How is the power distribution room delivered? What is the power transmission method?

Time of issue:2023-06-30


What is a power distribution room? Presumably, most electrical personnel are very familiar with it. However, when it comes to the order of shutdown and power transmission in the power distribution room and the operation process of power transmission, many electrical personnel may have little knowledge, and even some electrical personnel do not know everything. We all know that the power distribution room is also called the power distribution station. In the national standard, the definition of the power distribution station is: "There are only high-voltage power distribution devices for switching and distributing electric energy in the station, and there is no main transformer on the bus." The difference between a power distribution station and a substation is that the power distribution room (power distribution station) has no transformers, and all transformers are transformed. When the power distribution room sends power, it should generally be closed from the switch on the power supply side to the switch on the load side in turn. According to this procedure, the closing current of the switch can be minimized, which is relatively safe; in case there is a fault in a certain part, it is easy to find. So what is the order of stopping and sending power in the power distribution room? What about the power transmission operation process?


01 Shutdown and power transmission sequence of the power distribution room:


The most important thing is that the order of stopping and sending power must not be mistaken:

Power-off and power-transmitting sequence: When power off, stop the low voltage first and then stop the high voltage.

When stopping the low voltage, first stop the switches of the low-voltage branches, then stop the low-voltage main switch, and stop the control circuit first, and then stop the main circuit. The order is reversed when power is sent.

When stopping the high voltage, stop the circuit breaker first, and then pull the isolation switch. If the high-voltage incoming line has double isolating switches, first pull the load-side isolating switch, and then pull the power-side isolating switch, and the order is reversed when power is transmitted.

It is strictly forbidden to pull and close the isolating switch with the load.


02 Power transmission operation process of power distribution room:


The power transmission operation procedure is as follows:

1) After checking that no one is working on the electrical installations in the entire power distribution room, remove the temporary grounding wire and the signboard. When removing the grounding wire, first remove the line end, and then remove the grounding end.

2) After checking that the switches of the two incoming lines WL1 and WL2 are in the off position, close the contact isolating switch between the two high-voltage busbars WB1 and WB2, so that WB1 and WB2 can run in parallel.

3) Turn on all the isolation switches on WL1 one by one, and then turn on the incoming circuit breaker. If the closing is successful, it means that WB1 and WB2 are intact.

4) Connect the isolating switches of the voltage transformer circuits of WB1 and WB2, and check whether the power supply voltage is normal.

5) Close the isolating switches on all high-voltage outgoing lines, and then close the circuit breakers on all high-voltage outgoing lines to send power to the main transformers in all power distribution rooms.

6) Turn on the knife switch on the low-voltage side of the No. 2 distribution house owner's transformer, and then turn on the low-voltage circuit breaker. If the closing is successful, it means that the low-voltage busbar is intact.

7) Check whether the low voltage is normal through the voltmeter connected to the two low-voltage buses.

8) Turn on the knife switches of all low-voltage outgoing lines in the No. 2 power distribution room, and then close the low-voltage circuit breaker, or close the low-voltage fuse-type knife switch, so that all low-voltage outgoing lines will be powered. So far, the entire high-voltage power distribution station and its attached workshop substation have all been put into operation.


If the power distribution room is to resume power transmission after a power outage, the operating procedure is related to the type of switch installed in the power distribution room. If the power supply line is installed with a high-voltage circuit breaker, the circuit breaker will automatically trip when a short-circuit fault occurs on the high-voltage bus.


After the fault is eliminated, the circuit breaker can be closed directly to resume power transmission. If a high-voltage load switch is installed on the power supply line, after the fault is eliminated, the fuse tube of the fuse can be replaced before the load switch can be closed to transmit power.


If the incoming line of the power supply is a high-voltage isolating switch-fuse installed, after the fault is eliminated, replace the fuse tube first, disconnect all outgoing switches before closing the isolating switch, and finally close all outgoing switches to resume power transmission. This must also be done if the power inlet is installed with a drop-open fuse.