Torque ripple and EMI noise minimization in PMSM using active filter topology and field-oriented control

This paper proposes an active filter (AF) topology to reduce the torque ripple and harmonic noises in a permanent-magnet synchronous motor. The topology consists of an insulated-gate bipolar transistor AF and two resistance-inductance-capacitance high-pass electromagnetic interference (EMI) noise filters, i.e., one in the primary and the other in the secondary circuit of the coupling 1:1 transformer. The AF is characterized by detecting the harmonics in the motor phase voltages by comparing the measured phase values with the reference voltages generated as a function of the motor parameters and control setting values under field-oriented control. The AF uses the hysteresis voltage control method, while the motor main circuit uses the hysteresis current control method; thus, the two control methods independently work together to provide an almost sinusoidal voltage to the motor windings. The simulation results show total harmonic distortion drops of greater than 13% with EMI noise damping down to ∼ -10 dB as well as considerable reduction in torque ripple. © 2008 IEEE.