空载变压器最佳投切相位的研究

Study on Optimal Switching Phase for Unloaded Transformer

为了确定能有效抑制空载变压器合闸励磁涌流与分闸过电压的最佳投切相位,首先分析了空载变压器合闸涌流及分闸过电压的产生机理;其次考虑断路器绝缘特性和机械分散性提出了空载变压器最佳目标关合相位的计算方法及最佳分闸相位的确定条件;最后搭建试验平台进行大量的分闸测量剩磁试验确定了实际最佳投切相位,在该相位进行的选相投切试验结果表明励磁涌流和过电压得到有效抑制,验证了最佳投切相位的有效性,为空载变压器投切提供了参考依据。

In order to investigate the optimal switching phase for eliminating the inrush current and breaking overvolt- age, the principle of inrush currents and breaking overvoltage on unloaded transformer was analyzed firstly. Then consid- ering insulation characteristics and deviation of the operating time of breaker, the calculation method for the optimal clos- ing instant of controlled energizing transformers and the definite condition of optimal opening phase were given. Using physical experiment platform in laboratory, the residual flux measurement was obtained by controlled de-energization ex- periments, and the actual optimal switching phase was determined. The results of controlled switching experiments show that the inrush current and overvoltage can be eliminated effectively and verify the effectiveness of the optimal switching phase. This study provides a theoretic proofs for switching unloaded transformer.