JP2008067516A - Electric motor control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform energization control of an armature, having a stator of a motor so as to match the direction of the combined field of the permanent magnet of both rotors in the motor, capable of changing the phase difference between the two rotors. <P>SOLUTION: The motor 3 has two rotors 10, 11 having permanent magnets 13, 14, respectively, and the phase difference between both the rotors 10, 11 is changeable. One rotational angle of the rotors 10, 11, for example, the rotational angle θm of the rotor 10, is detected by a rotation angle detection means 43. The detected rotational angle θm is corrected by a rotation angle correction means 51. By using the rotational angle θm' after the correction, the energization control of the armature of the motor 3 is performed by an energization control means 53. The rotational angle correction means 51 corrects the detection value of the rotational angle θm, according to the parameter θd_c that represents the phase difference between both the rotors 10, 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a control device for an electric motor having two rotors each generating a field by a permanent magnet and capable of changing a phase difference between the two rotors.

  In a permanent magnet type electric motor, an electric motor having a double rotor structure that includes a permanent magnet that generates a magnetic field in each of two coaxially arranged rotors has been known (see, for example, Patent Document 1). . In this type of electric motor, the two rotors can rotate relative to each other about their axis, and the phase difference between the two rotors can be changed by the relative rotation. Then, by changing the phase difference between the two rotors, it is possible to change the strength (magnitude of magnetic flux) of the combined field formed by combining the fields generated by the permanent magnets of each rotor.

In the electric motor found in Patent Document 1, the phase difference between the two rotors mechanically changes in accordance with the rotational speed of the electric motor. That is, both rotors are connected via a member that is displaced in the radial direction of the electric motor by the action of centrifugal force. One of the rotors is rotatable integrally with an output shaft that outputs the generated torque of the electric motor to the outside. And the other rotor rotates relatively with respect to one rotor which can rotate integrally with an output shaft with the displacement of the said member, and it is comprised so that the phase difference between both rotors may change. In this case, when the motor is in a stopped state, the directions of the magnetic poles (directions of the magnetic flux) of the permanent magnets provided in both rotors are the same, and the strength of the combined field of these permanent magnets is maximized. The permanent magnet of each rotor is arranged so that it may become. Then, as the rotational speed of the electric motor increases, the phase difference between the rotors changes due to the centrifugal force, and the strength of the combined field of the permanent magnets of the rotors decreases.
JP 2002-204541 A

  By the way, in order to appropriately perform a desired operation of the permanent magnet type electric motor, the energization current of the armature provided in the stator of the electric motor is determined by the rotation angle of the rotor (more generally, the permanent magnet provided in the rotor). It is necessary to control according to the direction of the field. For this reason, in an electric motor having a single rotor, the rotation angle of the rotor (= rotational speed of the output shaft of the electric motor) is detected by a detector such as a resolver, and the energization current of the armature is controlled according to the detected value. It is generally done.

  Therefore, in an electric motor having two rotors as found in Patent Document 1, for example, an output shaft of the electric motor or a rotation angle of a rotor that can rotate integrally with the output shaft (the output shaft is a predetermined amount with respect to the stator). It is conceivable to detect a rotation angle based on a position stopped in a positional relationship, and to control the energization current of the armature according to the detected value.

  However, in an electric motor having two rotors as seen in Patent Document 1, a permanent magnet provided in one rotor and a permanent magnet provided in the other rotor according to a change in the phase difference between the two rotors. The relative positional relationship changes. For this reason, the direction of the synthetic field of the permanent magnets of both rotors changes depending not only on the rotation angle of the output shaft of the motor but also on the phase difference between the rotors.

  For this reason, even if the rotation angle of the output shaft of the electric motor is detected, the detected value of the rotation angle may deviate from the direction of the combined field of the permanent magnets of both rotors. As a result, even if the detected value of the rotation angle is used as it is and the energization current of the armature of the motor is controlled, the operating efficiency of the motor is reduced, and the output torque of the motor deviates from the target torque. Inconveniences such as occurrence or vibration of output torque may occur.

  The present invention has been made in view of such a background, and in an electric motor capable of changing the phase difference between two rotors, the electric motor is provided with a stator of the electric motor so as to match the direction of the composite field of the permanent magnets of both rotors. Another object of the present invention is to provide a control device that can perform energization control of an armature.

  In order to achieve this object, the motor control device of the present invention has a first rotor and a second rotor that generate a magnetic field by permanent magnets, and an output that can rotate integrally with the first rotor of the two rotors. The second rotor is provided so as to be rotatable relative to the first rotor, and the phase difference between the two rotors is changed by the relative rotation of the second rotor. A control device for an electric motor capable of changing the strength of a synthetic field formed by synthesizing a field of a permanent magnet, and an angle detection means for detecting a rotation angle of one of the rotors And a rotation angle correcting means for acquiring a parameter value representing an actual phase difference between the two rotors and correcting the detected rotation angle in accordance with the acquired parameter value, and the correction Characterized in that a current supply control means for controlling the energization current of the armature with the stator of the electric motor in accordance with the rotation angle (the first invention).

  According to the first aspect of the present invention, the rotation angle of the one rotor detected by the angle detection means (the rotation angle in the coordinate system fixed to the stator of the electric motor) is set to the actual position between the rotors. By correcting according to the value of the parameter representing the phase difference, it is possible to obtain a rotation angle that can specify the direction of the composite field in any phase difference between the rotors. Then, by controlling the energization current of the armature according to the corrected rotation angle, the energization of the armature included in the stator of the motor is matched to the direction of the composite field of the permanent magnets of both rotors. Control can be performed. As a result, it is possible to appropriately generate a desired output torque in the electric motor while suppressing a decrease in the operation efficiency of the electric motor and vibration of the output torque.

  The parameter includes a detected value or an estimated value of the phase difference between the rotors, or a state quantity having a certain correlation with the phase difference between the rotors (for example, an induced voltage constant of the motor, between the rotors). State quantity showing a monotonous change with respect to the change in phase difference). The parameter only needs to be able to specify (may be approximate specification) the actual phase difference between the two rotors from the value.

  In the first aspect of the invention, the rotation angle correction unit stores, for example, correlation data representing a correlation between the parameter value and the rotation angle correction amount in advance, and the correlation value is calculated from the acquired parameter value. The detected rotation angle is corrected according to the correction amount obtained based on the data (second invention).

  According to the second aspect of the invention, the rotation angle correction process by the rotation angle correction means can be easily performed. As the correlation data, a map or the like may be used, but an approximate expression that approximates the correlation may be used.

  In the second aspect of the invention, the rotation angle correction means includes means for performing a filtering process on the correction amount obtained based on the correlation data, and the detected rotation angle is determined according to the correction amount after the filtering process. It is preferable to correct (third invention).

  According to the third aspect of the present invention, it is possible to suppress the correction amount of the rotation angle from fluctuating excessively frequently and to stabilize the corrected rotation angle.

  In the second or third aspect of the invention, the value of the parameter corresponding to the phase difference between the two rotors where the strength of the combined field becomes maximum is set as the maximum field parameter value, and the strength of the combined field is increased. When the value of the parameter corresponding to the phase difference between the two rotors having a minimum value is the minimum field parameter value, the correlation is specifically the correction amount according to the change in the parameter value. Is a correlation in which the waveform of the change becomes a convex waveform with a predetermined value between the maximum field parameter value and the minimum field parameter value, and the correction value is an extreme value (fourth invention). ).

  That is, when the phase difference between the rotors is maintained at a phase difference corresponding to the maximum field parameter value, for example, when the direction of the composite field is a reference direction, The amount of deviation of the direction of the composite field from the reference direction is generally determined from the phase difference between the rotors corresponding to the maximum field parameter value (hereinafter referred to as the maximum field phase difference). When the phase difference corresponding to the minimum field parameter value (hereinafter referred to as the minimum field phase difference) is changed, a predetermined phase difference between the maximum field phase difference and the minimum field phase difference is obtained. The deviation amount is maximized. Therefore, by setting the correlation to a convex waveform correlation as described above, the correction amount of the rotation angle can be appropriately determined using the correlation data representing the correlation. . As a result, by correcting the rotation angle by the correction amount, a highly reliable rotation angle can be obtained as representing the direction of the synthetic field.

  An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing the main part of the internal configuration of the motor 3 in the axial direction of the motor 3, and FIG. 2 is a skeleton diagram showing a drive mechanism for changing the phase difference between the two rotors of the motor 3. is there. In FIG. 1, illustration of the drive mechanism is omitted.

  Referring to FIG. 1, electric motor 3 is a DC brushless motor having a double rotor structure, and includes an outer rotor 10 as a first rotor and an inner rotor 11 as a second rotor coaxially with output shaft 3a. Outside the outer rotor 10, there is a stator 12 fixed to a housing (not shown) of the electric motor 3, and an armature (an armature for three phases) not shown is mounted on the stator 12. .

  The outer rotor 10 is formed in an annular shape and includes a plurality of permanent magnets 13 arranged at substantially equal intervals in the circumferential direction. The permanent magnet 13 is formed in a long rectangular plate shape, and in a state where the longitudinal direction is directed to the axial direction of the outer rotor 10 and the normal direction is directed to the radial direction of the outer rotor 10, Embedded in the rotor 10.

  The inner rotor 11 is also formed in an annular shape. The inner rotor 11 is disposed coaxially with the outer rotor 10 on the inner side of the outer rotor 10 with the outer peripheral surface thereof being in sliding contact with the inner peripheral surface of the outer rotor 10. A slight clearance may be provided between the outer peripheral surface of the inner rotor 11 and the inner peripheral surface of the outer rotor 10. Further, the output shaft 3 a passes through the axial center portion of the inner rotor 11 coaxially with the inner rotor 11 and the outer rotor 10.

  Further, the inner rotor 11 includes a plurality of permanent magnets 14 arranged at substantially equal intervals in the circumferential direction. The permanent magnet 14 has the same shape as the permanent magnet 13 of the outer rotor 10 and is embedded in the inner rotor 11 in the same form as that of the outer rotor 10. The number of permanent magnets 14 in the inner rotor 11 is the same as the number of permanent magnets 13 in the outer rotor 10.

  Here, in FIG. 1, the permanent magnet 13 a shown in white among the permanent magnets 13 of the outer rotor 10 and the dotted permanent magnet 13 b are opposite to each other in the direction of the magnetic poles in the radial direction of the outer rotor 10. It has become. For example, the permanent magnet 13a has an N pole on the outer side (outer peripheral surface side of the outer rotor 10) and an S pole on the inner side (inner peripheral surface side of the outer rotor 10), and the permanent magnet 13b has an outer side. This surface is the S pole and the inner surface is the N pole. Similarly, the permanent magnets 14a shown in white among the permanent magnets 14 of the inner rotor 11 and the permanent magnets 14b marked with dots are opposite to each other in the direction of the magnetic poles in the radial direction of the inner rotor 11. . For example, the permanent magnet 14a has an N-pole surface on the outer side (the outer peripheral surface side of the inner rotor 11) and an S-pole surface on the inner side (the inner peripheral surface side of the inner rotor 11). This surface is the S pole and the inner surface is the N pole.

  In the present embodiment, in the outer rotor 10, pairs of permanent magnets 13 a and 13 a adjacent to each other and pairs of permanent magnets 13 b and 13 b adjacent to each other are alternately arranged in the circumferential direction of the outer rotor 10. It is arranged. Similarly, in the inner rotor 11, pairs of permanent magnets 14 a and 14 a adjacent to each other and pairs of permanent magnets 14 b and 14 b adjacent to each other are alternately arranged in the circumferential direction of the inner rotor 11. .

  Referring to FIG. 2, outer rotor 10 is connected to output shaft 3 a so as to be rotatable integrally with output shaft 3 a of electric motor 3. The inner rotor 11 is provided to be rotatable relative to the outer rotor 10 and the output shaft 3a. By the relative rotation of the inner rotor 11, the phase difference with the outer rotor 10 can be changed. In the present embodiment, for example, a phase difference changing device 15 having a planetary gear mechanism 30 is used as phase difference changing drive means for causing the inner rotor 11 to rotate relative to each other (changing the phase difference between the rotors 10 and 11). Is provided.

  The planetary gear mechanism 30 of the phase difference changing device 15 is disposed in a hollow portion inside the inner rotor 11. In this embodiment, the planetary gear mechanism 30 is of a single pinion type, and is integrated with the inner rotor 11 and the first ring gear R1 fixed to the outer rotor 10 so as to be rotatable integrally with the outer rotor 10. A second ring gear R2 fixed to the inner rotor 11 so as to be rotatable is provided coaxially with the inner rotor 11 and the outer rotor 10. Both ring gears R1, R2 are arranged in the axial direction thereof. A common sun gear S is provided at the axial center of both the ring gears R1 and R2, and a sun gear shaft 33 integrally having the sun gear S is rotatably supported by a plurality of bearings 34.

  A plurality of first planetary gears 31 that mesh with the sun gear S and the first ring gear R1 are provided, and these first planetary gears 31 are rotatably held by the first carrier C1. In this case, the first carrier C1 can rotate around the axis of the sun gear S, and each first planetary gear 31 can revolve around the sun gear S by the rotation of the first carrier C1.

  Further, a plurality of second planetary gears 32 that mesh with the sun gear 33 and the second ring gear R2 are provided, and these second planetary gears 32 are rotatably held by the second carrier C2. In this case, the second carrier C2 is fixed to the stator 12 (or the housing) of the electric motor 3 and cannot rotate.

  The gear ratio between the first ring gear R1, the first planetary gear 31, and the sun gear S is the same as the gear ratio between the second ring gear R2, the second planetary gear 32, and the sun gear S.

  In the planetary gear mechanism 15 configured as described above, when the output shaft 3a of the electric motor 3 and the outer rotor 10 are rotated in a state where the first carrier C1 is held unrotatable, the rotation speed is the same as that in the same direction. The inner rotor 11 rotates together with the second ring gear R2. Therefore, the inner rotor 11 rotates integrally with the outer rotor 10. When the first carrier C1 is rotationally driven, the inner rotor 11 rotates relative to the outer rotor 10. As a result, the phase difference between the inner rotor 11 and the outer rotor 10 (hereinafter referred to as inter-rotor phase difference) changes.

  Therefore, the phase difference changing device 15 according to the present embodiment rotates the first carrier C1 of the planetary gear mechanism 30 by an actuator 25 (rotation driving force generation source) such as an electric motor or a hydraulic actuator, so that the phase difference between the rotors is achieved. To change. In this case, the actuator 25 is connected to the first carrier C1 via a drive shaft 35 provided so as to be rotatable integrally with the first carrier C1, and a rotational force ( Torque).

  The above is the mechanical configuration of the electric motor 3 and the phase difference changing device 15 for the electric motor 3 in the present embodiment.

  In this embodiment, the single pinion type planetary gear mechanism 30 is used. However, for example, a double pinion type planetary gear mechanism may be used. In the present embodiment, the output shaft 3a of the electric motor 3 and the outer rotor 10 are configured to rotate integrally. However, the output shaft 3a of the electric motor 3 and the inner rotor 11 are configured to rotate integrally. The outer rotor 10 may be configured to rotate relative to the output shaft 3 a and the inner rotor 11. Further, the configuration of the phase difference changing device 15 is not limited to the configuration described above. For example, a hydraulic chamber may be formed inside the inner rotor 11 by a vane rotor or the like, and the inner rotor 11 may be rotated relative to the outer rotor 10 by operating the pressure in the hydraulic chamber.

  By rotating the inner rotor 11 with respect to the outer rotor 10 and changing the phase difference between the rotors by the phase difference changing device 15, the field generated by the permanent magnets 14 a and 14 b of the inner rotor 11 and the outer rotor 10 are changed. The strength (the magnetic field strength of the composite field) of the composite field with the field generated by the permanent magnets 13a and 13b (the radial field toward the stator 12) changes. Hereinafter, a state where the strength of the combined field is maximum is referred to as a field maximum state, and a state where the strength of the combined field is minimum is referred to as a field minimum state. FIG. 3A is a diagram illustrating a phase relationship between the inner rotor 11 and the outer rotor 10 in the maximum field state, and FIG. 3B is a diagram illustrating the relationship between the inner rotor 11 and the outer rotor 10 in the field minimum state. It is a figure which shows a phase relationship.

  As shown in FIG. 3A, the field maximum state is a state in which the permanent magnets 14a and 14b of the inner rotor 11 and the permanent magnets 13a and 13b of the outer rotor 10 are opposite to each other. More specifically, in this field maximum state, the permanent magnet 14a of the inner rotor 11 faces the permanent magnet 13a of the outer rotor 10, and the permanent magnet 14b of the inner rotor 11 faces the permanent magnet 13b of the outer rotor 10. In this state, in the radial direction, the directions of the magnetic fluxes Q1 of the permanent magnets 14a and 14b of the inner rotor 11 and the directions of the magnetic fluxes Q2 of the permanent magnets 13a and 13b of the outer rotor 10 are the same. The strength of the combined magnetic flux Q3 of the magnetic fluxes Q1 and Q2 (the strength of the combined field) is maximized. In a state in which the operation of the electric motor 3 is stopped, the inner rotor 11 can rotate freely (a state in which no rotational force is applied from the actuator 25 to the first carrier C1 of the planetary gear mechanism 30). The phase difference is balanced by the phase difference in the field maximum state.

  Further, as shown in FIG. 3B, the minimum field state is a state in which the permanent magnets 14a and 14b of the inner rotor 11 and the permanent magnets 13a and 13b of the outer rotor 10 face each other. More specifically, in this field minimum state, the permanent magnet 14a of the inner rotor 11 faces the permanent magnet 13b of the outer rotor 10, and the permanent magnet 14b of the inner rotor 11 faces the permanent magnet 13a of the outer rotor 10. In this state, the direction of the magnetic flux Q1 of the permanent magnets 14a and 14b of the inner rotor 11 and the direction of the magnetic flux Q2 of the permanent magnets 13b and 13a of the outer rotor 10 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) is minimized.

  In this embodiment, the inter-rotor phase difference in the maximum field state is defined as 0 [deg], and the inter-rotor phase difference in the minimum field state is defined as 180 [deg]. The inter-rotor phase difference (minimum field phase difference) in the field minimum state is defined as 0 [deg], and the rotor phase difference (maximum field phase difference) in the field maximum state is defined as 180 [deg]. May be. More generally speaking, the zero point of the phase difference between the rotors may be set arbitrarily.

  FIG. 4 shows an electric machine of the stator 12 when the output shaft 3a of the motor 3 is operated at a predetermined rotational speed in the maximum field state, the minimum field state, and the intermediate field state. It is the graph which compared the induced voltage induced by a child. The vertical axis and the horizontal axis of this graph are the induced voltage [V] and the rotation angle [degree] of the output shaft 3a in electrical angle, respectively. The graph with the reference symbol a is a graph in the maximum field state (the phase difference between the rotors = 0 [deg]), and the graph with the reference symbol b is the minimum field state (the phase difference between the rotors). = 180 [deg] state). Also, a graph with reference symbol c is a graph in these intermediate field states (a state in which the phase difference between the rotors is an intermediate value between 0 [deg] and 180 [deg]). It is. As can be seen from FIG. 4, the level of the induced voltage (amplitude level) can be changed by changing the inter-rotor phase difference between 0 [deg] and 180 [deg]. When the phase difference between the rotors is increased to 0 [deg] and 180 [deg], basically, the strength of the synthetic field decreases, and the induced voltage level decreases accordingly. I will do it.

  Thus, the induced voltage constant of the electric motor 3 can be changed by changing the phase difference between the rotors to increase or decrease the field strength. The induced voltage constant is a proportionality constant that defines the relationship between the angular velocity of the output shaft 3a of the electric motor 3 and the level of the induced voltage generated in the armature according to the angular velocity (effective value of the induced voltage). FIG. 5 is a graph showing the relationship between the induced voltage constant and the inter-rotor phase difference. As shown in the drawing, the value of the induced voltage constant decreases as the phase difference between the rotors increases (the strength of the combined field decreases).

  Referring to FIG. 4, the waveform of graph a when the inter-rotor phase difference is 0 [deg] and the waveform of graph b when 180 [deg] are substantially synchronized ( The rotation angles at which the induced voltage level becomes 0 are substantially the same). This is because the direction of the composite field (the direction of the magnetic flux of the composite field) is almost the same when the phase difference between the rotors is 0 [deg] and when it is 180 [deg]. . On the other hand, the waveform of the graph c when the phase difference between the rotors is an intermediate value between 0 [deg] and 180 [deg] causes a phase shift with respect to the waveforms of the graphs a and b (induced voltage). The rotation angle at which the level of 0 is different between the graph c and the graph a or c). This is because the inter-rotor phase difference is 0 [deg] or 180 [deg] when the inter-rotor phase difference is an intermediate value between 0 [deg] and 180 [deg]. This is because the direction of the synthetic field is shifted in the circumferential direction of the rotors 10 and 11. In this way, depending on the phase difference between the rotors, a phase shift of the waveform of the induced voltage according to the rotation angle of the output shaft 3a occurs. In other words, the direction of the synthetic field is not a fixed direction with respect to the outer rotor 10 or the inner rotor 11 but changes according to the phase difference between the rotors.

  Next, with reference to FIGS. 6-9, the control apparatus 50 of the electric motor 3 in this embodiment is demonstrated. FIG. 6 is a block diagram showing a functional configuration of the control device 50 (hereinafter simply referred to as the control device 50) of the electric motor 3, and FIGS. 7A and 7B show the processing of the Ke estimation unit 69 provided in the control device 50. FIG. 8 is a block diagram showing processing functions of the angle correction unit 51 provided in the control device 50, and FIG. 9 is a graph for explaining processing of the angle correction unit 51. In FIG. 6, the electric motor 3 is schematically illustrated and the planetary gear mechanism 30 is expressed as a “phase variable mechanism”.

  The control device 50 of the present embodiment basically controls energization of the armature of the motor 3 by so-called dq vector control. That is, the control device 50 is a d-phase DC rotating coordinate system in which the motor 3 is a two-phase DC rotating coordinate system with the field direction (specifically, the direction of the combined field) as the d axis and the direction orthogonal to the d axis as the q axis. It is handled by converting to an equivalent circuit in the q coordinate system. 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 d axis is a so-called field axis, and the q axis is a so-called torque axis. Then, the control device 50 causes the electric motor 3 to generate a torque corresponding to a torque command value Tr_c (a torque command value generated in the output shaft 3a of the electric motor 3) given from the outside. The energization current of the child (the armature for three phases) is controlled. Further, in parallel with this energization control, the control device 50 controls the inter-rotor phase difference θd of the electric motor 3 via the phase difference changing device 15.

  In order to perform these controls, in the present embodiment, as sensors, current sensors 41 and 42 (for detecting currents in two phases of the three phases of the armature of the motor 3, for example, the U phase and the W phase) Current detector) and an angle detector 43 for detecting the rotation angle θm of the output shaft 3a of the motor 3 or the outer rotor 10 (rotation angle in a coordinate system fixed to the stator 12 of the motor 3). ing. The angle detector 43 corresponds to the angle detection means in the present invention, and is constituted by a resolver or the like. In the present embodiment, since the output shaft 3a and the outer rotor 10 rotate integrally, the respective rotation angles are the same.

  The control device 50 is an electronic 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 corrects the rotation angle θm (= rotation angle of the outer rotor 10) of the output shaft 3a detected by the angle detector 43, and the rotation angle θm corrected by the angle correction unit 51. A rotational speed calculation unit 52 for obtaining a rotational speed ωm (= dθm '/ dt) obtained by differentiating' (hereinafter referred to as a corrected rotational angle θm '), and an energization current of each phase of the motor 3 in an inverter circuit And an energization control unit 53 that is controlled via 44. Since the inverter circuit 44 is well known, the illustration thereof is omitted, but the upper arm and the lower arm have three-phase (three) switching elements (such as FETs), and the reflux connected in parallel to each switching element. And a diode. Note that a DC voltage is applied to the inverter circuit 44 from a power source (capacitor) of the electric motor 3 (not shown).

  Although details of the processing of the angle correction unit 51 will be described later, the corrected rotation angle θm ′ obtained by the angle correction unit 51 is the rotation angle of the synthetic field, in other words, the rotation angle of the dq coordinate system. means. Therefore, the rotational speed ωm obtained by differentiating this θm ′ means the rotational speed (angular speed) of the synthetic field or the rotational speed of the dq coordinate system. Hereinafter, the rotational speed ωm is referred to as a synthetic field rotational speed ωm. In the state where the inter-rotor phase difference θd is kept constant, the direction of the synthetic field is fixed with respect to the outer rotor 10, so the synthetic field rotation speed ωm is the rotation of the output shaft 3a. This corresponds to the speed (= the rotational speed of the outer rotor 10 = the rotational speed of the inner rotor 11 = dθm / dt).

  Supplementally, the energization control unit 53 corresponds to the energization control unit in the present invention, and the angle correction unit 51 corresponds to the rotation angle correction unit in the present invention.

  The energization control unit 53 removes unnecessary components from the output signals of the current sensors 41 and 42 to obtain current detection values Iu and Iw of the U-phase and W-phase of the armature of the motor 3, respectively. And the current of the d-axis armature (hereinafter referred to as d-axis current) by three-phase-dq conversion based on the detected current values Iu and Iw and the corrected rotation angle θm ′ obtained by the angle correction unit 51. And a three-phase-dq converter 62 for calculating a detected value Iq_s of a q-axis armature current (hereinafter referred to as a q-axis current).

  The energization control unit 53 sequentially determines a d-axis current command value Id_c that is a command value (target value) of the d-axis current and a q-axis current command value Iq_c that is a command value (target value) of the q-axis current. A current command calculation unit 63, a field control unit 64 for obtaining a correction value Idvol for correcting the d-axis current command value Id_c, and a value obtained by adding the correction value Idvol to the d-axis current command value Id_c (Id_c is corrected by Idvol) And a calculation unit 65 for obtaining a deviation ΔId (= Id_c + Idvol−Id_s) between the detected value Id_s of the d-axis current obtained by the three-phase-dq conversion unit 62 and the current command calculation unit 63. and a calculation unit 66 for obtaining a deviation ΔIq (= Iq_c−Iq_s) between the q-axis current command value Iq_c and the q-axis current detection value Iq_s obtained by the three-phase-dq conversion unit 62.

  Here, in the current command calculation unit 63, a torque command value Tr_c (a command value of torque generated in the output shaft 3a of the electric motor 3) given from the outside to the control device 50 and the rotation speed calculation unit 52 are used. The combined field rotation speed ωm and the estimated value Ke_s of the induced voltage constant Ke obtained by the Ke estimation unit 69 described later (value obtained in the previous calculation processing cycle) are input. The current command calculation unit 63 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 values (basic values) of the d-axis current and the q-axis current for causing the motor 3 to generate the torque of the torque command value Tr_c. .

  The torque command value Tr_c is determined according to, 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 3 as a driving power source. The torque command value Tr_c includes a power running torque command value and a regenerative torque command value. In this embodiment, the power running torque command value Tr_c is a positive value, and the regenerative torque command value Tr_c is a negative value. The value of

Further, the field controller 64 sets the phase voltage (induced voltage) of the armature of the electric motor 3 to a target voltage determined according to the power supply voltage Vdc of the electric motor 3 (DC voltage applied to the inverter circuit 44). The d-axis current is operated so as to match. For this reason, the field control unit 64 includes a power supply voltage Vdc of the motor 3 and a d-axis voltage command value Vd_c that is a voltage command value of each of the d-axis armature and the q-axis armature determined by the current control unit 67 described later. The q-axis voltage command value Vq_c is input. Then, the field control unit 64 traces a target voltage circle whose radius is a target voltage determined by the power supply voltage Vdc, based on the phase voltage obtained from the input d-axis voltage command value Vd_c and q-axis voltage command value Vq_c. As described above (in other words, the magnitude of the combined vector of Vd_c and Vq_c does not exceed the power supply voltage Vdc), the correction value Idvol for operating the d-axis current Id is determined. In this case, the correction value Idvol is determined by a feedback control law such as a PI control law from a deviation between the target voltage and the magnitude of the combined vector (= √ (Vd_c ² + Vq_c ² )).

  Further, the energization control unit 53 further determines the d-axis voltage command value according to the feedback control law such as the PI control law so that the deviations ΔId and Iq are brought close to 0 according to the deviations ΔId and ΔIq calculated as described above. A current controller 67 is provided for determining Vd_c and q-axis voltage command value Vq_c. When the d-axis voltage command value Vd_c and the q-axis voltage command value Vq_c are determined, the d-axis voltage command value and the q-axis voltage command value respectively obtained from the deviations ΔId and Iq by a Fordback control law such as a PI control law. In addition, it is preferable to obtain the d-axis voltage command value Vd_c and the q-axis voltage command value Vq_c 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. .

  Further, the energization control unit 53 converts the set of the d-axis voltage command value Vd_c and the q-axis voltage command value Vq_c determined by the current control unit 67 into the voltage command value of the armature of each phase, and the voltage command value Accordingly, an inverter control unit 68 for controlling the inverter circuit 44 by PWM control is provided.

  In this case, in addition to the d-axis voltage command value Vd_c and the q-axis voltage command value Vq_c, the corrected rotation angle θm ′ obtained by the angle correction unit 51 is also input to the inverter control unit 68. Then, the inverter control unit 68 converts the set of the d-axis voltage command value Vd_c and the q-axis voltage command value Vq_c to the voltage command value of the armature of each phase by dq-3 phase conversion according to the corrected rotation angle θm ′. Convert to Further, the inverter control unit 68 compares the voltage command value of the armature of each phase with a triangular wave or sawtooth wave having a predetermined phase with respect to the corrected rotation angle θm ′, so that each phase of the inverter circuit 44 is The control signal of the switching element corresponding to (ON / OFF signal of the gate of the switching element) is generated. Then, the inverter control unit 68 controls the inverter circuit with the control signal to apply the voltage of the voltage command value to the armature of each phase via the inverter circuit 44.

  With the processing function of the energization control unit 53 described above, the torque of the torque command value Tr_c is generated on the output shaft 3a of the electric motor 3 while preventing the phase voltage of the armature of each phase of the electric motor 3 from exceeding the power supply voltage Vdc. In addition, the energization current of the armature of each phase of the electric motor 3 is controlled.

  In the present embodiment, the energization control unit 53 further includes a Ke estimation unit 69 that estimates an actual induced voltage constant Ke of the electric motor 3.

  In this embodiment, the Ke estimation unit 69 estimates the induced voltage constant Ke of the motor 3 as follows (determines an estimated value Ke_s of the induced voltage constant Ke).

  In the dq coordinate system, the following expressions (1) and (2) are generally established among the d-axis voltage Vd, the q-axis voltage Vq, the d-axis current Id, and the q-axis current Iq.

Ke ・ ωm + R ・ Iq = Vq−ωm ・ Ld ・ Id (1)
Vd = R · Id-ωm · Lq · Iq (2)

Here, R is the resistance value of the d-axis armature and the q-axis armature, Ld is the inductance of the d-axis armature, and Lq is the inductance of the q-axis armature.

  In the present embodiment, the Ke estimation unit 69 obtains an estimated value Ke_s (hereinafter referred to as an induced voltage constant estimated value Ke_s) of the induced voltage constant Ke of the electric motor 3 based on the above formulas (1) and (2). More specifically, the Ke estimation unit 69 obtains an induced voltage constant estimated value Ke_s based on the following equation (3) obtained from the equation (1).

Ke_s = (Vq- [omega] m.Ld.Id-R.Iq) /. Omega.m (3)

In this case, as the values of Vq, Id, Iq, and ωm necessary for the calculation of the right side of Equation (3), the q-axis voltage command value Vq_c determined by the current control unit 67 and the three-phase-dq conversion unit 62, respectively. The detected value Id_s of the d-axis current and the detected value Iq_s of the q-axis current obtained by the above and the combined field rotational speed ωm obtained by the rotational speed calculation unit 52 are used. Further, as the value of Ld, the value of Ld is determined from the command value Id_c or the detected value Id_s of the d-axis current Id based on a predetermined data table as shown in the graph of FIG. The value is used for the calculation of equation (3). The graph of FIG. 7A represents the correlation between the d-axis armature inductance Ld and the d-axis current Id. In the present embodiment, the value of Ld is determined from Id_c or Id_s using such correlation between Ld and Id. Instead of the d-axis current command value Id_c, a value (Id_c + Idvol) obtained by correcting Id_c with a correction value Idvol obtained by the field control unit 64 may be used. Further, as the value of R, for example, a value determined by the following equation (4) obtained from the equation (2) is used.

R = (Vd + ωm · Lq · Iq) / Id (4)

The values of Vd, Iq, and ωm necessary for the calculation of the right side of the equation (4) are obtained by the d-axis voltage command value Vd determined by the current control unit 67 and the three-phase-dq conversion unit 62. The detected value Iq_s of the q-axis current and the combined field rotation speed ωm calculated by the rotation speed calculation unit 52 may be used. As the value of Lq, the value of Lq is determined from the command value Iq_c or detection value Iq_s of the q-axis current Iq based on a predetermined data table as shown in the graph of FIG. The value is used for the calculation of equation (4). The graph in FIG. 7B represents the correlation between the q-axis armature inductance Lq and the q-axis current Iq. In the present embodiment, the value of Lq is determined from Iq_c or Iq_s using such correlation between Lq and Iq.

  In addition, when calculating | requiring the value of R by Formula (4), the value of R cannot be calculated | required accurately, when the d-axis current Id is a value of 0 vicinity. As a countermeasure against this, for example, the value of R may be obtained as follows. That is, the value (= Id_c + Idvol) obtained by correcting the d-axis current command value Id_c determined by the current command calculation unit 63 with the correction value Idvol calculated by the field control unit 64 is maintained at a value close to 0. , The d-axis current command value is periodically changed between a positive value and a negative value in the vicinity of 0, and the time average value is reset to be maintained in the vicinity of 0. The deviation between the d-axis current command value reset in this way and the detected d-axis current value Id_s is input to the current control unit 67 as ΔId. In this state, the value of R is calculated by the following equation (5).

R = {(Vd1−Vd2) + ωm · Lq · (Iq1−Iq2)} / (Id1−Id2) (5)

Here, Vd1, Iq1, and Id1 are respectively a d-axis voltage, a q-axis current, and a d-axis current corresponding to a time (hereinafter referred to as time 1) when the d-axis current command value becomes a positive value (or a negative value). Vd2, Iq2, and Id2 are the d-axis voltage, q-axis current, d corresponding to the time when the d-axis current command value is opposite in polarity to that of Vd1, Iq1, and Id (hereinafter referred to as time 2). Means shaft current. As these values, the d-axis voltage command value Vd_c, the q-axis current detection value Iq_s, and the d-axis current detection value Id_s at the times 1 and 2 may be used. Further, the actual rotational speed of the combined field of the electric motor 3 and the actual inductance change of the q-axis armature within one cycle of changing the d-axis current command value are considered to be almost zero, and the equation (5) As the value of ωm, the value of the combined field rotation speed ωm calculated by the rotation speed calculation unit 52 at time 1 or time 2 may be used. Further, the value of Lq in the equation (5) is a value determined based on the data table shown in the graph of FIG. 7B from the q-axis current command value Iq_c or the detected value Iq_s at time 1 or time 2. Can be used.

  By determining the value of R in this way, the value of R can be appropriately determined even in a situation where the d-axis current Id is a value near zero.

  Supplementally, when the value of the induced voltage constant Ke is estimated by the equation (3), the value of R may be set to a predetermined fixed value. Moreover, since the value of R and the value of Lq are influenced by the temperature of the armature of the motor 3 or the permanent magnets 13 and 14, the temperature is detected or estimated, and the values of R and Lq are determined based on the temperature. You may make it estimate. Then, the value of Ke may be estimated using the estimated values of R and Lq.

  In addition, when the inter-rotor phase difference θd is detected using an appropriate sensor, the value of Ke is calculated from the detected value of θd based on the map showing the correlation shown in the graph of FIG. You may make it estimate.

  In addition to the angle correction unit 51, the rotation speed calculation unit 52, and the energization control unit 53, the control device 50 includes a Ke command calculation unit 54 that sequentially determines a command value (target value) Ke_c of the induced voltage constant Ke of the motor 3. A phase control unit 55 that determines a control command for controlling the phase difference between the rotors and outputs the control command to the phase difference changing device 15.

  The Ke command calculation unit 54 is sequentially input with the torque command value Tr_c, the power supply voltage Vdc of the electric motor 3, and the combined field rotation speed ωm obtained by the rotation speed calculation unit 52. Then, the Ke command calculation unit 54 sequentially determines a command value Ke_c of the induced voltage constant Ke (hereinafter referred to as an induced voltage constant command value Ke_c) according to a predetermined map from these input values Tr_c, ωm, and Vdc.

  In this case, the map is, for example, a combination voltage (vector sum) of the d-axis voltage and the q-axis voltage of the motor 3 with respect to a set of the torque command value Tr_c, the combined field rotation speed ωm, and the power supply voltage Vdc. The induced voltage constant command value Ke_c is set such that the energy efficiency (ratio of output energy to input energy) of the motor 3 can be increased as much as possible while preventing the magnitude from exceeding the power supply voltage Vdc.

  Here, generally, the smaller the induced voltage constant Ke (in other words, the greater the inter-rotor phase difference θd), the more the output shaft 3a of the motor 3 can be rotated in a higher speed range. In addition, the region where the energy efficiency of the electric motor 3 is high can be shifted to the high speed rotation side. Further, the output torque of the electric motor 3 can be increased as the induced voltage constant Ke is increased (in other words, the rotor phase difference θd is decreased). Therefore, the induced voltage constant command value Ke_c may be set in consideration of the characteristics of the motor 3 with respect to the induced voltage constant Ke as described above and the operation mode required of the motor 3, and there are various ways of setting. Is possible.

  In the present embodiment, when the Ke command calculation unit 54 keeps the combined field rotation speed ωm and the power supply voltage Vdc constant, 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 (in other words, the strength of the synthetic field increases).

  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 in a region where the combined field rotation speed ωm is high, and the combined field rotation speed ωm. Is set such that the value of Ke_c becomes smaller as the value of becomes larger (in other words, the strength of the synthetic field is lowered). When the torque command value Tr_c and the combined field rotation speed ωm are constant, the induced voltage constant command value Ke_c is basically set so that the value of Ke_c decreases as 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 3.

  The induced voltage constant estimated value Ke_s obtained by the Ke estimating unit 69 of the energization control unit 53 is inputted to the phase control unit 55, and the induced voltage constant command value Ke_c outputted from the Ke command calculating unit 54 is sequentially received. Entered. Based on these input values, the phase control unit 55 controls the phase difference changing device 15 to make Ke_s follow Ke_c (so that the actual induced voltage constant Ke matches the command value Ke_c). And the control command is output to the phase difference changing device 15. In the present embodiment, for example, a command value θd_c (hereinafter, referred to as a phase difference command value θd_c) for the phase difference between the rotors is determined as the control command. In this case, the phase difference command value θd_c is determined, for example, as a feedforward value determined according to Ke_c according to a deviation ΔKe (= Ke_c−Ke_s) between the induced voltage constant command value Ke_c and the induced voltage constant estimated value Ke_s. It is determined by correcting with the feedback correction amount. The feedforward value may be determined from Ke_c using a map set in advance as shown in the graph of FIG. The feedback correction amount may be determined from ΔKe by a feedback control law such as a proportional law or PID law.

  The phase difference changing device 15 controls the inter-rotor phase difference θd via the actuator 25 in accordance with the phase difference command value θd_c input from the phase control unit 55.

  Supplementally, in the present embodiment, the inter-rotor phase difference command value θd_c is used as a control command for the phase difference changing device 15, but it may be a command value for the operation amount of the actuator 25 of the phase difference changing device 15, for example. The control command may be any command that can define the operation of the actuator 25 of the phase difference changing device 15.

  The induced voltage constant estimated value Ke_s, which is an estimated value of the actual induced voltage constant Ke of the electric motor 3, is induced voltage according to the operation mode of the electric motor 3 by the processing of the Ke command calculating unit 54 and the phase control unit 55 described above. The inter-rotor phase difference θd is controlled via the phase difference changing device 15 so as to coincide with the constant command value Ke_c.

  Next, the processing of the angle correction unit 51, which has been described later, will be described. As described above, the direction of the combined field formed by combining the field of the permanent magnet 13 of the outer rotor 10 and the field of the permanent magnet 14 of the inner rotor 11 is relative to the outer rotor 10 or the inner rotor 11. It is not a fixed orientation but changes according to the phase difference between the rotors. In order to appropriately control the output torque of the electric motor 3 to a desired torque, it is necessary to control the energization currents of the armatures of the respective phases in accordance with the direction of the synthetic field. Specifically, when the energization current of the armature of each phase of the electric motor 3 is controlled by dq vector control as in the present embodiment, the 3-phase-dq conversion unit 62 of the energization control unit 53, It is necessary to input to the inverter control unit 68 a rotation angle of a dq coordinate system (or a rotation angle having a certain offset with respect to the rotation angle) in which the actual direction of the synthetic field coincides with the d-axis direction. is there.

  On the other hand, since the rotation angle θm detected by the angle detector 43 is the rotation angle of the outer rotor 10 or the output shaft 3a, the direction of the synthetic field is uniquely determined depending only on the rotation angle θm. Instead, the direction of the synthetic field (or the rotation angle of the dq coordinate system) also depends on the inter-rotor phase difference θd.

  Here, for example, the direction of the synthetic field when the inter-rotor phase difference θd is 0 [deg] or 180 [deg] is set as a reference direction, and the direction of the synthetic field at an arbitrary inter-rotor phase difference θd When the deviation angle from the reference direction is Δθm, this Δθm has a correlation as shown in the graph of FIG. 9 with respect to the inter-rotor phase difference θd. As shown in the figure, the rotor phase difference θd is 0 [deg] which is the phase difference between the rotors corresponding to the maximum field state, and 180 [deg] which is the phase difference between the rotors corresponding to the minimum field state. Δθm changes according to the inter-rotor phase difference θd with such a characteristic that Δθm has a maximum value (maximum value). In other words, the waveform of the change in Δθm accompanying the change in the rotor phase difference θd from 0 [deg] to 180 [deg] becomes a convex waveform (a waveform convex upward in FIG. 9).

  Referring to FIG. 4, Δθm at any rotor phase difference θd is the armature when the output shaft 3a of the motor 3 is rotated at a constant speed while maintaining the value of the phase difference θd between the rotors. The output shaft 3a of the electric motor 3 is rotated at a constant speed while maintaining the rotation angle θm of the output shaft 3a at which the induced voltage generated at 0 becomes 0 and the inter-rotor phase difference θd at 0 [deg] or 180 [deg]. This corresponds to a difference from the rotation angle of the output shaft 3a at which the induced voltage generated in the armature becomes zero.

  Therefore, in the present embodiment, the rotation angle θm detected by the angle detector 43 is corrected by the angle correction unit 51 according to the inter-rotor phase difference θd. For this correction, in addition to the rotation angle θm detected by the angle detector 43, the phase difference command value θd_c determined by the phase control unit 55 indicates the actual phase difference between the rotors to the angle correction unit 51. Entered as a parameter to represent.

  Then, the angle correction unit 51 corrects the rotation angle θm by the process shown in the block diagram of FIG. 8 to obtain the corrected rotation angle θm ′. More specifically, with reference to FIG. 8, the angle correction unit 51 first obtains the deviation angle Δθm from the phase difference command value θd_c by the angle correction amount calculation unit 51a, and calculates it as the correction amount of the rotation angle θm. (Hereinafter referred to as angle correction amount). In this case, in this embodiment, the correlation between the rotor phase difference θd and Δθm shown in the graph of FIG. 9 is previously mapped, and this map (which corresponds to the correlation data in the present invention) is illustrated in advance. Not stored in memory. Based on this map, the angle correction amount Δθm is determined from the phase difference command value θd_c. That is, the value of θd_c input to the angle correction unit 51 is set as the value of θd in the graph of FIG. 9, the value of Δθm corresponding to the value is obtained from the map, and the obtained value of Δθm is obtained as the angle correction amount Δθm. Determine as.

  Next, the angle correction unit 51 inputs the angle correction amount Δθm obtained as described above to the filter 51b, and performs a low-pass characteristic filtering process on Δθm by the filter 51b. As a result, an angle correction amount Δθm ′ used to actually correct the rotation angle θm is obtained. In this way, by applying low-pass filtering to Δθm, an angle correction amount Δθm ′ in which frequent fluctuations are suppressed can be obtained. Then, the angle correction unit 51 performs a process of adding the angle correction amount Δθm ′ to the rotation angle θm input from the angle detector 43 by the calculation unit 51c. Thus, a corrected rotation angle θm obtained by correcting the rotation angle θm with the angle correction amount Δθm ′ is obtained.

  The above is the details of the processing of the angle correction unit 51 in the present embodiment.

  By correcting the rotation angle θm detected by the angle detector 43 as described above, a corrected rotation angle θm ′ suitable as a rotation angle corresponding to the direction of the synthetic field (rotation angle of the dq coordinate system) is obtained. Can be requested. Then, the post-correction rotational speed θm ′ and the synthetic field rotational speed ωm obtained by differentiating the rotational speed θm ′ are used in the processing of the energization control unit 53, so that the operating efficiency of the motor 3 is reduced and the output torque is oscillated. The output torque of the torque command value Tr_c can be smoothly generated on the output shaft 3a of the electric motor 3 while suppressing.

  In the present embodiment, the angle correction unit 51 uses the phase difference command value θd_c as the parameter value in the present invention. For example, the induced voltage constant estimated value Ke_s obtained by the Ke estimation unit 69 or The value of the phase difference between the rotors obtained from the induced voltage constant estimated value Ke_s based on the map shown in the graph shown in FIG. 5 (this means the estimated value of the phase difference between the rotors) is the phase difference command. It may be used instead of the value θd_c. Alternatively, the command value of the operation amount of the actuator 25 of the phase difference changing device 15 corresponding to the phase difference command value θd_c may be used instead of the phase difference command value θd_c. When the inter-rotor phase difference θd is detected using an appropriate sensor, the detected value is used in place of the phase difference command value θd_c to obtain the angle correction amount Δθm. Good.

  In the embodiment, the rotation angle θm is corrected by the addition calculation of the angle correction amount Δθm ′. However, the rotation angle θm is corrected by a subtraction operation, a multiplication operation, a division operation, or the like. Also good.

  In the above embodiment, the direction of the synthetic field (rotation angle of the dq coordinate system) when the inter-rotor phase difference θd is 0 [deg] or 180 [deg] is used as the reference direction. The reference direction of the direction of the synthetic field (rotation angle of the dq coordinate system) when the interphase difference θd is a value between 0 [deg] and 180 [deg] (for example, θdx) may be used.

  In the above embodiment, the map is used to obtain the angle correction amount Δθm. However, the correlation between the rotor phase difference θd and the angle correction amount Δθm shown in the graph of FIG. Alternatively, the angle correction amount Δθm may be obtained using the approximate expression.

  In the above-described embodiment, the rotation angle of the outer rotor 10 (= the rotation angle of the output shaft 3a) is detected by the angle detector 43. Instead, the rotation angle of the inner rotor 11 is detected. May be. Even if the rotation angle of the inner rotor 11 is detected, the direction of the synthetic field (the rotation angle of the dq coordinate system) can be uniquely specified from the detected value and the parameter representing the inter-rotor phase difference θd.

The figure which shows the principal part of the internal structure of the electric motor in one Embodiment of this invention in the axial center direction of this electric motor. The skeleton figure which shows the drive mechanism for changing the phase difference between the two rotors of the electric motor of FIG. FIG. 3A is a diagram showing the phase relationship between the two rotors of the motor of FIG. 1 in the maximum field state, and FIG. 3B is a diagram of the two rotors of the motor of FIG. 1 in the minimum field state. The figure which shows a phase relationship. The graph which shows the induced voltage of the armature of the motor of FIG. 1 in a field maximum state, a field minimum state, and these intermediate states. The graph showing the relationship between the phase difference between two rotors of the electric motor of FIG. 1, and an induced voltage constant. The block diagram which shows the functional structure of the control apparatus of the electric motor in embodiment. FIGS. 7A and 7B are graphs for explaining the processing of the Ke estimation unit 69 provided in the control device of FIG. The block diagram which shows the processing function of the angle correction | amendment part 51 with which the control apparatus of FIG. 6 was equipped. The graph for demonstrating the process of the angle correction | amendment part 51 with which the control apparatus of FIG. 6 was equipped.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 3 ... Electric motor, 3a ... Output shaft, 10 ... Outer rotor (1st rotor), 11 ... Inner rotor (2nd rotor), 13, 14 ... Permanent magnet, 43 ... Angle detector (angle detection means), 50 ... Control Device 53: Energization control unit (energization control unit) 51: Angle correction unit (rotation angle correction unit)

Claims (4)

A first rotor and a second rotor, each of which generates a magnetic field by a permanent magnet, and an output shaft that can rotate integrally with the first rotor of the two rotors are coaxially provided, and the second rotor includes the first rotor. The strength of the synthetic field provided by synthesizing the field of the permanent magnets of each rotor by changing the phase difference between the two rotors by the relative rotation of the second rotor. Is a motor control device that can be changed,
Angle detection means for detecting the rotation angle of either one of the rotors;
A rotation angle correction means for acquiring a value of a parameter representing an actual phase difference between the two rotors, and correcting the detected rotation angle in accordance with the acquired value of the parameter;
An electric motor control device comprising: energization control means for controlling an energization current of an armature provided in a stator of the electric motor according to the corrected rotation angle.   The rotation angle correcting means stores in advance correlation data representing a correlation between the parameter value and the correction amount of the rotation angle, and is obtained based on the correlation data from the acquired parameter value. The motor control device according to claim 1, wherein the detected rotation angle is corrected according to an amount.   The rotation angle correction means includes means for performing a filtering process on the correction amount obtained based on the correlation data, and corrects the detected rotation angle according to the correction amount after the filtering process. The motor control device according to claim 2.   The value of the parameter corresponding to the phase difference between the two rotors where the strength of the combined field is maximized is set as the maximum field parameter value, and the phase difference between the two rotors where the strength of the combined field is minimized. When the corresponding parameter value is the minimum field parameter value, the correlation indicates that the waveform of the change in the correction amount according to the change in the parameter value is the maximum field parameter value and the minimum field parameter value. 4. The motor control device according to claim 2, wherein the correlation is a convex waveform having a predetermined value between the parameter value and the correction value having an extreme value.

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