传统选相元件在风电集中接入系统中的应用研究

摘要

Three common principles of phase selection for high voltage and UHV transmission line protection are analyzed. The adaptability of phase selection is obtained. The effect of wind power accessing upon phase selector is studied by combining the theoretical analysis with the recorded data of actual wind turbines and the simulation model analysis.Research shows that the sequence impedance of wind power system varies greatly in amplitude and phase,which will affect the phase selector based on break-variable of current and steady state sequence component,but the phase selector based on fault voltage component is not affected. Finally,the improvement suggestions of phase selector in wind power system are put forward.%通过对高压及超高压线路保护常见的3种选相原理进行分析,得出了其最佳应用条件.通过理论分析、仿真模型与故障录波数据验证的方法分析了风电接入对选相元件的影响.研究表明,风电系统的故障特征使其三序阻抗在幅值和相位上均存在较大差异,导致风电场送出线保护处的各序分流系数在幅值和相位上存在较大差异,使相电流差选相元件与稳态序分量选相元件在风电侧无法可靠选相,而突变量电压原理的选相元件动作正确.最后给出了选相元件在风电系统中的改进建议.