In an electrolytic-capacitor-less single-phase to three-phase inverter, the resonance between the line inductance on the source side and the DC-link capacitor causes an input current ripple. In this paper, a new approach for suppressing the input current ripple due to this resonance is described. This paper proposes a new control method that does not emulate the action of the damping resistor for passive damping. The proposed method cancels the resonance by using a DC-link capacitor discharge actively. In the proposed method, a cancellation voltage pulse that cancels the resonance is added to one of the three-phase voltage references for the inverter. The cancellation voltage is calculated by feeding back the variables relative to the discharge. The effectiveness of the proposed method is validated by experimental results.
2017 The Institute of Electrical Engineers of Japan