DRIVE CONTROL METHOD FOR BLDC MOTOR IN USING WASHING MACHINE

摘要

A drive control method of a BLDC motor used for a washing machine is provided to remove a riffle of a DC link voltage by preventing rapid variations of supply voltage, current, and speed caused due to interception of input power and momentary power failure. A DC link voltage and a speed sensed in a high-speed dehydration process are compared a first reference voltage and a first reference speed, and then an input voltage interception mode is checked by a compared result(SP11). An input interception voltage for controlling D-axis and Q-axis currents and a current limitation value are set to form constantly the DC link voltage when the input voltage interception mode is determined by the compared result(SP12). The D-axis and Q-axis currents are reduced according to a constant gradient in order to prevent a dropping effect of a supply voltage and the DC link voltage is reduced by setting the voltage for intercepting the input voltage, the current, and control variables when the present speed is more than a second reference speed(SP13-SP15). A feedback process is performed by determining the present state as the power failure when the DC link voltage is more than a second reference voltage(SP16). A PWM gate is turned off to limit the supply of current when the DC link voltage is less than the second reference voltage(SP17).