High-Efficiency Sine-Wave Current Pulses Charging Method in Wireless Power-Transfer System Applications

Abstract

There has been extensive discourse surrounding energy storage equipment and technologies for sustainable energy solutions. To address the need for prolonging the operational lifespan of energy storage equipment, this research introduces a high-efficiency charging method that integrates wireless power-transfer (WPT) technology. In the proposed LLC-S charger, the diodes of the receiver side rectify the incoming power while generating interleaved sinusoidal wave current pulses for charging two lead-acid battery energy storage systems (BESSs). This approach offers the advantage of providing rest intervals for BESSs and mitigating the impact of electrochemical reactions, thus promoting their overall durability. To validate the proposed charger, two 60 V/14 Ah BESSs as storage equipment within the solar power system are utilized for the charging tests. The results revealed that the utilization of sine-wave current pulses for charging enabled soft switching at both the transmitter and receiver sides, resulting in an overall average efficiency exceeding 80%. Experimental data derived from a prototype with a maximum output power of 1391 W during charging demonstrated that BESSs could be fully charged in a mere 1.61 h, achieving an impressive efficiency of 98%. These findings substantiate the feasibility and effectiveness of utilizing sine-wave current pulses for charging.