DEVELOPING AN IMPROVED SWITCHING ALGORITHM FOR FOUR-PHASE BRIDGE INVERTER WITH PHASE VOLTAGE STATE DISTRIBUTION VARYING STRATEGY FOR TWO-PHASE ASYNCHRONOUS MOTOR LOAD APPLICATION

Abstract

The paper proposes a method for developing an asymmetric switching algorithm to control a four-phase bridge inverter with a two-phase asynchronous motor load, which improves the voltage state distribution rule for each phase. This method is based on changing the voltage state distribution rules according to the sine and cosine functions to control the speed of the two-phase asynchronous motor using the voltage-frequency adjustment law. The performance of the proposed method is evaluated through criteria including the mechanical stiffness characteristic, the error steady-state speed, the transient time, and the stator current characteristics of the two-phase asynchronous motor. The advantages of the proposed method are verified through the simulation process, in which the performance of the proposed method is compared to the conventional asymmetric switching methods, and other pulse width modulation method such as pulse width modulation, and sine pulse width modulation.