大型火力发电厂入地短路电流影响因素研究  

Research on Factors Influencing Grounding Short-Circuit Current in Large Thermal Power Plants

作　　者：王超[1] 沈云[1] 

机构地区：[1]广东省电力设计研究院,广东广州510663

出　　处：《广东电力》2011年第3期9-13,共5页Guangdong Electric Power

摘　　要：针对发电厂发生接地故障时入地短路电流数值越来越大,导致采取通用防护措施后跨步电位差、接触电位差不能满足设计规范值的问题,以某6×1 000MW装机容量的大型火力发电厂为研究对象,利用对称分量法计算不同类型接地短路故障时各点短路电流,分析接地电阻和中性点经电抗接地对入地短路电流的影响,为发电厂的接地网设计、断路器选型、保护整定等电气设计提供依据和合理参考。Aiming at increasingly large grounding short-circuit current value under the circumstance of grounding faults in power plants,which results in failure of step potential difference and contact potential difference to meet the design value after adoption of general precautionary measures.The paper takes large thermal power plants with 6×1 000 MW installed capacity as research objects and calculates short-circuit current by method of symmetrical component under the circumstance of different types of grounding short-circuit faults;it analyzes affect of earth resistance and neutral point on grounding short-circuit current,which provides basis and reasonable reference for electrical design in power plant such as design of grounding networks,type selection and protection setting of circuit breakers.

关 键 词：不对称短路 零序阻抗 入地短路电流 接触电势 大型火力发电厂 

分 类 号：TM713[电气工程—电力系统及自动化]