Reduction EMI due to di/dt and dv/dt DC and AC sides of BLDC motor drive

High speed Brushless DC Motors (BLDCM) are widely used in automated industrial applications like subsystem of submarines, aerospace applications and in the field of robotics. But due high speed switching circuits used in the commutation circuits, the BLDC motor causes high electromagnetic interference (EMI) problems. Since the subsystems of aerospace device and vehicle are close together, EMI reduction is important challenge for aerospace applications. EMI has adverse effects on radio communications. In this paper, a simple and new method is presented to design passive filters to reduce EM emissions in BLDCM drives. This method is applicable to many ac drives. Since the high frequency model is used usually to predict exact EMI frequency spectrum approximately and is not essential to assessment ability of the proposed method in reducing EMI, typical model of BLDCM drive system is used in this paper that helps to this paper goal analyzing will be easy.