基于分相法的牵引供电系统等值阻抗分析及对距离保护的校核

Analysis on the equivalent impedances based on respective phase method in traction power supply system for electrified railway and the checkback for line distance protection

电气化铁路负荷是不对称性的负荷,对于依据序分量法求解电气参数的方法将失效。利用分相法分析了V/v型接线电铁牵引变压器的等值阻抗,并计算了各种短路情况下距离保护的最小感受阻抗,通过深入分析找到了距离保护感受阻抗的特点,在对线路距离保护进行整定计算的基础上对距离保护的整定值进行了修正,防止了距离保护的保护范围伸出牵引变低压侧,从而保证了距离保护的选择性。

The load in electrified railroad is asymmetry,so the method for calculating the eletrical parameters based on sequence component will be faulty.This paper analyzes the equivalent impedances of transformer used in electrified railway traction station with V/v structure and the minimum detecting impedances in transmission line distance protection for all kinds of faults.The detecting impedances are found by deeply analysis.And based on the setting calculation of line distance protection,the setting value of distance protection is corrected,so it can prevent the line distance protection from the false action and ensure the selectivity of protection,which is reference valuable for engineering application.