【摘要】 在Y0/Y0或Y0/Δ接线的变压器的Y0侧非常接近中性点处或Δ侧接近顶点处发生相间短路时,由于短路的匝数很少,短路电流很小,任何保护都可能拒动,亦即任何保护都具有一定的死区。该文分析Y0/Y0接线变压器纵差动保护死区的存在以及影响死区大小的因素,推导死区边缘两相短路时差电流的计算公式,作为保护整定的依据。更多还原

【Abstract】 When phase fault is close up to the neutral point at the Y0 side and near the apex at the Δ side of the Y0/Y0 or Y0/Δ wiring transformers, because the short circuit turns are few and the short circuit current is small, any protection may refuse to operate, that is any protection has certain dead-zone. The existence of the longitudinal differential protection dead-zone of Y0/Y0 wiring transformers and the factors affecting the size of the dead-zone are analyzed. The calculation formula of differential current when two-phase short-circuit happens at the edge of the dead-zone is deduced, which is regarded as a basis for protection setting.更多还原