An error analysis of the sensorless position estimation for BLDC motors

This paper presents a novel sensorless operation technique for brushless DC (BLDC) motors and a new approach of error analysis for the sensorless BLDC motor drive. The analysis breaks down the estimated position error to its fundamental elements in the BLDC motor drive system. The position estimation error decreases the motor efficiency and produces torque pulsation. In this paper, the new approach is introduced to analyze the errors inherent in sensorless drive systems. The analysis method presented in this paper are a useful guideline for practical design of a sensorless BLDC motor drive. The same basic approach can be applied to evaluate other indirect position estimation methods for AC motors.