基于瞬时无功理论的点焊机无功补偿

Research on reactive power compensation for spot welding based on instantaneous reactive power theory

针对点焊机引起的功率因数低、三相负荷不平衡等电能质量问题,在分析TSC补偿原理的基础上提出了基于瞬时无功理论改进的无功电流检测方法,并采用一种基于无功电流的大小和变化率的快速投切控制算法。根据点焊机的实际工况,Matlab/Simulink仿真显示所采用的无功电流检测方法和快速投切算法能够在30 ms左右完成无功功率补偿,且补偿后的功率因数达0.95以上。仿真结果表明,所提出的用于不平衡负荷无功功率补偿的方法具有较好的动态跟踪性和静态补偿效果。

In view of power quality problems such as low power factor and unbalanced three-phase load caused by spot welding loads, an improved reactive current detection method based on instantaneous reactive power theory is proposed and a fast switching control algorithm based on reactive current and its rate of change is used. According to the actual working condition of the spot welding loads simulation with reactive current detection method and fast switching algorithm is done in Matlab/Simulink ,and the resuhs show that reactive power compensation can be completed in about 30 ms and the power factor is more than 0.95. It shows that the proposed method for unbalanced load reactive power compensation has better dynamic tracking property and static compensation effect.