Harmonics Reduction Control for the Input Current of Electrolytic Capacitor-less High-Power-Factor Inverter for IPMSM

This paper describes an inverter control method for reducing the input current harmonics and vibration in an electrolytic capacitor-less inverter for an interior permanent magnet synchronous motor (IPMSM). Typically, the back electromotive force (EMF) on an IPMSM is not sinusoidal and contains harmonics caused by the rotor structure, which leads to harmonic distortion in the motor control system and generation of harmonics in the input current. Moreover, the input current vibration occurs at the source side, which is caused by resonance with the line impedance and the DC-link capacitor. This paper proposes three control methods to reduce the current harmonics distortion and vibration. The first method filters out the harmonics of the feedback d-q axis current using a notch filter. The second method compensates the d-q axis voltage references to reduce the input current harmonics. To prevent the input current vibration, the third method adds a cancellation voltage pulse to the three-phase voltage reference of the inverter. The superior performance of these proposed methods are demonstrated through experimental results. The experimental results confirm that the proposed methods meet guideline EN61000-3-2.