基于移相全桥ZVS-PWM变极性焊接电源的设计

Design of variable polarity welding power supply based on phase-shifted ZVS-PWM

针对提高变极性焊接电源的整机效率和可靠性,设计了基于移相软开关变换的变极性焊接电源。电源一次逆变采用移相软开关控制,并结合具体的变换过程,给出了实现零电压软开关变换的参数设计。一次逆变输出经过全桥硬开关二次逆变以及前后极的协调控制,实现占空比和正负半波幅值独立调节的变极性输出特性。运用PSPICE对系统电路进行仿真分析,通过仿真结果得出实现软开关变换的条件以及该电路拓扑结构的缺点,验证了一次逆变桥在一定工作范围内,能够可靠地实现零电压软开关变换。

A variable polarity welding supply was developed based on ZVS-PWM(PWM:pulse width modulation) for improving overall efficiency and reliability.The design of components for achieving zero-voltage switching(ZVS) is described through the process of soft switching.By means of the second inverter based on hard-switching and the coincident-control between the first and the second inverter,the variable polarity output can be achieved,which duty ratio and output current can be adjusted independently.Finally,based on the simulation of the system by PSPICE,conditions for achieving soft-switching and shortages of the topology were described.It can be proved by the simulation that the zero-voltage switching can be achieved reliably under a given conditions of the load.