Coupled Inductor Based Bidirectional Resonant Converter With Sine Wave Modulation in Wide Voltage Range

This letter proposes a coupled inductor based bidirectional series resonant converter (CIBSRC). In addition, a sine-wave modulation (SWM) with fixed frequency is also proposed to achieve load independent voltage gain for wide voltage range. The proposed CIBSRC integrates a boost stage and a resonant stage by a coupled inductor which replaces boost inductor, resonant inductor, and high frequency transformer. Compared with the bidirectional integrated resonant topologies, the number of magnetic components is less. Under proposed SWM, only one set of pulsewidth modulation signal is needed and zero voltage switching (ZVS) of all switches could be realized. Besides, the resonant current is a sine-wave which can simplify ZVS analysis and reduce current harmonics. A 500-W prototype with 100–200 V input voltage and 360 V output voltage was built and the results proved the reliability and validity.