JP2011155740A - Control device of motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a size of a mechanism which changes a phase difference between both rotors in a double structure in which the annular two rotors of a motor are coaxially arranged internally and externally with respect to an output shaft to reduce the size of the motor as a whole. <P>SOLUTION: The motor 10 includes an outside rotor 12 which is arranged inside a stator 14, has permanent magnets 12a, and generates field flux and an inside rotor 11 which has permanent magnets 11a and adjusts the field flux by using a relative angular position with respect to the outside rotor 12. When changing the phase difference between both the rotors 11, 12, an ECU 25c makes a field current flow to the stator 14 so that a torque for canceling a magnetic force torque generated between both the rotors 11, 12 is generated, and furthermore performs control for intensifying the field current so that torque which rotates the inside rotor 11 is generated after the magnetic force torque is canceled. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention has two rotors each generating a magnetic field flux by a permanent magnet, changes the phase difference between the two rotors, and increases the combined field strength of the permanent magnets of both rotors according to the changed phase difference. The present invention relates to a motor control device capable of adjusting the height.

  2. Description of the Related Art Conventionally, there is a motor control device described in Patent Document 1 as a motor control device that changes a phase difference between two rotors each generating a field flux by a permanent magnet. This electric motor has permanent magnets, includes an inner rotor and an outer rotor that are rotatably connected to the output shaft of the electric motor, and a stator is disposed on the outer periphery of the outer rotor via a gap. Both rotors have an annular shape, and have a double structure in which an annular outer rotor having a larger diameter is arranged coaxially with respect to the output shaft of the motor on the outer peripheral side of the inner rotor having a small diameter. ing.

  Such a phase difference between the two rotors is changed by the control device. When changing the phase difference between the two rotors, the control device reduces the rotational force (magnetic torque) acting between the rotors due to the magnetic force of the permanent magnets of the rotors. Controls the field current component. The stator current includes both field current and exciting current components. With this control, the driving force (driving torque) required to rotate the inner rotor relative to the outer rotor is smaller than when the field current component is not operated (when the field current component is set to 0). can do. As a result, it is possible to reduce the burden on the actuator that generates a driving force for rotating the inner rotor relative to the outer rotor. Since this reduction is possible, it is possible to reduce the size of the actuator and the mechanism for changing the phase difference between the two rotors.

JP 2008-43127 A

  However, in the electric motor control device disclosed in Patent Document 1, an actuator that rotates the inner rotor relative to the outer rotor can be reduced in size in order to change the phase difference between the inner rotor and the outer rotor, but the actuator is necessary. Therefore, there is a problem that the entire motor is enlarged accordingly.

  The present invention has been made in view of such circumstances, and in a double structure in which two annular rotors of a motor are arranged coaxially with respect to an output shaft inside and outside, the inner rotor is rotated relative to the outer rotor. It is an object of the present invention to provide a motor control device that can omit an actuator that generates a driving force for causing the motor to be downsized, thereby reducing the size of the entire motor.

  In order to achieve the above object, the invention according to claim 1 is provided with a stator having an armature core around which an armature coil is wound and fixed to a housing, and disposed on an inner peripheral side of the stator. An outer rotor that has a permanent magnet and generates a field flux, an inner rotor that has a permanent magnet and adjusts the field flux by a relative angular position with respect to the outer rotor, and a relative angle between the inner rotor and the outer rotor A motor having a rotor angle holding unit that mechanically holds a phase difference that is a position, and after releasing the holding of the phase difference at the rotor angle holding unit of the motor, the inner rotor is rotated to rotate between the two rotors. In a motor control apparatus that adjusts the phase difference and adjusts the field flux, when changing the phase difference between the rotors, the magnetic torque between the rotors generated by the permanent magnets of the rotors is canceled out. A control means is provided for controlling the field current to flow so as to generate a torque for rotating the inner rotor after canceling the magnetic torque, and causing a field current to flow through the stator to generate a torque. Features.

  According to this configuration, the attractive force generated by the permanent magnet between the inner rotor and the outer rotor is canceled out by the stator magnetic flux generated by applying a field current to the stator. After canceling the attractive force between the inner rotor and the outer rotor with the field current, if the field current is further increased, the inner rotor rotates a predetermined amount so that the polarity of the magnet of the inner rotor follows the magnetic flux generated by the current. Thus, the phase difference between the two rotors is changed.

  The invention according to claim 2 is characterized in that the permanent magnets of both the outer rotor and the inner rotor have a shape in which the minimum field magnetic flux of both the permanent magnets is zero.

  According to this configuration, when the relative phase difference between the two rotors is moved from 0 deg to 180 deg, the field magnetic flux amount can be stably changed from 0 to a predetermined amount.

  According to a third aspect of the present invention, the permanent magnets of both the outer rotor and the inner rotor have a shape in which a magnetic circuit in which the poles are not reversed is formed in the minimum field magnetic flux state by the both permanent magnets. It is characterized by that.

  According to this configuration, when the relative phase difference between the two rotors is moved from 0 deg to 180 deg, the field magnetic flux amount can be stably changed from 0 to a predetermined amount.

  The invention according to claim 4 is characterized in that the both permanent magnets have a shape in which the minimum field magnetic flux of both the permanent magnets is within the range of 0 to 20% of the maximum field magnetic flux.

  According to this configuration, for example, when the minimum field flux by the permanent magnets of both rotors is within the range of 20% of the maximum field flux, the amount of field flux is a predetermined amount even if the relative phase difference between both rotors is 0 deg. Less field current is required to turn.

  According to a fifth aspect of the present invention, the permanent magnet of the outer rotor is formed in a long rectangular plate shape, the longitudinal direction of which is directed in the radial direction of the outer rotor, and is arranged at predetermined intervals, and is magnetized in the circumferential direction. The permanent magnets of the inner rotor are in the form of a long rectangular plate, the longitudinal direction of which is oriented in the circumferential direction of the inner rotor and arranged at predetermined intervals, and are magnetized in the radial direction. The plurality of permanent magnets are arranged such that the end portions of the pair of permanent magnets of the outer rotor and the both end portions of one permanent magnet of the inner rotor face each other.

  According to this structure, the minimum field magnetic flux state by the permanent magnets of both rotors can be best maintained.

  According to a sixth aspect of the present invention, the control means applies a motor torque to the stator that is output from the rotors to the stator so as to maintain a command torque value when the phase difference between the rotors is changed. It is characterized in that the excitation current of the is controlled.

  According to this configuration, the motor torque can be made constant when the phase difference between the rotors is changed.

  According to a seventh aspect of the present invention, the control means stores a first map in which the phase difference command values between the rotors corresponding to the torque command value of the motor and the motor rotation speed are respectively associated with data. And the control means searches for the phase difference command value between the rotors according to the motor rotation speed and the torque command value of the motor based on the first map, and searches for the position between the rotors. It is characterized in that a current command value is calculated from the phase difference command value and a field current corresponding to the current command value is controlled to flow through the stator.

  According to this configuration, the phase difference between the two rotors can be changed to a predetermined phase difference.

  According to an eighth aspect of the present invention, the storage means includes a temperature of the permanent magnets of the two rotors and a limit command value for limiting the amount of the field current to prevent demagnetization of the permanent magnets. A second map associated with each data is stored, and the control means detects the temperature of the permanent magnet, obtains the limit command value corresponding to the detected temperature from the second map, and obtains the obtained value. The current command value is limited by the limited command value, and the field current corresponding to the limited current command value is controlled to flow through the stator.

  According to this configuration, it is possible to limit the field current of the stator according to the temperature of the permanent magnet, thereby preventing demagnetization of the permanent magnet.

1 is a configuration diagram of a motor drive system including a motor and a control device thereof according to an embodiment of the present invention. It is a block diagram of the motor of a maximum field magnetic flux state. (A) Relationship diagram between torque of inner rotor of motor and phase difference between both rotors, (b) Relationship diagram between field current flowing in stator of motor and phase difference between both rotors. (A) Configuration diagram when both rotors of the motor are in the minimum field magnetic flux state and the relative phase difference is 0 deg, (b) Configuration diagram when both rotors of the motor are in the maximum field magnetic flux state and the relative phase difference is 180 deg. FIG. 5 is a relationship diagram between an average torque between both rotors of a motor and a stator current phase. FIG. 4 is a relationship diagram between a magnetic flux amount ratio of permanent magnets of both an inner rotor and an outer rotor of a motor and a minimum field magnetic flux amount code. (A) It shows the flow of field flux in the minimum field flux state of the motor, (b) is a diagram showing the flow of field flux in the maximum field flux state of the motor. FIG. 5 is a relationship diagram between a field flux of a motor and a relative phase difference between both rotors. (A) Relationship diagram between motor torque and phase difference between both rotors, (b) Relationship diagram between motor excitation current and phase difference between both rotors. It is a flowchart which shows operation | movement in the case of changing the phase difference between the both rotors of a motor into a predetermined phase difference. FIG. 6 is a relationship diagram between a phase difference value between both rotors corresponding to a motor torque command value and a motor rotation speed, and a current command value of a field current according to the phase difference value between both rotors. It is a flowchart which shows operation | movement in the case of changing the phase difference between the both rotors of a motor to a predetermined | prescribed phase difference, preventing demagnetization of the permanent magnet of a motor. It is a relationship figure of the magnet temperature of a motor, and the command value of the current limitation of the field current of a motor.

  Embodiments of the present invention will be described below with reference to the drawings. However, parts corresponding to each other in all the drawings in this specification are denoted by the same reference numerals, and description of the overlapping parts will be omitted as appropriate.

  FIG. 1 is a configuration diagram of a motor drive system including a motor and a control device thereof according to an embodiment of the present invention.

  A motor 10 shown in FIG. 1 is mounted on a vehicle such as an electric vehicle or a hybrid vehicle. On the outer peripheral side of a small-diameter annular inner rotor 11, a larger-diameter annular outer rotor 12 is provided on a motor. It has a double structure arranged coaxially with respect to ten output shafts 13. The outer rotor 12 generates a field magnetic flux by a permanent magnet and is connected to the output shaft 13 so as to be rotatable integrally with the output shaft 13. The inner rotor 11 is disposed so as to be relatively rotatable with respect to the outer rotor 12 and the output shaft 13, and further serves to adjust the field flux according to the relative angular position with respect to the outer rotor 12. A stator 14 fixed to a housing (not shown) of the motor 10 is provided on the outer peripheral side of the outer rotor 12, and an armature for three phases (not shown) is attached to the stator 14. That is, the stator 14 is configured by fixing an armature in which an armature coil (not shown) is wound around an armature core (not shown) to the housing.

  The outer rotor 12 includes a plurality of permanent magnets 12a arranged at substantially equal intervals in the circumferential direction. The permanent magnet 12 a has a long rectangular plate shape and is embedded in the outer rotor 12 with its longitudinal direction directed in the radial direction of the outer rotor 12. In addition, each permanent magnet 12a is divided into a pair of two, and the opposing sides of the pair of permanent magnets 12a have the same polarity (N and N or S and S) and adjacent pairs. Are arranged in a state in which the opposite sides are different from each other (N and S).

  The inner rotor 11 also includes a plurality of permanent magnets 11a arranged at substantially equal intervals in the circumferential direction. The permanent magnet 11 a has substantially the same shape as the permanent magnet 12 a of the outer rotor 12, and its longitudinal direction is directed to the circumferential direction of the inner rotor 11, and both ends of one permanent magnet 11 a are a pair of the outer rotor 12. It is embedded in the inner rotor 11 so as to face each end of the permanent magnet 12a. Further, the permanent magnet 11a has opposite polarities (N and S) on the radially opposing side surfaces of the inner rotor 11.

  In FIG. 1, in the permanent magnet 11 a of the inner rotor 11, the side poles (for example, N) facing the pair of permanent magnets 12 a of the outer rotor 12 are poles (for example, S) between the pair of permanent magnets 12 a. Different arrangement states are shown. This state is a state in which the field magnetic flux emitted from the outer rotor 12 to the outside is the smallest, that is, a state in which the field magnetic flux by both the rotors 11 and 12 is the minimum (minimum field magnetic flux state). The minimum field magnetic flux state is also referred to as a stable state.

  In contrast, FIG. 2 shows the motor 10 in the maximum field flux state. In this maximum field magnetic flux state, the side poles (for example, N) facing the pair of permanent magnets 12a in the permanent magnet 11a are in the same arrangement state as the poles (for example, N) between the pair of permanent magnets 12a. This state is a state in which the field magnetic flux exiting from the outer rotor 12 is the largest, that is, the field magnetic flux generated by the rotors 11 and 12 is the maximum.

  The motor 10 having such a configuration can change the strength of the magnetic flux between the inner rotor 11 and the outer rotor 12 by rotating the inner rotor 11 with respect to the outer rotor 12. Further, a rotor angle holding portion 25d, which is a phase holding mechanism that mechanically holds the relative angular position between the rotors 11 and 12, is provided. When the phase difference between the rotors 11 and 12 is changed, it is performed after releasing the mechanical holding by the rotor angle holding unit, and is mechanically held after the phase difference is changed.

  Further, the motor 10 includes a phase difference detector 21 that detects a phase difference between the rotors 11 and 12 and a position sensor such as a resolver that detects a rotation position of the output shaft 13 of the motor 10 (a rotation angle of the outer rotor 12). 22 and currents for detecting currents of each of two phases (for example, the U phase and the W phase) of the armature of the motor 10 (a stator current including both field current and excitation current components). Sensors 23 and 24 and a control device 25 are provided.

  The control device 25 includes a converter 25a and an inverter 25b, and an ECU (electronic control unit: control means) 25c. Converter 25a boosts DC power of a battery (not shown), and inverter 25b converts the boosted DC power into three-phase AC power, and drives motor 10 with this three-phase AC power. On the other hand, when the motor 10 is a motor generator and the motor generator functions as a generator, AC power output from the motor generator is converted to DC power by the inverter 25b, and the converted DC power is stepped down by the converter 25a. And regenerated to the battery. Such a step-up / step-down operation of the converter 25a and a power conversion operation of the inverter 25b are controlled by the ECU 25c.

  That is, the ECU 25c receives the values of the phase difference detected by the phase difference detector 21, the rotation angle detected by the position sensor 22, and the stator current detected by the current sensors 23 and 24. Accordingly, the rotational drive of the motor 10 is controlled by controlling the converter 25a and the inverter 25b.

  Further, when changing the phase difference between the rotors 11 and 12, the ECU 25c is opposite to the phase changing direction generated between the rotors 11 and 12 by the magnetic force acting between the permanent magnets 11a and 12a of the rotors 11 and 12. The field current of the armature of the stator 14 in the motor 10 is controlled so as to cancel the torque in the direction and generate a phase difference changing torque in the same direction as the phase changing direction. In other words, the ECU 25c generates a torque that cancels the magnetic torque generated between the rotors 11 and 12, and controls the flow of the field current so as to generate a torque that rotates the inner rotor 11 after canceling the magnetic torque. Do. This control is called phase difference change control between both rotors.

  This will be described with reference to FIGS. 3 (a) and 3 (b). FIG. 3A is a relational diagram between the torque of the inner rotor 11 and the phase difference between the two rotors 11, 12, and FIG. 3B is a relation between the field current flowing through the stator 14 and the phase difference between the two rotors 11, 12. FIG. When the ECU 25c is not performing phase difference change control between both rotors, the motor 10 is driven in the field weakening region, and the field current of the stator 14 at this time is as indicated by a broken line segment IDa in FIG. It is controlled to a constant value. Further, torque is generated in the inner rotor 11 at this time so that a force that impedes rotation of the inner rotor 11 acts as shown by a mountain-shaped broken line T11a in (a).

  On the other hand, when the ECU 25c performs the phase difference change control between the two rotors, by passing the field current IDb as shown in (b), the inner rotor 11 is moved as shown by a reverse mountain-shaped broken line T11b in (a). Torque to rotate is generated.

  The flow of magnetic flux when the torque for rotating the inner rotor 11 is generated will be described with reference to FIGS. 4 (a) and 4 (b). FIG. 4A shows a case where both rotors 11 and 12 are in the minimum field flux state and the relative phase difference between both rotors 11 and 12 is 0 deg. FIG. 4B shows that both rotors 11 and 12 are in the maximum field flux state. The case where the relative phase difference of both the rotors 11 and 12 is 180 deg is shown.

  First, in the minimum field magnetic flux state (stable state) where no field current flows through the stator 14, as shown in FIG. 4A, the magnetic flux φ1 flowing through the inner rotor 11 flows from the permanent magnet 11a1 to the permanent magnet 11a2. This flows strongly through the circuit path as the magnetic flux φ2 flowing through the outer rotor 12 from the permanent magnet 12a3 through the permanent magnet 12a2 and returning as the magnetic flux φ1 to the permanent magnet 11a1 of the inner rotor 11. Further, it flows slightly from the pair of permanent magnets 12a1 and 12a2 of the outer rotor 12 to the N pole side of each other and slightly flows as the stator magnetic flux φS toward the pole of the stator 14. In this state, a magnetic torque that attracts the rotors 11 and 12 acts between the rotors 11 and 12.

  In such a minimum field magnetic flux state, when the field current IDb is caused to flow through the stator 14 by the phase difference change control between the two rotors as shown in FIG. 3 (b), it is indicated by white arrows φ1a, φSa or φ1b, φSb. Thus, the magnetic flux flowing through the permanent magnet 11a of the inner rotor 11 and the stator magnetic flux become stronger. As a result, the two magnetic fluxes φ1a and magnetic flux φSa or the magnetic flux φ1b and the magnetic flux φSb flow so as to generate repulsive torque, so that the magnetic torque generated between the inner rotor 11 and the outer rotor 12 is canceled out.

  When the field current IDb is further flown, a torque for rotating the inner rotor 11 is generated. As a result, the inner rotor 11 rotates to change the phase difference between the rotors 11 and 12, as shown in FIG. The maximum field flux state is obtained. In this maximum field magnetic flux state, the magnetic flux φ1 and the magnetic flux φS are in the same direction, and the magnetic flux φ1a and the magnetic flux φSa or the magnetic flux φ1b and the magnetic flux φSb are in the same direction, so that the inner rotor 11, the outer rotor 12 and the stator 14 are The sucking torque works.

  FIG. 5 shows a relationship between the average torque between the rotors and the stator current phase. As shown in the figure, the average torque between the rotors becomes negative when the stator current phase is near -90 deg. In a region where the torque is negative, the inner rotor 11 can be arbitrarily driven by a field current. Therefore, if the stator current phase is set to around -90 deg, a torque for rotating the inner rotor 11 to the maximum field magnetic flux state can be generated by the field current of the stator current at this time.

  Next, FIG. 7A shows an example of the rotor shape in the minimum field flux state, and FIG. 7B shows an example of the rotor shape in the maximum field flux state.

  6 (1) to (3), a magnetic flux amount ratio (internal / external rotor magnet magnetic flux amount ratio) between the permanent magnet 11a of the inner rotor 11 and the permanent magnet 12a of the outer rotor 12, and a minimum field magnetic flux amount code (at the time of the minimum field magnetic flux). The relationship with the rotor polarity.

  FIG. 6 (2) shows a relationship in which the amount of the magnetic flux φ1 of one inner permanent magnet 11a is equal to the amount of the magnetic flux φ2 × 2 of two pairs of the outer permanent magnets 12a associated with the permanent magnet 11a. This case is shown. That is, the shape, material, and magnetic circuit shape of one inner permanent magnet 11a and a pair of outer permanent magnets 12a associated therewith are set so that the magnetic flux φ1 and the two magnetic fluxes φ2 × 2 are equal. This is the case. In this case, the minimum field magnetic flux amount is zero, and when the relative phase difference [deg] between the rotors 11 and 12 is moved from 0 deg to 180 deg as shown in FIG. The amount of magnetic flux varies from 0 to a predetermined amount.

  FIG. 6A shows a case where the two magnetic fluxes φ2 × 2 are larger than the magnetic flux φ1. That is, the shape, material, and magnetic circuit shape of one inner permanent magnet 11a and a pair of outer permanent magnets 12a associated therewith are set so that the two magnetic fluxes φ2 × 2 are larger than the magnetic flux φ1. This is the case. That is, the magnetic circuit shape is such that the polarity of the rotor is not reversed in the minimum field magnetic flux state. In this case, the minimum field flux maintains polarity.

  Furthermore, in this case, as shown in FIG. 8, one inner permanent magnet 11a and a pair of outer sides associated therewith so that the minimum field flux is within a range Rg of 0 to 20% of the maximum field flux. The shape, material, and magnetic circuit shape of the permanent magnet 12a are determined. When the relative phase difference between the rotors 11 and 12 is moved from 0 deg to 180 deg, the change in the field magnetic flux amount is between L1 and L2. Thereby, compared with the case where the minimum field magnetic flux amount is 20% or more of the maximum field magnetic flux amount, the ratio of φ1 of the inner permanent magnet 11a is higher than the magnetic flux φ2 of the outer permanent magnet 12a. That is, since the sensitivity of the inner permanent magnet 11a to the stator magnetic flux is increased, the stator current for changing the relative phase difference between the inner and outer rotors can be reduced.

  FIG. 6 (3) shows the case where the magnetic flux φ1 is larger than the two magnetic fluxes φ2 × 2, and the polarity of the minimum field magnetic flux is reversed. In this case, as shown in FIG. 8, the amount of field magnetic flux when the relative phase difference [deg] between the rotors 11 and 12 is moved from 0 deg to 180 deg becomes a negative region as indicated by a line segment L3. So use in the positive area.

  Further, as indicated by a broken line Iq1 in FIG. 9B, the excitation current related to the motor torque during the phase difference change control between the rotors is constant between 0 ° and 180 ° between the rotors. Then, as shown by a broken line T1 in FIG. 9A, the motor torque increases as the phase difference between the rotors increases from 0 ° to 180 °. That is, unless the excitation current that contributes to the motor torque is not controlled, the amount of field flux increases and the motor torque increases (is not constant). Therefore, the motor 10 cannot hold the commanded torque.

  Therefore, as shown by the solid line segment T2 in FIG. 9 (a), the excitation torque is changed to a phase difference between the rotors of 0 ° to 180% as shown by the solid line segment Iq2 in (b). Decrease gradually as it gets larger. In other words, the excitation current is controlled so that the motor torque is constant.

  Next, a case where the phase difference between the rotors 11 and 12 is changed to a predetermined phase difference will be described with reference to the flowchart shown in FIG.

  If there is a request for changing the phase difference between the rotors in step S1, the ECU 25c detects the motor speed, the torque command value, and the phase difference θ between the rotors in step S2. In step S3, the ECU 25c searches for a phase difference value command value θref between the rotors corresponding to the motor rotation speed and the torque command value from a first map described later, using each detected value.

  This search is performed by the ECU 25c referring to the first map stored in the storage means. As shown in FIG. 11, the first map is a phase difference value between the rotors (for example, θ1) corresponding to the torque command value (for example, TI1, TI2) on the vertical axis and the motor rotational speed (for example, N1, N2) on the horizontal axis. , Θ2) are associated with each other. For example, if the motor rotation speed is N1 and the torque command value is TI1, the phase difference value between both rotors is θ1. It is assumed that the phase difference value θ1 between the rotors is retrieved in this way.

  Next, in step S4, the ECU 25c calculates Δθ, which is the difference between the phase difference value θref1 between both rotors retrieved in step S3 and the phase difference θ between both rotors detected. When Δθ = 0 is not satisfied, the process proceeds to step 5 where the ECU 25c calculates a command current value Iref corresponding to Δθ, and controls the stator current based on the command current value Iref in step 6. Then, it returns to step 2. By performing the processing from step 2 to step 6 until Δθ = 0 in step 4 is satisfied, the inner rotor 11 is rotated so that the phase difference between the two rotors becomes a predetermined phase difference.

  If there is no request for changing the phase difference between the rotors in step S1, or if Δθ = 0 is satisfied in step 4, the ECU 25c issues a command to maintain the relative phase difference between the rotors in step S7. The relative phase difference between the two rotors is held by giving to the holding unit.

  Next, a case where the phase difference between the rotors 11 and 12 is changed to a predetermined phase difference while preventing demagnetization of the permanent magnets 11a and 12a will be described with reference to the flowchart shown in FIG. In FIG. 12, the same parts as those shown in FIG. 10 are denoted by the same reference numerals, and the description thereof is omitted.

  After obtaining the current command value Iref1 in step S5, the ECU 25c detects the temperatures T of the outer permanent magnet 12a and the inner permanent magnet 11a in step S11. After this detection, in step S12, the current limit value Imax is retrieved from the second map according to the detected magnet temperature T. As shown in FIG. 13, the second map corresponds to the relationship between the limit command value on the vertical axis (eg, Imax1, Imax2) and the magnet temperature on the horizontal axis (eg, Te1, Te2) with a characteristic curve IT that descends to the right. In addition, the relationship between the limit command value Imax and the magnet temperature Te via the characteristic curve IT is shown as data. The characteristic curve IT shows that the field current is limited so as to prevent demagnetization when the temperature of the magnet becomes a predetermined high temperature or higher. Therefore, the higher the magnet temperature T, the lower the limit command value Imax that limits the field current. For example, when the magnet temperature is detected as Te2, the limit command value is Imax2. It is assumed that the limit command value Imax2 is retrieved in this way.

  Next, in step S13, it is determined whether or not the current command value Iref1 obtained in step S5 is equal to or less than the searched limit command value Imax2. If the current command value Iref1 exceeds the limit command value Imax2 as a result of this determination, the current command value Iref1 is limited to the limit command value Imax2 or less in step S14, and the field corresponding to the limited current command value Iref1 is determined in step S15. Magnetic current is passed through the stator 14. This limits the field current of the stator 14 and prevents magnet demagnetization.

  On the other hand, if the current command value Iref1 is equal to or smaller than the limit command value Imax2 as a result of the determination in step S13, a field current corresponding to the current command value Iref1 obtained in step S4 is passed through the stator 14 in step S15.

  As described above, the motor control device 25 according to the present embodiment has the armature core around which the armature coil is wound and is fixed to the housing, the stator 14 is disposed on the inner peripheral side of the stator 14, and is permanent. An outer rotor 12 that has a magnet 12 a and generates a field flux, an inner rotor 11 that has a permanent magnet 11 a and adjusts the field flux by a relative phase difference with respect to the outer rotor 12, and both the inner rotor 11 and the outer rotor 12. A motor 10 having a rotor angle holding unit that mechanically holds a relative phase difference between the rotors, and after releasing the holding of the phase difference at the rotor angle holding unit 25d of the motor 10, the inner rotor 11 is rotated. The magnetic flux is adjusted by adjusting the phase difference between the two rotors.

  In such a configuration, when the ECU 25c changes the phase difference between the two rotors, a field current is supplied to the stator 14 so as to generate a torque that cancels the magnetic torque generated between the two rotors. Control is performed to increase the field current so as to generate a torque for rotating the inner rotor 11 after the cancellation.

  As a result, by causing a field current to flow through the stator 14, the force by which the stator 14 magnetic flux due to the field current rotates the inner rotor 11 is greater than the attractive force between the inner rotor 11 and the outer rotor 12, and the inner rotor 11. And the outer rotor 12 are no longer attracted. The poles of the stator 14 due to the field current are attracted by the outer rotor 12 and repelled by the inner rotor 11, so that a force repelling the inner rotor 11 and the outer rotor 12 is generated. This is adjusted by the amount of field current by field current control. After canceling the attractive force between the inner rotor 11 and the outer rotor 12 by the field current, if the field current is further increased, the inner rotor 11 rotates by a predetermined amount, thereby changing the phase difference between the two rotors. Thus, since the actuator as in the prior art is not required to change the phase difference between the two rotors, the entire motor can be reduced in size accordingly.

  Further, the permanent magnets 11a and 12a of both the outer rotor 12 and the inner rotor 11 have a shape in which the minimum field flux by the both permanent magnets 11a and 12a is zero.

  Accordingly, when the relative phase difference between the rotors 11 and 12 is moved from 0 deg to 180 deg, the field magnetic flux amount can be stably changed from 0 to a predetermined amount.

  Further, the permanent magnets 11a and 12a of both the outer rotor 12 and the inner rotor 11 have a shape in which a magnetic circuit is formed in which the poles are not reversed in the minimum field magnetic flux state by the permanent magnets 11a and 12a.

  Accordingly, when the relative phase difference between the rotors 11 and 12 is moved from 0 deg to 180 deg, the field magnetic flux amount can be stably changed from 0 to a predetermined amount.

  Moreover, both the permanent magnets 11a and 12a were made into the shape from which the minimum field magnetic flux by the said permanent magnets 11a and 12a became more than the range of 0-20% of the maximum field magnetic flux.

  Thus, for example, when the minimum field flux by the permanent magnets 11a and 12a of both rotors 11 and 12 is within a range of 20% of the maximum field flux, or when the minimum field flux amount is 20% or more of the maximum field flux amount. In comparison, the ratio of φ1 of the inner permanent magnet 11a is higher than the magnetic flux φ2 of the outer permanent magnet 12a. That is, since the sensitivity of the inner permanent magnet 11a to the stator magnetic flux is increased, the stator current for changing the relative phase difference between the inner and outer rotors can be reduced.

  Further, the permanent magnet 12a of the outer rotor 12 has a long rectangular plate shape, the longitudinal direction of which is directed in the radial direction of the outer rotor 12 and arranged at a predetermined interval, and is magnetized in the circumferential direction. The permanent magnet 11a of the inner rotor 11 which is a magnet 12a has a long rectangular plate shape, the longitudinal direction of which is oriented in the circumferential direction of the inner rotor 11 and is arranged at predetermined intervals, and is magnetized in the radial direction. A plurality of permanent magnets 11 a are arranged in such a manner that the end portions of the pair of permanent magnets 12 a of the outer rotor 12 and the both end portions of one permanent magnet 11 a of the inner rotor 11 face each other. Thereby, the minimum field magnetic flux state by the permanent magnets 11a and 12a of both the rotors 11 and 12 can be best maintained.

  In addition, the ECU 25c controls the excitation current to the stator 14 so that the motor torque between the rotors 11 and 12 and the stator 14 that is output from both the rotors 11 and 12 is maintained at the command torque value when the phase difference between the rotors is changed. I made it. Thereby, the motor torque can be made constant when the phase difference between the two rotors is changed.

  Further, the ECU 25c includes storage means for storing a first map in which the phase difference values between the rotors corresponding to the torque command value of the motor 10 and the motor rotational speed are associated with each other by data, and the ECU 25c includes the first map. Based on the motor rotation speed and the torque command value of the motor, the phase difference command value θref between both rotors is retrieved, and the detected phase difference command value between both rotors and the detected current relative phase θ between the rotors The current command value is calculated from the difference between and the field current corresponding to the current command value is controlled to flow through the stator 14. Thereby, the phase difference between the two rotors can be changed to a predetermined phase difference.

  In addition, the storage means includes a temperature of the permanent magnets 11a and 12a of both rotors and a limit command value for limiting the amount of field current that prevents demagnetization of the permanent magnet with respect to the temperature of the permanent magnet. A second map associated with each data is stored, and the ECU 25c detects the temperature of the permanent magnet, obtains it from the second map corresponding to the detected temperature, and obtains a current command below the obtained limit command value. The value is limited, and the field current corresponding to the limited current command value is controlled to flow through the stator 14.

  Thereby, the field current of the stator 14 is limited according to the temperature of the permanent magnets 11a and 12a, and demagnetization of the permanent magnet is prevented.

DESCRIPTION OF SYMBOLS 10 Motor 11 Inner rotor 11a, 12a Permanent magnet 12 Outer rotor 13 Motor output shaft 14 Stator 21 Phase difference detector 22 Position sensor 23, 24 Current sensor 25 Controller 25a Converter 25b Inverter 25c ECU
25d Rotor angle holding part

Claims (8)

A stator having an armature core around which an armature coil is wound and fixed to a housing, an outer rotor disposed on the inner peripheral side of the stator and having a permanent magnet to generate a field flux, and a permanent magnet And an inner rotor that adjusts the field magnetic flux according to a relative angular position with respect to the outer rotor, and a rotor angle holding unit that mechanically holds a phase difference that is a relative angular position between the inner rotor and the outer rotor. In a motor control device that includes a motor and adjusts the field flux by adjusting the phase difference between the two rotors by rotating the inner rotor after releasing the holding of the phase difference in the rotor angle holding portion of the motor.
When the phase difference between the two rotors is changed, a field current is passed through the stator so as to generate a torque that cancels the magnetic torque between the rotors generated by the permanent magnets of the two rotors, and the magnetic torque is canceled out. A motor control apparatus comprising control means for performing control to increase the field current so as to generate torque for rotating the inner rotor later.   2. The motor control device according to claim 1, wherein the permanent magnets of both the outer rotor and the inner rotor have a shape in which a minimum field magnetic flux of both the permanent magnets is zero.   The permanent magnets of both the outer rotor and the inner rotor have a shape in which a magnetic circuit is formed in which the poles are not reversed in a minimum field magnetic flux state by both the permanent magnets. The motor control apparatus described.   4. The motor control device according to claim 3, wherein the two permanent magnets have a shape in which a minimum field flux by the two permanent magnets is within a range of 0 to 20% of the maximum field flux. 5. .   The permanent magnets of the outer rotor are a plurality of permanent magnets that are elongated in the shape of a rectangular plate and whose longitudinal direction is directed in the radial direction of the outer rotor and arranged at predetermined intervals and magnetized in the circumferential direction, The permanent magnets of the inner rotor are a plurality of permanent magnets which are elongated in the shape of a rectangular plate and whose longitudinal direction is oriented in the circumferential direction of the inner rotor and arranged at predetermined intervals and magnetized in the radial direction, The end portion of the pair of permanent magnets of the outer rotor and the both end portions of one permanent magnet of the inner rotor are disposed so as to face each other. The motor control apparatus described in 1.   The control means controls the excitation current to the stator so that the motor torque between the rotors output from the rotors and the command torque value is maintained when the phase difference between the rotors is changed. The motor control device according to any one of claims 1 to 5. The control means includes storage means for storing a first map in which the phase difference command values between the rotors corresponding to the torque command value of the motor and the motor rotational speed are respectively associated with data,
The control means searches for the phase difference command value between the rotors according to the motor rotation speed and the torque command value of the motor based on the first map, and from the searched phase difference command value between the rotors. The motor control device according to claim 1, wherein a current command value is calculated and a field current corresponding to the current command value is controlled to flow through the stator. The storage means includes second data in which the temperature of the permanent magnets of both the rotors and the limit command value for limiting the amount of the field current to prevent demagnetization of the permanent magnets are associated with each other by data. Remember the map,
The control means detects the temperature of the permanent magnet, determines the limit command value corresponding to the detected temperature from the second map, limits the current command value with the determined limit command value, and limits the limit command value. The motor control device according to claim 7, wherein a control is performed to cause a field current corresponding to the current command value to flow through the stator.

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