Permanent magnet synchronous motor current ripple reduction with harmonic back-EMF compensation

This paper presents a current ripple reduction strategy for space vector controlled permanent magnet synchronous motor (PMSM). Motor harmonic back-EMF induced by the rotor permanent magnet influences the current control performance. Referring to motor phase voltages based on the mathematical calculation using ideal motor voltage equation, a comparison of motor terminal voltages with their reference is given and the harmonic back-EMF components are extracted and applied to the motor three phase windings as compensation. Simulation and experimental results of the current and voltage, produced by a commercial PM synchronous motor drive system using space vector control are presented. These results are compared with those results without compensation to verify the effectiveness of the proposed voltage compensation strategy.