双零软开关弧焊逆变电源

The Double Zero Soft Switching Arc Welding Power Source

全桥零压零流脉宽调制变换器在全桥零电压脉宽调制变换器中增加一隔直电容 ,使原边电流在箝位续流时段很快的衰减到零并保持 ,固定臂的功率器件是零电流开关 ,移相臂的功率器件是零电压开关。这样 ,一方面使具有关断拖尾电流特性的IGBT可以很容易的用到全桥软开关变换器中 ,另一方面大大减少了变换器的附加环路能量 ,同时具有小的占空比损失 ,低的副边寄生振荡和宽的软开关切换的负载范围等优点。最后 ,采用上述研究成果研制了一台 10kW级采用FB -ZVZCS -PWM变换器的软开关弧焊逆变电源样机。温升试验表明 ,研制的软开关焊机的温升比同类型的硬开关焊机的温升低近 2 0℃ ,大大减少了焊机的开关损耗。同时 ,由于焊机的功率元件是零开关 ,大大减少了器件的电压、电流应力 。

The FB-ZVZCS-PWM eonverter subjoined a block capacitor into the FB-ZVS-PWM converter. At the freewheeling interval ,the primary current is attenuated fast to zero and maintained. And then, power devices of the static leg become a Zero-Current-Switch (ZCS) ,power devices of the shifted leg become a Zero-Voltage-Switch( ZVS). In this way, on the one hand the IGBT with tail current can be easily used for fullbridge soft-switching converter, on the other hand additional circuiting energy is greatly reduced. At the same time, small duty cycle loss ,lower secondary parasitic ringing and wide soft-switching load range are achieved. Finally ,based on above achievement, a 10 kW class arc welding power source prototype with FB-ZVZCS-PWM converter has been developed. Due to the considerable decrease of switching losses ,the temperature-rising of this soft-switching arc welding power source is vety low. The temperature measurement shows that it is almost 20 CC lower than that of a hard-switching arc welding power source with the same output power. At the same time ,the power devices of the arc welding power source operate under the zero-switching situation ,which reduces the current and voltage stress. Therefor the reliability of the arc welding power source is improved greatly.