Sensorless Sine-Wave Controller IC for PM Brushless Motor Employing Automatic Lead-Angle Compensation

Abstract

This paper presents an advanced sensorless permanent magnet (PM) brushless motor controller integrated circuit (IC) employing an automatic lead -angle compensator. The proposed IC is composed of not only a sensorless sinewave motor controller but also an isolated gate -driver and current self-sensing circuit . The fabricated IC operates in sensorless mode using a position estimator based on a sliding mode observer and an open-loop start-up. For high efficiency PM brushless motor driving, an automatic lead angle control algorithm is employed, which improves the efficiency of a PM brushless motor system by tracking the minimum copper loss under various load and speed conditions. The fabricated IC was evaluated experimentally using a commercial 200 W PM brushless motor and power switches. The proposed IC was successfully operated without any add itional sensors , and the proposed algorithm maintained the minimum current and maximum system efficiency under 0 to 0.8 N∙m load conditions. The proposed IC is a feasible sensorless speed controller for various applications with a wide range of load and spee d conditions.