等离子切割机半桥逆变电源的设计

Design of a Half-bridge Inverter for Plasma Cutting Machines

相比全桥逆变式DC-DC变换器,半桥逆变式DC-DC变换器具有结构简单、控制方便和成本低廉的优点,适用于中小功率等离子切割机等应用场合。设计了一种采用半桥逆变式DC-DC变换器、短路引弧、闭环电流控制等特征的等离子切割机逆变电源,兼具有过热保护、过压保护和桥臂电压失衡保护功能,实现了输出电流在35 A^115 A之间连续可调的等离子切割机实物样机。切割工件实测结果表明,基于逆变电源等离子切割机的切割质量达到类激光水平。

As compared with the full-bridge DC-DC inverter,the half-bridge DC-DC inverter features a simple structure,easy control and low cost,so it is applicable to small and medium power plasma cutting machines. The prototype plasma cutting machine designed and manufactured adopts a half-bridge DC-DC inverter,short circuit arc strike and closed loop current control and can perform such functions as overheat protection, overvoltage protection and bridge arm voltage unbalance protection. The output current is continuously adjustable in the range of 35A-115 A. Results of actual measurements of work-pieces show that the cutting quality of the plasma cutting machine based on the inverter can almost reach the same level of a laser cutter.