Second harmonic current reduction by using a resonant circuit in a single-phase battery charger

This paper discusses a battery ripple current effect on battery lifetime and mitigation of the second harmonic current in a single-phase battery charger for residential use. A new L-C resonant circuit is added to reduce the second harmonic current component which flows into battery bank. The second harmonic component reduction method is analyzed with an equivalent circuit of battery model, resonant circuit and charger circuit, and design rule is discussed. Ratio of battery second harmonic current to dc current is decreased to 3.2% from 32.7% by adding the proposed L-C resonant circuit. Feasibility of the reduction method is verified by simulation and experiment.