JP4135753B2 - Motor control device and motor control method - Google Patents

Description

  The present invention relates to an apparatus and method for driving and controlling an AC motor.

  In general, in a current control circuit of a three-phase AC motor, a control calculation is performed by converting a physical quantity of three-phase AC that is complicated to handle into a physical quantity of DC (see Patent Document 1). FIG. 12 shows a configuration of a control device for a three-phase AC motor that is generally widely used. In this type of control device, the direction of the exciting current component of the current flowing through the three-phase AC motor is set to the d axis, the direction of the torque current component is set to the q axis orthogonal to the d axis, and the rotating dq axis is orthogonal. By performing current control calculation with a direct current amount in the coordinate system, the current control deviation is reduced.

  On the other hand, in the AC motor, in order to reduce the size and increase the efficiency, the adoption of a rotor with an internally embedded magnet structure as shown in FIG. 13 and a stator with a concentrated winding structure are increasing. The former rotor has a structure that can effectively use magnet torque and reluctance torque, and a motor having such a rotor structure is called an IPM (Interior Permanent-magnet Motor). On the other hand, the latter stator has a structure that can greatly reduce the coil end. A motor having a rotor and a stator having the above-described structure is called a concentrated winding IPM motor, and is attracting attention as a small motor that can realize high efficiency.

See Japanese Patent Application Laid-Open No. 08-331885

  By the way, the concentrated winding IPM motor described above is a motor suitable for miniaturization and high efficiency, but has a characteristic that a spatial harmonic is large. Since a concentrated winding motor has a small number of slots per pole, the magnetic flux distribution is non-uniform and spatial harmonics are larger than a distributed winding motor.

  Compared to the SPM motor having a surface magnet structure in which the surface of the rotor is covered with a magnet as shown in FIG. 14, the IPM motor having an internally embedded magnet structure shown in FIG. 13 has the magnet embedded along the circumference of the rotor. Since there is a portion where the magnet is not present and a portion where the magnet is not present, the change in the magnetic flux is large, and thus the spatial harmonic component is large.

  If the motor's spatial harmonics are large, the harmonic component of the current flowing through the motor will be large, which will reduce the motor's efficiency and output, increase torque, current and voltage ripple, and reduce motor control performance. There is.

The present invention will be described with reference to FIG. 1 showing the configuration of an embodiment.
(1) The invention of claim 1 includes fundamental wave current command value determining means 1 for determining fundamental current command values id ^* and iq ^* of the motor current based on at least the torque command value Te ^* of the AC motor M; Harmonic current command value determining means 1 for determining the harmonic current command values idh ^* and iqh ^* of the motor current based on the torque command value Te ^* of the AC motor M, and current detection for detecting the actual current flowing through the AC motor M Basic wave control for matching the actual current detected by the means 11 and 12 and the current detecting means 11 and 12 with the fundamental wave current command values id ^* and iq ^* determined by the fundamental wave current command value determining means 1 command value vd ^*, the fundamental control command value determining unit 2 for determining a vq ^*, the harmonic component detection means 8 for detecting the harmonic component of the actual current detected by the current detection means 11, 12, Harmonic component of the motor current detected by the harmonics detection unit 8, the harmonic current command value is determined by the harmonic current command value determining section 1 idh ^*, the harmonic control command value for matching iqh ^* Harmonic control command value determining means 6 for determining vd ', vq', fundamental wave control command values vd ^* , vq ^* determined by the fundamental wave control command value determining means 2, and harmonic control command value determining means Based on the harmonic control command values vd ′ and vq ′ determined by 6, motor drive means 3, 4, and 10 for driving the AC motor M are provided, thereby achieving the above object.
(2) In the motor control device according to claim 2, the fundamental current command value id ^* , iq in the dq coordinate system rotating by the fundamental current command value determining means 1 in synchronization with the fundamental wave component of the armature linkage flux. ^* Is determined, and the harmonic current command value determining means 1 determines the harmonic current command values idh ^* and iqh ^* in the dhqh coordinate system that rotates in synchronization with the harmonic order component of the armature flux linkage. It is a thing.
(3) In the motor control device according to claim 3, the fundamental wave control command value determining means 2 is based on the fundamental wave component of the motor current in the dq coordinate system that rotates in synchronization with the fundamental wave component of the armature flux linkage. The fundamental wave control command values vd ^* and vq ^* for matching with the wave current command values id ^* and iq ^* are determined, and the harmonic control command value determining means 6 is synchronized with the harmonic order component of the armature linkage flux. Then, in the rotating dhqh coordinate system, the harmonic control command values vd ′ and vq ′ for making the harmonic component of the motor current coincide with the harmonic current command values idh ^* and iqh ^* are determined.
(4) The motor control device according to claim 4 is a fundamental wave current command for maximizing efficiency while matching the motor torque with the torque command value by the fundamental wave current command value determining means 1 and the harmonic current command value determining means 1. The values id ^* and iq ^* and harmonic current command values idh ^* and iqh ^* are determined.
(5) In the motor control device according to claim 5, the fundamental wave which minimizes the torque ripple while matching the motor torque with the torque command value by the fundamental wave current command value determining means 1 and the harmonic current command value determining means 1. The current command values id ^* and iq ^* and the harmonic current command values idh ^* and iqh ^* are determined.
(6) In the motor control device according to claim 6, the fundamental current that minimizes the voltage ripple while making the motor torque coincide with the torque command value by the fundamental current command value determining means 1 and the harmonic current command value determining means 1. The command values id ^* and iq ^* and the harmonic current command values idh ^* and iqh ^* are determined.
(7) In the motor control device according to claim 7, the fundamental wave current that minimizes the current ripple while matching the motor torque with the torque command value by the fundamental wave current command value determining means 1 and the harmonic current command value determining means 1. The command values id ^* and iq ^* and the harmonic current command values idh ^* and iqh ^* are determined.
(8) The motor control device according to claim 8 is a fundamental wave current command that maximizes efficiency while matching the motor torque with the torque command value by the fundamental wave current command value determining means 1 and the harmonic current command value determining means 1. Values id ^* , iq ^* and harmonic current command values idh ^* , iqh ^* , fundamental current command values id ^* , iq ^* and harmonic current command values that minimize torque ripple while matching motor torque to torque command values idh ^* , iqh ^* , fundamental current command values id ^* , iq ^* , harmonic current command values idh ^* , iqh ^* , and motor torque to minimize voltage ripple while matching motor torque to torque command value fundamental current command value id of the current ripple to a minimum while matching the value ^*, iq ^* and the higher harmonic current command value idh ^*, determines the iqh ^*, detecting the operating state of the motor That the operating state detection means, the fundamental wave current command value is determined by the fundamental wave current command value determining section 1 and harmonic current command value determining section 1 id ^*, iq ^* and the higher harmonic current command value idh ^*, iqh ^* of Current command value selection means 1 for selecting an optimum current command value id ^* , iq ^* , idh ^* , iqh ^* according to the operating state of the motor.
(9) The motor control device according to claim 9 makes the motor torque coincide with the torque command value when the current command value selection means 1 detects the motor operating state in the predetermined region where the motor torque is close to the maximum value. However, the fundamental wave current command values id ^* and iq ^* and the harmonic current command values idh ^* and iqh ^* that minimize the current ripple are selected.
(10) In the motor control device according to claim 10, when the current command value selection means 1 detects a motor operating state within a predetermined range in which both the motor torque and the motor rotation speed are low, the motor torque is set to the torque command value. The fundamental current command values id ^* and iq ^* and the harmonic current command values idh ^* and iqh ^* that minimize the torque ripple while matching are selected.
(11) The motor control device according to claim 11 makes the motor torque coincide with the torque command value when the current command value selection means 1 detects the motor operation state in the predetermined region where the motor output is close to the maximum value. However, the fundamental wave current command values id ^* and iq ^* and the harmonic current command values idh ^* and iqh ^* that minimize the voltage ripple are selected.
(12) In the motor control device according to claim 12, the current command value selection means 1 causes the motor torque and the motor output not to be in a predetermined region close to their maximum values, and the motor torque and the motor rotation speed are within a predetermined range. When no motor operating condition is detected, the fundamental current command values id ^* and iq ^* and the harmonic current command values idh ^* and iqh ^* that maximize the efficiency while matching the motor torque to the torque command value are selected. It is what I did.

  In the section of the means for solving the above-described problem, a diagram of an embodiment is used for easy understanding of the description. However, the present invention is not limited to the embodiment.

(1) According to the invention of claim 1, while the conventional motor control device controls only the fundamental current component, the harmonic current component can also be controlled to an arbitrary value, and the spatial harmonics For a motor having a large space, it is possible to improve output while reducing efficiency, and to reduce torque, voltage and current ripple, and to improve the control performance of a motor having large spatial harmonics.
(2) According to the invention of claim 2, the fundamental wave current and the harmonic current can be accurately controlled, respectively, and the above effect of claim 1 can be achieved with certainty.
(3) According to the invention of claim 3, the fundamental wave current and the harmonic current can be converted into direct current amounts, respectively, and current control with good follow-up can be realized, and the effect of claim 1 can be achieved reliably. Can do.
(4) According to the invention of claim 4, it is possible to obtain high efficiency that cannot be achieved only by controlling the fundamental current component as in the conventional motor control device.
(5) According to the invention of claim 5, it is possible to obtain a torque ripple reduction effect that cannot be achieved only by controlling the fundamental current component as in the conventional motor control device. In particular, when applied to an electric vehicle using a motor as a drive source, vibration and noise caused by torque ripple can be reduced in a low-speed and low-torque driving state, and riding comfort can be improved.
(6) According to the invention of claim 6, it is possible to obtain a voltage ripple reduction effect that cannot be achieved only by controlling the fundamental current component as in the conventional motor control device. In particular, when the motor is operated near the maximum output line, the amount of reduction of the fundamental voltage due to voltage ripple can be reduced, and the motor efficiency is improved and the output is increased in the field-weakening region, that is, the constant output control region. Can do.
(7) According to the invention of claim 7, it is possible to obtain a current ripple reduction effect that cannot be achieved only by controlling the fundamental wave current component as in the conventional motor control device. In particular, when the motor is operated in the vicinity of the maximum torque line, the reduction amount of the fundamental current due to the current ripple can be reduced, and the motor torque can be increased in the constant torque control region.
(8) According to the invention of claim 8, the optimum current command value according to the operating state of the motor can be selected, and the above effect of claim 1 can be achieved in all operating states of the motor.
(9) According to the invention of claim 9, when the motor is operated in the vicinity of the maximum torque line, the reduction of the fundamental wave current due to the current ripple can be reduced, and the motor torque is increased in the constant torque control region. be able to.
(10) According to the invention of claim 10, vibration and noise caused by torque ripple can be reduced in a low-speed and low-torque motor operating state, and when applied to an electric vehicle using a motor as a drive source, the ride comfort is reduced. Improvements can be made.
(11) According to the invention of claim 11, when the motor is operated in the vicinity of the maximum output line, the reduction of the fundamental voltage due to the voltage ripple can be reduced, and the motor in the field weakening region, that is, the constant output control region. The efficiency can be improved and the output can be increased.
(12) According to the invention of claim 12, high motor drive efficiency can be obtained in the normal operation state of the motor.
(13) According to the invention of claim 13, the conventional motor control device controls only the fundamental wave current component, whereas the harmonic current component can also be controlled to an arbitrary value, and the spatial harmonics. For a motor having a large space, it is possible to improve output while reducing efficiency, and to reduce torque, voltage and current ripple, and to improve the control performance of a motor having large spatial harmonics.

<< First Embodiment of the Invention >>
A first embodiment for improving motor efficiency and output will be described. FIG. 1 shows the configuration of the first embodiment. The motor control apparatus of this embodiment performs vector control that realizes torque control equivalent to a DC motor with a three-phase AC motor.

  The motor control device of this embodiment includes a fundamental current control circuit and a harmonic current control circuit. The fundamental current control circuit includes a d-axis corresponding to the excitation current components of the currents iu, iv and iw flowing through the three-phase AC motor M and a q-axis corresponding to the torque current component, and rotates in synchronization with the motor rotation. This circuit controls fundamental wave components of motor currents iu, iv, and iw in an orthogonal coordinate system (hereinafter referred to as fundamental wave coordinate system) dq.

  On the other hand, the harmonic current control circuit is an orthogonal coordinate system (hereinafter referred to as harmonic coordinates) that rotates at a frequency of a harmonic component of a predetermined order that is generated when the motor currents iu, iv, iw are controlled only by the fundamental current control circuit. Dhqh, in other words, harmonics included in the motor currents iu, iv, and iw in the harmonic coordinate system dhqh that rotates at a frequency that is an integral multiple of the frequency of the fundamental component of the motor currents iu, iv, and iw. A circuit for controlling the components.

In FIG. 1, the torque control unit 1 calculates a d-axis current command value id ^* and a q-axis current command value iq ^* in the fundamental wave coordinate system dq based on the torque command value Te ^* and the motor rotation speed ωe, The dh-axis current command value idh ^* and the qh-axis current command value iqh ^* in the harmonic coordinate system dhqh are calculated.

The fundamental wave current control unit (dq axis current control unit) 2 is a fundamental wave voltage command for the d axis and q axis for making the actual currents id and iq of the d axis and q axis coincide with the command values id ^* and iq ^* , respectively. The values vd ^* and vq ^* are calculated. The adder 3 includes fundamental wave voltage command values vd ^* and vq ^* generated by the fundamental wave current control unit 2, and a harmonic voltage command generated by a harmonic current control unit 6 and a dhqh / dq conversion unit 7 which will be described later. The values vd ′ and vq ′ are added to obtain the final d-axis voltage command value (vd ^* + vd ′) and the q-axis voltage command value (vq ^* + vq ′).

Based on the phase θe of the fundamental wave coordinate system dq synchronized with the motor rotation as viewed from the three-phase AC coordinate system, the dq / 3-phase converter 4 is a voltage command value (vd ^* + vd ′) for the d-axis and the q-axis. (Vq ^* + vq ′) is converted into a three-phase AC voltage command value vu ^* , vv ^* , vw ^* . The three-phase / dq converter 5 is based on the phase θe of the fundamental wave coordinate system dq synchronized with the motor rotation viewed from the three-phase AC coordinate system, and the actual currents iu, iv, iw (= −) of the three-phase AC motor M. iu−iv) is converted into actual currents id and iq on the d-axis and the q-axis. The fundamental wave current control unit 2 and the three-phase / dq conversion unit 5 constitute a fundamental wave current control circuit.

A harmonic current control unit (dhqh-axis current control unit) 6 is configured to match the dh-axis and qh-axis actual currents idh and iqh with the current command values idh ^* and iqh ^* , respectively. Command values vdh ^* and vqh ^* are calculated. The dhdq / dq converter 7 converts the dh-axis and qh-axis harmonic voltage command values vdh ^* and vqh ^* into the d-axis and q-axis harmonic voltage command values vd ′ and vq ′. The high-pass filter 8 extracts high-frequency components by filtering the actual currents id and iq on the dq axis based on the motor rotation speed ωe. The dq / dhqh converter 9 has the above-described harmonic coordinate system dhqh, and converts the harmonic components of the actual currents id and iq of the fundamental coordinate system dq into the actual currents idh and iqh of the harmonic coordinate system dhqh. Note that the harmonic current control unit 6, the three-phase / dq conversion unit 5, the high-pass filter 8, and the dq / dhqh conversion unit 9 constitute a harmonic current control circuit.

The power conversion unit 10 switches a DC voltage of a DC power source (not shown) such as a battery according to a three-phase AC voltage command value vu ^* , vv ^* , vw ^* by a power conversion element such as an IGBT, and the three-phase AC voltage U , V and W are applied to the three-phase AC motor M. The encoder PS is connected to the three-phase AC motor M and detects the rotational position θm of the motor M. The current sensors 11 and 12 detect actual currents iu and iv of the U phase and the V phase of the three-phase AC motor M. The phase speed calculator 13 calculates the rotational speed ωe of the motor M and the phase θe of the fundamental wave coordinate system dq viewed from the three-phase AC coordinate system based on the rotational position signal θm from the encoder PS.

  Next, the fundamental wave coordinate system dq and the harmonic coordinate system dhqh will be described using an IPM motor having a large spatial harmonic as an example. FIG. 2 shows the armature interlinkage magnetic flux (U-phase winding) formed by the magnet of the IPM motor when there is no spatial harmonic. FIG. 3 shows the armature interlinkage magnetic flux (U-phase winding) formed by the magnet of the IPM motor when the fifth-order component spatial harmonic exists.

  The magnetic flux changes in a sine wave shape with respect to the change in the rotation angle of the motor. Usually, the direction of the armature flux linkage vector is taken as the d axis, and the direction orthogonal to the d axis is taken as the q axis. Conventionally, physical quantities such as voltage and current in a three-phase AC coordinate system are converted into physical quantities in a dq axis coordinate system (fundamental wave coordinate system), and motor control is performed on the dq axis. On the other hand, in this embodiment, the fundamental wave component of physical quantities such as voltage and current is handled in the dq axis coordinate system as in the prior art, and the harmonic component indicates the direction of the armature flux linkage vector dh for each order. A direction perpendicular to the dh axis is taken as the qh axis, and is handled in the dhqh coordinate system (harmonic coordinate system). When the fifth harmonic component is included as shown in FIG. 3, the armature interlinkage magnetic flux is divided into a fundamental component and a fifth harmonic component, and the fundamental component armature chain. The direction of the flux vector is d-axis, the direction orthogonal to the d-axis is q-axis, and the direction of the armature flux linkage vector of the fifth harmonic component is dh-axis and is orthogonal to the dh-axis. The direction is on the qh axis. Therefore, the fundamental wave coordinate system dq is a coordinate system that rotates in synchronization with the fundamental wave component of the armature linkage flux, and the harmonic coordinate system dhqh rotates in synchronization with the harmonic order component of the armature linkage flux. Coordinate system.

The conventional motor control device controls the motor torque by the magnetic flux and current of the fundamental wave component. The efficiency and output of the motor that is driven and controlled by this conventional control device will be described. The output torque Te of the motor including the spatial harmonic component is expressed by the following equation.
Te = P (φd · id−φq · iq)
= P {(φd_1 + φd_h) (iq_1 + iq_h) − (φq_1 + φq_h) (id_1 + id_h)}
= P {(φd_1 · iq_1 + φq_1 · id_1) + (φd_h · iq_h + φq_h · id_h)
+ (Φd_h · iq_1 + φq_h · id_1) + (φd_1 · iq_h + φq_1 · id_h)} (1)
In the above equation, P is the number of pole pairs, φd is the d-axis armature linkage flux, φd_1 is the fundamental component of the d-axis armature linkage flux, φd_h is the harmonic component of the d-axis armature linkage flux, φq is q Axis armature linkage flux, φq_1 is the fundamental wave component of q-axis armature linkage flux, and φq_h is a harmonic component of q-axis armature linkage flux. Also, id is the d-axis current, id_1 is the fundamental component of the d-axis current, id_h is the harmonic component of the d-axis current, iq is the q-axis current, iq_1 is the fundamental component of the q-axis current, and iq_h is the q-axis current. Harmonic component.

Since the fundamental wave component of the d-axis current id in the fundamental wave coordinate system dq is id_1 and the harmonic component is id_h,
id = id_1 + id_h (2)
In addition, since the fundamental wave component of the q-axis current iq in the fundamental wave coordinate system dq is iq_1 and the harmonic component is iq_h,
iq = iq_1 + iq_h (3)

In this embodiment, since the harmonic current is controlled by the harmonic coordinate system dhqh, the torque control unit 1 uses the d-axis current command value id ^* of the excitation current component and the q-axis current of the torque current component in the fundamental wave coordinate system dq. thereby calculating a command value iq ^*, and calculates the qh-axis current command value dh-axis current command value idh ^* and the torque current component of the excitation current component at harmonic coordinate system dhqh iqh ^*, the fundamental wave current control circuit 2, 5 The dq axis fundamental currents id and iq are controlled so as to coincide with their command values id ^* and iq ^* , and the dhqh axis harmonic currents idh and iqh are obtained by the harmonic current control circuits 5, 6, 8, and 9. Control is performed so as to match the command values idh ^* and iqh ^* . In the following description, in order to make the description easy to understand, fundamental wave currents id_1 and iq_1 and harmonic currents id_h and iq_h are handled in the fundamental wave coordinate system dq, and finally the dq axis harmonic currents id_h and iq_h are converted into dhqh axis harmonics. The wave currents idh and iqh are converted.

  The first term on the right side of Equation 1 represents the torque generated by the fundamental wave component of the armature flux linkage of the motor and the fundamental wave component of the current. The second term represents the torque generated by the harmonic component of the armature flux linkage of the motor and the harmonic component of the current. The third term represents the torque generated by the harmonic component of the armature flux linkage of the motor and the fundamental component of the current. Furthermore, the fourth term represents the torque generated by the fundamental wave component of the armature flux linkage of the motor and the harmonic component of the current.

  Since the third term and the fourth term on the right side of Equation 1 are the products of the armature flux linkage component and the current component having different orders, the time average value thereof is 0 and does not contribute to the average torque output from the motor. However, since the first term is the product of the fundamental wave component of the armature linkage flux and the fundamental wave component of the current, it naturally contributes to the average torque, and the second term is the harmonic component of the armature linkage flux. And the harmonic component of the current, both have the same harmonic component order and contribute to the average torque. The conventional motor control device performs fundamental wave current control in the dq coordinate system, that is, control for setting the current distortion to 0, and only the torque of the first term on the right side of Equation 1 can be used. Therefore, in the conventional control device, the efficiency of the motor is low and the output is also low.

  Therefore, in the first embodiment, in addition to controlling the motor torque by the magnetic flux and current of the fundamental wave component, the motor torque is controlled by the magnetic flux and current of the harmonic component to improve the motor efficiency. Improve output.

  First, the effect of the harmonic current flowing in the motor on the efficiency is considered. FIG. 4 is a diagram showing the relationship between the harmonic current component and the overall efficiency when the dq-axis currents id and iq, which are the fundamental wave current components, are constant, and FIG. 4A shows the case where the qh-axis current iqh is zero. (B) shows the total efficiency for the qh-axis current iqh when the dh-axis current idh is zero. As is apparent from the figure, the efficiency is not maximized when the harmonic current idh or iqh is set to 0, and the efficiency is maximized when a certain amount of harmonic current is passed. That is, the overall efficiency can be improved by superimposing the harmonic current on the fundamental current compared to the conventional control method in which the motor is driven and controlled only by the fundamental current.

FIG. 5 shows a detailed configuration of the torque control unit 1 according to the first embodiment. The torque control unit 1 calculates the d-axis current corresponding to the torque command value Te ^* and the motor rotational speed ωe from the maximum efficiency id map 1a in which data of the torque command value and the d-axis current command value with respect to the motor rotational speed is stored. The command value id ^* is calculated from the table. Further, from the maximum efficiency iq map 1b in which data of the torque command value and the q-axis current command value with respect to the motor rotation speed are stored, the q-axis current command value iq ^* corresponding to the torque command value Te ^* and the motor rotation speed ωe ^. Is calculated.

Similarly, a dh-axis current command value idh corresponding to the torque command value Te ^* and the motor rotation speed ωe is obtained from the maximum efficiency idh map 1c storing data of the torque command value and the dh-axis current command value with respect to the motor rotation speed. ^* Is calculated. Further, from the maximum efficiency iqh map 1d in which data of the torque command value and the qh-axis current command value with respect to the motor rotation speed is stored, the qh-axis current command value iqh ^* corresponding to the torque command value Te ^* and the motor rotation speed ωe ^. Is calculated.

These maps 1a to 1d contain the command values of the fundamental wave current and the harmonic current that maximize the total efficiency among the combinations of the current command values for making the motor torque Te coincide with the torque command value Te ^*. It has been.

According to the first embodiment, it is possible to efficiently output from the motor a torque Te that coincides with the torque command value Te ^* at any motor rotation speed ωe.

<< Second Embodiment of the Invention >>
A second embodiment for minimizing the torque ripple of the motor will be described. The configuration of the second embodiment is the same as the configuration of the first embodiment shown in FIG. 1 except for the torque control unit 1, and the description of the overall configuration is omitted, with the focus on the differences. explain.

  The third term and the fourth term on the right side of Equation 1 are products of armature flux linkage and current of different orders, and thus do not contribute to the average torque, but these become torque ripple components. In the conventional motor control device, control of the fundamental wave current in the dq axis coordinate system, that is, control to set the harmonic component of the current to 0, the fourth term is 0, but the third term is 0. Torque ripple component. That is, the conventional control apparatus cannot reduce the torque ripple of a motor having a large spatial harmonic. In electric vehicles, the torque ripple of this motor causes discomfort to the passengers and must be reduced.

  Therefore, in the second embodiment, the relationship between the current of the IPM motor in which spatial harmonics exist and the output torque is analyzed, and the current condition for deriving the torque ripple to 0 by expressing the torque ripple by a mathematical expression is derived. To do.

The output torque Te of the IPM motor can be expressed as the sum of the magnet torque Tem and the reluctance torque Ter.
Te = Tem + Ter
= P (φdm · iq−Lqd · id · iq) (4)
In the above equation, Tem is the magnet torque, Ter is the reluctance torque, φdm is the armature flux linkage (magnet), and Lqd is the dq axis inductance difference (= Lq−Ld = Lqd_1 + Lqd_h).

First, the magnet torque Tem is calculated.
Tem = P ・ φdm ・ iq
= P (φdm_1 + φdm_h) (iq_1 + iq_h)
= P (φdm_1 · iq_1 + φdm_h · iq_1 + φdm_1 · iq_h + φdm_h · iq_h)
= P · φdm_1 · iq_1 + P (φdm_h · iq_1 + φdm_1 · iq_h + φdm_h · iq_h) (5)
In the above equation, φdm_1 is a fundamental wave component (magnet component) of the armature interlinkage magnetic flux, and φdm_h is a harmonic component (magnet component) of the armature interlinkage magnetic flux. The first term on the right side of Equation 5 represents the fundamental wave component torque, and the second term represents the torque ripple component. Therefore, if there is a current condition for setting the second term to zero, the ripple component of the magnet torque can be set to zero.
φdm_h · iq_1 + φdm_1 · iq_h + φdm_h · iq_h = 0 (6)
That means
iq_h = −φdm_h · iq_1 / (φdm_1 + φdm_h) (7)
Here, if the fundamental wave component of the armature flux linkage formed by the magnet is sufficiently larger than the harmonic component (φdm_1 >> φdm_h), Equation 7 can be approximated by the following equation.
iq_h = −φdm_h · iq_1 / φdm_1 (8)
From the above calculation, it can be seen that the condition for reducing the ripple of the magnet torque Tem to 0 is that the harmonic component iq_h of the q-axis current should be a value expressed by Equation 8.

Next, the reluctance torque Ter is calculated.
Ter = -P ・ Lqd ・ id ・ iq
= P (Lqd_1 + Lqd_h) (id_1 + id_h) (iq_1 + iq_h)
= P (Lqd_1 · iq_1 + Lqd_h · iq_1 + Lqd_1 · iq_h + Lqd_h · iq_h) (id_1 + id_h)
= P ・ Lqd_1 ・ iq_1 ・ id_1
+ P (Lqd_h · iq_1 + Lqd_1 · iq_h + Lqd_h · iq_h) id_1
+ P (Lqd_1 · iq_1 + Lqd_h · iq_1 + Lqd_1 · iq_h + Lqd_h · iq_h) id_h (9)
The first term on the right side of Equation 9 represents the fundamental wave component of the reluctance torque, and the second and third terms represent the torque ripple component. Therefore, if there is a current condition that makes the sum of the second term and the third term zero, the ripple component of the reluctance torque can be zero.
(Lqd_1 · iq_1 + Lqd_h · iq_1 + Lqd_1 · iq_h + Lqd_h · iq_h) id_h = − (Lqd_h · iq_1 + Lqd_1 · iq_h + Lqd_h · iq_h) id_1
∴id_h = − (Lqd_h · iq_1 + Lqd_1 · iq_h + Lqd_h · iq_h) id_1 / (Lqd_1 · iq_1 + Lqd_h · iq_1 + Lqd_1 · iq_h + Lqd_h · iq_h) (10)
Here, if it is assumed that the harmonic parameter of the motor parameter and current is sufficiently smaller than the fundamental wave component, Equation 10 can be approximated to the following equation.
id_h = − (Lqd_h · iq_1 + Lqd_1 · iq_h) id_1 / (Lqd_1 · iq_1) (11)
From the above calculation, it can be seen that the condition for reducing the ripple of the reluctance torque to 0 is that the harmonic component id_h of the d-axis current is set to a value represented by Equation 11.

  Thus, if the q-axis harmonic component current iq_h is controlled to the value shown in Formula 8, and the d-axis harmonic component current id_h is controlled to the value shown in Formula 11, the torque ripple of the motor can be reduced. it can.

上式において、θehは基本波ｄｑ軸座標系から見た高調波ｄhｑh軸座標系の位相であり、３相交流座標系で高調波成分が５次の場合にθeh＝−６ωe＋θeo（ここで、θeoはθe＝０とθeh＝０の位相差）である。数式８と数式１１を数式１２に代入してｄh軸電流指令値ｉdh^＊とｑh軸電流指令値ｉqh^＊を算出し、上述したように高調波電流を制御すればモーターのトルクリップルを最少にすることができる。 By the way, id_h and iq_h used here represent harmonic component currents of the d-axis and q-axis, respectively, and are converted into harmonic component currents of the dh-axis and qh-axis of the harmonic coordinate system by the following equations.

In the above equation, θeh is the phase of the harmonic dhqh axis coordinate system viewed from the fundamental wave dq axis coordinate system, and θeh = −6ωe + θeo (here, θeo) when the harmonic component is fifth order in the three-phase AC coordinate system. Is the phase difference between θe = 0 and θeh = 0. Substituting Equation 8 and Equation 11 into Equation 12 to calculate the dh-axis current command value idh ^* and qh-axis current command value iqh ^* , and controlling the harmonic current as described above minimizes the torque ripple of the motor. be able to.

FIG. 6 is a diagram showing details of the torque control unit 1A of the second embodiment. In the second embodiment, a torque control unit 1A is used instead of the torque control unit 1 shown in FIG. The torque control unit 1A calculates the d-axis current corresponding to the torque command value Te ^* and the motor rotation speed ωe from the maximum efficiency id map 1e storing the torque command value and d-axis current command value data with respect to the motor rotation speed. The command value id ^* is calculated from the table. Further, from the maximum efficiency iq map 1f in which data of the torque command value and the q-axis current command value with respect to the motor rotation speed is stored, the q-axis current command value iq ^* corresponding to the torque command value Te ^* and the motor rotation speed ωe ^. Is calculated.

The torque control unit 1A further determines the dh-axis current command corresponding to the dq-axis current command values id ^* and iq ^* from the minimum torque ripple idh map 1g storing data of the dh-axis current command value with respect to the dq-axis current command value. The value idh ^* is looked up. Similarly, the qh-axis current command value iqh ^* corresponding to the dq-axis current command value id ^* and iq ^* is obtained from the minimum torque ripple iqh map 1h in which the data of the qh-axis current command value with respect to the dq-axis current command value is stored. Perform a table lookup operation.

In the maps 1e to 1h, among the current command value combinations for making the motor torque Te coincide with the torque command value Te ^* , the fundamental wave current and the harmonics that satisfy the above formulas 8 and 11 and minimize the torque ripple. The current command value is stored. Since deviation occurs when these command values are obtained by calculation, the fundamental wave current and the harmonic current that minimize the torque ripple may be measured by experiment, and these values may be adopted as data.

According to the second embodiment, at any motor rotation speed ωe, torque Te that matches the torque command value Te ^* can be output from the motor while minimizing torque ripple.

<< Third Embodiment of the Invention >>
A third embodiment for minimizing voltage ripple will be described. The configuration of the third embodiment is the same as the configuration of the first embodiment shown in FIG. 1 except for the torque control unit 1, and the description of the overall configuration is omitted, with the focus on the differences. explain.

  FIG. 7 shows the relationship of the torque Te to the rotational speed ωe of the motor M, that is, the output characteristics of the motor M. The motor M is driven and controlled up to the maximum torque line of the thick line (1) from 0 to the base rotational speed ± ωb, and is controlled to the maximum output line of the broken line (2) when the rotational speed exceeds the base rotational speed ± ωb. The Normally, the rated current of the power element of the power conversion unit 10 is determined according to the maximum torque line (1). For example, when the rated current is 600 A, the fundamental current can flow up to 600 A. However, when the harmonic current is included in the motor current, the peak value of the motor current becomes larger than the peak value of the fundamental wave current, so the fundamental wave current must be kept lower than the rated 600A, and the maximum torque is reduced. In addition, the iron loss and copper loss increase and the efficiency becomes worse. On the other hand, if the motor voltage contains harmonic components, the peak value of the motor voltage will be higher than the peak value of the fundamental voltage, so the fundamental voltage must be kept lower than the rated voltage of the motor and power element. Due to the shortage, a predetermined current cannot flow and the output decreases.

First, the voltage ripple of the motor including spatial harmonics will be described. The circuit equation of the motor M can be expressed as follows.
vd = R · id + d (φd) / dt−ωe · φq
= R · id + d (φdm + Ld · id) / dt−ωe · Lq · iq,
vq = ωe ・ φd + R ・ iq + d (φq) / dt
= Ωe (φdm + Ld · id) + R · iq + d (Lq · iq) / dt (13)
Here, vd is a d-axis voltage, vq is a q-axis voltage, R is a phase winding resistance, φd is a d-axis armature linkage flux, φq is a q-axis armature linkage flux, and φdm is an armature linkage flux ( Magnet)), Ld is d-axis inductance, and Lq is q-axis inductance.

When Equation 13 is described by dividing the magnetic flux, inductance, and current into fundamental wave components and harmonic components, first, the d-axis voltage vd is expressed as follows.
vd = R (id_1 + id_h)
+ D {(φdm_1 + φdm_h) + (Ld_1 + Ld_h) (id_1 + id_h)} / dt
-Ωe (Lq_1 + Lq_h) (iq_1 + iq_h)
= R (id_1 + id_h)
+ D {(φdm_1 + Ld_1 · id_1) + (φdm_h + Ld_h · id_1 + Ld_1 · id_h + Ld_h · id_h)} / dt
-Ωe (Lq_1 ・ iq_1 + Lq_h ・ iq_1 + Lq_1 ・ iq_h + Lq_h ・ iq_h)
= {R · id_1 + d (φdm_1 + Ld_1 · id_1) / dt + ωe · Lq_1 · iq_1}
+ [R · id_h + d (φdm_h + Ld_h · id_1 + Ld_1 · id_h + Ld_h · id_h) / dt−ωe (Lq_h · iq_1 + Lq_1 · iq_h + Lq_h · iq_h)] (14)
In Expression 14, the first term is a fundamental wave component, and the second term is a voltage ripple component. In order to reduce the voltage ripple to 0, the second term may be set to 0.
R · id_h + d (φdm_h + Ld_h · id_1 + Ld_1 · id_h + Ld_h · id_h) / dt−ωe (Lq_h · iq_1 + Lq_1 · iq_h + Lq_h · iq_h) = 0 (15)
For that purpose, it is necessary to set all three terms of Formula 15 to 0. Normally, however, the first term is so small that it can be ignored as compared with the second and third terms. A condition for deriving 0 is derived. First, the following equation is obtained from the condition for setting the second term to zero.
φdm_h + Ld_h · id_1 + (Ld_1 + Ld_h) id_h = const,
∴id_h = − {(φdm_h + Ld_h · id_1) + const} / (Ld_1 + Ld_h) (16)
Further, the following equation is obtained from the condition for setting the third term to zero.
Lq_h · iq_1 + Lq_1 · iq_h + Lq_h · iq_h = 0
∴iq_h = -Lq_h · iq_1 / (Lq_1 + Lq_h) (17)

  As described above, in order to reduce the ripple of the d-axis voltage vd to 0, the harmonic components id_h and iq_h of the dq-axis current may be controlled so as to have the values shown in Equations 16 and 17.

On the other hand, when Equation 13 is described by dividing magnetic flux, inductance, and current into a fundamental wave component and a harmonic component, the q-axis voltage vq is expressed as follows.
vq = ωe {φdm_1 + φdm_h + (Ld_1 + Ld_h) (id_1 + id_h)}
+ R (iq_1 + iq_h) + d (Lq_1 + Lq_h) (iq_1 + iq_h) / dt
= {Ωe (φdm_1 + Ld_1 · id_1) + R · iq_1 + d (Lq_1 · iq_1) / dt}
+ [Ωe {φdm_h + (Ld_h · id_1 + Ld_1 · id_h + Ld_h · id_h)} + R · iq_h + d (Lq_h · iq_1 + Lq_1 · iq_h + Lq_h · iq_h) / dt] (18)
In Expression 18, the first term is a fundamental wave component, and the second term is a high-order component (ripple component). In order to reduce the q-axis voltage ripple to zero, the second term may be set to zero.
ωe {φdm_h + (Ld_h · id_1 + Ld_1 · id_h + Ld_h · id_h)} + R · iq_h + d (Lq_h · iq_1 + Lq_1 · iq_h + Lq_h · iq_h) / dt = 0 (19)
For that purpose, it is necessary to set all three terms of Equation 19 to 0. Normally, however, the second term is negligibly small compared to the first and third terms. A condition for deriving 0 is derived. First, the following equation is obtained from the condition for setting the first term to zero.
φdm_h + (Ld_h · id_1 + Ld_1 · id_h + Ld_h · id_h) = 0,
∴id_h = − (φdm_h + Ld_h · id_1) / (Ld_1 + Ld_h) (20)
Further, the following equation is obtained from the condition for setting the third term to zero.
Lq_h · iq_1 + Lq_1 · iq_h + Lq_h · iq_h = const,
∴iq_h = (− Lq_h · iq_1 + const) / (Lq_1 + Lq_h) (21)

  As described above, in order to reduce the ripple of the q-axis voltage vq to 0, the harmonic components id_h and iq_h of the dq-axis current may be controlled so as to have the values shown in Expression 20 and Expression 21.

Note that if const in Expression 16 and Expression 21 is 0, Expression 16 and Expression 20, Expression 17 and Expression 21 are the same. That is, the condition for setting the ripple voltage of the d-axis voltage vd to 0 and the condition for setting the ripple voltage of the q-axis voltage vq to 0 can be made the same. Both can be set to zero.
id_h = − (φdm_h + Ld_h · id_1) / Ld_1,
iq_h = −Lq_h · iq_1 / Lq_1 (22)
That is, the voltage ripple can be reduced by controlling the d-axis harmonic current id_h and the q-axis harmonic current iq_h in the fundamental wave coordinate system dq to be the values represented by Equation 22. The harmonic currents id_h and iq_h in the fundamental wave coordinate system dq can be converted into the dh-axis harmonic current idh and the qh-axis harmonic current iqh in the harmonic coordinate system dhqh by the above equation 12. Therefore, if the dh-axis current command value idh ^* and the qh-axis current command value iqh ^* are calculated by substituting the formula 22 into the formula 12, and the harmonic current is controlled as described above, the voltage ripple can be minimized. .

FIG. 8 is a diagram illustrating details of the torque control unit 1B according to the third embodiment. In the third embodiment, a torque control unit 1B is used instead of the torque control unit 1 shown in FIG. The torque control unit 1B obtains the d-axis current corresponding to the torque command value Te ^* and the motor rotation speed ωe from the maximum efficiency id map 1e storing the torque command value and d-axis current command value data with respect to the motor rotation speed. The command value id ^* is calculated from the table. Further, from the maximum efficiency iq map 1f in which data of the torque command value and the q-axis current command value with respect to the motor rotation speed is stored, the q-axis current command value iq ^* corresponding to the torque command value Te ^* and the motor rotation speed ωe ^. Is calculated.

The torque control unit 1B further determines the dh-axis current command corresponding to the dq-axis current command values id ^* and iq ^* from the minimum voltage ripple idh map 1i that stores the data of the dh-axis current command value with respect to the dq-axis current command value. The value idh ^* is looked up. Similarly, the qh-axis current command value iqh ^* corresponding to the dq-axis current command values id ^* and iq ^* is obtained from the minimum voltage ripple iqh map 1j storing the data of the qh-axis current command value with respect to the dq-axis current command value. Perform a table lookup operation.

Maps 1e, 1f, 1i, and 1j show fundamental wave current and harmonic current command values that minimize voltage ripple among the current command value combinations for making motor torque Te coincide with torque command value Te ^*. Contains data. Since deviation occurs when these command values are obtained by calculation, the fundamental current and the harmonic current that minimize the voltage ripple may be measured by experiment, and these values may be adopted as data.

According to the third embodiment, at any motor rotation speed ωe, the torque Te that matches the torque command value Te ^* can be output from the motor while suppressing the voltage ripple to a minimum.

<< Fourth Embodiment of the Invention >>
A fourth embodiment for minimizing current ripple will be described. The configuration of the fourth embodiment is the same as the configuration of the first embodiment shown in FIG. 1 except for the torque control unit 1, and the description of the overall configuration is omitted, with the focus on the differences. explain.

FIG. 9 is a diagram illustrating details of the torque control unit 1C according to the fourth embodiment. In the fourth embodiment, a torque control unit 1C is used instead of the torque control unit 1 shown in FIG. The torque control unit 1C obtains the d-axis current corresponding to the torque command value Te ^* and the motor rotation speed ωe from the maximum efficiency id map 1e storing the torque command value and d-axis current command value data with respect to the motor rotation speed. The command value id ^* is calculated from the table. Further, from the maximum efficiency iq map 1f in which data of the torque command value and the q-axis current command value with respect to the motor rotation speed is stored, the q-axis current command value iq ^* corresponding to the torque command value Te ^* and the motor rotation speed ωe ^. Is calculated.

On the other hand, the torque control unit 1C sets both the dh-axis current command value idh ^* and the qh-axis current command value iqh ^* to 0. As a result, the harmonic current control circuits 5, 6, 8, and 9 perform control so that the dh-axis current idh and the qh-axis current iqh of the harmonic coordinate system dhqh are both zero.

According to the fourth embodiment, it is possible to output torque Te that matches the torque command value Te ^* from the motor while minimizing current ripple at any motor rotation speed ωe.

<< Fifth Embodiment of the Invention >>
A fifth embodiment in which the optimum fundamental wave current command value and harmonic current command value are selected according to the operating state of the motor M will be described. The configuration of the fifth embodiment is the same as the configuration of the first embodiment shown in FIG. 1 except for the torque control unit 1. The description of the overall configuration is omitted and the differences are mainly described. explain.

  FIG. 10 is a diagram illustrating details of the torque control unit 1D according to the fifth embodiment. In the fifth embodiment, a torque control unit 1D is used instead of the torque control unit 1 shown in FIG. The torque control unit 1D includes a maximum efficiency current command calculation unit 1p, a minimum torque ripple current command calculation unit 1g, a minimum voltage ripple current command calculation unit 1r, a minimum current ripple current command calculation unit 1t, an optimum command value selection unit 1u, and a changeover switch. 1v.

The highest efficiency current command calculation unit 1p calculates the fundamental current command values id ^* and iq ^* and the harmonic current command values idh ^* and iqh ^* that maximize the efficiency. The minimum torque ripple current command calculation unit 1g calculates the fundamental current command values id ^* and iq ^* and the harmonic current command values idh ^* and iqh ^* that minimize the torque ripple. The minimum voltage ripple current command calculation unit 1r calculates the fundamental current command values id ^* and iq ^* and the harmonic current command values idh ^* and iqh ^* that minimize the voltage ripple. The minimum current ripple current command calculation unit 1t calculates the fundamental current command values id ^* and iq ^* and the harmonic current command values idh ^* and iqh ^* that minimize the current ripple.

  The optimum command value selection unit 1u is optimally selected from the current command values calculated by the current command calculation units 1p, 1q, 1r, and 1t according to the operation state of the motor M such as the rotational speed ωe and torque Te of the motor M. A current command value is selected, and the changeover switch 1v is switched. The torque Te of the motor M may be obtained by calculation using, for example, the above-described formulas 1 and 4 or may be measured by installing a torque detector.

  The operation of the optimum command value selection unit 1u will be described with reference to FIG. FIG. 11 shows only the first quadrant of the output characteristics of the motor M shown in FIG. The operation in the second quadrant to the fourth quadrant is the same as the operation in the first quadrant, and the description thereof is omitted.

  In FIG. 11, the motor current is larger in the region (6) near the maximum torque line (1) than in the other regions (3) to (5), and the motor current is close to the rated current of the power element of the power conversion unit 10. Become. When the operating point determined by the rotational speed ωe of the motor M and the torque Te is in the region (6), that is, when the difference between the motor torque Te and the maximum torque is less than a predetermined value and the motor torque Te is close to the maximum value, the minimum By selecting the current command value calculated by the current ripple current command calculation unit 1t and suppressing the current ripple of the motor M to the minimum, the peak value of the motor current is kept lower than the rated current of the power element.

  Further, in the region (5) near the maximum output line (2), it is necessary to apply a large voltage to the motor M as described above, so the DC bus voltage (inverter DC link voltage) and the motor voltages vu, vv, vw. The difference with is small. Therefore, when the operating point determined by the rotational speed ωe and torque Te of the motor M is in the region (5), that is, when the difference between the motor output and the maximum output is less than a predetermined value and the motor output is close to the maximum value, the minimum By selecting the current command value calculated by the voltage ripple current command calculation unit 1r and suppressing the voltage ripple of the motor M to the minimum, the peak value of the motor voltage becomes lower than the voltage voltage of the power element, and the ripple Prevents motor voltage drop due to voltage.

  Further, in the region (4) where both the rotational speed ωe and the torque Te of the motor M are low, the influence of torque ripple appears greatly. Therefore, the current command value calculated by the minimum torque ripple current command calculation unit 1g is selected, and the motor M By minimizing the torque ripple, the influence caused by the torque ripple, for example, the vibration and noise of the vehicle is reduced, thereby reducing the passenger discomfort.

  When the operating point determined by the rotational speed ωe and torque Te of the motor M is in the region (3), the current command value calculated by the maximum efficiency current command calculation unit 1p that maximizes the efficiency is selected to maximize the efficiency. Thus, the power consumption of the motor M is reduced.

  As described above, according to the fifth embodiment, the motor M can be driven and controlled by selecting an optimum current command value corresponding to the operating state of the motor M.

In each of the embodiments described above, in the torque control units 1, 1A, 1B, and 1C, the dq-axis fundamental wave current command values id ^* , iq ^*, and dhqh-axis are based on the torque command value Te ^* and the motor rotational speed ωe. The example of calculating the harmonic current command values idh ^* and iqh ^* has been shown. However, when the motor is used in the speed range from 0 to the base rotational speed ωb shown in FIG. 7, that is, only in the constant torque control region. For (constant torque control), the dq-axis fundamental wave current command values id ^* and iq ^* and the dhqh-axis harmonic current command values idh ^* and iqh ^* are calculated based only on the torque command value Te ^* . That is, a current command value map with respect to the torque command value is set in advance, and the current command values id ^* , iq ^* , idh ^* , iqh ^* corresponding to the torque command value Te ^* are subjected to a table calculation.

  The present invention can also be applied to AC motors such as synchronous motors and induction motors. In the case of an induction motor, a known magnetic flux estimator for estimating the direction of magnetic flux is provided, the coordinate system rotating in synchronization with the estimated direction of the fundamental wave component of the magnetic flux is a dq coordinate system, and the harmonic order component of the magnetic flux is A coordinate system that rotates in synchronization with the estimated direction is defined as a dhqh coordinate system.

It is a figure which shows the structure of 1st Embodiment. It is a figure which shows the armature interlinkage magnetic flux (U-phase winding) which the magnet of an IPM motor forms when there is no space harmonic. It is a figure which shows the armature interlinkage magnetic flux (U-phase winding) which the magnet of an IPM motor forms when a 5th-order space harmonic exists. It is a figure which shows the relationship between a harmonic current component and total efficiency at the time of making dq axis current id and iq which are fundamental wave current components constant. It is a figure which shows the detailed structure of the torque control part of 1st Embodiment. It is a figure which shows the detailed structure of the torque control part of 2nd Embodiment. It is a figure which shows the output characteristic of a motor. It is a figure which shows the detailed structure of the torque control part of 3rd Embodiment. It is a figure which shows the detailed structure of the torque control part of 4th Embodiment. It is a figure which shows the detailed structure of the torque control part of 5th Embodiment. It is a figure for demonstrating selection operation | movement of the optimal electric current command value according to the operation state of a motor. It is a figure which shows the structure of the control apparatus of the conventional three-phase alternating current motor. It is a figure which shows the structure of an IPM motor. It is a figure which shows the structure of a SPM motor.

Explanation of symbols

1 Torque control unit 1a Maximum efficiency d-axis current command value map 1b Maximum efficiency q-axis current command value map 1c Maximum efficiency dh-axis current command value map 1d Maximum efficiency qh-axis current command value map 1e Maximum efficiency d-axis current command value map 1f Maximum efficiency q-axis current command value map 1g Minimum torque ripple dh-axis current command value map 1h Minimum torque ripple qh-axis current command value map 1i Minimum voltage ripple dh-axis current command value map 1j Minimum voltage ripple qh-axis current command value map 1p Maximum Efficiency current command calculation unit 1q Minimum torque ripple current command calculation unit 1r Minimum voltage ripple current command calculation unit 1t Minimum current ripple current command calculation unit 2 Fundamental wave current control unit 3 Adder 4 dq / 3-phase conversion unit 5 3 phase / dq Conversion unit 6 Harmonic current control unit 7 dhqh / dq conversion unit 8 High pass filter 9 dq / dhqh conversion unit 10 Electric power Conversion units 11 and 12 Current sensor 13 Phase velocity calculation unit

Claims (12)

Fundamental wave current command value determining means for determining a fundamental current command value of the motor current based on at least the torque command value of the AC motor;
Based on the torque command value of at least AC motor, a harmonic current command value determining means for determining a harmonic current command value of the motor current,
Current detecting means for detecting an actual current flowing through the AC motor;
Fundamental wave control command value determining means for determining a fundamental wave control command value for making the actual current detected by the current detection means coincide with the fundamental wave current command value determined by the fundamental wave current command value determining means; ,
Harmonic component detection means for detecting the harmonic component of the actual current detected by the current detection means;
Harmonics for determining a harmonic control command value for matching the harmonic component of the motor current detected by the harmonic component detection means with the harmonic current command value determined by the harmonic current command value determination means Control command value determining means;
Motor driving means for driving the AC motor based on the fundamental wave control command value determined by the fundamental wave control command value determining means and the harmonic control command value determined by the harmonic control command value determining means And a motor control device. The motor control device according to claim 1,
The fundamental wave current command value determining means determines a fundamental current command value in a dq coordinate system that rotates in synchronization with the fundamental wave component of the armature flux linkage,
The harmonic current command value determining means determines a harmonic current command value in a dhqh coordinate system that rotates in synchronization with a harmonic order component of an armature flux linkage. In the motor control device according to claim 1 or 2,
The fundamental wave control command value determining means is a fundamental for matching the fundamental wave component of the motor current with the fundamental wave current command value in a dq coordinate system that rotates in synchronization with the fundamental wave component of the armature flux linkage. Determine the wave control command value,
The harmonic control command value determining means is for making the harmonic component of the motor current coincide with the harmonic current command value in a dhqh coordinate system that rotates in synchronization with the harmonic order component of the armature linkage flux. A motor control device that determines a harmonic control command value. In the motor control device according to any one of claims 1 to 3,
The fundamental wave current command value determining means and the harmonic current command value determining means are configured to set a fundamental wave current command value and a harmonic current command value that maximize motor efficiency while matching the motor torque with the torque command value. A motor control device characterized by determining each. In the motor control device according to any one of claims 1 to 3,
The fundamental wave current command value determining means and the harmonic current command value determining means are configured to set a fundamental wave current command value and a harmonic current command value that minimize torque ripple while matching motor torque to the torque command value, respectively. A motor control device characterized by determining. In the motor control device according to any one of claims 1 to 3,
The fundamental wave current command value determining means and the harmonic current command value determining means are configured to set a fundamental wave current command value and a harmonic current command value that minimize voltage ripple while matching the motor torque with the torque command value, respectively. A motor control device characterized by determining. In the motor control device according to any one of claims 1 to 3,
The fundamental wave current command value determining means and the harmonic current command value determining means are configured to set a fundamental wave current command value and a harmonic current command value that minimize current ripple while matching motor torque to the torque command value, respectively. A motor control device characterized by determining. In the motor control device according to any one of claims 1 to 3,
The fundamental current command value determining means and the harmonic current command value determining means are a fundamental current command value, a harmonic current command value, and a motor torque that maximize motor efficiency while making the motor torque coincide with the torque command value. The fundamental wave current command value and the harmonic current command value that minimize the torque ripple while matching the torque command value, and the fundamental wave current command value that minimizes the voltage ripple while matching the motor torque to the torque command value; Determine the harmonic current command value and the harmonic current command value to minimize the current ripple while matching the motor torque with the torque command value, respectively.
Operation state detection means for detecting the operation state of the motor;
The optimum current command value corresponding to the motor operating state is selected from the fundamental wave current command value and the harmonic current command value determined by the fundamental current command value determining means and the harmonic current command value determining means. The motor control device further comprising a current command value selection means for performing the operation. The motor control device according to claim 8, wherein
The current command value selection means, when a motor operating state within a predetermined region where the motor torque is close to the maximum value is detected, a fundamental current command that minimizes current ripple while matching the motor torque with the torque command value. A motor control device that selects a value and a harmonic current command value. The motor control device according to claim 8, wherein
The current command value selection means is a fundamental wave that minimizes torque ripple while matching the motor torque with the torque command value when a motor operating state within a predetermined range in which both the motor torque and the motor rotation speed are low is detected. A motor control device that selects a current command value and a harmonic current command value. The motor control device according to claim 8, wherein
The current command value selection means is a fundamental current command for minimizing voltage ripple while matching the motor torque with the torque command value when a motor operating state within a predetermined region where the motor output is close to the maximum value is detected. A motor control device that selects a value and a harmonic current command value. The motor control device according to claim 8, wherein
The current command value selecting means detects a motor operating state in which the motor torque and the motor output are not within the predetermined range close to their maximum values, and both the motor torque and the motor rotation speed are not within the predetermined range. Is a motor control device that selects a fundamental current command value and a harmonic current command value that maximize motor efficiency while making the motor torque coincide with the torque command value.

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