JP6937211B2 - Variable magnetic field 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, there is known a drive system of 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 (see Patent Document 1). This drive system has a booster circuit that boosts the DC voltage, operates this during magnetism control, and inputs the boosted voltage 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.

JP-A-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 allowance 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 aims to improve the efficiency of the entire system by suppressing the voltage required for demagnetization control and eliminating the need for an additional booster circuit, and demagnetizes and demagnetizes using a conventional inverter using PWM control. It is an object of the present invention to provide a technique capable of improving the demagnetization amount control accuracy in control and improving the motor efficiency.

The method for controlling a variable magnetic force motor according to the present invention is a method for controlling a variable magnetic force motor that changes the magnetic force of a permanent magnet during driving, estimates the current interlinkage magnetic flux vector, and demagnetizes to a target demagnetization amount. The demagnetized demagnetized interlinkage magnetic flux vector at the time of demagnetization or the interlinkage magnetic flux vector at the time of completion of control that outputs the target torque set based on the traveling request in the demagnetized state is calculated as the target interlinkage magnetic flux vector. Then, a plurality of command interlinkage magnetic flux vectors are calculated from the current interlinkage magnetic flux vector and the target interlinkage magnetic flux vector. The first step from the start of demagnetization control to the demagnetization demagnetization interlinkage magnetic flux vector and the second step from the demagnetization demagnetization interlinkage flux vector to the interlinkage flux vector when the control is completed are two or more, respectively. It is composed by combining command interlinkage magnetic flux vectors. The first stroke and the second stroke are composed of a first command interlinkage magnetic flux vector and a second command interlinkage magnetic flux vector, respectively, and the first command interlinkage magnetic flux vector and the second command interlinkage magnetic flux vector are , Determined by equation (1) described later.

According to the present invention, since the locus of the interlinkage magnetic flux vector at the time of demagnetization control can be formed by combining at least two types of command interlinkage magnetic flux vectors, the voltage utilization rate is improved and the demagnetization control is performed. The required voltage can be suppressed. Further, by combining two types of command interlinkage magnetic flux vectors, it is possible to realize a command interlinkage magnetic flux vector that matches the target interlinkage magnetic flux vector λe1 at the end of demagnetization control, so that the demagnetization amount control accuracy 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 the motor control device of the first embodiment controls a motor in demagnetization control. FIG. 3 is a diagram for explaining the output order of the command interlinkage magnetic flux vectors λc1 and λc2 in the demagnetization control of the first embodiment. FIG. 4 is a diagram for explaining the overall configuration of the demagnetization control of the first embodiment. FIG. 5 is a diagram schematically showing an interlinkage magnetic flux vector on αβ coordinates when the motor control device of the second embodiment controls the motor in demagnetization control.

[First Embodiment]
FIG. 1 is a control block diagram showing a configuration example of the control device 100 of the variable magnetic force motor 6 according to the first embodiment of the present invention.

The control device 100 of the variable magnetic force motor 6 (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 provided with a variable magnetic force motor 6.

The motor control device 100 of the present embodiment includes a vector controller 1, a current controller 2, a dq axis / UVW phase converter 3, a switch 4, a PWM voltage inverter 5, and a UVW phase / dq axis converter. 7, a magnetic flux observer 80, and an interlinkage magnetic flux controller 90 are included. Of these configurations, the magnetic flux observer 80 and the interlinkage magnetic flux controller 90 constitute a demagnetization control unit 10 that controls demagnetization of the permanent magnet included in the variable magnetic force motor 6. The control target of the motor control device 100 including the demagnetization control unit 10 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 arithmetic 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”) is a variable magnetic force motor composed of a stator having a stator winding and a rotor having a permanent magnet embedded therein. 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 through 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 force 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 alternating 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 controller 90. 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 80, and the interlinkage magnetic flux controller 90.

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 a 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 will be referred to as "load operation control".

The vector controller 1 sets the ^{d-axis current command value id *} and the q-axis current command value iq ^* , which represent 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 the d-axis current command value and the 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 refers to ^{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} are calculated and output to the current controller 2. 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 commands a magnetizing amount command to command a demagnetizing amount 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 value MS ^* is calculated and output to the interlinkage magnetic flux controller 90 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 magnet provided in the rotor in relation to the 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 controller 90. The demagnetization control for the motor 6 by the demagnetization control unit 10, which is executed in response to the magnetization 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 the magnetizing amount command value MS ^* may be obtained by calculation.

The current controller 2 is a rotor synchronous coordinate system having a d-axis whose positive direction is from the south pole to the north pole of the permanent magnet and a q-axis which is orthogonal to the d-axis and whose rotation direction of the rotor is positive. In the dq-axis coordinate system, which is, the current vector control for converging the current vector to the target value is executed. _{That is, in the current controller 2 of the present embodiment, the d-axis current detection value id} and the q-axis current detection value i _{q obtained} by converting the three-phase alternating currents iu, iv, and iw 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 is converged to the d-axis current command value i _d ^* and the q-axis current command value i _q ^{*, respectively.} 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 and the magnetic flux observer 80.

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 controller 2 as the U-phase voltage command value V, which is a three-phase voltage command value. Convert to _u ^* , V-phase voltage command value V _v ^*, and W-phase voltage command value V _w ^*.

The switch 4 includes a three-phase voltage command value Vu ^* , Vv ^* , Vw ^* (hereinafter referred to as “first three-phase voltage command value”) output from the dq-axis / UVW phase converter 3 and a chain described later. ^{The three-phase voltage command values Vu *} , Vv ^* , and Vw ^* (hereinafter referred to as "second three-phase voltage command values") output from the AC magnetic flux controller 90 during demagnetization control are used to operate the motor 6. Switch according to the state.

More specifically, the switch 4 outputs the input first-third phase voltage command value to the PWM voltage inverter 5 in the load operation control section in which the load operation is performed based on the traveling request. On the other hand, in the demagnetization / demagnetization control section in which the permanent magnet of the motor 6 is demagnetized, the output value output to the PWM voltage inverter 5 is set to the thirteenth in response to the switching command Ssw output from the interlinkage magnetic flux controller 90. Switch from the phase voltage command value to the second and third phase voltage command values.

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, three-phase alternating currents iu, iv, and iwa are supplied to the stator windings of each phase of the motor 6. The PWM voltage inverter 5 of the present embodiment uses a conventionally known general voltage type inverter. Therefore, the switching cycle of the PWM voltage inverter 5 in this embodiment is constant in principle.

The UVW phase / dq-axis converter 7 converts the three-phase alternating currents iu, iv, and iwa into d-axis real current id and q-axis real current iq based on the rotor phase θ, and feeds them back to the current controller 2. At the same time, it is output to the magnetic flux observer 80.

The magnetic flux observer 80 constitutes the demagnetization control unit 10 and calculates the current interlinkage magnetic flux vector λs. Specifically, the magnetic flux observer 80 includes the current motor currents d-axis real current id and q-axis real current iq, rotor rotation speed ω, and d-axis voltage command value V _{d output from the current controller 20.} ^The current interlinkage magnetic flux vector λs is calculated by inputting * and the q-axis voltage command value V _q ^* and the switching time Ts of the switching element included in the PWM voltage inverter 5. The switching time Ts may be acquired from a set value, or may be acquired from, for example, an actual value of a control terminal of a switching element included in the PWM voltage inverter 5. As a method for calculating the interlinkage magnetic flux vector λs executed by the magnetic flux observer 80, a conventionally known method may be used.

More specifically, for example, when the rotation speed of the motor 6 is in the low speed range, the magnetic flux observer 80 of the present embodiment includes the motor inductance (Lq, Ld) and the motor 6 in addition to the above input values. The current interlinkage magnetic flux vector λs is calculated from the magnet interlinkage magnetic flux of the permanent magnet. In a variable magnetic force motor, the motor inductance and the magnet interlinkage magnetic flux change depending on the magnetizing state (magnetization amount) of the permanent magnet, so it is necessary to ensure the accuracy of the calculated values. In the present embodiment, for example, by storing the interlinkage magnetic flux response map for the motor current in advance, the calculated interlinkage magnetic flux vector λs can be compared with the interlinkage magnetic flux response map, and the error can be grasped. Therefore, the calculation accuracy of the current interlinkage magnetic flux vector λs can be ensured by estimating the current motor inductance and the magnet interlinkage magnetic flux as values for reducing the error.

Further, for example, when the rotation speed of the motor 6 is in the medium to high speed range, the magnetic flux observer 80 _{integrates the d-axis voltage command value v d} ^* and the q-axis voltage command value v _q ^* to obtain the current chain. The cross flux vector λs can be calculated. For example, the current interlinkage magnetic flux vector λs calculated as described above is output to the interlinkage magnetic flux controller 90.

The interlinkage magnetic flux controller 90 is a feedforward controller that constitutes the magnetization demagnetization control unit 10 and is used when controlling the magnetization state (magnetization demagnetization amount) of the motor 6. The interlinkage magnetic flux controller 90 inputs the magnetizing amount command MS ^* , the rotor phase θ, the rotor rotation speed ω, the current interlinkage magnetic flux vector λs, and the torque command value T ^* (target torque). The following interlinkage magnetic flux vector is calculated. That is, the interlinkage magnetic flux controller 90 calculates a target interlinkage magnetic flux vector λe1 for achieving a desired demagnetization amount, and outputs a target torque in a state where the motor 6 achieves the demagnetization amount. The interlinkage magnetic flux vector λe2 is calculated, and the first step (pre-magnetization stroke) from the start of demagnetization control to the target interlinkage magnetic flux vector λe1 and the target after achieving the desired demagnetization amount. A plurality of command interlinkage magnetic flux vectors constituting the second stroke (post-magnetization stroke) leading to the interlinkage magnetic flux vector λe2 are calculated. In this embodiment, two types of command interlinkage magnetic flux vectors λc1 and λc2 are calculated. The details of these interlinkage magnetic flux vectors will be described below.

The calculation method of the command interlinkage magnetic flux vectors λc1 and λc2 is shown below. The process from the start of control to demagnetization (pre-magnetization process) and the process from after demagnetization to output the target torque. Since the command interlinkage magnetic flux vectors λc1 and λc2 in (post-magnetization stroke) can be calculated by the same method, the calculation method in the “pre-magnetization stroke” will be described as a typical example. Further, since the purpose of magnetizing and demagnetizing can be achieved by the same control, "magnetization control" will be described below as a typical example.

FIG. 2 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 demagnetization control. The αβ coordinates shown in FIG. 2 coincide with the center (U-axis) of the U-phase coil of the motor 6, and when they coincide with the d-axis of the rotor, the α-axis and the α-axis are positive in the direction of strengthening the magnet magnetic flux. 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. The d-axis of the rotor is close to the β-axis at the start of control, but as shown in the figure, it rotates during the magnetizing control, so it moves to a position that substantially coincides with the α-axis at the completion of the magnetizing operation.

The interlinkage magnetic flux vector 101 indicates the current interlinkage magnetic flux vector λs at the start of magnetizing control. The current interlinkage magnetic flux vector λs is calculated by the magnetic flux observer 80 as described above.

The MG point shown in the figure represents the target magnetizing amount commanded by the magnetizing amount command value MS ^*. That is, the interlinkage magnetic flux vector 102 drawn to the MG point is the interlinkage magnetic flux vector at the time of magnetization, and is the target interlinkage magnetic flux vector λe1 for achieving a desired magnetizing amount. The target interlinkage magnetic flux vector λe1 according to the magnetization amount command value MS ^* stores, for example, a map in which the target magnetic flux amount and the interlinkage magnetic flux vector that achieves the magnetization amount are associated with each other in advance. Calculated by referring to the map.

The sum of the command interlinkage magnetic flux vectors (λc1 + λc2) to be output in the pre-magnetization stroke is the interlinkage magnetic flux vector from the current interlinkage magnetic flux vector λs at the start of demagnetization control to the target interlinkage magnetic flux vector λe1. It is shown by the trajectory of. By outputting the voltage-time product that realizes this interlinkage magnetic flux vector to the target interlinkage magnetic flux vector λe1, the interlinkage magnetic flux vector λs can be moved to the target interlinkage magnetic flux vector λe1 to complete the magnetism.

Here, in order to reliably magnetize even when the motor 6 is being driven at high speed, it is preferable to complete the magnetism control in the shortest possible time. For this purpose, it is desirable to maintain the output voltage of the PWM voltage inverter 5 at the maximum during the magnetizing control period.

On the other hand, since the conventional general PWM voltage inverter 5 operates in a constant switching cycle, when the output voltage is fixed to a constant value such as the maximum output voltage, the voltage time product that can be output is discrete. Value. For this reason, in the conventional demagnetization and demagnetization control, it is difficult to match the interlinkage magnetic flux vector at the time of demagnetization and demagnetization, which is the target, with the interlinkage magnetic flux vector at the time when the control is completed, and an error occurs between the two, resulting in demagnetization. There is a problem that the magnetic flux control accuracy is lowered.

Therefore, in the present embodiment, the command interlinkage magnetic flux vector from the interlinkage magnetic flux vector λs at the start of magnetizing control to the target interlinkage magnetic flux vector λe1 is divided into the command interlinkage magnetic flux vector λc1 (103) and the command interlinkage magnetic flux vector. The above problem is solved by constructing the two types of interlinkage magnetic flux vectors of λc2 (104). The command interlinkage magnetic flux vector λc1 and the command interlinkage magnetic flux vector λc2 are determined based on the following equation (1).

However, in the above equation (1), λcomand1 is the command interlinkage magnetic flux vector λc1, λcomand2 is the command interlinkage magnetic flux vector λc2, λend is the target interlinkage magnetic flux vector λe1, λstart is the current interlinkage magnetic flux vector λs, and Vmax is the motor 6. The maximum output voltage of the PWM voltage inverter 5 for driving the PWM voltage inverter 5, T indicates the switching cycle of the PWM voltage inverter, and ω indicates the rotor rotation speed ω of the motor 6.

The command interlinkage magnetic flux vectors λc1 and λc2 calculated by the above equation (1) are as shown in FIG. The interlinkage magnetic flux vector 103 shown in the figure is a command interlinkage magnetic flux vector λc1. The command interlinkage magnetic flux vector λc1 of the present embodiment is realized by the maximum output voltage Vmax of the PWM voltage inverter 5. Then, the output voltage value that realizes the command interlinkage magnetic flux vector λc2 is determined by using the following equation (2).

However, Vcomand in the above equation (2) indicates the output voltage value of the PWM voltage inverter 5, T indicates the switching cycle of the PWM voltage inverter 5, and λcomand2 indicates the command interlinkage magnetic flux vector λc2.

When the command interlinkage magnetic flux vectors λc1 and λc2 are calculated by the above equations (1) and (2), the interlinkage magnetic flux controller 90 realizes the command interlinkage magnetic flux vectors λc1 and λc2. A switching period for calculating Vu ^* , Vv ^* , and Vw ^* and outputting them to the switch 4 and instructing the application time of the second and third phase voltage command values (switching period related to the number of switching ONs). The command value Tsw is output to the PWM voltage inverter 5. That is, the interlinkage magnetic flux controller 90 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.

As shown in FIG. 2, the locus of the command interlinkage magnetic flux vector composed of the command interlinkage magnetic flux vectors λc1 and λc2 realized as described above is the command interlinkage magnetic flux vector λc1 four times. It is realized by outputting λc2 once. In this way, by constructing the pre-magnetization process from the start of magnetization control to the target interlinkage magnetic flux vector λe1 by combining two different types of interlinkage magnetic flux vectors, the target interlinkage magnetic flux at the end of magnetization control It is possible to realize a command interlinkage magnetic flux vector that matches the vector λe1. As a result, in the magnetizing control, it is possible to accurately magnetize the permanent magnet to the target magnetizing amount.

Further, the command interlinkage magnetic flux vectors λc1 and λc2 are realized only by changing the magnitude of the voltage value (second and third phase voltage command value) and the number of outputs (switching period Tsw) while keeping the switching cycle constant. can do. Therefore, since the above-mentioned command interlinkage magnetic flux vectors λc1 and λc2 can be realized by using a conventional voltage type inverter having a constant switching cycle, the cost can be increased simply by changing the control program of the conventional voltage type inverter. It is possible to improve the demagnetization amount control accuracy and improve the motor efficiency without doing so.

Next, the order in which the command interlinkage magnetic flux vector λc1 and the command interlinkage magnetic flux vector λc2 are output will be described with reference to FIG.

FIG. 3 is a diagram schematically showing the interlinkage magnetic flux vectors on the αβ coordinates similar to FIG. 2, and is a diagram for explaining the output order of the command interlinkage magnetic flux vectors λc1 and λc2.

In this embodiment, the command interlinkage magnetic flux vector λc1 is applied from the control cycle immediately after the start of magnetizing control. Then, the command interlinkage magnetic flux vector λc2 is applied to the control cycle immediately before reaching the target interlinkage magnetic flux vector λe1. That is, the command interlinkage magnetic flux vector λc2 of the present embodiment is applied to the last control cycle in the pre-magnetization stroke.

Further, the command interlinkage magnetic flux vector λc2 output at such a timing may be determined based on the following equation (3).

However, in the above equation (3), λcomand2 is the command interlinkage magnetic flux vector λc2, λcomnd1 is the command interlinkage magnetic flux vector λc1, λend is the target interlinkage magnetic flux vector λe1, and Vmax is the maximum output of the PWM voltage inverter 5 that drives the motor 6. The voltage and T are the switching cycles of the PWM voltage inverter, and ω is the rotor rotation speed ω of the motor 6.

Then, λstart1 in the above equation (3) is the current interlinkage at the timing after the command interlinkage magnetic flux vector λc1 is output N times (4 times (see FIG. 3) in this embodiment) after the magnetization control is started. Let the magnetic flux vector λs be the estimated interlinkage magnetic flux vector. That is, the command interlinkage magnetic flux vector λc2 calculated using the above equation (3) in the present embodiment is the current interlinkage magnetic flux vector λstart1 estimated in the control cycle immediately before reaching the target interlinkage magnetic flux vector λe1. It is calculated based on. As a result, it is possible to compensate for the error that may occur while the command interlinkage magnetic flux vector λc1 is output N times after the start of the magnetizing control, so that the magnetizing amount control accuracy can be further improved.

When the current interlinkage magnetic flux vector λs represented by λstart1 is calculated by the magnetic flux observer 80, that is, when the current interlinkage magnetic flux vector λs is calculated during the magnetizing control period, the magnetic flux observer 80 is used. The input voltage command value is replaced with the d-axis voltage command value V _d ^* and the q-axis voltage command value V _q ^* output from the current controller 2, and the second and third phases output by the interlinkage magnetic flux controller 90. _{Let the voltage command values Vu *, Vu *, and Vw * be the d-axis voltage command value V d} ^* and the q-axis voltage command value V _q ^{* obtained} by converting the voltage command values Vu *, Vu *, and Vw * into dq-axis voltage command values based on the rotor phase θ.

The above is the details of the demagnetization control in the pre-magnetization process. As described above, the demagnetization control performed by the control device 100 of the variable magnetic force motor according to the present embodiment includes a pre-magnetization stroke and a post-magnetization stroke. The control of the post-magnetization process is the same as that of the pre-magnetization process. Here, FIG. 4 shows an overall mode of demagnetization control including a pre-magnetization process and a post-magnetization process.

FIG. 4 is a diagram schematically showing the interlinkage magnetic flux vector on the αβ coordinate in the entire demagnetization control composed of the pre-magnetization process and the post-magnetization process. With reference to the α-axis, the lower part of the α-axis represents the pre-magnetization stroke, and the upper part of the α-axis represents the post-magnetization stroke. The interlinkage magnetic flux vector 106 is a target interlinkage magnetic flux vector λt2 that outputs a target torque at the time of load operation control in a state where a desired demagnetization is achieved. Further, as in FIGS. 1 and 2, the interlinkage magnetic flux vector 101 is the current interlinkage magnetic flux vector λs at the start of demagnetization control, and the interlinkage magnetic flux vector 102 is the interlinkage magnetic flux vector at the time of demagnetization. A certain target interlinkage magnetic flux vector λt1, the alternate long and short dash line represents the d-axis of the motor 6.

As shown in the figure, the sum of the command interlinkage magnetic flux vectors in the pre-magnetization stroke (λc1, λc2) and the sum of the command interlinkage magnetic flux vectors in the post-magnetization stroke (λc1, λc2) are composed of the same combination. ..

However, the control start time point in the post-magnetization stroke is the target interlinkage magnetic flux vector λt2, which is the interlinkage magnetic flux vector at the time of demagnetization, and this is the current interlinkage magnetic flux vector at the start of control in the pre-magnetization stroke. Corresponds to λs. Further, the control completion point in the post-magnetization stroke is the target interlinkage magnetic flux vector λt2 that outputs the target torque, which corresponds to the target interlinkage magnetic flux vector λt1 in the pre-magnetization stroke. Therefore, when the command interlinkage magnetic flux vectors λc1 and λc2 in the post-magnetization stroke are calculated, the λstart representing the current interlinkage magnetic flux vectors λs in the above equations (1) to (3) is the chain at the time of demagnetization. The value matches the target interlinkage magnetic flux vector λt1, which is the cross-flux vector. Further, for λend, a target interlinkage magnetic flux vector λt2 capable of outputting a target torque is set. As a result, the loci of the command interlinkage magnetic flux vectors λc1 and λc2 similar to those in the pre-magnetization process can be realized in the post-magnetization process by the same control as in the pre-magnetization demagnetization process. As described above, the current interlinkage magnetic flux vector λs during magnetization control is based on the rotor phase θ based on the second and third phase voltage command values Vu *, Vu *, and Vw * output by the interlinkage magnetic flux controller 90. It is calculated based on _{the d-axis voltage command value V d} ^* and the q-axis voltage command value V _q ^* converted into the dq-axis voltage command value.

With the above configuration, the demagnetization control can be completed by combining at least two types of command interlinkage magnetic flux vectors, so that the number of command chains is significantly smaller than that of the commonly used FB control. The demagnetization control can be completed by combining the cross flux vectors. Further, as described above, the demagnetization control of the present embodiment can be performed by using a voltage type inverter using the conventional PWM control. Therefore, the demagnetization control can be performed with a high voltage utilization rate without increasing the cost, so that the demagnetization amount control accuracy can be improved without lowering the number of rotations of the motor that can be magnetized. Therefore, the motor efficiency can be improved.

As described above, the motor control device 100 of the present embodiment executes the magnetizing control by the interlinkage magnetic flux controller 90 separately from the load operation during the magnetizing control. Therefore, the motor control device 100 of the present embodiment does not need to perform magnetization control by the interlinkage magnetic flux controller 90 in synchronization with the rotation (phase) of the rotor. Therefore, 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 magnetizing control is performed at the same time, and the voltage required for the magnetizing 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.

As described above, the variable magnetic force motor control device 100 of the first embodiment is a motor control device 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 estimates the current interlinkage magnetic flux vector λs, and determines the demagnetization demagnetization demagnetization flux vector (target interlinkage flux vector λe1) when demagnetizing to the target demagnetization amount, or the traveling request. The interlinkage magnetic flux vector (target interlinkage magnetic flux vector λe2) at the time of completion of control that outputs the target torque set based on the demagnetization is calculated as the target interlinkage magnetic flux vector, and the current interlinkage magnetic flux vector. A plurality of command interlinkage magnetic flux vectors λc1 and λc2 are calculated from λs and the target interlinkage magnetic flux vector. Then, the first step from the start of demagnetization control to the demagnetization demagnetization interlinkage flux vector (pre-magnetization process) and the second step from the demagnetization demagnetization interlinkage flux vector to the interlinkage flux vector when the control is completed. (Post-arrival stroke) is configured by combining two or more command interlinkage magnetic flux vectors. As a result, a command interlinkage magnetic flux vector that matches the target interlinkage magnetic flux vector λe1 at the end of the magnetization control can be realized, so that the demagnetization amount control accuracy can be improved.

Further, according to the control device 100 of the variable magnetic force motor of the first embodiment, the first command interlinkage magnetic flux vector (λc1) and the second command interlinkage magnetic flux vector (λc2) are the pre-magnetization stroke and the post-magnetization stroke, respectively. ) And. As a result, the locus of the interlinkage magnetic flux vector during demagnetization control can be constructed by combining at least two types of command interlinkage magnetic flux vectors, so that the voltage utilization rate is improved and the voltage required for demagnetization control can be reduced. It can be suppressed.

Further, according to the control device 100 of the variable magnetic force motor of the first embodiment, the command interlinkage magnetic flux vector λc1 and the command interlinkage magnetic flux vector λc2 are determined by the above equation (1). As a result, the command interlinkage magnetic flux vector can be calculated from the current interlinkage magnetic flux vector and the target interlinkage magnetic flux vector by the agile configuration by programming the calculation formula with the controller. The magnetic flux control accuracy can be improved and the motor efficiency can be improved.

Further, according to the control device 100 of the variable magnetic flux motor of the first embodiment, the command interlinkage magnetic flux vector λc2 is the current interlinkage magnetic flux vector estimated in at least one control cycle before reaching the target interlinkage magnetic flux vector. It is calculated from λc1 and applied to the control cycle immediately before reaching the target interlinkage flux vector. As a result, the command interlinkage magnetic flux vector can be reached to the target interlinkage magnetic flux vector without extending the magnetization control time and without lowering the magnetizable rotation speed, so that the magnetism amount control accuracy is improved. The motor efficiency can be further improved.

Further, according to the control device 100 of the variable magnetic force motor of the first embodiment, the command interlinkage magnetic flux vector λc2 is the magnitude of the voltage applied to the variable magnetic field motor (second three-phase voltage command value) or the said voltage. It is realized by changing the application time (switching period). Further, the command interlinkage magnetic flux vector λc2 is realized by the inverter driving the variable magnetic field motor outputting the voltage calculated by the above equation (2) during the switching cycle. As a result, the above demagnetization control can be realized only by changing the voltage command value while the switching cycle is fixed. Therefore, the demagnetization amount control accuracy can be improved and the motor efficiency can be improved without increasing the cost. Can be done.

Further, according to the control device 100 of the variable magnetic flux motor of the first embodiment, the current interlinkage magnetic flux vector λs is the current motor current (d-axis real current id and q-axis real current iq) supplied to the variable magnetic flux motor. ), The voltage command value to the variable magnetic flux motor (d-axis voltage command value V _d ^* and q-axis voltage command value V _q ^* ), and the motor rotation speed (rotor rotation speed ω). The cross-flux vector (λe1) is calculated from the rotor rotation speed ω and the demagnetization amount command MS ^*, and the interlinkage flux vector (λe2) at the completion of control is calculated from the target torque (torque command value T ^* ). The command interlinkage magnetic flux vectors λc1 and λc2 are the demagnetized demagnetization interlinkage magnetic flux vector (λe1) or the interlinkage magnetic flux vector (λe2) when the control is completed, the current interlinkage magnetic flux vector λs, and the rotor of the variable magnetic force motor. It is calculated from the phase θ and the rotor rotation speed ω. The calculated command interlinkage magnetic flux vectors λc1 and λc2 are realized by controlling the output voltage output by the inverter driving the variable magnetic force motor and the output time (switching period) of the output voltage. As a result, the above-mentioned demagnetization control can be realized by using a conventional general voltage type inverter. Therefore, only by changing the control program of the conventional voltage type inverter, the amount of demagnetization can be reduced without increasing the cost. The magnetic quantity control accuracy can be improved and the motor efficiency can be improved.

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

The difference between this embodiment and the first embodiment is the output order of the command interlinkage magnetic flux vectors λc1 and λc2.

In the present embodiment, the command interlinkage magnetic flux vector λc2 is applied to the control cycle immediately after the start of demagnetization control or the control cycle immediately after the start of demagnetization control. That is, the command interlinkage magnetic flux vector λc2 of the present embodiment is applied to the first (first) or second control cycle in the pre-magnetization stroke. Then, the command interlinkage magnetic flux vector λc1 is applied to the second and subsequent times when the command interlinkage magnetic flux vector λc2 is applied to the first control cycle, and the command interlinkage magnetic flux vector λc2 is applied to the second control cycle. If so, it is applied to the first and third control cycles.

FIG. 5 is a diagram schematically showing the interlinkage magnetic flux vector on the αβ coordinates when the motor control device 200 of the second embodiment performs demagnetization control of the motor 6, and the command interlinkage magnetic flux vector λc2 is , Is a diagram showing a case where it is applied to a control cycle immediately after the start of magnetizing control.

The illustrated command interlinkage magnetic flux vectors λc1 (201) and λc2 (202) are λcomand1 and λcommand2 of the formula (1) used in the first embodiment. As shown in the figure, the command interlinkage magnetic flux vector λc2 of the present embodiment is output starting from the current interlinkage magnetic flux vector λs immediately after the start of magnetizing control.

Here, in order to perform demagnetization faster, it is preferable that the command interlinkage magnetic flux vector λc1 is realized at the maximum output voltage. Therefore, the motor current becomes large after the start of magnetizing control, and the output period of the command interlinkage magnetic flux vector λc1 becomes maximum. Therefore, the command interlinkage magnetic flux vector λc2, which can be realized with an output voltage smaller than the command interlinkage magnetic flux vector λc1, is obtained immediately after the start of magnetizing control or during the period when the motor current is still low (before reaching the maximum value) in the second control cycle. Apply to. As a result, it is possible to avoid the situation where the motor current is reduced in order to realize the command interlinkage magnetic flux vector λc2 after the motor current reaches the maximum value, so that the efficiency in the entire demagnetization control period can be improved.

As described above, according to the control device 200 of the variable magnetic force motor of the second embodiment, the command interlinkage magnetic flux vector λc2 has a control cycle immediately after the start of the pre-magnetization stroke, a control cycle next to the control cycle, and a post-magnetization. It is applied to the control cycle immediately after the start of control or the control cycle next to the control cycle. As a result, the command interlinkage magnetic flux vector λc2 can be calculated during the period when the motor current is still low, so that the efficiency in the entire demagnetization control period can be improved.

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

The motor control device 300 of the present embodiment is different from the first embodiment in the method of realizing the command interlinkage magnetic flux vector λc2. In order to realize the command interlinkage magnetic flux vector λc2 described below, the PWM voltage inverter 5 included in the motor control device 300 of the present embodiment is a switching cycle variable type inverter capable of controlling its switching cycle (switching ON time). It is assumed that there is.

The command interlinkage magnetic flux vector λc2 of the present embodiment is realized by outputting the maximum output voltage of the PWM voltage inverter 5 to the motor 6 during the time Tcomand determined by the following equation (4).

However, in the above equation (4), Tcomand indicates the power output time, λcomand2 indicates the command interlinkage magnetic flux vector λc2, and Vmax indicates the maximum output voltage of the PWM voltage inverter 5.

The interlinkage magnetic flux vector can be realized by the voltage-time product consisting of the voltage applied to the motor 6 and the phase component (switching period). Therefore, the command interlinkage magnetic flux vector λc2 of the present embodiment achieves substantially the same voltage-time product as that of the first embodiment in a shorter time by maximizing the applied voltage and adjusting the switching cycle accordingly. can do. Therefore, since the time required for magnetizing control can be shortened, it is possible to improve the magnetizing demagnetization amount control accuracy and improve the motor efficiency while increasing the rotor rotation speed capable of magnetizing and demagnetizing control. can.

As described above, according to the control device 300 of the variable magnetic force motor of the third embodiment, the command interlinkage magnetic flux vector outputs the maximum output voltage of the inverter during the voltage output time calculated by the above equation (4). It will be realized. As a result, the maximum voltage output can be maintained during the landing control period, so that the time required for the landing demagnetization control can be shortened. As a result, it is possible to improve the precision of controlling the amount of demagnetization and the motor efficiency while improving the number of rotations capable of controlling demagnetization.

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 configurations of the above embodiments. No. In addition, the above embodiments 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 magnets, and may be used in combination with high coercive magnets.

Further, the demagnetization control unit 10 does not necessarily have to be applied to the motor control device 100 shown in FIG. 1 or the motor control device 300 including the PWM voltage inverter 5 having a variable switching cycle. The demagnetization control unit 10 can be applied as a functional unit that controls demagnetization of the variable magnetic force motor if the system targets the variable magnetic force motor.

5 ... Inverter (PWM voltage inverter)
6 ... Variable magnetic field motor 10, 100, 200, 300 ... Controller

Claims (9)

It is a control method of a variable magnetic force motor that executes demagnetization control that changes the magnetic force of a permanent magnet while driving the motor.
Estimate the current interlinkage flux vector
Demagnetization / demagnetization when demagnetizing to the target demagnetization amount Demagnetization / demagnetization The magnetic flux vector or the target torque set based on the traveling request is output in the demagnetized state. Calculate the magnetic flux vector as the target interlinkage magnetic flux vector,
A plurality of command interlinkage magnetic flux vectors are calculated from the current interlinkage magnetic flux vector and the target interlinkage magnetic flux vector.
The first step from the start of the demagnetization control to the demagnetization demagnetization interlinkage magnetic flux vector, and from the demagnetization demagnetization interlinkage flux vector to the interlinkage flux vector at the completion of the control. The second stroke is configured by combining two or more of the command interlinkage magnetic flux vectors .
The first stroke and the second stroke are composed of a first command interlinkage magnetic flux vector and a second command interlinkage magnetic flux vector, respectively.
The first command interlinkage magnetic flux vector and the second command interlinkage magnetic flux vector are determined by the following equation (1).
A method for controlling a variable magnetic force motor, which is characterized in that.

However, in the above equation (1), λcomand1 is the first command interlinkage magnetic flux vector, λcomand2 is the second command interlinkage magnetic flux vector, λend is the target interlinkage magnetic flux vector, and λstart is the current interlinkage magnetic flux vector. Vmax is the maximum output voltage of the inverter that drives the variable magnetic flux motor, T is the switching cycle of the inverter, ω is the rotor rotation speed of the variable magnetic flux motor, and n is an integer. The second command interlinkage magnetic flux vector is calculated from the current interlinkage magnetic flux vector estimated in at least one control cycle before reaching the target interlinkage magnetic flux vector, and immediately before reaching the target interlinkage magnetic flux vector. Applicable in the control cycle,
The method for controlling a variable magnetic force motor according to claim 1 , wherein the variable magnetic force motor is controlled. The second command interlinkage magnetic flux vector is used in the control cycle immediately after the start of the first stroke or the control cycle next to the control cycle, and in the control cycle immediately after the start of the second stroke or the control cycle next to the control cycle. Applies,
The method for controlling a variable magnetic force motor according to claim 1 , wherein the variable magnetic force motor is controlled. The second command interlinkage magnetic flux vector is realized by changing the magnitude of the voltage applied to the variable magnetic force motor or the application time of the voltage.
The method for controlling a variable magnetic force motor according to any one of claims 1 to 3, wherein the variable magnetic force motor is controlled. The second command interlinkage magnetic flux vector is realized by the inverter driving the variable magnetic force motor outputting the voltage calculated by the following equation (2) during the switching cycle.
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.

However, in the above equation (2), Vcomand indicates the voltage output by the inverter, T indicates the switching cycle of the inverter, and λcomand2 indicates the second command interlinkage magnetic flux vector. The second command interlinkage magnetic flux vector is realized by outputting the maximum output voltage of the inverter during the voltage output time calculated by the following equation (3).
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.

However, in the above equation (3), Tcomand indicates the voltage output time, Vmax indicates the maximum output voltage of the inverter, and λcomand2 indicates the second command interlinkage magnetic flux vector. It is a control method of a variable magnetic force motor that executes demagnetization control that changes the magnetic force of a permanent magnet while driving the motor.
Estimate the current interlinkage flux vector
Demagnetization / demagnetization when demagnetizing to the target demagnetization amount Demagnetization / demagnetization The magnetic flux vector or the target torque set based on the traveling request is output in the demagnetized state. Calculate the magnetic flux vector as the target interlinkage magnetic flux vector,
A plurality of command interlinkage magnetic flux vectors are calculated from the current interlinkage magnetic flux vector and the target interlinkage magnetic flux vector.
The first step from the start of the demagnetization control to the demagnetization demagnetization interlinkage magnetic flux vector, and from the demagnetization demagnetization interlinkage flux vector to the interlinkage flux vector at the completion of the control. The second stroke is configured by combining two or more of the command interlinkage magnetic flux vectors.
The current interlinkage magnetic flux vector is calculated from the current motor current supplied to the variable magnetic force motor, the voltage command value to the variable magnetic force motor, and the motor rotation speed.
The demagnetizing demagnetization interlinkage magnetic flux vector is calculated from the motor rotation speed and the target demagnetizing amount.
The interlinkage magnetic flux vector at the completion of the control is calculated from the target torque.
The command interlinkage magnetic flux vector includes the demagnetized demagnetization interlinkage magnetic flux vector or the interlinkage magnetic flux vector at the time of completion of the control, the current interlinkage magnetic flux vector, the rotor phase of the variable magnetic force motor, and the motor rotation speed. Calculated from
The calculated command interlinkage magnetic flux vector is realized by controlling the output voltage output by the inverter driving the variable magnetic force motor and the output time of the output voltage.
Control method for variable force motor you wherein a. 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
Estimate the current interlinkage flux vector
The interlinkage magnetic flux vector at the time of demagnetization or the interlinkage magnetic flux vector that outputs the target torque set based on the traveling request is calculated as the target interlinkage magnetic flux vector.
A plurality of command interlinkage magnetic flux vectors are calculated from the current interlinkage magnetic flux vector and the target interlinkage magnetic flux vector.
The first process from the start of demagnetization control to the interlinkage magnetic flux vector at the time of demagnetization, and the second process from the interlinkage magnetic flux vector at the time of demagnetization to the interlinkage magnetic flux vector that outputs the target torque. Is constructed by combining two or more of the command interlinkage magnetic flux vectors.
The first stroke and the second stroke are composed of a first command interlinkage magnetic flux vector and a second command interlinkage magnetic flux vector, respectively.
The first command interlinkage magnetic flux vector and the second command interlinkage magnetic flux vector are determined by the following equation (1).
A control device for a variable magnetic force motor.

However, in the above equation (1), λcomand1 is the first command interlinkage magnetic flux vector, λcomand2 is the second command interlinkage magnetic flux vector, λend is the target interlinkage magnetic flux vector, and λstart is the current interlinkage magnetic flux vector. Vmax is the maximum output voltage of the inverter that drives the variable magnetic flux motor, T is the switching cycle of the inverter, ω is the rotor rotation speed of the variable magnetic flux motor, and n is an integer. 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
Estimate the current interlinkage flux vector
The interlinkage magnetic flux vector at the time of demagnetization or the interlinkage magnetic flux vector that outputs the target torque set based on the traveling request is calculated as the target interlinkage magnetic flux vector.
A plurality of command interlinkage magnetic flux vectors are calculated from the current interlinkage magnetic flux vector and the target interlinkage magnetic flux vector.
The first process from the start of demagnetization control to the interlinkage magnetic flux vector at the time of demagnetization, and the second process from the interlinkage magnetic flux vector at the time of demagnetization to the interlinkage magnetic flux vector that outputs the target torque. Is constructed by combining two or more of the command interlinkage magnetic flux vectors.
The current interlinkage magnetic flux vector is calculated from the current motor current supplied to the variable magnetic force motor, the voltage command value to the variable magnetic force motor, and the motor rotation speed.
The demagnetized demagnetization interlinkage magnetic flux vector is calculated from the motor rotation speed and the target demagnetized demagnetization amount.
The interlinkage magnetic flux vector at the completion of the control is calculated from the target torque.
The command interlinkage magnetic flux vector includes the demagnetized demagnetization interlinkage magnetic flux vector or the interlinkage magnetic flux vector at the time of completion of the control, the current interlinkage magnetic flux vector, the rotor phase of the variable magnetic force motor, and the motor rotation speed. Calculated from and
The calculated command interlinkage magnetic flux vector is realized by controlling the output voltage output by the inverter driving the variable magnetic force motor and the output time of the output voltage.
A control device for a variable magnetic force motor.

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