三相大功率焊接逆变电源的网侧电流谐波抑制
Harmonic Elimination Input Current for a Three-phase High Power Arc Welding Inverter
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摘要: 逆变焊接电源改善了焊机的效率和控制性能,但是却提高了焊机输入电流的谐波畸变水平。有源功率因数校正技术通过电力电子元件的开关作用来消除非线性负载的谐波电流,使来自电网的电流是正弦波。本文分析了焊接逆变电源的功率因数和输入电流谐波畸变的关系,提出了一种连续电流输入的三相功率因数校正电路的方案,其连续的正弦电流输入是通过采用平均电流控制技术实现的。谐波抑制方案的理论分析通过数字仿真结果进行了验证。一台10kW样机的部分试验结果例证了三相功率因数校正电路的工作过程。Abstract: The arc welding inverter improves system efficiency and controllability.Their applications,however,increase the harmonic distortion level of the input current. Active power factor correction technique uses power electronic switching to cancel the harmonic currents from a nonlinear load. So that the current being supplied from input line is sinusoidal. This paper analyses relationship between the power factor and input current distortion of the inverter power source. A three-phase configuration of a new power factor correct circuit that makes use of continuous input current is suggested. Continuous sinusoidal input current is achieved by the average current mode control technique. The theoretical analysis is verified with digitally simulated results. The selected experimental results from a laboratory prototype rated at 10kW demonstrating the three-phase power factor correct circuit operation are also presented.