小水电发电系统的非接地电网单相断线故障分析及诊断方法

小水电站输电线路由于运行中遭受各种复杂的环境影响,因而频繁出现断线故障问题,严重影响了电网的稳定运行。本文以含小水电系统的10kV中性点非接地电网单相断线故障为研究对象,分析了电网单相断线故障后稳态电气特性,主要包括电流、电压的变化特征。并提出一种以电流为主、电压为辅的单相断线故障的诊断方法,通过分析电流、电压的幅值与相位角是否处于故障量的阈值内,来判断单相断线故障的发生及其类型。为小水电发电系统的线路后续保护提供可靠的动作依据,提高电网运行的稳定性。最后通过MATLAB的仿真验证该诊断方法的可行性和有效性,也得到了现场实测数据的验证。

Single-phase Disconnection Fault Analysis and Diagnosis Method for Non-grounded Power Grid of Small Hydropower Generation System

The distribution network transmission line suffers from various complicated environmental impacts during operation,and frequent disconnection faults,which seriously affect the stable operation of the distribution network.This paper takes the single-phase disconnection fault of the 10kV neutral grounded distribution network as the research object,analyzes the steady-state electrical characteristics of the single-phase disconnection fault of the distribution network,including the characteristics of current and voltage changes.A diagnosis method of single-phase breakage fault with current as the main and voltage as the auxiliary is proposed.The occurrence of single-phase breakage fault is determined by analyzing whether the amplitude and phase angle of the current and voltage are within the threshold of the fault amount and its type.For the distribution network transmission line follow-up protection,it provides a reliable basis for action,and improves the stability of the distribution network operation.Finally,the feasibility and effectiveness of the diagnosis method are verified by MATLAB simulation,and the field measured data is also verified.