母线保护常规和复式比例制动差动元件灵敏度和安全系数计算分析

Calculate and Analysis to Sensitivity and Stability of Conventional & Complex Ratio Restraint Different Relays for Busbar Protection

分析了母线保护常规和复式比例制动差动元件的动作特性,推导出常规制动系数和复式制动系数的对应关系,得出2种差动元件在母线区内故障不拒动和区外故障不误动的边界条件。提出区内故障伴随汲出电流情形下2种差动元件灵敏度和区外故障伴随故障支路误差电流下2种差动元件安全系数的计算方法。计算给出不同制动系数、电流汲电比和误差下差动元件灵敏度和安全系数数据表,绘制相应曲线族,直观揭示比较2种差动元件在区内故障的灵敏性和区外故障的安全性。

The principles and characteristics of conventional complex ratio restraint different relays are analyzed and compared in this paper. Bases on this point,the relationship between two restrain ratios and operating bord are deduced and discussed. Considering the difference of current distribution between interior and exterior busbar fault,The method for calculating sensitivity and stability of two kinds of differential elements is proposed. Sensitivity for interior fault is calculated quantificationally as well as the stability in exterior fault,which respectively attended by outflow of the fault current and TA error. Protracting the tables and curves for sensitivity and stability,characteristics of conventional complex ratio restraint different relays are revealed intuitively.