Compensation of dead-time effects based on revised repetitive controller for PMSM drives

This paper presents a new dead-time compensation method for voltage-source inverters (VSI) used in PMSM drives. The proposed method is developed based on the revised repetitive controller (RRC) to reduce current distortion caused by dead-time voltage errors at the inverter output. This method significantly suppresses the sixth order harmonics and it's multiples in synchronous reference frame and reduces the current total harmonic distortion (THD). Unlike in most average value theory based compensations, the proposed method doesn't require additional hardware for precise current sampling especially in the zero-crossing region. The algorithm is integrated to 2.5 kW PMSM drive controlled by FOC. It is quite immune robust to motor parameter variations due to the nature of repetitive control. Its effectiveness is validated by experimental results and spectrum analysis.