JP5146958B2 - Control device for electric motor system - Google Patents

Description

  The present invention includes an electric motor including two rotors each having a permanent magnet for generating a field magnetic flux, and phase difference change driving means for applying a driving force for performing relative rotation between the rotors between the rotors. The present invention relates to a control device for an electric motor system provided.

  As the control device for this type of electric motor system, for example, those found in Patent Documents 1 and 2 have been proposed by the applicant of the present application.

  The electric motors found in these Patent Documents 1 and 2 are coaxially provided with an inner rotor and an outer rotor, which are two rotors each having a permanent magnet for generating a field magnetic flux, and an output shaft. In this case, the outer rotor and the output shaft are integrally connected to be rotatable, and the inner rotor is provided to be rotatable relative to the outer rotor and the output shaft. And in these patent documents 1 and 2, by the actuator apparatus which has a planetary gear mechanism (patent document 1), or by the hydraulic actuator apparatus which has the oil chamber formed inside the inner rotor (patent document) 2) The inner rotor is rotated relative to the outer rotor and the output shaft, and the phase difference between the two rotors is changed as appropriate.

In Patent Documents 1 and 2, the phase difference between the rotors is estimated, and the actuator device is operated so that the estimated value of the phase difference matches the required target value. In this case, in order to estimate the phase difference between the two rotors, the armature current and the armature voltage in the dq coordinate system in the so-called dq vector control (the detected values of the d-axis current and the q-axis current and the q-axis voltage Command value) and the observed value of the rotational speed of the output shaft of the motor, an estimated value of the induced voltage constant of the motor is calculated based on a relational expression established therebetween. The phase difference between the rotors is estimated from the estimated value of the induced voltage constant.
JP 2007-28889A JP 2008-29123 A

  By the way, when the motor is operated in a high speed range where the rotation speed of the output shaft of the motor is relatively high, iron loss (hysteresis loss and eddy current loss) becomes relatively large. However, in Patent Documents 1 and 2, the influence of this iron loss is not taken into account when estimating the induced voltage constant of the motor. For this reason, when the electric motor is operated in a high speed range, an error in the estimated value of the induced voltage constant becomes large, and the induced voltage constant is estimated to a value smaller than the actual value. As a result, when the phase difference between the two rotors is controlled so that the estimated value of the phase difference between the two rotors corresponding to the estimated value of the induced voltage constant matches the target value, the output torque of the electric motor is greater than the target torque. However, there is a disadvantage that the motor efficiency becomes excessive or the efficiency of the electric motor decreases.

  The present invention has been made in view of such a background, and can accurately perform operation control of an electric motor system while accurately estimating an induced voltage constant of an electric motor including two rotors and a phase difference between the two rotors. An object of the present invention is to provide a control device for an electric motor system.

In order to achieve this object, the motor system control apparatus of the present invention rotates integrally with the first rotor and the second rotor each having a permanent magnet for generating a field magnetic flux, and the first rotor of the two rotors. And an output motor provided coaxially with each other, and an electric motor provided so that the second rotor can rotate relative to the first rotor, and a driving force for causing the second rotor to rotate relative to each other. And a phase difference change driving means for changing the phase difference between the two rotors by applying to the motor, an induced voltage constant of the motor as a characteristic parameter of the motor or an actual phase difference between the two rotors. Is a control device that controls the operation of the electric motor system using the estimated value of the characteristic parameter, and has a correlation with the iron loss of the electric motor. Characteristic parameter estimating means for acquiring a target value or an observed value of each of a plurality of state quantities of a predetermined type of the motor including a quantity, and obtaining an estimated value of the characteristic parameter based on the obtained values of the plurality of state quantities It shall be the basic configuration that with.

According to such a basic configuration , the characteristic parameter estimation unit is configured to generate the characteristic based on a target value or an observed value of each of the predetermined types of state quantities including a state quantity having a correlation with the iron loss of the electric motor. Estimate the parameter (induced voltage constant or phase difference between both rotors). For this reason, the estimated value of the characteristic parameter can be obtained with high accuracy even in an operating state of the motor that compensates for the influence of the iron loss of the motor and that has a relatively large iron loss.

Therefore, according to the basic configuration, it is possible to accurately control the operation of the motor system using the estimated value while accurately estimating the induced voltage constant of the motor including two rotors and the phase difference between the two rotors. it can. As a result, the required operation of the electric motor can be performed stably and efficiently.

In the present invention , more specifically, a target value of the current of the armature winding of the motor is set, and the current of the armature winding is controlled so that the observed value of the current matches the target value. An energization control unit; and a rotor phase difference control unit that sets the target value of the characteristic parameter and controls the phase difference change driving unit so as to match the estimated value of the characteristic parameter with the target value. In this case, as the plurality of state quantities of values characteristic parameter estimating means obtains a target value or the observed value of the voltage of at least the motor armature windings, the target value or the observation of the current in the armature winding Values, observed values of the rotational speed of the output shaft of the motor, and target values of the characteristic parameters. In this case, the characteristic parameter estimation means, the observation of the rotational speed of the output shaft of the target value of the voltage of the motor armature winding or observed value and the target value of the current of the armature winding or observed value and the electric motor A basic estimated value calculating means for obtaining a basic estimated value of the characteristic parameter based on a predetermined relationship established between the voltage, current and rotational speed and the characteristic parameter when there is no iron loss of the motor And at least the target value of the characteristic parameter and the observed value of the rotational speed of the output shaft of the electric motor are used as the value of the state quantity correlated with the iron loss, and the value of the state quantity correlated with the iron loss. that is composed of a correcting means for obtaining an estimated value of the characteristic parameters by correcting the basic estimated value according to (first invention).

  The “observed value” may be a detected value using an appropriate sensor, but may be a value estimated by an observer using an appropriate model. The voltage or current of the armature winding may be the voltage (phase voltage) or (phase current) of the armature winding of each phase of the motor, but the phase voltage or phase current is It may be a voltage or current obtained by coordinate conversion into an appropriate coordinate system (for example, a dq coordinate system that is a rotating coordinate system or an α-β coordinate system that is a stationary coordinate system).

According to the first invention , the basic estimated value is obtained by the basic estimated value calculating means as the estimated value of the characteristic parameter when it is assumed that there is no iron loss of the electric motor. The correcting means corrects the basic estimated value in accordance with the target value of the characteristic parameter and the observed value of the rotational speed of the output shaft of the motor, thereby obtaining the estimated value of the characteristic parameter. In this case, the iron loss of the electric motor has a particularly high correlation between the rotation speed of the output shaft of the electric motor and the strength of the field magnetic flux generated by the permanent magnets of both the rotors (the combined field magnetic flux for both rotors). . The strength of the field magnetic flux is closely related to the induced voltage constant as the characteristic parameter or the phase difference between the two rotors. That is, the strength of the field magnetic flux changes depending on the phase difference between the two rotors, and the induced voltage constant changes depending on the strength of the field magnetic flux.

Therefore, according to the first invention , the basic estimated value of the characteristic parameter is corrected according to the observed value of the rotational speed of the output shaft of the motor and the target value of the characteristic parameter, thereby reducing the influence of the iron loss of the motor. It is possible to appropriately compensate and to appropriately obtain the estimated value of the characteristic parameter.

  When the both rotors of the motor are non-salient rotors, the magnetic flux generated by the permanent magnets of the rotors (synthetic field) is provided. The direction of the magnetic flux) is the d-axis (so-called field axis), and the direction orthogonal to the d-axis is the q-axis (so-called torque axis). The current is normally controlled to increase as the rotational speed of the output shaft of the motor increases (so-called field weakening control is performed). For this reason, the d-axis current is closely related to the rotation speed of the output shaft of the electric motor and varies depending on the rotation speed. Accordingly, when the basic estimated value is corrected to obtain the estimated value of the characteristic parameter as in the second aspect of the invention, in the correction process, instead of the observed value of the rotational speed of the output shaft of the motor, the d It is also possible to use a target value or an observed value of the axial current.

Therefore, another aspect of the present invention, prior Symbol basic configuration, sets a target value of the current in the armature winding of the motor, the armature winding to match the observed value of the current to the target value Energization control means for controlling the current of the wire, and inter-rotor phase difference control for setting the target value of the characteristic parameter and controlling the phase difference change driving means so that the estimated value of the characteristic parameter matches the target value together and means, the rotors of the electric motor in the case of a non-salient pole type rotor, as the values of a plurality of state quantities characteristic parameter estimating means obtains, of at least the electric motor armature windings A target value or observed value of voltage, a target value or observed value of current of the armature winding, an observed value of rotational speed of the output shaft of the motor, and a target value of the characteristic parameter are included. , The electric The target value or the observed value of the winding current is d in the dq coordinate system in which the direction of the field magnetic flux generated by the permanent magnets of the two rotors is the d axis and the direction orthogonal to the d axis is the q axis. A target value or an observed value of the d-axis current that is the current component in the axial direction may be included. Then, in this case, the characteristic parameter estimation means, the output shaft of the target value of the voltage of the motor armature winding or observed value and the target value of the current of the armature winding or observed value and the electric motor Based on the observed value of the rotational speed, a basic estimation value of the characteristic parameter is obtained based on a predetermined relationship established between the voltage, current, rotational speed and the characteristic parameter when there is no iron loss of the motor. A state having a correlation with the iron loss by using the estimated value calculation means and at least the target value of the characteristic parameter and the target value or the observed value of the d-axis current as a value of the state quantity correlated with the iron loss. that is composed of a correcting means for obtaining an estimated value of the characteristic parameters by depending on the value of the quantity for correcting the basic estimated value (second invention).

In the second invention , when the basic estimated value is corrected by the correcting means, only the target value or the observed value of the d-axis current is used instead of the observed value of the rotational speed of the output shaft of the motor. This is different from the first invention . For this reason, similarly to the first invention , it is possible to appropriately compensate for the influence of the iron loss of the motor and to appropriately obtain the estimated value of the characteristic parameter.

Supplementally, in the first invention or the second invention , the target value of the armature winding of the motor includes, for example, at least a target value of the output torque of the motor and an observed value of the rotational speed of the output shaft of the motor. It may be set by a map or the like according to the estimated value of the characteristic parameter. The target value of the characteristic parameter may be set by a map or the like according to at least the target value of the output torque of the motor and the observed value of the rotational speed of the output shaft of the motor.

In the first invention or the second invention , the value of the plurality of state quantities acquired by the characteristic parameter estimation means further includes a target value of the output torque of the motor, and the correction means In order to correct the estimated value, it is preferable to further use a target value of the output torque of the electric motor as the value of the state quantity having a correlation with the iron loss ( third invention ).

That is, the iron loss of the electric motor is also affected by the magnetic flux generated by the current flowing through the armature winding of the electric motor. Then, the current of the armature winding of the electric motor is normally controlled so as to generate a target output torque in the electric motor. Therefore, in the third aspect of the invention , the correction means adds to the target value of the characteristic parameter and the observed value of the rotational speed of the output shaft of the motor, or the target value of the characteristic parameter and the target value of the d-axis current or In addition to the observed value, the target value of the output torque of the electric motor is used as the value of the state quantity correlated with the iron loss, and the basic estimated value is set according to the value of the state quantity correlated with the iron loss. By correcting, an estimated value of the characteristic parameter is obtained.

As a result, according to the third aspect of the invention, it is possible to more appropriately compensate for the influence of the iron loss of the electric motor, and to further improve the accuracy of the estimated value of the characteristic parameter. As a result, the characteristic parameter can be controlled to the target value with higher accuracy.

  Further, when attention is paid to the q-axis current that is the current component in the q-axis direction in the dq coordinate system, the q-axis current is a current component that causes the motor to generate torque, and thus the target value of the output torque of the motor. It is controlled to increase as the value increases. For this reason, the q-axis current is closely related to the output torque of the electric motor and changes depending on the target value of the output torque. Therefore, when correcting the basic estimated value, the target value or the observed value of the q-axis current is used instead of the target value of the output torque of the motor as the value of the state quantity correlated with the iron loss. Is also possible.

Therefore, in the first invention or the second invention , the target value or the observed value of the current of the armature winding includes the target value of the q-axis current that is the current component in the q-axis direction in the dq coordinate system, or When an observed value is included, the correcting means corrects the basic estimated value by using a target value or an observed value of the q-axis current as a state quantity value correlated with the iron loss. May be further used ( fourth invention ).

According to the fourth aspect of the present invention , when the basic estimated value is corrected by the correcting means, only the target value or the observed value of the q-axis current is used instead of the target value of the output torque of the motor . This is different from the invention . For this reason, similarly to the third invention , the influence of the iron loss of the electric motor can be more appropriately compensated, and the accuracy of the estimated value of the characteristic parameter can be further improved.

  An embodiment of a control device for an electric motor system of the present invention will be described with reference to FIGS. First, with reference to FIG. 1, the mechanical structure of the principal part of the electric motor with which the electric motor system of this embodiment was provided is demonstrated. FIG. 1 is a view of the main part of the electric motor as viewed in the axial direction of the electric motor.

  The electric motor 1 is a DC brushless motor having a double rotor structure, and includes an output shaft 2, an outer rotor 3, and an inner rotor 4 coaxially. The outer rotor 3 and the inner rotor 4 correspond to the first rotor and the second rotor in the present invention, respectively. Outside the outer rotor 3, there is a stator 5 fixed to the housing (not shown) of the electric motor 1, and the stator 5 has armature windings (three-phase armature windings) not shown. It is installed. The electric motor 1 is mounted on the vehicle, for example, as a driving force generation source for a hybrid vehicle or an electric vehicle (not shown).

  The outer rotor 3 is formed in an annular shape, and includes a plurality of permanent magnets 6 arranged at substantially equal intervals in the circumferential direction. In the present embodiment, the permanent magnet 6 is formed in a long rectangular plate shape, the longitudinal direction thereof is directed to the axial direction of the outer rotor 3, and the normal direction is directed to the radial direction of the outer rotor 3. And embedded in the outer rotor 3.

  The inner rotor 4 is also formed in an annular shape. The inner rotor 4 is disposed coaxially with the outer rotor 3 inside the outer rotor 3. The output shaft 2 passes through the axial center portion of the inner rotor 4 coaxially with the inner rotor 4 and the outer rotor 3.

  In this case, the output shaft 2 is connected to the outer rotor 3 via a connecting member (not shown) provided on one end side or both sides of the inner rotor 4 in the axial direction, and is rotatable integrally with the outer rotor 3. . The inner rotor 4 is provided so as to be rotatable relative to the outer rotor 3 and the output shaft 2, and the phase difference between the rotors 3 and 4 can be changed by the relative rotation.

  Further, the inner rotor 4 includes a plurality of permanent magnets 8 arranged at substantially equal intervals in the circumferential direction. In the present embodiment, the permanent magnet 8 has the same shape as the permanent magnet 6 of the outer rotor 3 and is embedded in the inner rotor 4 in the same manner as in the case of the outer rotor 3. The number of permanent magnets 8 is the same as that of the permanent magnets 6 of the outer rotor 3.

  In the present embodiment, since the outer rotor 3 and the inner rotor 4 are cylindrical, they are non-salient rotors.

  Here, in FIG. 1, the permanent magnets 6 a shown in white among the permanent magnets 6 of the outer rotor 3 and the permanent magnets 6 b indicated by stippling are opposite in the direction of the magnetic poles in the radial direction of the outer rotor 3. It has become. For example, the permanent magnet 6a has an N pole on the outer side (outer peripheral surface side of the outer rotor 3) and an S pole on the inner side (inner peripheral surface side of the outer rotor 3), and the permanent magnet 6b has an outer side. This surface is the S pole and the inner surface is the N pole. Similarly, the permanent magnet 8a shown in white among the permanent magnets 8 of the inner rotor 4 and the dotted permanent magnet 8b are opposite to each other in the direction of the magnetic poles in the radial direction of the inner rotor 4. . For example, the permanent magnet 8a has an N-pole surface on the outer side (the outer peripheral surface side of the inner rotor 4) and an S-pole surface on the inner side (the inner peripheral surface side of the inner rotor 4). This surface is the S pole and the inner surface is the N pole.

  In the present embodiment, in the outer rotor 3, a pair of permanent magnets 6 a and 6 a adjacent to each other and a pair of permanent magnets 6 b and 6 b adjacent to each other are alternately arranged in the circumferential direction of the outer rotor 3. It is arranged. Similarly, in the inner rotor 4, pairs of permanent magnets 8 a and 8 a adjacent to each other and pairs of permanent magnets 8 b and 8 b adjacent to each other are alternately arranged in the circumferential direction of the inner rotor 4. .

  In the electric motor 1 configured as described above, the inner rotor 4 is rotated with respect to the outer rotor 3, and the phase difference between the rotors 3 and 4 (hereinafter referred to as inter-rotor phase difference θd) is changed. Thus, the strength of the combined field magnetic flux formed by combining the field magnetic flux generated by the permanent magnets 8a and 8b of the inner rotor 4 and the field magnetic flux generated by the permanent magnets 6a and 6b of the outer rotor 3 (in the stator 5). The strength of the magnetic flux in the radial direction is changed. Hereinafter, a state where the strength of the combined field magnetic flux is maximum is referred to as a field maximum state, and a state where the strength of the combined field magnetic flux is minimum is referred to as a field minimum state.

  2A is a diagram showing a phase relationship between the inner rotor 4 and the outer rotor 3 in the maximum field state, and FIG. 2B is a diagram showing the relationship between the inner rotor 4 and the outer rotor 3 in the field minimum state. It is a figure which shows a phase relationship.

  As shown in FIG. 2A, the field maximum state is a state in which the permanent magnets 8a and 8b of the inner rotor 4 and the permanent magnets 6a and 6b of the outer rotor 3 are opposed to each other. More specifically, in this field maximum state, the permanent magnet 8 a of the inner rotor 4 faces the permanent magnet 6 a of the outer rotor 3, and the permanent magnet 8 b of the inner rotor 4 faces the permanent magnet 6 b of the outer rotor 3. In this state, in the radial direction, the direction of the magnetic flux Q1 of the permanent magnets 8a and 8b of the inner rotor 4 and the direction of the magnetic flux Q2 of the permanent magnets 6a and 6b of the outer rotor 3 are the same. The strength of the combined magnetic flux Q3 of the magnetic fluxes Q1 and Q2 (the strength of the combined field magnetic flux) is maximized.

  Further, as shown in FIG. 2B, the field minimum state is a state in which the permanent magnets 8a and 8b of the inner rotor 4 and the permanent magnets 6a and 6b of the outer rotor 3 face each other. More specifically, in this field minimum state, the permanent magnet 8 a of the inner rotor 4 faces the permanent magnet 6 b of the outer rotor 3, and the permanent magnet 8 b of the inner rotor 4 faces the permanent magnet 6 a of the outer rotor 3. In this state, the direction of the magnetic flux Q1 of the permanent magnets 8a and 8b of the inner rotor 4 and the direction of the magnetic flux Q2 of the permanent magnets 6b and 6a of the outer rotor 3 are opposite in the radial direction. The strength of the combined magnetic flux Q3 of these magnetic fluxes Q1 and Q2 (the strength of the combined field magnetic flux) is minimized.

  In this embodiment, the inner rotor 4 is relative to the outer rotor 3 within a range between a rotational position where the combined field magnetic flux is in the maximum field state and a rotational position where the field is in the minimum state. It can be rotated. The relative rotatable range, that is, the changeable range of the inter-rotor phase difference θd is, for example, an electric angle of 180 [deg]. The boundary of the range is mechanically defined by, for example, contact between a member that can rotate integrally with the inner rotor 4 and a member that can rotate integrally with the outer rotor 3.

  In this embodiment, the inter-rotor phase difference θd in the maximum field state is defined as 0 [deg], and the inter-rotor phase difference θd in the minimum field state is defined as 180 [deg]. However, it is not necessary to define the inter-rotor phase difference θd in the maximum field state as 0 [deg], and the zero point and scale of the inter-rotor phase difference θd may be arbitrarily set.

  As described above, the induced voltage constant Ke of the electric motor 1 is changed by changing the rotor phase difference θd to increase or decrease the strength of the combined field magnetic flux. The induced voltage constant Ke is a proportional constant that defines the relationship between the angular velocity of the output shaft 2 of the electric motor 1 and the induced voltage (effective value) generated in the armature according to the angular velocity. FIG. 3 is a graph illustrating the relationship between the induced voltage constant Ke of the electric motor 1 of the present embodiment and the inter-rotor phase difference θd. As illustrated, the value of the induced voltage constant Ke of the electric motor 1 becomes smaller as the inter-rotor phase difference θd is increased from 0 [deg] to 180 [deg]. This is because with the increase of θd, the strength of the combined field magnetic flux becomes weaker, and as a result, the induced voltage (counterelectromotive voltage) of the armature becomes smaller when the rotational angular velocity of the output shaft 2 is constant. . Therefore, the value of the induced voltage constant Ke serves as an index indicating the strength of the combined field magnetic flux, and the value of the dielectric voltage constant Ke increases as the strength of the combined field magnetic flux increases.

  Supplementally, the permanent magnets 6 and 8 may be arranged in other forms. For example, a plurality of rectangular plate-like permanent magnets provided in the outer rotor 3 are arranged at equiangular intervals in the circumferential direction of the outer rotor 3 with the normal direction (thickness direction) directed in the circumferential direction of the outer rotor 3. The magnetic poles of two opposing permanent magnets adjacent to each other in the circumferential direction of the outer rotor 3 have the same polarity (the magnetization directions of the two permanent magnets adjacent to each other are It is also possible to reverse the directions in the circumferential direction). Further, the changeable range of the inter-rotor phase difference θd does not necessarily need to be in the range of 180 [deg] in terms of electrical angle, and may be a range that is larger or smaller than that.

  In the present embodiment, the output shaft 2 and the outer rotor 3 of the electric motor 1 are configured to rotate integrally. However, the output shaft and the inner rotor are configured to rotate integrally so that the output shaft and the inner rotor rotate. You may comprise so that an outer rotor can rotate relatively with respect to a rotor.

  Next, with reference to FIG. 4, the phase difference change drive means for changing the inter-rotor phase difference θd of the electric motor 1 and the control device for controlling the operation of the electric motor 1 and the phase difference change drive means will be described. FIG. 4 is a block diagram showing a functional configuration of the control device. In this case, FIG. 4 shows the electric motor 1 and the phase difference change driving means in a simplified manner.

  Referring to FIG. 4, the electric motor system of the present embodiment includes a phase difference change driving means 10 that applies a driving force for rotating the inner rotor 4 of the electric motor 1 relative to the outer rotor 3 between the rotors 3 and 4. Prepare. Although not shown in detail, the phase difference changing drive means 10 includes an actuator 11 that generates a driving force and a phase variable mechanism 12 that transmits the driving force of the actuator 11 between the rotors 3 and 4. The

  Such a phase difference change driving means 10 can be constituted by a hydraulic device as shown in Patent Document 2, for example. In this case, the phase variable mechanism 12 forms an oil chamber in a space between the inner peripheral surface of the inner rotor 4 and the outer peripheral surface of the output shaft 2, and the rotor position is interlocked with the increase / decrease in the volume of the oil chamber. The phase difference θd is configured to change. A hydraulic power source device (a device including a pump, a pressure control valve and the like) that supplies and discharges hydraulic oil to and from the oil chamber is provided outside the electric motor 1 as the actuator 11.

  Or you may comprise the phase difference change drive means 10 by an apparatus as shown to the said patent document 1, for example. In this case, the phase variable mechanism 12 is constituted by a planetary gear mechanism, and an electric or hydraulic rotary actuator that inputs a rotational driving force to the planetary gear mechanism is provided outside the electric motor 1 as the actuator 11.

  The control device 50 that controls the operation of the motor system according to this embodiment including the phase difference change driving unit 10 and the motor 1 basically energizes the armature winding of the motor 1 by so-called dq vector control. To control. That is, the control device 50 is equivalent to the dq coordinate system in which the electric motor 1 is a coordinate system in which the field direction (the direction of the combined field magnetic flux) is the d axis and the direction orthogonal to the d axis is the q axis. Convert to circuit and handle. The equivalent circuit has an armature on the d-axis (hereinafter referred to as d-axis armature) and an armature on the q-axis (hereinafter referred to as q-axis armature). The dq coordinate system is a rotating coordinate system fixed with respect to the output shaft 2 of the electric motor 1. Then, the control device 50 generates an armature winding (for three phases) of the electric motor 1 so that the torque of the torque command value Tr_c (target value of the output torque of the electric motor 1) given from the outside is generated on the output shaft 2 of the electric motor 1. The armature winding) is controlled. Further, in parallel with the energization control, the control device 50 controls the inter-rotor phase difference θd via the phase difference change driving means 10 so that the induced voltage constant Ke of the electric motor 1 matches the required target value. To do.

  In order to perform these controls, the motor system of the present embodiment includes a current detection unit that detects currents in two phases of the three phases of the armature winding of the motor 1, for example, the U phase and the W phase. As rotation angle detection means for detecting the rotation angle of the output shaft 2 or the outer rotor 3 of the motor 1 (rotation angle in a coordinate system fixed to the stator 5 of the motor 1). And a resolver 43. The outputs (detected values) of the current sensors 41 and 42 and the resolver 43 are input to the control device 50. Thereafter, the current value of the U-phase armature winding detected by the current sensor 41 is the U-phase current detection value Iu_s, the current value of the W-phase armature winding detected by the current sensor 42 is the W-phase current detection value Iw_s, A value of the rotation angle of the output shaft 2 (= the rotation angle of the outer rotor 3) detected by the resolver 43 is referred to as an angle detection value θm_s.

  The control device 50 is an electronic circuit unit including a CPU, a memory, and the like, and its control processing is sequentially executed at a predetermined arithmetic processing cycle. The functional means of the control device 50 will be specifically described below.

  The control device 50 differentiates the angle detection value θm_s by the resolver 43 to obtain a speed detection value Nm_s as a detection value (observation value) of the rotation speed of the output shaft 2 of the electric motor 1 (= rotation speed of the outer rotor 3). A rotation speed calculation unit 51 to be obtained and an energization control unit 52 that controls the energization current of the armature windings of each phase of the electric motor 1 through an inverter circuit (not shown). The speed detection value Nm_s obtained by the rotation speed calculation unit 51 is a detection value of the rotation speed at the mechanical angle of the output shaft 2 in this embodiment, but by multiplying this by the number of pole pairs of the electric motor 1, You may make it obtain | require the detected value of the rotational speed in a corner | angular. The energization control unit 52 corresponds to energization control means in the present invention.

  The energization control unit 52 performs three-phase-dq conversion on the d-axis direction from the U-phase current detection value Iu_s and the W-phase current detection value Iw_s by the current sensors 41 and 42 and the angle detection value θm_s by the resolver 43. A detected value Id_s of a d-axis armature current (hereinafter referred to as d-axis current) as a current component and a detected value Iq_s of a q-axis armature current (hereinafter referred to as q-axis current) as a current component in the q-axis direction. A three-phase-dq converter 61 for calculation is provided. In the three-phase-dq conversion, a set of a U-phase current detection value Iu_s, a W-phase current detection value Iw_s, and a V-phase current detection value (= −Iu_s−Iw_s) obtained therefrom is used as an angle detection value θm_s. This is a process of converting into a set of a detected value Id_s of the d-axis current and a detected value Iq_s of the q-axis current by a conversion matrix according to (more specifically, the rotation angle of the output shaft 2 in electrical angle).

  The energization control unit 52 includes a current command calculation unit 62 that determines a d-axis current command value Id_c that is a command value for the d-axis current and a q-axis current command value Iq_c that is a command value for the q-axis current, A field control unit 63 for obtaining a correction value ΔIda for correcting the current command value Id_c, and a deviation ΔId () between a value (Id_c + ΔIda) obtained by correcting the d-axis current command value Id_c by this correction value ΔIda and a detected value Id_s of the d-axis current = Id_c + ΔIda−Id_s (hereinafter referred to as d-axis current deviation ΔId)), a power control unit 65 for obtaining a correction value ΔIqa for correcting the q-axis current command value Iq_c, and a q-axis based on the correction value ΔIqa And an arithmetic unit 66 for obtaining a deviation ΔIq (= Iq_c + ΔIqa−Iq_s, hereinafter referred to as q-axis current deviation ΔIq) between the corrected current command value Iq_c (Iq_c + ΔIqa) and the detected value Iq_s of the q-axis current. In the present embodiment, Id_c + ΔIda and Iq_c + ΔIqa correspond to the target value of the d-axis current and the target value of the q-axis current, respectively.

  Here, in the current command calculation unit 62, a torque command value Tr_c given to the control device 50 from the outside, a speed detection value Nm_s obtained by the rotation speed calculation unit 51, and a Ke estimation unit 53 described later are obtained. The estimated value Ke_e of the actual induced voltage constant Ke of the electric motor 1 (hereinafter referred to as the induced voltage constant estimated value Ke_e) is input. Then, the current command calculation unit 62 determines the d-axis current command value Id_c and the q-axis current command value Iq_c from these input values based on a preset map. The d-axis current command value Id_c and the q-axis current command value Iq_c have meanings as feed-forward command values for the d-axis current and the q-axis current for generating the torque command value Tr_c on the output shaft 2 of the electric motor 1. Have.

  The torque command value Tr_c is determined in accordance with, for example, the accelerator operation amount (depressing amount of the accelerator pedal) and the traveling speed of a vehicle (hybrid vehicle or electric vehicle) equipped with the electric motor 1 as a propulsive force generation source. The torque command value Tr_c includes a power running torque command value and a regenerative torque command value, and these command values have different positive and negative polarities.

  The correction value ΔIda determined by the field control unit 63 is such that the magnitude of the combined vector of the d-axis armature voltage and the q-axis armature voltage is the power supply voltage Vdc of the motor 1 (more specifically, the inverter circuit This means an operation amount (feedback operation amount) of the d-axis current so as to be within a voltage circle corresponding to the power supply voltage). The correction value ΔIda includes a d-axis voltage command value Vd_c and a q-axis voltage command value Vq_c (values determined in the previous calculation processing cycle) determined by a current feedback control unit 67, which will be described later, and the value of the power supply voltage Vdc. It is decided according to. For example, depending on the deviation between the magnitude of the combined vector of Vd_c and Vd_q determined in the previous calculation processing cycle and the target value (radius of the voltage circle) determined according to the power supply voltage Vdc, an appropriate feedback control law is used. The correction value ΔIda is determined.

  Further, the correction value ΔIqa determined by the power control unit 65 is the effect of the temperature change of the permanent magnets 6 and 8 and the temperature change of the armature on the output torque of the electric motor 1 during the operation of the electric motor 1. It is for compensation. When the temperature of the permanent magnets 6 and 8 changes, generally, even if the inter-rotor phase difference θd is constant, the induced voltage constant Ke of the electric motor 1 changes, and the resistance of the armature winding also changes. For this reason, even if the q-axis current command value Iq_c is constant, the output torque of the electric motor 1 changes due to the temperature change of the permanent magnets 6 and 8 and the armature. Therefore, in this embodiment, this influence is compensated by the q-axis current correction value ΔIq_a. The q-axis current correction value ΔIq_a is the resistance of the armature winding estimated from the sampling value of the U-phase current detection value Iu_s or the W-phase current detection value Iw_s, or the induced voltage constant obtained by the Ke estimation unit 53 described later. It is determined based on the estimated value Ke_e and the like. The power control unit 65 may be omitted. In that case, in the processing of the calculation unit 66, the deviation (= Iq_c−Iq_s) between the q-axis current command value Iq_c and the q-axis current detection value Iq_s may be obtained as the q-axis current deviation ΔIq. .

  The energization control unit 52 further uses the d-axis armature voltage command value (target value of the d-axis voltage) according to the d-axis current deviation ΔId and the q-axis current deviation ΔIq obtained by the calculation units 64 and 66, respectively. A current feedback control unit (current FB control unit) 67 that determines a certain d-axis voltage command value Vd_c and a q-axis voltage command value Vq_c that is a voltage command value (q-axis voltage target value) of the q-axis armature is provided. . The current feedback control unit 67 determines the d-axis voltage command value Vd_c by a feedback control law such as a PI control law (proportional / integral control law) so that the deviation ΔId approaches 0 according to the d-axis current deviation ΔId. To do. Similarly, the current feedback control unit 68 determines the q-axis voltage command value Vq_c by a feedback control law such as a PI control law so that the deviation ΔIq approaches 0 according to the q-axis current deviation ΔIq.

  When determining the d-axis voltage command value Vd_c and the q-axis voltage command value Vq_c, the d-axis voltage command value and the q-axis voltage command respectively obtained from the d-axis current deviation ΔId and the q-axis current deviation ΔIq by the feedback control law. The d-axis voltage command value Vd_c and the q-axis voltage command value Vq_c can be obtained by adding a non-interference component for canceling the influence of the speed electromotive force that interferes between the d-axis and the q-axis to the value. preferable.

  Further, the energization control unit 52 calculates dq from the d-axis voltage command value Vd_c and the q-axis voltage command value Vq_c determined by the current feedback control unit 67 and the detected angle θm_s of the output shaft 2 of the electric motor 1 by the resolver 43. A dq-3 phase conversion unit 68 for obtaining phase voltage command values Vu_c, Vv_c, Vw_c of each phase of U phase, V phase, and W phase by -3 phase conversion, and according to these phase voltage command values Vu_c, Vv_c, Vw_c In addition, the armature winding of each phase of the electric motor 1 is provided with a PWM control unit 69 that energizes via an inverter circuit (not shown) by PWM control. In this case, the PWM control unit 69 energizes the armature windings of each phase by controlling ON / OFF of each switching element of the inverter circuit. In the dq-3 phase conversion, a set of the d-axis voltage command value Vd_c and the q-axis voltage command value Vq_c is converted into a conversion matrix corresponding to the detected angle value θm_s (more specifically, the rotation angle of the output shaft 2 in electrical angle). Is a process of converting into a set of phase voltage command values Vu_c, Vv_c, Vw_c.

  With the function of the energization control unit 52 described above, the output of the electric motor 1 while preventing the combined voltage of the d-axis voltage and the q-axis voltage from exceeding the target value (radius of the voltage circle) corresponding to the power supply voltage Vdc. The d-axis voltage command value Vd_c and the q-axis voltage command value Vq_c are set so that the torque generated on the shaft 2 (the output torque of the electric motor 1) follows the torque command value Tr_c (so that ΔId and ΔIq converge to 0). A set is determined. Then, in accordance with the d-axis voltage command value Vd_c and the q-axis voltage command value Vq_c, the energization current of each phase armature winding of the electric motor 1 is controlled.

  In addition to the rotation angle calculation unit 51 and the energization control unit 52, the control device 50 includes a Ke estimation unit 53 that calculates the induced voltage constant estimated value Ke_s, and an induced voltage constant command value that is a target value of the induced voltage constant of the electric motor 1. A Ke command calculation unit 54 that determines Ke_c, and a phase difference control unit 55 that controls the phase difference change driving unit 10 so as to make the induced voltage constant estimated value Ke_s coincide with the induced voltage constant command value Ke_s.

  In the present embodiment, the induced voltage constant Ke is used as the “characteristic parameter” in the present invention. Therefore, the induced voltage constant command value Ke_c determined by the Ke command calculation unit 54 corresponds to the target value of the characteristic parameter in the present invention. The induced voltage constant estimated value Ke_e obtained by the Ke estimating unit 53 corresponds to the estimated value of the characteristic parameter in the present invention. Then, the Ke command calculation unit 54 and the phase difference control unit 55 realize the inter-rotor phase difference control means in the present invention, and the Ke estimation unit 53 realizes the characteristic parameter estimation means in the present invention.

  The torque command value Tr_c, the speed detection value Nm_s, and the value of the power supply voltage Vdc of the electric motor 1 are sequentially input to the Ke command calculation unit 54. Then, the Ke command calculation unit 54 sequentially determines the induced voltage constant command value Ke_c of the electric motor 1 according to a map set in advance from these input values Tr_c, Nm, and Vdc.

  In this case, for example, when the actual induced voltage constant of the electric motor 1 coincides with the induced voltage constant command value Ke_c determined by the map, the map shows the torque command value Tr_c, the speed detection value Nm_s, and the power supply voltage. While the magnitude of the combined voltage (vector sum) of the d-axis voltage and the q-axis voltage of the electric motor 1 falls within a voltage circle corresponding to the power supply voltage Vdc with respect to the pair with the value of Vdc, It is set so that energy efficiency (ratio of output energy to input energy) can be increased as much as possible.

  Here, in general, the smaller the induced voltage constant (in other words, the greater the inter-rotor phase difference θd), the more the output shaft 2 of the motor 1 can be rotated in a higher speed range. The region where the energy efficiency of the electric motor 1 is high can be shifted to the high speed rotation side. Further, the output torque of the electric motor 1 can be increased as the induced voltage constant is increased (in other words, the rotor phase difference θd is decreased). Accordingly, the induced voltage constant command value Ke_c may be set in consideration of the characteristics of the electric motor 1 as described above and the operation mode required of the electric motor 1, and various setting methods are possible.

  In the present embodiment, when the speed command value Nm_s and the power supply voltage Vdc are constant in the Ke command calculation unit 54, the induced voltage constant command value Ke_c is basically the absolute value of the torque command value Tr_c | It is set so that the value of Ke_c increases as Tr_c | increases.

  Further, when the torque command value Tr_c and the power supply voltage Vdc are constant, the induced voltage constant command value Ke_c is basically a region where the speed detection value Nm_s is high, and the speed detection value Nm_s is large. The value of Ke_c is set so as to decrease. When the torque command value Tr_c and the speed detection value Nm_s are constant, the induced voltage constant command value Ke_c is basically set such that the value of Ke_c decreases as the value of the power supply voltage Vdc decreases. The

  Supplementally, when setting the induced voltage constant command value Ke_c, it may be set in consideration of a request for preventing overheating of the electric motor 1.

  The Ke estimation unit 53 includes a q-axis voltage command value Vq_c determined by the current feedback control unit 67 as a plurality of predetermined types of state quantities of the electric motor 1 used for estimating the induced voltage constant Ke, and the 3 The d-axis current detection value Id_s and the q-axis current detection value Iq_s obtained by the phase-dq conversion unit 61, the speed detection value Nm_s obtained by the rotational speed calculation unit 51, and the Ke command calculation unit 54 are determined. The induced voltage constant command value Ke_c and the torque command value Tr_c are sequentially input. Then, the Ke estimating unit 53 obtains an induced voltage constant estimated value Ke_e from these input values Vq_c, Id_s, Iq_s, Nm_s, Ke_c, and Tr_c.

  Here, when there is no iron loss of the electric motor 1, the following is generally between the d-axis voltage Vd, the q-axis voltage Vq, the d-axis current Id, the q-axis current Iq, and the induced voltage constant Ke of the electric motor 1. The following relational expression (1) holds. Is the rotational angular velocity at the electrical angle of the output shaft 2 of the electric motor 1, R is the resistance of the armature winding, and Ld is the inductance of the d-axis armature.

Ke ・ ω + R ・ Iq = Vq−ω ・ Ld ・ Id (1)

Therefore, when there is no iron loss of the electric motor 1, the induced voltage constant Ke can be accurately estimated by the following equation (2) obtained by modifying the above equation (1).

Ke = (Vq−ω · Ld · Id−R · Iq) / ω (2)

On the other hand, the iron loss of the electric motor 1 consists of hysteresis loss and eddy current loss. The hysteresis loss is proportional to the rotational frequency of the output shaft 2 of the electric motor 1, and the eddy current loss is proportional to the square of the rotational frequency of the output shaft 2 of the electric motor 1. For this reason, the total iron loss of these hysteresis loss and eddy current loss changes according to the rotational speed of the output shaft 2 of the electric motor 1.

  The graph of FIG. 5 is a graph illustrating the relationship between the rotational speed and iron loss. As shown in the figure, the iron loss of the electric motor 1 increases rapidly in a high speed range where the rotation speed of the output shaft 2 is relatively high. The three graphs shown in FIG. 5 are different from each other in the actual induced voltage constant Ke of the electric motor 1.

  Since the relational expression of the expression (1) does not consider the influence of the iron loss of the motor 1, the induced voltage calculated by the expression (2) in a state where the iron loss of the motor 1 is relatively large. An error in the value of the constant Ke increases. Therefore, in this embodiment, the value of the induced voltage constant Ke calculated by the calculation of Expression (2) is used as the basic estimated value of the induced voltage constant Ke, and the estimated error due to iron loss is reduced to this basic estimated value. The induced voltage constant estimated value Ke_e is obtained by performing correction for the purpose.

  FIG. 6 is a block diagram illustrating processing functions of the Ke estimation unit 53 in the present embodiment. As shown in the figure, the Ke estimating unit 53 corrects the basic estimated value Ke_eb and the Ke basic estimated value calculating unit 53a that calculates the basic estimated value Ke_eb of the induced voltage constant Ke by the calculation of the right side of the equation (2). And a Ke correction unit 53b. In this embodiment, the Ke correction unit 53b adds a correction value Ke to the basic estimation value Ke_eb, and a Ke correction value calculation unit 53c that calculates a correction value ΔKe for correcting the basic estimation value Ke_eb. The correction calculation unit 53d corrects the basic estimated value Ke_eb.

  The Ke basic estimated value calculator 53a corresponds to the basic estimated value calculator in the present invention, and the Ke corrector 53b corresponds to the corrector in the present invention.

  In this case, the Ke basic estimated value calculation unit 53a includes a plurality of state quantity values (Vq_c, Id_s, Iq_s, Nm_s, Ke_c, Tr_c) of the electric motor 1 input to the Ke estimating unit 53. As the value of the state quantity necessary for the calculation of the right side, the q-axis voltage command value Vq_c as an observed value of the armature winding voltage, and the d-axis current detection values Id_s and q as the observed values of the armature winding current A shaft current detection value Iq_s and a speed detection value Nm_s as an observed value of the rotation speed of the output shaft 2 are acquired. Then, the Ke basic estimated value calculation unit 53a uses the input Vd_c, Id_s, and Iq_s as the values of Vd, Id, and Iq on the right side of the equation (2), respectively, and the electrical angular velocity (Nm_s) corresponding to the input Nm_s. The value obtained by multiplying the number of pole pairs of the electric motor 1 by the value of ω on the right side of Equation (2) is used to calculate the right side of Equation (2). Thereby, the Ke basic estimated value calculation unit 53a calculates the basic estimated value Ke_eb of the induced voltage constant estimated value Ke_e.

  In the present embodiment, predetermined values (fixed values) are used as the values of R and Ld on the right side of Expression (2). However, the value of R may be estimated from the sampling value of the U-phase current detection value Iu_s or the W-phase current detection value Iw_s, for example. Further, the value of Ld may be variably set from a d-axis current command value Id_c according to a predetermined table or the like.

  Further, the Ke correction value calculation unit 53c of the Ke correction unit 53b receives the rotation speed of the output shaft 2 as the value of the state quantity of the electric motor 1 having a correlation with the iron loss of the electric motor 1 in order to obtain the correction value ΔKe. The speed detection value Nm_s as the observed value, the induced voltage constant command value Ke_c as the target value of the induced voltage constant Ke, and the torque command value Tr_c as the target value of the output torque of the electric motor 1 are input.

  Here, as described above, the iron loss of the electric motor 1 not only changes in accordance with the rotation speed of the output shaft 2 of the electric motor 1 but also the stator 5 of the electric motor 1 (more specifically, the magnetism with the armature winding attached thereto). The core loss (both hysteresis loss and eddy current loss) increases as the maximum magnetic flux density increases. The maximum magnetic flux density is mainly affected by the strength of the composite field magnetic flux of the permanent magnets 6 and 8 of the rotors 3 and 4, and the strength of the composite field magnetic flux is approximately between the rotors. It changes according to the phase difference θd or according to the induced voltage constant Ke corresponding to the inter-rotor phase difference θd. In this case, the smaller the inter-rotor phase difference θd (the greater the induced voltage constant Ke of the electric motor 1), the greater the strength of the combined field magnetic flux, and the greater the maximum magnetic flux density. Therefore, as shown in the graph of FIG. 5, the iron loss of the electric motor 1 has a large induced voltage constant Ke of the electric motor 1 when the rotational speed (speed detection value Nm_s) of the output shaft 2 of the electric motor 1 is constant. (The smaller the inter-rotor phase difference θd), the larger it becomes.

  Further, the maximum magnetic flux density is also affected by magnetic flux generated by energization of the armature winding, and the strength of the magnetic flux is the output torque of the electric motor 1 or the armature winding for generating the output torque. It changes according to the current (especially the q-axis current) that flows through the capacitor. In this case, as the output torque of the electric motor 1 or the current passed through the armature winding to generate the output torque is increased, the maximum magnetic flux density, and thus the iron loss is increased.

  Therefore, in the present embodiment, the speed detection value Nm_s, the induced voltage constant command value Ke_c, and the torque command value Tr_c are used as the Ke correction value calculation unit as the state quantity of the motor 1 having a correlation with the iron loss of the motor 1. Input to 53c. The Ke correction value calculator 53c calculates the correction value ΔKe from the input values of these state quantities based on a preset map.

  FIGS. 7A and 7B are graphs typically illustrating the map. In the present embodiment, a plurality of types of values of the induced voltage constant command value Ke_c are determined in advance, and for each induced voltage constant command value Ke_c of each type of value, a set of a speed detection value Nm_s and a torque command value Tr_c, A map (two-dimensional map) that defines the relationship with the correction value ΔKe is prepared. FIGS. 7A and 7B exemplarily show maps when the induced voltage constant command value Ke_c is two kinds of values Ke_c1 and Ke_cn (Ke_c1> Ke_cn). In this case, in each map, the relationship between ΔKe and the set of Nm_s and Tr_c is such that the greater the speed detection value Nm_s and the greater the torque command value Tr_c, the greater the correction value ΔKe (> 0). Is set. These maps are set so that ΔKe increases as the value of the induced voltage constant command value Ke_c increases (the interrotor phase difference θd decreases) when the set of Nm_s and Tr_c is constant. .

  The Ke correction value calculator 53c calculates the correction value ΔKe from the input speed detection value Nm_s, the induced voltage constant command value Ke_c, and the torque command value Tr_c based on the map set as described above.

  The correction value ΔKe thus obtained by the Ke correction value calculation unit 53c and the basic estimation value Ke_eb calculated by the Ke basic estimation value calculation unit 53a are input to the correction calculation unit 53d. Then, the correction calculation unit 53d corrects the basic estimated value Ke_eb by adding the correction value ΔKe to the basic estimated value Ke_eb, thereby obtaining an induced voltage constant estimated value Ke_e (= Ke_eb + ΔKe).

  The processing of the Ke estimation unit 53 described above is sequentially executed, and the induced voltage constant estimated value Ke_e is sequentially obtained. In the present embodiment, the Ke correction value calculation unit 53c calculates the correction value ΔKe to be added to the basic estimated value Ke_eb. However, a correction value to be multiplied by the basic estimated value Ke_eb may be calculated.

  The induced voltage constant estimated value Ke_e obtained by the Ke estimating unit 53 as described above and the induced voltage constant command value Ke_c determined by the Ke command calculating unit 54 are sequentially input to the phase difference control unit 55. The

  The phase difference control unit 55 gives the induced voltage constant estimated value Ke_e between the rotors 3 and 4 from the phase difference change driving means 10 so as to match (converge) the induced voltage constant estimated value Ke_e with the induced voltage constant command value Ke_c. By sequentially generating an actuator operation command as an operation amount (control input) that defines the driving force (torque) and outputting the actuator operation command to the actuator 11 of the phase difference change drive unit 10, the phase difference change drive unit 10 operations are controlled. That is, the phase difference change drive means is applied so that the torque necessary to make the induced voltage constant estimated value Ke_e coincide with the induced voltage constant command value Ke_c is applied between the rotors 3 and 4 from the phase difference change drive means 10. 10 operations are controlled.

  In this case, the phase difference control unit 55 generates an actuator operation command as follows, for example. That is, the phase difference control unit 55 sequentially obtains a deviation between the induced voltage constant estimated value Ke_e and the induced voltage constant command value Ke_c, and generates an actuator operation command from the deviation by a feedback control law such as a PI law.

  Alternatively, the phase difference control unit 55 generates the induced voltage constant estimated value Ke_e and the induced voltage based on a map (or an arithmetic expression) representing the relationship between the induced voltage constant Ke and the rotor phase difference θd shown in FIG. The voltage constant command value Ke_c is converted into the estimated value of the inter-rotor phase difference θd and the command value of the inter-rotor phase difference θd, respectively. Then, the phase difference control unit 55 generates an actuator operation command from the deviation between the estimated value of the inter-rotor phase difference θd and the command value by a feedback control law such as a PI law.

  For example, the feedforward component of the actuator operation command determined according to the induced voltage constant estimated value Ke_e (or the estimated value of the rotor phase difference θd), the induced voltage constant estimated value Ke_e, and the induced voltage constant command value Ke_c. The actuator operation command may be determined by adding the feedback component determined by the feedback control law according to the deviation (or the deviation between the estimated value of the inter-rotor phase difference θd and the command value).

  By the processing of the phase difference control unit 55 described above, the induced voltage constant estimated value Ke_e is matched with the induced voltage constant command value Ke_c, or the estimated value of the inter-rotor phase difference θd corresponding to Ke_e corresponds to Ke_c. Actuator operation commands are sequentially generated so as to match the command value of the rotor phase difference θd. The driving force (torque) applied between the rotors 3 and 4 from the phase difference change driving means 10 is controlled in accordance with the actuator operation command.

  In this case, since the induced voltage constant estimated value Ke_e is calculated so as to reduce an error caused by the iron loss of the electric motor 1, accuracy as an estimated value of the actual induced voltage constant Ke is high. Therefore, the inter-rotor phase difference θd can be controlled to a phase difference such that the actual induced voltage constant Ke of the electric motor 1 accurately matches the induced voltage constant command value Ke_c.

  Thus, since the rotor phase difference θd can be accurately controlled to a desired phase difference (a phase difference in which the actual induced voltage constant Ke becomes the induced voltage constant command value Ke_c), the motor 1 can be operated efficiently. In addition, the output torque of the electric motor 1 can be appropriately controlled to the target torque command value Tr_c by the energization control by the energization control unit 52 described above.

  In the embodiment described above, the induced voltage constant Ke is used as the characteristic parameter in the present invention. However, the inter-rotor phase difference θd may be used as the characteristic parameter in the present invention. In this case, the target value of the rotor phase difference θd is sequentially set based on, for example, a map from the power supply voltage Vdc of the electric motor 1, the torque command value Tr_c, and the speed detection value Nm_s, or the Ke command calculation is performed. The target value of the inter-rotor phase difference θd corresponding to the induced voltage constant command value Ke_c obtained by the unit 54 may be set based on the data table representing the relationship shown in the graph of FIG. Further, the estimated value of the inter-rotor phase difference θd can be obtained, for example, from the induced voltage constant estimated value Ke_e obtained by the Ke estimating unit 53 based on a data table representing the relationship shown in the graph of FIG. Good. Alternatively, the basic estimated value of the rotor phase difference θd obtained from the basic estimated value Ke_eb of the induced voltage constant Ke based on the data table representing the relationship shown in the graph of FIG. 3 can be obtained as the speed detection value Nm_s and the induced voltage. By correcting the constant command value Ke_c (or the target value of the inter-rotor phase difference θd) and the torque command value Tr_c with the correction value obtained using the map in the same manner as the Ke correction value calculation unit 53c, An estimated value of the phase difference θd may be obtained.

  In the embodiment, when the calculation of the right side of the equation (2) is performed to obtain the basic estimated value Ke_eb of the induced voltage constant Ke, the q-axis voltage command value Vq_c, the d-axis current detection value Id_s, and the q-axis Although the current detection value Iq_s is used, for example, when the voltage of the armature winding of each phase is detected, the detection value (observation value) of the q-axis voltage obtained from the detection value is used instead of Vq_c. You may use for. Further, instead of the d-axis current detection value Id_s, a target value of the d-axis current (Id_c + ΔIda in the present embodiment) may be used. Further, instead of the q-axis current detection value Iq_s, a target value of q-axis current (Iq_c + ΔIqa in the present embodiment) may be used.

  Further, the equation (1) is converted into a relational expression including each phase current and phase voltage, or a so-called α-β coordinate system as a stationary coordinate system fixed to the stator 5 of the electric motor 1. The basic estimated value Ke_eb of the induced voltage constant Ke (or the basic estimated value of the inter-rotor phase difference θd corresponding to Ke_eb) may be obtained on the basis of an expression converted into a relational expression including voltage and current at Good. In that case, a state quantity necessary for obtaining the basic estimated value may be determined according to the variable included in the equation.

  In the embodiment, in order to correct the basic estimated value Ke_eb of the induced voltage constant Ke (or the basic estimated value of the inter-rotor phase difference θd), the state quantity having a correlation with the iron loss of the motor 1 is used as the state quantity. The speed detection value Nm_s, the induced voltage constant command value Ke_c, and the torque command value Tr_c were used, but the state quantity for correcting the basic estimated value of the induced voltage constant Ke and the inter-rotor phase difference θd (correlation with iron loss) (Hereinafter referred to as a basic estimated value correcting state quantity) is not limited to this. For example, when both rotors 3 and 4 are non-salient pole type rotors as in the above embodiment, No. 1 in the following Table 1 is used. Combination patterns of basic estimated value correcting state quantities as shown in 1 to 6 can be used.

  In this case, no. In the combination pattern 1, the target value of the induced voltage constant (the induced voltage constant command value Ke_c) or the target value of the inter-rotor phase difference θd and the observed value of the rotational speed of the output shaft 2 of the motor 1 (the speed detection). Two state quantities with the value Nm_s) are used as basic estimated value correcting state quantities.

  No. In the combination pattern of No. 2, no. Of the state quantities of one combination pattern, the observed value of the d-axis current (the detected q-axis current value Id_s) is used as the basic estimated value correcting state quantity instead of the observed value of the rotational speed.

  No. In the combination pattern 3, the target value of the induced voltage constant (the induced voltage constant command value Ke_c) or the target value of the inter-rotor phase difference θd and the observed value of the rotational speed of the output shaft 2 of the motor 1 (the speed detection). The three state quantities of the value Nm_s) and the target value of the output torque of the electric motor 1 (the torque command value Tr_c) are used as basic estimated value correcting state quantities. This No. The combination pattern 3 corresponds to the combination pattern of the embodiment.

  No. In the combination pattern No. 4, no. Of the three combination pattern state quantities, instead of the observed rotational speed value, the d-axis current observation value (the d-axis current detection value Id_s) or the target value (Idc + ΔIda in the embodiment) is a basic estimated value. Used as a correction state quantity.

  No. In the combination pattern of No. 5, no. Of the three combination pattern state quantities, instead of the target value of the output torque, the observed value of the q-axis current (the q-axis current detection value Iq_s) or the target value (Iqc + ΔIqa in the embodiment) is a basic estimated value. Used as a correction state quantity.

  No. In the combination pattern No. 6, no. Of the three combination pattern state quantities, instead of the observed rotational speed value, the d-axis current observation value (the d-axis current detection value Id_s) or the target value (Idc + ΔIda in the embodiment) is a basic estimated value. In addition to the target value of the output torque, the observed value of the q-axis current (the q-axis current detection value Iq_s) or the target value (Iqc + ΔIqa in the above embodiment) is used as the basic estimated value correction state. Used as a quantity.

  In appropriately estimating the induced voltage constant Ke or the phase difference θd between the rotors, as shown in Table 1, at least one of the target value of the induced voltage constant Ke and the target value of the phase difference θd between the rotors The two state quantities of the observed value of the rotational speed of the output shaft 2 of the electric motor 1 and either the observed value or the target value of the d-axis current may be used as the basic estimated value correcting state quantity. In order to further improve the estimation accuracy of the induced voltage constant Ke or the phase difference θd between the rotors, in addition to the above two state quantities, the target value of the output torque of the motor 1, the observed value or the target value of the q-axis current, It is preferable to use any one of them as a basic estimated value correcting state quantity.

  Supplementally, when the rotors 3 and 4 are salient pole type rotors, generally, the correlation between the rotational speed of the output shaft of the motor and the d-axis current is lost. For this reason, when both rotors 3 and 4 are salient pole type rotors, No. 1 in Table 1 is used. It is preferable to use the state quantity in the combination pattern of 1, 3, 5 as the basic estimated value correction state quantity.

The figure which looked at the important section of the electric motor in one embodiment of the present invention in the axial center direction of the electric motor. 2A shows a phase relationship between the inner rotor and the outer rotor in the maximum field state, and FIG. 2B shows a phase relationship between the inner rotor 4 and the outer rotor 3 in the field minimum state. Figure. The graph which illustrates the relationship between the induced voltage constant of the electric motor of an embodiment, and the phase difference between rotors. The block diagram which shows the functional structure of the control apparatus which performs operation | movement control of the electric motor and phase difference change drive means of embodiment. The graph which illustrates the relationship between the rotational speed of the electric motor of an embodiment, and an iron loss. The block which shows the processing function of Ke estimation part shown in FIG. The graph which illustrates typically the map used by the process of the Ke correction value calculating part shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electric motor, 2 ... Output shaft, 3 ... Outer rotor, 4 ... Inner rotor, 6, 8 ... Permanent magnet, 10 ... Phase difference change drive means, 50 ... Control apparatus, 52 ... Current supply control part (energization control means), 53... Ke estimation unit (characteristic parameter estimation unit), 54... Ke command calculation unit (rotor phase difference control unit), 55... Phase difference control unit (rotor phase difference control unit), 53 a. (Basic estimated value calculation means), 53b... Ke correction section 53b (correction means).

Claims (4)

A first rotor and a second rotor, each having a permanent magnet for generating a field magnetic flux, and an output shaft rotatable integrally with the first rotor of the two rotors are coaxially provided, and the second rotor includes the A phase difference change drive that changes the phase difference between the two rotors by applying a driving force between the two motors and a motor that is provided to be relatively rotatable with respect to the first rotor. An estimated voltage constant of the motor as a characteristic parameter of the motor or an actual value of a phase difference between the rotors, and using the estimated value of the characteristic parameter, the motor system A control device for controlling the operation of
Obtaining a target value or an observed value of each of a plurality of predetermined state quantities of the motor including a state quantity having a correlation with the iron loss of the motor, and based on the obtained values of the plurality of state quantities, A characteristic parameter estimating means for obtaining an estimated value of the characteristic parameter ;
Energization control means for setting a target value of the current of the armature winding of the motor and controlling the current of the armature winding so as to match the observed value of the current with the target value;
An inter-rotor phase difference control means for setting the target value of the characteristic parameter and controlling the phase difference change driving means so as to match the estimated value of the characteristic parameter with the target value;
As the values of the plurality of state quantities acquired by the characteristic parameter estimation means, at least a target value or an observed value of the armature winding voltage of the motor, and a target value or an observed value of the current of the armature winding, The observed value of the rotation speed of the output shaft of the motor, and the target value of the characteristic parameter are included,
The characteristic parameter estimation means includes a target value or observation value of the voltage of the armature winding of the motor, a target value or observation value of the current of the armature winding, and an observation value of the rotation speed of the output shaft of the motor. A basic estimated value calculating means for obtaining a basic estimated value of the characteristic parameter based on a predetermined relationship established between the voltage, current and rotational speed and the characteristic parameter when there is no iron loss of the motor;
At least the target value of the characteristic parameter and the observed value of the rotation speed of the output shaft of the motor are used as the value of the state quantity having a correlation with the iron loss, and depending on the value of the state quantity having a correlation with the iron loss. And a correction means for determining the estimated value of the characteristic parameter by correcting the basic estimated value . A first rotor and a second rotor, each having a permanent magnet for generating a field magnetic flux, and an output shaft rotatable integrally with the first rotor of the two rotors are coaxially provided, and the second rotor includes the A phase difference change drive that changes the phase difference between the two rotors by applying a driving force between the two motors and a motor that is provided to be relatively rotatable with respect to the first rotor. An estimated voltage constant of the motor as a characteristic parameter of the motor or an actual value of a phase difference between the rotors, and using the estimated value of the characteristic parameter, the motor system A control device for controlling the operation of
Obtaining a target value or an observed value of each of a plurality of predetermined state quantities of the motor including a state quantity having a correlation with the iron loss of the motor, and based on the obtained values of the plurality of state quantities, A characteristic parameter estimating means for obtaining an estimated value of the characteristic parameter ;
Energization control means for setting a target value of the current of the armature winding of the motor and controlling the current of the armature winding so as to match the observed value of the current with the target value;
An inter-rotor phase difference control means for setting the target value of the characteristic parameter and controlling the phase difference change driving means so as to match the estimated value of the characteristic parameter with the target value;
Both rotors of the motor are non-salient rotors,
As the values of the plurality of state quantities acquired by the characteristic parameter estimation means, at least a target value or an observed value of the armature winding voltage of the motor, and a target value or an observed value of the current of the armature winding, The observed value of the rotational speed of the output shaft of the motor and the target value of the characteristic parameter are included, and the target value or the observed value of the current of the armature winding is determined by the permanent magnets of the two rotors. The target value or observed value of the d-axis current, which is the current component in the d-axis direction in the dq coordinate system, where the direction of the generated field magnetic flux is the d-axis and the direction orthogonal to the d-axis is the q-axis is included. And
The characteristic parameter estimation means includes a target value or observation value of the voltage of the armature winding of the motor, a target value or observation value of the current of the armature winding, and an observation value of the rotation speed of the output shaft of the motor. A basic estimated value calculating means for obtaining a basic estimated value of the characteristic parameter based on a predetermined relationship established between the voltage, current and rotational speed and the characteristic parameter when there is no iron loss of the motor; The target value of the characteristic parameter and the target value or the observed value of the d-axis current are used as the value of the state quantity having a correlation with the iron loss, and according to the value of the state quantity having a correlation with the iron loss, A control device for an electric motor system comprising correction means for obtaining an estimated value of the characteristic parameter by correcting the basic estimated value . In the control apparatus of the electric motor system according to claim 1 or 2 ,
The value of the plurality of state quantities acquired by the characteristic parameter estimation means further includes a target value of the output torque of the electric motor,
The correction means further uses a target value of the output torque of the electric motor as a value of a state quantity having a correlation with the iron loss in order to correct the basic estimated value. . In the control apparatus of the electric motor system according to claim 1 or 2 ,
The target value or observed value of the current of the armature winding includes a target value or observed value of the q-axis current that is a current component in the q-axis direction in the dq coordinate system,
The correction means further uses a target value or an observed value of the q-axis current as a value of a state quantity having a correlation with the iron loss in order to correct the basic estimated value. Control device.