I. Introduction
Recently, the brushless DC (BLDC) motors have become more important because of their high efficiency, high torque per inertia ratio, minimum maintenance requirements, high reliability, and less electro-magnetic interference (EMI) problems [1]. The BLDC motor is a three phase synchronous motor having torque–speed characteristics similar to a conventional DC motor [2]. It is also known as electronically commutated motor since an electronic commutation based on rotor position is used [2]. This eliminates the noise, sparking and maintenance problems in the DC motors [3]–[5].