零序互感对线路接地距离保护的影响分析

Zero-sequence mutual inductance on the ground distance elements impact analysis

以接地距离保护动作方程为蓝本,运用电力系统故障计算软件这样的工具,从分析双回线之间的零序互感对接地距离保护测量阻抗值的影响入手,阐述了在接地距离保护整定计算中应计及线路零序互感的必要性,并举例分析了零序互感对接地距离保护测量值大小的影响趋势。为了消除这一影响,提出了含零序互感参量的用于精确测量的零序电流补偿系数概念,整定计算接地距离保护定值时,要考虑零序互感的影响,按最不利条件,并应把零序互感对接地距离保护测量阻抗的影响计算到保护定值中去。

Taking the action equation of the ground distance elements as the prototype, this paper points out that mutual inductance value of zero-sequence is essential to settings of the ground distance elements, while using the power system failures calculation software, considering the impact of double lines between the zero-sequence mutual inductance to measurement of the ground distance elements. The effect of zero-sequence inductance mutual on distance measurement is illustrated. In order to eliminate the impact, the concept of zero-sequence mutual inductance parameters for the accurate measurement of the current compensation coefficient of zero sequence is brought put. In the end, this paper considers the impact of zero-sequence mutual inductance, on the assumption of the most adverse conditions, and adds the impact to measurement of ground distance elements up to the calculation of settings.