Main dangerous points and control measures of swit

The main dangerous points and control measures of switching operation in substation operation

switching operation in substation refers to a series of orderly operations of electrical equipment or power system from one state to another, and from one operation mode to another, which is one of the key and difficult tasks in substation operation. Due to the different personal experience and focus of the on-site operators, the results are also different. At the same time, different operation modes of electricity, different main connections of substations, different configurations of relay protection and automatic devices, and different operation tasks will also affect each specific step of switching operation. Therefore, for different typical operations, analyzing their dangerous points, that is, the important links that are easy to cause misoperation, and mastering their correct operation methods and steps, have a very practical guiding role in preventing the occurrence of misoperation accidents.

1 main contents of preparation work before operation

(1) reasonably arrange operators according to the workload of power outage plan, and the division of work of receiver and recorder should be clear

through the "double integral" system (2) safety tools, instruments, grounding wires, fences, signboards are complete and sufficient, lighting and communication tools are normal, recording can be used, and tapes are sufficient

(3) analyze the impact of the change of operation mode on the station, and check that the safety measures issued by the work ticket comply with the regulations and site requirements

(4) check the way and order of issuing orders with the dispatcher, and prepare the operation ticket in advance. Check the protection setting value after changing the operation mode. If it is changed during operation, arrange cooperation personnel

(5) when the receiver conveys the contents of the order to the operator, it should explain whether it is an itemized order or a comprehensive order, so as to avoid operating the itemized order according to the comprehensive order

(6) the operator and supervisor must be clear about the scope and content of operation

(7) before operation, it is necessary to check the primary system diagram and find out the conditions of primary and secondary equipment related to operation

(8) when the repair of biological materials such as pla+pc and soybean foamed polyurethane is completed, the equipment status (including primary and secondary equipment) should be the same as that at the beginning of the work. If it is different, the maintenance personnel should explain the reasons

(9) it is necessary to strictly perform the work completion procedures, and the personnel on duty should go to the site to clarify some standards, which is the first time in the world; 3. The standard content is scientific and fair, so as to check whether there is any change in the equipment, such as the position and status of switches, knife switches, ground knives, ground wires, pressing plates, and fuses

(10) according to the operation task or the acceptance plan after equipment maintenance and the start-up plan of new equipment, the operator should correctly fill in the operation ticket, and the guardian and the person in charge on site should review and sign it to ensure that the operation ticket is correct

2 key points and key processes in the operation process

(1) clarify the overall requirements of the operation. During the operation, adhere to the ticket recitation system, operate according to the ticket, tick items one by one, and do not skip items. It is not allowed to joke or spread something irrelevant to the operation, so as not to distract the operator's attention; Do not leave the operation site midway to prevent single person operation or wrong interval; Do not unlock at will to prevent misoperation caused by forced unlocking

(2) the on/off of the protective pressing plate should be accurate and reliable. Because the power supply backup automatic switching board, main transformer mutual jump, bus differential, failure, low cycle and other protection boards are often not in the interval of power failure, but also closely related to the operation task, special attention should be paid to and do not forget

(3) the grounding wire sent to the grounding point in advance shall not be placed randomly, but can only be placed in the interval to be operated, so as to prevent malignant misoperation or personal accident of live grounding wire; The operating appliances shall not be placed in the wrong interval, which will cause misoperation such as entering the live interval by mistake or breaking and closing the switch by mistake; Before installing the grounding wire on the 10 kV double power line, the power inspection must be careful to prevent people from being injured by mistake; If the safety measures need to be changed during the test, such as adding or removing the ground wire, it must be operated by the operator, use the anti misoperation lock, and make records

(4) focus on preventing the grounding knife switch from being closed by mistake, such as the grounding knife switch on the bus side during the maintenance of voltage transformer. It is necessary to know the position of the grounding knife switch and the grounding range after closing, especially if the bus has multiple grounding points, which group to use must be clear. The grounding of busbar and voltage transformer shall be distinguished, and attention shall be paid to the setting and restoration of temporary changed safety measures in the test work

(5) remedial measures should be taken for devices that are difficult to verify electricity due to design reasons to prevent grounding wires from being hung on power

(6) attention should be paid to voltage switching: first, those that need to be switched must be switched, such as low cycle, distance, bus differential protection, etc; Second, those that should not be switched shall not be switched. For example, when the high-voltage side of the voltage transformer has been powered off, the low-voltage side shall not be powered back. For the primary disconnection operation, the secondary shall not be paralleled

(7) find out the parts that may be powered back or live, and take preventive measures, such as double power line knife switch, used transformer, voltage transformer, etc

(8) prevent static electricity from injuring people. For example, the fuse fusing points of capacitors equipped with fuses, cable outgoing lines and other equipment that generate static electricity must be discharged separately

(it accounted for 76% of the output of 3-yuan materials by model in 2016. 9) pay attention to whether the plug of the trolley switch is inserted and whether the insertion depth is sufficient during power transmission operation

(10) when switching the bus, the control fuse of the bus coupler switch must be removed