电力系统稳态第1章解读.ppt

中性点经消弧线圈接地的应用 3-6kV 电力网 (接地电流 30A) 10kV 电力网 (接地电流 20A) 35-60kV 电力网 (接地电流 10A) 补偿方式 过补（ILIc），一般采用这种方式 欠补（ILIc） 全补（IL=Ic），不允许，容易谐振 3.中性点直接接地系统 优点:非故障相电 压不变. 缺点:单相短路电 流大. 4.三相四线制系统 系统中一相接地的特点比较 中性点不接地 中性点直接接地 电流 中性点电压 非故障相 电压 线电压 接地点的电容电流是正常运行时一相对地电容电流的3倍 故障相电流和流入故障点的电流很大 中性点电压升高为相电压 故障相和中性点电压为零 非故障相对地电压仍为相电压 非故障相对地电压升高为线电压 与故障相相关的线电压降低为相电压 三相之间的线电压保持与正常时相同 经消弧线圈接地:适当选择线圈感抗,接地点电流可减小到很小,且熄灭接地电流产生的电弧。其他特点与不接地系统基本相同。 * This is a sketch map for nationwide interconnection in 2010. The power deficits in NEPN will be mainly filled up by the Humeng’s thermal base. NEPN is to be connected with NCPN to obtain interconnection benefits. NCPN and NWPN will be probably interconnected along with the development of Sanxi thermal power base. In the same time, it will strengthen interconnection between NCPN, NWPN NEPN and Shangdong as well as ECPN and CCPN. Also, it will be possible that Northeast China power system will be imported electricity from Russia. The TGPG will make CCPN, ECPN, CYPG as well as NCPN interconnect. In future, TGPG will be interconnected with Southern China Interconnected Network to obtain trans valley compensation benefit. A ±500kV HVDC line is planned to be built in order to transmit thermal power from Shanxi to Sichuan. FJPN will be interconnected with ECPN to save reserve of generation. Shaanxi in NCPN will supply thermal power to SDPG. When all planned interconnection projects are completed, most of regional and provincial power grids will be interconnected and a nationwide interconnected grid will be basically established. * This is a sketch map for nationwide interconnection in 2010. The power deficits in NEPN will be mainly filled up by the Humeng’s thermal base. NEPN is to be connected with NCPN to obtain interconnection benefits. NCPN and NWPN will be probably interconnected along with the development of Sanxi thermal power base. In the same time, it will strengthen