A Study on Redundant Detection Method for BLDC Motor Rotor Position

Detection of rotor position is one of the key factors that affect the reliability of BLDC motors. According to the guide lines for redundant configuration of rotor position sensor of the brushless motor,this paper presents a dissimilar redundancy scheme using Hall elements and resolver. It analyzes the logical relationship between the output of these two types of sensors and the optimal phase change,and presents fault judgment criteria for different sensors after a discussion on their operational characteristics. Furthermore, a 2-stage error tolerance management strategy( mutual angle detection + level comparison) is designed on the basis of the output information of the sensor. Finally,system reliability of 0. 996 9 is achieved through reliability modeling and prediction,higher than that of the similar redundancy of two groups of Hall elements by 31. 47%. The experimental results prove the effectiveness of this redundancy scheme and error tolerance strategy.