3.3 kW bidirectional charger design based on active-clamp flyback circuits

초록

A 3.3 kW bidirectional charger using an active-clamp flyback circuit with a symmetrical structure is proposed in this paper. Unlike the currently used bidirectional resonant converter, the proposed charger has a simple structure. By adopting a symmetrical design for the proposed charger, it can achieve the same bidirectional gain and efficiency in forward and reverse operation. In addition, it has the advantage of being able to respond to a wide output voltage range through simple pulse-width modulation (PWM) control. Thus, it can be applied to multi-purpose charger designs for a variety of batteries. An elementary flyback converter has the disadvantage of having electrical stress of the switch. An active-clamp circuit is applied to solve this disadvantage and to implement zero-voltage switching (ZVS) on all of the switches. Thus, high efficiency can be achieved at a high frequency using four 1200 V class silicon-carbide field-effect transistors (SiC-FETs). The feasibility of the proposed charger was verified using a prototype converter with input and battery voltages of 400 and 100-450 V, respectively.

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