An indirect rotor position estimation technique for a fault-tolerant brushless PM motor drive

This paper proposes an indirect rotor position estimation method for a fault-tolerant brushless PM motor drive that has a dual motor module on a common shaft. The technique is based on flux linkage increments of phase windings and performing multiple rotor position estimations using pairs of phases in the motor drive. The paper provides the theory of the method and presents extensive test results to demonstrate its effectiveness using off line real data obtained under various practical operating conditions including faulty states and parameter variations.