基于电流变化率与短路合闸角综合判据的船舶交流电网短路故障方向判断

Fault Direction Judgment for Shipboard AC Network Based on Integrative Criterion of Change Rate of Current and Fault Initial Angle

对船舶交流电网三相与两相短路电流变化率的特性进行理论分析,研究短路合闸角、功率角及线路阻抗等参数对短路电流变化率的影响,分析短路初始阶段电流变化率的正负极性与短路故障方向之间的对应关系,在此基础上,提出基于电流变化率与短路合闸角的短路故障方向综合判据。应用该判据,通过检测和比较短路合闸角与短路初始阶段电流变化率的正负极性,即可实现短路故障方向的快速判断,因而对采样精度要求不高,所需的实时数据量和计算量较少。仿真结果验证了该短路故障方向判断方法的有效性。

In this paper,the characteristic of change rates of three-phase and two-phase shortcircuit currents for shipboard AC network are theoretical analyzed.The effects of fault initial angle,power angle and line impedance on the change rates of short-circuit currents are studied.The relation between fault direction and polarity of change rate of initial short-circuit current is analyzed.Based on the analysis results,an integrative criterion of fault direction judgment using change rate of initial short-circuit current and fault initial angle is proposed.Using the criterion,the fault direction can be rapidly judged by detecting and comparing the fault initial angle and polarity of change rate of initial short-circuit current with less requirements of sampling precision,real-time date and computing capacity.Simulation results verify the validity of the proposed method of fault direction judgment.