Analysis and application of two-phase spindle motor driven by sensorless BLDC mode

Abstract

This thesis analyzes the two-phase structure spindle motor driven by sensorless BLDC mode, which offers a special method to solve the starting problem caused by the high-speed HDD. The sensorless BLDC drive system for two-phase spindle motor is built up, and the optimal commutating angle based on constant voltage mode is discussed. The performances of two-phase spindle motor are tested. Both the simulation and experiment results show that the proposed drive system is correct and efficient. The starting capability of two-phase spindle motor is analyzed and tested, and compared with three-phase spindle motor. And based on the conventional stepping drive mode, an improved starting method is introduced, which can enhance the starting capability of two-phase spindle motor. The results show that the proposed two-phase spindle motor drive has potential to solve the starting problem of the high-speed spindle motor, which is very concerned in the new generation HDD.