并网异步风电场短路特性的仿真分析

风速的随机性与间隙性使风电场经常处于不同的运行方式,合理的保护配置是保证风电场及接入系统稳定运行的卫士。短路特性是保护配置的前提和依据,针对恒速异步风力发电机组,讨论了其数学模型,分析了异步机组的电磁暂态过程,建立了风电场联络线路接地故障时,风电场提供的短路电流各序分量表达式,对影响风电场故障特性的主要因素进行了分析,并以PSCAD/EMTDC为平台建立风电场并网运行的仿真模型,研究了风电场投入系统容量、风速、故障类型、X/R对故障特性的影响,仿真结果与理论分析相吻合。研究结果表明风电场继电保护整定时应考虑这些影响因素,以提高风电场继电保护动作的有效性和可靠性。

Simulation Analysis of Short-Circuit Characteristic on Wind Farm Interconnected Grid

Due to the nature stochastic and intermittent of wind speed,wind farm always run in different manners,rational relay protection promise wind farm and power system to operate stability,short-circuit characteristic is foundation which can rationally layout relay protection. Based on constant speed induction wind generator,analyze the math model and electric transient and establish the phase sequence current model of wind farm when faulty is present in the line connecting wind farm to power system,the main factor that influence short-circuit characteristic is analyzed. A simulation model is established on the PSCAD / EMTDC platform,the factors of faulty characteristic are studied,including the capacity of wind farm,wind speed、faulty type、faulty location、and X / R etc,the results of simulation are identical with theoretical analysis. These influence factors should be considered when we design the relay protection of wind farm ,it is helpful to enhance the effectively and liability of relay protection.