陕西电网330kV“12.5”主变故障差动保护动作分析

330kV main transformer differential relay operation analysis of 12.5 fault in Shaanxi Power Grids

详细分析陕西电网330kV"12.5"主变压器故障时差动保护装置的故障电流波形和数据,梳理主变区内、外故障的实际过程,研究主变内、外部故障特征和差动保护在区内、外转换复杂故障情况下的动作行为,查明保护动作原因,对变压器差动保护原理提出改进意见和建议。指出国产变压器抗短路能力不能满足IEC和国标的抗短路水平要求,建议主变制造厂家优化主变的结构和制造工艺,提高主变的制造质量。

By thorough investigation of ＂12.5＂ 330kV transformer fault in Shaanxi power grids, the fault current waves and data from the transformer differential relays are analyzed. The actual transformer fault evolution sequence and relay operation behavior under the characteristics of external fault to coexistence of internal and external faults has been studied. The operation causes of relays are also put forward. Therefore, the suggestions of operating principles of transformer differential relays are presented. Finally, it concludes that the indigenously manufactured power transformer was unable to meet IEC and GB standard when high fault current level occurred in tertiary winding and transformer structure and manufacturing technique should be optimized by the manufactures to raise the transformer quality level.