单相全桥谐振直流环节软开关逆变器

为提高逆变器的效率和简化控制方式,提出一种单相全桥谐振直流环节软开关逆变器。通过单独开关控制辅助谐振电路,使直流环节电压在逆变器主开关需切换时下降到零,逆变器的主开关可以实现零电压开关,同时辅助开关也可以实现零电压开关。而且,逆变器直流环节电压不会超过直流源电压。由于谐振过程和零电压持续时间都较短,因而可以减少功率消耗和提高直流电压的利用率。依据不同工作模式下的等效电路,分析其工作原理,结合相平面分析法研究其动力学行为,给出了软开关实现条件和参数设计过程,搭建了实验样机。实验结果表明逆变器的主开关和辅助开关都实现了软开关,可以有效地降低该软开关逆变器的开关损耗和提高其效率。

Single-phase full-bridge resonant DC-link soft-switching inverter

A single-phase full-bridge resonant DC-link soft-switching inverter was proposed to improve the efficiency and simplify the control method.When main switches in the inverter needed operating,the DC-link voltage decreased to zero via the single switch which controlling the resonance of the auxiliary circuit.Then all main switching devices in the inverter were operated under zero-voltage condition and auxiliary switching device was also operated under zero-voltage condition.The voltage across the DC-link inverter devices was limited to the input source voltage.Because the process of the resonant and the zero-voltage time was short,it could reduce the power loss and improve the efficiency by using the DC-source voltage.The operation principle was analyzed based on the equivalent circuits at different operation modes.The phase-plane analysis technique was established in order to study transient dynamics.The conditions of soft-switching and the process of parameter design were also achieved.A laboratory prototype was built.The experimental results demonstrate that soft-switching operation of all switching devices are realized.Therefore,the soft-switching inverter presented effectively reduces switching loss and improves efficiency.