Analyzing the dangerous points in dispatching operation and taking corresponding control measures against the dangerous factors and habitual violations in work will help to enhance the safety risk awareness of dispatchers and reduce the possibility of economic losses and accidents.
Keywords: scheduling operation; Danger point; Control measure
Dispatching operation includes the monitoring, operation, operation and command of the power grid, which shoulders the important responsibility of safe, stable and economic operation of the power grid and ensuring industrial and agricultural production and people's living electricity consumption. By analyzing the dangerous points in the dispatching operation, effective control measures are taken to enhance the dispatcher's safety awareness, put an end to habitual violations and realize the "controllable, controllable and controllable" safety production.
1 analysis of dangerous points in operation mode and control measures
1. 1 dangerous point for receiving maintenance application
The content of the job application is unclear. For example, the name of the maintenance equipment is inaccurate, and the equipment status requirements and power outage range are not clear.
Control measures: fill in the work application form, and after accepting the maintenance application form, check the name of the maintenance equipment and the required power outage range with the applicant; Check the wiring mode and running state of the equipment, and whether the power outage range meets the maintenance needs; Standardize the use of dual numbering of equipment; Implement the review procedure.
1.2 Operation mode reverts to dangerous point.
Control measures: strengthening modal analysis; Avoid the bus stop operation mode at any voltage level of 1 10 kV or above in the substation when N-I fails; Unit maintenance and power grid equipment maintenance should be communicated and coordinated, and safety verification should be done to prevent local power grids from being blocked in sending or receiving electricity; Understand the change of primary mode and its influence and requirements on secondary mode; Strictly implement the principle of secondary setting, and if the time cannot be set according to the principle, it shall be approved by the chief engineer; Do a good job in load forecasting, understand the power transmission plan, and correctly reflect the trend of the power grid.
1.3 new equipment startup scheme danger point
Control measures: go deep into the site to familiarize yourself with the equipment and related drawings, check the name and number of the equipment, define the jurisdiction of the equipment, and determine the operation mode and main transformer tap. The production unit is required to put forward a trial operation plan, including the start-up of transmission procedures, trial operation projects, connection loads, requirements for power grids, etc. Understand the nuclear phase and test requirements of equipment.
1.4 temporary inspection of dangerous points for power grid equipment
Control measures: First of all, according to the actual situation on site, temporary inspection can only be approved when the equipment really needs temporary inspection. For the temporary inspection of equipment, it must be stopped immediately, and the relevant leaders can be asked to stop immediately without notice. However, when other safety measures need to be taken after the equipment stops, an operation ticket must be filled in. If the equipment does not need to be stopped immediately, it must be informed of its normal operation.
2 Analysis of dangerous points in dispatching operation and control measures
2. 1 Repair work application reply to dangerous point
The work application form is not standardized. If the equipment applied for in the work ticket is inconsistent with the work content and requirements; The reply method is inconsistent with the job application.
Control measures: the work contents and working hours filled in the working ticket should be coordinated, and the work requirements should be clear; Application equipment shall use dual naming numbers; Job seekers are approved and announced by the unit and reported to the dispatch for the record; The reply mode should be consistent with the reply of the superior dispatching department; Fill in the special instructions clearly.
2.2 write scheduling operation ticket dangerous point
The "four comparisons" were not made when the ticket was issued, and the impact of equipment power failure on the system and related equipment was not considered.
Control measures: the drafting of dispatching operation ticket should be "two clear" and "four control": that is, the maintenance application and power grid mode arrangement should be clear, and the operation tasks should be clear; Check the work application form, application form and operation precautions, check the status of field equipment against the simulation disk, and check the operation ticket and operation record.
2.3 review operation ticket dangerous points
The dispatcher's audit is not careful, the operation content of the operation ticket is unreasonable, the mode adjustment is unreasonable, the protection is not adjusted as required, and the influence of the power outage range is not considered.
Control measures: check the primary system, including whether the actual positions of circuit breakers and disconnectors in the system have grounding wires, the status of relay protection and automatic devices, and correctly predict the power flow and voltage changes of the system in operation and the possible impact on the system. Important operations need to be calculated by dispatching power flow. According to the actual situation of the system, the operation ticket and the necessity and correctness of each operation in the operation ticket need to be audited word by word.
2.4 scheduling operation dangerous points
Disorder and scheduling; The dispatcher's spirit and environment are not good when operating, and the dangerous point analysis is not done well before operation; Other agencies have businesses that need to be coordinated; Do not use unified scheduling terms and operation terms.
Control measures: the dispatcher maintains a good mental state; During the peak load period, the operation time should be staggered as far as possible, and no accidents will occur in other parts of the system; Dispatchers should master the emergency plan of power grid accidents, do a good job in analyzing the dangerous points on duty, and make accident prediction in time according to the power grid situation; Preoperative preparation should be sufficient and the purpose of operation should be clear; In strict accordance with the order of operation tickets, when scheduling and cooperating at intervals, the state of the system and equipment should be clearly handed over and operated in accordance with the principles stipulated in the regulations; In addition, unified scheduling terms and operation terms should be used, the instructions issued by the sender should be accurate and clear, the dual names of equipment should be used, and the operation should be supervised; When an accident occurs, the operation should be stopped immediately, and the operation can only be continued after the situation is clarified and the accident treatment is completed.
2.5 operational risk points of multi-power community
Control measures: strengthen the user management of self-provided generators. Cut off all other power supplies, strengthen the management of multi-power users, and formulate measures to prevent low-voltage lines from sending electricity backwards.
2.6 Dangerous points of closed-loop inverter power supply operation
Control measures: there should be a nuclear phase at the closing point; Load forecasting, using dispatching automation to calculate power flow; Due to the need of operation mode, several sets of protection setting values can be set for individual circuit breakers, and the setting values should be selected and put into operation; Operate in strict accordance with the sequence, so as to prevent misoperation.
3 Analysis and control measures of dangerous points in dispatching accident treatment
3. 1 information collection of accident danger points
Control measures: The dispatcher should collect accident information comprehensively. Before failing to fully understand the situation in time, he should first briefly understand the accident situation, analyze the impact on the system in time, further understand the accident situation according to the system situation, and consult relevant information.
3.2 Accident Analysis and Danger Point Judgment
The dispatcher's quality can't meet the requirements; Did not correctly understand the scope and extent of the accident, did not understand the equipment within the jurisdiction of the dispatch.
Control measures: the dispatcher should have good psychological quality and professional and technical quality, and have the ability to deal with accidents; The dispatcher should accurately grasp the operation mode of the power grid at that time, clearly understand the action state of field equipment, protection and safety automatic devices, and master the accident handling principles of voltage, frequency abnormality, system vibration and other faults stipulated in the dispatching regulations; Accurately grasp the equipment within the jurisdiction of dispatching at all levels, report relevant dispatching in time, and assist and cooperate with accident investigation and handling as needed.
3.3 Accident handling dangerous points
Failure to accurately grasp the operation mode of power grid; Failure to abide by the principle of accident handling, which leads to the expansion of the accident due to mistakes in accident handling.
Control measures: according to the obtained information and analysis, handle the accident according to the principle, grasp the change of power grid operation mode caused by accident handling, and consider and pay attention to the trend, voltage change and equipment limitation during accident handling; Accident treatment should prevent misjudgment caused by poor contact, unknown situation or inaccurate on-site report, deal with abnormal system frequency and voltage in time according to regulations, prevent overload tripping, ground wire closing, non-synchronous juxtaposition, power grid stability damage, switch tripping times within the allowable range, and prevent protection misoperation.
3.4 Operation mode adjustment danger point
Control measures: adjust the system operation mode in time according to the power grid operation mode and stability principle after accident treatment.
3.5 Fault isolation and dangerous point treatment
Control measures: The dispatcher doesn't know enough about the power grid structure, operation mode, power flow data, protection configuration and equipment parameters. When something happens, he immediately asks for instructions, delays the work, and quickly isolates the fault points in strict accordance with the principle of accident handling, paying special attention to the recovery and power transmission of power-off equipment.
Analysis and control measures of dangerous points in dispatching automation
4. 1 scheduling monitoring screen danger point
Data monitoring is not in place; Telemetry and remote communication information collection is inaccurate.
Control measures: the dispatching monitoring screen should not just wait for the alarm prompt, but should actively check the operation information of the substation, especially the consistency check of telemetry data and telemetry signals, such as whether the switch position and measurement, the main transformer tap position and bus voltage data are consistent; According to the power flow calculation, check the accuracy of the data and inform the automation task force to deal with it in time.
4.2 Remote operation of dangerous points
Control measures: all operations should be monitored and misoperation prevention measures, and two people are usually arranged on duty, which is to consider this requirement.
4.3 Dispatching automation misoperation danger points
The number of remote control points is set incorrectly, and the remote control objects and attributes are selected incorrectly. Causing misoperation.
Control measures: ensure the correctness of remote control points, and conduct on-site remote control test at the end of automation transformation acceptance to ensure correctness; When conducting remote control operation, carefully check the object and nature of remote control to prevent accidental remote control.
5 protection setting work dangerous points and control measures
5. 1 list of dangerous points with fixed values
The fixed value list does not meet the requirements of field equipment; Non-standard, unclear and incomplete, such as: the setting list does not meet the TV, TA ratio and secondary equipment wiring; The serial number, execution date, equipment name, protection device model and TA/TV ratio for protection are not standardized.
Control measures: the change of setting list shall be made according to setting notice and dispatching order, and communicate with setting calculation personnel in time when in doubt; When the dispatcher receives the setting list, he should check whether the setting list is standardized, clear, complete and meets the requirements.
5.2 relay protection and automatic device fixed value calculation of dangerous points
Control measures: Setting calculation personnel shall ensure that relevant parameter data are correct, be familiar with relevant drawings and field equipment, carefully calculate the fixed value, and conduct audit in strict accordance with regulations to ensure accurate calculation of the fixed value.
5.3 Protective arrangement of dangerous points
The arrangement of protection methods is unreasonable.
Control measures: master the relevant provisions of protection operation, be familiar with the operation mode and situation of power grid, and master the protection configuration and setting coordination.
6 concluding remarks
Power grid dispatching is a rigorous, meticulous and persistent work, and each link has many dangerous points. Only by persistently analyzing dangerous points and taking effective control measures can economic losses and the possibility of accidents be reduced.
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