Do a good job in daily maintenance and build a high-quality photovoltaic power station

Photovoltaic power generation is not only green and environmentally friendly, but also conforms to the concept of low-carbon life. It can also make better use of the earth's renewable energy to protect the earth. However, in normal use, it is also necessary to perform dimension This can not only ensure the stability of power generation, but also ensure the service life and even extend the service life. How to maintain and manage photovoltaic power plants?, Maintenance of photovoltaic power station To ensure 25 years of operation. Today, we will talk about how to maintain photovoltaic power stations from eight aspects, which are applicable to distributed and centralized photovoltaic power stations.

Maintenance of components and supports

(1) The surface of the PV module shall be kept clean. Dry or wet soft and clean cloth shall be used to wipe the PV module. It is strictly prohibited to use corrosive solvents or hard objects to wipe the PV module.The PV module shall be cleaned when the irradiance is lower than 200W/㎡, and the liquid with large temperature difference from the module shall not be used to clean the module.

(2) PV modules shall be inspected regularly. If the following problems are found, the PV modules shall be adjusted or replaced immediately.Photovoltaic modules have broken glass, scorched backplane and obvious color change;There are bubbles in the photovoltaic module that form a communication channel with the edge of the module or any circuit;The junction box of the photovoltaic module is deformed, twisted, cracked or burnt, and the terminal blocks cannot contact well.

(3) The live warning signs on the PV modules must not be lost.

(4) For PV modules with metal frame, the frame and support shall be well combined, the contact resistance between them shall not be greater than 4 Ω, and the frame must be firmly grounded.

(5) When working under the condition of no shade, when the solar irradiance is above 500W/㎡ and the wind speed is not greater than 2m/s, the external surface of the same PV module (directly above the batteryArea) Temperature difference shall be less than 20 ℃. The photovoltaic power station with an installed capacity greater than 50kWp shall be equipped with an infrared thermal imager to detect the temperature difference on the outer surface of photovoltaic modules.

(6) Use a DC clamp type ammeter to measure the input current of each PV module string connected to the same DC combiner box under the condition that the solar radiation intensity is basically the same, and the deviation shall not beMore than 5%.

(7) All bolts, welds and supports of the support shall be connected firmly and reliably, and the anti-corrosion coating on the surface shall not crack or fall off, otherwise, it shall be brushed in time.

Maintenance of combiner box

(1) The DC combiner box shall be free of deformation, corrosion, water leakage and ash accumulation. The safety warning signs on the external surface of the box shall be complete and free of damage. The waterproof lock on the box shall be flexible to open and close。

(2) Each terminal in the DC combiner box shall be free from looseness and corrosion.

(3) The specification of the high-voltage DC fuse in the DC combiner box shall meet the design requirements.

(4) The insulation resistance of positive pole to ground and negative pole to ground of DC output bus shall be greater than 2 megohms.

(5) The breaking function of the DC circuit breaker equipped at the DC output bus end shall be flexible and reliable.

(6) Lightning arrester in DC combiner box shall be effective.

Maintenance of DC distribution cabinet

(1) The DC distribution cabinet shall be free of deformation, corrosion, water leakage and dust accumulation. The safety warning signs on the external surface of the box shall be complete and free of damage. The waterproof lock on the box shall be flexible to open。

(2) Each wiring terminal in the DC distribution cabinet shall be free from looseness and corrosion.

(3) The insulation resistance of positive pole to ground and negative pole to ground of DC output bus shall be greater than 2 megohms.

(4) The connection between DC input interface of DC distribution cabinet and combiner box shall be stable and reliable.

(5) The connection between DC output of DC distribution cabinet and DC input of grid connected host shall be stable and reliable.

(6) The DC circuit breaker of the DC distribution cabinet shall operate flexibly and its performance shall be stable and reliable.

(7) The lightning arrester configured at the output side of DC bus shall be effective.

Maintenance of inverter

(1) The structure and electrical connection of the inverter shall be complete, free of rust, dust, etc. The cooling environment shall be good, and the inverter shall be free from large vibration and abnormal noise during operation Sound.

(2) The warning signs on the inverter shall be complete and undamaged.

(3) The cooling fan of the module, reactor and transformer in the inverter shall start and stop automatically according to the temperature, and the cooling fan shall be free from large vibration and abnormality during operationIn case of abnormal noise, power off for inspection.

(4) Regularly disconnect the circuit breaker at the AC output side (grid side) once, and the inverter shall immediately stop feeding power to the grid.

(5) If the DC bus capacitor temperature in the inverter is too high or exceeds the service life, it shall be replaced in time.

Maintenance of AC distribution cabinet

(1) Ensure that the metal frame of the power distribution cabinet is well connected with the foundation section steel with galvanized bolts, and the anti loose parts are complete.

(2) The identification devices indicating the number, name or operating position of the controlled equipment in the distribution cabinet shall be complete, and the number shall be clear and neat.

(3) Bus joints shall be tightly connected without deformation, discharge blackening trace, loose and damaged insulation, and rusty fastening bolts.

(4) The handcart and withdrawable complete set of power distribution cabinet shall be flexible in pushing and pulling without jamming and collision. The center line of the moving and stationary contacts shall be consistent with that of the stationary contacts, and the contacts shall be in close contact.

(5) The switch and main contact in the power distribution cabinet shall be free of burning traces, the arc extinguishing shield shall be free of burning black and damage, all wiring screws shall be fastened, and the dust in the cabinet shall be cleaned.

(6) Take each separate cabinet out of the drawer and fasten each terminal. Check the installation and wiring of current transformer, ammeter and watt hour meter. The handle operating mechanism shall be flexible and reliable Tighten the incoming and outgoing lines of the circuit breaker, and clean the dust in the switch cabinet and at the outgoing lines behind the power distribution cabinet.

(7) The heat dissipation of the heating objects of the low-voltage electrical apparatus shall be good, the switching pressing plate shall be removed well, and the signal lamps, buttons, light plates, bells, flashlights, emergency bells, etc. of the signal circuit shall be in good condition The signal display shall be accurate.

(8) Check the insulation resistance between lines and between lines to ground of lines between cabinets, screens, desks, boxes and panels. The feeder line must be greater than 0.5M Ω, and the secondary circuit must be greater than 1M Ω. 

Transformer maintenance

(1) The thermometer of the transformer shall be intact, the oil temperature shall be normal, the oil level of the oil conservator shall correspond to the ambient temperature, and there shall be no oil leakage or seepage at all parts. Load size and cooling of each transformer

The conditions and seasons may be different. The transformer in operation cannot be based on the fact that the oil temperature of the upper layer does not exceed the allowable value. It should also be based on the previous operating experience and the previous Oil temperature comparison of.

(2) The oil level of the casing shall be normal, and the outside of the casing shall be free of damage cracks, serious oil contamination, discharge marks and other abnormal phenomena. The oil quality shall be transparent and slightly yellow, which can be judged The quality of the oil. The oil level shall meet the standard line of surrounding temperature. If the oil level is too low, check whether the transformer leaks oil. If the oil level is too high, check the use of the cooling device There is an internal fault.

(3) The sound of the transformer shall be normal, and there shall be uniform buzzing electromagnetic sound during normal operation. If the sound is abnormal, carefully check it, make a correct judgment and deal with it immediately。

(4) The transformer leads shall be free of broken strands, the joints shall be free of overheating discoloration or temperature indicator melting (discoloration), the respirators shall be in good condition, and the discoloration of silicone rubber shall not exceed 3/4.

(5) The tapping position and power supply indication of the excitation voltage regulating tap changer shall be normal, there shall be no gas in the gas relay, and the transformer shell and iron core shall be well grounded.

(6) In severe weather, special inspection shall be focused. In case of strong wind, check whether the lead wire swings violently, whether the sag is sufficient, and whether there are sundries at the transformer top cover and bushing lead wire, In heavy snow, all contacts shall not melt or discharge immediately after falling snow. In foggy days, whether there is spark discharge in each part.

Maintenance of cables

(1) The cable shall not operate under overload, and the lead package of the cable shall not expand or crack.

(2) The parts where the cables enter and exit the equipment shall be sealed well, and there shall be no holes with a diameter greater than 10mm, otherwise, the fireproof mud wall shall be used for sealing.

(3) At the position where the pressure and tension of the cable on the equipment shell are too large, the supporting point of the cable shall be intact.

(4) The steel pipe mouth for cable protection shall be free of perforation, cracks and obvious unevenness, the inner wall shall be smooth, the metal cable pipe shall be free of serious corrosion, burrs, hard objects and garbage If there is burr, wrap it with cable jacket after filing and fasten it.

(5) The accumulation and garbage in the outdoor cable well shall be cleaned in time. If the cable skin is damaged, it shall be treated.

(6) When checking the indoor cable open trench, it is necessary to prevent damage to the cable and ensure that the support is grounded and the heat dissipation in the trench is good.

(7) The stakes along the direct buried cable route shall be intact, and the ground near the route shall not be excavated, so as to ensure that there are no heavy objects, building materials, temporary facilities and corrosives on the ground along the route Discharge the water to ensure that the protection facilities of the exposed ground cables in the room are in good condition.

(8) Ensure that the cover plate of the cable trench or cable well is intact, there should be no water or debris in the trench, the support in the trench should be firm, free of rust and looseness, and the outside of the armored cable The leather and armor shall not be severely rusted.

(9) For multiple cables laid in parallel, check the current distribution and the temperature of the cable sheath to prevent the cable from burning the connection point due to poor contact.

(10) Ensure that the cable terminal is well grounded, the insulating sleeve is intact, clean and free of flashover discharge traces, and the cable phase color should be obvious.

Extreme weather maintenance

(1) In case of rain tripping, it may be that the connector is not tight. In case of such a situation, it must be handled after rain and sunshine. Wrap the connector with insulating tape, and then observe whether

Trip. If the trip continues to occur, report to the maintenance center or the local electricity management station.

(2) In thunderstorm days, the air switch below the meter should be turned off to prevent damage to electrical equipment. Turn on the switch after the thunderstorm.