JPH06217596A - Control device for winding switching permanent magnet motor - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent a shock when switching windings in a permanent magnet motor. [Configuration] Motors A and B are set to a differential gear 1
A double motor 12 connected by 0 is configured. When the rotation speed of the output shaft 24 of the double motor 12 shifts from the low speed rotation range to the high speed rotation range or from the high speed rotation range to the low speed rotation range, the ECU 30 controls the contactors 32A and 32B to wind the motors A and B. Switch lines. The winding switching timing of the motor A and the winding switching timing of the motor B are different. EC when switching windings
U30 controls the inverters 28A and 28B to control the output torque of the motor A or B for switching windings to zero. [Effect] Since the winding switching is performed in a state where the output torque is 0, no shock occurs due to the winding switching.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for controlling a winding-switching permanent magnet motor, that is, a controller for a winding-switching permanent magnet motor.

[0002]

2. Description of the Related Art When an AC motor is used as a running motor for an electric vehicle, a system for converting DC power supplied from a vehicle battery into AC power using an inverter and supplying the AC power to the running motor. The composition is adopted.
With such a system configuration, the output torque of the motor can be suitably controlled by controlling the switching of each switching element that constitutes the inverter.

Further, as a traveling motor, adoption of a permanent magnet motor is being considered for downsizing of the device. A permanent magnet motor is a motor in which one of a rotor and a stator is composed of a permanent magnet, and is capable of generating a similar field magnetomotive force with a smaller volume than a configuration in which the field magnetomotive force is generated only by a field coil. Therefore, there is an advantage that the structure can be miniaturized.

When such a permanent magnet motor is used as a motor for running an electric vehicle or the like, it is desirable that its rotational speed range be as wide as possible. To extend the rotational speed range of the permanent magnet motor, for example, Japanese Patent Laid-Open No. 61-73
The winding switching technique disclosed for the induction motor in Japanese Patent No. 591 or the like may be applied. That is, the output torque can be obtained in the high speed rotation range by switching the connection between the windings of the permanent magnet motor from the Y connection to the Δ connection during high speed rotation.

[0005]

However, in such a winding switching type permanent magnet motor, Δ from Y connection.
When switching to the connection or from the Δ connection to the Y connection, it is necessary to temporarily cut off the power supply to the motor. For example, when shifting from the low speed rotation range to the high speed rotation range, when switching from the Y connection to the Δ connection, the power supply must first be cut off, then the windings switched, and the power supply started again. If the connection is switched by such a procedure, the power supply to the motor is temporarily cut off, so that a so-called switching shock occurs.

The present invention has been made to solve the above problems, and in a winding switching type permanent magnet motor, a switching shock generated when switching winding connection or the like is reduced or The purpose is to prevent.

[0007]

In order to achieve such an object, a controller for a winding switching type permanent magnet motor according to the present invention has an output shaft connected by a differential gear so as to form a double motor structure. Rotation speed detecting means for detecting the rotation speed of the output shaft of the first and second permanent magnet motors or the rotation speed of the output shaft of the double motor structure, and the detected rotation speed is a predetermined winding switching rotation speed. A first switching torque control means for controlling the output torque of the first permanent magnet motor to 0 when crossing, and controlling the output torque of the second permanent magnet motor to the required output torque;
First connection for switching the windings of the first permanent magnet motor or the number of turns of each winding while the output torque is controlled to 0
Of the second permanent magnet motor while controlling the output torque of the first permanent magnet motor to the required output torque after the switching is performed by the winding switching control means and the first winding switching control means. Second switching torque control means for controlling the output torque of the second permanent magnet motor to zero, and second connection for switching the windings of the second permanent magnet motor or the number of turns of each winding in a state where the output torque is controlled to zero. Winding switching control means, and first and second
Torque distribution means for determining distribution of the output torques of the first and second permanent magnet motors in accordance with the required output torque after switching is performed by the winding switching control means. .

[0008]

The winding switching permanent magnet motor to be controlled by the control device of the present invention includes the first and second permanent magnet motors. The output shafts of the first and second permanent magnet motors are connected by a differential gear (differential gear) so as to form a double motor structure. In the present invention, first, the rotational speed of the output shaft of such a permanent magnet motor or the rotational speed of the output shaft of the double motor structure is detected by the rotational speed detection means. When the detected rotation speed exceeds a predetermined winding switching rotation speed, the output torque of the first permanent magnet motor is set to 0 by the first switching torque control means.
In addition, the output torque of the second permanent magnet motor is controlled to the required torque. In this state, the required output torque is exclusively carried by the second permanent magnet motor. In this state, the connection between windings of the first permanent magnet motor or the number of windings of each winding is switched by the first winding switching control means. After this switching is performed, the second switching torque control means controls the output torque of the first permanent magnet motor to the required output torque and the output torque of the second permanent magnet motor to 0, respectively. To be done. In this state, the required output torque is exclusively carried by the switched first permanent magnet motor. In this state, the second winding switching control means switches the connection between the windings of the second permanent magnet motor or the number of turns of each winding. In this way, after switching is performed by the first and second winding switching control means, the output torques of the first and second permanent magnet motors are distributed and determined according to the required output torque. .
Therefore, in the present invention, two permanent magnet motors, the first and second permanent magnet motors, are used as the permanent magnet motors that generate the required output torque, and connection between windings or switching of the number of turns of each winding is performed. Since it is performed for the permanent magnet motor whose output torque is controlled to 0, and this switching is alternately performed for the first and second permanent magnet motors,
The occurrence of shocks when switching is prevented.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a system configuration when a control device according to an embodiment of the present invention is realized in a drive system for an electric vehicle. The system shown in this figure drives and controls a double motor 12 in which the output shafts of two motors A and B are differentially connected by a differential gear (differential gear) 10.

FIG. 2 shows a schematic structure of the double motor 12. In this figure, the motors A and B and the differential 10 are housed in a single case 14.
The motor A includes a rotor 16A composed of a permanent magnet,
It has a stator composed of a stator yoke 18A and a winding wire 20A. Similarly, the motor B includes a rotor 18B composed of permanent magnets and a stator yoke 18B.
And a stator composed of the winding wire 20B. Shafts 22A and 22 of rotors 16A and 16B
Both B are connected to the differential 10. Differential 10
Is a mechanism for connecting the shafts 26A and 26B to the output shaft 24 shown in FIG. Since a known structure can be used as the diff 10, the diff 1 in FIG.
The structure of 0 is omitted.

The system shown in FIG. 1 includes a battery 26 such as a chargeable / dischargeable lead battery as a power source. The inverters 28A and 28B convert the DC power supplied from the battery 26 into three-phase AC power under the control of the ECU 30 and supply the three-phase AC power to the corresponding motor A or B via the corresponding contactor 32A or 32B. ECU3
In controlling the inverters 28A and 28B, 0 inputs a vehicle signal indicating an accelerator operation or a brake operation of a driver, and detects the rotation speed of the output shaft 24 of the double motor 12 by the rotation speed sensor 34, Generate a torque command. The ECU 30 gives a PWM (pulse width modulation) signal to each of the inverters 28A and 28B based on the torque command so that each of the inverters 28A and 28B can receive the PWM signal.
It controls the switching operation of the switching element constituting the. By performing such control, the output torques of the motors A and B can be controlled based on the torque command commanded as the vehicle signal.
The output torque of 2 (the combined torque of the output torque of the motor A and the output torque of the motor B) can be set as the output torque corresponding to the depression of the accelerator pedal by the operator, for example.

The contactors 32A and 32B are contactors for switching the windings of the corresponding motors A and B. The contactors 32A and 32B execute the switching operation under the control of the ECU 30 and indicate the state of the windings to the ECU 30. Notify me.

The contactors 32A and 32B can be configured so that the connection between the windings 20 of the corresponding motors A and B is switched between a Δ connection and a Y connection. FIG. 3 shows a contactor 3 configured to switch between Δ connection and Y connection.
An example configuration of 2A and 32B is shown.

As shown in this figure, motors A and B
Are provided with windings 20U, 20V and 20W, respectively, and U to the corresponding contactor 32A or 32B.
It is connected by 6 lines of Z. Contactor 32A
And 32B are windings 20U, 20V and 20 respectively.
The switches 36X, 36Y, and 36Z, which are realized as, for example, power relays, are provided to switch the connection between the Ws. The switches 36X, 36Y and 36Z have contacts a ₁ and a ₂ , b ₁ and b ₂ and c ₁ and c, respectively.
Have two. Each switch 36X, 36Y and 36Z
When the contacts a ₁ , b ₁ and c ₁ are turned on, the windings 20U, 20V and 20 are turned on as shown in FIG. 4 (a).
The connection between W is a Δ connection, and the contacts a ₂ , b ₂ and c
_When connected to the ₂ side, Y as shown in FIG.
It is provided to be connected.

Therefore, when the contactors 32A and 32B having the configuration shown in FIG. 3 are used in the system of FIG. 1, under control of the ECU 30, for example, the detection value of the rotation speed sensor 34 belongs to a high speed rotation range or low speed. It is possible to control whether the connection between the windings 20U, 20V, and 20W of the motors A and B is Δ connection or Y connection, depending on whether they belong to the rotation range.

Further, the contactors 32A and 32B can be configured to switch the winding numbers of the respective windings 20U, 20V and 20W of the corresponding motor A or B as shown in FIG. In this case, when the switches 36X, 36Y and 36Z are connected to the contacts a ₁ , b ₁ and c ₁ side, the number of turns of the windings 20U, 20V and 20W is n ₁ as shown in FIG. 6 (a). , N ₁ + n ₂ when connected to the contacts a ₂ , b ₂ and c ₂ . Therefore, the contactors 32A and 3 having such a configuration are provided.
When 2B is used in the system configuration of FIG. 1, the winding numbers of the windings 20U, 20V and 20W of the motors A and B are
For example, n ₁ or n ₁ + n depending on whether the detection value of the rotation speed sensor 34 belongs to the high speed rotation range or the low speed rotation range.
₂ can be controlled.

FIG. 7 shows a relationship between winding switching and torque characteristics in the contactors 32A and 32B. As shown in this figure, when the rotation speed N of the output shaft 24 of the double motor 12 detected by the rotation speed sensor 34 exceeds a predetermined value N ₀ , the motors A and B are Y-connected or the number of turns n ₁ + n. _When switching from ₂ to Δ connection or the number of turns n ₁ , the number of turns between the lines becomes smaller, so the torque characteristic shifts from the characteristic indicated by the solid line to the characteristic indicated by the broken line, and the maximum rotation speed N
_{The max value} increases and the rotation speed range expands.

FIG. 8 shows a flow of the operation of the ECU 30 in this embodiment.

As shown in this figure, the ECU 30 is
The torque command T ^* required for the double motor 12 is calculated based on the vehicle signal and the like, and the output torques of the motors A and B are controlled based on this (100). In other words, calculates a torque command T ^* that indicates the output torque required to double the motor 12, so that the output torque according to the torque command T ^* is obtained from the double-motor 12, the torque command T _A ^* and according to the motor A A torque command T _B ^* for _B is calculated. The ECU 30 supplies a PWM signal to the inverter 28A based on the obtained torque command T _A ^* and a PWM signal to the inverter 28B based on the torque command T _B ^* . As a result, the output torques of the motor A and the motor B become corresponding torque commands T _A ^* and T _B ^* , and the output of the double motor 12 becomes a value corresponding to the torque command T ^* .

The ECU 30 further determines whether the rotation speed N of the output shaft 24 of the double motor 12 detected by the rotation speed sensor 34 has crossed a predetermined winding switching point (102). The winding switching point refers to each winding 20 of the motors A and B, as indicated by N ₀ in FIG. 7.
It is the number of rotations for switching between the connection between U, 20V and 20W, Y connection or Δ connection, or the number of turns n ₁ + n ₂ or n ₁ . For example, if the rotation speed of the output shaft 24 of the double motor 12 rises and crosses the winding switching point N ₀ as the vehicle equipped with the system shown in FIG. 1 accelerates, the condition is satisfied in step 102. If so, the process proceeds to the subsequent step 104. Similarly, as the vehicle decelerates, the output shaft 24 of the double motor 12
When the number of rotations of No. 2 decreases and the winding switching point N ₀ is crossed, the process proceeds to step 104. When it is determined in step 102 that the winding switching point is not crossed, the operations of steps 104 to 112 are not executed and the operation shifts to an operation (not shown).

If it is determined in step 102 that the winding switching point has been crossed, in the following step 104, the ECU 30 causes the torque command T _A for the motor A to pass.
^{* Is set} to 0 and torque command T _B ^* for motor B is set to T
Set to ^* respectively. That is, the ECU 30 gives a torque command T ^* relating to the required output torque to the motor B, causes the motor B to generate the required output torque, and shifts the motor A to a state of inertia.

Next, the ECU 30 supplies a winding switching signal to the contactor 32A to switch the winding (106). That is, with respect to the motor A rotating by inertia, it can be considered that switching shock does not occur even if the winding switching is performed, and therefore the ECU 30 executes the winding switching related to the motor A after the execution of step 104. Contactor 32
When A is supplied with a winding switching signal from the ECU 30, the winding switching (Δ to Y, Y to Δ, or n ₁
Switching from + n ₂ to n ₁ and from n ₁ to n ₁ + n ₂ ).

In the following step 108, the ECU 3
0 gives a torque command T _A ^* = T ^* to the motor A,
Torque T _B ^* = 0 is given to the motor B. That is,
The ECU 30 sets the torque command T _A ^* so as to obtain the output torque required by the motor A whose winding has been switched, and PWM-controls the inverter 28A based on the torque command T _A ^* . Further, regarding the motor B whose winding has not been switched, the torque command T _B ^* is set so that the motor B is rotated by inertia ^.
Is set to 0, and based on this, the inverter 28B is PWM
Control.

When the motor B is inertially rotated in this way, the ECU 30 gives a winding switching signal to the contactor 32B to execute the winding switching of the motor B (110). That is, the contactor 32B executes the same winding switching as in step 106 in response to the winding switching signal supplied from the ECU 30 in step 108.

The ECU 30 thus operates the motors A and B.
After the switching of the windings of both is completed, the torque command T ^* relating to the required output torque is distributed to the motors A and B (112). That is, the torque commands T _A ^* and T _B ^* for the motors A and B are set so that the output torque of the double motor 12 becomes the required output torque, and the inverters 28A and 28B are PWM-controlled.

As described above, according to the present embodiment, since the winding switching of the permanent magnet motor A or B is executed in the state where the output torque is controlled to be 0, for example, from the low speed rotation range to the high speed. A switching shock due to winding switching does not occur at the time of shifting to the rotation range or from the high speed rotation range to the low speed rotation range. Further, even during the period when this switching operation is being executed, the output torque of the double motor 12 is held, so that the feeling of torque loss or torque hunting does not occur. Further, since the winding switching is completed in about several hundred msec, the operation shown in FIG. 8 can be completed in about 1 second. In addition, the operation of changing the torque command value for the motors A and B can be gradually executed.

In the above description, the ECU 30
The rotation speed of the output shaft 24 of the double motor 12 was detected by the sensor 32 that rotates.
The number of rotations of the motors A and B may be detected.

[0029]

As described above, according to the present invention,
Since the output torques of the first and second permanent magnet motors forming the double motor structure are alternately controlled to 0 and the winding switching is performed while the output torque is controlled to 0, switching shock is prevented. It is possible to smoothly switch the windings without generating them.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a system according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a schematic structure of a double motor to be controlled in the present embodiment.

FIG. 3 is a circuit diagram showing an example configuration of a contactor used in this embodiment.

FIG. 4 is a diagram for explaining winding switching when the contactor having the configuration shown in FIG. 3 is used, and FIG. 4A shows a state in which the wiring between the windings is Δ connection. (B) is a circuit diagram showing a Y connection state.

FIG. 5 is a circuit diagram showing an example configuration of a contactor used in this embodiment.

6 is a diagram for explaining winding switching when the contactor having the configuration shown in FIG. 5 is used, and FIG. 6A shows a case where the number of turns of each winding is n ₁ . b) is n ₁ + n
The case of a _2, a circuit diagram illustrating, respectively.

FIG. 7 is a torque characteristic diagram showing a relationship between winding switching and torque characteristics in the present embodiment.

FIG. 8 is a flowchart showing a flow of operation of an ECU in the present embodiment.

[Explanation of symbols]

10 Differential Gear (Differential) 12 Double Motor 16A, 16B Rotor 18A, 18B Stator Yoke 20A, 20B, 20U, 20V, 20W Winding 22A, 22B Shaft 24 Double Motor Output Shaft 26 Battery 28A, 28B Inverter 30 ECU 32A, 32B Contactor 34 Rotation speed sensor 36X, 36Y, 36Z Switch A, B Motor T ^* Torque command for double motor T _A ^* Torque command for motor A T _B ^* Torque command for motor B

Claims (1)

[Claims] 1. The number of revolutions of the output shaft of the first and second permanent magnet motors whose output shafts are connected by a differential gear to form a double motor structure or the number of revolutions of the output shaft of the double motor structure is detected. When the detected rotation speed crosses a predetermined winding switching rotation speed, the output torque of the first permanent magnet motor is controlled to 0, and the output torque of the second permanent magnet motor is adjusted. First switching torque control means for controlling to a required output torque, and first switching for switching the connection between windings of the first permanent magnet motor or the number of turns of each winding while the output torque is controlled to zero. After the switching is performed by the first winding switching control means and the first winding switching control means,
Second switching torque control means for controlling the output torque of the permanent magnet motor to the required output torque and controlling the output torque of the second permanent magnet motor to 0, and the winding of the second permanent magnet motor. After switching is performed by the second winding switching control means and the first and second winding switching control means for switching the connection between the wires or the number of turns of each winding while the output torque is controlled to 0. A winding switching permanent magnet motor control device, comprising: a torque distribution unit that determines distribution of output torques of the first and second permanent magnet motors according to required output torques.