基于Pearson相关性的小电阻接地有源配电网接地保护

小电阻接地配电网在大量接入分布式电源后系统结构发生变化,影响传统的接地保护可靠性。针对含多逆变型分布式电源的小电阻接地有源配电网一般结构,分析了单相接地故障时各出线零序电流、母线零序电压和中性线电流特征,并根据各线路零序电流与中性线电流之间的相位特点提出了基于出线零序电流与中性线电流Pearson相关性的接地保护方案,相比于传统的接地保护,该方法大大提高了耐过渡电阻能力,可以很好的应对噪声干扰与弧光高阻接地的情况。通过仿真验证了方案的正确性。

Grounding protection of small resistance grounding active distribution network based on Pearson correlation

The structure of low resistance grounding distribution network changes after large access of distributed generators,which affects the reliability of traditional grounding protection.In this paper,based on the general structure of the low resistance grounding active distribution network with multi-inverter-interfaced distributed generators,the characteristics of the zero-sequence current of each line,zero-sequence voltage of the bus and neutral current during single-phase grounding fault are analyzed,and the grounding protection scheme based on Pearson correlation of the zero-sequence current of line and neutral current is proposed according to the phase characteristics of the zero-sequence current and neutral current of each line.Compared with the traditional grounding protection,this method greatly improves the resistance of transition resistance and can deal with noise interference and arc high resistance grounding.Finally,the correctness of the proposed scheme is verified by simulation.