The electrical and mechanical performance of the power unit module in the unit cabinet is completely the same. It is confirmed that the inverter cannot work normally due to a unit failure, and can be replaced with the spare unit at the time when the device is allowed to exit.
The replacement of the power unit is carried out according to the following steps:
1) Stop, make the inverter exit the running state;
2) Cut off the high-voltage power supply and push out the high-voltage cabinet trolley (when there is a bypass cabinet. The inverter can be isolated by the isolation switch of the bypass cabinet), lock the local or remote high-voltage disconnect switch, and ground the high-voltage cabinet grounding switch;
3) Open the unit cabinet door and wait for the indicators of all units to go out;
4) Unplug the two fiber heads of TX and RX of the faulty unit;
5) Remove the R, S, T input power wiring and the L1 and L2 output connection copper bars of the faulty unit;
6) Remove the fixing screws of the faulty unit and the rail;
7) Pull out the faulty unit along the track, pay attention to light handling;
8) Place the fiber optic plug on the new unit on the replaced unit;
9) Install and wire the spare unit in the reverse order of the above disassembly;
10) The system is powered on again and put into operation.