一种用于交流电弧炉供电的三相均衡电力电子变换器设计与开发

Design and development of a three-phase balanced power electronic converter for AC arc furnace

大功率电弧炉作为非线性且无规律负荷,通过变压器直接接入电网,会引起较低的功率因数和谐波问题,不但电耗增加,同样功耗下还要求更大的电网容量支持。同时这种供电方式使其只能通过传感器采集相电压、电流操控电极升降,实现对炉温的控制,该控制方式可靠性不足,容易造成炉况不稳定、能耗高等问题。针对这些问题与不足之处,提出一种三相均衡电力电子变换器,用于电弧炉节能供电技术改造。针对电弧炉负荷特性,通过电力电子整流逆变技术抑制电弧炉闪变和高次谐波,提高功率因数,消除对电网的冲击和污染,起到节能降耗和减小石墨电极损耗的作用。

As a non-linear and irregular load,the high-power electric arc furnace is directly connected to the power grid through the transformer,which will cause lower power factor and harmonic problems,not only causing increased power consumption,but also requiring greater power grid capacity support under the same power consumption.This power supply mode makes it possible to control the furnace temperature only by controlling the electrode rise and fall through the sensor collecting phase voltage and current.This control mode has many problems such as insufficient reliability,but also easy to cause the furnace condition instability,high energy consumption.In view of these problems and shortcomings,a three-phase balanced power electronic converter for energy saving power supply of arc furnace is proposed.According to the load characteristics of electric arc furnace,the power electronic rectifier and inverter technology can restrain the flicker and high harmonic of electric arc furnace,improve the power factor,and eliminate the impact and pollution on the power grid.At the same time,it can save energy and reduce the loss of graphite electrode.