Washing machine motor drive device

• US 20030020431A1
• Filed: 07/02/2002
• Published: 01/30/2003
• Est. Priority Date: 07/19/2001
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Hagiwara, Hisashi, Kiuchi, Mitsuyuki, Tamae, Sadayuki, Kondo, Norimasa
• Granted Patent: US 6,737,828 B2
• Time in Patent Office: Days
• US Class Current: 318/779
• CPC Class Codes: D06F 2103/04 Quantity, e.g. weight or variation of weight
• CPC Class Codes: D06F 2103/24 Spin speed; Drum movements
• CPC Class Codes: D06F 2103/44 Current or voltage
• CPC Class Codes: D06F 2105/48 Drum speed
• CPC Class Codes: D06F 34/18 Condition of the laundry, e.g. nature or weight
• CPC Class Codes: D06F 37/304 Arrangements or adaptations of electric motors
• CPC Class Codes: H02P 21/06 Rotor flux based control involving the use of rotor position or rotor speed sensors
• CPC Class Codes: H02P 21/36 Arrangements for braking or slowing; Four quadrant control
• CPC Class Codes: H02P 27/08 with pulse width modulation
• CPC Class Codes: H02P 6/085 in a bridge configuration
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers

Abstract

A washing machine motor drive device for driving a motor using an inverter circuit, which implements a constant torque control through a change in the torque-revolution speed characteristic of a motor. It facilitates an easy control of braking torque (negative torque), thereby providing a maximized braking torque. An easy control of regenerative energy is also provided, and the back electromotive force is consumed by the internal resistance of motor. Practically described; DC power of rectifier circuit connected to an alternating current source is converted by an inverter circuit into AC power for driving a motor for operating an agitator or a washing/spinning tub, motor rotor position is detected by rotor position detector, motor current is detected by current detector, control device controls the inverter circuit for resolving motor current into a current component corresponding to magnetic flux and a current component corresponding to torque. At the motor braking operation, the current component corresponding to magnetic flux and the current component corresponding to torque are controlled independently. As the result, the torque at high speed revolution can be increased, or the efficiency at low speed revolution can be improved. This leads to a downsized and energy-conscious motor, and contributes to the prevention of an abnormal rise of DC voltage in the inverter circuit.

Claims

1. A washing machine motor drive device comprising

an alternating current source,

a rectifier circuit connected to said alternating current source,

an inverter circuit for converting DC power of said rectifier circuit into AC power,

a motor driven by said inverter circuit for driving an agitator or a washing/spinning tub,

rotor position detector for detecting rotor position of said motor,

current detector for detecting current of said motor, and

control device for controlling said inverter circuit;

wherein

said control device resolves said motor current into a current component that corresponds to magnetic flux and a current component that corresponds to torque, and controls said current component corresponding to magnetic flux and said current component corresponding to torque independently in accordance with the control stage of said motor.

2. The washing machine motor drive device of claim 1, wherein

control device controls current component corresponding to magnetic flux and current component corresponding to torque independently in accordance with revolution speed of a motor.

3. The washing machine motor drive device of claim 1, wherein

control device controls the current component corresponding to magnetic flux so that it is increased in the negative direction when motor revolution speed is high.

4. The washing machine motor drive device of claim 1, wherein

control device controls the current component corresponding to magnetic flux so that it becomes substantially zero when motor revolution speed is low.

5. The washing machine motor drive device of claim 1, wherein

control device controls the current component corresponding to magnetic flux so that it is increased in the negative direction when motor revolution speed is high for driving a washing/spinning tub for dehydration operation.

6. The washing machine motor drive device of claim 1, wherein

control device controls the current component corresponding to magnetic flux so that it is increased in the negative direction when motor revolution speed is high for driving an agitator for washing operation.

7. The washing machine motor drive device of claim 1 further comprising clothes amount detector for detecting amount of clothes in a washing/spinning tub, wherein

control device controls the current component corresponding to magnetic flux and the current component corresponding to torque independently in accordance with amount of clothes detected by said clothes amount detector.

8. The washing machine motor drive device of claim 1 further comprising start control device for controlling motor revolution at the start of revolution provided in the control device, wherein

control device makes a direct control on the voltage to be applied to motor at the start of revolution by means of said start control device, and then controls the current component corresponding to magnetic flux and the current component corresponding to torque independently.

9. The washing machine motor drive device of claim 1 further comprising start control device for controlling motor revolution at the start of revolution provided in the control device, wherein

control device makes a direct control on the voltage to be applied to motor at the start of revolution by means of said start control device, and then controls the current component corresponding to magnetic flux and the current component corresponding to torque independently in accordance with revolution speed.

10. The washing machine motor drive device of claim 1, wherein

control device controls said current component corresponding to magnetic flux and said current component corresponding to torque independently at motor braking operation.

11. The motor drive device of claim 10, wherein

control device controls the current component corresponding to torque so that it meets a specified value at motor braking operation.

12. The motor drive device of claim 10, wherein

control device controls the current component corresponding to torque so that it is specified in the negative value at motor braking operation.

13. The motor drive device of claim 10, wherein

control device controls the current component corresponding to magnetic flux and the current component corresponding to torque independently so that they meet respective specified values at motor braking operation.

14. The motor drive device of claim 10, wherein

control device controls the current component corresponding to magnetic flux so that it is greater than the current component corresponding to torque at the start of motor braking operation.

15. The motor drive device of claim 10 further comprising revolution speed detector for detecting revolution speed from the output signal of rotor position detector, wherein

control device controls the current component corresponding to magnetic flux and the current component corresponding to torque independently in accordance with revolution speed so that they meet respective specified values at motor braking operation.

16. A washing machine motor drive device comprising

an alternating current source,

a rectifier circuit connected to said alternating current source,

an inverter circuit for converting DC power of said rectifier circuit into AC power,

a motor driven by said inverter circuit for driving an agitator or a washing/spinning tub,

rotor position detector for detecting rotor position of said motor,

current detector for detecting current of said motor,

DC voltage detector for detecting DC voltage of said inverter circuit, and

control device for controlling said inverter circuit;

wherein

said control device resolves said motor current into a current component that corresponds to magnetic flux and a current component that corresponds to torque, and controls said current component corresponding to magnetic flux and said current component corresponding to torque independently so that said DC voltage meets a specified value at said motor braking operation.

17. The motor drive device of claim 16, wherein

control device controls the current component corresponding to magnetic flux, or the voltage component, so that DC voltage of inverter circuit meets a specified value at motor braking operation.

18. A washing machine motor drive device comprising

an alternating current source,

a rectifier circuit connected to said alternating current source,

an inverter circuit for converting DC power of said rectifier circuit into AC power,

a motor driven by said inverter circuit for driving an agitator or a washing/spinning tub,

rotor position detector for detecting rotor position of said motor,

current detector for detecting current of said motor,

motor electric power detector for detecting power of said motor, and

control device for controlling said inverter circuit;

wherein

said control device resolves said motor current into a current component that corresponds to magnetic flux and a current component that corresponds to torque, and

controls said current component corresponding to magnetic flux and said current component corresponding to torque independently in accordance with said motor electric power at said motor braking operation.

19. The motor drive device of claim 18, wherein

motor electric power detector makes calculation based on the power component corresponding to magnetic flux and the power component corresponding to torque for performing a control.