Abstract:

Abstract:Both Hunan Huadian Changsha Power Plant Company Limited’s two units of 600 MW supercritical generators adopted generatortransformer unit connection mode.Generator transformer unit No.2 directly connects to 500 kV Shaping Substation.Due to lack of power source,
the grid is not stiff enough and existed many electromagnetic loops cannot open and operate.Hence,generating rate of unit No.2 was limited. With the fall of coal price,thermal power profit margin was increased.The competition of generation capacity between power companies became more and more serious.To outperform planned annual generation capacity, the measure of unit No.2 interconnect to the grid through the main transformer of unit No.1 was raised.To implement this,primary electrical system,surveillance system and unbuild interlock,sequential control synchronization and other related circuits were reconstructed.Unit utilization rate was increased.

Key words: ">">Keywords:">unit utilization rate">；">operation mode">；">protection device">；">safe">；">stable">；">anti ">accident measure">；">cost