高频脉冲VPPA焊接电源系统建模与仿真

Modeling and simulation of VPPA welding power system of high-frequency pulse

建立了IGBT式双逆变高频脉冲VPPA焊接电源系统模型,包括双逆变主电路及其PWM控制电路。计算并获得了在一次逆变频率固定的前提下可输出高频脉冲与滤波电感的对应关系。由仿真结果可知,降低输出滤波电感值,可在一定范围内提高输出脉冲频率,但滤波电感值过低会使输出电流不连续,因此,通过降低滤波电感值来提高可输出高频脉冲频率是有限的。由仿真结果还发现,在滤波电感一定时,提高一次逆变频率会提高可输出高频脉冲频率,但逆变频率过高对开关器件要求极高,增加设备保护系统的复杂程度。计算结果可以为研制高频脉冲VPPA焊接电源系统提供理论依据。

Simulation model of IGBT-type double inverter VPPA welding power system of high-frequency pulse was established in the paper, including the double inverter main circuit and PWM control circuit. Under steady frequency of first inverter, the corresponding relations between the output high-frequency pulse and filter inductor was calculated and obtained. The simulation results indicated that, in a certain range,reducing the value of output filter inductance could improve the output pulse frequency. Lower filter inductance would make the output current discontinuous. It was limited that by reducing the inductance value to improve the output frequency of high-frequency pulse. The simulation results also was found that the frequency of output high-frequency pulse was raised by improving an inverter frequency. The requirements for switching devices increase the further, the inverter frequency become higher and add complex degree of equipment protection system. The results of the calculation could supply theory evidence for developing VPPA welding power system of high-frequency pulse.