Photovoltaic power station safety production management

Two votes three systems – “three systems” specification and implementation

Two votes three systems - "three systems" specification and implementation

The “three systems” are the shift system, the patrol inspection system, and the equipment regular test switching system. The shift system is one of the basic management systems in power safety production. It refers to an important measure for operators to clearly hand over the responsibilities of both parties in the operation positions between work and get off work, and to ensure safe production. Patrol inspection refers to an important system for production personnel to conduct a comprehensive inspection of important parts of production at regular and fixed points according to the specified time interval, master the situation, record data, find problems, eliminate hidden dangers, and ensure safe production. Periodic testing of equipment refers to the dynamic or static starting, transmission of running equipment or standby equipment to check the health level of running or standby equipment.

(1) Standard requirements for the handover system

  1. Overview of the shift system
    The shift handover is organized by the person in charge of the shift, the shift comes first and the shift comes later. The shift must be “five clear” and “three shifts”, and at the same time, “three handovers” and “five non-handovers” should be achieved.
    “Five Clears”: to clarify, to see clearly, to ask clearly, to find out, to point out.
    “Three shifts”: station shifts, on-site shifts, and physical shifts. “Three handovers”: oral handover, written handover, and on-site handover.

“Five No Pickups”: No pick up if the shift preparation work is not done (such as unclear records, unclear explanations, etc.); No pick up until important operations, equipment testing, and accident handling have not come to an end; No pick up if important items, tools, and data are lost ( Such as switch room, “five-proof” key; inspection, operation, maintenance tools, instruments, meters, etc.; operation log, “two tickets”, grounding wire registration, drawings, work records, technical data, etc.); Do not connect properly (dirty, chaotic, poor environmental sanitation); if the superior’s notice or order is not clear, or there are other situations that hinder the safe operation of the power station and no preventive measures are taken.

  1. Main procedures for handover
    (1) The main work of the shift.
    Before the shift, the shift staff should make various preparations for the shift according to their respective responsibilities. Mainly include: various inspections, equipment regular testing and switching work and operation work; a check on the operating status of the equipment under its jurisdiction; check the operation log, DCS parameters are normal; check safety tools, walkie-talkies, keys, and regulations. Spare parts, drawings, reports, etc. are complete and complete; carefully record the handover records of people, and the content is not omitted.

(2) On-site inspection of the shift.
The successors of each post shall conduct on-site equipment succession inspections in accordance with the inspection items, contents and requirements stipulated in the power station shift handover regulations. On-duty duty is mainly to check and check the operation log, work ticket, tools and keys and other public items during off-duty period. The on-duty person on duty shall explain the on-site work and abnormal situations that he has learned to the shift supervisor. The shift supervisor shall explain the safety precautions, work points, etc. to the shift staff.

(3) Pre-class meeting.
The shift supervisor briefly explained the on-site operation mode, abnormal situation, and main work progress to the shift staff.
(4) Post counterpart handover.
After the successor arrives at the post, the successor should take the initiative to verbalize the situation of the class to him. If the successor is unclear, he should take the initiative to make an inquiry, and the successor should answer patiently.
(5) After-class meeting.
After the shift is handed over, the team leader will organize a post-shift meeting. The main contents include checking the personnel on duty, confirming that they have been handed over, and summarizing and commenting on the completion of the work of the shift.

(2) Specifications for equipment patrol inspection

  1. Overview of the patrol inspection system
    Patrol inspection is an essential and important measure to grasp the health status of operating equipment, collect first-hand information on operation, discover equipment abnormalities in time, eliminate equipment hidden dangers, prevent equipment accidents, and maintain safe and economical operation of power generation equipment.

(1) Daily inspection.
Routine inspections refer to routine inspections carried out by power station operation and maintenance personnel according to the specified time, cycle, inspection route, inspection content and work standards.
(2) Special inspection.
Special inspection refers to the inspection of equipment under special circumstances, such as equipment characteristics, special operation methods, large changes in load, changes in natural conditions (cold wave, high temperature, typhoon, rainstorm, lightning strike), new equipment put into operation, and trial operation after equipment maintenance. , Equipment inspection in the event of equipment abnormality or accident and special requirements of the superior department.

  1. Basic requirements for patrol inspection work
    (1) Safety requirements.
    1) Inspection personnel must be trained and qualified in the “Electric Power Safety Work Regulations”, and have the ability to perform on-duty inspection work, and be reviewed and approved by the operation and maintenance management department. During the inspection work, it is necessary to strictly abide by the “Power Safety Work Regulations” and relevant safety management regulations, and be responsible for the accuracy of the inspection result information.

2) Inspection personnel must correctly wear personal protective equipment, such as work clothes, safety helmets, work shoes, etc., in accordance with the requirements of the Electric Power Safety Work Regulations.
3) According to the regulations of “Electrical Safety Work Regulations”, pay attention to maintaining a safe distance from live equipment (see Table 1), and do not move or cross safety barriers at will, and do not move signs at will.

Table 1-Safe distance from the human body when the equipment is not powered off
Table 1-Safe distance from the human body when the equipment is not powered off

4) When inspecting outdoor high-voltage equipment during thunderstorms, you must wear insulating shoes and keep away from lightning arresters and lightning rods.
5) When encountering extreme bad weather such as strong winds above level 6, sandstorms, thunderstorms, heavy fog, heavy snow, etc., outdoor equipment inspections are generally not carried out. When it is really necessary to inspect the equipment due to special circumstances, risk prevention and control must be carried out, and safety protection measures such as anti-falling, anti-falling, anti-collision, anti-object strike, anti-skid, anti-lightning and anti-electrical damage must be fully implemented.

(2) Management requirements.
1) The operation and maintenance personnel on duty must conduct daily patrol inspections of the equipment under their jurisdiction in accordance with the “Power Safety Work Regulations”, operation and maintenance regulations and related management regulations and requirements, and accurately grasp the operation status and existing problems of the equipment.

2) The inspection of photovoltaic equipment is generally carried out by two or more people. When one person must inspect alone, it should be approved by the person in charge of the duty on duty; the whole process of inspection should maintain smooth communication to facilitate timely reporting and contact.

3) Concentrate on the patrol inspection and do not do anything unrelated to it.
4) In special cases, according to the needs of the operation and maintenance of the inspection equipment, you can carry the necessary inspection tools, such as light test pen, temperature measuring gun, multimeter, clamp current meter, safety pliers, vise, sharp cone pliers, crimping pliers , Allen wrench, screwdriver, electrician’s knife, wrench, etc.
5) Equipment inspection should follow the “four determination principles”, namely “determined time (including cycle and frequency), determined route, determined content, and determined standard” to ensure the quality and effect of inspection.

6) Before the equipment inspection, it is necessary to carefully check the operation log, equipment defect record, grounding wire, grounding disconnector (or short circuit) installation record, and accurately grasp the system and equipment operation mode, maintenance operation and operation operation and other work arrangements. Be aware of it.

7) During the inspection process, if an emergency situation that seriously endangers personal and equipment safety is found, necessary measures should be taken immediately to avoid accidents in accordance with the regulations, and at the same time, it should be reported to the person in charge of duty immediately, and the person in charge of the duty should be unified. Under the command, handle exceptions, faults or accidents. If a general equipment defect is found, it shall be dealt with on-site with the consent and guidance of the person in charge on duty; if it cannot be dealt with on-site, the repair report process shall be followed according to the defect management regulations.

8) The normal standby equipment should be checked normally to ensure that the standby state is intact; the equipment in the maintenance state should focus on checking whether the safety measures have been kept in good condition and have not been changed without authorization.

9) After the inspection is completed, the situation of the inspection must be reported to the person in charge on duty in a timely manner. For the equipment defects found, according to the relevant regulations and requirements, make careful inspection records and defect registration.

10) In the following cases, the number of inspections should be appropriately increased and key inspections and monitoring should be carried out: ①The equipment has major defects or abnormalities, and it is temporarily impossible to stop the operation; ②The equipment that is newly put into operation, modified or repaired and put into trial operation; ③When the weather, temperature and other climatic changes are large, which may endanger the safe operation of the equipment; ④When the system operation mode and the conditions of the equipment operation change, which may endanger the safe operation of the equipment.

11) The equipment inspection should make inspection records in a timely manner. If necessary, it can take various forms such as recording parameters, on-site photography, instrument measurement, etc., to record the abnormal changes of the operating equipment in detail, so as to facilitate accurate analysis and timely processing of equipment abnormalities or defects.

  1. Equipment inspection content
    (1) Daily inspection.
    1) Outgoing line inspection. Main inspections: ①Whether there are signs of excavation in the cable line protection area, whether heavy objects and harmful chemicals are stacked; ②Whether the cable line markings are in good condition, whether the cable trench and cover are complete, whether the cable passages are tightly blocked, and whether the cable intermediate joints are firm. Whether the well has accumulated water; ③Whether there is overheating, oil seepage, discharge, flashover, arc climbing and scorching at the cable terminal; ④Whether the overhead line tower is normal; Whether the wires, cables and grounding devices are normal; ⑥ Whether there are trees or antennas around the overhead lines that endanger safe operation.

2) Outgoing line interval inspection. Main inspection: ①The position indication of circuit breaker, isolating switch and grounding switch is correct, whether the control circuit and energy storage of the circuit breaker are normal; ②Whether the insulating gas pressure meets the requirements of operation regulations, whether there is air leakage (SF6 gas and compressed air), leakage Oil (hydraulic oil and cable oil) phenomenon, etc.

3) The busbar interval is patrolled. Main inspections: ① Whether the foundation and structure are normal, whether the wires have broken strands, loose strands, or hanging debris; ② Whether the insulators have flashover and corona.
4) Interval inspection of main transformer. Main inspections: ① Whether the sound, temperature, temperature rise, oil color, and oil level of the main transformer are normal, the operation monitoring parameters are within the specified range, and there is no oil leakage or discharge phenomenon; ② High-voltage cable terminals, high-voltage bushings, insulating supports The circuit breaker and arrester are clean and intact, and there are no abnormal phenomena such as heat generation, discharge, and damage; ③ The pressure relief valve, safety air passage and explosion-proof membrane should be intact, and there should be no gas in the gas relay; @ Each control box, secondary terminal box, and mechanism box should be Closed tightly, no damp.

5) SVG interval inspection. Main inspections: ①The SVG incoming cabinet and the power cabinet are in good condition, the temperature is normal, the cooling fan is running well, the dust filter at the air inlet is not blocked, and the signal indicators are normal; ②The isolation switch, circuit breaker, arrester, reactor, power cabinet Running without exception.

6) Grounding variable interval inspection. Main inspection: ①The arrester is running normally, no noise, no cracks or damages in the porcelain, and the leakage current is normal; ②The appearance of the current and voltage transformers is intact, the connection lines are firm, and there is no abnormal vibration, overheating discharge, cracks or damages in the porcelain; ③ The appearance of the circuit breaker is normal, the opening and closing indication is correct, the control circuit and energy storage are normal; the insulating gas pressure gauge indicates normal; ④ The isolation switch supports the insulators to be clean and in good condition; The lead wire is not loose, and there is no burn and broken strands; the isolation switch body, connection and mechanical parts of the rotating shaft are not deformed, and all parts are well connected; the anti-misoperation locking device is good, and there is no damage; ⑤ The sound, temperature, and temperature rise of the grounding transformer are normal, and the high-voltage cable The terminal head, high-voltage bushing, insulating support, and arrester are in good condition, and the cooling fan is running normally; ⑥ The ceramic outer insulation surface of the arc suppression line is clean, and there is no crack, moisture, or discharge; No overheating; the oil-immersed arc suppression coil has no oil leakage, and the temperature and temperature rise meet the operating regulations.

7) Interval inspection of capacitor banks. Main inspection: ① There is no abnormal noise in the capacitor, no oil leakage or oil leakage from the drum wall, the temperature is normal, the capacitor room is well ventilated, the insulator of the capacitor pillar is clean and there is no crack discharge phenomenon; the grounding wire is firm; ② the supporting insulator of the disconnect switch is clean and intact; The contacts and contacts are in good contact, no heat generation, no deformation; no loose leads, burns and broken strands; the anti-mistake locking device is in good condition; ③ The arrester is not loose, the porcelain part is free of cracks and damage, the arrester runs without noise, and the action counter The seal is good, and the leakage current of the arrester is normal; ④ The current transformer support structure has no tilt deformation, and the base has no damage and cracks; the external insulation is intact and no damage, and there is no discharge phenomenon; no obvious noise, local overheating, and discharge phenomenon.

8) Station with variable interval inspection. Main inspections: ①The sound of the transformer is uniform, and the lead joints, cables, and busbars have no signs of heating; ②The control box, secondary terminal, and mechanism box are closed without moisture, and the temperature control device is working normally; ③The external surface of the dry-type transformer is free of dirt; The doors, windows and lighting of the transformer room are in good condition, the house does not leak water, and the temperature is within the normal range; ④ The oil temperature and color of the oil-immersed transformer are normal, and there is no oil leakage or oil leakage. High-voltage cable terminals, high-voltage bushings, and insulating supports The sub and arrester are clean and in good condition without discharge phenomenon.

9) Inspection of high-voltage switchgear. Main inspections: ① The switch status indication is consistent with the actual operating status; the energy storage of the switch operating mechanism is normal; the high-voltage cabinet has no abnormal sound and smell; the gas pressure of the SF6 circuit breaker is displayed normally; , current and other operating parameters are within the rated allowable range; ③ The foundation of the switch cabinet has not undergone significant settlement, and the cabinet body has not been deformed.

10) Secondary panel inspection. Main inspections: ① All protection and automatic devices are running normally, no protection action, abnormal alarm, and fault recorder is working normally; all protection connecting pieces are put in correctly; ② The wiring of each terminal block is firm and not loose, and the cabinet and device shell are grounded reliably; The position of the secondary air switch is correct; the signs are clear and correct.

11) AC system inspection. Main inspections: ① All panels, cabinets, dual power supply switching devices, drawer switches and other equipment of the electrical AC system are running normally, without abnormal discharge, overheating, and peculiar smell; ② The mechanical locking and electrical locking actions of each equipment are correct, and each switch is one or two The secondary plugs are in good contact; the signal indications are correct, the lighting in the cabinet is in good condition, and the signs and signs are clear and complete; ③ The dual power switch device is operating normally;

12) Inspection of box-type transformers. Main inspections: ①The sound, temperature, temperature rise, voltage and current of the transformer are normal; whether the oil level and pressure gauge of the transformer are in the normal range, and record the current data. ② There is no abnormality in the high-voltage load switch, cable terminal, high-voltage bushing, insulating support, and arrester, and there is no looseness, heat, and discharge of each connecting line; no oil injection or oil leakage in the pressure release valve. ③ There is no abnormal alarm or fault information in the measurement and control device, the live indicator and the indicators of each instrument are normal, the cooling fan is running normally, and the fire blocking is intact without falling off.

13) Inverter inspection. Main inspection: ① The inverter has no abnormal alarm or fault signal. ②The AC and DC power, voltage, current, and module temperature are within the normal range; the operation panel shows that there is no jamming, the AC and DC switches are not overheated or abnormal, and the components in each DC unit cabinet are not overheated or abnormal. ③The temperature of the module is normal, the ventilation filter is free of dust, and the cooling fan is running normally. ④ The inverter room is in good condition without water leakage, the box body is not cracked, the shell is well grounded, and the door locks are in good condition.

14) Inspection of the communication cabinets in the photovoltaic area. Main inspection: ① The communication management machine and photoelectric converter in the communication cabinet are running normally, and the data transmission is normal. ②The communication cabinet, internal lighting, incoming and outgoing cables, and optical cables are in good condition, and the AC and DC distribution boxes and branch switches are in good condition. 3 The UPS power supply works normally, and the battery has no abnormal conditions such as leakage, acid creep, deformation, loose connection, abnormal temperature, discoloration of positive and negative terminals, and corrosion.

15) Combiner box inspection. Main inspection: 0 The box body, box door, door lock, and sealing strip are in good condition, and there is no damage, water leakage, dust accumulation, and serious rust. 2. The circuit breakers, fuses, bases, wiring joints are firm and in good contact, and there is no abnormality such as damage, fuse, looseness, and overheating; the lightning protection module is not damaged or faulty. ③The signs of each branch are complete, clear and complete, the insulation of each cable is not damaged, and the holes are tightly sealed against fire. ④ The data acquisition device of the intelligent combiner box is running normally, and there is no abnormal situation such as black screen, blurred handwriting, garbled characters, etc., and the displayed current value is consistent with the monitoring background value.

16) String inspection. Main inspection: ① The components and brackets are free from inclination, falling off, corrosion, deformation, loose bolts, etc., the foundation is firm, and there is no cracking, collapse, inclination, or exposure to wind erosion. ②The glass and film on the surface of the module are not damaged, the frame is not deformed, the surface of the module is free from air bubbles, EVA delamination, water vapor, hot spots, snail patterns, lightning patterns and other abnormal conditions; the surface of the module is not blocked, and there is no serious dust accumulation. ③ There is no glue opening, bulging, air bubbles, discoloration, damage, breakdown, scorching, peeling, etc. on the backplane of the module, and there is no abnormality such as aging, heating, and burning in the junction box of the module. ④ There is no virtual connection of the DC cable connection plug; there is no detachment, virtual connection, heating and burning of the MC4 plug connected between the components. ⑤ The push-pull rod and bearing box of the string (tracking bracket) are not bent and deformed, and the pins are not broken or fallen off; the foundation of the driving device is not sag or damaged, and the driving motor has no oil leakage and cannot work normally; the operation of the rotary reducer is no different from normal operation. Noise, oil leakage, and inability to operate normally; the main rocker arm is not deformed, and the connecting pin is not broken or fallen off; the drive power supply is not faulty; the drive cable connection is free from virtual connection, breakage, and the protective sleeve is not damaged; gear machine and drive unit The connecting bolts are not loose, corroded, etc.

17) Lights out inspection of the collection station, booster station and switch station equipment. Main inspections: transformers, arc suppression coils, circuit breakers, isolating switches, busbars, arresters, voltage, current transformers, SVG, grounding transformers, station transformers, capacitors, high-voltage switchgear, high-voltage cable heads, leads and lighting equipment. ①Normal operation, no abnormal discharge and vibration sound; ②There is no flashover and arc creeping phenomenon in each insulator part; ③The dynamic and static contacts of circuit breakers, isolating switches, high-voltage cable heads and equipment connection parts are free of abnormal heat and peculiar smell , overheating, redness, discharge flashover and other abnormal phenomena.

18) Light-off inspection of the high-voltage room of the box-type transformer. Main inspection: There is no corona, discharge, overheating of joints and other phenomena in box change and cable head.

(2) Special inspection.
1) Special inspection after heavy snowfall.
Focus on checking the damage of outdoor equipment such as modules, supports, and overhead lines in the photovoltaic area by ice and snow pressure; the leakage of melted water damages the insulation of operating equipment, which may cause discharge and short-circuit accidents; according to the melting of snow, accurately determine the hot parts of the joints of operating equipment , it is convenient to deal with icing in time and eliminate potential safety hazards.

2) Special inspection during heavy fog.
Focus on checking the equipment’s external insulation, bushings, and insulators for fog flashing, creepage, discharge and sparking and other abnormal phenomena.
3) Special inspection during cold wave.
Focus on checking the freezing rain caused by the cold wave, the rain slamming down the power line, causing short-circuit accidents, etc.; the temperature drops sharply, and the oil level of the oil filling equipment is too low, and the equipment has no oil leakage.

4) Special inspection after thunderstorm.
Focus on checking the distribution box and cabinet for water leakage, equipment grounding and discharge; whether there is discharge or flashover in the external insulation of the equipment; whether the arrester operates; whether the grounding wire and row have burnt or discharge traces; ;Whether there is a lot of stagnant water in the cable trench and cable well.

5) Special inspection after strong wind.
Focus on checking the damage of components, brackets, outdoor lines, leads, switch room doors and windows, outdoor control boxes, distribution boxes, cabinet doors, etc. in the photovoltaic area, and check whether components, brackets, fixing bolts, and components are firm, and whether there is falling off, tilting, etc. Out-of-position, looseness, and loss; whether the lead swing is too large and there is a safety risk; whether the equipment and leads are hung with debris; whether the equipment foundation, pillar, frame, crack, loose, skewed, or collapsed; Whether the doors of the control box, power distribution box and terminal box are closed reliably and in good condition, etc.

6) Special inspection after hail.
Focus on checking whether the modules, supports, and overhead lines in the photovoltaic area are hit by hail, whether the external insulation of the equipment is damaged, whether there is a discharge flashover phenomenon, and whether the components are damaged.

  1. Equipment inspection and inspection route
    Different photovoltaic power plants have different inspection routes according to the actual situation, but the basic routes are similar, as follows:
    (1) Control room-relay room-35kV switch room-power distribution room-station transformer-SVG room-SVG transformer-grounding transformer.
    (2) Photovoltaic modules – combiner box – inverter – box transformer.
    (3) Booster station (main transformer – circuit breaker, control cabinet, isolating switch, transformer, arrester, busbar and other equipment) – external line.

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