Method of controlling a rotating electrical machine

Abstract

Title: Method for controlling a rotating electrical machine The invention relates to a method for controlling a rotating electrical machine comprising phases by a control unit, the control method comprising a step of acting on the odd harmonics of order 3 and higher of the phase currents. Figure for the abstract: Fig. 2

Description

Title of the invention: Method for controlling a rotating electrical machine

[0001] The present invention relates to a method of controlling a rotating electrical machine.

[0002] The electrical machine is for example 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.

[0003] 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 the present 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.

[0004] 48V or high voltage electrical machines are a source of excitation in vibration and magnetic noise for the complete system including the machine, an inverter and a differential.

[0005] Indeed, in the case of a vehicle, the electrical machine is often connected via a shaft with splines or pinions to the differential. Magnetic noise is transmitted in solid by the structure of the bearings to the inverter and the differential, causing the mechanical parts to vibrate.

[0006] The reduction of these magnetic noises is a particularly important point in the context of an electric vehicle, and differentiates the solutions of the suppliers.

[0007] The invention relates to a method for controlling a rotating electrical machine comprising phases by a control unit, the control method comprising a step of acting on the odd harmonics of order 3 and higher of the phase currents.

[0008] According to one aspect of the invention, the rotating electrical machine is three-phase, or double three-phase.

[0009] According to one aspect of the invention, the method for controlling the rotating electrical machine comprises a step of selecting a set E of orders of odd harmonics of order greater than or equal to 3 on which the step of acting on the harmonics of order 3 and higher of the phase currents acts.

[0010] According to one aspect of the invention, the set E is for example the set

[0011] E={5;7]

[0012] According to one aspect of the invention, the step of action on the harmonics of order 3 and higher of the phase currents is therefore a step of action on the harmonics of order i, with ie E.

[0013] According to one aspect of the invention, the step of acting on the odd harmonics of orders 3 and higher can act with a different weighting on the different harmonics. In particular, the step of acting on the harmonics can act differently on the harmonics of orders 5 and 7.

[0014] According to one aspect of the invention, a step of action on the harmonics of order i, with ie E, consists of attenuating these harmonics.

[0015] According to one aspect of the invention, the reduction of odd harmonics of order 3 and higher, in particular of order 5 and 7, of the phase current makes it possible to reduce magnetic noise and to increase the performance of the machine.

[0016] According to one aspect of the invention, the reduction of odd harmonics of order 3 and higher, in particular of order 5 and 7, of the phase current also makes it possible to reduce magnetic noise coming from the rotating electrical machine.

[0017] Indeed, the control of the phases of a rotating electrical machine by sinusoidal control voltages produces in the electrical machine non-sinusoidal phase currents, in particular phase currents comprising harmonics of frequencies n times higher than the frequency of the control signal of the machine, with odd n greater than or equal to 3, in particular with n = 5 or n = 7. This is due to the imperfections of the real electrical machine.

[0018] According to one aspect of the invention, the step of action on the harmonics of order i, with

[0019] ie E of the phase currents consists of adapting the control voltages of the electrical machine.

[0020] In particular, the step of acting on the harmonics of order i, with ie E, of the phase current consists of modifying the sinusoidal control voltage of the rotating electrical machine into a non-sinusoidal control voltage, in particular into a control voltage comprising components at the frequencies of the harmonics of order i, with ie E.

[0021] According to one aspect of the invention, the addition to the control voltage of harmonics of order i, with ie E, makes it possible to attenuate, or even eliminate, the harmonics of order i, with ie E, in the phase currents of the rotating electrical machine, and therefore makes it possible to reduce the magnetic noise.

[0022] According to one aspect of the invention, the method for controlling a rotating electrical machine comprises a step of determining the odd harmonics of order 3 or higher, in particular of order 5 and 7, of the phase currents of the rotating electrical machine under given conditions of use of the machine.

[0023] In the following, we will use “determination step” for “the determination step”. components at the frequencies of odd order harmonics greater than 3, in particular 5 and 7 of the phase currents under given conditions of use of the machine”.

[0024] According to one aspect of the invention, the harmonics of order i, with ie E, are added to the control signal in phase opposition with harmonics obtained during the determination step, and with an amplitude defined to cancel or reduce these harmonics.

[0025] According to one aspect of the invention, the step of determining the odd harmonics of orders 3 and higher, in particular orders 5 and 7 of the phase currents is done online, namely during operation of the machine. This is then referred to as closed-loop control.

[0026] According to one aspect of the invention, the determination step comprises a step of acquiring the phase currents by sensors. These phase currents acquired by the sensors are sent to the input of a control unit.

[0027] According to one aspect of the invention, the method of controlling the rotating electrical machine by the control unit comprises a step of Clarke transformation of the phase currents acquired by the sensors.

[0028] The Clarke transformation is a projection of the quantities relative to the three phases onto two fixed axes (a, |3).

[0029] According to one aspect of the invention, in the case of a three-phase dual machine, two separate Clarke transformations are carried out for the phase currents Iq>123 and Iq>456 of the two groups of three phases. Two current vectors Ia[31 and Ia[32 are therefore obtained.

[0030] According to one aspect of the invention, the method for controlling the rotating electrical machine comprises a step of controlling the torque of the rotating machine, consisting of a step of acting on the fundamental of the phase current.

[0031] The vector used for the action on the fundamental of the phase current is then the average of the two current vectors Ia[31 and Ia[32, i.e.:

[0032] Ia|3f = O.5*(Ia|31 + Ia[32)

[0033] According to one aspect of the invention, this operation of summing the two current vectors makes it possible to obtain a signal Ia[3f independent of odd harmonics greater than 3, in particular harmonics 5 and 7.

[0034] According to one aspect of the invention, in the case of a three-phase system, the currents of the three phases Iq>123 are thus projected into the frame (a, |3), and the two-dimensional vector Ia[3 is obtained.

[0035] According to one aspect of the invention, the vector Ia[3 is filtered in order to obtain a vector used for the action on the fundamental of the phase current Ia[3f independent of odd harmonics greater than 3.

[0036] According to one aspect of the invention, the step of acting on the fundamental of the current of phase then includes a rotation of the axes which converts the alternating components of the frame (a, |3) into continuous components along a direct axis and a quadrature axis (frame (d, q)) with respect to the magnetic flux produced by the rotor. We then obtain a current vector Idqf in the base (d, q).

[0037] The combination of the Clarke transformation with the rotation from the (a, |3) frame to the (d, q) frame is known as the Park transformation. The main advantage of these transformations is a decoupling of the control.

[0038] According to one aspect of the invention, the step of acting on the fundamental of the phase current comprises a step of controlling the fundamental of the phase current, taking as input the current vector Idqf in the base (d, q), and returning as output a control voltage of the fundamental VBFdqf in the base (d, q).

[0039] According to one aspect of the invention, the step of acting on the fundamental of the phase current comprises an inverse Park transformation, i.e. an inverse rotation, followed by two inverse Clarke transformations, making it possible to obtain two control voltages of the fundamental of the phases Vq>123f and Vq>456f.

[0040] According to one aspect of the invention, the control voltages of the fundamental of the phases Vq>123f and Vq>456f are sinusoidal.

[0041] According to one aspect of the invention, the step of acting on the odd harmonics of orders 3 or higher, in particular of orders 5 and 7, comprises a step of transforming the phase currents acquired by the sensors making it possible to obtain an input vector independent of the fundamental of the phase currents.

[0042] According to one aspect of the invention, in the case of a three-phase double machine, the vector used for the action on the harmonics of the phase current is half the difference of the two current vectors Ia[31 and Ia[32, i.e.:

[0043] Ia|3h = O.5*(Ia|31 - Ia[32)

[0044] According to one aspect of the invention, the current vector Ia[3h, expressed in the frame (a, |3), is independent of the fundamental of the phase currents, and involves harmonics of order greater than or equal to 3 of the phase currents.

[0045] According to one aspect of the invention, the step of action on the harmonics of order i, with ie E comprises a separate step of action on each of the harmonics on which the step of action on the harmonics of order i acts.

[0046] For example, if the set E is the set E = {5;7], then the method for controlling the rotating electrical machine comprises a step of action on the 5th order harmonic of the phase current, and a separate step of action on the 7th order harmonic of the phase current.

[0047] According to one aspect of the invention, the step of acting on the harmonic of order i of the phase current, with ie E, comprises a step of rotating the axes which converts the alternating components of the reference frame (a, |3) into continuous components along a direct axis and an axis in quadrature (reference (d, q)) with respect to the magnetic flux produced by the rotor. We then obtain a current vector Idqi in the base (d, q).

[0048] According to one aspect of the invention, the frequency of the harmonic of order i of the phase currents is i times higher than the frequency of the fundamental of the phase currents. Thus, if the rotation for converting the components of the fundamental Ia[3f expressed in the frame (a, |3) into the frame (d, q) is a rotation of angle 0, then the step of acting on the harmonic of order i of the phase current comprises a rotation of angle i0.

[0049] According to one aspect of the invention, in the case of a three-phase machine, the step of acting on the harmonic of order i of the phase current, with ie E, comprises a step of rotation of angle i0 of the axes which converts the alternating components of the reference frame (a, |3) into continuous components along a direct axis and an axis in quadrature (reference frame (d, q)) with respect to the magnetic flux produced by the rotor. An unfiltered current vector Idqi_nf is then obtained in the base (d, q). This current vector is said to be “unfiltered” because it is dependent on the fundamental of the phase currents, and on the harmonics of orders different from i.

[0050] According to one aspect of the invention, the step of acting on the harmonic of rank i of the phase currents comprises a step of filtering the current vector Idqi_nf, making it possible to obtain a current vector Idqi depending only on the harmonic of rank i of the phase current.

[0051] According to one aspect of the invention, the step of acting on the harmonic of order i of the phase currents comprises a step of controlling the harmonic of rank i of the phase currents, taking as input the current vector Idqi in the base (d, q), and returning as output a control voltage of the harmonic of rank i VBFdqf in the base (d, q).

[0052] According to one aspect of the invention, the step of controlling the harmonic of rank i of the phase current generates a control voltage of the harmonic of rank i VBFdqf making it possible to bring these components back to a predetermined setpoint, for example zero.

[0053] According to one aspect of the invention, the use of a closed-loop control for the control of a harmonic is only possible for a rotation speed of the rotating electrical machine lower than a limit rotation speed Nmax dependent on the rank of the controlled harmonic, the number of pairs of poles of the rotating machine, the sampling frequency and the number of sampling points per harmonic.

[0054] According to one aspect of the invention, the limit rotation speed Nmax_i is expressed:

[0055] v _ Eduni

[0056] With fEchant the sampling frequency of the sensors, Npts the number of samples for the harmonic, i the rank of the harmonic and Npp the number of pairs of poles of the rotating machine.

[0057] According to another aspect of the invention, the step of determining the components at the frequencies of the odd harmonics of order 3 or higher of the phase currents comprises a step of characterizing the rotating machine carried out offline, namely upstream of the use of the machine. This is then referred to as open loop control.

[0058] According to one aspect of the invention, the step of characterizing the rotating machine comprises the choice of N characteristics of the rotating electrical machine, these N characteristics being able to influence the harmonics of the phase currents, and being measured, estimated, or acquired during the operation of the rotating machine.

[0059] According to one aspect of the invention, these characteristics can be chosen from: the rotation speed of the machine, one or more temperatures of the machine (at the level of the winding, the inverter, the cooling fluid),...

[0060] According to one aspect of the invention, the control voltages of the rotating machine are also dependent on the torque setpoint, i.e. the control setpoint of the fundamental of the phase current.

[0061] According to one aspect of the invention, the control voltages of the rotating machine are dependent on the rotation speed of the rotating machine.

[0062] According to one aspect of the invention, the step of characterizing the rotating machine for open-loop control comprises a mapping step.

[0063] According to one aspect of the invention, the mapping step comprises a calibration step consisting of a step of putting the machine into operation in a set of predetermined operating situations, each operating situation being defined by a torque setpoint, and by a combination of values ​​of each of the N characteristics of the rotating electrical machine chosen.

[0064] According to one aspect of the invention, the mapping step comprises, for each operation in an operating situation, a measurement of the harmonics of order i, with ie E, of the phase currents, and the selection of the harmonics of order i, in the control signal making it possible to reduce the harmonics of order i of the phase currents as much as possible.

[0065] According to one aspect of the invention, the mapping step then comprises the storage of all the pairs: - Operating situation: the torque setpoint, and the combination of adjustment of the N characteristics of the rotating electrical machine chosen. - Components of the harmonics of order i, ie E of the control signal allowing to reduce as much as possible the components of order i, ie E of the phase currents in the operating situation.

[0066] According to one aspect of the invention, the open loop control comprises, during operation: - A step of measuring the operating situation, namely the current value of the N characteristics of the chosen rotating electrical machine, - A step of determining the torque setpoint for the rotating electrical machine, - The choice in the storage memory of the closest operating situation achieved during the calibration step, - The application in the control signal of the components of order i, ie E associated by mapping with the chosen operating situation.

[0067] Alternatively, the harmonics of order i, i.e. E applied in the control signal can be obtained from the harmonics of order i, i.e. E stored in memory by any other means, for example by comparing the current operating situation to several stored operating situations, and by weighting the harmonics of order i, i.e. E of these stored operating situations.

[0068] According to one aspect of the invention, the harmonics of order i, ie E, of the control signal are control voltages VBOdqi expressed in the frame (d, q).

[0069] According to one aspect of the invention, the step of characterizing the rotating machine comprises a modeling step.

[0070] According to one aspect of the invention, the modeling step comprises the analysis of the links between the control signal and the output phase currents, and the creation of a mathematical law linked to the design of the machine and taking into account the operating characteristics of the machine making it possible to determine, from a given usage situation, the odd harmonics of order 3 or higher of the phase control voltage making it possible to minimize the odd harmonics of order 3 or higher of the phase currents.

[0071] According to one aspect of the invention, the mathematical model thus determined is stored in the control unit of the machine.

[0072] According to one aspect of the invention, the open-loop control with modeling comprises, during operation: - A step of measuring the operating situation (speed, position, T°, direct voltage of the B+ network), namely the current value of the N characteristics of the chosen rotating electrical machine, - A step of determining the torque setpoint for the rotating electrical machine, - A step of calculating the components at the frequencies of the order harmonics i, i GE, of the control signal from the measured characteristics and the torque setpoint, using the stored mathematical model.

[0073] According to one aspect of the invention, the step of determining the torque setpoint can be carried out during the step of acting on the fundamental of the phase current.

[0074] In particular, the torque setpoint can be determined by using the current vector Idqf in the base (d, q) obtained during the step of action on the fundamental of the phase current.

[0075] According to one aspect of the invention, the harmonics of order i, i GE, of the control signal are control voltages VBOdqi expressed in the frame (d, q).

[0076] According to one aspect of the invention, this method makes it possible to limit the memory space used. Indeed, it is sufficient to store the mathematical model, and not all of the mapping data.

[0077] According to one aspect of the invention, this method also has a lower computing power cost than closed-loop control.

[0078] According to one aspect of the invention, the use of open-loop control makes it possible to regulate harmonics of rank greater than or equal to 3 for rotation speeds of the electrical machine greater than the maximum closed-loop speed Nmax. However, this method is less robust against disturbances.

[0079] According to one aspect of the invention, the step of determining the components at the frequencies of the odd order harmonics greater than or equal to 3 phase currents is carried out both online using sensors, and by a characterization step carried out offline by mapping and / or by modeling. This is then referred to as weighting control.

[0080] According to one aspect of the invention, the control method comprises, for each harmonic of order i, i GE, the control voltage VBOdqi of open-loop control from the data obtained offline, and from the measurement of the condition of use.

[0081] According to one aspect of the invention, the control method also comprises the closed-loop control voltage VBFdqf from the online measurement of the phase currents.

[0082] According to one aspect of the invention, a weighted sum of the open-loop and closed-loop control voltages is then used as the control voltage of the electrical machine.

[0083] According to one aspect of the invention, the weighting of the open-loop and closed-loop control voltages depends on the operating condition, in particular the rotation speed of the electrical machine.

[0084] According to one aspect of the invention, the weighting of the open-loop and closed-loop control voltages is different depending on the harmonic considered.

[0085] According to one aspect of the invention, the control voltage of the harmonic of order i Vdqi is equal to the closed-loop control voltage VBFdqi when the rotating machine rotates at low rotation speed, in particular a rotation speed lower than the maximum rotation speed Nmax_i allowing closed-loop control for this harmonic.

[0086] According to one aspect of the invention, the control signal is equal to the open-loop control signal when the rotation speed of the rotating machine is greater than the maximum rotation speed Nmax_i allowing closed-loop control for this harmonic.

[0087] According to one aspect of the invention, the control voltage of the harmonic of rank i Vdqi can therefore be obtained by acquiring the phase currents and closed-loop control, by measuring the usage situation and by open-loop control, or by weighting control weighting open-loop control and closed-loop control according to the usage situation.

[0088] According to one aspect of the invention, the control voltage of the harmonic of rank i Vdqi is the control voltage making it possible to generate in the rotating machine a phase current of the frequency of the harmonic of rank i, with an amplitude defined to cancel or reduce the harmonics and in phase opposition with it.

[0089] According to one aspect of the invention, the step of acting on the harmonic of rank i comprises an inverse rotation of angle i0, making it possible to obtain a control voltage Va[3i in the frame of reference (a, |3).

[0090] According to one aspect of the invention, the control voltages Va[3i of the harmonics of rank i, i.e. E, are sinusoidal with frequencies fi = i*f, with f the frequency of the fundamental.

[0091] According to one aspect of the invention, the signal making it possible to return to a predetermined setpoint, for example zero, all of the harmonics of the phase currents is the sum of the signals making it possible to return each of these harmonics to a predetermined setpoint, for example zero.

[0092] According to one aspect of the invention, the step of acting on the odd harmonics of rank 3 or higher of the phase currents comprises a step of summing the control voltages Va[3i of the harmonics of order i in the frame (a, |3). A control voltage of the harmonics is then obtained:

[0093] Va[3h = S Va[3hi

[0094] with ie E.

[0095] According to one aspect of the invention, in the case of a double-three-phase machine, the step of action on the harmonics of order i, with ie E, comprises two inverse Clarke transformations, making it possible to obtain two control voltages of the harmonics of order i of the current of the phases Vq>123h and Vq>456h.

[0096] According to one aspect of the invention, the control method comprises a step of summing the control voltages of the fundamental of the phases Vq>123f and Vq>456f, and the control voltages of the harmonics of order i of the current of the phases Vq>123h and Vq>456h, to obtain the control voltages of the phases of the rotating machine Vq>123 and Vq>456.

[0097] Vcpl23 = V <pl23f + Vcpl23h, et Vcp456 = Vcp456f + Vcp456h

[0098] According to one aspect of the invention, in the case of a three-phase machine, the step of action on the harmonics of order i, with ie E, comprises an inverse Clarke transformation, making it possible to obtain the control voltage of the harmonics of order i of the phase current Vq>123h

[0099] In this case, the control voltage of the phases of the rotating machine Vq>123 is the sum of the control voltage of the fundamental of the phases Vq>123f, and of the control voltage of the harmonics of order i of the current of the phases Vq>123h.

[0100] Vq>123 = Vq>123f + Vq>123h

[0101] Adding a harmonic control signal to the fundamental torque control signal of the rotating machine necessarily adds a risk of error. This error may, for example, be due to a failure of the sensors measuring the phase currents or the operating conditions.

[0102] According to one aspect of the invention, the harmonic compensation control signal is of lower amplitude than the fundamental control signal, in particular of amplitude at least 4 times lower than the amplitude of the fundamental control signal.

[0103] According to one aspect of the invention, the harmonic compensation control signal is filtered, and is only used in the control when its amplitude is lower than a threshold amplitude.

[0104] According to one aspect of the invention, this threshold amplitude is fixed.

[0105] Alternatively, this threshold amplitude is a fraction of the fundamental control signal amplitude, in particular less than 15%, for example equal to 10%.

[0106] The invention also relates to a voltage control unit for a rotating electrical machine comprising phases, the voltage control unit controlling the rotating electrical machine using a control method comprising a step of acting on the odd harmonics of order 3 and higher of the phase currents.

[0107] According to one aspect of the invention, the control unit comprises at least one voltage sensor configured to acquire the voltages at the terminals of the phases.

[0108] According to one aspect of the invention, the control unit comprises at least one sensor configured to acquire the values ​​of the phase currents of the rotating electrical machine used in the control method.

[0109] According to one aspect of the invention, the control unit comprises at least one sensor configured to acquire characteristics of the rotating electrical machine of a condition of use of the rotating electrical machine.

[0110] The invention also relates to a rotating electrical machine comprising phases, the rotating electrical machine being controlled by a voltage control unit with a control method comprising a step of action on the odd harmonics of order 3 and higher of the phase currents.

[0111] Other characteristics, details and advantages of the invention will emerge more clearly on reading the description which follows on the one hand, and several examples of embodiment given for informational and non-limiting purposes with reference to the appended schematic drawings on the other hand, in which:

[0112] [Fig. 1] [Fig. 1] represents a rotating electrical machine / voltage control unit assembly according to the invention.

[0113] [Fig.2] [Fig.2] is a schematic representation of a control method of a rotating electrical machine comprising phases by a control unit according to a first embodiment of the invention

[0114] [Fig.3] [Fig.3] is a schematic representation of a control method of a rotating electrical machine comprising phases by a control unit according to a second embodiment of the invention

[0115] [Fig.4] [Fig.4] is a schematic representation of a control method of a rotating electrical machine comprising phases by a control unit according to a third embodiment of the invention

[0116] The features, variants and the different embodiments of the invention may be combined with each other, in various combinations, provided that they are not incompatible or mutually exclusive. In particular, variants of the invention may be imagined comprising only a selection of features described below in isolation from the other features described, if this selection of features is sufficient to confer a technical advantage and / or to differentiate the invention from the prior art.

[0117] [Fig. 1] shows an assembly 1 comprising a rotating electrical machine 2 and a voltage control unit 3. The rotating electrical machine is controlled by the voltage control unit with a control method as described in Figures 2 to 4.

[0118] The control unit comprises: - a voltage sensor 4 configured to acquire the voltages at the phase terminals. - a sensor configured 5 to acquire the values ​​of the phase currents of the rotating electrical machine used in the control method. - a temperature sensor 6, and a rotation speed sensor 7, configured to acquire characteristics of the rotating electrical machine of a condition of use of the rotating electrical machine.

[0119] Figures 2, 3 and 4 are schematic representations of methods of controlling 100 a rotating electrical machine comprising phases by a control unit according to different embodiments of the invention.

[0120] In these figures, the controlled rotating machine is double-three-phase. According to an embodiment not shown, the rotating machine can be three-phase.

[0121] The control method comprises a step of action on the odd harmonics of order 3 and higher of the currents of phases 101.

[0122] The control method 100 comprises a step of selection, not shown here, of a set E of the orders of the odd harmonics of order greater than or equal to 3 on which the step of action on the harmonics of order 3 and higher of the phase currents acts.

[0123] Here, the set E is for example the set E = {5;7}. The step of action on the harmonics of order 3 and higher of the phase currents is therefore a step of action on the harmonics of order i, with ie E, and consists of attenuating these harmonics by adapting the control voltages of the electrical machine.

[0124] This step of action on the harmonics 101 consists of modifying the sinusoidal control voltage of the rotating electrical machine into a non-sinusoidal control voltage, in particular into a control voltage comprising components at the frequencies of the harmonics of order i, with ie E.

[0125] The control method 100 comprises a step of determining the odd harmonics of order 3 or higher, in particular of order 5 and 7, of the phase currents of the rotating electrical machine under given conditions of use of the machine 102.

[0126] These harmonics added to the control signal in phase opposition with harmonics obtained during the determination step 102, with an amplitude defined to cancel or reduce the harmonics.

[0127] The addition of 5th and 7th order harmonics to the control voltage thus makes it possible to attenuate, or even eliminate, these harmonics in the phase currents of the rotating electrical machine, and therefore makes it possible to reduce the magnetic noise due to imperfections in the actual electrical machine and to increase the performance of the machine.

[0128] The harmonic action step 101 can act with a different weighting on harmonics of order 5 and 7.

[0129] [Fig.2] is a schematic representation of a method of controlling a rotating electrical machine comprising phases by a control unit according to an embodiment of the invention in which the step of determining the harmonics 102 is done online, namely during operation of the machine. This is then referred to as closed-loop control.

[0130] The determination step then comprises a step of acquiring the phase currents by sensors 103. These phase currents acquired by the sensors are sent to the input of a control unit.

[0131] The control method comprises a Clarke transformation step 104 of the phase currents acquired by the sensors, i.e. a projection of the quantities relating to the three phases onto two fixed axes (a, |3).

[0132] In the case represented here of a double-three-phase machine, two distinct Clarke transformations 104 are carried out for the phase currents Iq>123 and Iq>456 of the two groups of three phases. We therefore obtain two current vectors Ia[31 and Ia[32.

[0133] The control method comprises a step of controlling the torque of the rotating machine 105, consisting of a step of acting on the fundamental of the phase current.

[0134] The control method comprises a sum operation of the two current vectors 106, making it possible to obtain a signal Ia[3f independent of odd harmonics greater than 3, in particular harmonics 5 and 7:

[0135] Ia|3f = O.5*(Ia[31 + Ia[32)

[0136] In the case of a three-phase machine, not shown here, the control method comprises a step of projecting the currents of the three phases Iq>123 into the reference frame (a, |3), then filtering the vector Ia[3 obtained in order to obtain a vector used for the action on the fundamental of the phase current Ia[3f independent of the odd harmonics greater than 3.

[0137] The step of action on the fundamental of the phase current comprises a rotation of the axes 107 which converts the alternating components of the reference frame (a, |3) into continuous components along a direct axis and a quadrature axis (reference frame (d, q)) with respect to the magnetic flux produced by the rotor. We then obtain a current vector Idqf in the base (d, q).

[0138] This combination of the Clarke transformation with the rotation from the (a, |3) frame to the (d, q) frame is known as the Park transformation, allowing decoupling of the control.

[0139] The step of acting on the fundamental of the phase current comprises a step of controlling the fundamental of the phase current 108, taking as input the current vector Idqf in the base (d, q), and returning as output a control voltage of the fundamental VBFdqf in the base (d, q).

[0140] The step of acting on the fundamental of the phase current also comprises an inverse Park transformation, i.e. an inverse rotation 109, followed by two inverse Clarke transformations 110, allowing to obtain two control voltages of the fundamental of the sinusoidal phases Vq>123f and Vq>456f.

[0141] The step of action on the harmonics of order 5 and 7 101 comprises a step of transformation 115 of the phase currents acquired by the sensors making it possible to obtain an input vector independent of the fundamental of the phase currents.

[0142] The vector used for the action on the harmonics of the phase current is half the difference of the two current vectors Ia[31 and Ia[32, i.e.:

[0143] Ia|3h = 0.5 * (Ia[31 - Ia[32)

[0144] This current vector Ia[3h, expressed in the frame (a, |3), is independent of the fundamental of the phase currents, and involves harmonics of order greater than or equal to 3 of the phase currents.

[0145] The method for controlling the rotating electrical machine 101 comprises a step of action on the 5th order harmonic of the phase current 116, and a separate step of action on the 7th order harmonic of the phase current 117.

[0146] These steps are carried out separately, but according to the same method explained here more broadly as a step of action on a harmonic of order i, with i here being equal to 5 or to stiffening element

[0147] The step of action on the harmonic of order i 116, 117 of the phase current comprises a step of rotation of the axes 118 which converts the alternating components of the reference frame (a, |3) into continuous components along a direct axis and a quadrature axis (reference frame (d, q)) with respect to the magnetic flux produced by the rotor. Current vectors Idq5 and Idq7 are then obtained in the base (d, q).

[0148] The frequency of the harmonic of order i of the phase currents is i times higher than the frequency of the fundamental of the phase currents. Thus, if the rotation to convert the components of the fundamental Ia[3f expressed in the frame (a, |3) into the frame (d, q) is a rotation of angle 0, then the step of action on the harmonic of order i of the phase current comprises a rotation 118 of angle i0.

[0149] In the case, not shown here, of a three-phase machine, the step of action on the harmonic of order i of the phase current 101, with ie E, comprises a step of rotation of angle i0 of the axes which converts the alternating components of the reference frame (a, |3) into continuous components along a direct axis and an axis in quadrature (reference frame (d, q)) with respect to the magnetic flux produced by the rotor. We then obtain an unfiltered current vector Idqi_nf in the base (d, q). This current vector is said to be “unfiltered” because it is dependent on the fundamental of the phase currents, and on the harmonics of orders different from i.

[0150] The step of acting on the harmonic of rank i of the phase currents then comprises a step of filtering the current vector Idqi_nf, making it possible to obtain a current vector Idqi depending only on the harmonic of rank i of the phase current.

[0151] The step of acting on the harmonic of order i 116, 117 of the phase currents comprises a step of controlling the harmonic of order i of the phase currents 119, taking as input the current vector Idqi in the base (d, q), and returning as output a control voltage of the harmonic of order i VBFdqi in the base (d, q). This step generates a control voltage of the harmonic of order i VBFdqi making it possible to bring these components back to a predetermined setpoint, for example zero.

[0152] The action step on the harmonic of rank i 116, 117 comprises an inverse rotation of angle i0 120, making it possible to obtain a control voltage Va[3i in the frame (a, P).

[0153] The control voltages Va[3i of the harmonics are sinusoidal with frequencies

[0154] fi = i*f, with f the frequency of the fundamental

[0155] The signal making it possible to return to a predetermined setpoint, for example zero, all of the harmonics of the phase currents is the sum of the signals making it possible to return each of these harmonics to a predetermined setpoint, for example zero.

[0156] The step of action on the odd harmonics of rank 3 or higher of the phase currents 101 comprises a step of summing the control voltages Va[3i 121 of the harmonics of order i in the frame (a, |3). We then obtain a control voltage of the harmonics:

[0157] Va[3h = S Va[3hi

[0158] with ie E.

[0159] The use of a closed-loop control for the control of a harmonic is only possible for a rotation speed of the rotating electrical machine lower than a limit rotation speed Nmax_i dependent on the rank of the controlled harmonic, with:

[0160] v _ fEchant maxj Npts^Npp

[0161] With fEchant the sampling frequency of the sensors, Npts the number of samples for the harmonic, i the rank of the harmonic and Npp the number of pairs of poles of the rotating machine.

[0162] The step of action on the harmonics of order i 101 comprises two inverse Clarke transformations 122, making it possible to obtain two control voltages of the harmonics of order i of the current of the phases Vq>123h and Vq>456h.

[0163] The control method 100 comprises a step 130 of summing the control voltages of the fundamental of the phases Vq>123f and Vq>456f, and the control voltages of the harmonics of order i of the current of the phases Vq>123h and Vq>456h, to obtain the control voltages of the phases of the rotating machine Vq>123 and Vq>456.

[0164] Vcpl23 = V <pl23f + Vcpl23h, et Vcp456 = Vcp456f + Vcp456h

[0165] In the case not shown of a three-phase machine, the step of action on the harmonics of order i, with ie E, comprises an inverse Clarke transformation, making it possible to obtain the control voltage of the harmonics of order i of the phase current Vq>123h. In this case, the control voltage of the phases of the rotating machine Vq>123 is the sum of the control voltage of the fundamental of the phases Vq>123f, and of the control voltage of the harmonics of order i of the phase current Vq>123h.

[0166] Vcpl23 = V <pl23f + vcpl23h

[0167] Adding a harmonic control signal to the fundamental torque control signal of the rotating machine necessarily adds a risk of error. This error may, for example, be due to a failure of the sensors measuring the phase currents or the operating conditions.

[0168] The harmonic compensation control signal is of lower amplitude than the fundamental control signal, in particular of amplitude at least 4 times lower than the amplitude of the fundamental control signal.

[0169] In order to limit the risk of error, the harmonic compensation control signal is filtered, and is only used in the control when its amplitude is less than a fraction of the amplitude of the fundamental control signal, in particular less than 15%, for example equal to 10%.

[0170] [Fig.3] is a schematic representation of a method for controlling a rotating electrical machine comprising phases by a control unit according to an embodiment of the invention in which the step of determining the harmonics 102 comprises a step of characterizing the rotating machine carried out offline 160, namely upstream of the use of the machine. This is then referred to as open-loop control.

[0171] The step of characterizing the rotating machine 160 comprises the choice of N characteristics of the rotating electrical machine, these N characteristics being able to influence the harmonics of the phase currents, and being measured, estimated or acquired during the operation of the rotating machine.

[0172] These characteristics can be chosen from: the rotation speed of the machine, the temperature,...

[0173] The control voltages of the rotating machine are also dependent on the torque setpoint, i.e. the control setpoint of the fundamental of the phase current, and / or the rotation speed of the rotating machine.

[0174] According to one embodiment of the invention, the step of characterizing the rotating machine 160 comprises a mapping step 140.

[0175] The mapping step 140 comprises: - a calibration step consisting of a step of putting the machine into operation in a set of predetermined operating situations, each operating situation being defined by a torque setpoint, and by the combination of adjustment of the N characteristics of the rotating electrical machine chosen, - for each operation in an operating situation: • a measurement of the i-order harmonics of the phase currents • the selection of harmonics of order i, in the control signal allowing the maximum reduction of order i harmonics of phase currents. - storage of all pairs: - operating situation: the torque setpoint, and the combination of adjustment of the N characteristics of the chosen rotating electrical machine. • components of the i-order harmonics of the control signal allowing the i-order components of the phase currents to be reduced as much as possible in the operating situation.

[0176] Open loop control includes, during operation: - a step of measuring the operating situation, namely the current value of the N characteristics of the rotating electrical machine chosen, - a step of determining the torque setpoint for the rotating electrical machine, - the choice in the storage memory of the closest operating situation achieved during the calibration step, - the application in the control signal of the components of order i associated by mapping with the chosen operating situation.

[0177] The harmonics of order i of the control signal are control voltages VBOdqi expressed in the frame (d, q).

[0178] In an embodiment not shown, the harmonics of order i applied in the control signal can be obtained from the harmonics of order i stored in memory by any other means, for example by comparing the current operating situation to several stored operating situations, and by weighting the harmonics of order i of these stored operating situations.

[0179] In an embodiment not shown, the step of characterizing the rotating machine 160 comprises a modeling step. The modeling step comprises the analysis of the links between the control signal and the output phase currents, and the creation of a mathematical law linked to the design of the machine and taking into account the operating characteristics of the machine making it possible to determine from a given usage situation the odd harmonics of order 3 or higher of the phase control voltage allowing to minimize the odd harmonics of order 3 or higher of the phase currents.

[0180] The mathematical model thus determined is stored in the machine control unit, and the open-loop control with modeling comprises, during operation: - a step of measuring the operating situation (speed, position, torque setpoint, T°, direct voltage of the B+ network), namely the current value of the N characteristics of the chosen rotating electrical machine, - a step of determining the torque setpoint for the rotating electrical machine, - a step of calculating the components at the frequencies of the harmonics of order i, ie E, of the control signal from the measured characteristics and the torque setpoint, using the stored mathematical model.

[0181] This modeling method makes it possible to limit the memory space used. Indeed, it is sufficient to store the mathematical model, and not all of the mapping data. This method also has a lower cost in computing power than closed-loop control.

[0182] Furthermore, the use of open-loop control makes it possible to regulate harmonics of rank greater than or equal to 3 for rotation speeds of the electrical machine greater than the maximum closed-loop speed Nmax. However, this method is less robust against disturbances.

[0183] The step of determining the torque setpoint is carried out during the step of acting on the fundamental of the phase current, in particular by using the current vector Idqf in the base (d, q) obtained during the step of acting on the fundamental of the phase current 105.

[0184] [Fig.4] is a schematic representation of a method 100 for controlling a rotating electrical machine comprising phases by a control unit according to an embodiment of the invention in which the step of determining the harmonics is carried out both online using sensors, and offline by mapping and / or by modeling. This is then referred to as weighting control.

[0185] For reasons of readability, only the method of controlling harmonic i has been represented, with for example i = 5.

[0186] The control method comprises, for each harmonic of order i, ie E, the calculation 150 of the open-loop control voltage VBOdqi from the data obtained offline and the measurement of the usage condition.

[0187] The control method also includes a calculation 151 of the voltage of VBFdqi closed-loop control from online measurement of phase currents.

[0188] The control voltage of the electric machine comprises a weighted sum step 152 of the open-loop and closed-loop control voltages.

[0189] The weighting of the open-loop and closed-loop control voltages depends on the operating conditions, in particular the rotation speed of the electrical machine, and is different depending on the harmonic considered.

[0190] For example, the control voltage is equal to the closed-loop control voltage when the rotating machine is rotating at low rotational speed, below the maximum rotational speed Nmax_i allowing closed-loop control for this harmonic.

[0191] The control signal is equal to the open-loop control signal when the rotational speed of the rotating machine is greater than the maximum rotational speed Nmax_i allowing closed-loop control for this harmonic.

[0192] Thus, the control voltage of the harmonic of rank i Vdqi can be obtained by an acquisition of the phase currents and a closed-loop control as illustrated in [Fig.2], by a measurement of the usage situation and by an open-loop control as illustrated in [Fig.3], or by a weighting control weighting open-loop control and closed-loop control according to the usage situation as in [Fig.4].

[0193] The control voltage of the harmonic of rank i Vdqi is the control voltage making it possible to generate in the rotating machine a phase current of the frequency of the harmonic of rank i, with an amplitude defined to cancel or reduce the harmonics and in phase opposition with it.

Claims

Claims

1. Method of controlling (100) a rotating electrical machine comprising phases by a control unit, the control method comprising a step of acting on the odd harmonics of order 3 and higher of the currents of the phases (101).

2. Control method (100) according to claim 1, in which the step of acting on the odd harmonics of orders 3 and higher (101) can act with a different weighting on the different harmonics, in particular the step of acting on the harmonics can act differently on the harmonics of orders 5 and 7.

3. Control method (100) according to one of the preceding claims, comprising a step of determining the odd harmonics of order 3 or higher, in particular of order 5 and 7, of the phase currents of the rotating electrical machine under given conditions of use of the machine (102).

4. Control method (100) according to claim 3, in which the step of determining the odd harmonics of orders 3 and higher, in particular of orders 5 and 7 of the phase currents (102), is done online, namely during operation of the machine.

5. Control method according to claim 4, in which the step of acting on odd harmonics of orders 3 or higher (101), in particular of orders 5 and 7, comprises a step of transforming (104) phase currents acquired by sensors making it possible to obtain an input vector independent of the fundamental of the phase currents.

6. Control method according to claim 3, in which the step of determining the components at the frequencies of the odd harmonics of order 3 or higher of the phase currents (102) comprises a step of characterizing the rotating machine carried out offline (160), namely upstream of the use of the machine.

7. Control method according to claim 6, in which the control voltages are dependent on a selection of N characteristics of the rotating electrical machine which can influence the harmonics of the phase currents, and being measured, estimated or acquired during the operation of the rotating machine.

8. Control method according to one of claims 6 and 7, in which the step of characterizing the rotating electrical machine (160) is carried out by mapping.

9. Control method according to one of claims 6 to 7, in which the step of characterizing the rotating electrical machine (160) is carried out by modeling.

10. Control method according to claim 9, in which the modeling step comprises the analysis of the links between control signal and output phase currents, and the creation of a mathematical law linked to the design of the machine and taking into account the operating characteristics of the machine making it possible to determine from a given usage situation the odd harmonics of order 3 or higher of the phase control voltage making it possible to minimize the odd harmonics of order 3 or higher of the phase currents.

11. Control method according to one of the preceding claims, in which the step of determining the components at the frequencies of the odd order harmonics greater than or equal to 3 of the phase currents (102) is carried out both online using sensors, and offline by mapping and / or by modeling.

12. Voltage control unit (3) of a rotating electrical machine (2) comprising phases, the voltage control unit controlling the rotating electrical machine using a control method comprising a step of acting on the odd harmonics of order 3 and higher of the phase currents.

13. Voltage control unit (3) according to claim 12 comprising at least one sensor (5) configured to acquire the values ​​of the phase currents of the rotating electrical machine used in the control method.

14. Voltage control unit (3) according to one of claims 12 to 13, comprising at least one sensor (6, 7) configured to acquire characteristics of the rotating electrical machine of a condition of use of the rotating electrical machine.

15. Rotating electrical machine (2) comprising phases, the rotating electrical machine being controlled by a voltage control unit (3) with a control method comprising a step of acting on the odd harmonics of order 3 and higher of the phase currents.

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