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15 procedures for switching operation of high-voltage electrical equipment

source:English website  |  Release time:2022年12月16日
1. The operation of power failure shall follow the sequence of switch, load side knife switch and power side knife switch, and the switching operation of power transmission shall follow the reverse sequence of the above, and it is strictly prohibited to pull and close the knife switch with load.
2. If a power outage operation task includes the power outage of one or more buses, it is allowed to open all the switches that should be powered off one by one, and then open the corresponding knife switches one by one; The power transmission operation can also be carried out according to the above principles.
3. The operation of the switch must be checked for effectiveness. If the primary circuit is switched to hot standby in an operation task, the effect inspection after opening the switch must be set up separately; Other situations shall be replaced by checking the actual position of the switch before opening and closing the knife switch.
4. After double circuit lines or transformers that can operate in parallel (including transformers used) are paralleled, meter indications of two circuits shall be checked before and after splitting to judge the correctness of operation results.
5. Before closing or opening the knife switches on both sides of the switch, check that the switch is in the open position.
6. When the substation with bypass bus carries out the operation of reversing the bypass bus, check that the knife switches of all the outgoing lines of the bypass bus are in the open position, and set a separate check item.
7. Operation of switching DC fuse (operating DC switch): In case of power failure, the operating DC fuse shall be switched off immediately after the switch is switched off (positive first, negative second); During power transmission, after other operations are completed, put the DC fuse into operation before closing the switch.
8. During the maintenance of switches and knife switches, the DC fuse and power fuse (DC power plug-in) shall be opened; When switching hot standby, the DC fuse is not opened; The power fuse may not be opened during cold standby, hot standby and line maintenance of the switch.
9. The reclosing device shall be put into operation, and the shutdown operation procedure shall be stopped and put into operation along with the opening and closing of the switch. During power transmission, the reclosing device shall be put into operation after the switch is closed, and in case of power failure, the reclosing device shall be stopped before the switch is opened.
10. When the equipment is powered on, the tripping strap of corresponding protection shall be at the input position. For protection regular inspection or other operations involving protection circuits, the input and shutdown of protection shall be included in the operation items; The operation mode of protection may not be changed for the operation not involving the protection circuit. Temporary protection loop operation or protection affected by system operation mode change, and protection that should be stopped or put into operation by dispatching order, shall be operated according to dispatching order.
11. Power failure, power transmission, paralleling and splitting of transformers shall be carried out according to the following principles:
① Before the power failure and transmission of the transformer in the 110 kV substation, the 110 kV neutral point knife switch shall be closed first, and the zero sequence protection of the main transformer (zero sequence protection main outlet, zero sequence protection tripping 110 KV bus coupler) shall be put into operation during the closing of the neutral point knife switch.
② In general, the power transmission operation procedures of the main transformer (including all transformers of the same voltage level) are charging at the high voltage side and sending out at the low voltage side, and the power outage operation procedures are power outage at the low voltage side and power outage at the high voltage side. When the low-voltage side is operated with a generator, the sequence shall be determined according to the switch position equipped with synchronization.
③ Operation basis of 35 kV bus coupler pressing plate for main transformer compound voltage lockout overcurrent tripping: if the time limit of 35 kV bus coupler tripping for main transformer compound voltage lockout overcurrent is the same as that of 35 kV outgoing line backup protection, the protection pressing plate for operating main transformer shall be disabled when a single main transformer is operating; If the time limit for overcurrent tripping of 35 kV buscouple due to composite voltage lockout of main transformer is higher than the time limit for backup protection of 35 kV outgoing line, the protection strap of operating main transformer may not be disabled when a single main transformer is operating.
④ If the operation task requires changing the operation mode of the used transformer, the operation of switching the used transformer shall be completed before the operation of high-voltage equipment, and the check items shall be set in the switching operation ticket to ensure reliable AC working power supply.
12. Bus switching operation:
① 110 kV bus charging shall be completed by bus coupler switch with charging protection.
② If the 35 kV bus has charging protection, the bus coupler switch shall be used to complete the charging operation during charging, otherwise the 35 kV main switch of the main transformer shall be used to complete the charging operation; The charging of 6 kV bus shall be carried out according to this principle according to the actual situation.
③ When charging the empty bus with a 110 kV switch with a breaking capacitor, it is necessary to prevent the capacitor from resonating with the bus voltage transformer.
13. When installing the grounding wire, the grounding wire for dispatching management shall be installed first, and then the grounding wire managed by the substation itself; The sequence of removing the grounding wire is reverse.
14. When installing the grounding wire, the provisions that the grounding wire should be installed immediately after the electricity inspection should be implemented, without interruption. When installing grounding wires on both sides of the switch in the switch cabinet, the grounding wires shall be installed respectively after the power inspection on both sides of the switch.
15. The grounding end of the grounding wire in the high-voltage switch cabinet shall be installed at the visible position at the lower front end of the switch cabinet, and the signboard "No closing, someone working!" shall be hung on the operating handle of the knife switch on the live side to prevent the knife switch with the grounding wire from being closed. After the trolley switch is pulled to the maintenance position, the switch cabinet shall be locked.