DC brushless motor system for drainage pump, control method and control device thereof

Abstract

Disclosed are a control method and a control device for a brushless DC motor for a drainage pump, and a brushless DC motor system for a drainage pump. The control method of the brushless DC motor for a drainage pump includes: after the rotational speed of the brushless DC motor reaches a first predetermined rotational speed, the duty cycle of the voltage pulse supplying power to the stator winding of the brushless DC motor is equal to the duty cycle of the brushless DC motor. The first critical duty cycle is compared; and when the duty cycle of the voltage pulse is lower than the first critical duty cycle, it is determined that the drainage pump has entered a half-water, half-air operating state, and the The target rotation speed of the brushless DC motor is set to a second predetermined rotation speed, wherein the second predetermined rotation speed is lower than the first predetermined rotation speed. The half-water-half-air state of the drainage pump is identified based on the duty cycle of the voltage pulses supplied to the stator winding, and the half-water-half-air noise is reduced by reducing the target speed of the brushless DC motor in this state.

Description

Technical field [0001] The present invention relates to the technical field of drain pumps. More specifically, the present invention relates to a control method and control device of a DC brushless motor for a drain pump of a household appliance, and a DC brushless motor system for a drain pump of a household appliance. Background technique [0002] At present, single-phase AC permanent magnet synchronous motors are widely used in the field of drainage pumps for household appliances such as dishwashers and washing machines with their high energy efficiency and excellent steady-state characteristics. However, single-phase AC permanent magnet synchronous motors have certain limitations in terms of starting and running performance. [0003] For example, in the application of washing machine drain pump, in order to solve the problem of heavy load and easy burning of the motor when the drain pump is started, it is necessary to add a starting device. The starting device is mainly compose...

AI Technical Summary

Problems solved by technology

The disadvantage of this control method is that the residual water cannot be completely discharged through the motor, so it does not completely solve the problem of half-water and half-air noise during the drainage process

[0006] With the introduction of the concept of green home appliances and the enhancement of environmental protection awareness, the existing drainage pumps can no longer meet the increasing requirements for the comfort of the living environment.

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