基于阻抗平面分析正序极化电压的距离继电器

Analysis of Distance Relay Using Positive-Sequence Polarizing Voltage on the Impedance Plane

正序极化电压距离继电器因其极化电压构成复杂,在阻抗平面定量分析其动作行为长期以来一直是个难题。提出了以一种利用故障分量实时计算获取系统阻抗,基于阻抗平面定量分析正序极化电压距离保护动作行为的方法。推导了距离比相公式的阻抗解析表达,代入电流电压突变量计算获得的系统阻抗,使在阻抗平面上定量分析正序极化电压距离继电器的动作行为变成可能。以PSCAD构建了正反方向出口故障算例两侧,比较了两种不同极化电压距离保护的动作情况,验证了正序极化电压优于母线极化电压这一事实。

Since the composition of polarizing quantity for a positive-sequence voltage polarized distance relay is complex, analysisof its actual behavior in quantity on impedance plane has long been a puzzle to relay engineers. This essay proposes a method to analyzeactual behavior of positive-sequence voltage polarized distance relay in quantity on the impedance plane by using fault compoent to obtainimpedance calculated in real time. Firstly this essay infers the analytical representation of phase-comparing equation of the distancerelay. Secondly the system impedance calculated is substituted into the equation, which makes it become true to analyze the behavior of apositive-sequence voltage polarized distance relay on the impedance plane. Finally two calculating examples of forward/backward fault onthe bus are constructed with PSCAD and behaviors of two different kinds of quantity polarized distance relays are compared. The fact isconfirmed that the positive-sequence polarized distance relay excels the self-polarized one.