First, the busbar grounding knife lock blocking implementation:
(1) Mechanical locking:
The mechanical linkage component of the installation position knife gate is used to block the busbar grounding gate operation to prevent the grounding of the grounding switch.
(2) Electrical blocking:
In the grounding switch control bus loop, parallel string into the auxiliary contacts bus segment all-switch-side, only the relevant disconnectors are all turned off in a state before the operation division grounding switch, the grounding switch together antistatic .
(3) Microcomputer blocking:
Design standard computer five anti-locking logic, the operation of the computer monitoring system must meet the five anti-logic verification, then open operation, local box operation, must also be verified by five anti-logic, can only open the five anti-lock operation after meeting the conditions Loop.
The microcomputer locking logic at this time includes: all the knife gates on the busbar side of this section are in the disconnected position.
2. The electrical lockout between the busbar side knife gate and the busbar grounding knife gate is missing.
For the busbar grounding knife gate and the knife gate, under normal circumstances, the busbar grounding knife gate is arranged on the corresponding knife gate, and there is perfect mechanical locking between the two, even if there is no electrical locking, because of the existence of mechanical locking, When the gate of the busbar grounding knife is in operation, it is theoretically possible to prevent the grounding of the grounding switch. However, when the knife gate of the busbar grounding knife gate is in the state of inspection, the mechanical latching will lose the latching effect. For example, when only the busbar PT is inspected, the busbar PT knife gate is disconnected at this time, and the busbar grounding knife gate loses the mechanical lockout due to the disconnection of the busbar PT knife gate.
As shown above, in the case of the disconnection of the busbar PT, the mechanical lockout between it and the busbar grounding of the busbar will lose the latching effect on the busbar grounding switch. There are several situations:
(1) The busbar grounding knife does not have the remote control function. At this time, since there is no remote control loop, if it is necessary to operate the busbar grounding switch, it must be operated from the local. At this time, the operation must pass the microcomputer five anti-locking, in theory, the possibility of connecting the grounding knife with the busbar can be avoided.
(2) The busbar grounding knife gate has remote control operation. If the operator needs to operate the busbar grounding switch, it must be carried out from the monitoring system or the local facility box. Both of these operations must be verified by the microcomputer five anti-locking logic or verified by the local computer five anti-locking. In theory, there is no possibility of the grounding of the busbar with the busbar. At this time, due to the existence of the remote control loop, other personnel mistakenly move the busbar grounding knife at the monitoring machine, the measuring and controlling screen, and the switch terminal box. Because the busbar PI' knife gate is in the open state, the busbar grounding knife gate and the busbar PT knife gate The mechanical lockout does not work , so a malicious misoperation accident with the grounding knife of the busbar will occur .
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Third, the proposed temporary preventive measures
In order to prevent accidental operation accidents before the electrical lock between the busbar side knife gate and the busbar grounding knife gate is completed, it should be discussed technically and effective temporary preventive measures should be taken .
From the analysis point of view, the busbar side cutter and the grounding knife gate with remote control function may cause dangerous points of misoperation, which are all on the circuit before the knife gate or the grounding knife mechanism box. Then to prevent misoperation, the direct measure is to disconnect the operating power of the electric knife gate and the grounding knife gate, so that even if the control loop is turned on even if the motor is not operated, the knife gate or the grounding knife gate will not operate.
There are two places where the motor power of the knife gate (grounding knife) can be disconnected:
(1) Disconnect the knife gate (grounding knife) in the mechanism box (motor operation power switch;
(2) Disconnect the motor operating power switch of the knife (grounding knife) in the switch terminal box.
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4. Is the motor operating power supply disconnecting the knife gate (grounding knife gate) affecting the normal operation of the equipment?
Since the knife gate (grounding knife gate) is different from the switch, it does not bear the function of breaking the circuit with the protection device, but only needs to form a clear breaking point or grounding measure for the circuit. Therefore, in normal operation, disconnect the knife gate (grounding knife) motor operating power supply
Does not affect the normal operation of the device. Below we analyze the two ways to disconnect the power:
(1) Disconnect the knife (grounding knife) mechanism motor power switch in the mechanism box:
When disconnecting the motor operation power switch from the knife gate (grounding knife) mechanism box and performing the knife gate (grounding knife gate) operation, the knife gate (grounding knife gate) motor must be closed in advance to operate the power switch. The grounding knife gate is equipped with five anti-mechanical padlocks, which cannot be opened. Therefore , the remote operation of the device cannot be performed remotely . It is necessary to use the computer key to operate in the local mechanism box, which does not meet the requirements of the operation of the self-station.
(2) Disconnect the switch in the switch terminal box (grounding knife) motor operation power switch:
Disconnect the knife (grounding knife) motor from the switch terminal box to operate the power switch. Because the switch terminal box is not equipped with five anti-locks, when the knife gate (grounding knife) is operated, the switch terminal box can be opened to close the switch in advance. (Grounding knife gate) The motor operates the power switch, and then performs remote control operation , which can meet the operation requirements of the comprehensive station.
Therefore, it is recommended to disconnect the electric knife (grounding knife) motor operating power supply from the switch terminal box during the implementation process .
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