基于合闸电阻的变压器励磁涌流相控技术研究

Research on Phase-controlled Technology of Inrush Current Based on Closing Resistance

分析了励磁涌流产生机理,借助数学手段推导出励磁涌流与磁链、合闸相角和合闸电阻的关系,得到了最佳合闸相位的计算公式,阐述了合闸电阻抑制励磁涌流的原理。提出合闸电阻与相控技术相结合的方法,使励磁涌流抑制效果达到最佳。采用ATP暂态仿真软件,搭建了三相变压器系统仿真模型,对合闸电阻接入阻值、接入时间、相控合闸进行了仿真与分析,得出了抑制励磁涌流的最佳方案。最后,通过三相变压器空载合闸实验来验证最佳合闸相位的合理性,对减小空载变压器合闸励磁涌流有指导意义。

The mechanism of the inrush current generation is analyzed, the relationship between inrush current and magnetic chain, closing angle, closing resistance is derived by means of mathematical method, and the formula of the optimal closing phase is obtained. The principle of closing resistance to suppress inrush current is expounded. The combination of closing resistance and phase-control technology is proposed, which makes the effect of inrush current suppression to the best. Then, the simulation model of three-phase transformer system was established by using ATP transient simulation software. The simulation and analysis of value and working time of closing resistance, and phase- continUed switching are carried out, and the best scheme to suppress the inrush current is obtained. At last, through the three-phase transformer no-load closing test to verify the best closing phase of the rationality. It is instructive to reduce the closing inrush current of no-load transformer.