Identification and Suppression of Electromagnetic Noise of Variable Reluctance Resolver for Hybrid Electric Vehicle

Following the development of electric and hybrid vehicles, permanent-magnet synchronous machines (PMSMs) have been widely used as traction motors. In most PMSM drives, the rotor position sensor is required for reliable torque control. A variable reluctance resolver has been adopted as a position sensor in automotive industries thanks to its mechanical reliability in a harsh environment. Because the resolver signal is analog, the signal is vulnerable to the noise caused by electromagnetic interference such as common-mode voltage and external magnetic field. In this paper, the source of electromagnetic noise in the target motor system is identified experimentally. From finite element analysis (FEA), the noise path to the position signal of the resolver is identified. Furthermore, a strategy to suppress the noise is devised and evaluated with FEA and verified experimentally with an actual motor.