摘要
根据浦项变电站的负荷性质,提出经小电阻接地的设计方案,采取在低压侧不接地系统中增加接地点的方法。对两种常用的接地变:Z型变和Y0/Δ型变进行了说明,并分析了单相接地时接地变的电流分布。重点介绍了接地变容量的选择依据和接地变的保护配置原则,指出接地变高压侧CT在设计中应采用Δ型接线以利于整定计算。最后提出了可行的保护配置方案和继电保护整定原则,以实现保护装置在系统单相接地时能够正确跳闸切除故障。
The scheme of the neutral grounding via low resistance in Puxiang substation is put forward according to its load character istics. It takes the method of adding the neutral grounding point in the low voltage system. Two transformers of z-type transformer and Y0/Δ transformer are introduced, and current distribution in a grounding transformer when single-phase grounding occurs is analyzed. The theory of protection and capacity selection of the grounding transformer is detailed. In order to make the setting calculation easy, delta connection of CT in the high voltage of the grounding transformer should be adopted in the design. In the end, it brings forward the protection and setting schemes, making sure that relay protections can cut off the fault when single-phase grounding occurs.
出处
《继电器》
CSCD
北大核心
2004年第20期43-45,共3页
Relay
