A study on the Development of Sensorless Driver for Electric Compressor Brushless DC Motor

전동식 컴프레서 브러시리스 직류 전동기용 센서리스 드라이브 개발에 관한 연구

In this paper, In the whole industry, there is a tendency to replace brushless motors with brushless motors because of the high rate of failure in DC motors with brushes. Accordingly, many methods for driving a brushless motor have been developed and studied. In order to drive the brushless motor, it is essential to know the information about the rotor position of the motor. However, it is not possible to use a position sensor for rotor disconnection due to the structure of an electric compressor brushless DC motor. In this paper, we investigate the rotor position of the motor by using the counter electromotive force included in the voltage of the terminal made by Y connection by using the resistance of each phase without using Hall sensor or encoder generally used to detect the rotor position. A sensorless drive system for a square wave brushless direct current (DC) motor is proposed. To do this, we propose a method to detect the rotor position from the analyzed terminal voltage waveform by performing terminal voltage analysis of each phase for 3-phase, 2-exciton unipolar PWM.