Hazard source analysis and preventive measures in substation operation - Database & Sql Blog Articles

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1. Primary equipment operation (1) Circuit breaker operation.
1) For the control box (or mechanism box) of the circuit breaker, there are three-phase inconsistent intermediate relays and forced three-phase trip relays. If the circuit breaker outlets are directly tripped after accidental collision, these relays should take preventive measures and use organic The glass cover is well protected to prevent the circuit breaker from tripping when the operator resets the relay when the small switch of the circuit breaker is tripped.
2) The circuit breaker (LW type circuit breaker, etc.) with long-distance control switching small switch in the circuit breaker control box (or mechanism box) should be placed in the “remote control REMOTE position”. The circuit breaker is absolutely forbidden to change operation. The near-control operation is combined with the circuit breaker. Only after the circuit breaker is newly installed and accepted or the switch is overhauled, the “in-place” operation of the near-control and sub-breaker is allowed to be performed during the on-site trial operation. The end of the acceptance check must be placed in the “remote control” position.
Because in the loop operation process, if the circuit breaker with the near-close control switch small switch closes the circuit breaker, then the protection circuit will not be able to trip the circuit breaker (some circuit breaker control circuit its protection trip) The exit to the circuit breaker trip coil is controlled by the remote control switch, so the protection trip should be changed to the rear of the remote control switch; if the RADSS bus is close to the hand or the split circuit breaker, the lock is blocked. Poor, because the proximity control hand-joined (or segmented) circuit breaker does not start the bus-connected or segmented connection circuit. After the circuit breaker is closed, the secondary circuit of the bus-coupled or segmented current transformer is not automatically put into corresponding The difference between the points.
3) During the operation of the circuit breaker, if two-phase or one-phase non-full-phase operation occurs, it shall be implemented according to the dispatching operation regulations; if one or two phases of the circuit breaker fail to occur during the operation of the circuit, the circuit shall be disconnected. The device is opened and the circuit breaker is prohibited from being put into operation until the cause is ascertained.
4) The line is changed from hot standby to running operation. Before connecting the circuit breaker, check the voltage circuit switching of the line protection and the protection signal is normal. (Check the voltage switching relay 1YQJ, 2YQJ or voltage switching indicator, protection signal and its circuit once. The status corresponds to), 220kV bus differential protection with isolation switch position indicator should also be checked. 110kV and above equipped with microcomputer protection reflecting voltage (such as high-closed, distance protection, etc.) should also print a sample of microcomputer protection before closing the circuit breaker.
5) Spring-loaded circuit breakers (such as SW2-35) When using the control switch to close the circuit breaker, it should be noted that the energy storage light plate of the circuit breaker should have a transient process. If it is not bright or steady, it should be ascertained. The reason is (check whether the storage knife switch is pushed up, whether the energy storage knife switch fuse is blown, etc.), in case the re-closing failure occurs after the circuit breaker trips due to the spring not being stored in the line protection action. If the line needs to be powered because the motor is burnt out, the energy storage knife switch of the circuit breaker should be opened to manually store energy.
6) For circuit breakers whose outer insulation is non-electrical porcelain products, such as porcelain sleeves, SF6 circuit breakers or vacuum circuit breakers with external insulation rods being epoxy resin, it is forbidden to open the exhaust fan of the electric discharge compartment when the relative humidity of the air is too high. To prevent air convection from causing condensation on the porcelain sleeve or the insulating tie rod, so that the insulation is lowered and the ground flashover may occur. The 3AF-35 capacitor vacuum circuit breaker that has not been countered is prohibited from being put into operation when the humidity is greater than 90%.

7) After the line is disconnected and the circuit breaker is opened, if the meter reaches zero and the green light is on but the mechanical indication of the circuit breaker is still closed, the operation of the line disconnecting switch should be verified on the line side. The electric power is used to confirm that the circuit breaker is in the open position. If the side cannot be inspected, the opposite side of the dispatch request should be reported.
(2) Isolation switch operation.
1) For the 35kV system with arc-suppression coil grounding, before the operation of the arc-extinguishing coil isolating switch, it is necessary to check that the grounding indicator on the site is not lit and the arc-suppression coil is not sounding, otherwise the operation is prohibited.
2) It is found that the isolating switch supports the breakage of the insulator. If the operation of the isolating switch may break the situation that endangers personnel and equipment, the isolating switch is prohibited from operating.
3) The test operation of the busbar disconnector must be carried out under the condition that the positive and negative isolating switches of the circuit are not connected or the corresponding busbars are shut down for maintenance and the circuit breakers of the circuit are inspected. For the various isolating switches with electric coded locks, the computer key should be used, but the factory must be in the open position at one time.
4) The equipment and scope that can be pulled by the isolating switch shall be implemented in accordance with the on-site operating procedures. When an abnormality or malfunction occurs in the equipment that is allowed to be pulled by the isolating switch (such as bus voltage transformer), it shall be implemented in accordance with the abnormal conditions of the equipment and the accident handling regulations in the field operation regulations.
5) The operation of the circuit to change the hot standby and the inverted busbar. After the operation of the busbar disconnector, check the signal light and voltage switching related to the position of the busbar disconnector should be correct, and protect the no abnormal signal and drop the card. For example, when the RADSS busbar switching operation is performed, there should be no busbar blocking signal, and the double-position relay of the isolating switch should be flipped correctly. The position indicator of the busbar disconnector on the BADSS busbar of the successor is consistent with the actual, DBTl and DRR--731 protection disks. The upper isolating switch position indicator matches the actual one.
6) The remote control operation isolating switch. The button inside the remote control box must be equipped with a baffle and a mechanical code lock or security lock.
7) After the isolation switch is closed, the degree of wedge of the blade and the angle of closing should be checked to prevent the wedge from being bad after closing and the contact resistance is too large and the heat is generated.
8) Heavy-duty and loops for reverse busbar operation due to busbar disconnector heating. After the loop is reversed, the above regulations shall be followed, and the busbar isolation switch and connector shall be subjected to infrared temperature measurement.
9) For the electrically operated isolating switch, in case of electric failure, it must be found that the circuit breaker, disconnector and grounding switch with interlocking and blocking relationship with the isolating switch meet the operational requirements; the unlocking operation must comply with the unlocking operation regulations, and is strictly prohibited. Operate the isolating switch by means of the isolation switch closing and closing contactor.
2. Secondary component operation (1) connection piece.
1) Protect the connecting piece of the outlet. Before using the upper device, check that the outlet relay of the device does not operate and the device has no abnormal signal and the card is discarded.
2) After operating the operator, the operator should tighten the end button to prevent poor contact. The guardian should check whether the connecting piece is firm.
3) The relay protection personnel should remind the corresponding protection connection piece and terminal clearing during the protection check to prevent the contact failure and poor insulation.
4) For the frequency-dependent or load protection of the frequency-reduction load protection circuit, the connection piece should be used first to check the no-abnormal signal and then use the tripping connection piece and the closing lock connection piece.
5) The connecting piece that is normally deactivated should be removed. If the connecting piece is not uniform and the removal is easy to cause confusion, the upper part of the connecting piece is opened and lowered (cannot touch the other connecting piece terminal) and the end button is tightened.
6) The protective connecting piece that is not connected or used by the protective device should be removed, and the connecting piece of the pile head terminal should be wrapped with an insulating tape.
(2) Terminal.
1) After the operator operates the busbar current terminal, it should be tightened, and the guardian should review it to prevent poor contact.
2) The busbar current terminal has been operated. After the loop switch is closed, the unbalanced current should be measured.
3) Insulation pads must be used to operate the current terminals.
4) The rheological terminal in the outdoor terminal box is easy to oxidize and produce patina. The operating personnel cannot patrol the dead angle. It is found that this situation should be reported to replace the raw copper current transformer terminal.
5) Disassemble the short-circuit current terminal and then disconnect each phase current terminal and then short-circuit it. To disconnect the current terminals, first remove all shorting tabs and then connect the current terminals phase by step.
6) The current transformer current terminal has two layers, the on-current terminal should be connected to the inner layer, and the short-circuit current terminal should be short on the outer layer.
7) After the circuit is cold-falled, the busbar current terminal must be switched to the corresponding busbar (parent). If the line busbar current terminal cannot be switched, special attention should be paid to the fixed connection mode of the busbar difference. If the circuit is put into operation, the busbar should be changed first to destroy the fixed wiring mode.
(3) Switch.
1) Switching switch related to protection and corresponding signal or indication after operation (such as busbar fixed connection mode switch, self-cutting switch, voltage transformer secondary contact switch, etc.), after operation, check corresponding The indicator light or light plate is on or off. If it does not light up or does not go out, stop operation and find out the cause. The above inspection contents should be included in the operation ticket inspection step.
2) For the switch that can remove the handle, the handle should be removed in time after operation. For the universal switchable switch operation handle, only one control room can be placed (such as the universal synchronous switch switching handle of 220kV and 500kV circuit breaker). The spare operating handle is sealed by the owner.
(4) button.
1) After the important alarm indicator is illuminated, if the resetting device is likely to cause the device to malfunction, the instruction plate with the eye-catching instructions and processing steps should be attached.
2) Protect some important buttons inside the device or on the screen (such as the BIDCK button for importing the BADSS bus, the external test button for the RADSS/S busbar of the factory), and do not press it during normal operation. You should be well protected against accidental touches and a prominent indication on the button.
(5) Fuse.
1) Replace the fuses in strict accordance with the configuration requirements, and it is strictly forbidden to adjust the specifications of small fuses at will. The spare part fuse is measured with the front-end application multimeter and is confirmed to be in good condition.
2) The voltage fuse of the self-cutting device must be copper wire.
(6) Changes in protection settings.
The change of the protection value shall be deactivated according to the provisions of the site protection operation regulations. After the adjustment, the value shall be reviewed and the device shall be checked for no abnormality, and then the relevant connection piece shall be used; the microcomputer protection shall be adjusted in the fixed value area. Should be pressed later.