控制简单的节能型单相全桥逆变器

An Energy-Saving Single-Phase Full Bridge Inverter with Simple Control

为改善单相全桥逆变器的功率变换效率,提出了一种控制简单的节能型单相全桥软开关逆变器拓扑结构.逆变器采用简单的受限单极式正弦脉宽调制方法,在每个开关周期的工作过程中,仅需切换1个主开关和1个辅助开关,而且不需要设定谐振电流阈值和实时检测负载电流来控制辅助开关,使逆变器的可靠性和实用性得到改善.在逆变器工作过程中,利用辅助电路使主开关实现零电流软开通和零电压软关断,辅助开关也能实现零电流软开通,通过降低开关损耗来实现逆变器节能运行.文中分析了电路工作过程.搭建了一台2 kW样机,实验结果表明主开关和辅助开关都实现了软切换,这为进一步研发高性能的实用新型单相全桥软开关逆变器奠定了理论和技术基础.

A topology of an energy-saving single-phase full bridge inverter with simple control is proposed to im⁃prove power conversion efficiency of single-phase full bridge inverter.Simple limited unipolar sinusoidal pulse width modu⁃lation is applied in the inverter.Only one main switch and one auxiliary switch need to be controlled in the working process in every switching period.Moreover,setting threshold of resonant current and load current need not to be designed to con⁃trol the auxiliary switch,thus improving the reliability and practicability of the inverter.During the operation of the inverter,the auxiliary circuit is used to make the main switch achieve zero-current turn on and zero-voltage turn off,and the auxiliary switch also achieves zero-current turn on.Energy-saving operation of the inverter is achieved by reducing the switching loss.In this paper,the working process of the circuit is analyzed.The experimental results on a single-phase prototype with rated power of 2 kW show that the switching devices could achieve soft-switching,which lays a theoretical and technical foundation for further research and development of a new practical single-phase full-bridge soft-switching inverter with high performance.