Design of relay protection and automatic safety device for Gaobazhou Hydropower Station

In order to minimize the equipment loss and the damage to the electric power system which may be caused by various faults and abnormal operations, the main protection devices of the generator-transformer group (including the high voltage station service transformer, excitation transformer) and short approach lines and transmission lines of the 220 kV switch station at the Gaobazhou Hydropower Station have all been dualized, and provided with perfect reserve protection devices. Since the connection of the switch station is different from the conventional bridge-type connection, the protection and automatic safety device adaptable to the connection has been provided. In order to facilitate cause analyses after the event, the selected fault-wave recorder can automatically start the printer and send data to the distant control room during the accident by means of phone lines. The selected devices are of mature technology, perfect behavior, and are easy to adjust, operate and maintain, this has laid a good foundation for guaranteeing the safety of electric equipments of the power station and the stability of the electric power system.