FR3141520A1 - Device for determining the position and/or speed of a moving part of an electrical machine and associated method - Google Patents

Abstract

Title: Device for determining the position and/or speed of a moving part of an electrical machine and associated method The invention relates to devices and methods for determining the position and/or speed of a part mobile of an electric machine. To this end, it is proposed to: Modulate an electrical power supply signal of the electrical machine 2 by superimposing on it an electrical injection signal having a predetermined frequency at least five times higher, preferably at least ten times higher, than a fundamental frequency of the electrical supply signal of the electrical machine, Measure a vibro-acoustic response 100 of the electrical machine to the modulated electrical supply signal, and Process the vibro-acoustic response 100 measured by the acoustic sensor 12 to extract a signal therefrom electrical 101 representative of said at least one state variable. An alternative, or a complement, to existing control devices without sensors is thus offered and/or a solution that is both efficient and low-cost relative to existing control devices with mechanical sensor(s). Figure for abstract: Fig.1

Description

Device for determining the position and/or speed of a moving part of an electrical machine and associated method

The present invention relates to devices and methods for determining the position and/or speed of a moving part of an electrical machine. It relates more particularly to such devices and method for determining at least one state variable representative of the position and/or speed of a moving part of an electrical machine of an electrical system with closed control loop regulation . Such devices and processes can be applied in many fields, and in particular in transport (metro, trains, ship propulsion, electric automobiles), in industry (machine tools), and in household appliances.

STATE OF THE ART

There are several devices configured to determine the position and/or speed of a rotating movable part of an electrical machine. These existing devices can be classified into two categories: devices with mechanical sensor(s) with or without contact and sensorless devices which use the electrical signals generated by the electrical machine and extract position estimators and/or speed of the rotating mobile part. Sensorless devices are inexpensive, but developments remain desirable to make them more reliable or to provide more reliable alternatives. Among contact mechanical sensor devices, most involve the implementation of a resolver, code wheel or other contact transducers configured to transform a change in rotor angle into an electrical value. And among the devices with non-contact mechanical sensors, we can cite devices for determining the angular position of a rotor of electrical machines using magnetic targets to control the electrical machine via a control loop; such a device using Hall effect sensors more particularly is for example described in each of the patent applications referenced FR 3,115,362 A1 and EP 0,333,572 A1. The performance of mechanical sensor devices is generally satisfactory, but their cost is high.

The present invention aims to offer an alternative or complement to existing control devices without sensors and/or a solution that is both efficient and low cost relative to existing control devices with mechanical sensor(s).

SUMMARY

1. Un dispositif de modulation de signal électrique (ou modulateur) configuré pour moduler un signal électrique d’alimentation de la machine électrique en injectant un signal électrique dit d’injection en superposition du signal électrique d’alimentation de la machine électrique en fonctionnement, le signal électrique d’injection présentant une fréquence prédéterminée au moins cinq fois supérieure, de préférence au moins dix fois supérieure, à une fréquence fondamentale du signal électrique d’alimentation de la machine électrique,
2. Un capteur acoustique configuré pour mesurer une réponse vibro-acoustique de la machine électrique en fonctionnement, et
3. Un dispositif de traitement de la réponse vibro-acoustique mesurée par le capteur acoustique, le dispositif de traitement étant configuré pour extraire, de la réponse vibro-acoustique, un signal électrique représentatif de ladite au moins une variable d’état.

To achieve this objective, according to a first aspect of the invention, a system is provided for determining at least one state variable representative of the position and/or speed of a moving part of an electrical machine of an electrical system with closed control loop regulation, the determination system is essentially such that it includes:

1. An electrical signal modulation device (or modulator) configured to modulate an electrical power supply signal of the electrical machine by injecting a so-called injection electrical signal superimposed on the electrical power supply signal of the electrical machine in operation, the signal electric injection having a predetermined frequency at least five times higher, preferably at least ten times higher, than a fundamental frequency of the electrical power supply signal of the electrical machine,
2. An acoustic sensor configured to measure a vibro-acoustic response of the electrical machine in operation, and
3. A device for processing the vibro-acoustic response measured by the acoustic sensor, the processing device being configured to extract, from the vibro-acoustic response, an electrical signal representative of said at least one state variable.

1. une machine électrique présentant une partie mobile et
2. un système de détermination d’au moins une variable d’état représentative de la position et/ou de la vitesse de la partie mobile de la machine électrique tel qu’introduit ci-dessus.

According to a second aspect of the invention, an electromechanical system is provided with closed control loop regulation comprising:

1. an electric machine having a movable part and
2. a system for determining at least one state variable representative of the position and/or speed of the moving part of the electric machine as introduced above.

1. La modulation, par un dispositif de modulation de signal électrique (ou modulateur), d’un signal électrique d’alimentation de la machine électrique en injectant un signal électrique dit d’injection en superposition du signal électrique d’alimentation de la machine électrique en fonctionnement, le signal électrique d’injection présentant une fréquence prédéterminée au moins cinq fois supérieure à une fréquence fondamentale du signal électrique d’alimentation de la machine électrique,
2. La mesure, par un capteur acoustique, d’une réponse vibro-acoustique de la machine électrique, et
3. L’extraction, par un dispositif de traitement de la réponse vibro-acoustique mesurée par le capteur acoustique, d’un signal électrique représentatif de ladite au moins une variable d’état.

According to a third aspect of the invention, a method is provided for determining at least one state variable representative of the position and/or speed of a moving part of an electrical machine of an electrical system with closed control loop regulation, the process being essentially such that it comprises:

1. The modulation, by an electrical signal modulation device (or modulator), of an electrical signal supplying the electrical machine by injecting an electrical signal called injection superimposed on the electrical signal supplying the electrical machine in operation, the electrical injection signal having a predetermined frequency at least five times greater than a fundamental frequency of the electrical power supply signal of the electrical machine,
2. The measurement, by an acoustic sensor, of a vibro-acoustic response of the electrical machine, and
3. The extraction, by a device for processing the vibro-acoustic response measured by the acoustic sensor, of an electrical signal representative of said at least one state variable.

The vibro-acoustic response of the electrical machine is at least partly induced by the electrical injection signal.

The invention, according to its different aspects, responds to the need(s) to offer a more reliable alternative or a complement to existing sensorless control devices and/or a solution that is both efficient and low cost relative to existing control devices with mechanical sensor(s).

BRIEF DESCRIPTION OF THE FIGURES

The aims, objects, as well as the characteristics and advantages of the invention will emerge better from the detailed description of an embodiment of the latter which is illustrated by the following accompanying drawings in which:

There represents an electronic functional diagram of an electrical system equipped with a determination system according to one embodiment of the first aspect of the invention.

There represents an electronic functional diagram detailing a first part of the electronic functional diagram illustrated on the .

There represents an electronic functional diagram detailing a second part of the electronic functional diagram illustrated on the .

There represents different stages of an example of implementation of the processing carried out, on the vibro-acoustic response of the electric machine, by the processing device of a determination system according to an embodiment of the first aspect of the invention.

There represents a step of transmitting, to a phase-locked loop of the determination system according to one embodiment of the first aspect of the invention, an electrical signal representative of the position and/or speed of a moving part of the electric machine, to regulate the operation of the electric machine.

There graphically represents an example of vibro-acoustic response of an electrical machine as implemented by the inventors on a test bench of an embodiment of the determination system according to the first aspect of the invention.

There graphically represents the Fourier transform of the vibro-acoustic response illustrated on the .

There represents an enlargement on zone A surrounded by the which is located around the predetermined frequency of the injection signal used by the inventors.

The drawings are given as examples and are not limiting to the invention. They constitute schematic representations of principle intended to facilitate the understanding of the invention.

DETAILED DESCRIPTION

Before beginning a detailed review of embodiments of the invention, the following are set out as optional characteristics which may possibly be used in combination or alternatively:

According to one example, the determination system may further comprise a phase-locked loop arranged downstream of the processing device, and the processing device may further be configured to transmit the extracted electrical signal to the phase-locked loop, to regulate the operation of the electrical machine as a function of the extracted electrical signal.

According to one example, the phase-locked loop can be configured, together with the closed control loop of the electrical machine, to regulate the electrical current supplying the electrical machine as a function of the extracted electrical signal.

According to one example, the phase-locked loop can be configured to process the transmitted electrical signal so as to extract a first electrical signal representative of the estimated speed of the moving part of the electrical machine and a second electrical signal representative of the position estimated of the moving part of the electrical machine, and to transmit the first electrical signal and the second electrical signal to the closed control loop of the electrical system.

According to one example, the electrical injection signal may have a predetermined frequency at least five times higher, preferably at least ten times higher, than a maximum fundamental frequency of the electrical power supply signal of the electrical machine.

According to one example, the modulation device can be arranged upstream of a power stage of the electrical system configured to power the electrical machine.

According to one example, the determination system may further comprise an amplifier and an analog-digital converter arranged upstream of the processing device and configured to amplify and convert the vibro-acoustic response measured by the acoustic sensor.

1. un premier filtre passe-bande centré sur la fréquence du signal électrique d’injection pour filtrer la réponse vibro-acoustique mesurée par le capteur acoustique,
2. un multiplicateur configuré pour démoduler l’amplitude en quadrature du signal électrique filtré par le premier filtre passe-bande, et
3. un deuxième filtre passe-bande centré sur au moins un multiple de la fréquence du signal électrique d’alimentation de la machine électrique pour filtrer le signal électrique démodulé par le multiplicateur.

According to one example, the processing device may comprise at least:

1. a first band-pass filter centered on the frequency of the electrical injection signal to filter the vibro-acoustic response measured by the acoustic sensor,
2. a multiplier configured to demodulate the quadrature amplitude of the electrical signal filtered by the first bandpass filter, and
3. a second bandpass filter centered on at least a multiple of the frequency of the electrical power supply signal of the electrical machine to filter the electrical signal demodulated by the multiplier.

According to one example, the electric machine may comprise a synchronous machine with permanent magnets.

1. La transmission, par le dispositif de traitement, du signal électrique extrait à une boucle à verrouillage de phase agencée en aval du dispositif de traitement, pour réguler le fonctionnement de la machine électrique en fonction du signal électrique extrait.

According to one example, the determination method may further comprise:

1. The transmission, by the processing device, of the extracted electrical signal to a phase-locked loop arranged downstream of the processing device, to regulate the operation of the electrical machine as a function of the extracted electrical signal.

1. le traitement, par la boucle à verrouillage de phase, du signal électrique transmis de sorte à en extraire un premier signal électrique représentatif de la vitesse estimée de la pièce mobile de la machine électrique et un deuxième signal électrique représentatif de la position estimée de la pièce mobile de la machine électrique, et
2. la transmission, par la boucle à verrouillage de phase, des premier et deuxième signaux électriques à la boucle de contrôle fermée du système électrique.

According to an example, the determination method may include:

1. processing, by the phase-locked loop, the transmitted electrical signal so as to extract a first electrical signal representative of the estimated speed of the moving part of the electrical machine and a second electrical signal representative of the estimated position of the part mobile of the electric machine, and
2. transmitting, through the phase-locked loop, the first and second electrical signals to the closed control loop of the electrical system.

According to one example, the determination method can be such that the extraction of the electrical signal representative of said at least one state variable comprises a demodulation of the vibro-acoustic response measured by the acoustic sensor to obtain a demodulated electrical signal proportional to said at least one state variable.

According to one example, the determination method may further comprise the amplification and conversion, by an amplifier and an analog-digital converter arranged upstream of the processing device, of the vibro-acoustic response measured by the acoustic sensor.

1. Le filtrage, par un premier filtre passe-bande centré sur la fréquence du signal électrique d’injection, de la réponse vibro-acoustique,
2. La démodulation, par un multiplicateur, de l’amplitude en quadrature du signal électrique filtré par le premier filtre passe-bande, et
3. Le filtrage, par un deuxième filtre passe-bande centré sur au moins un multiple de la fréquence du signal électrique d’alimentation de la machine électrique, du signal électrique démodulé.

According to one example, the determination method can be such that the processing, by the processing device, of the vibro-acoustic response measured by the acoustic sensor comprises at least:

1. Filtering, by a first bandpass filter centered on the frequency of the electrical injection signal, of the vibro-acoustic response,
2. Demodulating, by a multiplier, the quadrature amplitude of the electrical signal filtered by the first bandpass filter, and
3. Filtering, by a second bandpass filter centered on at least a multiple of the frequency of the electrical power supply signal of the electrical machine, of the demodulated electrical signal.

1. une machine électrique 2 présentant une partie mobile 21, en rotation et/ou en translation, et
2. un système de détermination 1 d’au moins une variable d’état représentative de la position et/ou de la vitesse de la partie mobile 21 de la machine électrique 2 selon un autre aspect de l’invention.

In reference to the annexed, it is currently provided, according to one aspect of the present invention, an electromechanical system 0 with closed control loop regulation comprising at least:

1. an electric machine 2 having a movable part 21, in rotation and/or in translation, and
2. a system 1 for determining at least one state variable representative of the position and/or speed of the mobile part 21 of the electric machine 2 according to another aspect of the invention.

More particularly, is illustrated, on the , a known and commercially available electrical system 0' which is advantageously equipped with a determination system 1 according to the first aspect of the invention, to obtain an electromechanical system 0 according to the second aspect of the invention. Note here that the description of the determination method according to the third aspect of the invention follows immediately from the description given below of the first and second aspects of the invention.

1. une boucle de contrôle fermé 22 permettant de commander la machine électrique 2, par rétroaction, en fonction d’un signal de sortie de la machine électrique 2, et
2. un étage de puissance 23.

In known manner, the electrical system 0' can comprise, in addition to the electrical machine 2:

1. a closed control loop 22 making it possible to control the electric machine 2, by feedback, as a function of an output signal from the electric machine 2, and
2. a power stage 23.

More particularly, the closed control loop 22 makes it possible to control the power supply signal of the electrical machine 2, and even more particularly the input signal of the power stage 23, as a function of the output signal of the electrical machine 2. The different electronic components producing the closed control loop 22 and the power stage 23 are not further described here, being known and being able to take different shapes and arrangements, without limiting the ability of the person skilled in the art to adapt the determination system 1 according to the first aspect of the invention.

Furthermore, the electric machine 2 can be a synchronous or asynchronous machine. In particular, the electric machine 2 may be, or include, a synchronous machine with permanent magnets.

1. Un dispositif de modulation 11 de signal électrique configuré pour moduler un signal électrique d’alimentation de la machine électrique 2 en injectant un signal électrique dit d’injection en superposition du signal électrique d’alimentation de la machine électrique,
2. Un capteur acoustique 12 configuré pour mesurer une réponse vibro-acoustique 100 (Cf. ) de la machine électrique 2 au signal électrique d’alimentation modulé, et
3. Un dispositif de traitement 13 de la réponse vibro-acoustique 100 mesurée par le capteur acoustique 12.

Still with reference to the , the determination system 1 according to the first aspect of the invention comprises at least:

1. An electrical signal modulation device 11 configured to modulate an electrical power supply signal of the electrical machine 2 by injecting a so-called injection electrical signal superimposed on the electrical power signal of the electrical machine,
2. An acoustic sensor 12 configured to measure a vibro-acoustic response 100 (Cf. ) from the electric machine 2 to the modulated electrical supply signal, and
3. A device 13 for processing the vibro-acoustic response 100 measured by the acoustic sensor 12.

The electrical injection signal has a frequency predetermined at least five times higher, preferably at least ten times higher, or even at least fifty times higher, at a fundamental frequency of the electrical supply signal of the electrical machine 2. In known manner, this fundamental frequency evolves as a function of the operating speed of the electrical machine 2. For example, the fundamental frequency of the electrical power supply signal of the electrical machine 2 can vary between 0 and 500 Hz, most often between 0 and 150 Hz; when it is zero, the electric machine 2 is stopped and, when it is greater than zero, the electric machine 2 is considered to be in operation, although the machine may not rotate for very low frequencies due to of the load that the machine has to support.

This evolution of the fundamental frequency of the electrical supply signal of the electrical machine 2 is, in a known manner, bounded above, so that it is possible to define a maximum fundamental frequency of the electrical signal supplying the electrical machine. Preferably, the frequency of the electrical injection signal will be predetermined as being at least five times greater, preferably at least ten times greater, or even at least fifty times greater, than the maximum fundamental frequency of the electrical signal supplying the electrical machine.

Note, moreover, that the frequency of the electrical injection signal is also limited above, in particular in proportion to the maximum switching frequency of the electronic switches of the inverter 231 of the power stage 23 of the electrical system 0'; the maximum switching frequency of such switches is between 5 and 20 kHz depending on the machine used, and is typically substantially equal to 10 kHz.

Note also that, if the electrical injection signal preferably takes a sinusoidal shape, it can also take a rectangular, triangular, or even sawtooth shape.

Note further that, if the frequency of the electrical injection signal can vary, for example to follow the evolution of the frequency of the electrical supply signal, it is preferable that the frequency of the electrical injection signal is predetermined constant; this preference greatly simplifies the processing, described below, of the vibro-acoustic response 100 measured by the acoustic sensor 12. Depending on the machine used, the frequency of the electrical injection signal is preferably comprised, or chosen constant, between 500 Hz and 5 kHz, even more preferably comprised between 1 and 3 kHz, and for example substantially equal to 2 kHz.

The modulation device 11 is not necessarily of the ‘software’ type. In this sense, the modulation device 11 is not necessarily digital, but can on the contrary be purely analog. It can be envisaged that the function of the modulation device 11 is implemented by modifying an electronic variator of the electrical system 0', and more particularly by modifying the way in which this variator is programmed, for example by updating the software of the variator. Alternatively, it can be envisaged that the function of the modulation device 11 is implemented by adding an analog box containing the electronics necessary to carry out the modulation.

It appears from the above that the modulation device 11 can be arranged upstream of the power stage 23, or even upstream of the inverter 231, of the electrical system 0'. The power stage 23 of the electrical system 0' is therefore potentially, and even preferentially, not modified by the addition of the determination system 1 to the electrical system 0'.

The modulation device 11 can more particularly be configured to act on each of the direct voltage and the quadrature voltage injected at the input of the power stage 23 of the electrical system 0', by respectively superimposing a direct injection voltage on them and an injection quadrature voltage , as shown in the .

The acoustic sensor 12 can be a simple microphone, or even an electret. As an alternative to phonic technology, vibration technology can also be used; and the bandwidth of the acoustic sensor 12 is potentially affected by the phonic or vibration technology chosen. The acoustic sensor 12 preferably has a bandwidth comprising at least the frequency of the electrical injection signal and at least part of the harmonic content of this signal.

Such an acoustic sensor 12 being very inexpensive, its use justifies at least in part that the proposed solution is a low-cost solution, particularly in relation to existing solutions with mechanical sensors with or without contact.

It is possible that such a low-cost acoustic sensor 12 does not allow a measurement of sufficient amplitude to be processed directly in a fully satisfactory manner. To respond to this possible difficulty, and as illustrated on the , an amplifier and an analog-digital converter (or ADC) 15 can be added upstream of the processing device 13, so as to amplify and convert the vibro-acoustic response 13 measured by the acoustic sensor 12. More particularly, the voltage of output of the acoustic sensor 12 can be between ±20 mV and the voltage admissible by the microcontroller constituting the processing device 13 can be between 0 and 3.3 V.

The acoustic sensor 12 is preferably arranged so as to 'listen' to the electrical machine 2. To this end, it can of course be arranged close to the electrical machine 2, as is illustrated in the figure. .

The processing device 13 is, for its part, configured to extract, from the vibro-acoustic response 100, possibly amplified, an electrical signal 101 representative of the state variable to be determined. Therefore, the electrical signal 101 constitutes a first level of determination of the state variable or variables that the system 1 according to the first aspect of the invention aims to determine.

The processing device 13 is not necessarily of the ‘software’ type. In this sense, the processing device 13 is not necessarily digital, but can on the contrary be purely analog. It can be envisaged that the function of the processing device 13 is implemented by modifying an electronic variator of the electrical system 0', and more particularly by modifying the way in which this variator is programmed, for example by updating the software of the variator. Alternatively, it can be envisaged that the function of the processing device 13 is implemented by adding an analog box containing the electronics necessary to carry out the processing.

Note here that the determination system 1 according to the first aspect of the invention is advantageously not specific to a determined mobility of the moving part 21, nor moreover to the number of moving parts that the electrical machine 2 can include. On the contrary, certain existing solutions are designed to determine a mechanical state variable of a moving part moving only in rotation or moving only in translation. The determination system 1 according to the first aspect of the invention does not present this limit, and concerns both rotating machines, such as motors and alternators, and electromechanical devices having a moving part, such as contactors. , linear motors, etc., which modifies its acoustic response.

In view of the above, it appears that the present invention aims to exploit the idea that the mechanical vibrations of an electrical machine 2, or even of an electrical system 0', in operation create a sound, called here vibro-response. acoustic 100, which can carry information that can be used to determine a mechanical state variable of the electrical machine 2, and by extension of the electrical system 0'.

More particularly, when the electric machine 2, or typically the stator of a synchronous machine, is traversed by an alternating current, the electromagnetic forces associated with these currents compress and expand the electric machine 2, and more particularly its stator, causing radial movements and thus generating a sound wave. In normal operation, an electrical machine 2, typically a synchronous machine, therefore emits noise from several sources: noise linked to mechanical friction, noise from the bearings, noise linked to the air stirred by the stator and noise linked to to the magneto-mechanical coupling of the machine. Only the latter is directly linked to stator currents. Thus, by injecting currents with an identified frequency signature, by superimposing them on the conventional control currents of the machine, a sound containing a comparable frequency signature can be recovered by an acoustic sensor 12 arranged to listen to the machine.

In order to exploit this acoustic phenomenon, the inventors propose to inject, superimposed on the electrical power supply signal of the electrical machine 2, an electrical injection signal having a high frequency, relative to the frequency of the electrical power signal , so that the high-frequency currents injected into the stator of the electrical machine 2, by coupled effect, induce a vibration of the stator and therefore the corresponding production of a sound. This therefore causes a modification of the vibro-acoustic response of the electrical machine 2, without however influencing, at least significantly, the operation of the electrical machine 2.

Note here that, below a certain amplitude, the electrical injection signal has no influence on the operation of machine 2 and its frequency is too high to interact with the regulators of the main control loop. On the other hand, too low an amplitude of the injection signal could not make it possible to generate an acoustic response strong enough to be detected by the acoustic sensor 12. Typically, the amplitude of the injected signal will preferably be chosen between 5% and 10 % of supply voltage.

In this way, the electric machine 2 vibrates and produces a vibro-acoustic response, in particular around the frequency of the electrical injection signal and around its harmonics.

As already mentioned above, the illustrates an example of recording by an acoustic sensor 12 of the vibro-acoustic response 100 of an electric machine 2 implemented in accordance with the determination method according to the third aspect of the invention. This electrical test machine here consists of a synchronous machine with permanent magnets, and more particularly such a machine with smooth poles dimensioned for 48 V and 1.6 kW. The test bench on which this machine is mounted thus presents classic characteristics of an electric conversion chain for a hybrid vehicle.

In the test carried out from which the attached Figures 6 to 8 are taken, the synchronous machine with permanent magnets 2 is powered by an electrical supply signal having a fundamental frequency substantially equal to 25 Hz, to which has been superimposed an electrical injection signal having a frequency substantially equal to 1440 Hz. Under these power conditions, the rotor of the permanent magnet synchronous machine rotates at a speed substantially equal to 500 rpm.

In Figure 7, the Fourier transform 100' of the acoustic recording 100 illustrated in Figure 6 is illustrated. An enlargement of Figure 7, which is centered on the frequency of the electrical injection signal, is illustrated in Figure 8. We observe a peak 1000 at the frequency of the electrical injection signal, a peak 1001 at the frequency , and a peak 1002 at the frequency .

It is thus demonstrated that the electric injection current actually has, on the vibro-acoustic response of the electric machine 2, an influence at least at the level of characteristic frequency lines, and in particular around the frequency of the electrical injection signal and some of its harmonics. The analysis of the Fourier transform of the vibro-acoustic response 100 therefore shows that, around the frequency of the electrical injection signal, the main peaks observed correspond to the frequency of the injected current plus and minus the rotation frequency of the rotor of machine 2.

Subsequently, it is shown how the processing of the vibro-acoustic response 100 by the processing device 13 makes it possible to determine a state variable representative of the speed and the angle of the rotor, and to then use this variable. status to control the machine, in particular to eliminate the need for a position sensor that is often expensive and bulky.

It is first demonstrated analytically that it is possible to deduce, from the observed influence of an electric injection current on the vibro-acoustic response of the machine 2, information useful for determining at least one state variable representative of the position and/or speed of the mobile part 21 of the electrical machine 2. It is then shown how such a state variable can be transmitted to the closed control loop so as to be used by the latter, in a known manner, to regulate the operation of machine 2.

The modulated electrical supply signal can be modeled, particularly in the case of a synchronous machine with permanent magnets, using a so-called model. taking the following form:

Or is the stator resistance, is the inductance of the stator windings in the stator two-phase frame of reference , is the magnetic flux generated by the rotor magnets and And are respectively the rotation speed and the electrical position of the machine.

Furthermore, the electrical injection signal can be modeled in the form of the following formula defining the injected voltage:

Or is the voltage of the injection signal in the dq frame of reference of the machine, is the amplitude of the injection voltage and is the pulsation of the injection signal.

Therefore, the stator currents obtained in the permanent magnet synchronous machine can be modeled by the following formula:

Or And are respectively the values of the stator inductances of the machine in the rotating two-phase reference frame dq , And .

We thus see analytically that the stator currents include at least one component at the frequency and at least one component at the frequency . We therefore find here the influence announced above of these components on the vibro-acoustic response 100 of the permanent magnet synchronous machine. More particularly, it is thus demonstrated that, when a current of frequency much higher than the frequency of the supply current of the electric machine 2 is injected into the rotor frame of the rotating machine, the currents which result in the three-phase stator frame of the machine have fundamental frequencies And .

The noise then emitted by the machine is therefore composed, in the frequency domain, of compositions of these two frequencies And . By knowing the frequency of the electrical injection signal, since it is the one that is injected, it is possible by processing the sound signal with a series of judiciously chosen filters to extract a frequency signal representative of the rotation frequency of the rotor. Thus, the acoustic signal 100 of a machine 2 subjected to the injection of an electrical signal of frequency includes at least one frequency component and at least one frequency component , where k belongs to the set {0, 2, 4, 6, 8, …}.

The constant k which corresponds to the frequency component whose amplitude is dominant compared to the others, depends strongly on the machine 2 and can be determined by a preliminary analysis of the acoustic response of the machine 2 to an electrical injection signal such as that presented in figures 6, 7 and 8.

It emerges from the preceding analytical demonstration that adequate processing of the vibro-acoustic response 100 of machine 2 must make it possible to determine a state variable representative of the estimated position of the moving part 21 of the electric machine 2, by recovering the angle of the rotor of the machine relative to the stator, and a state variable representative of the rotation speed of the rotor of the machine, by integration of the determined evolution of the rotor angle.

The processing of the vibro-acoustic response 100 of the electrical machine 2 is carried out by the processing device 13 as introduced above and is more particularly illustrated in the attached Figures 2 and 4.

Note that the considerations below made with reference to Figures 2 and 4 no longer specifically concern the aforementioned test, and in particular are not necessarily limited to the implementation of a synchronous machine with permanent magnets.

1. un premier filtre passe-bande 131,
2. un multiplicateur 132, et
3. un deuxième filtre passe-bande 133.

As illustrated on the , the processing device 13 comprises at least:

1. a first bandpass filter 131,
2. a multiplier 132, and
3. a second bandpass filter 133.

The first bandpass filter 131 is centered on the frequency of the electrical injection signal. As illustrated on the , it receives, as input, the vibro-acoustic response 100, measured by the acoustic sensor 12, and if necessary amplified. It outputs a filtered signal as illustrated in the “stage II” box of the .

The multiplier 132 is configured to demodulate the quadrature amplitude of the electrical signal filtered by the first bandpass filter 131. It receives, as input, the electrical signal filtered by the first bandpass filter 131 and a complex demodulation vector composed sinuses and cosines of the electrical injection signal, so as to be able to multiply the first by the second. In response to its inputs, the multiplier 132 emits a so-called orthogonalized signal, as illustrated in the “stage III” box of the , towards the second bandpass filter 133.

The second bandpass filter 133 is centered on at least one multiple of frequency of the electrical power supply signal of the electrical machine 2 to filter the electrical signal demodulated by the multiplier 132. We thus obtain a complex frequency modulated signal 101, as illustrated in the “stage IV” box of Figure 4, composed of two functions: And , Or corresponds to the electrical pulsation linked to the rotor speed of the machine. In other words, these are two orthogonal frequency signals which are obtained at the output of the second bandpass filter 133.

The complex frequency modulated signal 101 has the value of a first level for determining a state variable representative of the position and/or speed of the mobile part 21 of the electrical machine 2, at least in the sense that it intrinsically carries the information representative of the position and speed of the mobile part 21 of the electric machine 2, as emerges from what follows.

A second level of determination, more advanced than the first, of the state variable representing the position and/or speed of the mobile part 21 of the electrical machine 2 is reached, when the determination system 1 further comprises a phase-locked loop 14 arranged downstream of the processing device 13 and upstream of the closed control loop of the electrical system 0 '.

More particularly, the phase-locked loop 14 can be as illustrated in the diagram of the annexed. Such a phase-locked loop 14 is known and commercially available; it is therefore not more detailed here than allowed by the . It can be called heterodyne in this sense the signal processing it implements is based on the multiplication of several frequencies.

The processing device 13 can then be further configured to transmit the electrical signal 101 to the phase-locked loop 14, to regulate the operation of the electrical machine 2 as a function of this signal.

Note that the determination system 1 then constitutes a system for controlling the operation of the electrical machine 2, in particular when considered jointly with the closed control loop 22 of the electrical system 0'. In fact, the phase-locked loop 14 can therefore be configured, together with the closed control loop of the electrical machine, to regulate the electrical current supplying the electrical machine 2 as a function of the electrical signal 101.

More particularly, and with reference to Figures 3 and 5, the phase-locked loop 14 can be configured to process the electrical signal 101 transmitted to it so as to extract a first electrical signal 102 representative of the speed estimate of the moving part 21 of the electrical machine 2 and a second electrical signal 103 representative of the position estimated value of the moving part 21 of the electrical machine 2, as well as to transmit the first electrical signal 102 and the second electrical signal 103 to the closed control loop of the electrical system 0'.

As illustrated in Figure 5, and as already mentioned above, the complex frequency modulated signal 101 can be transmitted to the phase-locked loop 14 for further processing, and more particularly to extract the state variables therefrom. such as usually used, in feedback, by the closed control loop of the electrical system 0', in particular for the famous Park-Concordia transformation. As mentioned above, we obtain, at the output of the phase-locked loop 14, an estimated angle , also known as electric angle, and an estimated speed of the rotor of the permanent magnet synchronous machine.

Note here that the phase-locked loop 14 is not more detailed here than it is in Figures 3 and 5, in particular due to the fact that the phase-locked loop 14 implemented here is not distinguished in none of those known to those skilled in the art.

The test bench created by the inventors made it possible to carry out steady state tests which showed good performance over a wide range of rotational speeds of the machine rotor, and more particularly between 0 and 1000 rpm. Start-up and load step tests have also been carried out which are also satisfactory, proving that the control of the machine by implementing the present invention is robust relative to disturbances and at low speed, unlike existing control techniques without sensor.

Note here that the acoustic sensor 12 may not only capture the sound produced by the mobile part 21 of the electrical machine 2 whose position and/or speed it is desired to determine, but may also capture other sounds produced by the electrical machine 2, by the electrical system 0', as well as sounds present in the environment of the electromechanical system 0. The arrangement of the acoustic sensor 12 is preferably such that it makes it possible to minimize the capture of sounds not produced by the part mobile 21 of the electric machine 2. In addition or as an alternative, the bandwidth of the acoustic sensor 12 can be adjusted to avoid overlap with certain ambient sounds or with the bandwidth of another acoustic sensor. However, the fact that sounds qualifying as parasites are still picked up by the acoustic sensor 12 does not render the invention inoperative according to its different aspects. It is also envisaged that the same acoustic sensor 12 is used to determine the state variables of a plurality of electrical machines 'listened to' by this sensor.

The invention according to its different aspects is intended to be an alternative or a complement to the position and/or speed sensors of a moving engine part in the automobile field and a complement to the position and/or speed sensors of a moving engine part. 'a moving engine part in the field of aeronautics.

The invention according to its different aspects makes it possible to increase the reliability of electrical systems 0' by offering measurement redundancy with respect to controls based on noise, vibrations and harshness (or NVH for "Noise, Vibrations and Harshness" according to Anglo-Saxon terminology).

Beyond the cost reduction already mentioned above, the invention according to its different aspects can claim to be less heavy and more durable than some of the existing solutions, which makes the integration of the invention particularly advantageous in on-board systems. .

The invention is not limited to the embodiments previously described and extends to all the embodiments covered by the invention.

Claims (14)

System for determining (1) at least one state variable representative of the position and/or speed of a moving part (21) of an electrical machine (2) of an electrical system (0') with closed control loop regulation, the determination system (1) being characterized in that it comprises:

• An electrical signal modulation device (11) configured to modulate an electrical power supply signal of the electrical machine (2) by injecting a so-called injection electrical signal superimposed on the electrical power supply signal of the electrical machine, the signal electric injection having a predetermined frequency at least five times higher, preferably at least ten times higher, than a fundamental frequency of the electrical power supply signal of the electrical machine,
• An acoustic sensor (12) configured to measure a vibro-acoustic response (100) of the electrical machine (2) to the modulated electrical power signal, and
• A device (13) for processing the vibro-acoustic response (100) measured by the acoustic sensor (12), the processing device (13) being configured to extract, from the vibro-acoustic response (100), an electrical signal (101) representative of said at least one state variable.

Determination system (1) according to the preceding claim, further comprising a phase-locked loop (14) arranged downstream of the processing device (13), and wherein the processing device (11) is further configured to transmit the electrical signal (101) extracted to the phase-locked loop (14), to regulate the operation of the electrical machine (2) according to the electrical signal (101) extracted. Determination system (1) according to the preceding claim, in which the phase-locked loop (14) is configured to process the electrical signal (101) transmitted so as to extract a first electrical signal (102) representative of the estimated speed of the moving part (21) of the electrical machine (2) and a second electrical signal (103) representative of the estimated position of the moving part (21) of the electrical machine (2), and to transmit the first electrical signal ( 102) and the second electrical signal (103) to the closed control loop of the electrical system (0'). Determination system (1) according to any one of the preceding claims, in which the electrical injection signal has a predetermined frequency at least five times higher, preferably at least ten times higher, than a maximum fundamental frequency of the electrical signal d power supply to the electric machine (2). Determination system (1) according to any one of the preceding claims, in which the modulation device (11) is arranged upstream of a power stage (23) of the electrical system (0') configured to power the electrical machine (2). Determination system (1) according to any one of the preceding claims, further comprising an amplifier and an analog-digital converter (15) arranged upstream of the processing device (13) and configured to amplify and convert the vibro-acoustic response (100) measured by the acoustic sensor (12). Determination system (1) according to any one of the preceding claims, in which the processing device (13) comprises at least:

• a first bandpass filter (131) centered on the frequency of the electrical injection signal to filter the vibro-acoustic response (100) measured by the acoustic sensor (12),
• a multiplier (132) configured to demodulate the quadrature amplitude of the electrical signal filtered by the first bandpass filter (131), and
• a second bandpass filter (133) centered on at least a multiple of the frequency of the electrical power supply signal of the electrical machine (2) to filter the electrical signal demodulated by the multiplier (132).

Electromechanical system (0) with closed control loop regulation comprising at least:

• an electric machine (2) having a movable part (21), and
• a system for determining (1) at least one state variable representative of the position and/or the speed of the moving part (21) of the electric machine (2) according to any one of the preceding claims.

Electromechanical system (0) according to the preceding claim, in which the electric machine (2) comprises a synchronous machine with permanent magnets. Method for determining at least one state variable representative of the position and/or speed of a moving part (21) of an electrical machine (2) of an electrical system (0') with regulation in closed control loop, the method being characterized in that it comprises:

• The modulation, by an electrical signal modulation device (11), of an electrical power supply signal of the electrical machine (2) by injecting a so-called injection electrical signal superimposed on the electrical power signal of the machine electrical, the electrical injection signal having a predetermined frequency at least five times higher, preferably at least ten times higher, than a fundamental frequency of the electrical power supply signal of the electrical machine,
• Measuring, by an acoustic sensor (12), a vibro-acoustic response (100) of the electrical machine (2) to the modulated electrical supply signal, and
• Processing, by a processing device (13), of the vibro-acoustic response (100) measured by the acoustic sensor (12) to extract an electrical signal (101) representative of said at least one state variable.

Method according to the preceding claim, further comprising:

• Transmission, by the processing device (13), of the extracted electrical signal (101) to a phase-locked loop (14) arranged downstream of the processing device (13), to regulate the operation of the electrical machine (2 ) as a function of the electrical signal (101) extracted.

Method according to the preceding claim, comprising:

• processing, by the phase-locked loop (14), the electrical signal (101) transmitted so as to extract therefrom a first electrical signal (102) representative of the estimated speed of the moving part (21) of the electrical machine ( 2) and a second electrical signal (103) representative of the estimated position of the moving part (21) of the electric machine (2), and
• transmitting, through the phase-locked loop (14), the first and second electrical signals (102 and 103) to the closed control loop of the electrical system (0').

Method according to any one of the three preceding claims, further comprising the amplification and conversion, by an amplifier and an analog-digital converter (15) arranged upstream of the processing device (13), of the vibro-acoustic response (100) measured by the acoustic sensor (12). Method according to any one of the four preceding claims, in which the processing, by the processing device (13), of the vibro-acoustic response (100) measured by the acoustic sensor (12) comprises at least:

• Filtering, by a first band-pass filter (131) centered on the frequency of the electrical injection signal, the vibro-acoustic response (100),
• Demodulating, by a multiplier (132), the quadrature amplitude of the electrical signal filtered by the first bandpass filter (131), and
• Filtering, by a second band-pass filter (133) centered on at least a multiple of the frequency of the electrical signal supplying the electrical machine (2), of the demodulated electrical signal.