Filter design at the output of the inverter in PMSM drives

Abstract

Purpose This paper aims to describe a simple low-pass filter to suppress torque pulsation and current harmonics in permanent magnet synchronous motor (PMSM) drives. Design/methodology/approach For the control of the PMSM, a field-oriented control algorithm is always used. The proposed filter is actually a resistance, inductance, capacitance (RLC) filter. At the output of the inverter and the input of PMSM, an RLC filter is connected. This filter suppresses current harmonics through filtering phase voltage harmonics. Analysis of the filter is achieved through frequency characteristics analysis. Findings This filter can effectively filter out the harmonic of phase voltage. Both the simulation and experiment results show that the proposed filter can effectively suppress torque pulsation and current harmonics in PMSM drives. Also, the method of selecting filter parameters and the whole control system are very simple. Research limitations implications The filter increases the design cost of the system. Practical implications The harmonics and torque ripple of phase current are greatly suppressed. Also, the loss of the PMSM reduced. Originality/value The method of selecting filter parameters and the analysis of the proposed filter are proposed for the first time.