied to require the slow-speed management of engine for example, considers during requiring to electrify to be put on by alternating current generator all types of vehicles of the complex management of the moment of torsion (this moment of torsion depend on alternating current generator to a great extent produced electric current) of Thermal Motor and/or vehicle battery charging balance simultaneously.In fact this method and device make might or provide the estimated value of current generated by AC generator to control unit of engine to other any computers that are built in vehicle.

The normal information that produces of alternating current generator is the level (referring to document WO 02/071570) of the duty ratio of excitation signal (PWM) and/or the exciting current for example measured by the battery tension adjuster.By computer this information is handled, thereby, derive the output current and the moment of torsion of alternating current generator thus.

Yet for the current value and moment of torsion of deriving alternating current generator thus and being produced, the duty ratio of excitation signal is inadequate information.This is because the resistance of rotor varies with temperature to a great extent, and what the duty ratio of excitation signal provided also is that the insufficient of exciting current describes, and estimates electric current and the moment of torsion that alternating current generator produced with it then.By the temperature (being easier to measure than the magnetic field winding temperature in rotating) that comprises adjuster, this problem can obtain part and remedy, and still, contacts directly because the temperature of the temperature of adjuster and magnetic field winding there is no, and this compensation is still approximate.

The current value and the moment of torsion that are produced therefrom deriving alternating current generator, exciting current have been the comparison sufficient information.This is because exciting current flows through the battery tension adjuster, and can measure (for example, via shunt or current mirror device) by the latter easily.Yet, use the computer of the vehicle of this information, in memory, must have the characteristic (becoming the form of record value in advance) that possibility is installed in all alternating current generators on this vehicle, this has used memory spaces a large amount of in the computer, and, also be a heavy task for motor vehicle manufacturers.

Avoid a kind of measure of this problem to be, alternating current generator self produces the current value of exporting, and this can realize with different modes.

Might use shunt or any other transducer directly to measure the electric current of exporting by alternating current generator.Yet by additional connection and parts, the mechanical structure of alternating current generator is very complicated with making.In addition, shunt must have about 200 amperes bear electric current and can overheated (only not having several watts) owing to must measure about several millivolts or ten millivolts voltage at the terminal place of shunt, this makes measures inaccuracy.

Also might be provided with the judgement of the alternating current generator output of finishing by the battery tension adjuster according to exciting current the pass.Yet, a kind of like this judgement, consistent with aforementioned prior art, require bigger memory capacity, the limited memory capacity of the microcontroller that combines with institute in the conventional voltage regulator is incompatible.In fact usually use complicate list form to realize this judgement.The temperature that this form must store rotating speed according to alternating current generator, exciting current, measured by adjuster and the output valve of battery tension.Even by carrying out interpolation between the value that provides at form, resource requirement also with less microcontroller that institute in the adjuster combines in available memory capacity incompatible.

Summary of the invention

Here propose solution of the present invention, according to the embodiment of the present invention, comprise according to the measurement of exciting current and according to the simplification isoboles calculating of alternating current generator and exporting.

According to first aspect, in fact the present invention proposes the method that a kind of estimation is used for the current generated by AC generator of motor vehicle, comprise second input value of representing first input value of alternating current generator exciting current and representing the alternating current generator rotating speed on the other hand according on the one hand, calculate the output valve of representative by current generated by AC generator, the calculating of this output valve may further comprise the steps:

(a) described first input value be multiply by mutually with the first multiplication coefficient K1 obtain first;

(b) long-pending with the electromotive force of described alternator and described second input value and the second multiplication coefficient K2 divided by obtaining second; And

(c) from first, deduct second, obtaining output valve,

Wherein

K1 is that a constant and expression are the output current of described alternating current generator when high rotating speed and the ratio between the exciting current; With

K2 is a constant and can controls as the variation in the output current of the function of rotating speed.

The introducing of correction coefficient makes and can adjust result of calculation, thereby reaches the actual value of predetermined alternating current generator output.

This method can realize in the unit (being referred to as battery tension adjuster or adjuster usually) of regulating voltage that alternating current generator produces.

For example, at step (b), can further make second input value determine that by first the non-zero added value increases.This first added value, it can be constant, for providing the output valve characteristic as the function of second input value, makes the x axle that may be implemented on second input value be shifted.By changing the value of representing the alternating current generator rotating speed, this makes might consider rotating speed thresholding (being referred to as initial velocity), is lower than the rotating speed thresholding that can not export any electric current on the alternating current generator principle.

Equally, at step (a), first input value is increased by the second non-zero added value.This second added value, it can be constant, for providing the output valve characteristic as the function of first input value, makes the y axle that might reach on first input value be shifted.This makes might be by changing the value of representing exciting current, the magnetic after effect of magnetic circuit during the compensation excitation.

Equally, the calculating of output valve can also comprise, in step (c) afterwards, and the interpolation of the 3rd non-zero added value.This 3rd added value, it can be constant, for providing the output valve characteristic as the function of first input value and second input value, makes the y axle that might be implemented on the output valve be shifted.This feasible efficient that especially may consider machine.

In one embodiment, second parameter that depends on the armature winding temperature of representing alternating current generator.Like this, the function of this temperature is regarded in the variation in the alternating current generator output as.

In a kind of modification, select one group of parameter, as the function of the parameter of the armature winding temperature of representing alternating current generator.This group parameter comprises the first related multiplication coefficient of step (a), related second multiplication coefficient, first added value, second added value and/or the 3rd added value of step (b).

In either case, represent the parameter of alternator armature winding temperature, for example can measure at for example adjuster place.With compare in the measurement at armature winding place, this measurement is carried out than being easier to, however the temperature at adjuster place is the function of the temperature at these winding places, provides between the two approximate.

In one embodiment, first input value (representative exciting current) is also measured at the place, unit that regulates voltage that alternating current generator produces.Therefore, might utilize method described in the aforementioned documents WO 02/071570.

A second aspect of the present invention relates to a kind of device that is used to estimate be used for the current generated by AC generator of motor vehicle, it comprises the parts that calculate the output valve of representing current generated by AC generator, be configured to according to first input value of the exciting current of representing alternating current generator on the one hand and second input value of representing the alternating current generator rotating speed on the other hand, calculate this output valve, the parts that wherein calculate output valve comprise:

(a) first calculating unit is configured to described first input value be multiply by mutually with the first multiplication coefficient K1 and obtains first;

(b) second calculating unit, the electromotive force that is configured to described alternator is the long-pending divided by obtaining second of K2 with described second input value and second multiplication; With

(c) the 3rd calculating unit is configured to deduct second from first, obtaining its output valve,

Wherein

K1 is that a constant and expression are the output current of described alternating current generator when high rotating speed and the ratio between the exciting current; With

K2 is a constant and can controls as the variation in the output current of the function of rotating speed.

This device can comprise the specific embodiment that is used to realize said method easily.

A kind of like this device can manufacture the form of the microcontroller of correct programming.

A third aspect of the present invention relates to a kind of unit that is used to regulate the voltage that alternating current generator produces of motor vehicle, comprises the device that is used to estimate current generated by AC generator according to second aspect.

In one embodiment, regulon also comprises the parts that calculate the moment of torsion that puts on the alternative electric generation arbor.This moment of torsion (perhaps torque) is by the mechanical torque of alternating current generator to the hot machine transmission of motor vehicle.Consider the feasible amount of fuel that might adapt to the hot machine of spirt by control unit of engine (for example) such as the oil spout computer.Therefore, might avoid because the problem due to the adjusting of charge in batteries electric current the unnecessary adjusting of hot machine.

For example, put on the moment of torsion of alternative electric generation arbor, according to useful moment of torsion, the moment of torsion relevant with electrical loss and with mechanical loss the summation of relevant moment of torsion calculate.

Useful moment of torsion can calculate according to the ratio of available power with the rotating speed of alternating current generator, and available power is calculated according to the product of the output voltage of alternating current generator and the level of current generated by AC generator (method according to first aspect is estimated).

The moment of torsion relevant with electrical loss can calculate according to the ratio of electrical loss with the alternating current generator rotating speed, and electrical loss for example utilizes the second order function of the estimated value (method according to first aspect is estimated) of current generated by AC generator to calculate.

The moment of torsion relevant with mechanical loss can utilize the quadratic function of alternating current generator rotating speed to calculate.

In another embodiment, regulon also comprises the parts that calculate the alternative electric generation engine efficiency.This efficient for example can be calculated according to the ratio of useful moment of torsion with the moment of torsion that puts on the alternative electric generation arbor.The level of efficiency of alternating current generator is provided, and may be useful to for example diagnosis and/or maintenance operation.

At last, a fourth aspect of the present invention relates to a kind of alternating current generator that is used for motor vehicle, comprises the unit that is used to regulate according to the voltage that alternating current generator produces of the third aspect.

Description of drawings

According to the reading of following explanation, other characteristics of the present invention and advantage will be more clear.Below explanation only is descriptive, and must read in conjunction with the accompanying drawings, wherein:

Fig. 1 is the simplification isoboles that is in the alternating current generator (or alternator-starter) in the running according to model instance;

Fig. 2 and Fig. 3 are first example and second examples of the armature model of illustration alternating current generator respectively

Figure;

Fig. 4 is the mesh coordinate curve chart of diagram characteristic, and this characteristic provides the output valve (representing the output of alternating current generator) of not considering added value as the function of second input value (representing the rotating speed of alternating current generator);

Fig. 5 is the mesh coordinate curve chart of diagram characteristic, this characteristic provides as the function of second input value (representing the rotating speed of alternating current generator) and has the output valve (representing the output of alternating current generator) of added value, make it might be near characteristic based on actual alternating current generator record, this characteristic provide as the function of alternating current generator rotating speed by current generated by AC generator;

Fig. 6 calculates the isoboles that is in the alternating current generator in the running with another example of the model simplified according to making;

Fig. 7 is shown in the block diagram that the temperature that is used to given armature winding in the situation of Fig. 6 model is selected the algorithm examples of multiplication coefficient and added value;

Fig. 8 is the block diagram that diagram adopts the algorithm examples of the Model Calculation alternating current generator output among Fig. 6;

Fig. 9 provides and trend curve figure as the relevant moment of torsion of the mechanical loss of the function of rotating speed, as calculating in the embodiments of the invention;

Figure 10 provides the trend curve figure that puts on the moment of torsion of alternative electric generation arbor as the function of rotating speed, as being calculated by the different value of exciting current in the embodiments of the invention; And

Figure 11 is the trend curve figure that provides as the alternative electric generation engine efficiency of the function of rotating speed, as being calculated by the different value of exciting current in the embodiments of the invention.

Embodiment

With reference to Fig. 1, provide the simplification isoboles of alternating current generator, wherein the various parameters under the alternate mode (altematingmode) do not have modelling.This is because for employed calculating in the microcontroller that is reduced at alternator regulator, for the true alternating current generator output of modelling, only considered equivalent continuous parameter (with electric current and voltage form).Therefore, the isoboles of simplification does not relate to any alternating current or voltage that needs rectification.Especially, induction coil (its impedance is proportional to rotating speed to be increased) also is proportional to the resistor replacement that rotating speed increases by its value.

The field coil 1 of alternating current generator (for example, rotor) is shown in the left hand portion of Fig. 1.The exciting current Iex of alternating current generator is by 11 simulations of DC current source.This electric current (very true) is for example measured by adjuster.Like this, in calculating, just considered as the variation in the magnetic field winding resistance of the function of temperature and the influence of magnetic field winding supply power voltage.

Armature 2 (for example stator) is shown in the middle part of Fig. 1.This armature comprises DC current source 22 and represents the value of armature actual resistance is the resistor 23 of R1.Current source 22 produces the DC electric current, and it is corresponding with the electric current (induced current) that alternating current generator is produced, as the function of exciting current Iex and alternating current generator rotating speed ROT.This current flows through resistor 23.Utilize any suitable transducer, for example the Hall effect sensor perhaps more simply according to its frequency and the proportional phase voltage of rotating speed, is measured rotating speed in the known manner.In fact, resistance R 1 depends on the temperature θ of armature winding.By the proper sensors that is arranged in these winding places, can measure this temperature.Yet, can see after a while, just may do like this when just the temperature of winding can not be convenient for measuring.

The right hand portion of Fig. 1 comprises: dc voltage source 31, the pressure drop VD in the bridge rectifier 3 of its analog AC generator; And dc voltage source 41, its simulation applies the load 4 of the output voltage V ALT of alternating current generator.The output voltage V ALT of alternating current generator is measured by adjuster, and is regulated by the latter.

See figures.1.and.2, the current value I ALT that current source 22 produces by alternating current generator output is as the function of exciting current Iex, rotating speed ROT and electromotive force E1 value.

According to following equation, this electromotive force E1 equal pressure drop VD in output voltage V ALT, the bridge rectifier and the pressure drop in the resistor R 1 and:

E1＝VALT+VD+R1×IALT (1)

As first approximation with when being in high rotating speed (about 20000 rev/mins), the output and the exciting current that can be estimated as alternating current generator are proportional.So, following equation is arranged:

IALT＝K1×Iex (2)

Wherein K1 is given multiplication coefficient, for example a constant.

On the other hand, alternator armature comprises the main stator induction coil 221 of value for L, and it partly or entirely is transformed into ground with electric current K1 * Iex's.This induction coil has impedance L ω, and is proportional with the rotating speed ROT of alternating current generator.Therefore, the electric current that induction coil 221 is shunted, less when high rotating speed, then bigger when the slow-speed of revolution (about 1000 to 1200 rev/mins) of alternating current generator.When low-down rotating speed (being lower than the beginning rotating speed, the rotating speed that begins to export as alternating current generator), all sensed coil 221 conversions of electric current K1 * Iex.Like this, this isoboles has been represented the too low and alternating current generator that can not export of rotating speed.

With reference to Fig. 3, the isoboles that under continuous mode, works only, the impedance L ω of induction coil 221 is replaced by its value and the proportional resistor R 2 of rotating speed ROT, according to following equation:

Lω＝K2×ROT (3)

Wherein K2 is given multiplication coefficient, for example a constant.

The electric current I L that is shunted by this resistor is provided by following formula:

$I_L=\frac{E1}{(\mathrm{ROT}\×K2)}---\left(4\right)$

The output IALT of alternating current generator, it equals IALT=Iex * K1-I _LSo,, provide by following equation:

$\mathrm{ILAT}=\mathrm{Iex}\×K1-\frac{E1}{(\mathrm{ROT}\×K2)}---\left(5\right)$

E1=VALT+VD+R1 * IALT wherein.

Resistance R 1 depends on the temperature θ of armature winding, according to following typical equation:

R1＝Ro×(1+αθ) (6)

Wherein θ refers to the temperature of armature winding, perhaps, if there is not this temperature, then refers to when the temperature of winding is difficult for measuring the temperature at battery tension adjuster place;

The resistance of armature when wherein Ro refers to about 0 ℃ of temperature; And

Wherein α shows fixed coefficient.

Variation in the bridge rectifier on the pressure drop VD is thought and can be ignored, thereby VD regards constant (typically, VD equals about 2 volts) as.Equally, the output voltage V ALT of alternating current generator also can regard constant (typically, VALT equals about 14.5 volts) as because regulate.So for the different value of exciting current Iex, equation (5) has provided the grid as the output characteristic of the function of rotating speed ROT thus.

As shown in Figure 4, the grid of this characteristic IALT=f (Iex) has the trend based on the property lattice of actual alternating current generator record.

In order to improve the model of alternating current generator, might selectivity constant, make it might make that the IALT value that goes out according to the Model Calculation that is proposed is accurately corresponding with the output of actual alternating current generator.For this purpose, introduce added value C3, C4 and C5, their following playing a role:

$\mathrm{LALT}=(\mathrm{Iex}+C3)\&times;k1-\frac{E1}{(\mathrm{ROT}+C4)\&times;\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="S2006800186610E00031.png,S2006800186610E00061.png"\; state="\{\{state\}\}">K</figure-callout>}2}+C5---\left(7\right)$

In a word, according to adopting the model that provides by above-mentioned three equatioies (1), (6) and (7), provide the value of Iex.The meaning of each multiplication coefficient and each added value (it is constant preferably) or act on as follows:

K1 is the output current IALT of alternating current generator when high rotating speed and the ratio between the exciting current Iexc.This coefficient has been considered ratio of revolutions between magnetic field winding and the armature and the flux loss between rotor and the stator;

K2 makes might be by making all or part of shunting ground connection of electric current (Iex+C3) * K1, and control is as the variation among the output current IALT of the function of rotating speed ROT;

C3 makes might be by changing the value of exciting current, the remanent magnetism of magnetic circuit influence when considering excitation;

C4 makes and might the x axle that characteristic IALT=f (ROT) is implemented on the tachometer value ROT be shifted; And

C5 makes and might the y axle that characteristic IALT=f (ROT) is implemented on the output valve IALT be shifted.

Constant C 3, C4 and C5 press 1 byte code separately, and work by addition.So they are easy to use in the microcontroller of 8 bits.

COEFFICIENT K 2 works by multiplication.Its value is coarse, and this multiplication can easily be carried out with the simple shift of value ROT+C4 usually.For this reason, select K2 that it is equated with 2 integral number power near institute's required value.As require, if higher precision proof be necessary, might use common hard wire to advance multiplication function in 8 8-digit microcontrollers.

COEFFICIENT K 1 also works by multiplication.On the other hand, COEFFICIENT K 1 must have exact value, and, must use common hard wire to advance multiplication function in 8 8-digit microcontrollers.

The selection of the value of multiplication coefficient K1 and K2 and constant C 3, C4 and C5 is by searching between the isoboles of alternating current generator and the correlation channeling conduct between the actual alternating current generator.A kind of situation is the calculating or the adjustment of the value of constant and coefficient, and IALT is accurately corresponding with the output of actual alternating current generator in the value of making.Might be according to carrying out by means of the method for continuous approximation.

Beginning might be ignored constant C 3, C4 and C5 (thereby C3=C4=C5=0), might ignore R1 (thereby E1=VALT+VD), and, can select K1, make K1=IALT/Iex.

Then, obtain the value of constant and coefficient by continuous approximation, the significant point on the curve of characteristic IALT=f (ROT), make might by simplify the easier acquisition of use expressed they.

For example, when high rotating speed (about 20000 rev/mins), the main induction coefficient of armature has very high value, and equivalent resistance R2 only shunts negligible electric current.In the case, equation (7) is write as:

IALT＝((Iex+C3)×K1)+C5 (8)

In addition, in starting point, IALT=0.In the case, equation (7) is write as:

$((\mathrm{Iex}+C3)\&times;K1)+\mathrm{<figure-callout\; id="5"\; label="C"\; filenames="S2006800186610E00041.png,S2006800186610E00061.png"\; state="\{\{state\}\}">C</figure-callout>}5=\frac{E1}{(\mathrm{ROT}+C4)\&times;K2}---\left(9\right)$

Should be noted that for higher accuracy some parameters of model (multiplication coefficient or added value) can dynamically be determined at least, that is to say, by making the alternating current generator effect.For example, might make the alternating current generator effect, make its electric current of exporting to definite value, and, determine added value C1 according to the measurement of the rotating speed ROT of correspondence.This operation can be formed on the adjustment that the assembly line end finishes or the part of setting.

The grid of characteristic IALT=f shown in Figure 5 (Iex) is corresponding to the grid among the Fig. 4 that crosses with selected constant and coefficient correction, with definitely corresponding with the characteristic of actual alternating current generator (being the TG15 alternating current generator from VALEO here).

The value that is adopted once or permanent storage in memory.Memory can be the inside ROM of the microcontroller of adjuster.

For the microcontroller of programming, make the on-stream value that provides IALT of energy to propose two kinds of solutions given below.

According to first solution, first step is to utilize equation (6) to calculate the resistance R 1 of armature.The value of R1 works to the second order of the output IALT of alternating current generator.In addition, if can not serviceability temperature transducer (rigorous environment), also just can't obtain the temperature of armature winding at these winding places.So, use the temperature θ (under the severe rugged environment, adjuster is usually placed in the back of alternating current generator cage) at adjuster place, may be also just enough.

Might directly utilize equation (6) to calculate R1, perhaps select a R1 value between the several values from be programmed in the ROM memory in advance, function (in this case, preferably provide four R1 values at least, be respectively applied for four different range of θ value) as θ.

Then, utilize equation (1) and (7) to calculate IALT.These equatioies (1) and (7) respectively comprise the value of IALT.Therefore, the calculating of IALT must be undertaken by continuous approximation, for example begins with IALT=0 in equation (1).

According to second solution, propose in the value of E1, directly not relate to pressure drop R1 * IALT (that is to say, select R1=0).

Therefore, equation (1) becomes:

E1＝VALT+VD (10)

And equation (7) is write as:

$\mathrm{IALT}=(\mathrm{Iex}+C3)\&times;K1-\frac{(\mathrm{VALT}+\mathrm{VD})}{(\mathrm{ROT}+C4)\&times;\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="S2006800186610E00031.png,S2006800186610E00061.png"\; state="\{\{state\}\}">K</figure-callout>}2}+C5---\left(11\right)$

So, advantageously, have only single equation to be used to calculate the value of IALT here, this makes by the processing of microcontroller convenient (no longer including any calculating by means of continuous approximation).On the other hand, must consider Temperature Influence by means of 5 constants and coefficient.

For this reason, best definition at least 4 group constant and coefficients, each group with the temperature range relevant (perhaps, better) of given adjuster if can measure the temperature of armature winding.

For example, corresponding with the threshold value of 50 ℃ and 100 ℃, might select 4 temperature ranges that provide in the following table 1.

Temperature range
	θ＜0℃?
0℃＜θ＜50℃?
	50℃＜θ＜100℃?
100℃＜θ?

Table 1

Therefore, for this example, constant and coefficient take 20 bytes of memory capacity (in ROM).In the form that is stored in like this in the memory, read two multiplication coefficients and three additional constants, its residing temperature range of armature winding (perhaps, being defaulted as the battery tension adjuster) when calculating IALT is corresponding.

Fig. 6 provides the isoboles according to the alternating current generator of this second solution (saving resistor R 1).

With reference to Fig. 7, the following describes according to the constant of the temperature of second solution armature winding given or adjuster and the algorithm examples that coefficient reads to being used for.The situation of 4 scopes of defined temperature value is corresponding in this example and the last table 1.

In initialization step 71, with variable θ ₀N is set at 0 with variable.

Then, in testing procedure 72, with the currency θ and the variable θ of temperature ₀Compare.

If θ＞θ ₀, so, in step 73, increase θ by 50 units ₀, then, in step 74, increase variable N (supposing that one group of constant is corresponding with 5 memory words that will read with coefficient in the ROM memory) by 5 units, and return testing procedure 72.

Otherwise, if θ＜θ ₀, so, in step 75,, read COEFFICIENT K 1 and the value of K2 and the value of constant C 3, C4 and C5 in the ROM memory at address AD R+N place, wherein ADR represents in the ROM memory address of first parameter (coefficient or constant) of first group.

Fig. 8 illustration is used for calculating according to second solution algorithm examples of the output IALT of alternating current generator, wherein uses for example by constant that algorithm obtained and coefficient among Fig. 7

In first step 81,,, calculate the value of E1 by the value of addition VALT and VD according to equation (10).The value of VALT and VD is known usually to the microcontroller of adjuster.In step 82, then calculate the median that is denoted as IR2, its with rotating speed ROT (microcontroller for adjuster is known usually) and memory in the C4 that reads corresponding with ROT+C4.Then, in step 83, value IR2 be multiply by the COEFFICIENT K 2 that reads in the memory.At last, in step 84, with the value (calculating in the step 81) of E1 divided by value IR2 (calculating in the step 83).

These steps 81-84 makes second of the equation (11) might obtain to provide alternating current generator output IALT.Should be noted that in the hardware of the microcontroller of adjuster, may be difficult to carry out providing item

The division of step 84, and this also is the reason that why can carry out by program.

In step 85, with the constant C in the memory that reads 3 value (can as explanation in the above-mentioned document WO 02/071570, measure) addition, with the median of the output IALT that obtains alternating current generator with exciting current Iex.Then, in step 86, the median of this IALT and COEFFICIENT K 1 in the memory that reads are multiplied each other.

These steps 85-86 makes first of equation (11) of the output IALT may obtain to provide alternating current generator.

In step 87, from first (when step 86 finishes, obtaining), deduct second (when step 86 finishes, obtaining), to obtain the new median of output IALT.Should be noted that for lower tachometer value (being lower than commencing speed) value that is obtained may be for negative.In the case, test makes and might change this negative value into null value.

For finishing, in step 88, with the median addition of the constant C in the ROM memory that reads 5, to obtain estimated value IALT by alternating current generator institute output current with the output IALT that obtains in step 87.

Should be noted that the order of step 81-84 on the one hand and on the other hand the order of step 85-86 can put upside down.Equally, step 88 can be carried out before step 87.In this case, constant C 5 can be added to second (when step 84 finishes, obtaining) or first (when step 86 finishes, obtaining).

The mathematic(al) representation that should be noted that the IALT that is provided by equation (7) can be expressed as different formula, but by using suitable coefficient and constant, different forms causes identical IALT value.

For example, COEFFICIENT K 2 can replace with 1/K2.In this case, equation (7) becomes:

$\mathrm{IALT}=(\mathrm{Iex}+C3)\&times;K1-\frac{\mathrm{<figure-callout\; id="1"\; label="E"\; filenames="S2006800186610E00071.png"\; state="\{\{state\}\}">E</figure-callout>}1\&times;K2}{(\mathrm{ROT}+C4)}+C5---\left(12\right)$

COEFFICIENT K 2 also can replace with K2/K1.In this case, equation (7) becomes:

$\mathrm{IALT}=(\mathrm{Iex}+C3-\frac{E1}{(\mathrm{ROT}+C4)\&times;K2})+\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="S2006800186610E00071.png"\; state="\{\{state\}\}">K</figure-callout>}1+C5---\left(13\right)$

Many possible combinations are arranged.Selection that is to say the form of the use most convenient of coefficient and constant, helps a kind of form that the microcontroller by the battery tension adjuster calculates most.

In an embodiment, the regulon of alternating current generator, adjuster just, not only comprise the parts that are used to estimate alternating current generator institute output current as mentioned above, and comprise the parts of the efficient ρ that calculates mechanical torque Ta, the available power Pu put on the alternative electric generation arbor and/or alternating current generator.

This is might calculate the electric current that alternating current generator is exported because the isoboles of simplifying makes, and might derive other characteristics of alternating current generator by additional calculations thus, such as the efficient of mechanical torque, power and alternating current generator.The calculating of torque T a and efficient p include with torque T u, the torque T e relevant with electrical loss and with mechanical loss relevant torque T m, they can obtain by additional calculations according to the obtainable information in adjuster place.

Compare with the calculating of independent output current IALT, these additional calculations require higher computing capability.Especially, often use multiplication and division, and hard wire advances microprocessor or microcomputer easily.

Useful torque T u depends on rotating speed ROT, and available power Pu is at the available electric power of output place of alternating current generator, and is provided by following equation:

Pu＝VALT×IALT (14)

From the available power Pu of such calculating, obtain useful moment of torsion by following column count:

$\mathrm{Tu}=\frac{\mathrm{Pu}}{\mathrm{ROT}}=\frac{\mathrm{VALT}\&times;\mathrm{IALT}}{\mathrm{ROT}}---\left(15\right)$

Electrical loss depends primarily on the resistance R 1 of armature.Therefore, the value of employed output current IALT preferably obtains according to the simplification isoboles among Fig. 1, because wherein relate to this resistance R 1.In this case, the calculating of output current IALT is carried out (for example by 4 iteration) by continuous approximation as previously mentioned.The torque T e relevant with electrical loss depends on power loss such as electrical loss Pe and rotating speed ROT.As first approximate, it is relevant to be estimated as about 1.5 volts pressure drop in joule loss in electrical loss Pe and the resistor R 1 and the bridge rectifier.As a result, torque T e can calculate according to following formula:

$\mathrm{Te}=\frac{\mathrm{Pe}}{\mathrm{ROT}}=\frac{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="S2006800186610E00071.png"\; state="\{\{state\}\}">R</figure-callout>}1\&times;{\mathrm{<figure-callout\; id="2"\; label="LALT"\; filenames="S2006800186610E00031.png,S2006800186610E00061.png"\; state="\{\{state\}\}">LALT</figure-callout>}}^2+1.5\&times;\mathrm{IALT}}{\mathrm{ROT}}---\left(16\right)$

If in the calculating of electrical loss, require higher precision, can proofread and correct the value of resistance R 1 according to the electric current I ALT of alternating current generator output, to consider the heating of armature winding.Also might consider resistive loss and magnetic loss in the winding of magnetic field, even by the exciting current Iex of the magnetic field winding taking-up of alternating current generator.

Mechanical loss is represented with torque T m, and it is the variable according to rotating speed ROT.As first approximate, because the loss of ventilate (ventilation), this torque T m is the quadratic function of this rotating speed.In other words, moment of torsion Ym can be calculated by following formula:

Tm＝P1×(ROT) ²+P1×(ROT)+P3 (17)

Wherein P1, P2 and P3 are the coefficients of the characteristic (the particularly loss of Tong Fenging, interior friction can be ignored) that depends on institute's concern alternating current generator, can know easily from adjuster manufacturer.

Curve among Fig. 9 provides the trend of the torque T m relevant with the mechanical loss that calculates according to said method.

Generally speaking, with electric torque T e relevant and the calculating of Tm, require to consider following coefficient respectively with mechanical loss:

The resistance R 1 of the stator winding relevant with electrical loss; And

FACTOR P 1, P2 and the P3 of the quadratic function relevant with the mechanical loss (mainly being the loss of ventilating) of alternating current generator.

Calculate as mentioned above after torque T u, Te and the Tm, then, might calculate the synthetic torque T a that puts on the alternative electric generation arbor.This be useful torque T u with relevant with the electrical-mechanical loss respectively torque T e and Tm's and:

Ta＝Tu+Te+Tm (18)

Curve among Figure 10 is the trend of the torque T a that calculates like this of the different value for exciting current.

The efficient ρ of alternating current generator is available power Pu and the ratio of the power that puts on axle (this product with corresponding torque Ta and rotating speed ROT is corresponding), the ratio of perhaps useful torque T u and a torque T a who puts on spool.So the efficient ρ of alternating current generator is calculated by one of following formula:

$\mathrm{\&rho;}=\frac{\mathrm{Pu}}{\mathrm{Ta}\&times;\mathrm{ROT}}=\frac{\mathrm{Tu}}{\mathrm{Ta}}---\left(19\right)$

The curve of Figure 11 provides the trend of the efficient ρ that the different value for exciting current calculates like this.

The current value I ALT that other information can be exported according to alternating current generator as required again calculates, and given above-mentioned information is as just example.

The alternator regulator that comprises the parts of realizing the foregoing description can center on such as Motorola 6805 ^TM8 8-digit microcontrollers cheaply produce.

Claims (25)

1. an estimation is used for the method for the current generated by AC generator of motor vehicle, comprise according to first input value of the exciting current of representing described alternating current generator on the one hand and second input value of representing the rotating speed (ROT) of described alternating current generator on the other hand, calculate the current generated output valve (IALT) of the described generator of representative, the calculating of wherein said output valve may further comprise the steps:

(a) described first input value be multiply by mutually with the first multiplication coefficient K1 obtain first (85,86);

(b) long-pending with the electromotive force (E1) of described alternator and described second input value and the second multiplication coefficient K2 divided by obtaining second (81-84); And

(c) from described first, deduct (87) described second, obtaining described output valve,

Wherein

K1 is that a constant and expression are the output current (IALT) of described alternating current generator when high rotating speed and the ratio between the exciting current (Iex); With

K2 is a constant and can controls as the variation among the output current IALT of the function of rotating speed ROT.

2. method according to claim 1, wherein, further make described second input value increase (82) by the first non-zero added value (C4), the described first non-zero added value (C4) is a constant and makes and might the x axle that characteristic IALT=f (ROT) is implemented on the tachometer value ROT be shifted.

3. method according to claim 1, wherein, further make described first input value by the second non-zero added value (C3) increase (85), the described second non-zero added value (C3) is a constant and makes that the remanent magnetism of magnetic circuit influences in the time of might considering excitation by the value that changes exciting current.

4. method according to claim 1, wherein, further make described output valve increase (88) by the 3rd non-zero added value (C5), described the 3rd non-zero added value (C5) is a constant and makes and might the y axle that characteristic IALT=f (ROT) is implemented on the output valve IALT be shifted.

5. method according to claim 1, wherein said second parameter (θ) that depends on the armature winding temperature of representing described alternating current generator.

6. method according to claim 1, wherein according to the parameter (θ) of armature winding temperature of the described alternating current generator of representative, select one group of parameter, second multiplication coefficient (K2), the first non-zero added value (C4), the second non-zero added value (C3) and/or the 3rd non-zero added value (C5) that are included in first multiplication coefficient (K1) that first step (a) works, work in second step (b).

7. method according to claim 5 is wherein represented the parameter (θ) of the armature winding temperature of described alternating current generator, measures at the place, unit that regulates by voltage that described alternating current generator produces.

8. method according to claim 1, wherein said first input value is measured at the place, unit that regulates by voltage that described alternating current generator produces.

9. device that is used to estimate be used for the current generated by AC generator of motor vehicle, it comprises the parts of the output valve (IALT) of calculating the described current generated by AC generator of representative, be configured to according to first input value (Iex) of the exciting current of representing on the one hand described alternating current generator and represent second input value (ROT) of the rotating speed of described alternating current generator to calculate described output valve on the other hand, the described parts that wherein calculate described output valve comprise:

(a) first calculating unit is configured to described first input value be multiply by mutually with the first multiplication coefficient K1 and obtains first (85,86);

(b) second calculating unit is configured to long-pending divided by obtaining second (81-84) with the electromotive force (E1) of described alternator and described second input value and the second multiplication coefficient K2; With

(c) the 3rd calculating unit is configured to deduct (87) described second from described first, obtaining its output valve,

Wherein

K1 is that a constant and expression are the output current (IALT) of described alternating current generator when high rotating speed and the ratio between the exciting current (Iex); With

K2 is a constant and can controls as the variation among the output current IALT of the function of rotating speed ROT.

10. device according to claim 9, wherein said second calculating unit is configured to further make described second input value to increase (82) by the first non-zero added value (C4), and the described first non-zero added value (C4) is a constant and makes and might the x axle that characteristic IALT=f (ROT) is implemented on the tachometer value ROT be shifted.

11. device according to claim 9, wherein said first calculating unit is configured to further make described first input value by the second non-zero added value (C3) increase (85), and the described second non-zero added value (C3) is a constant and makes that the remanent magnetism of magnetic circuit influences in the time of might considering excitation by the value that changes exciting current.

12. device according to claim 9, the described parts that wherein calculate described output valve also comprise, after described the 3rd calculating unit, further make the parts of described output valve by the 3rd non-zero added value (C5) increase (88), described the 3rd non-zero added value (C5) is a constant and makes and might the y axle that characteristic IALT=f (ROT) is implemented on the output valve IALT be shifted.

13. device according to claim 9, wherein said second parameter (θ) that depends on the armature winding temperature of representing described alternating current generator.

14. device according to claim 9, also comprise alternative pack, be configured to parameter (θ) according to the described alternator armature winding temperature of representative, select one group of parameter, comprise the multiplication coefficient (K1) that step (a) works, multiplication coefficient (K2), the first non-zero added value (C4), the second non-zero added value (C3) and/or the 3rd non-zero added value (C5) that step (b) works.

15. device according to claim 13 also comprises measurement component, is used at the place, unit that regulates voltage that described alternating current generator produces, and measures the parameter (θ) of the armature winding temperature of the described alternating current generator of representative.

16. device according to claim 9 also comprises a kind of parts, is used for measuring described first input value at the place, unit that regulates voltage that described alternating current generator produces.

17. regulate the unit of the voltage that alternating current generator produces be used for motor vehicle, comprise according to claim 9 any described device to the claim 16.

18. regulon according to claim 17 also comprises the parts that calculate the moment of torsion (Ta) that puts on described alternative electric generation arbor.

19. regulon according to claim 18 wherein puts on the moment of torsion of described alternative electric generation arbor, according to described useful moment of torsion (Tu), the moment of torsion (Te) relevant with electrical loss and with mechanical loss the summation of relevant moment of torsion (Tm) calculate.

20. regulon according to claim 19, wherein said useful moment of torsion (Tu) calculates according to the ratio of the rotating speed (ROT) of available power (Pu) and described alternating current generator, and described available power is according to the product calculating of the described estimated value (IALT) of the output voltage (VALT) of described alternating current generator and described current generated by AC generator.

21. regulon according to claim 19, wherein relevant with electrical loss described moment of torsion is according to the ratio calculating of described electrical loss (Pe) with the described rotating speed (ROT) of described alternating current generator, and described electrical loss utilizes the quadratic function of the estimated value of described current generated by AC generator (IALT) to calculate.

22. regulon according to claim 19, wherein relevant with described mechanical loss moment of torsion utilize the quadratic function of the rotating speed (ROT) of described alternating current generator to calculate.

23. regulon according to claim 17 also comprises the parts of the efficient (ρ) of calculating described alternating current generator.

24. regulon according to claim 23, wherein said efficient is calculated according to the ratio of described useful moment of torsion (Tu) with the described moment of torsion (Ta) that puts on described alternative electric generation arbor.

25. be used for the alternating current generator of motor vehicle, comprise unit according to claim 17 any described adjusting voltage that described alternating current generator produces to the claim 24.

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