Abstract：When installing generator circuit breakers or load switches, 600MW and above units do not have to install standby transformer, the high-voltage shutdown power of the unit is connected to the high-voltage shutdown power from the another unit, it is usually used only as the power supply for the shutdown maintenance of the unit, unable to achieve a quick switch with the working power supply. This kind of connection puts forward higher requirements for security segment switching system. By configuring a four-power switching system in the security segment, switching between power supply is realized by fast cutting device, switching mode is flexible, operation is safe and reliable, it has certain reference significance.
2021, Vol. 22 
