Safety control points in the dispatching operation

2022-10-02
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Safety control points in unattended substation dispatching operation

1 Load control

with the development of economy and the improvement of people's living standards, the power load presents large-scale regeneration particles, and the range rises. Some transmission (distribution) lines are full load and overloaded to varying degrees due to their early construction and thin wire diameter. The dispatcher should grasp the load development of the system in time, have a certain predictability of the load development, and put forward solutions to prevent tripping, equipment burning and other accidents due to overload. In particular, 35kV and above transmission lines will cause power failure of the whole substation, with a great impact. The preventive measures taken are to pay attention to the change of load flow, prepare the limit of each line, and set the limit exceeding alarm of line equipment

for the substation with two main transformers operating in parallel, when one of the main transformers needs to be out of operation for maintenance, the dispatcher should pay attention to controlling the load. If the load exceeds the overload capacity of another main transformer, the load transfer operation shall be carried out first, and then the main transformer shall be shut down to prevent the main transformer from tripping due to overload. In addition, when the bus is changed from parallel operation to separate operation, the dispatcher should pay attention to the load of each bus section to avoid the overload tripping of the main transformer due to the unbalanced load distribution

2 relay protection

relay protection device is one of the main technical measures to protect the safe and stable operation of electricity. The dispatcher shall be familiar with the basic principle of relay protection and relevant regulations, be able to correctly command and supervise the correct operation of protection according to the regulations, and accurately master the switching on and off of relay protection of various equipment in the power, especially the switching on and off of power directional elements, reclosing, standby automatic switching and other devices of 35kV line. The preventive measures taken are to establish relay protection archives and scheduling shift handover record books

after the substation is unattended, the adjustment of microcomputer protection setting value and the change of operation mode are generally completed by the dispatcher and supervisor on duty (if the supervisor can't perform it, then the operation team will send personnel to operate on site). In order to nip the problem in the bud, I formulated the relay protection setting value management measures, established the relay protection setting value management register, and the relay protection full-time person issued the relay protection setting value notice to the dispatching team, monitoring team or operation team for execution. The dispatcher issued the dispatching order ticket to the supervisor or operation team operator to adjust the protection setting value according to the requirements of the setting value notice. After the execution, After the executor signs on the relay protection setting value notice, indicating the executor (generally two or more), the execution time, the description of the execution situation, and seals the executed seal, the dispatcher makes relevant records, replies to the relay protection full-time person, and then the relay protection full-time person distributes the executed relay protection setting value notice to the relevant teams for common compliance and implementation. At the same time, complete the registration procedures. The dispatching team shall establish relay protection setting value notice account, relay protection setting value modification record book account and microcomputer file management

3. Dispatching operation

3.1 dispatching operation monitoring system

Yangzhong power supply company took the lead in realizing unattended substation in 1996, and realized unattended substation in 1998. Remote control, remote adjustment, signal reset and other operations are commanded by the dispatcher on duty, operated by the supervisor, and unattended. In order to ensure the correct operation of the supervisor, the dispatching operation monitoring system is implemented at the dispatching end. The dispatcher on duty sends the dispatching order to the supervisor. The supervisor fills in the operation ticket according to the contents of the dispatching order, calls out the corresponding substation screen for remote control presetting, enters a switch number of a substation, and sends the remote control to 43.36% of the dispatcher on duty worldwide after being switched on or off, The dispatcher on duty inputs the same switch number and the name of the supervisor of the substation, and sends it to the supervisor after confirming the permission. The supervisor can carry out remote control after receiving the confirmation signal. After the implementation of the project, misoperation accidents have been effectively eliminated

3.210kv tie line and hand-held switch line the content of this meeting is Fengfu road

10kV tie line and hand-held switch line connecting the two substations. Due to the existence of double ended power supply, the dispatcher should accurately grasp the operation mode of the tie line and hand-held switch line, the status of the tie line tie switch and hand-held switch porous ceramsite, etc, Otherwise, serious accidents of power transmission with live grounding wire or grounding wire are likely to occur during operation and maintenance. With the requirements of power supply reliability index, 10kV tie switch and hand-held switch are widely used, and the safety control of 10kV tie line and hand-held switch line is very important. The preventive measures taken are to establish the status files of tie lines, hand-in-hand lines and the operation of tie switches and hand-in-hand switches, and establish a real-time simulation diagram screen at the dispatching end to display the operation status of tie lines and hand-in-hand lines

3.3 multiple working teams of the same equipment work at the same time

in order to reduce repeated power outages, there are often multiple teams working together, such as lines, substations, power supply stations, power distribution, etc. because there are multiple working teams working on the same equipment, the equipment can be put into service only after all working teams are finished. The safety control point is that when a team finishes its work before other teams, the dispatcher should remember not to put the equipment back into service. The preventive measures taken are to indicate multiple work shifts on the operation ticket, and use a safety warning to remind the blackboard to indicate the work of multiple work shifts. When the work of team a is completed and reported to be completed, mark team a off the blackboard, wipe it off after all the work shifts are completed, and return the equipment to service

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