Safety operation

In December 2003, the State Council issued a Notice on strengthening power security operation, in which SERC is authorized to take the responsibility for power supervision and management, the State Grid Corporation and China Southern Power Grid Co., Ltd are clarified to take the responsibility for operational security in respective power grids. These two large power grids have in turn issued separately No.1 instructions, which call for “enhancing dispatching management, safeguarding power grid safe and stable operation”.

Power grids in China achieved excellent performance that still maintained neither vast area blackout nor system collapse fault happened in 2003.

Power demand and exchange in power grids

Power demand nationwide appeared still vigorous in 2003, both power generation and supply tended consistently to be high with higher increase rates. The national electricity supplied amounted to 1719 TWh and electricity sold amounted to 1509 TWh, the line losses accounted for 7.71%, a little higher than the previous year. The change of line losses is shown in Fig.1.  

Fig.1 Line loss trends in recent years 

Power exchange between large regional power grids, regions and provinces accumulated to 163.6 TWh in 2003, in which, electricity exchanged 33.7 TWh between large regional grids and 134 TWh across provines, or autonomous regions power grids. In Southern Power Grid, 19.5 TWh electricity were sent from west to Guangdong and 5.36 TWh were sent to Guangxi power grid in 2003. The power output and consumption load in power grids in 2003 are shown in Table 1.

Table 1 The power output and consumption load by grids by the end of 2003 

Operational reliability

The reliability indexes of 13 categories transmission and substation equipment nationwide in 2003 were basically equal to those in 2002, and maintained on a higher level, all availability factors were kept above 99%. The national average power supply reliability (RS1) was 99.866%, a little lower than the previous year, but after deducting the factor of electricity quota due to power shortage, the supply reliability (RS3) still maintained an increasing trend, reached a record of 99.929%.

By the end of 2003, power grids in China hadn’t occurred serious fault such as power system instability or collapse in successive 7 years, the power system frequency qualification rate in main power grids reached above 99.99%.