摘要
本文首先分析了距离保护基本原理,并讨论了光伏电站接入对送出线路距离保护、配电网距离保护、配电网重合闸和选相元件的影响。进而,以光伏电站表现出的故障特性为依据,同时本着工程应用方便且误差允许的前提,提出了光伏电站类比常规电源的短路计算模型,即电压源串联阻抗的形式,并针对光伏电站不同的故障特性给出了二者各序阻抗的计算公式。将给出的计算模型加入到常规电网短路电流计算模型中,分析了计及光伏电站的电网短路电流计算模型及故障特性,研究了规模化光伏接入后对地区电网短路水平的影响。通过距离保护建模、阻抗整定值设定、电流起动门槛值设定等,建立了算例模型,仿真验证了送出线路在不同位置、不同类型故障下保护的动作情况,得出了光伏并网对距离保护配置、重合闸配置、选相元件的若干建议。
The basic principle of distance protection is analyzed firstly. And the effect on transmission line, distance protection in distribution networks and automatic reclosing by PV power station are discussed. Based on the fault characteristics of PV power station and in the premise of convenient project application with allowable error, a model of PV power station short circuit is presented. The model is in voltage source impedance in series form. The fault characteristics of PV power station with different calculation formula of two different sequence impedance is given. The calculation model is added to the conventional grid short-circuit current calculation model. The short circuit current of power system with photovoltaic power station calculating is completed in the model. Based on the segment impedance sets setting of distance, the setting of current starting threshold value, the simulation model is set up. The influence of large-scale photovoltaic access on the short circuit level of regional power grid is studied. The protection starting of transmission lines with different positions and different types of fault phase current is verified. Also the distance protection starting with different positions and different types of faults is verified. Finally, some suggestions are given for the distance protection configuration, reclosing configuration and phase selection element of the grid connected photovoltaic system.
出处
《电气技术》
2017年第11期25-31,38,共8页
Electrical Engineering
关键词
光伏电站
距离保护
重合闸
选相元件
PV power station
distance protection
automatic reclosing
phase selection element
