Analysis of failure protection output the other sides of the transformer and open voltage block on transformer unit

Busbar protection and transformer protection is main element protection in substation. In tradition,the protection zone is specific limit,is nothing cooperation problem between busbar protection equipment and transformer protection equipment. But according to development power grid in China,it brings up the problem failure protection output the other sides of the transformer and open voltage block on transformer unit. This paper analyzes these problems and provides a solution,which can be used as a reference to personnel of electric power project and technique standard.