JP2021129438A - Motor control device - Google Patents

Abstract

To provide a motor control device that can avoid high battery voltage and increase in motor size.SOLUTION: Provided are a motor 3 and a control unit 21, the motor 3 having a stator 34 on which a plurality of coils 36 are installed facing magnets 35 of a rotor 33 with a gap therebetween, and the control unit 21 having a magnetizing current control unit 21b that changes the magnetic force generated in the coils 36. When the rotor 33 rotates, and a predetermined coil 36 passes from one end Epf to the other end Epr in the circumferential direction of a predetermined magnetic pole 35a, the magnetic force change control to change the magnetic force of the magnets 35 by controlling the magnetizing current is executed.SELECTED DRAWING: Figure 7

Description

The technology to be disclosed relates to a motor control device.

In recent years, the use of motors in electric vehicles and hybrid vehicles is increasing. For example, Patent Document 1 discloses a hybrid vehicle equipped with such a drive motor (also used as a generator) and an engine. The hybrid vehicle is equipped with a high-power battery having a rated voltage of several hundred volts that can be charged by connecting to a charging station or a household power source as a power source for the drive motor.

Regarding the technique to be disclosed, Patent Document 2 discloses a motor for a washing machine, which can increase and demagnetize the magnetic force of a magnet.

In a washing machine, a high torque and low rotation motor output is required in the washing and rinsing process, and a low torque and high rotation motor output is required in the dehydration process. Therefore, the washing machine is provided with a transmission, and the output of the motor can be switched in two stages according to both of these steps. In the washing machine of Patent Document 2, the output characteristics of the motor are changed according to the load by increasing or demagnetizing the magnetic force of the magnet from the normal magnetic force for each motor output switched by the transmission. I am trying to optimize it.

Japanese Unexamined Patent Publication No. 2014-231290 Japanese Unexamined Patent Publication No. 2011-200545

As mentioned above, in a washing machine, the high frequency output required of a motor is limited to two output ranges. Therefore, it is possible to optimize the motor output by simply switching to either one with the transmission and energizing or demagnetizing the magnet according to the magnitude of the load based on the normal magnetic force in each output range. ..

However, a drive motor mounted on an automobile or the like is required to have an extremely high output capable of driving in a very wide range in both the load direction and the rotation direction. Moreover, since it moves by itself, there is no choice but to use a battery as its power source.

Under such restrictions, in order to realize a high-output drive motor, it is conceivable to mount a high-voltage battery as in the hybrid vehicle of Patent Document 1 or to mount a large motor. However, in either case, the equipment becomes larger and heavier.

The main purpose of the technology disclosed therein is to provide a motor control device that can avoid increasing the voltage of the battery and increasing the size of the motor.

The technology to be disclosed relates to a motor control device.

In the motor control device, magnets are installed so that a plurality of magnetic poles are arranged in the circumferential direction, and a rotor for outputting rotational power and a plurality of coils facing the magnet with a gap are arranged in the circumferential direction. A motor having a stator installed in the coil and a control device having a magnetization current control unit that controls a magnetization current flowing through the coil to change the magnetic force generated in the coil.

The control device receives the magnetization current when the rotor is rotating so that a predetermined coil in the plurality of coils passes from one end to the other end in the circumferential direction of the predetermined magnetic poles in the plurality of magnetic poles. The control unit is configured to execute magnetic force change control that changes the magnetic force of the magnet by controlling the magnetization current.

That is, according to this motor control device, the control device has a magnetization current control unit that controls the magnetization current flowing through the coil and changes the magnetic force generated in the coil. Then, the magnetization current control unit changes the magnetic force of the magnet by controlling the magnetization current. That is, the magnetic force of the rotor magnet can be changed to a large or small size.

As a result, the magnetic force of the magnetic poles can be changed according to the load of the motor, so that the power factor of the motor can be increased. If the power factor of the motor is increased, a high output can be obtained with a small amount of electric power, so that the motor can be made lightweight and compact, and an appropriate output can be exhibited in a wide range. Therefore, it is possible to avoid increasing the voltage of the battery and increasing the size of the motor.

However, in order to change the magnetic force of the magnet, it is necessary to make the magnetic pole that changes the magnetic force and a predetermined coil face each other and generate a strong magnetic field in the coil. At that time, if the magnetic field applied to the magnetic poles is biased, the magnetization distribution of the magnetic poles may become non-uniform.

That is, since the positional relationship between the magnetic pole and the coil changes every moment as the rotor rotates, the magnetic field distribution formed when a strong magnetic field is generated in the coil also changes every moment. Therefore, the timing of magnetization that generates a strong magnetic field in the coil deviates from the optimum timing at which the bias of the magnetic field becomes small, and the magnetic distribution of the magnetic poles tends to be non-uniform. As a result, the motor cannot properly output the rotational power, and the motor output decreases.

Therefore, in this motor control device, when the rotor is rotating and a predetermined coil passes from one end to the other end in the circumferential direction of a predetermined magnetic pole, the magnetic force of the magnet is controlled by controlling the magnetization current flowing through the coil. The magnetic force change control to be changed is executed.

According to this motor control device, since the rotor is rotating, the magnetic poles installed in the rotor so as to be aligned in the circumferential direction are also rotated accordingly. Then, when the predetermined coil (control target coil) passes from one end to the other end in the circumferential direction of the predetermined magnetic pole, that is, the magnetic pole subject to magnetic force change control (control target magnetic pole), the magnetization current flowing through the control target coil By controlling the above, the magnetic force of the magnetic pole to be controlled is changed.

That is, while the control target magnetic pole passes through the control target coil, a strong magnetic force that magnetizes the control target magnetic pole is applied to the control target magnetic pole from the control target coil. Then, even if the magnetic field changes due to the rotation of the coil to be controlled, the magnetic field is applied to the magnetic pole to be controlled while constantly moving. As a result, it is possible to suppress the action of the magnetic field biased to a specific portion, and it is possible to suppress the non-uniformity of the magnetization distribution of the magnetic pole to be controlled.

Therefore, according to this motor control device, the motor can stably output an appropriate rotational power, so that the motor output can be sufficiently increased.

The motor control device may also be mounted on an automobile, and the magnetic force change control may be executed while the automobile is moving.

When the car is moving, the motor always sways greatly and its posture changes constantly. Therefore, if the magnetic force is changed in that state, the magnetic field is greatly disturbed, and the magnetization distribution of the magnetic poles tends to become more non-uniform. On the other hand, according to this motor control device, magnetic field change control is performed while the rotor is rotating. Therefore, as described above, even if there is shaking or unstable posture, the magnetic field is biased to a specific part. The action can be suppressed and the effect can be effectively mitigated. Therefore, it is possible to suppress the non-uniformity of the magnetization distribution of the magnetic pole to be controlled.

Moreover, since the rotor is rotating, it is possible to output rotational power from the motor even while the magnetic force change control is being executed. Therefore, the magnetic force change control can be performed while outputting the rotational power for moving the automobile by the motor, so that the movement of the automobile is not significantly hindered.

Further, as described above, in order to change the magnetic force of the magnet, it is necessary to generate a strong magnetic field in the coil, and for that purpose, it is necessary to pass a large magnetization current through the coil. In particular, in this motor control device, the magnetic force is changed while the magnetic pole is rotating, so that the magnetization efficiency is not high. Therefore, there is a problem that power consumption is severe when the magnetic force change control is performed.

On the other hand, when the car is moving, it is possible to generate electricity by regeneration. Therefore, even if the electric power is reduced by the magnetic force change control, the electric power of the power source can be easily restored by charging.

The motor control device also executes the magnetic force change control when the rotation of the rotor is less than a predetermined rotation speed set in the control device, and executes the magnetic force change control when the rotation speed is equal to or higher than the predetermined rotation speed. You may not.

As the rotation speed of the rotor increases, the magnetization time becomes shorter, so that the required magnetic force may not be changed by one magnetization. In addition, the magnetization distribution of the magnetic poles tends to be non-uniform. On the other hand, as the rotation speed of the rotor decreases, the magnetization time becomes longer, so that the amount of magnetic force that can be changed by one magnetic force change control increases, and the magnetization distribution of the magnetic poles tends to be uniform. Therefore, the accuracy of magnetic force change control is improved.

On the other hand, according to this motor control device, the magnetic force change control is executed at a low rotation speed of less than a predetermined rotation speed, and the magnetic force change control is not executed at a high rotation speed of a predetermined rotation speed or more, so that the accuracy of the magnetic force change control is improved. improves. Further, at high rotation, the magnetization efficiency decreases, so that an unnecessary magnetization current increases. By not executing the magnetic force change control at high rotation speed, it is possible to suppress the application of unnecessary magnetization current.

In the motor control device, the plurality of coils are composed of a plurality of coil groups having different phases of flowing currents, and the control device executes the magnetic force change control using the plurality of the coil groups. Therefore, the magnetic forces of all the magnetic poles may be changed at once.

That is, according to this motor control device, since a plurality of coils are composed of a plurality of coil groups having different phases of flowing currents, by passing a magnetization current through the coils of any of the coil groups, a plurality of coils can be simultaneously flown. The magnetic force can be changed with the coil. Therefore, the number of times the magnetic force change control is executed can be reduced.

Further, in this motor control device, the magnetic force is changed while the rotor is rotating. Therefore, while the magnetic force of one of the magnetic poles is being changed by any of the coil groups, the other magnetic poles may start to pass through the other coil group. Therefore, by executing the magnetic force change control using a plurality of coil groups, it is possible to change the magnetic force of a plurality of magnetic poles in parallel at the same time. Then, if the magnetic forces of all the magnetic poles are changed at once, the magnetic forces of all the magnetic poles can be changed in a short time.

The motor control device may also change the magnetic force of the magnetic pole by executing the magnetic force change control a plurality of times with respect to the same magnetic pole.

As described above, the higher the rotation speed of the rotor, the shorter the magnetization time. Therefore, there is a possibility that the required magnetic force cannot be changed by one magnetization. In addition, the magnetization distribution of the magnetic poles tends to be non-uniform. On the other hand, according to this motor control device, the magnetic force of the magnetic pole is changed by executing the magnetic force change control a plurality of times with respect to the same magnetic pole. By doing so, even if the rotation speed of the rotor becomes high or fluctuates, the magnetic pole can be changed to the required magnetic force.

Further, the magnetization distribution tends to be non-uniform due to the influence of harmonics caused by the rotation of the rotor, but if the magnetization is performed multiple times, the influence is also reduced, so that the uniformity of the magnetization distribution of the magnetic poles is further improved. Can be improved.

The motor control device may also be such that the control device drives the motor and executes the magnetic force change control while outputting the rotational power to the wheels of the automobile.

That is, this motor control device can drive the motor and output the rotational power to the wheels to drive the automobile. Since this motor control device executes magnetic force change control while outputting rotational power to the wheels, it is possible to change the magnetic force of the magnet while traveling without significantly hindering the traveling of the automobile.

Normally, when a car is driving, it is more often when it is running than when it is stopped. Therefore, if the magnetic force of the magnet can be changed while driving, the motor can be effectively used. Therefore, the performance of the automobile can be improved.

The motor control device also comprises a battery that constitutes a power source for the motor and energizes the coil with the magnetization current, and executes the magnetic force change control when the voltage of the battery is less than a predetermined lower limit value. May be restricted.

That is, in this motor control device, a battery is used as a power source for the motor, and the magnetization current used for changing the magnetic force is also energized from the battery. As described above, in order to change the magnetic force of the magnet, it is necessary to pass a large magnetization current through the coil. Therefore, if the magnetic force change control is performed, the battery may be rapidly consumed and a voltage abnormality may occur.

On the other hand, according to this motor control device, when the voltage of the battery is less than a predetermined lower limit value, the execution of the magnetic force change control is restricted, so that the occurrence of voltage abnormality can be suppressed.

The motor control device is also configured such that the vehicle includes an engine and the motor and the engine cooperate to drive the vehicle based on the operation of the accelerator, and the rated voltage of the battery is 50 V. It may be as follows.

That is, this motor control device is mounted on an automobile driven by an engine and a motor. Since a so-called low-voltage battery is used as the battery, it is possible to avoid increasing the voltage of the battery. Furthermore, as described above, a motor control device that can sufficiently increase the motor output is installed, and since these are effectively combined, it is possible to avoid increasing the size and weight of the equipment including the motor. can.

According to the disclosed technology, it is possible to realize a motor control device that can avoid increasing the voltage of the battery and increasing the size of the motor.

It is the schematic which shows the main composition of the automobile to which the disclosed technology is applied. It is a schematic cross-sectional view which shows the structure of a motor. It is a block diagram which shows the MCU and the main input / output device related thereto. It is a figure which shows the structure of the motor control device in a simplified manner. It is a flowchart which shows an example of the control of a motor performed by MCU. It is a figure for demonstrating static magnetic force change control. It is a figure for demonstrating dynamic magnetic force change control. It is a figure for demonstrating dynamic magnetic force change control. It is a flowchart which shows an example of the main processing of a magnetic force change control. It is a flowchart which shows an example of the alignment control. It is a flowchart which shows an example of static magnetic force change control. It is a flowchart which shows an example of dynamic magnetic force change control. It is a flowchart which shows an example of the magnetization execution limit control.

Hereinafter, embodiments of the disclosed technology will be described in detail with reference to the drawings. However, the following description is essentially merely an example and does not limit the present invention, its application or its use.

<Car>
FIG. 1 shows a four-wheeled vehicle 1 to which the disclosed technology is applied. This automobile 1 is a hybrid vehicle. The engine 2 and the motor 3 are mounted on the drive source of the automobile 1. These work together to rotationally drive two of the four wheels 4F, 4F, 4R, and 4R (driving wheels 4R) that are symmetrically located. As a result, the automobile 1 moves (runs).

In the case of the automobile 1, the engine 2 is arranged on the front side of the vehicle body, and the drive wheels 4R are arranged on the rear side of the vehicle body. That is, this automobile 1 is a so-called FR vehicle. Further, in the case of the automobile 1, the engine 2 is mainly used as the drive source rather than the motor 3, and the motor 3 is used in a form of assisting the drive of the engine 2 (so-called mild hybrid). The motor 3 is also used not only as a drive source but also as a generator during regeneration.

In addition to the engine 2 and the motor 3, the automobile 1 is provided with a first clutch 5, an inverter 6, a second clutch 7, a transmission 8, a differential gear 9, a battery 10, and the like as drive system devices. The automobile 1 runs by the action of the complex (drive system) of these devices.

The automobile 1 also has an engine control unit (ECU) 20, a motor control unit (MCU) 21, a transmission control unit (TCU) 22, a brake control unit (BCU) 23, and a comprehensive control unit (GCU) as control system devices. ) 24 and the like are provided.

The engine rotation sensor 50, the motor rotation sensor 51, the current sensor 52, the magnetic force sensor 53, the accelerator sensor 54, and the like are also installed in the automobile 1 along with the control system device.

[Drive system device]
The engine 2 is, for example, an internal combustion engine that burns using gasoline as fuel. The engine 2 is also a so-called four-cycle engine that generates rotational power by repeating each cycle of intake, compression, expansion, and exhaust. The engine 2 has various types and forms such as a diesel engine, but the disclosed technology does not particularly limit the type and form of the engine.

In the automobile 1, the engine 2 is arranged at a substantially central portion in the vehicle width direction with the output shaft for outputting the rotational power directed in the front-rear direction of the vehicle body. Various devices and mechanisms associated with the engine 2, such as an intake system, an exhaust system, and a fuel supply system, are installed in the automobile 1, but the illustration and description thereof will be omitted.

(motor)
The motors 3 are arranged in series behind the engine 2 via the first clutch 5. The motor 3 is a permanent magnet type synchronous motor driven by three-phase alternating current. As shown in FIG. 2, the motor 3 is roughly composed of a motor case 31, a shaft 32, a rotor 33, a stator 34, and the like.

The motor case 31 is formed of a container having a cylindrical space in which the front end surface and the rear end surface are sealed, and is fixed to the vehicle body of the automobile 1. The rotor 33 and the stator 34 are housed in the motor case 31. The shaft 32 is rotatably supported by the motor case 31 with its front end and rear end protruding from the motor case 31.

The first clutch 5 is installed so as to be interposed between the front end portion of the shaft 32 and the output shaft of the engine 2. The first clutch 5 has a state in which the output shaft and the shaft 32 are connected (a state in which the first clutch 5 is connected and a connected state) and a state in which the output shaft and the shaft 32 are separated (the first clutch 5 is disconnected). It is configured to be switchable between the clutched state and the released state.

The second clutch 7 is installed so as to be interposed between the rear end portion of the shaft 32 and the input shaft of the transmission 8. In the second clutch 7, the state in which the shaft 32 and the input shaft of the transmission 8 are connected (the state in which the second clutch 7 is connected, the connected state) and the state in which the shaft 32 and the input shaft of the transmission 8 are connected are separated. It is configured to be switchable to a state (a state in which the second clutch 7 is disengaged, a state in which the second clutch 7 is released). Each of the first clutch 5 and the second clutch 7 is configured to be able to adjust the magnitude of the transmitted power in a state (partially connected state) between the connected state and the released state.

(Rotor)
The rotor 33 is composed of a columnar member formed by laminating a plurality of metal plates having a shaft hole in the center. The rotor 33 is integrated with the shaft 32 by fixing the intermediate portion of the shaft 32 to the shaft hole of the rotor 33.

A magnet 35 is installed on the outer peripheral portion of the rotor 33 over the entire circumference. The magnet 35 is configured such that a plurality of (8 in this example) magnetic poles 35a composed of S poles and N poles are alternately arranged at equal intervals in the circumferential direction. The magnet 35 may be composed of one cylindrical magnet having a plurality of magnetic poles 35a, or may be composed of a plurality of arc-shaped magnets constituting each magnetic pole 35a (in the illustrated example, a plurality of arc-shaped magnets). Consists of magnets).

Further, in the motor 3, the magnet 35 is configured so that the magnitude of the magnetic force can be changed to a large or small amount (magnetic force variable magnet). Usually, a magnet (permanent magnet) having a large coercive force (coercive force) and capable of holding the magnetic force for a long period of time is used for this type of motor 3. In the motor 3, a permanent magnet having a small holding force is used as the magnet 35 so that the magnetic force can be changed relatively easily.

There are various types of permanent magnets, such as ferrite magnets, neodymium magnets, samarium-cobalt magnets, and alnico magnets, and their holding powers are also various. The type and material of the magnet 35 can be selected according to the specifications and is not particularly limited.

In the automobile 1, a motor control device is configured so that the motor 3 can be made lightweight and compact by using the magnet 35. Details of the motor control device will be described later.

(Stator)
A cylindrical stator 34 is installed around the rotor 33 with a slight gap (inner rotor type). The stator 34 has a stator core 34a formed by laminating a plurality of metal plates, and a plurality of coils 36 formed by winding an electric wire around the stator core 34a.

The stator core 34a is provided with a plurality of teeth 34b that project radially inward, and a plurality of electric wires are wound in a predetermined order in a space (slot) formed between the teeth 34b (this figure). In the example, 12 coils 36 are formed (so-called concentrated winding). These coils 36 form a three-phase coil group composed of U-phase, V-phase, and W-phase having different phases of flowing currents. The coils of each phase are arranged in order in the circumferential direction.

In the present embodiment, the motor 3 having 8 poles and 12 slots has been illustrated, but the configuration of the motor 3 is not limited to this. The motor 3 may be configured with a larger number of poles and slots. For example, the motor 3 can be configured by 2 N times the magnetic pole 35a and 3 N times the slot (N is an integer).

In order to energize the coils 36, three connection cables 36a, 36a, 36a are led out from these coils 36 on the outside of the motor case 31. These connection cables 36a, 36a, 36a are connected to the battery 10 mounted on the vehicle via the inverter 6. In the case of the automobile 1, as the battery 10, a DC battery (low voltage battery) 10 having a rated voltage of 50 V or less, specifically 48 V, is used.

Therefore, unlike the hybrid vehicle of Patent Document 1 described above, the voltage is not high, so that the battery 10 itself can be made lightweight and compact. Moreover, since advanced measures against electric shock are not required, the insulating member and the like can be simplified, and the structure can be made even lighter and more compact. Therefore, since the vehicle weight of the automobile 1 can be suppressed, fuel consumption and power consumption can be suppressed.

The battery 10 supplies DC power to the inverter 6. The inverter 6 converts the DC power into three-phase alternating current and energizes the motor 3. As a result, an electromagnetic force is generated in each coil 36. The rotor 33 is rotationally driven by the attractive force and the repulsive force acting between the electromagnetic force and the magnetic force of the magnet 35, and the rotational power is output to the transmission 8 through the shaft 32 and the second clutch 7.

In the case of the automobile 1, the transmission 8 is a multi-stage automatic transmission (so-called AT). The transmission 8 has an input shaft at one end and an output shaft at the other end. A plurality of planetary gear mechanisms, clutches, brakes, and other transmission mechanisms are incorporated between these input shafts and output shafts.

By switching these transmission mechanisms, it is possible to switch between forward and reverse movements and to change the rotation speed between the input and output of the transmission 8 to be different. The output shaft of the transmission 8 is connected to the differential gear 9 via a propeller shaft 11 that extends in the front-rear direction of the vehicle body and is arranged coaxially with the output shaft.

A pair of drive shafts 13, 13 extending in the vehicle width direction and connected to the left and right drive wheels 4R, 4R are connected to the differential gear 9. The rotational power output through the propeller shaft 11 is distributed by the differential gear 9 and then transmitted to each drive wheel 4R through the pair of drive shafts 13 and 13. A brake 14 is attached to each of the wheels 4F, 4F, 4R, and 4R in order to brake the rotation thereof.

[Control system equipment]
In the automobile 1, each unit of the ECU 20, the MCU 21, the TCU 22, the BCU 23, and the GCU 24 described above is installed in order to control the traveling thereof according to the operation of the driver. Each of these units is composed of hardware such as a CPU, memory, and interface, and software such as a database and a control program.

The ECU 20 is a unit that mainly controls the operation of the engine 2. The MCU 21 is a unit that mainly controls the operation of the motor 3. The TCU 22 is a unit that mainly controls the operation of the first clutch 5, the second clutch 7, and the transmission 8. It is a unit that mainly controls the operation of the BCU 23 and the brake 14. The GCU 24 is an upper unit that is electrically connected to the ECU 20, the MCU 21, the TCU 22, and the BCU 23, and controls them comprehensively. The MCU 21 constitutes the main body of the "control device". Units such as the GCU 24 constitute a "control device" in cooperation with the MCU 21.

The engine rotation sensor 50 is attached to the engine 2, detects the rotation speed of the engine 2, and outputs it to the ECU 20. The motor rotation sensor 51 is attached to the motor 3, detects the rotation speed and the rotation position of the rotor 33, and outputs the rotation speed sensor 51 to the MCU 21. The current sensor 52 is attached to the connection cable 36a, detects the current value applied to each coil 36, and outputs the current value to the MCU 21.

The magnetic force sensor 53 is attached to the motor 3 and detects the magnetic force of the magnet 35 and outputs the magnetic force to the MCU 21. The accelerator sensor 54 is attached to an accelerator pedal (accelerator pedal 15) that the driver depresses when driving the automobile 1, and detects an accelerator opening corresponding to an output required for driving the automobile 1 to the ECU 20. Output.

Based on the signals of the detected values input from these sensors, each unit cooperates to control the drive system, so that the automobile 1 travels. For example, when the automobile 1 travels with the driving force of the engine 2, the ECU 20 controls the operation of the engine 2 based on the detected values of the accelerator sensor 54 and the engine rotation sensor 50.

Then, the TCU 22 controls so that the first clutch 5 and the second clutch 7 are in the connected state. When braking the automobile 1, the BCU 23 controls each brake 14. At the time of braking by regeneration, the TCU 22 controls the first clutch 5 to be in the released state or the partially engaged state, and controls the second clutch 7 to be in the engaged state. Then, the MCU 21 generates electricity with the motor 3 and controls so that the electric power is recovered by the battery 10.

<Motor control device>
The MCU 21 controls the automobile 1 to run by the rotational power of the motor 3 in a state where the motor 3 outputs independently or assists the output of the engine 2 as needed.

Specifically, the ECU 20 sets the rotational power of the engine 2 based on the detected values of the accelerator sensor 54, the engine rotation sensor 50, and the like. Along with this, the GCU 24 sets the required amount of rotational power of the motor 3 in a predetermined output range according to the output distribution ratio between the engine 2 and the motor 3 set in advance. The MCU 21 controls the motor 3 so that the required amount is output.

FIG. 3 shows the MCU 21 and its related main input / output devices. The MCU 21 is provided with a drive current control unit 21a and a magnetization current control unit 21b. The drive current control unit 21a has a function of controlling the drive of the motor 3, and changes the torque generated in the rotor 33 by controlling the drive current flowing through the coil 36. As a result, the motor 3 is made to output the required amount of rotational power.

On the other hand, the magnetization current control unit 21b has a function of increasing the power factor of the motor 3, and changes the magnetic force generated in the coil 36 by controlling the magnetization current flowing through the coil 36. By doing so, the magnetic force of the magnet 35 is changed. Specifically, the magnetic force of the magnet 35 is changed so that the magnetic force of the magnet 35 substantially matches the electromagnetic force generated in the coil 36 by the driving current.

The power factor is the ratio of active power (power actually consumed) to apparent power (power supplied to the motor 3). If the power factor is low, a large current must be applied to obtain the same output, which increases the size of the motor. Therefore, by increasing the power factor of the motor 3, the motor 3 can be made lightweight and compact. In addition, if the power factor is increased, the power generation during regeneration can also be increased.

In order to increase the power factor of the motor 3 to the upper limit, it is necessary to make the electromagnetic force generated by the coil 36 and the magnetic force of the permanent magnet substantially match (if the electromagnetic force and the magnetic force are substantially the same, the power factor is omitted. 1). On the other hand, in the case of a normal permanent magnet type motor, since the magnetic force of the permanent magnet is invariant, a permanent magnet having a power factor of about 1 is used in the most frequently used region output by the motor. There is.

That is, the type, material, structure, etc. of the permanent magnet are designed according to the specifications, and in the initial state of being shipped from the manufacturing factory, the permanent magnet is magnetized by the magnetic force.

In applications such as home appliances, the range in which the output of the motor is required is relatively limited, so even such motor characteristics do not pose a big problem. However, when driving the automobile 1, high frequency output is required in a very wide range. Therefore, such motor characteristics have problems such as high voltage of the battery and large size of the motor.

On the other hand, in this motor control device, a magnet 35 capable of changing the magnetic force is used, and the MCU 21 is provided with the magnetization current control unit 21b, so that the power factor can be improved and such a problem can be solved. It has become.

That is, when the load on the motor 3 changes, the magnetic force of the magnet 35 is changed according to the load. For example, at a medium load, the magnetic force of the magnet 35 is increased (enhanced) with respect to the magnetic force at a low load so that the power factor becomes approximately 1. At a low load, the magnetic force of the magnet 35 is reduced (demagnetization) with respect to the magnetic force at a medium load so that the power factor becomes approximately 1.

Specifically, data such as a map or a table that defines the output range of the rotational power of the motor 3 is preset in the MCU 21 based on the load and the rotation speed of the motor 3. The output range is divided into a plurality of areas. Then, in each of these regions, the magnetization current control unit 21b changes the magnetic force of the magnet 35 so that the power factor is suitable for that region. That is, the output range of the rotational power of the motor 3 is divided into a plurality of regions (magnetization regions) in which the magnetic force of the magnet 35 is different.

The magnetic force of the magnet 35 is preferably set to a magnetic force (load upper limit magnetic force) that substantially matches the electromagnetic force generated in the load upper limit region of the output range of the motor 3 in the initial state. Then, even with a high load, the power factor can be reduced to approximately 1 and increased. Therefore, in this case, since the motor 3 can be efficiently driven even with a high load, insufficient output can be suppressed even with a lightweight and compact motor 3, and stable running can be realized.

Then, at a medium load or a low load, the electromagnetic force becomes smaller according to the load, but with the magnet 35, the power factor can be reduced to approximately 1 by demagnetizing according to the electromagnetic force. Therefore, in this case, the power factor can be increased in substantially the entire output range of the motor, and the motor 3 can be driven efficiently.

As described above, in this motor control device, the power factor of the motor 3 is increased by changing the magnetic force of the magnet 35, so that it is possible to avoid increasing the voltage of the battery and increasing the size of the motor.

In the motor control device of the present embodiment, the control for changing the magnetic force of the magnet 35 (magnetic force change control) is accurate regardless of whether the vehicle 1 is stopped or the vehicle 1 is running. It is devised so that it can be executed at a high price. Details of these will be described later.

<Motor control by motor control device>
FIG. 4 shows a simplified system diagram of the motor control device. FIG. 5 shows an example of the control of the motor 3 performed by the MCU 21. A specific control flow of the motor 3 will be described with reference to these. The motor 3 is controlled by vector control using a ^{torque current command Iq *} corresponding to the drive current and an exciting current command Id ^{* corresponding to the magnetization current.}

When the automobile 1 is in a state where the vehicle 1 can travel, the MCU 21 always inputs a detected value from the current sensor 52, the motor rotation sensor 51, and the magnetic force sensor 53 (step S1). Similarly, in the ECU 20, the detected value is constantly input from the accelerator sensor 54 and the engine rotation sensor 50.

The GCU 24 acquires the detected value of the accelerator sensor 54 from the ECU 20 and sets the required amount of the rotational power of the motor 3 according to the preset distribution ratio of the output between the engine 2 and the motor 3. The GCU 24 outputs a command (torque command value T ^* ) to output the torque corresponding to the required amount to the MCU 21.

^{When the torque command value T *} is input (Yes in step S2), the MCU 21 (drive current control unit 21a) outputs a command (drive current command) that outputs the amount of change in the drive current (torque current component) that generates the torque. The arithmetic processing of the value Idq ^* ) is executed (step S3). Further, the MCU 21 (magnetization current control unit 21b) calculates ^{a command (magnetization state command value Φ *} ) that outputs an optimum magnetic force value corresponding to the magnetization region based on ^{the torque command value T * and the rotation speed of the motor 3.} The process is executed (step S4). ^{Then, the magnetization current control unit 21b is a command (magnetic current command value Idq *} ) that outputs a torque current component corresponding to the amount of change in the magnetic force of the magnet 35 based on the magnetic force of the magnet 35 and the magnetization state command value Φ ^*. Arithmetic processing is executed (step S5).

The MCU 21 determines whether or not it is necessary to change the magnetic force of the magnet 35 based on the calculated drive current command value Idq ^* and the magnetic force current command value Idq ^{* (step S6).} For example, when the required torque is output and the magnet is shifted to a different magnetization region, it is determined that the magnetic force of the magnet 35 needs to be changed. Even if the required torque is output, if it is located in the same magnetization region, it is determined that the change in the magnetic force of the magnet 35 is unnecessary.

Then, when it is determined that the change of the magnetic force of the magnet 35 is unnecessary, the MCU 21 determines whether or not the output torque is larger than the torque T1 in which the motor 3 runs idle (step S7). Then, when the output torque is larger than the torque T1, the MCU 21 controls the motor 3 by ordinary vector control.

That is, the drive current control unit 21a executes arithmetic processing of ^{a command (voltage command value Vuvw *} ) output for performing PWM control based on the detected values of the current sensor 52 and the motor rotation sensor 51 by current control. (Step S8). Then, the switching command value is calculated by the PWM control (step S9).

By outputting the switching command value to the inverter 6 through the driver circuit, a plurality of switching elements are on / off controlled inside the inverter 6. As a result, a predetermined three-phase alternating current (driving current) is energized in each coil group, the motor 3 rotates, and the required torque is output (step S10).

On the other hand, when the MCU 21 determines that it is necessary to change the magnetic force of the magnet 35 (No in step S6), the magnetization current control unit 21b executes the magnetic force change control (step S11).

Further, even if the MCU 21 determines that the change of the magnetic force of the magnet 35 is unnecessary, if the output torque is determined to be equal to or less than the torque T1 in which the motor 3 runs idle (No in step S7), the magnetization current control unit The magnetic force change control is executed by 21b (step S11).

When the motor 3 is idle, that is, when the required amount of rotational power of the motor 3 becomes almost 0 (zero), the magnetic force of the magnet 35 is reset and the magnetic force in the initial state (load upper limit magnetic force). Is changed to. In the case of the automobile 1, for example, the accelerator pedal 15 may be depressed at once from an idling state or a stopped state to accelerate suddenly. If the load upper limit magnetic force is changed during idle operation, the motor 3 can be appropriately driven even when such sudden acceleration is performed.

<Magnetic force change control>
As described above, a magnet 35 capable of changing the magnetic force is used in the motor 3. Then, the MCU 21 (magnetization current control unit 21b) executes control for changing the magnetic force of the magnet 35 (magnetic force change control). In order to change the magnetic force of the magnet 35, although it is a short time, a strong magnetic force (magnetism) is formed between each magnetic pole 35a of the magnet 35 and the coil 36 so that a magnetic field larger than that during normal driving is formed. Magnetic force) needs to be applied.

The magnetizing magnetic force varies depending on the performance of the magnet 35, but for example, a magnetic force several to several tens of times the magnetic force held by the magnet 35 is used. Then, once the magnetic force of the magnet 35 is changed by such a strong magnetic force, even if a slightly strong magnetic force acts on the magnet 35, it is hardly affected by the magnetic force. Therefore, the magnetic force of the changed magnetic pole 35a is maintained to the extent that the motor 3 is normally driven.

In the magnetic force change control, the magnetic pole 35a (control target magnetic pole) that is the target of the magnetic force change control and the coil 36 (control target coil) that is the target of the magnetic force change control are arranged so as to face each other. Then, among the currents flowing through the control target coil, the current component (magnetization current) that generates a magnetic force in the radial direction in the control target coil is adjusted.

For example, in the case of magnetizing, a large pulse-shaped magnetization current is passed through the control target coil so that a strong magnetic flux is generated in the same direction as the magnetic flux of the control target magnetic pole. In the case of demagnetization, a large pulse-shaped magnetization current is passed through the control target coil so that a strong magnetic flux is generated in the direction opposite to the magnetic flux of the control target magnetic pole.

At that time, if the magnetic field applied to the control target magnetic pole is biased, the magnetization of each portion of the magnetic pole 35a may vary, and the magnetization distribution of the magnetic pole 35a may become non-uniform.

That is, the positional relationship between the control target magnetic pole and the control target coil changes every moment as the rotor 33 rotates. Therefore, in that case, the magnetic field distribution formed when a strong magnetic field is generated in the controlled coil also changes every moment. Therefore, the timing of magnetization that generates a strong magnetic field in the coil to be controlled is shifted, and the magnetic distribution of the magnetic poles tends to be non-uniform. As a result, the motor 3 cannot properly output the rotational power, and the motor output decreases.

In the case of the automobile 1, unlike home appliances that do not move, it is not always possible to control the magnetic force change while the motor is stable. The motor sways when it is running, and even when it is stopped, the motor sways if the engine is running or the occupants move. Also, the posture of the motor is not constant. If the magnetic field change control is executed in a state where the motor is swaying or the posture is unstable, the magnetic field applied to the control target magnetic pole is likely to be disturbed, so that the accuracy of the magnetic force change is lowered. Therefore, in the case of the motor 3 mounted on the automobile 1, it is difficult to uniformly change the magnetic force of the magnetic pole 35a.

On the other hand, in this motor control device, the magnetic force change control is devised so that the magnetic force change control can be executed with high accuracy in both the state where the automobile 1 is stopped and the state where the automobile 1 is running.

Specifically, the MCU 21 performs magnetic force change control (static magnetic force change control) suitable for performing the motor 3 in a state of being separated from the drive system, and performing the motor 3 in a state of not being separated from the drive system. Magnetic force change control (dynamic magnetic force change control) suitable for the above is configured to be feasible. Then, the MCU 21 selects and executes any one of these controls.

The static magnetic force change control is mainly executed in a state where the automobile 1 is stopped. The state may be not only a state in which the engine 2 is not operating, but also a state in which the engine 2 is operating, such as an idling state. Further, when the automobile 1 is traveling by inertia, the execution can be performed even when the automobile 1 is not stopped.

The dynamic magnetic force change control is mainly executed in a state where the automobile 1 is running. Dynamic magnetic force change control can be executed even when the automobile 1 is stopped. However, as will be described later, it is preferable to execute static magnetic force change control when the automobile 1 is stopped from the viewpoints of accuracy of magnetic force change and power consumption of the battery 10.

[Static magnetic force change control]
In the static magnetic force change control, the magnetic force change control is executed in a state where the magnetic pole 35a and the coil 36 are aligned and the rotation of the rotor 33 is substantially stopped. Specifically, the MCU 21 (drive current control unit 21a) executes control (alignment control) to align the positions of both the control target magnetic pole and the control target coil, and the control target magnetic pole and the control target coil are aligned. In this state, the MCU 21 (magnetization current control unit 21b) executes the magnetic force change control.

Prior to performing the alignment control, the motor 3 is preferably separated from the drive system. That is, the TCU 22 disconnects the first clutch 5 and the second clutch 7. By doing so, the motor 3 is made independent of both the engine 2 and the transmission 8. As a result, the rotor 33 and the shaft 32 are in a free state, that is, in a rotatable state. As a result, the alignment between the control target magnetic pole and the control target coil becomes easy, and the accuracy of the alignment control can be improved.

In the alignment control, the rotor 33 is rotated so that the control target magnetic pole and the control target coil face each other and the axis of the control target magnetic pole and the axis of the control target coil are close to each other. The number of control target magnetic poles and control target coils that are simultaneously aligned and controlled may differ depending on the configuration of the motor 3.

The static magnetic force change control will be described with reference to FIG. For convenience of explanation, a 4-pole 6-slot motor with a simplified configuration is shown. Reference numeral Jp indicates the axis of the magnetic pole 35a, and reference numeral Jc indicates the axis of the coil 36. The axis Jp of the magnetic pole 35a is a line that bisects the magnetic pole 35a through the center of rotation when viewed from the direction in which the shaft 32 extends (rotational axis direction). The axis Jc of the coil is a line that bisects the coil 36 through the center of rotation when viewed from the direction of the rotation axis.

For example, it is assumed that the rotor 33 is located at the position shown in the upper part of FIG. 6 when the static magnetic force change control is started. The rotor 33 may be stopped or rotating. When the coil 36 of the U-phase coil group is used as the control target coil and the N pole magnetic pole 35a is used as the control target magnetic pole, the MCU 21 (drive current control unit 21a) receives a signal (rotor) input from the motor rotation sensor 51. The rotor 33 is rotated by a predetermined angle based on the rotation position information of the 33). By doing so, as shown in the middle figure of FIG. 6, the MCU 21 positions both the controlled magnetic pole and the controlled coil so that the axis Jc of the controlled coil and the axis Jp of the controlled magnetic pole are close to each other. To match.

Preferably, the positions are aligned so that the two axes Jc and Jp substantially coincide with each other. As a result, the displacement of the positional relationship between the control target magnetic pole and the control target coil can be prevented, the deviation of the magnetic field applied to the control target magnetic pole can be reduced, and the optimum magnetizing timing can be secured. At this time, if the motor 3 is separated from the drive system, stable positioning can be achieved and the influence of external factors such as vibration can be suppressed. Therefore, the accuracy of the alignment control is improved.

At this time, at the start of the alignment control, the alignment control is executed for the coil 36 having the phase in which the axis Jc is closest to the axis Jp of the control target magnetic pole among the plurality of magnetic poles 35a. It is preferable to do so. When the rotor 33 is rotating, the alignment control is executed for the coil 36 having the phase in which the axis Jc is closest to the axis Jp of the control target magnetic pole in the rotation direction. More preferred. Then, the rotation of the rotor 33 can be minimized. Therefore, the time required for the alignment control can be shortened, and the power required for the alignment control can also be reduced.

For example, it is assumed that the rotor 33 that is not rotating is at the position shown in the upper figure of FIG. 6 at the start of the alignment control. In that case, when the north pole 35a of the N pole is set as the control target magnetic pole, the axis Jc of the coil 36 of the U-phase coil group is located closest to the axis Jp of the control target magnetic pole. Therefore, in this case, it is preferable to rotate the rotor 33 to execute the alignment control as shown in the illustrated example.

Further, in the same case, when the magnetic pole 35a of the S pole is set as the control target magnetic pole, the axis Jc of the coil 36 of the V-phase coil group is located closest to the axis Jp of the control target magnetic pole. Therefore, in this case, it is preferable to rotate the rotor 33 clockwise to execute the alignment control.

Then, in a state where the control target magnetic pole and the control target coil are aligned in this way, the MCU 21 (magnetization current control unit 21b) is pulsed to the U-phase coil group, which is the control target coil, with a predetermined strength. Control so that the magnetization current flows. Since the axis Jp of the control target magnetic pole and the axis Jc of the control target coil are close to each other (substantially coincide with each other), the magnetic field formed by the magnetization current flowing through the control target coil is represented by a broken line in the middle figure of FIG. As shown in the above, it is applied in a well-balanced manner with respect to the control target magnetic pole. Therefore, the magnetic pole to be controlled can be magnetized substantially uniformly.

In the case of the motor of the example, the two magnetic poles (N poles) 35a and 35a are simultaneously aligned with the U-phase coil group, and the magnetic force change control is executed. Then, in the case of the motor shown in the figure, it is necessary to change the magnetic force of the remaining two magnetic poles (S poles) 35a and 35a. Therefore, these two magnetic poles 35a and 35a become new control target magnetic poles.

The MCU 21 (drive current control unit 21a) further rotates the rotor 33 by a predetermined angle based on the signal input from the motor rotation sensor 51. By doing so, as shown in the lower figure of FIG. 6, the MCU 21 has the axis Jp of the new control target magnetic pole and the control target coil (the coil 36 having the phase closest to the new control target magnetic pole). In the illustrated example, the positions of both the control target magnetic pole and the control target coil are aligned so that the axes Jc of the W phase or V phase coil 36) are close to each other (substantially coincide with each other).

Then, the MCU 21 (magnetization current control unit 21b) executes the magnetic force change control using the W-phase coil 36 in the illustrated example, and also changes the magnetic force of these new controlled magnetic poles. When the number of magnetic poles is larger, the alignment control and the magnetic force change control are executed for all the magnetic poles 35a, and the MCU 21 repeats such a series of processes until the magnetic forces of all the magnetic poles 35a are changed. Run.

In such a series of processes, when the execution of the magnetic force change control is started for any of the magnetic poles 35a, the clutch engagement is prohibited until the execution of the magnetic force change control for all the magnetic poles 35a is completed. Is preferable.

That is, even if the GCU 24 outputs an instruction to connect the first clutch 5 and / or the second clutch 7, the MCU 21 changes the magnetic force of all the magnetic poles 35a after the change of the magnetic force of the magnetic poles 35a is started. Until the end, the process is prioritized and executed.

If the first clutch 5 and / or the second clutch 7 is engaged before the execution of the magnetic force change control for all the magnetic poles 35a is completed, an external force acts on the rotor 33, so that the alignment control becomes unstable. , High-precision magnetic force change control cannot be performed. Further, if the magnetic force change control is interrupted and the motor 3 is driven in that state, the magnetic poles 35a having different magnetic forces are mixed, so that the motor 3 does not function properly. Therefore, there is a possibility that the motor 3 cannot output the rotational power required by the MCU 21.

On the other hand, when the change of the magnetic force of all the magnetic poles 35a is completed, the motor 3 functions properly. Therefore, the motor 3 can stably output the rotational power required by the MCU 21.

Such static magnetic force change control is effective when the automobile 1 is stopped. In the case of the automobile 1, unlike home appliances that can always receive a constant power supply from a commercial power source, the power source is limited to the battery 10. Moreover, the battery 10 of the automobile 1 is a low voltage battery. Since a large current is required in the magnetic force change control, in the case of the automobile 1, there is a problem that the battery 10 is rapidly consumed.

When the automobile 1 is stopped, regeneration using traveling is not possible, so that the battery 10 cannot be charged unless the engine 2 is used to generate electricity or an external power source is used. In that respect, in the static magnetic force change control, the magnetic force can be changed in the optimum state for each magnetic pole 35a, so that the magnetic force can be changed by one magnetic force change control with the necessary and minimum magnitude of the magnetization current. Can be changed appropriately. Therefore, since the power consumption can be minimized, the sudden consumption of the battery 10 can be suppressed.

[Dynamic magnetic force change control]
In the dynamic magnetic force change control, the magnetic force change control is executed in the process in which the predetermined coil 36 passes through the magnetic pole 35a while the rotor 33 is rotating. Specifically, when the rotor 33 is rotating and the coil to be controlled passes from one end to the other end in the circumferential direction of the magnetic pole to be controlled, the MCU 21 (magnetization current control unit 21b) executes magnetic force change control.

Since the dynamic magnetic force change control is performed in the state where the rotor 33 is rotating, it can be executed even in the state where the automobile 1 is running. Therefore, there is an advantage that there are few restrictions on execution as compared with static magnetic force change control. For example, when the automobile 1 is traveling by driving only the engine 2, when the automobile 1 is traveling with the motor 3 assisting the driving of the engine 2, the automobile 1 is traveling by driving only the motor 3. In any case, dynamic magnetic force change control can be performed. Further, even when the automobile 1 is stopped, it can be executed by rotating the rotor 33.

In particular, in the case of dynamic magnetic force change control, the magnetic force of the magnet 35 can be changed while the motor 3 outputs rotational power to the wheels, so that normal control of the motor 3 such as separating the motor 3 from the drive system can be performed. There is an advantage that it does not have to be greatly restricted. Therefore, it is possible to avoid complication of control.

The dynamic magnetic force change control will be described with reference to FIG. 7. For example, it is assumed that the rotor 33 is rotating counterclockwise as shown in the upper part of FIG. 7 when the dynamic magnetic force change control is started. When the coil 36 of the U-phase coil group is the control target coil and the magnetic pole 35a (N pole) is the control target magnetic pole, the MCU 21 (magnetization current control unit 21b) receives a signal (rotor) input from the motor rotation sensor 51. Based on the rotation position information and the number of rotations of 33), the time (magnetization time) required for the control target magnetic pole to pass through one control target coil is calculated.

Then, as shown in the middle figure of FIG. 7, the rotor 33 rotates, and one end portion in the circumferential direction of the control target magnetic pole (the end portion located on the traveling side in the rotation direction, the advance angle side end portion Epf) becomes , A position that coincides with one end (substantially the tip of the teeth 34b) in the circumferential direction (the end located on the opposite side of the rotation direction, the retard side end Ecr) in the radial direction. When it reaches, the MCU 21 (magnetization current control unit 21b) controls the U-phase coil group, which is the control target coil, so that the magnetization current starts to flow at a predetermined intensity, and starts time measurement.

Then, when the magnetization time elapses, as shown in the lower figure of FIG. 7, the rotor 33 further rotates, and the other end (retard side end Epr) in the circumferential direction of the control target magnetic pole is controlled. It reaches a position that coincides with the other end (advance side end Ecf) in the circumferential direction of the coil in the radial direction. That is, the control target magnetic pole passes through the control target coil.

During that time, the MCU 21 (magnetization current control unit 21b) controls so that the magnetization current of a predetermined intensity continuously flows to the control target coil, and ends the control when the control target magnetic pole passes through the control target coil. ..

While the controlled magnetic pole passes through the controlled coil, a constant magnetizing magnetic force is applied to the controlled magnetic pole from the controlled coil. Therefore, even if the magnetic field changes due to the rotation of the rotor 33, it is possible to suppress the non-uniformity of the magnetization distribution of the magnetic poles to be controlled.

While the magnetization current is applied to the coil to be controlled, the MCU 21 (drive current control unit 21a) can control so that a predetermined drive current flows through each coil group. Therefore, the rotational power can be output from the motor 3 even during the execution of the dynamic magnetic force change control. However, during that time, the rotational power output from the motor 3 also changes with the change in the magnetic force of the magnetic pole to be controlled.

When performing dynamic magnetic force change control, it is preferable to control the rotation speed of the rotor 33 to be constant. For example, the MCU 21 (drive current control unit 21a) controls the rotor 33 to rotate at a predetermined rotation speed for a certain period of time (constant rotation control). Then, while the rotor 33 is rotating at a constant rotation speed, dynamic magnetic force change control is executed. If the rotation speed of the rotor 33 is constant, the calculation of the magnetization time becomes simple. Disturbance of the magnetic field applied to the controlled magnetic pole can be further suppressed. Therefore, the accuracy of magnetic force change control is further improved.

Further, it is preferable to execute the dynamic magnetic force change control when the rotation speed of the rotor 33 is as low as possible. That is, it is preferable that the dynamic magnetic force change control is executed when the rotation of the rotor 33 is less than a predetermined rotation speed and is not executed when the rotation speed is equal to or more than a predetermined rotation speed. Since the magnetization time becomes shorter as the rotation speed of the rotor 33 increases, there is a possibility that the required magnetic force cannot be changed by one magnetization. In addition, the magnetization distribution of the magnetic pole 35a tends to be non-uniform. On the other hand, as the rotation speed of the rotor 33 decreases, the magnetization time becomes longer, so that the amount of magnetic force that can be changed by one magnetic force change control increases, and the magnetization distribution of the magnetic pole 35a tends to be uniform. Therefore, the accuracy of magnetic force change control is improved.

The predetermined number of rotations, which is a determination standard, may be appropriately set according to the specifications of the motor 3. For example, the region of the outputable rotation speed of the motor 3 may be divided into three equal parts of low, medium and high, and an arbitrary rotation speed in the middle region may be set as a predetermined rotation speed. Further, an arbitrary rotation speed in the low region may be set as a predetermined rotation speed.

In the case of the motor 3 of the illustrated example, the two magnetic poles (N poles) 35a and 35a are simultaneously aligned with the U-phase coil group, and the magnetic force change control is executed. Then, in the case of the motor 3 in the illustrated example, it is necessary to change the magnetic force of the remaining two magnetic poles (S poles) 35a and 35a. Therefore, these two magnetic poles 35a become new control target magnetic poles.

Using the coil 36 of the U-phase coil group as the control target coil, the magnetic force change control can be performed for the new control target magnetic pole by the same processing. That is, in the process in which the magnetic pole 35a of the S pole passes through the coil 36 of the U-phase coil group, a magnetization current is applied to the U-phase coil group. However, in the case of dynamic magnetic force change control, it is preferable to collectively change the magnetic force of all the magnetic poles 35a by using another coil group.

The upper figure of FIG. 8 shows a state in which magnetic force change control is being executed for the magnetic pole 35a (N pole). When the coil to be controlled (U phase) is passing through the magnetic pole to be controlled, the magnetic pole 35a of the S pole starts to pass through the coil 36 of the coil group of the W phase. That is, the coil 36 of the W-phase coil group can be used as the control target coil, and the magnetic pole 35a (S pole) can be used as the control target magnetic pole.

Therefore, in the MCU 21 (magnetization current control unit 21b), the advance angle side end Epf of the control target magnetic pole (S pole) is radial to the retard side end Ecr of the control target coil (W phase coil 36). When the position corresponding to the above is reached, the magnetization current is controlled to start flowing at a predetermined intensity in the W phase coil group as well as the U phase coil group, and the time measurement is started.

Then, the magnetization time elapses, and as shown in the lower figure of FIG. 8, the retard side end Epr of the control target magnetic pole (S pole) becomes the advance side end of the control target coil (W phase coil 36). The MCU 21 (magnetization current control unit 21b) controls the magnetization current of a predetermined intensity to continuously flow through the control target coil (W-phase coil 36) until it reaches a position that coincides with the part Ecf in the radial direction. ..

In this way, by executing the magnetic force change control using two different coil groups, the magnetic force of all the magnetic poles 35a can be changed at once. Since the magnetic forces of all the magnetic poles 35a can be changed in a short time, it is advantageous in terms of time. Since the magnetization time can be shared, the arithmetic processing can be simplified.

In the case of dynamic magnetic force change control, the magnetization time for applying the magnetizing magnetic force to the controlled magnetic pole changes depending on the rotation speed of the rotor 33. And, as described above, when the rotation speed is high, there is a possibility that the required magnetic force cannot be changed by one magnetization. Therefore, in such a case, it is preferable that the MCU 21 (magnetization current control unit 21b) executes dynamic magnetic force change control a plurality of times with respect to the same controlled magnetic pole.

That is, the MCU 21 (magnetization current control unit 21b) determines whether or not the magnet 35 has the required magnetic force (optimal magnetic force value) based on the signal input from the magnetic force sensor 53. Then, the MCU 21 (magnetization current control unit 21b) executes dynamic magnetic force change control a plurality of times with respect to the same controlled magnetic pole until the magnet 35 reaches the required magnetic force.

By doing so, even if the magnetic force of the magnetized magnetic pole 35a varies due to the variation in the rotation speed of the rotor 33, it can be changed to the required magnetic force. In particular, in the case of dynamic magnetic force change control, unlike static magnetic force change control, the magnetization distribution tends to be non-uniform because it is affected by harmonics. On the other hand, if it is magnetized a plurality of times, the influence of harmonics can be reduced, so that the uniformity of the magnetization distribution of the magnetic pole 35a can be improved.

If dynamic magnetic force change control is continuously executed using the coils of each phase of U, V, and W and the magnetic forces of all the magnetic poles 35a are changed at once, even if it is multiple times, it will be a short time. You can do it with.

Since the dynamic magnetic force change control has a lower magnetization efficiency than the static magnetic force change control, the power consumption is larger than that of the static magnetic force change control. Therefore, the power of the battery 10 suddenly drops below the limit, which may cause a power trouble. Therefore, when the automobile 1 is stopped, it is preferable to execute static magnetic force change control.

On the other hand, in the case of dynamic magnetic force change control, since it can be executed while the automobile 1 is running or the engine 2 is being driven, the battery 10 can be charged by the power of the engine 2 or the regeneration during braking. Therefore, even if the power consumption is large, the power of the battery 10 can be replenished by charging, so that the power reduction of the battery 10 can be prevented.

[Specific example of magnetic force change control]
FIG. 9 illustrates the main processing of magnetic force change control. The MCU 21 determines whether or not the automobile 1 is stopped via the GCU 24 (step S20). In the case of this example, the MCU 21 executes static magnetic force change control when the automobile 1 is stopped, and executes dynamic magnetic force change control when the automobile 1 is traveling.

When it is determined that the automobile 1 is stopped, the MCU 21 determines the control target magnetic pole (step S21). Then, when the control target magnetic pole is determined, the MCU 21 executes the alignment control (step S22).

As shown in FIG. 10, when the MCU 21 starts the alignment control, the GCU 24 executes the control to disengage the clutch through the TCU 22 (step S31). Specifically, the first clutch 5 and the second clutch 7 are switched to the released state. As a result, the motor 3 is separated from the drive system and becomes an independent state.

The MCU 21 subsequently determines the coil to be controlled (step S32). Specifically, at the start of the alignment control, the coil 36 whose axis Jc is closest to the axis Jp of the control target magnetic pole is selected as the control target coil. Then, when the coil to be controlled is selected, the MCU 21 receives a command value (positioning current command) of a current that rotates the rotor 33 by an angle required for alignment based on the signal input from the motor rotation sensor 51. The calculation of Iuvw ^* ) is performed (step S33).

The MCU 21 controls the inverter 6 based on the alignment current command Iuvw ^* , outputs the alignment current Iuvw to the motor 3, and rotates the rotor 33 by a predetermined angle (step S34). Then, in the MCU 21, whether or not the position of the rotor 33 is appropriate based on the signal input from the motor rotation sensor 51, that is, the axis Jp of the control target magnetic pole and the axis Jc of the control target coil substantially match. It is determined whether or not the state is in the aligned state (aligned state) (step S35). The MCU 21 outputs the alignment current Iuvw to the motor 3 until the position of the rotor 33 is determined to be appropriate (No in step S35).

When the position of the rotor 33 is determined to be appropriate, the MCU 21 can execute static magnetic force change control. After that, the MCU 21 determines whether or not the static magnetic force change control is completed (step S36), and controls so that the aligned state is maintained until the static magnetic force change control is completed (step S36). No in step S36).

Then, when the static magnetic force change control is completed, the GCU 24 executes the control to engage the clutch through the TCU 22 (step S37). Specifically, when the execution of the static magnetic force change control for all the magnetic poles 35a is completed, the first clutch 5 and the second clutch 7 are switched to the connected state. Thereby, the motor 3 is connected to the drive system.

As shown in FIG. 9, when the alignment control is executed and the control target magnetic pole and the control target coil are aligned, the MCU 21 executes static magnetic force change control (step S23).

As shown in FIG. 11, when the static magnetic force change control is started, the MCU 21 executes the magnetization current control (step S40). Specifically, the MCU 21 applies a predetermined pulsed magnetization current to the control target coil through the inverter 6 according to either the magnetizing amount or the demagnetizing amount required for the controlled magnetic pole. As a result, when the magnetic force of the magnetic force to be controlled reaches the obtained value (optimum magnetic force value), the static magnetic force change control is completed. Whether or not the magnetic force of the control target magnetic pole has reached the required value can be determined based on the signal input from the magnetic force sensor 53.

As shown in FIG. 9, such static magnetic force change control is repeatedly executed until the magnetic force changes of all the magnetic poles 35a are completed (step S24).

On the other hand, in FIG. 9, when it is determined that the automobile 1 is not stopped, that is, the automobile 1 is traveling, the MCU 21 executes the dynamic magnetic force change control. For example, it is assumed that the motor 3 is rotating while being connected to the drive system, and the motor 3 is outputting rotational power while assisting the engine 2 or independently.

FIG. 12 shows an example of dynamic magnetic force change control. The MCU 21 specifies the rotation speed of the rotor 33 based on the signal input from the motor rotation sensor 51, and calculates a command value indicating the magnetization time (step S50). The MCU 21 also identifies the rotation position of the rotor 33 based on the signal input from the motor rotation sensor 51, and the advance angle side end Epf of the control target magnetic pole has a diameter with the retard side end Ecr of the control target coil. The control (standby control) that waits until the position corresponding to the direction is reached is executed (step S51). As the control target magnetic pole and the control target coil, it is preferable to select the magnetic pole 35a and the coil that are closest to each other in the rotation direction when the dynamic magnetic force change control is started.

Then, when the advance angle side end Epf of the control target magnetic pole reaches a position that coincides with the retard side end Ecr of the control target coil in the radial direction, the MCU 21 sends the coil group constituting the control target coil to the coil group. The time measurement is started by controlling the magnetization current to start flowing at a predetermined intensity (step S52). Then, the application of the magnetization current is continued until the magnetization time elapses.

At this time, the MCU 21 continuously executes such dynamic magnetic force change control using a plurality of different coil groups. By doing so, the MCU 21 changes the magnetic forces of all the magnetic poles 35a at once.

The magnetic force of the magnetic pole to be controlled changes by applying the magnetization current. Along with this, the torque generated in the rotor 33 also changes. As a result, the rotational power output from the motor 3 also changes, so that the traveling of the automobile 1 may be disturbed.

On the other hand, in the case of the automobile 1, control for adjusting the torque by using the engine 2, the brake 14, and / or the clutches 5 and 7 so as to suppress the influence of such a torque change (torque adjustment control). ) Is executed (step S53). For example, when the magnetic pole 35a is demagnetized, the torque of the rotor 33 changes slightly, so that the engine 2 is controlled to output the rotational power corresponding to the torque. When the magnetic pole 35a is magnetized, the torque of the rotor 33 changes significantly, so that the brake 14 controls the rotational power corresponding to the change. Then, with or separately from these controls, the influence of the torque change is affected by adjusting the magnitude of the transmitted power by making each of the first clutch 5 and the second clutch 7 partially connected. It can be suppressed.

Then, when the magnetization time elapses and the magnetic pole to be controlled passes through the coil to be controlled, the application of the magnetization current and the standby control are terminated (step S54). The MCU 21 determines whether or not the magnet 35 has a required magnetic force (optimal magnetic force value) based on the signal input from the magnetic force sensor 53 (step S55). Then, the MCU 21 repeatedly executes the dynamic magnetic force change control until the magnetic force of the magnet 35 reaches the optimum magnetic force value (No in step S55).

A large current is required to execute such magnetic force change control. Therefore, in the case of the automobile 1, there is a problem that the battery 10 is rapidly consumed. In particular, in the case of a low-voltage battery, since the voltage is low even in a fully charged state, voltage abnormalities may occur frequently.

Therefore, in this automobile 1, the execution of each of the static magnetic force change control and the dynamic magnetic force change control is restricted based on the voltage value of the battery 10 (magnetization execution limit control). Specifically, the MCU 21 is set in advance with a first lower limit value V1 corresponding to dynamic magnetic force change control and a second lower limit value V2 corresponding to static magnetic force change control.

Since the static magnetic force change control can magnetize the magnet 35 more efficiently than the dynamic magnetic force change control, the power consumption can be reduced. Therefore, the first lower limit value V1 is higher than the second lower limit value V2 (V1> V2). The values of the first lower limit value V1 and the second lower limit value V2 can be appropriately selected according to the specifications of the motor 3 and the contents of the restrictions.

FIG. 13 shows an example of the magnetization execution limitation control. While driving the automobile 1, the MCU 21 constantly determines whether or not the voltage of the battery 10 is equal to or higher than the first lower limit value V1 (step S60). When the voltage of the battery 10 is equal to or higher than the first lower limit value V1 such as when the battery 10 is fully charged, even dynamic magnetic force change control with large power consumption can be executed without any problem, so that the magnetization execution is limited. No control is taken.

On the other hand, when the voltage of the battery 10 is less than the first lower limit value V1, the execution of the dynamic magnetic force change control is restricted (step S61). For example, execution of dynamic magnetic force change control is prohibited, and the number of times of execution is limited. However, static magnetic force change control does not limit its execution because it consumes less power.

Further, when the voltage of the battery 10 drops, a voltage abnormality may occur frequently even in static magnetic force change control. Therefore, the MCU 21 also determines whether or not the voltage of the battery 10 is equal to or higher than the second lower limit value V2 (step S62). Then, when the voltage of the battery 10 is less than the second lower limit value V2, the execution of the static magnetic force change control is also restricted (step S63). For example, execution of static magnetic force change control is prohibited, and the number of times of execution is limited.

If the voltage of the battery 10 is increased by charging the battery 10, the restriction of each magnetic force change control is released according to the degree of the voltage increase. Therefore, according to this motor control device, the occurrence of voltage abnormality can be suppressed, so that the automobile 1 can be stably driven.

The motor control device according to the disclosed technology is not limited to the above-described embodiment, and includes various other configurations.

For example, in the above-described embodiment, the application to a hybrid vehicle has been described as an example, but it may be an electric vehicle traveling only by a motor, or a two-wheeled vehicle such as a motorcycle or an electric bicycle. The disclosed technology can be applied not only to such moving objects but also to non-moving objects.

The configuration of the control device can be changed according to the specifications. For example, the control device may be configured by only one unit, or a plurality of units may be combined to form the control device as in the embodiment. The configuration of the motor is the same.

1 Automobile 2 Engine 3 Motor 4 Wheel 4R Drive wheel 5 1st clutch 6 Inverter 7 2nd clutch 8 Transmission 10 Battery 20 Engine control unit (ECU)
21 Motor control unit (MCU)
21a Drive current control unit 21b Magnetization current control unit 22 Transmission control unit (TCU)
23 Brake control unit (BCU)
24 Comprehensive Control Unit (GCU)
33 Rotor 34 Stator 35 Magnet (Variable magnetic force magnet)
35a magnetic pole 36 coil

Claims (8)

A magnet is installed so that a plurality of magnetic poles are lined up in the circumferential direction, and a rotor that outputs rotational power and a stator in which a plurality of coils facing the magnet with a gap are arranged so as to be lined up in the circumferential direction. With a motor and
A control device having a magnetization current control unit that controls the magnetization current flowing through the coil and changes the magnetic force generated in the coil.
With
The control device is
When the rotor is rotating so that a predetermined coil in the plurality of coils passes from one end to the other end in the circumferential direction of the predetermined magnetic poles in the plurality of magnetic poles, the magnetization current control unit causes the magnetization current control unit to pass. A motor control device that executes magnetic force change control that changes the magnetic force of the magnet by controlling the magnetization current. In the motor control device according to claim 1,
The motor control device is mounted on an automobile and
A motor control device that executes the magnetic force change control when the automobile is moving. In the motor control device according to claim 1 or 2.
A motor control device that executes the magnetic force change control when the rotation of the rotor is less than a predetermined rotation speed set in the control device, and does not execute the magnetic force change control when the rotation speed is equal to or higher than the predetermined rotation speed. In the motor control device according to any one of claims 1 to 3.
The plurality of coils are composed of a plurality of coil groups having different phases of flowing currents.
A motor control device in which the control device collectively changes the magnetic forces of all the magnetic poles by executing the magnetic force change control using a plurality of the coil groups. In the motor control device according to any one of claims 1 to 4.
A motor control device in which the control device changes the magnetic force of the magnetic pole by executing the magnetic force change control a plurality of times with respect to the same magnetic pole. In the motor control device according to claim 2,
A motor control device in which the control device drives the motor and executes the magnetic force change control while outputting the rotational power to the wheels of the automobile. In the motor control device according to claim 6,
A battery that constitutes a power source for the motor and energizes the coil with the magnetization current is further provided.
A motor control device that limits the execution of the magnetic force change control when the voltage of the battery is less than a predetermined lower limit value. In the motor control device according to claim 7,
The car has an engine
Based on the operation of the accelerator, the motor and the engine are configured to cooperate to drive the automobile.
A motor control device in which the rated voltage of the battery is 50 V or less.

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