Abstract: Generally,the generator-transformer unit protection of 200 MW thermal power units is equipped with program reverse power protection,but in special situations such as generator disconnection,safe shutdown faces risks. In order to prevent power production accidents,the requirements for unit shutdown and disconnection among the 25 key requirements are introduced. On the basis of analyzing the problems of safe shutdown after the disconnection of the turbo-generator,the feasible solutions are discussed.

Key words: turbo-generator, disconnection, safety shutdown, program reverse power protection, generator disconnection tripping protection, power sudden drop