JP7363553B2 - motor control device - Google Patents

Description

The disclosed technology relates to a motor control device.

In recent years, motors have been increasingly used in electric vehicles, hybrid vehicles, and the like. 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-voltage battery with a rated voltage of several hundred volts that can be charged by connecting to a charging stand or household power source as a power source for the drive motor.

Regarding the technology disclosed, Patent Document 2 discloses a motor for use in washing machines that can increase and demagnetize the magnetic force of a magnet.

In a washing machine, a high-torque, low-rotation motor output is required during the washing and rinsing processes, and a low-torque, high-rotation motor output is required during the dehydration process. Therefore, the washing machine is equipped with a transmission, and the transmission changes the output of the motor between two stages in accordance with these two processes. The washing machine of Patent Document 2 further changes the output characteristics of the motor by increasing or demagnetizing the magnetic force of the magnet from the normal magnetic force for each motor output switched by the transmission, and changing the output characteristics of the motor according to the load. We are making it possible to optimize it.

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

As mentioned above, in a washing machine, the frequently required output of the motor is limited to two output ranges. Therefore, motor output can be optimized simply by switching to either one using the transmission and increasing or demagnetizing the magnet depending on the size of the load based on the normal magnetic force in each output range. .

However, drive motors installed in automobiles and the like are required to have extremely high output power that can be driven over a very wide range in both the load direction and rotational direction. Moreover, since it moves itself, it has no choice but to use a battery as its power source.

In order to realize a high-output drive motor under such constraints, it is conceivable to install a high-voltage battery as in the hybrid vehicle of Patent Document 1, or to install a large-sized 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 disclosed technology relates to a motor control device.

The motor control device has magnets installed so that a plurality of magnetic poles are lined up in the circumferential direction, a rotor that outputs rotational power, and a plurality of coils that face the magnets with a gap in between and arranged in the circumferential direction. a motor having a stator installed in the motor; a drive current control unit that controls a drive current flowing through the coil to change the torque generated in the rotor; and a drive current control unit that controls a magnetizing current flowing in the coil and A control device having a magnetizing current control section that changes the magnetic force generated in the coil.

The control device is configured such that the drive current control section rotates the rotor such that at least one of the magnetic poles and at least one of the coils face each other, and an axis of the magnetic pole and an axis of the coil are close to each other. and in a state where the alignment control is performed, the magnetizing current control section is configured to execute magnetic force change control that changes the magnetic force of the magnet by controlling the magnetizing current. ing.

That is, according to this motor control device, the control device includes a magnetization current control section that controls the magnetization current flowing through the coil and changes the magnetic force generated in the coil. The magnetizing current control section changes the magnetic force of the magnet by controlling the magnetizing current. That is, the magnetic force of the rotor magnet can be varied in magnitude.

Thereby, the magnetic force of the magnetic poles can be changed according to the load of the motor, so the power factor of the motor can be increased. If the power factor of a motor is increased, high output can be obtained with less electric power, which means that the motor can be made lighter and more compact, and can provide appropriate output over a wider 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 a magnet, it is necessary to make the magnetic pole for changing the magnetic force and a predetermined coil face each other, and to generate a strong magnetic field with the coil. At that time, if a bias occurs in the magnetic field applied to the magnetic poles, there is a risk that the magnetization distribution of the magnetic poles will become non-uniform.

That is, since the positional relationship between the magnetic poles and the coil changes from moment to moment as the rotor rotates, the magnetic field distribution formed when a strong magnetic field is generated in the coil also changes from moment to moment. Therefore, the timing of magnetization to generate a strong magnetic field in the coil deviates from the timing when the axis of the magnetic pole and the axis of the coil are close to each other and the bias of the magnetic field becomes small, and the magnetic distribution of the magnetic pole tends to become non-uniform. As a result, the motor cannot properly output rotational power, and the motor output decreases.

Therefore, in this motor control device, a magnetic pole that changes magnetic force and a coil that applies a strong magnetic force to the magnetic pole face each other, and these magnetic poles and coils are arranged so that the axis of the magnetic pole and the axis of the coil are close to each other. Positioning control is performed to align both positions. Then, with the magnetic poles and the coils aligned, magnetic force change control is executed to change the magnetic force.

By doing so, the magnetic poles to be controlled and the coil are held in the optimal position, so the deviation in the timing of magnetization is suppressed, and the magnetic field formed by the magnetizing current flowing through the coil to be controlled is It is applied in a well-balanced manner to the target magnetic pole. Therefore, the magnetic poles to be controlled can be magnetized substantially uniformly. As a result, the motor can stably output appropriate rotational power, so the motor output can be made sufficiently high.

The motor control device may also be installed in an automobile, and the positioning control and the magnetic force change control may be executed when the automobile is stopped.

When a car is moving, the motor constantly swings and its position changes constantly. Therefore, if the magnetic force is changed in this state, the magnetic field will be greatly disturbed and the magnetization distribution of the magnetic poles will likely become even more non-uniform. On the other hand, when the car is stopped, the vibration and posture of the motor are relatively stable, so the accuracy of alignment between the magnetic poles and the coils is improved. Therefore, since the uniformity of the magnetization distribution of the magnetic poles is increased, the motor output can be made more stable and high.

Moreover, 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 this purpose, it is necessary to flow a large magnetizing current in the coil. Therefore, the magnetic force change control has a problem in that it consumes a large amount of electric power.

When the vehicle is stopped, the power source cannot be charged unless it generates electricity or uses an external power source. On the other hand, with this motor control device, the magnetic force can be changed in the optimal state by positioning, so the magnetic force can be changed appropriately with a single magnetic force change control using the necessary and minimum size magnetizing current. I can do it. Therefore, power consumption can be minimized.

In the motor control device, the plurality of coils are configured of a plurality of coil groups having different phases of flowing currents, and the control device is configured to select one of the plurality of magnetic poles from among the plurality of magnetic poles at the start of the alignment control. By performing the alignment control on the coil group located closest to the controlled magnetic pole that is the target of magnetic force change control, and then controlling the magnetizing current flowing through the coil group, The magnetic force change control may be performed on the magnetic pole to be controlled.

In other words, according to this motor control device, the plurality of coils are composed of a plurality of coil groups in which the phases of flowing currents are different. The magnetic force can be changed using the coil. Therefore, the number of times magnetic force change control is executed can be reduced.

Furthermore, at the time when changing the magnetic force is started, the positions of the magnetic poles that are subject to magnetic force change control (controlled magnetic poles) vary and are not constant. In contrast, in this motor control device, at the start of positioning control, positioning control is executed for the coil group located closest to the controlled magnetic pole among the plurality of magnetic poles. Therefore, since alignment control can be performed in the shortest time, the magnetic force can be changed in a short time.

The motor control device may also be configured such that the control device disengages a clutch interposed between a wheel of the automobile and the motor before executing the positioning control.

That is, the motor is connected to the wheels via the clutch. By engaging and disengaging the clutch, the output of the motor's rotational power to the wheels is adjusted. In this motor control device, the clutch is disengaged before positioning control is performed. By doing so, when the positioning control and the magnetic force change control are executed, the motor becomes independent, that is, the rotor rotates freely. As a result, the accuracy of positioning control and magnetic force change control is improved, so that the motor output can be sufficiently increased.

The motor control device also controls engagement of the clutch when execution of the magnetic force change control is started for any of the magnetic poles until execution of the magnetic force change control is finished for all the magnetic poles. It may be prohibited.

If the clutch is engaged after magnetic force change control has started but before the execution of magnetic force change control has finished for all magnetic poles, external force will be applied to the rotor, making positioning control unstable and preventing high-precision control. Magnetic force change control cannot be performed. Furthermore, if the magnetic force change control is interrupted and the motor is driven in that state, magnetic poles with different magnetic forces will coexist, and the motor will not function properly.

On the other hand, according to this motor control device, the clutch is not engaged until execution of the magnetic force change control is completed for all magnetic poles, so that the magnetic force can be stably changed for all magnetic poles. Then, when the clutch can be engaged, the magnetic forces of all the magnetic poles have been appropriately changed, so the motor functions properly.

The motor control device further includes a battery that constitutes a power source for the motor and that supplies the driving current and the magnetizing current to the coil, and when the voltage of the battery is less than a predetermined lower limit value, the magnetic force is reduced. It is also possible to limit the execution of change control.

That is, in this motor control device, a battery is used as a power source for the motor, and the magnetizing current used to change the magnetic force is also supplied from the battery. As mentioned above, in order to change the magnetic force of the magnet, it is necessary to flow a large magnetizing current through the coil. Therefore, if magnetic force change control is performed, there is a risk that the battery will be rapidly consumed and a voltage abnormality will occur.

On the other hand, according to this motor control device, when the voltage of the battery is less than the predetermined lower limit value, execution of the magnetic force change control is restricted, so it is possible to suppress the occurrence of voltage abnormality.

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

That is, this motor control device is installed in 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 mentioned above, it is equipped with a motor control device that can sufficiently increase the motor output, and these are effectively combined to avoid increasing the size and weight of 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.

1 is a schematic diagram showing the main configuration of an automobile to which the disclosed technology is applied. FIG. 2 is a schematic cross-sectional view showing the configuration of a motor. FIG. 2 is a block diagram showing an MCU and main input/output devices related thereto. FIG. 2 is a diagram showing a simplified configuration of a motor control device. 3 is a flowchart showing an example of motor control performed by the MCU. FIG. 3 is a diagram for explaining static magnetic force change control. FIG. 3 is a diagram for explaining dynamic magnetic force change control. FIG. 3 is a diagram for explaining dynamic magnetic force change control. It is a flow chart which shows an example of main processing of magnetic force change control. 3 is a flowchart illustrating an example of 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. 7 is a flowchart illustrating an example of magnetization execution restriction control.

Hereinafter, embodiments of the disclosed technology will be described in detail based on the drawings. However, the following description is essentially just an example, and does not limit the present invention, its applications, or its uses.

<Automobile>
FIG. 1 shows a four-wheeled automobile 1 to which the disclosed technology is applied. This car 1 is a hybrid car. An engine 2 and a motor 3 are installed as a drive source of an automobile 1. These work together to rotationally drive two wheels (drive wheels 4R) located symmetrically among the four wheels 4F, 4F, 4R, and 4R. Thereby, the car 1 moves (runs).

In the case of this automobile 1, the engine 2 is arranged at the front side of the vehicle body, and the drive wheels 4R are arranged at the rear side of the vehicle body. That is, this automobile 1 is a so-called FR vehicle. Furthermore, in the case of this automobile 1, the engine 2 is the main driving source rather than the motor 3, and the motor 3 is used to assist the driving 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 an engine 2 and a motor 3, the automobile 1 includes 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 travels by the action of a complex (drive system) of these devices.

The automobile 1 also includes 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 general control unit (GCU) as control system devices. )24 etc. are provided.

An engine rotation sensor 50, a motor rotation sensor 51, a current sensor 52, a magnetic force sensor 53, an accelerator sensor 54, etc. are also installed in the automobile 1 along with the control system devices.

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

In this automobile 1, the engine 2 is disposed approximately at the center in the width direction of the vehicle, with the output shaft for outputting rotational power facing in the longitudinal direction of the vehicle body. The automobile 1 is equipped with various devices and mechanisms associated with the engine 2, such as an intake system, an exhaust system, and a fuel supply system, but illustrations and explanations of these will be omitted.

(motor)
The motor 3 is 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 roughly includes a motor case 31, a shaft 32, a rotor 33, a stator 34, and the like.

The motor case 31 is a container having a cylindrical space inside thereof whose front end face and rear end face are sealed, and is fixed to the body of the automobile 1. The rotor 33 and 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 respectively protruding from the motor case 31 .

The first clutch 5 is installed to be interposed between the front end of the shaft 32 and the output shaft of the engine 2. The first clutch 5 has two states: a state in which the output shaft and the shaft 32 are connected (a state in which the first clutch 5 is connected, a connected state) and a state in which the output shaft and the shaft 32 are separated (a state in which the first clutch 5 is disengaged). It is configured so that it can be switched between the closed state and the released state.

The second clutch 7 is installed to be interposed between the rear end of the shaft 32 and the input shaft of the transmission 8. The second clutch 7 has a state in which the shaft 32 and the input shaft of the transmission 8 are connected (a state in which the second clutch 7 is connected, a connected state) and a state in which the shaft 32 and the input shaft of the transmission 8 are separated. (a state in which the second clutch 7 is disengaged, a released state). Note that each of the first clutch 5 and the second clutch 7 is configured such that the magnitude of the transmitted power can be adjusted in a state between a connected state and a released state (partially connected state).

(rotor)
The rotor 33 is a cylindrical member formed by laminating a plurality of metal plates having an axial 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 around the entire circumference of the rotor 33. The magnet 35 is configured such that a plurality (eight in this figure) of magnetic poles 35a consisting of an S pole and an N pole are arranged alternately at equal intervals in the circumferential direction. The magnet 35 may be composed of a single cylindrical magnet having a plurality of magnetic poles 35a, or may be composed of a plurality of arc-shaped magnets forming each magnetic pole 35a (in the illustrated example, a plurality of arc-shaped magnets are used). (consisting of magnets).

In this motor 3, the magnet 35 is further configured to be able to vary the magnitude of magnetic force (variable magnetic force magnet). Usually, this type of motor 3 uses a magnet (permanent magnet) that has a large coercive force (coercive force) and can maintain magnetic force for a long period of time. In this motor 3, a permanent magnet with 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 also vary. The type and material of the magnet 35 can be selected according to specifications and are not particularly limited.

In this automobile 1, the 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 electric wires around the stator core 34a.

The stator core 34a is provided with a plurality of teeth 34b that extend radially inward, and by winding electric wires in a predetermined order in the spaces (slots) formed between these teeth 34b, a plurality of teeth 34b (this figure In the example, 12 coils 36 are formed (so-called concentrated winding). These coils 36 constitute a three-phase coil group consisting of U-phase, V-phase, and W-phase, which flow currents in different phases. The coils of each phase are arranged in order in the circumferential direction.

In addition, in this embodiment, although the motor 3 of 8 poles and 12 slots was illustrated, the structure 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 with 2 N times as many magnetic poles 35a and 3 N times as many slots (N is an integer).

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

Therefore, unlike the hybrid vehicle of Patent Document 1 mentioned above, since the voltage is not high, the battery 10 itself can be made lightweight and compact. Furthermore, since advanced electric shock countermeasures are not required, insulating members and the like can be simplified, resulting in a lighter and more compact structure. Therefore, since the vehicle weight of the automobile 1 can be suppressed, fuel efficiency and power consumption can be suppressed.

Battery 10 supplies DC power to inverter 6. The inverter 6 converts the DC power into three-phase AC power and energizes the motor 3. As a result, electromagnetic force is generated in each coil 36. The rotor 33 is rotationally driven by the attractive force and 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 this 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 speed change mechanisms such as a plurality of planetary gear mechanisms, clutches, and brakes are incorporated between the input shaft and the output shaft.

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

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

[Control system equipment]
The above-mentioned units ECU 20, MCU 21, TCU 22, BCU 23, and GCU 24 are installed in the automobile 1 in order to control its driving according to the driver's operations. Each of these units is composed of hardware such as a CPU, memory, and interface, and software such as a database and 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 operations of the first clutch 5, the second clutch 7, and the transmission 8. This is a unit that mainly controls the operation of the BCU 23 and the brake 14. The GCU 24 is a host unit that is electrically connected to these ECU 20, MCU 21, TCU 22, and BCU 23 and controls them comprehensively. The MCU 21 constitutes the main body of a "control device." Units such as the GCU 24 constitute a "control device" by cooperating 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 the detected rotation speed to the ECU 20. The motor rotation sensor 51 is attached to the motor 3, detects the rotational speed and rotational position of the rotor 33, and outputs the detected rotational speed and rotational position 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 it to the MCU 21.

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

The automobile 1 travels by each unit working together to control the drive system based on detection value signals input from these sensors. For example, when the automobile 1 is driven by 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.

The TCU 22 then controls the first clutch 5 and the second clutch 7 to be in a connected state. When braking the automobile 1, the BCU 23 controls each brake 14. During braking due to regeneration, the TCU 22 controls the first clutch 5 to be in a released state or a partially connected state, and controls the second clutch 7 to be in a connected state. Then, the MCU 21 controls the motor 3 to generate electricity and the electric power to be recovered by the battery 10.

<Motor control device>
The MCU 21 controls the vehicle 1 to run using the rotational power of the motor 3, either with the motor 3 outputting power alone or with assisting the output of the engine 2 as needed.

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

FIG. 3 shows the MCU 21 and the main input/output devices related thereto. The MCU 21 is provided with a drive current control section 21a and a magnetization current control section 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. This causes the motor 3 to output the required amount of rotational power.

On the other hand, the magnetizing current control section 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 magnetizing 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 drive current.

The power factor is the ratio of active power (actually consumed power) to apparent power (power supplied to the motor 3). When the power factor is low, it is necessary to apply a large current 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. Furthermore, if the power factor increases, the power generated 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 substantially match the magnetic force of the permanent magnet (if the electromagnetic force and the magnetic force substantially match, the power factor will be approximately 1). On the other hand, in the case of a normal permanent magnet motor, the magnetic force of the permanent magnet does not change, so in the most frequently used area where the motor outputs, a permanent magnet with a magnetic force that has a power factor of approximately 1 is used. There is.

That is, the type, material, structure, etc. of the permanent magnet are designed according to specifications, and in the initial state when 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 motor output is required is relatively limited, so even such motor characteristics do not pose a big problem. However, when driving the automobile 1, highly frequent output is required over a very wide range. Therefore, with such motor characteristics, there are problems such as a need for a higher battery voltage and a larger motor.

In contrast, this motor control device uses a magnet 35 whose magnetic force can be changed, and the MCU 21 is provided with a magnetizing current control section 21b, so that the power factor can be improved and such problems can be resolved. It has become.

That is, when the load on the motor 3 changes, the magnetic force of the magnet 35 is changed in accordance with the load. For example, at a medium load, the magnetic force of the magnet 35 is increased (magnetization) compared to the magnetic force at a low load so that the power factor becomes approximately 1. At low loads, the magnetic force of the magnet 35 is reduced (demagnetized) compared to the magnetic force at medium loads 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 rotation speed of the motor 3. The output range is divided into multiple areas. In each of these regions, the magnetizing 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 (magnetized regions) in which the magnetic force of the magnet 35 is different.

In addition, 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 its initial state. In this way, even under high loads, the power factor can be increased to approximately 1. Therefore, in this case, the motor 3 can be driven efficiently even under high load, so even if the motor 3 is lightweight and compact, insufficient output can be suppressed, and stable running can be achieved.

At medium or low loads, the electromagnetic force decreases depending on the load, but with the magnet 35, the power factor can be made approximately 1 by demagnetizing it in accordance with the electromagnetic force. Therefore, in this case, the power factor can be increased over substantially the entire output range of the motor, and the motor 3 can be driven efficiently.

In this way, this motor control device is configured so that 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 in both the state where the car 1 is stopped and the state where the car 1 is running. It has been devised so that it can be executed at a high level. Details of these will be described later.

<Control of motor by motor control device>
FIG. 4 shows a simplified system diagram of the motor control device. FIG. 5 shows an example of control of the motor 3 performed by the MCU 21. A specific flow of control of the motor 3 will be explained 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 excitation current command Id ^* corresponding to the magnetizing current.

When the vehicle 1 is ready to run, the MCU 21 constantly receives detected values from the current sensor 52, motor rotation sensor 51, and magnetic force sensor 53 (step S1). Similarly, the ECU 20 also constantly receives detected values from the accelerator sensor 54 and the engine rotation sensor 50.

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

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 value Idq ^* ) is calculated (step S3). Furthermore, the MCU 21 (magnetization current control unit 21b) calculates a command (magnetization state command value Φ ^* ) that outputs the optimum value of magnetic force corresponding to the magnetization region based on the torque command value T ^* and the rotation speed of the motor 3. Processing is executed (step S4). Then, the magnetizing current control unit 21b issues a command (magnetic force current command value Idq ^* ) to output 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 magnetic force current command value Idq ^* (step S6). For example, if outputting the requested torque results in a transition to a different magnetization region, it is determined that the magnetic force of the magnet 35 needs to be changed. Even if the requested torque is output, if the magnets are located in the same magnetized region, it is determined that the magnetic force of the magnet 35 does not need to be changed.

If the MCU 21 determines that it is not necessary to change the magnetic force of the magnet 35, the MCU 21 determines whether the output torque is greater than the torque T1 at 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 normal vector control.

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

By outputting the switching command value to the inverter 6 through the driver circuit, a plurality of switching elements are controlled on and off inside the inverter 6. As a result, a predetermined three-phase alternating current (drive current) is applied to each coil group, the motor 3 rotates, and the requested 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), magnetic force change control is executed by the magnetizing current control section 21b (step S11).

Furthermore, even if the MCU 21 determines that it is not necessary to change the magnetic force of the magnet 35, if the output torque is determined to be less than or equal to the torque T1 at which the motor 3 runs idle (No in step S7), the magnetizing current control unit 21b executes magnetic force change control (step S11).

When the motor 3 is running 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 to the initial state magnetic force (load upper limit magnetic force). will be changed to In the case of the automobile 1, for example, there are cases where the accelerator pedal 15 is depressed all at once from an idling state or a stopped state, resulting in sudden acceleration. 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 mentioned above, this motor 3 uses a magnet 35 whose magnetic force can be changed. Then, the MCU 21 (magnetizing current control unit 21b) executes control to change the magnetic force of the magnet 35 (magnetic force change control). In order to change the magnetic force of the magnet 35, a strong magnetic force (magnetization magnetic force) must be applied.

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

In the magnetic force change control, the magnetic pole 35a (control target magnetic pole) to be subjected to the magnetic force change control and the coil 36 (control target coil) to be subjected to the magnetic force change control are arranged to face each other. Then, among the current flowing through the controlled coil, a current component (magnetizing current) that causes the controlled coil to generate a magnetic force in the radial direction is adjusted.

For example, when increasing magnetization, a large pulsed magnetizing current is passed through the controlled coil so that a strong magnetic flux is generated in the same direction as the magnetic flux of the controlled magnetic pole. When demagnetizing, a large pulsed magnetizing current is passed through the controlled coil so that a strong magnetic flux is generated in the opposite direction to the magnetic flux of the controlled magnetic pole.

At this time, if a bias occurs in the magnetic field applied to the magnetic pole to be controlled, the magnetization of each part of the magnetic pole 35a may vary, and the magnetization distribution of the magnetic pole 35a may become non-uniform.

That is, when the rotor 33 rotates, the positional relationship between the controlled magnetic poles and the controlled 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 coil to be controlled also changes from moment to 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 become non-uniform. As a result, the motor 3 is unable to output rotational power appropriately, and the motor output decreases.

In the case of the automobile 1, unlike household appliances that do not move, it is not always possible to perform magnetic force change control with the motor in a stable state. The motor swings when the vehicle is running, and even when the vehicle is stopped the motor swings when the engine is running or the passenger moves. Furthermore, the attitude of the motor is not constant. If the magnetic force change control is executed in a state where the motor is oscillating or has an unstable posture, the magnetic field applied to the magnetic pole to be controlled is likely to be disturbed, resulting in a decrease in the accuracy of the magnetic force change. 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, this motor control device is devised so that the magnetic force change control can be executed with high precision both when the vehicle 1 is stopped and when the vehicle 1 is running.

Specifically, the MCU 21 performs magnetic force change control (static magnetic force change control) suitable for performing with the motor 3 separated from the drive system, and magnetic force change control suitable for performing with the motor 3 separated from the drive system. The magnetic force change control (dynamic magnetic force change control) suitable for this is configured to be executable. Then, the MCU 21 selects and executes any one of these controls.

Static magnetic force change control is mainly performed while the vehicle 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, in a case where the automobile 1 is running by inertia, the process can be executed even when the automobile 1 is not stopped.

The dynamic magnetic force change control is mainly performed while the vehicle 1 is running. Dynamic magnetic force change control can be executed even when the automobile 1 is stopped. However, as will be described later, in terms of accuracy of magnetic force change, power consumption of battery 10, etc., it is preferable to perform static magnetic force change control when vehicle 1 is stopped.

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

Before 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 from both the engine 2 and the transmission 8. Thereby, the rotor 33 and the shaft 32 are in a free state, that is, a freely rotatable state. As a result, alignment between the controlled magnetic pole and the controlled coil becomes easy, and the accuracy of alignment control can be improved.

In the positioning control, the rotor 33 is rotated so that the magnetic pole to be controlled and the coil to be controlled face each other, and the axis of the magnetic pole to be controlled and the axis of the coil to be controlled are close to each other. Note that the number of magnetic poles to be controlled and coils to be controlled that are simultaneously controlled for positioning may vary depending on the configuration of the motor 3.

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

For example, assume that the rotor 33 is located at the position shown in the upper diagram of FIG. 6 when static magnetic force change control is started. The rotor 33 may be stationary or rotating. When the coil 36 of the U-phase coil group is the coil to be controlled and the N-pole magnetic pole 35a is the magnetic pole to be controlled, the MCU 21 (drive current control unit 21a) receives a signal input from the motor rotation sensor 51 (rotor 33 rotation position information), the rotor 33 is rotated by a predetermined angle. By doing so, 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, as shown in the middle diagram of FIG. Match.

Preferably, the positions are adjusted so that both axes Jc and Jp substantially coincide with each other. As a result, it is possible to prevent a shift in the positional relationship between the controlled magnetic pole and the controlled coil, and to ensure optimal magnetization timing that can reduce the bias of the magnetic field applied to the controlled magnetic pole. At this time, if the motor 3 is separated from the drive system, stable alignment can be achieved and the influence of external causes such as vibration can be suppressed. Therefore, the accuracy of positioning control is improved.

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

For example, suppose that the rotor 33, which is not rotating, is at the position shown in the upper diagram of FIG. 6 at the start of the alignment control. In this case, when the N-pole magnetic pole 35a is the controlled magnetic pole, the axis Jc of the coil 36 of the U-phase coil group is located closest to the axis Jp of the controlled magnetic pole. Therefore, in this case, it is preferable to perform positioning control by rotating the rotor 33 as shown in the figure.

In the same case, when the S-pole magnetic pole 35a is the controlled magnetic pole, the axis Jc of the coil 36 of the V-phase coil group is located closest to the axis Jp of the controlled magnetic pole. Therefore, in this case, it is preferable to execute positioning control by rotating the rotor 33 clockwise.

Then, with the magnetic poles to be controlled and the coils to be controlled aligned in this way, the MCU 21 (magnetizing current control unit 21b) sends a pulse-like pulse with a predetermined intensity to the U-phase coil group, which is the coil to be controlled. Control the flow of magnetizing current. Since the axis Jp of the magnetic pole to be controlled and the axis Jc of the coil to be controlled are close to each other (substantially coincident), the magnetic field formed by the magnetization current flowing through the coil to be controlled is schematically shown by the broken line in the middle diagram of FIG. As shown in the figure, the voltage is applied in a well-balanced manner to the magnetic poles to be controlled. Therefore, the magnetic pole to be controlled can be magnetized substantially uniformly.

In the case of the illustrated motor, the two magnetic poles (N poles) 35a, 35a are simultaneously aligned with the U-phase coil group, and magnetic force change control is executed. In the case of the illustrated motor, 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, 35a become new magnetic poles to be controlled.

The MCU 21 (drive current control unit 21a) further rotates the rotor 33 by a predetermined angle based on a signal input from the motor rotation sensor 51. By doing so, as shown in the lower diagram of FIG. In the illustrated example, both the magnetic pole to be controlled and the coil to be controlled are aligned so that the axis Jc of the W-phase or V-phase coil 36) approaches (substantially coincides with).

Then, the MCU 21 (magnetizing current control unit 21b) executes magnetic force change control using the W-phase coil 36 in the illustrated example, and also changes the magnetic force of these new control target magnetic poles. If the number of magnetic poles is even larger, the MCU 21 executes alignment control and magnetic force change control for all magnetic poles 35a, and repeats this series of processes until the magnetic force of all magnetic poles 35a is changed. Execute.

In this series of processes, when execution of magnetic force change control is started for any of the magnetic poles 35a, engagement of the clutch is prohibited until execution of magnetic force change control for all 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 does not change the magnetic force of all the magnetic poles 35a after starting to change the magnetic force of the magnetic poles 35a. Priority is given to the processing until it is completed.

If the first clutch 5 and/or the second clutch 7 are connected before the magnetic force change control is completed for all magnetic poles 35a, an external force will be applied to the rotor 33, making the positioning control unstable. , it is not possible to perform highly accurate magnetic force change control. Furthermore, if the magnetic force change control is interrupted and the motor 3 is driven in that state, the motor 3 will not function properly because magnetic poles 35a with different magnetic forces will coexist. Therefore, there is a possibility that the motor 3 cannot output the rotational power required by the MCU 21.

On the other hand, if the change in the magnetic force of all the magnetic poles 35a is completed, the motor 3 will function 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, its power source is limited to the battery 10, unlike home appliances that can always receive a constant supply of electric power from a commercial power source. Moreover, the battery 10 of this automobile 1 is a low voltage battery. Since magnetic force change control requires a large current, in the case of the automobile 1, there is a problem in that the battery 10 is rapidly consumed.

When the automobile 1 is stopped, regeneration using running is not possible, so the battery 10 cannot be charged unless the engine 2 is used to generate electricity or an external power source is used. On the other hand, static magnetic force change control allows the magnetic force to be changed in an optimal state for each magnetic pole 35a, so the magnetic force can be changed with one magnetic force change control using the necessary and minimum magnitude of magnetizing current. Changes can be made appropriately. Therefore, power consumption can be minimized, and rapid depletion 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 a predetermined coil 36 passes through the magnetic pole 35a while the rotor 33 is rotating. Specifically, when the rotor 33 is rotating and the controlled coil passes from one end to the other end of the controlled magnetic pole in the circumferential direction, the MCU 21 (magnetizing current control unit 21b) executes magnetic force change control.

Since the dynamic magnetic force change control is performed while the rotor 33 is rotating, it can be performed even when the vehicle 1 is running. Therefore, compared to static magnetic force change control, there is an advantage that there are fewer restrictions on execution. For example, if the car 1 is running with only the engine 2 driving, if the car 1 is running with the motor 3 assisting the driving of the engine 2, if the car 1 is running with the drive of the motor 3 only. Dynamic magnetic force change control can be executed in both cases. Further, even when the automobile 1 is stopped, the process 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 normal control of the motor 3 can be performed by separating the motor 3 from the drive system. There are advantages that do not require major restrictions. Therefore, complication of control can be avoided.

Dynamic magnetic force change control will be described with reference to FIG. 7. For example, assume that when dynamic magnetic force change control is started, the rotor 33 is rotating counterclockwise, as shown in the upper diagram of FIG. Then, assuming that the coil 36 of the U-phase coil group is the coil to be controlled and the magnetic pole 35a (N pole) is the magnetic pole to be controlled, the MCU 21 (magnetizing current control unit 21b) receives the signal input from the motor rotation sensor 51 (rotor 33), the time required for the controlled magnetic pole to pass through one controlled object coil (magnetization time) is calculated.

Then, as shown in the middle diagram of FIG. 7, the rotor 33 rotates, and one end of the controlled magnetic pole in the circumferential direction (the end located on the advancing side in the rotational direction, the advance side end Epf) , a position that coincides in the radial direction with one end in the circumferential direction (end located on the opposite advancing side in the rotation direction, retard side end Ecr) of the controlled coil (substantially the tip of the tooth 34b) When the current is reached, the MCU 21 (magnetizing current control unit 21b) controls the U-phase coil group, which is the coil to be controlled, so that the magnetizing current starts to flow at a predetermined intensity, and starts time measurement.

Then, when the magnetization time has elapsed, the rotor 33 rotates further, as shown in the lower diagram of FIG. It reaches a position that coincides with the other end (advanced angle end Ecf) of the coil in the circumferential direction in the radial direction. In other words, the controlled magnetic pole passes through the controlled coil.

During this time, the MCU 21 (magnetizing current control unit 21b) controls the magnetizing current of a predetermined strength to continue flowing through the controlled coil, and ends the control when the controlled magnetic pole passes through the controlled coil. .

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

Note that even while applying the magnetizing current to the coils 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, rotational power can be output from the motor 3 even during execution of dynamic magnetic force change control. However, during that time, the rotational power output from the motor 3 also changes as the magnetic force of the controlled magnetic pole changes.

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, calculation of the magnetization time becomes simple. Disturbances in the magnetic field applied to the magnetic poles to be controlled can also be further suppressed. Therefore, the accuracy of magnetic force change control is further improved.

Furthermore, it is preferable that the dynamic magnetic force change control be executed when the rotational 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 number of rotations, and not executed when the rotation number of the rotor 33 is greater than or equal to a predetermined number of rotations. As the rotation speed of the rotor 33 increases, the magnetization time becomes shorter, so there is a possibility that the required magnetic force cannot be changed by one magnetization. Furthermore, the magnetization distribution of the magnetic pole 35a tends to become non-uniform. On the other hand, the lower the rotation speed of the rotor 33, the longer the magnetization time becomes, so the amount of magnetic force that can be changed by one magnetic force change control increases, and the magnetization distribution of the magnetic poles 35a tends to become uniform. Therefore, the accuracy of magnetic force change control is improved.

The predetermined rotation speed serving as a criterion may be appropriately set according to the specifications of the motor 3 and the like. For example, the range of the number of rotations that can be output by the motor 3 may be divided into low, medium and high parts, and any number of rotations in the middle range may be set as the predetermined number of rotations. Further, an arbitrary number of rotations in the low range may be set as the predetermined number of rotations.

In the case of the illustrated motor 3, the two magnetic poles (N poles) 35a, 35a are simultaneously aligned with the U-phase coil group, and magnetic force change control is executed. In the case of the illustrated motor 3, 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 magnetic poles to be controlled.

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

The upper diagram in FIG. 8 shows a state where magnetic force change control is being executed on the magnetic pole 35a (N pole). While the controlled object coil (U phase) is passing through the controlled object magnetic pole, the S pole magnetic pole 35a starts passing through the coil 36 of the W phase coil group. That is, the coil 36 of the W-phase coil group can be used as the controlled coil, and the magnetic pole 35a (S pole) can be used as the controlled magnetic pole.

Therefore, the MCU 21 (magnetizing current control unit 21b) is configured such that the advance side end Epf of the controlled magnetic pole (S pole) is radially equal to the retard side end Ecr of the controlled coil (W phase coil 36). When the position coincides with , the magnetizing 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 time measurement is started.

Then, after the magnetization time has elapsed, as shown in the lower diagram of FIG. The MCU 21 (magnetizing current control unit 21b) controls so that the magnetizing current of a predetermined strength continues to flow through the controlled coil (W-phase coil 36) until reaching a position that coincides with Ecf in the radial direction. .

In this way, by performing 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 force 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 also be shared, calculation processing can also be simplified.

In the case of dynamic magnetic force change control, the magnetization time for applying the magnetization magnetic force to the controlled magnetic pole changes depending on the rotation speed of the rotor 33. As described above, when the rotational 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 (magnetizing current control unit 21b) performs dynamic magnetic force change control multiple times on the same magnetic pole to be controlled.

That is, the MCU 21 (magnetizing current control unit 21b) determines whether the magnetic force of the magnet 35 has reached the required magnetic force (optimum magnetic force value) based on the signal input from the magnetic force sensor 53. Then, the MCU 21 (magnetizing current control unit 21b) performs dynamic magnetic force change control multiple times on 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 variations in the rotational 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, it is affected by harmonics, so the magnetization distribution tends to become non-uniform. On the other hand, if magnetization is performed multiple times, the influence of harmonics can be reduced, and the uniformity of the magnetization distribution of the magnetic pole 35a can also be improved.

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

Since dynamic magnetic force change control has lower magnetization efficiency than static magnetic force change control, power consumption is greater than static magnetic force change control. Therefore, the power of the battery 10 suddenly decreases below the limit, which may cause a power problem. Therefore, it is preferable to perform static magnetic force change control when the vehicle 1 is stopped.

On the other hand, in the case of dynamic magnetic force change control, it can be executed while the vehicle 1 is running or while the engine 2 is driving, so the battery 10 can be charged by the power of the engine 2 or regeneration during braking. Therefore, even if the power consumption is large, the power of the battery 10 can be replenished by charging, thereby preventing the power of the battery 10 from decreasing.

[Specific example of magnetic force change control]
FIG. 9 illustrates the main processing of magnetic force change control. The MCU 21 determines whether the automobile 1 is stopped via the GCU 24 (step S20). In this example, the MCU 21 executes static magnetic force change control when the car 1 is stopped, and executes dynamic magnetic force change control when the car 1 is running.

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

As shown in FIG. 10, when the MCU 21 starts positioning control, the GCU 24 executes 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. The motor 3 is thereby separated from the drive system and becomes independent.

The MCU 21 then determines the coil to be controlled (step S32). Specifically, at the start of alignment control, the coil 36 whose axis Jc is closest to the axis Jp of the magnetic pole to be controlled is selected as the coil to be controlled. Then, when the coil to be controlled is selected, the MCU 21 generates a current command value (positioning current command Iuvw ^* ) is calculated (step S33).

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

When the position of the rotor 33 is determined to be appropriate, the MCU 21 is enabled to perform static magnetic force change control. After that, the MCU 21 determines whether or not the static magnetic force change control has ended (step S36), and performs control so that the aligned state is maintained until the static magnetic force change control ends ( No in step S36).

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

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

As shown in FIG. 11, when static magnetic force change control is started, the MCU 21 executes magnetizing current control (step S40). Specifically, the MCU 21 applies a predetermined pulsed magnetizing current to the coil to be controlled through the inverter 6, depending on either the amount of magnetization or the amount of demagnetization required for the magnetic pole to be controlled. As a result, when the magnetic force of the controlled magnetic pole reaches the determined value (optimum magnetic force value), the static magnetic force change control ends. Note that whether or not the magnetic force of the controlled magnetic pole has reached the determined 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 change of the magnetic force of all the magnetic poles 35a is completed (step S24).

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

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 specifies the rotational position of the rotor 33 based on the signal input from the motor rotation sensor 51, and determines whether the advance side end Epf of the controlled magnetic pole is equal to the retard side end Ecr of the controlled coil. Control (standby control) is executed to wait until a position matching the direction is reached (step S51). As for the magnetic pole to be controlled and the coil to be controlled, it is preferable to select the magnetic pole 35a and coil that are located closest in the rotational direction when the dynamic magnetic force change control is started.

When the advanced end Epf of the controlled magnetic pole reaches a position where it radially coincides with the retarded end Ecr of the controlled coil, the MCU 21 directs the coil group constituting the controlled coil to The magnetizing current is controlled to start flowing at a predetermined intensity, and time measurement is started (step S52). The application of the magnetizing current is then continued until the magnetization time has elapsed.

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 force of all the magnetic poles 35a at once.

By applying the magnetizing current, the magnetic force of the controlled magnetic pole changes. Accordingly, the torque generated in the rotor 33 also changes. As a result, the rotational power output from the motor 3 also changes, which may disrupt the running of the automobile 1.

On the other hand, in the case of this automobile 1, the engine 2, the brake 14, and/or the clutches 5, 7 are used to adjust the torque (torque adjustment control) so as to suppress the influence of such torque changes. ) is executed (step S53). For example, when demagnetizing the magnetic pole 35a, since the torque of the rotor 33 changes slightly, control is executed to output rotational power from the engine 2 in accordance with the change. When magnetizing the magnetic pole 35a, the torque of the rotor 33 changes significantly, so control is executed to brake the rotational power with the brake 14 in accordance with the change. Then, together with or separately from these controls, each of the first clutch 5 and the second clutch 7 is brought into a partially engaged state to adjust the magnitude of the transmitted power, thereby reducing the influence of torque changes. It can be suppressed.

Then, when the magnetization time has elapsed and the controlled magnetic pole passes through the controlled coil, the application of the magnetizing current and the standby control are ended (step S54). Based on the signal input from the magnetic force sensor 53, the MCU 21 determines whether the magnetic force of the magnet 35 has reached the required magnetic force (optimum value of magnetic force) (step S55). Then, the MCU 21 repeatedly executes dynamic magnetic force change control until the magnetic force of the magnet 35 reaches the optimum magnetic force value (No in step S55).

Execution of such magnetic force change control requires a large current. Therefore, in the case of the automobile 1, there is a problem in that the battery 10 is rapidly consumed. In particular, in the case of a low-voltage battery, the voltage is low even in a fully charged state, so there is a risk that voltage abnormalities will occur frequently.

Therefore, this automobile 1 is configured so that 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 restriction control). Specifically, 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 are set in advance in the MCU 21.

Static magnetic force change control can magnetize the magnet 35 more efficiently than dynamic magnetic force change control, so power consumption can be reduced. Therefore, the first lower limit value V1 is higher than the second lower limit value V2 (V1>V2). Note that the values of the first lower limit value V1 and the second lower limit value V2 can be selected as appropriate depending on the specifications of the motor 3 and the details of the restrictions.

FIG. 13 shows an example of the magnetization execution restriction control. While driving the automobile 1, the MCU 21 always determines whether 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 that consumes a large amount of power can be executed without any problem, so that magnetization execution is limited. There is no control.

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

Furthermore, if the voltage of the battery 10 decreases, there is a risk that voltage abnormalities will occur frequently even with static magnetic force change control. Therefore, the MCU 21 also determines whether 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 static magnetic force change control is also restricted (step S63). For example, execution of static magnetic force change control is prohibited or the number of times it is executed is limited.

When the voltage of the battery 10 increases as it is charged, the restrictions on each magnetic force change control are lifted according to the degree of increase. Therefore, according to this motor control device, the occurrence of voltage abnormality can be suppressed, so that the automobile 1 can run stably.

Note that the motor control device according to the disclosed technology is not limited to the embodiments described above, and includes various other configurations.

For example, in the embodiment described above, the application to a hybrid vehicle has been described as an example, but the present invention may also be applied to an electric vehicle that runs only by a motor, or a two-wheeled vehicle such as a motorcycle or an electric bicycle. Note that the disclosed technology is applicable not only to such moving objects but also to non-moving objects.

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

1 Car 2 Engine 3 Motor 4 Wheel 4R Drive wheel 5 First clutch 6 Inverter 7 Second clutch 8 Transmission 10 Battery 20 Engine control unit (ECU)
21 Motor control unit (MCU)
21a Drive current control section 21b Magnetizing current control section 22 Transmission control unit (TCU)
23 Brake control unit (BCU)
24 General control unit (GCU)
33 Rotor 34 Stator 35 Magnet (variable magnetic force magnet)
35a magnetic pole 36 coil

Claims (6)

A rotor in which a plurality of magnets are installed so that a plurality of magnetic poles are arranged in a circumferential direction and outputs rotational power, and a plurality of coils that face the magnets across a gap and have different phases of flowing currents. a motor having a stator in which coils are arranged circumferentially;
a drive current control unit that controls a drive current flowing through the coil to change the torque generated in the rotor; and a magnetization current control unit that controls a magnetization current that flows through the coil to change the magnetic force generated in the coil. a control device having a section;
Equipped with
The control device includes:
The drive current control unit performs alignment control to rotate the rotor so that at least one of the magnetic poles and at least one of the coils face each other, and the axis of the magnetic pole and the axis of the coil are close to each other. and in a state where the positioning control is performed, the magnetizing current control unit is configured to execute magnetic force change control that changes the magnetic force of the magnet by controlling the magnetizing current,
At the start of the alignment control, performing the alignment control on the coil group that is located closest to the controlled magnetic pole that is the target of the magnetic force change control among the plurality of magnetic poles, Thereafter, the motor control device executes the magnetic force change control on the controlled magnetic pole by controlling the magnetizing current flowing through the coil group . The motor control device according to claim 1,
The motor control device is installed in an automobile,
A motor control device that performs the positioning control and the magnetic force change control when the automobile is stopped. A motor control device installed in a car,
A rotor in which a plurality of magnets are arranged so that a plurality of magnetic poles are arranged in a circumferential direction and outputs rotational power, and a stator in which a plurality of coils facing the magnets across a gap are arranged in a circumferential direction. a motor having
a drive current control unit that controls a drive current flowing through the coil to change the torque generated in the rotor; and a magnetization current control unit that controls a magnetization current that flows through the coil to change the magnetic force generated in the coil. a control device having a section;
Equipped with
The control device includes:
The drive current control unit performs alignment control to rotate the rotor so that at least one of the magnetic poles and at least one of the coils face each other, and the axis of the magnetic pole and the axis of the coil are close to each other. and in a state where the positioning control is performed, the magnetizing current control unit is configured to execute magnetic force change control that changes the magnetic force of the magnet by controlling the magnetizing current,
The alignment control and the magnetic force change control are executed while the automobile is stopped, and before the alignment control is executed, the control device is interposed between the wheels of the automobile and the motor. A motor control device that disengages the clutch . The motor control device according to claim 3,
A motor control device that prohibits engagement of the clutch when execution of the magnetic force change control is started for any of the magnetic poles until execution of the magnetic force change control is finished for all the magnetic poles. The motor control device according to claim 3 or 4,
further comprising a battery that constitutes a power source for the motor and causes the driving current and the magnetizing current to flow through the coil,
A motor control device that limits execution of the magnetic force change control when the voltage of the battery is less than a predetermined lower limit value. The motor control device according to claim 5,
the vehicle includes an engine;
The motor and the engine are configured to work together to drive the vehicle based on operation of an accelerator,
A motor control device in which the rated voltage of the battery is 50V or less.

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