零序直流系统漏阻对整流管导流状态的等效变换

Equivalent Transformation of the Leakage Resistance According to the Conducting State of the Rectifying Tube in the Zero-Sequence DC System

零序直流系统整流管对微小检测电流的导流性能需要进一步认识,本文选择电网漏电状态,建立整流管各导通时段的电路模型,研究漏阻变化与检测源共接点电位之间的关系,揭示了漏阻高于临界值[2]之后共接点电位的变化趋势,它接近于检测源限流电阻与共接点取样电阻互易位置检测电网接地状态形成的电位值。经假设、验证、拉格朗日插值实验,证明存在一漏阻值可以使两检测源共接点电位相等。显然,只要能合理选取检测源内电路参数,检测源对高漏阻的检测特性就可以与检测低漏阻时相同。

It needs further study on the conducting capability of the rectifying tube to the tiny detected current in the zero-sequence DC system. This article chooses the leakage state of the power system, and sets up a circuit model of each conducting time of the rectifying tube. It studies on the potential relation between the change of the leakage resistance value and the common nod of the detection source. It reveals the diversification tendency of the common nod potential, when the value is larger than the critical one. It approaches to the detected potential value formed by the grounding state of the power net in which the limit-current resistance of the detection source exchanges the position with the sample resistance. Through supposition, validation, and Lagrange experiment, it proves that there is a leakage resistance which can make the potential values at the common nods of the two detection sources equal to each other. Apparently, its detection characteristic of the high value of the detecting leakage resistance can be in the same case of the low one, as long as the inner circuit parameters of detection source are selected in a reasonable way.