无需设置箝位开关的箝位谐振直流环节逆变器

Clamped resonant DC-link inverter without setting clamped switching

为解决多数箝位谐振直流环节逆变器中需设置独立的箝位开关来对箝位过程进行控制所引起的电路损耗增大、控制较为复杂的问题,提出了一种新型无源箝位谐振直流环节逆变器。该逆变器无需设置独立的箝位开关和箝位电容,在变压器的作用下,可将该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。此外,该逆变器的零电压持续时间不受负载电流影响,直接由两个辅助开关器件控制,且这两个辅助开关器件同时导通与关断,有利于简化控制。以各个阶段下的等效电路为基础,对电路的工作过程和软开关实现条件进行分析和实验验证,结果表明开关器件实现了软开关,且在额定功率9 kW条件下,逆变器的效率达到96.5%。因此,该逆变器能够有效地提高工作效率。

A novel clamped resonant DC-link inverter was proposed to solve the pcuit loss and complex control strategy caused by setting independent clamped switching to control theclamping process in most clamped resonant DC-link inverters. T h e inverter does not need tent clamped switching and clamped capacitor. Under the action of transformer,the DC-link voltage canbe clamped at 1.1 -1.3 times of input DC-voltage, which reduced the voltage pressure effectivelysides, the zero voltage duration of tlie inverter is not affected by the load ctrolled by two auxiliary switches. A n d the two auxiliary switches are simultaneously twhich is beneficial to simplify the control strategy. According to equivalent circuits under different stages, the working process of the inverter and realization condition of the soft switching perimental results demonstrated that switching devices achieved soft switching and efficiency reached96% under the rated power 9kW . Therefore, the proposed topology can improve efficiency effective