Improving the voltage quality of an inverter via by-passing the harmonic current components

In this paper, a control strategy is proposed to improve the total harmonic distortion (THD) of the output voltage of an inverter. The physical interpretation of the control strategy is to connect shunt resonant filters at harmonic frequencies to the output so that the harmonic current components are by-passed and do not flow through the inverter. As a result, the voltage THD can be maintained low even when a nonlinear load is connected. Experimental results are provided to verify the analysis and design.