Abstract: The reserve power supply autoputinto device is designed to increase the reliability of the power supply. However, when the bus fault occurred, the automatic switchover of the reserve power supply autoputinto device may enlarge the accident influencing scope and accident seriousness. The application of the reserve power supply autoputinto device in Guangdong Zhuhai Jinwan Power Generation Company Limited was introduced. An improvement switchover method of the reserve power supply autoputinto device was put forward. After the reserve power supply autoputinto device was improved, when the input switch tripped caused by a fault, the bus tie switch should not switch on automatically; so the switchover of the reserve power supply autoputinto device is blocked.

Key words: reserve power supply auto-put-into device, input switch, bus tie switch, automatic switch-on, blocking