CAJ | 학술논문

为降低乌北750kV变电站220kV侧的单相及两相接地(非对称)短路电流，使其小于三相短路电流，采用变压器中性点加装小抗的方法来实现该目标。研究了变压器中性点小抗的选择，以及变压器中性点加装小抗之后，对继电保护、绝缘配合及倒闸操作的影响。结果表明，当主变压器中性点经小抗接地时，接地短路电流幅值变小，保护装置的灵敏度变差，变电站的绝缘配合不受影响。
위강저오북750kV변전참220kV측적단상급량상접지(비대칭)단로전류，사기소우삼상단로전류，채용변압기중성점가장소항적방법래실현해목표。연구료변압기중성점소항적선택，이급변압기중성점가장소항지후，대계전보호、절연배합급도갑조작적영향。결과표명，당주변압기중성점경소항접지시，접지단로전류폭치변소，보호장치적령민도변차，변전참적절연배합불수영향。
To reduce the short-circuit current(asymmetric) of 220kV side in Wubei 750kV substation, making it reach the goal of less than three-phase short circuit current, the method of transformer adding neutral small reactance was adopted to reach the goal. This paper studied the choice of transformer neutral small reactance, and the influence of relay protection, insulation coordination and brake operation. The result shows that the grounding short-circuit current amplitude decreases, the sensitivity of protection device tails away, and the insulation coordination of the substation is not affected when the neutral point of main transformer via small reactance grounding.