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

Abstract

A control method and control device of a direct current brushless motor for a drain pump, and direct current brushless motor system for the drain pump, the control method comprising: when the rotation speed of a direct current brushless motor reaches a first predetermined rotation speed, comparing the duty ratio of a voltage pulse supplying power for the stator winding of the direct current brushless motor with a first critical duty ratio; and when the duty ratio of the voltage pulse is lower than the first critical duty ratio, determining that the drain pump is in a half-water half-air operation state, and setting the target rotation speed of the direct current brushless motor as a second predetermined rotation speed, the second predetermined rotation speed being lower than the first predetermined rotation speed. The half-water half-air state of the drain pump is identified according to the duty ratio of the voltage pulse supplying power for the stator winding, and half-water half-air noise is reduced by reducing the target rotation speed of the direct current brushless motor in the half-water half-air 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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