This article focuses on resonance overvoltage phenomenon caused by electromagnetic PT in neutral-point indirect earthing system. It also analyses ferroresonant overvoltage character, as well as some steps to prevent or eliminate resonance.
Within this model, the characteristic of fault current is simulated in different grounding modes, and so to answer the question whether or not effective traveling wave can be found in cable system whose transformer neutral point not directly grounded.
Low-current grounding power system, called neutral indirect grounded system as well, is a widely-used neutral grounded system in our medium and low voltage network. It can greatly reduce the current when earth fault occurs. However, the detection of fault current thus becomes more demanding.
小电流接地系统(Low-current Grounding Power Systems),或者称为中性点非直接接地系统(Neutral Indirect Grounded System),是目前我国中、低压配电网普遍采用的中性点接地方式,可以很大程度上减小发生接地故障时的接地电流,但是对故障电流的检测提出了更高的要求。