基于故障性质判断法的配电网中性点动态接地成套装置的开发及应用

Development and Application of a Complete Set of Neutral Grounding System for Distribution Network Based on the Judgment of Fault Nature

通过对配电网中性点经消弧线圈接地方式,以及小电阻接地方式的特点分析及存在的问题进行了更加深入地研究,并开发研制出了配电网中性点动态接地成套装置。该装置具备消弧线圈接地与小电阻接地方式二者的优点,又能够灵活地解决两者存在的缺点。其功能在于配电网发生单相接地故障时,依据故障特征量和参数,就可以对故障的性质进行智能判断。满足在瞬时性接地故障时,故障点的绝缘水平能够快速恢复,提高了电网供电可靠性;同时在永久性单相接地故障时,能够快速且准确地选出,并切除故障线路,确保了设备和人身安全。经大量实验及运行结果证明:从消弧线圈接地方式分析,配电网中性点动态接地装置解决了接地选线和人身安全得难题;而从小电阻接地方式角度分析,解决了供电可靠性和高阻接地时零序保护"失灵"的问题,因此该装置是当前配电网中性点接地的理想产品。

Based on the distribution network neutral point grounding via arc suppression coil,a more in-depth analysis of the characteristics of small resistance grounding mode and the existing problems,and developed a dynamic distribution network neutral point earthing device. The device has the advantages of arc suppression coil grounding and small resistance grounding mode,and can flexibly solve the defects existing in the two. Its function is that when the single-phase fault occurs in the distribution network,the quality of the fault can be intelligently judged by means of fault characteristic parameters and parameters. Meet in the transient grounding fault,the insulation level of the fault point fast recovery,improve the reliability of power supply;at the same time in the permanent single-phase grounding fault,can quickly and accurately select,and remove the fault line,ensure that the equipment and personal safety. After a lot of experiments and operation results show that from the analysis of arc suppression coil grounding,power distribution network neutral point grounding device solves the dynamic grounding line selection and personal safety problems;while the small resistance grounding mode analysis,solve the power supply reliability and high resistance grounding zero sequence protection 'failure'the problem,so the device is an ideal product for grounding distribution network neutral point current.