A Novel Bidirectional CLC-T Resonant Immittance Converter for CC / CV Battery Charging

This paper proposes a novel bidirectional CLC-T resonant immittance converter with a modified secondary for electric vehicle battery charging applications. The proposed converter has inherent constant current (CC) / constant voltage (CV) charging characteristics and is operated only at the resonant frequency. The first harmonic approximation (FHA) technique is used to design the proposed 3.3 kW, 400 V input, 320–420 V output resonant immittance converter. The converter performance at steady-state in charging and discharging operation modes is validated using PSIM simulation. In charging mode, the converter delivers constant current output till the battery reaches the rated voltage. Beyond that, it delivers constant voltage output with decreasing current. The resonant tank is equivalent to CLC-T and CL in CC and CV modes. All the switches attain zero voltage switching in charging and discharging operations. The circulating losses are drastically reduced, which increases the efficiency of the proposed converter as it is operated only at the fixed resonant frequency. As no modulation technique is involved, the complexity of the controller implementation for CC / CV charging is eliminated.