Device for determining the angular position of a rotor of a rotary electric machine and associated method, program product and computer-readable medium

Abstract

The invention relates to a device (100) for determining the angular position of a rotor (4) of a rotary electric machine on the basis of only three sensor signals delivered by position sensors (20), these signals being a first sensor signal, a second sensor signal, and a third sensor signal, this device comprising: - a circuit (104) for estimating the position of the rotor, in particular via implementation of a control loop, this circuit (104) delivering as output a signal representative of the position of the rotor, and - a circuit (102) for dynamically compensating for angular offset defects, this circuit receiving as input: a first input signal obtained from the first sensor signal, a second input signal obtained from the second sensor signal, and a third input signal obtained from the third sensor signal, this circuit (102) for dynamically compensating for angular offset defects delivering as output a signal that is transmitted to the circuit (104) for estimating the position of the rotor, this circuit (102) for dynamically compensating for angular offset defects being configured to: - dynamically determine the value of a first angular offset defect within one pair of input signals and the value of a second angular offset defect within another pair of input signals, - convert the system formed by the first input signal, the second input signal and the third input signal into a two-phase system via a mathematical transformation using the determined first and second angular offset defects in such a way that the two signals of this two-phase system have an angular offset of 90° between their fundamental components.

Description

[0001] DEVICE FOR DETERMINING THE ANGULAR POSITION OF A ROTOR OF A ROTATING ELECTRIC MACHINE, METHOD, PROGRAMMED PRODUCT AND COMPUTER-READABLE MEDIUM RELATING THERETO

[0002] The present invention relates to a device for determining the angular position of a rotor of a rotating electrical machine, as well as an assembly comprising such a determination device and such a rotating electrical machine.

[0003] The electrical machine is, for example, an alternator or an alternator-starter powered by a nominal voltage of 12V or 48V, or even higher. The electrical machine can also be a propulsion machine powered by a nominal voltage of 12V or 48V, or even higher, for example a voltage greater than 300V, for example 400V or 800V.

[0004] This electric machine can be integrated into a vehicle with hybrid or purely electric propulsion, for example an automobile. More generally, “vehicle” encompasses, within the meaning of this application, any form of mobility with purely electric, hybrid, thermal or other propulsion. “Vehicle” thus encompasses a machine rolling on land via four, three, two wheels or any other number of wheels, or a machine moving in the air or on water, or even in space.

[0005] The control of this electrical machine requires knowledge of the angular position of the machine's rotor. To do this, it is known, in the case of a three-phase synchronous machine, to use three signals provided by sensors, for example Hall effect, inductive type or at the end of the shaft with among these three signals, two pairs which are ideally offset by a target value of 120° (electrical or mechanical), depending on the type of sensor. The angular offset between the third and the first sensor must for example ideally be 120°, and the angular offset between the second and the first sensor must also ideally be 120°. The signals provided by these sensors are processed by a rotor position estimation circuit, for example via a control loop. This circuit provides an output signal representative of this rotor position.This measurement can then be used, for example, to control the inverter / rectifier interposed between the stator of this electrical machine and the electrical energy storage unit of the vehicle's on-board network, which is in particular a battery.

[0006] The accuracy of the position obtained at the output of the rotor position estimation circuit depends, among other things, on compliance with the value of 120° for the angular, or phase, offset between the pairs of position sensors. A fault in this offset, which is therefore different from 120°, is for example caused by imprecise positioning of the sensors on the electrical machine. However, an offset different from 120° can generate:

[0007] - second-order harmonics of the signal representing the rotor position obtained in the end,

[0008] - a bias (“offset” in English) on the position, -indirectly errors in compensating other harmonics in dynamics

[0009] These various errors, together or even individually, can ultimately cause current and torque oscillations in the electrical machine.

[0010] To avoid such problems, it is known to perform an end-of-line calibration operation, just before the electric machine is delivered to the customer. However, such an end-of-line calibration operation is complex and time-consuming, relying on an iterative extraction of Fourier series performed at constant speeds which are then subject to complex processing. Furthermore, such an end-of-line calibration operation is not possible when the electric machine is supplied by an equipment manufacturer independently of its power and control electronics.

[0011] There is therefore a need to remedy the aforementioned drawbacks.

[0012] The invention achieves this, according to one of its aspects, using a device for determining the angular position of a rotor of a rotating electrical machine on the basis of only three sensor signals provided by position sensors, these signals being a first sensor signal, a second sensor signal, and a third sensor signal, in particular offset by an ideal target value of 120°, the device comprising:

[0013] - a circuit estimating the position of the rotor, in particular via the creation of a control loop, this circuit providing at output a signal representative of the position of the rotor, and

[0014] - a dynamic angular offset fault compensation circuit, this circuit receiving as input: a first input signal from the first sensor signal, a second input signal from the second sensor signal, and a third input signal from the third sensor signal, this angular offset fault compensation circuit providing as output a signal transmitted to the circuit estimating the position of the rotor, this angular offset fault compensation circuit being configured to:

[0015] - dynamically determining the value of a first angular offset error within a pair of the input signals, i.e. between two of the first, second and third input signals, and the value of a second angular offset error within another pair of the input signals, i.e. between two of the first, second and third input signals,

[0016] - transforming the system formed by the first input signal, the second input signal and the third input signal into a two-phase system by a mathematical transformation using the first and second angular offset defect determined so that the two signals of this two-phase system have an angular offset of 90° between their fundamentals. The invention makes it possible to compensate for the angular offset defect within each pair of input signals, and this other than via a calibration operation at the end of the line. This angular offset defect compensation is carried out upstream of the rotor position estimation circuit, so that the latter receives as input two signals offset by 90° between their fundamentals.

[0017] Thus, the invention makes it possible, if the angular offset within each pair of input signals has a real value different from the target ideal value which is for example 120°, to compensate for the angular offset errors to provide at the input of the circuit estimating the position of the rotor two signals whose fundamentals are offset by 90°.

[0018] The number of sensor signals can be equal to the number of position sensors, for example, a position sensor providing only one sensor signal. Alternatively, the number of sensor signals can be different from the number of position sensors. For example, in the case where the sensors are used in differential mode, the number of position sensors is twice the number of sensor signals.

[0019] Where appropriate, the angular offset between the sensor signals may be equal, within the ratio of the number of pole pairs, to the angular offset between sensors from which these sensor signals originate. The angular offset between the sensor signals may be equal to the angular offset between sensors from which these sensor signals originate.

[0020] The invention is based on dynamic compensation, so that it makes it possible to detect and correct any position drift resulting from the aging of the machine. Although an end-of-line calibration operation is not necessary with the invention, the invention can make it possible, when such an operation is carried out, to verify that it has been carried out correctly.

[0021] The improvement in the accuracy of the signal representing the rotor position is obtained according to the invention using a simple solution, which is implemented in the determination device upstream of the circuit estimating the rotor position, in particular via a control loop. Furthermore, this solution has the following advantages:

[0022] - not to require oversampling,

[0023] - not to generate a delay in data acquisition, and therefore not to cause a risk of instability,

[0024] - not to involve a complex adaptive frequency filter,

[0025] - not to involve trigonometric functions or complex cross-correlations,

[0026] - not to require imposing a constant speed on the machine for a significant period of time, as required by a calibration operation at the end of the line,

[0027] - not to be a static solution, but a dynamic one. The solution according to the invention can provide the advantage of not involving a state observer, such as a Kalman filter.

[0028] The solution according to the invention can also provide the following advantages:

[0029] - be insensitive to electrical harmonics,

[0030] - be decorrelated from the bandwidth of the circuit estimating the rotor position,

[0031] The transformation of the system formed by the first input signal, the second input signal and the third input signal into a two-phase system may consist of applying to this system a matrix whose coefficients are all or part determined as a function of the first orthogonality defect or the second orthogonality defect. This matrix may differ from a Clarke or Concordia matrix, known for the transformation of a three-phase system into a two-phase system by the fact that its coefficients take into account the first and second angular offset defect. In the theoretical case, with a first zero angular offset defect and a second zero angular offset defect, this matrix may be a Clarke or Concordia matrix, where appropriate without using the third row of this matrix.

[0032] The signal representing the rotor position is, for example, an angle value relative to a reference position. This can be the angle characterizing the electrical position of the rotor or the angle characterizing the mechanical position of the rotor of the electrical machine.

[0033] The angular offset fault compensation circuit is arranged upstream of the rotor position estimation circuit, the latter notably implementing a control loop. The output of the angular offset fault compensation circuit is for example directly received at the input of the rotor position estimation circuit.

[0034] The angular mismatch compensation circuit can dynamically determine each angular mismatch between a pair of input signals based on the mechanical angular mismatch between the two sensor signals from which these input signals originate. This is the case, for example, when the sensor signals are provided by shaft-end sensors.

[0035] Alternatively, the angular offset fault compensation circuit may dynamically determine each angular offset fault between a pair of input signals based on the electrical angular offset between the two sensor signals from which these input signals originate. This is the case, for example, when the position sensors are inductive, Hall effect, or resolvers.

[0036] In all of the above, dynamically determining the first angular offset error may comprise multiplying the first input signal by the difference between the other two input signals to obtain a first product, and determining the second angular offset error may comprise multiplying the second input signal by the difference between the other two input signals to obtain a second product.

[0037] The first product may be processed by a first filter and the second product may be processed by a second filter. The first filter and the second filter may be different, the first filter being for example a filter of order 3 or order 2 and the second filter being in particular a filter of order 2 or 1.

[0038] Alternatively, the first and second filters may be identical, each being a 1st order, 2nd order or 3rd order filter.

[0039] At least one of the first and second filters is a Butterworth filter.

[0040] Each of the first filter and the second filter is, for example, a low-pass filter. As we will see later, these filters can have a constant cutoff frequency, or a variable cutoff frequency. For the same instant, or even for any instant, the cutoff frequency can be the same between the first filter and the second filter.

[0041] The first angular offset error can be obtained by performing a first linear combination of the output of the first filter and the output of the second filter, and the second angular offset error can be obtained by performing a second linear combination of the output of the first filter and the output of the second filter.

[0042] Compensation for the first and second angular offset faults can be performed for any rotor rotation speed.

[0043] Alternatively, the compensation for the first and second angular offset errors is performed only for a rotor rotation speed range, the dynamic angular offset error compensation circuit also receiving the rotor rotation speed as input. This rotor rotation speed is for example obtained at the output of the circuit estimating the rotor position. The angular offset error compensation is performed for example only above a minimum rotor rotation speed. Below this minimum rotation speed, which is for example 100, 200, 300, 400, 500, 600 or 700 rpm, no angular offset error compensation between the first and second signals is then performed, and the first, second and third input signals are directly transmitted to the circuit estimating the rotor position.Not performing angular offset compensation for low speeds can avoid the need to use overly selective low-pass filters.

[0044] Whether or not the angular offset compensation is performed over the entire operating range of the machine, when the first filter and the second filter are each a low-pass filter, the cutoff frequency of each filter can vary as a function of speed. This cutoff frequency can vary continuously or discontinuously, then successively occupying constant values. Varying each cutoff frequency, or at least one of these two cutoff frequencies such as that of the first filter only or that of the second filter only, can make it possible to achieve a compromise between accuracy and speed of the response of the angular offset compensation circuit.For example, higher first and second filter cutoff frequencies for lower speeds allow the first and second angular offset error values ​​to be determined quickly, while lower cutoff frequencies for higher speeds improve accuracy.

[0045] In all of the above, the rotor position estimation circuit may implement a control loop and subtract from the output signal of this control loop a position error signal determined on the basis of the first and second angular offset errors.

[0046] In all of the above, the device may also comprise a dynamic normalization circuit by the amplitude of the first harmonic of each sensor signal coming from a position sensor, this dynamic normalization circuit providing as output: the first, the second and the third input signal of the dynamic angular offset fault compensation circuit. This dynamic normalization circuit is thus arranged upstream of the angular offset fault compensation circuit. This dynamic normalization circuit is for example produced according to the teaching of application WO2021 / 121770.

[0047] The invention also relates, according to another of its aspects, to an assembly comprising:

[0048] - a rotating electrical machine for the propulsion of a hybrid or electric vehicle, and

[0049] - a control device for this electrical machine, comprising a determination device as defined above.

[0050] The rotating electrical machine is, for example, a synchronous machine, for example, a three-phase synchronous machine or a synchronous machine whose stator electrical winding defines a double three-phase system. The stator electrical winding is, for example, formed by wires or by conductive bars connected to each other.

[0051] In all of the above, the rotor may be a claw rotor. This rotor then comprises a first and a second nested pole wheel, the first pole wheel defining a series of claws of generally trapezoidal shape, each claw extending axially towards the second pole wheel, the second pole wheel defining a series of claws of generally trapezoidal shape, each claw extending axially towards the first pole wheel. A permanent magnet may be received between two consecutive claws circumferentially speaking for the rotor.

[0052] Alternatively, the rotor may be other than a claw rotor, for example comprising a stack of laminations or being a cage rotor.

[0053] In all of the above, the rotor may comprise any number of pole pairs, for example three, four, six or eight pole pairs.

[0054] In all of the above, the electrical machine may include a stator cooling circuit in which fluid such as air or liquid circulates. This liquid may be water or oil.

[0055] The rotor can be cooled by this same cooling circuit or by another cooling circuit in which air, or liquid such as water or oil, circulates.

[0056] The electric machine may have a mechanical rated power of between 4 kW and 35 kW, being for example 4 kW, 8 kW, 15 kW, 25 kW or 35 kW, or the electric machine may have a mechanical rated power of between 40 kW and 400 kW, being for example 40 kW, 80 kW, 100 kW, 150 kW, 180 kW, 200 kW, 300 kW or 400 kW.

[0057] This rotating electrical machine can be electrically powered from an electrical energy storage unit via an inverter / rectifier of the assembly, this inverter / rectifier allowing, depending on whether the electrical machine operates as a motor or as a generator, to charge an on-board network of the vehicle or to be electrically powered from this network.

[0058] The nominal voltage of the electrical energy storage unit can be 12 V, 48 V or have another value, for example another value higher than 300 V.

[0059] The rotating electrical machine may also include a pulley or any other means of connection to the rest of the vehicle's powertrain. The electrical machine is, for example, connected, in particular via a belt, to the crankshaft of the vehicle's thermal engine. Alternatively, the electrical machine is connected to other locations in the powertrain, for example, at the input of the gearbox from the point of view of the torque transmitted to the vehicle's wheels, at the output of the gearbox from the point of view of the torque transmitted to the vehicle's wheels, at the gearbox from the point of view of the torque transmitted to the vehicle's wheels, or on the front axle or the rear axle of this powertrain.

[0060] The rotating electrical machine is not necessarily a synchronous machine, but can be an asynchronous machine.

[0061] The invention also relates, according to another of its aspects, to a method for determining the angular position of a rotor of a rotating electrical machine on the basis of only three sensor signals provided by position sensors, in which a determination device as defined above is used.

[0062] All or part of what has been mentioned above still applies to this other aspect of the invention.

[0063] This determination method is for example integrated into a method for controlling the electric machine, in which the angular position of the rotor determined as above is used to control the motor torque and / or the current of the electrical energy storage unit.

[0064] This determination method can be implemented by a computer program product, which, when read by the electrical rotating machine control device, makes it possible to implement the steps of carrying out said method, said computer program product being able to be stored on a medium readable by said control device.

[0065] The invention may be better understood by reading the following description of a non-limiting example of its implementation and by examining the attached drawing in which:

[0066] [Fig.l] schematically represents in axial section an example of a rotating electrical machine to which the invention can be applied,

[0067] [Fig.2] shows in elevation another type of rotor than that of figure 1

[0068] [Fig.3] schematically represents the device for determining the position of the rotor of the machine according to a non-limiting example of implementation of the invention, [Fig.4] schematically represents a detail of figure 3,

[0069] [Fig.5] represents an example of a filter which can be used to realize the part of the compensation circuit of figure 3,

[0070] [Fig.6] schematically represents another detail of figure 3,

[0071] [Fig.7] schematically represents yet another detail of Figure 3, and

[0072] [Fig.8] corresponds to response curves allowing an effect of the invention to be illustrated.

[0073] Figure 1 shows a polyphase rotating electrical machine 1, in particular for a motor vehicle, to which the invention can be applied.

[0074] This rotating electrical machine can form an alternator or an alternator-starter of the vehicle. This rotating electrical machine can be powered via a power electronic component 9 comprising an inverter / rectifier by a battery whose nominal voltage is 12 V or 48 V or a value greater than 300 V, for example.

[0075] The rotating electrical machine 1 comprises a casing 2. Inside this casing 2, it further comprises a shaft 3, a rotor 4 integral in rotation with the shaft 3 and a stator 5 surrounding the rotor 4. The rotational movement of the rotor 4 takes place around an axis X. In this example, the casing 2 comprises a front bearing 6 and a rear bearing 7 which are assembled together. These bearings 6, 7 are hollow in shape and each centrally carry a respective ball bearing 10, 11 for the rotational mounting of the shaft 3.

[0076] A pulley 12 is in the example considered fixed on a front end of the shaft 3, at the level of the front bearing 6, for example using a nut resting on the bottom of the cavity of this pulley. This pulley 12 makes it possible to transmit the rotational movement to the shaft 3 and it can be connected via a belt to the crankshaft of the thermal engine of the vehicle.

[0077] The rear end of the shaft 3 carries, here, slip rings belonging to a collector and connected by wire connections to the winding. Brushes belonging to a brush holder 8 are arranged so as to rub on the slip rings.

[0078] The front bearing 6 and the rear bearing 7 may further comprise substantially lateral openings for the passage of air in order to allow the rotating electrical machine to be cooled by air circulation generated by the rotation of a front fan 13 on the front dorsal face of the rotor 4, i.e. at the level of the front bearing 6 and of a rear fan 14 on the rear dorsal face of the rotor, i.e. at the level of the rear bearing 7.

[0079] In this embodiment, the stator 5 comprises a body 15 in the form of a stack of sheets provided with notches, for example of the semi-closed or open type, equipped with notch insulation for mounting the polyphase electrical winding of the stator. Each phase comprises a winding 16 passing through the notches of the body 15 and forming, with all the phases, a front bun and a rear bun on either side of the body of the stator. The windings 16 are for example obtained from a continuous wire covered with enamel or from bar-shaped conductive elements such as pins connected together. The electrical winding of the stator is for example three-phase, then implementing a star or delta assembly whose outputs are connected to the power electronic component 9.

[0080] The rotor 4 of Figure 1 is a claw rotor. It has two pole wheels 17. The first pole wheel 17 is turned towards the power electronic component 9 while the second pole wheel 17 is turned towards the pulley 12.

[0081] Each of the pole wheels 17 comprises a base 18 extending radially on either side of the axis X, the wheel defining a series of claws 19 of generally trapezoidal shape. Each claw of a pole wheel 17 extends axially towards the other pole wheel from a base arranged on the radially outer periphery of the base 18.

[0082] The rotor 4 also comprises, between the radially inner portions 20 and the claws 19, a coil wound on a coil insulator 22.

[0083] The rotor 4 may also comprise permanent magnets (not shown) interposed between two neighboring claws 19 at the outer periphery of the rotor. Alternatively, the rotor 4 may be devoid of such permanent magnets.

[0084] The rotor 4 may also be different from that shown in Figure 1, being for example formed by a stack of sheets, as shown in Figure 2.

[0085] The number of pole pairs defined by the rotor 4 can be any, for example three, four, six or eight.

[0086] The machine also comprises sensors 20 for measuring the position of the rotor 4, for example three or two Hall effect sensors, grouped in the same plastic housing and arranged in such a way that, among these sensors 20, two pairs of sensors have an electrical angular offset whose ideal target value is 120°. Thus, a first angular offset between the first and third sensors has a target value of 120° and a second angular offset between the first and second sensors has a target value of 120°.

[0087] These sensors are for example positioned at the rear bearing 7 of the machine and they interact with a magnetic target integral with the rotation of the rotor.

[0088] The sensor signals provided by these three sensors 20 are used by a device for controlling the rotating electrical machine 1, comprising a device 100 for determining the angular position of the rotor 4. The device for controlling the rotating electrical machine 1 may be a computer, for example a microcontroller, or an integrated circuit, for example an EPGA or an ASIC, capable of receiving electrical signals and processing them, in particular the sensor signals 20.

[0089] The device 100 for determining the position of the rotor 4 will now be described with reference to figures 3 and following.

[0090] In the example of figure 3, the sensor signals provided by the three sensors 20 drive a dynamic normalization circuit 105 by the amplitude of the first harmonic of each signal from a position sensor 20. This circuit 105 is for example as described in application WO2021 / 121770.

[0091] As can be seen in Figure 3, the output signals of this circuit 105 form:

[0092] - a first input 110 for a circuit 102 for dynamic compensation of angular offset defect which will be described later, and

[0093] - a second input 111 for circuit 102.

[0094] In an example not shown, the circuit 105 is not present, so that the sensor signals provided by the three sensors 20 directly drive the dynamic angular offset fault compensation circuit 102.

[0095] The output of the circuit 102 in the example describes a circuit 103 for compensating for the bias existing in the signals from the circuit 102, this circuit 103 also receiving as input a register 113 storing predefined bias values. The circuit 103 performs, for example, an averaging of the samples.

[0096] The output of the bias compensation circuit 103 in the example considered drives a circuit 104 estimating the rotor position. This circuit 104 here implements a rotor position control loop 4 (“PTL” in English). As can be seen in FIG. 3, a position error signal 115 determined by the circuit 102 on the basis of the determined angular offset errors, as will be explained below, is subtracted from the signal at the output of the control loop. The result of this subtraction forms the output of the circuit 104 and corresponds to the signal representative of the rotor position. This signal also corresponds to the output of the device 100.

[0097] An example of a circuit 102 for dynamic compensation of angular offset defect will now be described in more detail with reference to FIGS. 4 to 7.

[0098] This circuit 102 includes a block 200 for dynamically determining:

[0099] - the value of a first angular offset defect within a pair of input signals respectively from sensor signals supplied to position sensors 20, i.e. between two of the first, second and third input signals which are present on the first input 110, and

[0100] - the value of a second angular offset defect within another pair of input signals respectively originating from sensor signals supplied by position sensors 20, i.e. between two others among the first, second and third input signals which are present on the first input 110.

[0101] The angular offset error between two input signals of the dynamic compensation circuit 102 is in the example considered equal to the angular offset between the two sensor signals from which these two input signals respectively originate.

[0102] An exemplary embodiment of this block 200 is shown in FIG. 4. In this example, the dynamic determination of the first angular offset error comprises multiplying the first input signal by the difference between the other two input signals to obtain a first product, and the determination of the second angular offset error comprises multiplying the second input signal by the difference between the other two input signals to obtain a second product.

[0103] The first product is then processed by a first filter 212 and the second product is processed by a second filter 213. The first filter 212 and the second filter 213 may be different, the first filter 212 being for example a filter of order 3 or order 2 and the second filter 213 being in particular a filter of order 2 or 1.

[0104] Alternatively, the first and second filters may be identical, for example each being a 1st order, 2nd order or 3rd order filter.

[0105] Each of the first filter 212 and the second filter 213 is for example a low-pass filter produced via a Butterworth filter of order 2, as represented in a non-limiting manner in FIG. 5.

[0106] Each of the low-pass filters 212 and 213 may have a cutoff frequency that varies depending on the rotational speed of the rotor. For example, this frequency varies piecewise, taking higher values ​​for low rotational speeds and decreasing stepwise as the rotational speed increases. For any instant, the cutoff frequency is for example the same between the first filter 212 and the second filter 213.

[0107] Alternatively, each filter 212 and 213 may have a constant cutoff frequency.

[0108] The first angular offset defect is then obtained by performing a first linear combination of the output of the first filter 212 and the output of the second filter 213. This linear combination is for example a simple sum, the two filter outputs being simply added.

[0109] The second angular offset defect is here obtained by performing a second linear combination of the output of the first filter 212 and the output of the second filter 213. The output of the first filter is here multiplied by a gain 215, for example equal to 2, before being summed to the output of the second filter 213.

[0110] At output 120 of this block 200, a first angular offset fault value is thus obtained dynamically within a pair of input signals among the three input signals, and a second angular offset fault value within another pair of input signals among these three input signals.

[0111] In the example considered, the block 200 has another input 206. This input 206 corresponds to an activation signal for the block 200. Indeed, in an advantageous embodiment, the compensation for each angular offset defect is not carried out in the device 100 for any rotation speed of the rotor, but it is only carried out beyond a minimum rotor rotation speed, for example beyond 100, 200, 300, 400, 500, 600 or 700 rpm. When the activation signal 206 is received by the block 200, the latter proceeds to determine the value of the first angular offset defect and the second angular offset defect. In practice, and although not shown, the circuit 102 can then receive as input a signal representative of the rotation speed of the rotor, and generate or not the activation signal 206 depending on the value of this rotation speed.

[0112] The output 120 of the block 200 is on the one hand received as input to a block 201 for determining a mathematical transformation of the three-phase system from the three sensors 20 into a two-phase system. This block consists of determining the coefficients of a Clarke or Concordia matrix taking into account the first angular offset defect and the second angular offset defect existing within the two pairs of input signals.

[0113] As can be seen in Figure 6, algebraic operations (products, sums, etc.) are performed on the first angular offset error and on the second angular offset error, and constants are added in order to obtain a transformation matrix which is here a 3*2 type matrix. Part of the coefficients of this matrix is ​​a function of the first angular offset error S02i and another part of the coefficients of this matrix is ​​a function of the second angular offset error 5031.

[0114] In the case where the first and second angular offset defects have small values, for example less than 10°, this matrix according to equation [Math. 1] can be simplified to the first order to a matrix according to equation [Math. 2] as below:

[0115] In the ideal case where the first angular offset error is zero and the second angular offset error is zero, the matrix determined by block 201 would be a Clarke matrix simplified up to the angle sign convention, with the third row not used as follows according to equation [Math. 3] below:

[0116] The matrix thus determined constitutes the input 112 of a block 202 also receiving the input 110 grouping the first input signal, the second input signal and the third input signal of the circuit 102.

[0117] This block 202 proceeds to the transformation of the three-phase system present on the input 110, this system being formed by the first input signal, the second input signal and the third input signal, into a two-phase system by the application of the matrix on the input 112. This two-phase system is formed by two signals not presenting any orthogonality error, at least between their respective fundamentals.

[0118] The two signals at the output of block 202 have, for example, an angular offset of 90° electrically or 90° mechanically, depending on the type of sensors 20 used.

[0119] The output 120 of the block 200 is also received as input to a block 203 whose output forms the signal 115 present in the circuit 104 for determining the position of the rotor, as already described with reference to FIG. 3. An example embodiment of this block 203 is shown in FIG. 7.

[0120] This block 203 consists of applying a gain 220 to the difference between the two angular offset defects determined by block 200, the value of which is for example 1 / 2.

[0121] Figure 8 represents on the same time scale on the abscissa:

[0122] - on a graph 300 the evolution of the rotation speed of the rotor of the electric machine as provided by the device 100,

[0123] - on a graph 301 the evolution of the signals at the input of the circuit 102 for dynamic compensation of angular offset fault, each coming from one of the position sensors 20, and

[0124] - on a graph 302 the evolution of the value determined by the block 200 of the circuit 102 for the first angular offset fault and for the second angular offset fault.

[0125] In this example, the electrical angular offset between the second input signal and the first input signal of circuit 102 is not 120° but has a first angular offset fault value of -2°, and the electrical angular offset between the third input signal and the first input signal of circuit 102 is not 120° but has a second angular offset fault value of 7°.

[0126] The dynamic angular offset defect compensation circuit 102, an example of implementation of which has been described above, is started at an instant to.

[0127] We observe by observing:

[0128] - curve 302 that the values ​​of -2° and 7° are obtained for the first and second angular offset defect in less than 100ms, and

[0129] - curve 300 that the estimated rotation speed improves after compensation for angular offset defects, as evidenced by the disappearance of second-order harmonics.

[0130] The invention is not limited to the implementation example which has just been described.

[0131] In particular, the dynamic angular offset fault compensation circuit 102 can act independently of the rotational speed of the rotor, i.e. from the start of the electrical machine. In the latter case, the cut-off frequency of each filter 212 and 213 can remain constant. Alternatively, in the latter case, the cut-off frequency of each filter 212 and 213 can vary, as described above. The implementation of the determination of the angular position of the rotor 4 can be carried out by a computer program product, which, when executed by the control device of the rotating electrical machine 1, makes it possible to carry out the method of determining the angular position of the rotor 4 of the rotating electrical machine 1 on the basis of the three sensor signals 20 provided by position sensors, as described with reference to Figures 3 to 8.

[0132] This computer program product can be recorded on a storage medium readable by the control device in order to carry out the implementation of the determination of the position of the rotor 4.

Claims

Claims 1. Device (100) for determining the angular position of a rotor (4) of a rotating electrical machine on the basis of only three sensor signals provided by position sensors (20), these signals being a first sensor signal, a second sensor signal, and a third sensor signal, offset by an ideal target value of 120°, device comprising: - a circuit (104) estimating the position of the rotor, in particular via the creation of a control loop, this circuit (104) providing at output a signal representative of the position of the rotor, and - a circuit (102) for dynamic compensation of angular offset fault, this circuit receiving as input: a first input signal from the first sensor signal, a second input signal from the second sensor signal, and a third input signal from the third sensor signal, this dynamic compensation circuit (102) for angular offset fault providing as output a signal transmitted to the circuit (104) estimating the position of the rotor, this dynamic compensation circuit (102) for angular offset fault being configured to: - dynamically determining the value of a first angular offset error within one pair of input signals and the value of a second angular offset error within another pair of input signals, - transforming the system formed by the first input signal, the second input signal and the third input signal into a two-phase system by a mathematical transformation using the first and second angular offset defect determined so that the two signals of this two-phase system have an angular offset of 90° between their fundamentals.

2. Device according to claim 1, in which the transformation of the system formed by the first input signal, the second input signal and the third input signal into a two-phase system consists of applying to this system a matrix of which all or part of the coefficients are determined as a function of the first angular offset defect (5021) or the second angular offset defect (5031).

3. Device according to claim 1 or 2, each angular offset defect between a pair of input signals determined dynamically by the circuit (102) being linked to the mechanical angular offset between the two sensor signals from which these input signals originate.

4. Device according to claim 1 or 2, each angular offset defect between a pair of input signals determined dynamically by the circuit (102) being linked to the electrical angular offset between the two sensor signals from which these input signals originate.

5. Device according to any one of the preceding claims, wherein the dynamic determination of the first angular offset error (ÔO21) comprises the multiplication of the first (200) input signal by the difference between the two other input signals to obtain a first product, and wherein the determination of the second angular offset error (ÔO31) comprises the multiplication of the second (201) input signal by the difference between the two other input signals to obtain a second product.

6. Device according to claim 5, in which the first product is treated by a first filter and the second product is treated by a second filter, at least one of the first (212) and the second filter (213) being in particular a Butterworth filter.

7. Device according to claim 6, wherein the first angular offset error (5021) is obtained by performing a first linear combination of the output of the first filter (212) and the output of the second filter (213), and wherein the second angular offset error (5031) is obtained by performing a second linear combination of the output of the first filter (212) and the output of the second filter (213).

8. Device according to any one of the preceding claims, in which the fault compensation of each angular offset is carried out for any rotational speed of the rotor.

9. Device according to any one of claims 1 to 7, in which the fault compensation of each angular offset is carried out only for a range of rotation speed of the rotor, the dynamic angular offset fault compensation circuit (102) also receiving as input the rotation speed of the rotor.

10. Device according to any one of claims 4 to 6 and according to claim 9, each of the first filter (212) and the second filter (213) being a low-pass filter, and the cut-off frequency of each filter (212, 213) varying as a function of the speed, in particular decreasing when the speed increases.

11. Device according to any one of the preceding claims, in which the circuit (104) estimating the position of the rotor implements a control loop and subtracts from the signal at the output of this control loop a position error signal (115) determined on the basis of the first and second angular offset fault.

12. Device according to any one of the preceding claims, further comprising a circuit (105) for dynamic normalization by the amplitude of the first harmonic of each sensor signal coming from a position sensor (20), this circuit providing as output the first, the second, and the third input signal of the circuit (102) for dynamic compensation of angular offset defect.

13. Set including: - a rotating electrical machine for the propulsion of a hybrid or electric vehicle, and - a control device for this electrical machine, comprising a determination device (100) according to any one of the preceding claims.

14. Method for determining the angular position of a rotor (4) of a rotating electrical machine on the basis of only three sensor signals provided by position sensors, in which a determination device (100) according to any one of claims 1 to 12 is used.

15. Computer program product comprising instructions which cause the assembly according to claim 13 to execute the steps of the method according to claim 14.

16. Computer-readable medium on which the computer program according to claim 15 is recorded.

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