基于时域全量故障模型相关性判别的集群风电送出线纵联保护

集群风电系统的等效阻抗因其多变的运行方式及控制策略而难以维持稳定,导致利用故障分量构成的模型识别纵联保护原理不再适用。提出利用时域全量故障模型识别纵联保护原理,对集群风电送出线区内外故障的时域全量故障模型特征进行分析,由分析可知差动电压、电流时域全量信息在区内故障时呈现阻感特征、区外故障时呈现电容特征,由此分别提出基于阻感模型和电容模型相关性判别的保护方案,进而构建了2套保护的相关性判别式和保护判据。仿真结果表明,基于阻感模型和电容模型识别方法的时域全量故障模型相关性判别纵联保护均能适用于集群风电送出线。

Cluster wind power outgoing line pilot protection scheme based on time-domain full-frequency fault model correlation identification

The protection with identification model based on fault components is no longer suitable for cluster wind power system because the equivalent impedance of cluster wind power system could change along with its various operation modes and control strategies. To solve this problem, a pilot protection based on time-domain full-frequency fault model identification is proposed. By analyzing the characteristics of different time-domain full-frequency models of internal and external fault of cluster wind power outgoing line, it is pointed out that the time-domain full-frequency signals of differential voltage and current present the resistance-inductance characteristic under internal fault while present the capacitance characteristic under external faults, thus protection schemes respectively based on resistance-inductance model and capacitance model correlation identification are presented, and then correlation criterion and protection criterion of these two schemes are constructed. The simulative results show that the protection schemes respectively based on resistance-inductance model and capacitance model correlation identification can both fit for cluster wind power outgoing lines well.