箝位二极管承受低电压的有源箝位谐振直流环节逆变器

Active Clamped Resonant DC-Link Inverter with Clamped Diode Under Low Voltage

为解决无源箝位谐振直流环节逆变器辅助电路中采用耦合电感辅助换流(即抽头电感法)所引起的箝位二极管两端承受的电压应力过大问题,提出一种箝位二极管承受低电压的有源箝位谐振直流环节逆变器,该逆变器采用有源箝位的方法可使箝位二极管两端承受的最大反向电压不超过直流母线电压的最大值.且该逆变器的辅助谐振电路中只有一个辅助开关器件,箝位电路中无需设置箝位开关,控制简单且硬件成本较低.此外,在箝位电路的作用下可将逆变器的直流母线电压箝位在输入直流电压的1.1~1.3倍,有效地降低了电压应力.以各个阶段下的等效电路为基础,对电路的工作过程进行了分析,并进行了实验验证,实验结果表明开关器件实现了软开关,且在额定功率3k W条件下,逆变器的效率达到96.5%.因此,该拓扑结构能够有效地提高工作效率.

A novel active clamped resonant DC-link inverter is designed to solve the problem that clamped diode is under high voltage stress caused by coupled inductors that was tapped inductor method in passive clamped resonant DC-link inverters. The maximum voltage of the clamped diode in the clamped circuit did not exceed the maximum voltage of DCbus voltage by using active clamped method. There is only one auxiliary switch in auxiliary resonant circuit,and it did not need to set clamped switch,so it is easy to control and the cost of hardware is lower. Besides,under the action of clamped circuit,the DC-link voltage could be clamped at 1. 1 ~ 1. 3 times of input DC-voltage,which reduced voltage pressure effectively.According to equivalent circuits under different stages,the paper analyzed the working process of the inverter.The experimental results demonstrated that switching devices achieved soft switching and efficiency by 96. 5% under the rated power 3 kW. Therefore,the proposed topology can improve efficiency effectively.