JP6998717B2 - Variable magnetic force motor control method and control device - Google Patents

Description

The present invention relates to a control method and a control device for a variable magnetic force motor.

Conventionally, a drive system for a variable magnetic flux (variable magnetic flux) motor that changes the magnetic force of a permanent magnet by a magnetization current supplied from an inverter to a stator winding is known (see Patent Document 1). This drive system has a booster circuit that boosts the DC voltage, which is operated during magnetism control, and the boosted voltage is input to the inverter to compensate for the voltage shortage during magnetism control. Further, the variable magnetic force motor has a characteristic that the loss at the time of driving can be reduced and the motor efficiency can be improved by changing the magnetic force of the permanent magnet according to the operating state of the vehicle.

Japanese Unexamined Patent Publication No. 2007-240833

However, when the operation of the booster circuit is stopped except during magnetization control, a loss occurs due to the consumption of electric power by the elements constituting the booster circuit. Therefore, there is a problem that the loss reduction margin at the time of driving due to the characteristics of the variable magnetic force motor is offset, and as a result, the efficiency of the driving system as a whole is not improved.

The present invention suppresses the voltage required for demagnetization control and eliminates the need for an additional booster circuit to improve the efficiency of the entire system and improve the torque response after the demagnetization control is completed. It is an object of the present invention to provide a control method of a variable magnetic force motor which can be performed.

The control method of the variable magnetic force motor according to the present invention is a control method of the variable magnetic force motor that changes the magnetic force of the permanent magnet during driving, and the current feedback PI control that feeds back the current supplied to the variable magnetic force motor is used to meet the driving requirement. The PI control step that controls the variable magnetic force motor so as to output the target torque set based on this, and the command interlinkage magnetic flux vector that outputs the torque equivalent to the target torque are calculated, and the command chain is controlled by feedback. Includes a feedback control step, which controls the variable magnetic force motor to realize an AC magnetic flux vector. Then, the PI control step and the feedforward control step are switched according to the operating state of the variable magnetic force motor. The operating state referred to here includes a state in which load operation control for outputting a target torque is executed and a state in which demagnetization control for changing the magnetic force of a permanent magnet is executed, and demagnetization control is executed. At that time, the step is switched to the feedforward control step, and when the demagnetization control is completed and the load operation control is executed, the step is switched to the PI control step. The target interlinkage magnetic flux vector that outputs the target torque when the permanent magnet reaches the target demagnetization amount is calculated, the command interlinkage magnetic flux vector is calculated using the equation (1) described later, and in the feed forward control step. After completing the demagnetization to achieve the target demagnetization amount, the variable magnetic force motor is controlled so as to realize the command interlinkage magnetic flux vector.

According to the present invention, the voltage required for demagnetization control can be suppressed by switching between the PI control step and the feedforward control step according to the operating state, so that an additional booster circuit is not required and the entire system can be used. Efficiency can be improved. Further, since the PI control step and the feedforward control step are controlled so as to output the same torque, the torque response after the completion of the demagnetization control can be improved.

FIG. 1 is a control block diagram showing a configuration example of a control device for a variable magnetic force motor according to the first embodiment. FIG. 2 is a diagram schematically showing an interlinkage magnetic flux vector on αβ coordinates when controlling a variable magnetic force motor in the first embodiment. FIG. 3 is a control block diagram showing a configuration example of the current FB controller. FIG. 4 is a control block diagram showing another configuration example of the current FB controller. FIG. 5 is a schematic diagram showing the loci of operating points in the dq coordinate system when the variable magnetic force motor is controlled by the interlinkage magnetic flux vector in the second embodiment. FIG. 6 is a diagram schematically showing the interlinkage magnetic flux vector on the αβ coordinates when controlling the variable magnetic force motor in the third embodiment. FIG. 7 is a diagram for explaining an intermediate interlinkage magnetic flux vector in the dq coordinate system.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[First Embodiment]
FIG. 1 is a control block diagram showing a configuration example of a control device 100 for a variable magnetic force motor according to the first embodiment of the present invention.

The variable magnetic force motor control device 100 (hereinafter referred to as “motor control device 100”) drives the variable magnetic force motor 6 and controls the demagnetization of the permanent magnet included in the variable magnetic force motor 6. The motor control device 100 is mounted on, for example, a hybrid vehicle or an electric vehicle equipped with a variable magnetic force motor 6.

The motor control device 100 of the present embodiment includes a vector controller 1, a current feedback controller 20, a dq axis / UVW phase converter 3, a switch 4, a PWM voltage inverter 5, and a UVW phase / dq axis conversion. It includes a device 7, a magnetic flux observer 8, and an interlinkage magnetic flux feed forward controller 10. The control target of the motor control device of this embodiment is the variable magnetic force motor 6.

The motor control device 100 is composed of one or a plurality of controllers. The controller is composed of, for example, a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), and an input / output interface (I / O interface). The controller constituting the motor control device 100 is programmed to realize each function described below.

The variable magnetic force motor 6 (hereinafter, simply referred to as “motor 6”) to be controlled by the motor control device 100 is a variable magnetic force motor composed of a stator having a stator winding and a rotor having a permanent magnet embedded therein. Is. The permanent magnet embedded in the rotor has the property that its magnetic force can be changed by the magnetic field formed by the current flowing through the stator winding when the motor 6 is rotating (driving). .. That is, the permanent magnet included in the variable magnetic force motor 6 is magnetized or demagnetized by the current flowing in the winding of the motor 6, and its residual magnetic flux density changes. Permanent magnets with such characteristics are also called low coercive magnets, and the coercive force is 1 / of the holding power of permanent magnets (high coercive magnets) used in general IPM (Interior Permanent Magnet) motors. It is about 5.

The motor 6 of the present embodiment is driven by supplying AC currents iu, iv, and iwa to the stator windings of each of the U-phase, V-phase, and W-phase. The motor 6 is provided with a rotor position detector (not shown). The rotor position detector detects the position of the rotor of the motor 6 at a predetermined cycle, so that the electric angle (rotor phase) θ of the rotor is calculated. The calculated rotor phase θ is output to the UVW phase / dq axis converter 7 and the interlinkage magnetic flux feedforward controller 10. The rotor position detector is, for example, a resolver or an encoder.

Further, the motor control device 100 includes a rotation speed calculator (not shown), and calculates the rotor rotation speed ω of the motor 6 from the amount of change in the rotor phase θ acquired in a predetermined cycle per unit time. The calculated rotor rotation speed ω is output to the vector controller 1, the magnetic flux observer 8, and the interlinkage magnetic flux feedforward controller 10.

The vector controller 1 acquires a torque command value T ^* that determines the driving force of the motor 6 from a controller (not shown) or a functional unit (not shown) of the motor control device 100. In the controller (not shown), the torque command value T ^* is calculated according to the driving state of the vehicle. For example, as the amount of depression of the accelerator pedal provided on the vehicle increases, the torque command value T ^* output to the vector controller 1 increases. That is, the torque command value T ^* is a target torque determined based on the driving request of the driver. In the following, the control for causing the variable magnetic force motor 6 to achieve the target torque is referred to as "load operation control", and the operating state of the variable magnetic force motor 6 in the control section by the load operation control is referred to as "first operating state". Refer to.

The vector controller 1 sets the d-axis current command value id ^* and the q-axis current command value iq ^* representing the current vector of the current supplied to the motor 6 based on the torque command value T ^* and the rotor rotation speed ω. Calculate. In the present embodiment, the vector controller 1 is a vector in which a d-axis current command value and a q-axis current command value are associated with each other for each operating point specified by the torque command value T ^* of the motor 6 and the rotor rotation speed ω. The control map is stored in advance. This vector control map is appropriately set according to experimental data and the like.

Then, when the vector controller 1 acquires the torque command value T ^* for the motor 6 and the rotor rotation speed ω, the vector controller 1 refers to the vector control map and the operating point specified by the torque command value T ^* and the rotor rotation speed ω. The d-axis current command value id ^* and the q-axis current command value iq ^* associated with the above are calculated and output to the current feedback controller 20. In this specification, the d-axis component and the q-axis component of the current supplied to the motor 6 are referred to as a d-axis current and a q-axis current, respectively. The vector controller 1 does not necessarily have to store the vector control map in advance, and may obtain the d-axis current command value id ^* and the q-axis current command value iq ^* by calculation.

Further, the vector controller 1 of the present embodiment commands the amount of demagnetization to the permanent magnet in order to control the permanent magnet included in the motor 6 to a magnetized state suitable for achieving a desired vehicle speed and torque. The magnetizing amount command value MS ^* is calculated and output to the interlinkage magnetic flux feed forward controller 10, which will be described later.

The vector controller 1 calculates the magnetizing amount command value MS ^* by, for example, selecting a loss map suitable for achieving a desired vehicle speed and torque from a plurality of loss maps stored in advance. Can be done. Each loss map shows the loss characteristics corresponding to the magnetized state of the permanent magnets of the rotor in relation to vehicle speed and torque. Therefore, the magnetization state with the least loss to realize the torque command value T ^* is selected from the plurality of loss maps stored for each magnetization state, and the amount of demagnetization required to achieve the magnetization state is determined. Can be calculated. The vector controller 1 of the present embodiment calculates a magnetizing amount command value MS ^* for controlling the permanent magnet included in the motor 6 to an ideal magnetization state for achieving a desired vehicle speed and torque from a loss map. , Output to the interlinkage magnetic flux feed forward controller 10. The demagnetization control for the motor 6 by the interlinkage magnetic flux feedforward controller 10, which is executed according to the magnetism amount command value MS ^* , will be described later. The vector controller 1 does not necessarily have to store the vector control map in advance, and may obtain the magnetizing amount command value MS ^* by calculation.

The current feedback controller 20 (hereinafter referred to as "current FB controller 20") has a d-axis whose positive direction is from the S pole to the N pole of the permanent magnet and orthogonal to the d-axis, and the rotation direction of the rotor is set. In the dq-axis coordinate system, which is a rotor synchronous coordinate system having a positive q-axis, current vector control for converging the current vector to a target value is executed. That is, the current FB controller 20 of the present embodiment has the _d -axis current detection value id and the q-axis current detection value i obtained by converting the three-phase alternating currents iu, iv, and iwa supplied to the motor 6 into dq-axis coordinates. The d-axis voltage command value V _d ^* and the q-axis voltage command value V _q ^* are calculated so that _q converges on the _d -axis current command value id ^* and the q-axis current command value i _q ^* , respectively.

FIG. 2 is a diagram showing a control block of the current FB controller 20. The current FB controller 20 includes PI controllers 21 and 22, and has a d-axis current command value id ^* and a q-axis current command value i _q ^* , and a _d -axis current detection value _id and a q-axis current detection value i _q . The d-axis voltage command value v _d ^* and the q-axis voltage command value v _q ^* are calculated by performing proportional calculation and integral calculation for the deviations from and. The calculated d-axis voltage command value v _d ^* and q-axis voltage command value v _q ^* are output to the dq-axis / uvw phase converter 3. The function of the reset signal Ssw input to the PI controllers 21 and 22 will be described later.

The above-mentioned d-axis voltage command value V _d ^* and q-axis voltage command value V _q ^* calculated by the current FB controller 20 are for generating a desired torque in the motor 6 at the time of load operation control based on the traveling request. It is a voltage command value calculated in. On the other hand, at the time of magnetization control for magnetizing or demagnetizing the permanent magnet, a voltage command value (Vu *,) for generating a desired magnetization current in the motor 6 by the interlinkage magnetic flux feed forward controller 10 described later. Vv *, Vw *) is calculated.

That is, the motor control device 100 of the present embodiment controls the motor 6 in order to magnetize or demagnetize the permanent magnet and the control section (first operating state) that controls the motor 6 during the load operation based on the traveling request. The motor 6 is controlled so that a desired torque can be output in a magnetized state with less loss while going back and forth between the control section (second operating state). The control main body in the first operating state is the current FB controller 20, and the control main body in the second operating state is the interlinkage magnetic flux feedforward controller 10. The details of the control of the second operating state and the details of the control of the first operating state when switching from the second operating state to the first operating state will be described later.

The dq-axis / UVW phase converter 3 uses the d-axis voltage command value V _d ^* and the q-axis voltage command value V _q ^* calculated by the current FB controller 20 as the U-phase voltage command value, which is a three-phase voltage command value. Converts to V _u ^* , V-phase voltage command value V _v ^* , and W-phase voltage command value V _w ^* .

The switch 4 is a three-phase voltage command value Vu ^* , Vv ^* , Vw ^* in the first operating state output from the dq-axis / UVW phase converter 3 (hereinafter referred to as “first three-phase voltage command value”). And the three-phase voltage command values Vu ^* , Vv ^* , Vw ^* (hereinafter referred to as "second three-phase voltage command value") in the second operating state output from the interlinkage magnetic flux feed forward controller 10 described later. Is switched according to the operating condition.

More specifically, the switch 4 outputs the input first-phase voltage command value to the PWM voltage inverter 5 in the control section in which the load operation is performed based on the travel request. On the other hand, in the control section where the permanent magnet of the motor 6 is demagnetized, the output value output to the PWM voltage inverter 5 is set to the first third phase in response to the switching command Ssw output from the interlinkage magnetic flux feed forward controller 10. Switch from the voltage command value to the second three-phase voltage command value.

The PWM voltage inverter 5 converts the DC voltage output from a power source (not shown) into the PWM voltages Vu, Vv, and Vw of each phase based on the input first or second three-phase voltage command value, and converts the DC voltage. The PWM voltages Vu, Vv, and Vw of each phase are output to each phase of the motor 6. As a result, the three-phase alternating currents iu, iv, and iwa are supplied to the stator windings of each phase of the motor 6, respectively.

The UVW phase / dq-axis converter 7 converts the three-phase AC currents iu, iv, and iwa into the d-axis real current id and the q-axis real current iq based on the rotor phase θ, and turns the current FB controller 20 into a current FB controller 20. It feeds back and outputs to the magnetic flux observer 8.

The magnetic flux observer 8 has a d-axis real current id and a q-axis real current iq, a rotor rotation speed ω, and a d-axis voltage command value v _d ^* and a q-axis voltage command value v _q ^* output from the current FB controller 20. Based on, the estimated value λ of the current interlinkage magnetic flux vector is calculated. As the calculation method, a conventionally known method may be used. The calculated interlinkage magnetic flux vector estimated value λ is output to the interlinkage magnetic flux feedforward controller 10.

The interlinkage magnetic flux feedforward controller 10 (hereinafter referred to as “interlinkage magnetic flux FF controller 10”) is an FF used to control the magnetization state (magnetization demagnetization amount) of the motor 6 in the above-mentioned second operating state. It is a controller. The interlinkage magnetic flux FF controller 10 calculates a demagnetization demagnetization demagnetization magnetic flux vector λmag for achieving a desired demagnetization amount, and outputs a target torque in a state where the motor 6 achieves the demagnetization amount. The target interlinkage magnetic flux vector λt is calculated, and further, the command interlinkage magnetic flux vector λc from the demagnetized demagnetization interlinkage flux vector λmag to the target interlinkage magnetic flux vector λt is calculated. Since magnetization and demagnetization have the same control, the following description is based on the premise of magnetism control.

FIG. 3 is a diagram schematically showing an interlinkage magnetic flux vector on αβ coordinates when the motor control device 100 of the present embodiment controls the motor 6 in the second operating state. The αβ coordinates shown in FIG. 3 coincide with the center (U axis) of the U-phase coil of the motor 6, and the α axis and the α axis whose direction is positive when the magnet magnetic flux is strengthened when they coincide with the d axis of the rotor. It is a Cartesian coordinate system composed of a β axis rotated by 90 ° in the electric angle in the rotor rotation direction. The alternate long and short dash line in the figure indicates the position of the d-axis of the rotor. As described above, the d-axis of the rotor coincides with the α-axis at the start of magnetism, but the rotor rotates during the magnetizing operation. Therefore, at the completion of the magnetizing operation, for example, the β-axis as shown in the figure. Move to a position closer to.

The MG point shown in the figure represents the target magnetism amount commanded by the magnetism amount command value MS ^* . That is, the interlinkage magnetic flux vector 101 drawn to the MG point is the interlinkage magnetic flux vector λmag at the time of magnetism. The interlinkage magnetic flux vector λmag according to the magnetism amount command value MS ^* stores, for example, a map in which the magnetism amount is associated with the interlinkage magnetic flux vector that achieves the magnetism amount, and the map is stored. Calculated by reference.

The target interlinkage magnetic flux vector 102 outputs a target torque (torque command value T ^* ) in a state where the motor 6 is magnetized to the target magnetism amount commanded by the magnetism amount command value MS ^* . It represents the vector λt. The target interlinkage magnetic flux vector λt is calculated by, for example, storing a map in which a magnetized state and an interlinkage magnetic flux vector that outputs a predetermined torque according to the magnetized state are associated with each other in advance and referring to the map. To.

The interlinkage magnetic flux vector 103 is a command interlinkage magnetic flux vector λc from the MG point to the target interlinkage magnetic flux vector λt. The command interlinkage magnetic flux vector λc is an interlinkage magnetic flux vector on the αβ coordinate to which the motor 6 in the present embodiment is applied, changes the permanent magnet to a desired magnetization state, and performs a second operation after magnetization is completed. It is an interlinkage magnetic flux vector for quickly converging the torque of the motor 6 to the target torque when switching from the state to the first operating state. The command interlinkage magnetic flux vector λc is calculated using the following equation (1).

However, λcomand is the command interlinkage magnetic flux vector λc, λtarget is the target interlinkage magnetic flux vector λt, λmagnetize is the demagnetized interlinkage magnetic flux vector estimated value λmag, and Vmax is the maximum of the PWM voltage inverter 5. The output voltage and ω indicate the rotor rotation speed ω, respectively.

When the command interlinkage magnetic flux vector λc is calculated by the above equation (1), the interlinkage magnetic flux FF controller 10 receives the second three-phase voltage command values Vu ^* , Vv ^* , and the command interlinkage magnetic flux vector λc to realize the command interlinkage magnetic flux vector λc. Vw ^* is calculated and output to the switch 4, and the switching period command value Tsw for commanding the application time (switching period) of the second three-phase voltage command value is output to the PWM voltage inverter 5. That is, the interlinkage magnetic flux FF controller 10 realizes the command interlinkage magnetic flux vector λc by controlling the amplitude and the phase component (switching period) of the voltage applied to the motor 6.

Further, the interlinkage magnetic flux FF controller 10 sends a switching command Sw for switching the voltage command value output to the PWM voltage inverter 5 from the first three-phase voltage command value to the second three-phase voltage command value to the switch 4. Output. The switch 4 to which the switching command Sw is input switches the voltage command value output to the PWM voltage inverter 5 from the first three-phase voltage command value to the second three-phase voltage command value.

Then, the PWM voltage inverter 5 has a command interlinkage magnetic flux vector based on the input second and third phase voltage command values Vu ^* , Vv ^* , Vw ^* and the switching period command value Tsw for commanding the switching cycle. PWM voltages Vu, Vv, and Vw that realize λc are applied to each phase of the motor 6.

At this time, the command interlinkage magnetic flux vector λc (103) is calculated as an interlinkage magnetic flux vector that outputs the target torque according to the magnetization state magnetized to the target magnetism amount, so that magnetization including magnetization control is included. The interlinkage magnetic flux vector in the control section (second operating state) is controlled to output a torque (target torque) corresponding to the torque command value T ^* when the magnetization control section is completed. That is, the interlinkage magnetic flux FF controller 10 realizes the command interlinkage magnetic flux vector λc with the second three-phase voltage command values Vu ^* , Vv ^* , and Vw ^* in the magnetization control section, so that the command interlinkage magnetic flux vector λc is on the αβ coordinates. The operating point of the motor in the above is moved from the MG point that changes the permanent magnet to the desired magnetization state to the position where the target torque based on the torque command value T ^* is output.

Then, the interlinkage magnetic flux FF controller 10 outputs the switching command Sw to the switching device 4 when the magnetizing control is completed. As a result, the voltage command value input to the PWM voltage inverter 5 is switched from the second three-phase voltage command value to the first three-phase voltage command value. In other words, the main body that controls the motor 6 switches from the interlinkage magnetic flux FF controller 10 to the current FB controller 20.

At this time, the current command values id ^* and iq ^* for the current FB controller 20 to output the target torque corresponding to the torque command value T ^* by the motor 6 in the magnetized state magnetized by the above magnetizing control. Enter. The operating point of the motor is at a position where the target torque based on the torque command value T ^* can be output as described above. Therefore, it is possible to quickly shift from the magnetism control by the interlinkage magnetic flux FF controller 10 to the load operation control by the current FB controller 20.

However, even in the second operating state during magnetization control, the current FB controller 20 calculates the dq-axis voltage command values Vd ^* and Vq ^* by PI control. Therefore, during the period in which the interlinkage magnetic flux FF controller 10 is performing the interlinkage magnetic flux vector control, the integrators of the PI controllers 21 and 22 included in the current FB controller 20 have current command values id ^* and iq ^*. And the deviation between the dq axis actual current id and iq are accumulated. Then, the first three-phase voltage command values Vu ^* , Vv ^* , and Vw ^* in the motor control mainly composed of the current FB controller 20 are desired to output the target torque by the deviation accumulated in the integrator. It deviates from the value. That is, if the main body that controls the motor 6 is simply switched from the interlinkage magnetic flux FF controller 10 to the current FB controller 20 after the magnetism control is completed, the target torque is due to the deviation accumulated in the integrator during the magnetization control period. Not only can it not output torques that match, but it can also cause overcurrent.

Therefore, in the present embodiment, when the control subject is switched from the interlinkage magnetic flux FF controller 10 to the current FB controller 20, the integrators of the PI controllers 21 and 22 of the current FB controller 20 are reset. More specifically, the interlinkage magnetic flux FF controller 10 also outputs a switching command Sw to be output to the switching device 4 when the magnetism control is completed to the current FB controller 20 as a reset signal Sw. Then, the current FB controller 20 resets the integrator of the PI controllers 21 and 22 according to the input reset signal Sw. As a result, the deviation accumulated unnecessarily during the magnetization control period is not reflected in the load operation control, so that even if the control body switches from the interlinkage magnetic flux FF controller 10 to the current FB controller 20, the motor torque is increased. The target torque can be quickly converged without causing a torque step.

As described above, the motor control device 100 of the present embodiment switches the control main body from the current FB controller 20 to the interlinkage magnetic flux FF controller 10 at the time of magnetism control, and is loaded by the interlinkage magnetic flux FF controller 10. Magnetization control is executed separately from the operation time. Therefore, the motor control device 100 of the present embodiment does not need to perform magnetization control by the interlinkage magnetic flux FF controller 10 in synchronization with the rotation (phase) of the rotor. For this reason, for example, when the torque is weakened during high-speed rotation, it is possible to avoid a situation in which the field weakening control is performed and the magnetization control is performed at the same time, and the voltage required for the magnetization control can be suppressed. It is possible to eliminate the need for an additional booster circuit for compensating for the voltage shortage during magnetization control as in the conventional case. As a result, the overall loss when the motor 6 is controlled by the motor control device 100 can be suppressed, and the overall efficiency can be improved.

Further, by executing the magnetism control by the interlinkage magnetic flux FF controller 10, it is not necessary to synchronize the magnetic field with the rotation (phase) of the rotor during the magnetizing period, so that even when the rotor rotates at high speed, it is more effective. Magnetization can be completed reliably. That is, the motor control device 100 of the present embodiment enables magnetism demagnetization in a higher speed range than in the conventional case by executing magnetism control by the interlinkage magnetic flux FF controller 10.

Further, the current FB controller 20 of the present embodiment is configured to include, for example, as shown in FIG. 4, a dq-axis non-interference controller 23 that compensates for the velocity electromotive force generated in the d-axis and the q-axis. You may. In the dq-axis non-interference controller 23, the d-axis voltage command value Vd is obtained by subtracting the d-axis interference voltage obtained by multiplying the d-axis actual current id by the d-axis inductance ωLd from the output of the PI controller 21. ^* Calculate. Further, the q-axis interference voltage obtained by multiplying the q-axis actual current iq by the q-axis inductance ωLq is subtracted from the output of the PI controller 22, and q is added by adding the interlinkage magnetic flux ωλpm of the permanent magnet. Calculate the shaft voltage command value Vq ^* . As a result, even after the above-mentioned integrator is reset, the necessary and sufficient dq-axis voltage command values Vd ^* and Vq ^* in which the velocity electromotive force generated in the d-axis and the q-axis are compensated are output, so that the control body is chained. When switching from the cross flux FF controller 10 to the current FB controller 20, the motor torque can be quickly converged by the target torque without torque vibration. The velocity electromotive force is an electromotive force generated in proportion to the rotation speed when the rotor rotates while the stator winding is excited.

As the d-axis inductance ωLd, the q-axis inductance ωLq, and the interlinkage magnetic flux ωλpm used in the d-q-axis non-interference controller 23, either an estimated value or a fixed value may be used. However, if the estimated value is used, the dq-axis voltage command values Vd ^* and Vq ^* that more closely match the target torque can be calculated, so that the motor torque can be smoothly converged by the target torque. A known method may be used as the estimation method.

With the above configuration, the motor control device 100 generates torque vibration due to a torque step when switching to the load operation control section in normal load operation after the demagnetization control section for magnetism. It is possible to improve the time (torque responsiveness) until the target torque corresponding to the dq-axis current command values id ^* and iq ^* is output after the magnetization control is completed.

As described above, the control device 100 of the variable magnetic force motor 6 of the first embodiment is a motor control device 100 that realizes a control method of the variable magnetic force motor 6 that changes the magnetic force of the permanent magnet during driving. The motor control device 100 controls the variable magnetic flux motor 20 so as to output a target torque set based on a traveling request by current feedback PI control that feeds back the current supplied to the variable magnetic flux motor 6. And, the interlinkage magnetic flux feed forward controller that controls the variable magnetic flux motor 6 so as to realize the command interlinkage magnetic flux vector by the feed forward control by calculating the command interlinkage magnetic flux vector that outputs the torque equivalent to the target torque. Includes 10. Then, the control by the current FB controller 20 and the control by the interlinkage magnetic flux FF controller 10 are switched according to the operating state of the variable magnetic force motor 6. The above operating state includes a state in which load operation control for outputting a target torque set based on a running request is executed and a state in which demagnetization control for changing the magnetic force of a permanent magnet is executed. When the demagnetization control is executed, it is switched to the feed forward control, and when the load operation control is executed, it is switched to the current feedback PI control.

As a result, the demagnetization control can be executed separately from the current feedback PI control during load operation, so that the voltage required for the demagnetization control can be suppressed and the efficiency of the entire system can be improved. Further, since the current feedback PI control by the current FB controller 20 and the feedforward control by the interlinkage magnetic flux FF controller 10 are controlled to output the same torque, the target torque is reached after the demagnetization control is completed. Response time (torque response) can be improved.

Further, according to the control device 100 of the variable magnetic force motor of the first embodiment, the target interlinkage magnetic flux vector λt that outputs the target torque in the state where the permanent magnet reaches the target demagnetization amount is calculated, and the above equation (1). ) Is used to calculate the command interlinkage magnetic flux vector λc. Then, in the feedforward control, the variable magnetic force motor 6 is controlled so as to realize the command interlinkage magnetic flux vector λc after completing the demagnetization to achieve the target demagnetization amount. Thereby, the improvement of the torque response performance after the completion of the demagnetization control can be realized by the above equation (1).

Further, according to the control device 100 of the variable magnetic force motor 6 of the first embodiment, when the feedback control by the interlinkage magnetic flux FF controller 10 is completed, the target torque is set in a state where the permanent magnet reaches the target demagnetization amount. Switch to the current feedback PI control that is executed based on the output current command value. As a result, it is possible to shift to load operation control while utilizing the PI control used in conventional motor control while maintaining the target torque after achieving the target demagnetization, so that the target torque can be demagnetized without increasing the cost. It is possible to improve the torque response after the control is completed.

Further, according to the control device 100 of the variable magnetic force motor 6 of the first embodiment, the current feedback PI control converges the current vector to the target value in the dq coordinate system which is the d-axis and q-axis rotator synchronous coordinate system. In the current vector control, the integrated value in the current feedback PI control is reset when the feed forward control is switched to the current feedback PI control. As a result, the deviation accumulated in the integrator used in the current feedback PI control can be reset during the feedforward control period, so that the occurrence of torque vibration can be suppressed and the current vector control can be stably performed. ..

Further, according to the control device 100 of the variable magnetic force motor 6 of the first embodiment, the current feedback PI control includes non-interference control for compensating for the velocity electromotive force generated in the d-axis and the q-axis. As a result, it is possible to stably shift to the current vector control without generating torque vibration.

[Second Embodiment]
Hereinafter, the second embodiment will be described. The description of the same configuration as that of the first embodiment will be omitted.

FIG. 5 is a diagram schematically showing the locus of the operating point of the motor 6 when the motor control device 200 of the second embodiment controls the motor 6 by the interlinkage magnetic flux vector. The d-axis represents the d-axis current id, and the q-axis represents the q-axis current iq. The semicircle represented by the solid line indicates the rated current circle, and the inside of this circle indicates the region where the operating point of the motor 6 can be controlled. The region on the right side from the intersection of the d-axis and the q-axis is the range of strong field control, and the region on the left side is the range of weak field control.

Point F in the figure indicates an operating point when magnetization control is completed. The point F is a point where the target interlinkage magnetic flux vector λt substantially coincides with the target operating point in the first embodiment.

The dotted line in the figure is an equal torque line. When the operating point of the motor 6 is on the line, torque of the same magnitude can be output. That is, the line is an operating point capable of outputting the target torque described in the first embodiment. The locus of the isotorque line shown in the figure is an example in this embodiment and differs depending on the motor design (torque-oriented, rotation speed-oriented, etc.), and is therefore appropriately set depending on how the motor 6 is designed. It's okay.

The point H is the highest efficiency point with the highest efficiency at the operating point where the target torque can be output.

Here, from the viewpoint of improving the number of rotations of the rotor that can be magnetized, it is preferable to set the target interlinkage magnetic flux vector λt so as to complete the magnetizing control at the operating point where the d-axis current value is as large as possible. On the other hand, from the viewpoint of motor efficiency, it is generally desirable to control so that the maximum torque can be obtained with the minimum current, which may be different from the target interlinkage magnetic flux vector λt described above.

In the present embodiment, after the operating point of the motor 6 reaches the point F at the time when the magnetizing control is completed, when the control main body is switched to the current FB controller 20, the current feedback PI control by the current FB controller 20 is performed. The operating point is moved from the point F to the point H by following the isotorque line. As a result, after the magnetization control is completed at the operating point where the d-axis current value is as large as possible, the target torque can be output at the operating point where the maximum torque can be obtained with the minimum current, so magnetization is possible. The efficiency of the motor 6 can be improved while increasing the number of revolutions.

As described above, according to the control device 200 of the variable magnetic force motor 6 of the second embodiment, the current feedback PI control converges the current vector to the target value in the dq coordinate system which is the rotor synchronous coordinate system of the d-axis and the q-axis. Current vector control. In the current feedback PI control, the operating point of the variable magnetic force motor 6 is the target from the operating point that outputs the target torque on the current rated circle that defines the current range that can be controlled by the variable magnetic force motor 6 when switching from the feed forward control. It outputs torque and moves it along the isotorque line to the operating point where the maximum efficiency is achieved. This makes it possible to increase the efficiency of the motor while increasing the number of revolutions that can be magnetized.

[Third Embodiment]
Hereinafter, the third embodiment will be described. The description of the same configuration as that of the first embodiment will be omitted.

FIG. 6 is a diagram schematically showing an interlinkage magnetic flux vector on αβ coordinates when the motor control device 300 of the third embodiment controls the motor 6. The difference between the control according to the present embodiment and the first embodiment is that a break point λk (intermediate interlinkage magnetic flux vector λk) is provided on the locus from the MG point to the target interlinkage magnetic flux vector λt during magnetization control. Is.

ただし、λｋは中間鎖交磁束ベクトルλｋを、λｋ－１は、中間鎖交磁束ベクトルλｋの前回値を、λｃｏｍａｎｄは、指令鎖交磁束ベクトルλｃ（３０１）を、λｔａｒｇｅｔは、目標鎖交磁束ベクトルλｔを、λｍａｇｎｅｔｉｚｅは、着減磁時の鎖交磁束ベクトルλｍａｇを、Ｖｍａｘは、ＰＷＭ電圧インバータ５の最大出力電圧を、ωは、ロータ回転速度ωを、それぞれ示している。 The intermediate interlinkage magnetic flux vector λk is determined based on the following equation (2).

However, λk is the intermediate interlinkage magnetic flux vector λk, λk-1 is the previous value of the intermediate interlinkage magnetic flux vector λk, λcommand is the command interlinkage magnetic flux vector λc (301), and λtarget is the target interlinkage magnetic flux vector. λt, λmagnetize indicates the interlinkage magnetic flux vector λmag at the time of demagnetization, Vmax indicates the maximum output voltage of the PWM voltage inverter 5, and ω indicates the rotor rotation speed ω.

In the present embodiment, the intermediate interlinkage magnetic flux vector λk is determined based on the above equation (2), and the command interlinkage magnetic flux vector λc that reaches the target interlinkage magnetic flux vector λt via the determined intermediate interlinkage magnetic flux vector λk. The motor 6 is controlled so as to realize (301). As a result, the operating point of the variable magnetic force motor 6 moves to the operating point where the target torque can be output after completing the magnetism in a shorter time, so that magnetization in a higher rotation region is possible. Moreover, the torque fluctuation during the magnetization control period can be further reduced.

Further, when the intermediate interlinkage magnetic flux vector λk is expressed on the dq plane of the interlinkage magnetic flux, it can be expressed as follows.

FIG. 7 is a diagram for explaining the intermediate interlinkage magnetic flux vector λk in the dq coordinate system. The d-axis represents the d-axis interlinkage magnetic flux λd, and the q-axis represents the q-axis interlinkage flux λq. The semicircle represented by the solid line indicates the rated interlinkage magnetic flux circle, and the inside of this circle indicates the range of the interlinkage magnetic flux that can be realized on the dq plane. Further, the line drawn from the MG point to the target interlinkage magnetic flux vector λt indicates the command interlinkage magnetic flux vector λc (103) described in the first embodiment.

With reference to the illustrated dq plane, the intermediate interlinkage flux vector λk (break point λk) is represented by the intersection with the tangent line drawn from the MG point to the rated interlinkage flux circle. By defining the intermediate interlinkage magnetic flux vector λk in this way, the magnetizable rotation speed can be further increased, and the magnetizing control can be completed even during higher speed rotation. Further, from the viewpoint of the magnetizable rotation speed, it is most preferable to set the break point λk at the above-mentioned contact, but the break point λk is the MG point in the figure, the break point λk, and the target interlinkage magnetic flux. It may be set in the region of the triangle connecting the arrival point of the vector λt. If the break point λk is set in this region, the magnetizing possible rotation speed is increased as compared with the case where the magnetizing control is completed only by the command interlinkage magnetic flux vector λc (103) in the first embodiment. Can be done.

As described above, according to the control device 300 of the variable magnetic force motor 6 of the third embodiment, the target interlinkage magnetic flux vector that outputs the target torque in the state where the permanent magnet reaches the target demagnetization amount is calculated, and the above equation (2). ) Is used to calculate the intermediate interlinkage magnetic flux vector λk, and in the feed forward control, after the demagnetization to achieve the target demagnetization amount is completed, the target interlinkage magnetic flux is passed through the intermediate interlinkage magnetic flux vector λk. The variable magnetic force motor 6 is controlled so as to realize the command interlinkage magnetic flux vector λc reaching the vector λt. This makes it possible to magnetize in a higher rotation region, minimize torque fluctuations during the feedforward control period, and further suppress vehicle vibration.

Although the embodiments of the present invention have been described above, the above embodiments are only a part of the application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiments. do not have. Further, the above-described embodiment and its modifications can be combined as appropriate.

For example, all of the permanent magnets included in the variable magnetic force motor 6 do not necessarily have to be low coercive force magnets, and may be used in combination with a high coercive force magnet.

Further, the operating state of the variable magnetic force motor 6 is not limited to the above-mentioned first operating state and the second operating state. For example, the control section for reducing the transient torque ripple that may occur during the operation of the variable magnetic force motor 6 may be defined as the third operating state. In that case, the control device of the variable magnetic force motor 6 is a load operation control by the current FB controller 20 (first operating state) and a torque ripple reduction control by the interlinkage magnetic flux FF controller 10 (third operating state). , May be configured to switch the control entity.

6 ... Variable magnetic force motor 10 ... Feedforward controller (interlinkage magnetic flux FF controller)
20 ... PI controller (current FB controller)
100, 200, 300 ... controller

Claims (7)

It is a control method of a variable magnetic force motor that changes the magnetic force of a permanent magnet during driving.
A PI control step that controls the variable magnetic force motor so as to output a target torque set based on a running request by a current feedback PI control that feeds back the current supplied to the variable magnetic force motor.
A feedforward control step of calculating a command interlinkage magnetic flux vector that outputs a torque equivalent to the target torque and controlling the variable magnetic force motor so as to realize the command interlinkage magnetic flux vector by feedforward control is included. ,
The PI control step and the feedforward control step are switched according to the operating state of the variable magnetic force motor .
The operating state includes a state in which load operation control for outputting the target torque is executed and a state in which demagnetization control for changing the magnetic force of the permanent magnet is executed.
When the demagnetization control is executed, the feedforward control step is switched to, and when the demagnetization control is completed and the load operation control is executed, the PI control step is switched to.
A target interlinkage magnetic flux vector that outputs the target torque when the permanent magnet reaches the target demagnetization amount is calculated.
The command interlinkage magnetic flux vector is calculated using the following equation (1).
In the feedforward control step, after completing the demagnetization to achieve the target demagnetization amount, the variable magnetic force motor is controlled so as to realize the command interlinkage magnetic flux vector.
A method for controlling a variable magnetic force motor.

However, in the above equation (1), λcomand is the command interlinkage magnetic flux vector, λtaget is the target interlinkage magnetic flux vector, λmagnetize is the interlinkage magnetic flux vector at the time of demagnetization, and Vmax is the maximum output of the inverter that drives the variable magnetic force motor. The voltage and ω indicate the rotor rotation speed ω of the variable magnetic force motor. Upon completion of the feedforward control step, the permanent magnet is switched to the PI control step executed based on the current command value for outputting the target torque in a state where the target demagnetization amount is reached.
The method for controlling a variable magnetic force motor according to claim 1 . The current feedback PI control is a current vector control that converges the current vector to a target value in the dq coordinate system which is a rotor synchronous coordinate system of the d-axis and the q-axis.
When switching from the feedforward control step to the PI control step, the integrated value in the current feedback PI control is reset.
The method for controlling a variable magnetic force motor according to claim 1 or 2 , wherein the variable magnetic force motor is controlled. The current feedback PI control includes non-interfering control that compensates for the velocity electromotive force generated in the d-axis and the q-axis.
The control method for a variable magnetic force motor according to claim 3 . The current feedback PI control is a current vector control that converges the current vector to a target value in the dq coordinate system which is a rotor synchronous coordinate system of the d-axis and the q-axis.
In the PI control step, when switching from the feed forward control step, the operating point of the variable magnetic force motor is an operating point that outputs the target torque on a current rated circle that defines a current range that can be controlled by the variable magnetic force motor. Therefore, the target torque is output and the target torque is moved along the isotorque line to the operating point where the maximum efficiency is achieved.
The method for controlling a variable magnetic force motor according to any one of claims 1 to 4 , wherein the variable magnetic force motor is controlled. It is a control method of a variable magnetic force motor that changes the magnetic force of a permanent magnet during driving.
A PI control step that controls the variable magnetic force motor so as to output a target torque set based on a running request by a current feedback PI control that feeds back the current supplied to the variable magnetic force motor.
A feedforward control step of calculating a command interlinkage magnetic flux vector that outputs a torque equivalent to the target torque and controlling the variable magnetic force motor so as to realize the command interlinkage magnetic flux vector by feedforward control is included. ,
The PI control step and the feedforward control step are switched according to the operating state of the variable magnetic force motor.
The operating state includes a state in which load operation control for outputting the target torque is executed and a state in which demagnetization control for changing the magnetic force of the permanent magnet is executed.
When the demagnetization control is executed, the feedforward control step is switched to, and when the demagnetization control is completed and the load operation control is executed, the PI control step is switched to.
A target interlinkage magnetic flux vector that outputs the target torque when the permanent magnet reaches the target demagnetization amount is calculated.
Calculate the intermediate interlinkage magnetic flux vector using the following equation (2),
In the feed forward control step, after completing the demagnetization to achieve the target demagnetization amount, the command interlinkage magnetic flux vector reaching the target interlinkage magnetic flux vector via the intermediate interlinkage magnetic flux vector is obtained. The variable magnetic flux motor is controlled so as to be realized.
A method for controlling a variable magnetic force motor.

However, in the above equation (2), λk is an intermediate interlinkage magnetic flux vector, λcommand is a command interlinkage magnetic flux vector, λtaget is a target interlinkage magnetic flux vector, λmagnetize is an interlinkage magnetic flux vector at the time of demagnetization, and Vmax is the variable magnetic force. The maximum output voltage of the inverter that drives the motor, ω indicates the rotor rotation speed of the variable magnetic force motor. A control device for a variable magnetic force motor equipped with a controller that controls the magnetic force of a permanent magnet during driving.
The controller
A PI controller that controls the variable magnetic force motor so as to output a target torque set based on a running request by a current feedback PI control that feeds back the current supplied to the variable magnetic force motor.
A feedforward controller that calculates a command interlinkage magnetic flux vector that outputs a torque equivalent to the target torque and controls the variable magnetic force motor so as to realize the command interlinkage magnetic flux vector by feedforward control is provided. ,
The control by the PI controller and the control by the feedforward controller are switched according to the operating state of the variable magnetic force motor .
The operating state includes a state in which load operation control for outputting the target torque is executed and a state in which demagnetization control for changing the magnetic force of the permanent magnet is executed.
When the demagnetization control is executed, the feedforward control step is switched to, and when the demagnetization control is completed and the load operation control is executed, the PI control step is switched to.
A target interlinkage magnetic flux vector that outputs the target torque when the permanent magnet reaches the target demagnetization amount is calculated.
The command interlinkage magnetic flux vector is calculated using the following equation (1).
In the feedforward control step, after completing the demagnetization to achieve the target demagnetization amount, the variable magnetic force motor is controlled so as to realize the command interlinkage magnetic flux vector.
A control device for a variable magnetic force motor.

However, in the above equation (1), λcomand is the command interlinkage magnetic flux vector, λtaget is the target interlinkage magnetic flux vector, λmagnetize is the interlinkage magnetic flux vector at the time of demagnetization, and Vmax is the maximum output of the inverter that drives the variable magnetic force motor. The voltage and ω indicate the rotor rotation speed ω of the variable magnetic force motor.

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