谐振直流环节逆变器的过零控制

Zero-Crossing Control of Resonant DC Link Inverter

谐振直流环节逆变器的直流环节输出电压为周期性回零的直流脉冲波形。逆变器功率管为实现零电压开关 ,除了要满足一定的开关规律外 ,还必须控制在直流脉冲波形的过零处改变开关状态。本文对逆变桥功率管的过零控制作了详细分析 ,分别以谐振直流环节逆变器和结实型谐振直流环节逆变器为例 ,讨论了过零控制信号的两种检测方法 :直接检测和由控制逻辑转换检测。由分析可见 :利用实际电路控制信号之间的逻辑关系获得过零信号简洁、可靠。根据逆变器谐振脉冲保持器的工作原理 ,提出利用采样保持电路可实现功率管的过零触发 。

The output voltage of DC link in resonant DC link inverter (RDCLI) is DC pulse wave having zero crossing periodically. Power devices of inverter must be controlled in the zero level of DC pulse voltage. It not only meets certain switching rule, but also changes switching state in order to realize zero voltage switching. This paper analyzes the zero crossing control of power devices in inverter bridge in detail. Two detecting ways for zero crossing control signal are discussed, which are directly detected in RDCLI and indirect detected in rugged RDCLI. Indirect detecting is achieved by using the logic relationship between control signals, which is simple and reliable. According to the operation principle for inverter of a resonant pulse holder, a sample and hold circuit is proposed to realize the zero triggering of power devices. Finally experimental waveforms are given.