The grid-connected solar photovoltaic power station is mainly composed of photovoltaic modules, photovoltaic brackets, solar inverters, grid-connected distribution boxes, cables and electricity meters.
1. Maintenance of components and brackets
1. The surface of photovoltaic modules should be kept clean. Dry or damp soft and clean cloth should be used to wipe photovoltaic modules. It is strictly forbidden to use corrosive solvents or hard objects to wipe photovoltaic modules. PV modules should be cleaned when the irradiance is lower than 200W/㎡, and it is not advisable to use liquids with a large temperature difference from the modules to clean the modules.
2. Photovoltaic modules should be checked regularly. If the following problems are found, the photovoltaic modules should be adjusted or replaced immediately.
Photovoltaic modules have broken glass, scorched backplanes, and obvious color changes;
There are air bubbles in the photovoltaic module that form a communication channel with the edge of the module or any circuit;
The junction box of photovoltaic modules is deformed, twisted, cracked or burned, and the terminals cannot be in good contact.
3. The live warning signs on the photovoltaic modules shall not be lost.
4. For photovoltaic modules using metal frame, the frame and bracket should be well combined, the contact resistance between the two should not be greater than 4Ω, and the frame must be firmly grounded.
5. When working without shadows, under the condition that the solar irradiance is more than 500W/㎡ and the wind speed is not more than 2m/s, the temperature difference of the outer surface of the same photovoltaic module (the area directly above the battery) should be less than 20℃. Photovoltaic power plants with an installed capacity greater than 50kWp should be equipped with infrared thermal imaging cameras to detect temperature differences 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 should not exceed 5%.
7. All bolts, welds and bracket connections of the bracket should be firm and reliable, and the anti-corrosion coating on the surface should not crack and fall off, otherwise it should not be brushed in time.
Second, the maintenance of solar inverter
1. The inverter structure and electrical connection should be kept intact, there should be no corrosion, dust accumulation, etc., the heat dissipation environment should be good, and there should be no large vibration and abnormal noise when the inverter is running.
2. The warning signs on the inverter should be intact and undamaged.
3. The cooling fans of the modules, reactors and transformers in the inverter should be normal to start and stop automatically according to the temperature. The cooling fans should not have large vibration and abnormal noise during operation.
4. Disconnect the circuit breaker on the AC output side (grid side) once regularly, and the inverter should immediately stop feeding power to the grid.
5. If the temperature of the DC bus capacitor in the inverter is too high or exceeds the service life, it should be replaced in time.
How to do correct maintenance and maintenance after installing photovoltaic power station
How to do correct maintenance and maintenance after installing photovoltaic power station
3. Maintenance of grid-connected distribution box
1. The distribution box must not be deformed, corroded, leaked, or deposited. The safety warning signs on the outer surface of the box should be intact and unbroken, and the waterproof lock on the box should be flexible to open.
2. The terminals in the distribution box should not be loose or corroded.
3. The insulation resistance of the positive pole to the ground and the negative pole to the ground of the output bus should be greater than 2 megohms.
4. The connection between the DC input interface of the distribution box and the combiner box should be stable and reliable.
5. The connection between the DC output of the distribution box and the DC input of the grid-connected host should be stable and reliable.
6. The action of the DC circuit breaker of the distribution box should be flexible, and the performance should be stable and reliable.
7. The lightning arrester configured on the bus output side should be effective.
4. Check the connection cable and grounding between equipments
1. The cable should not run under overload, and the lead package of the cable should not expand or crack.
2. The parts of the cables entering and leaving the equipment should be well sealed, and there should be no holes with a diameter greater than 10mm, otherwise they should be blocked with fireproof mud walls.
3. In the place where the cable has too much pressure and tension on the equipment shell, the supporting point of the cable should be intact.
4. There should be no perforations, cracks and significant unevenness at the mouth of the cable protection steel pipe, the inner wall should be smooth, the metal cable pipe should not be severely corroded, and there should be no burrs, hard objects, and garbage. If there are burrs, use the cable after filing. The jacket is wrapped and tied.
5. The accumulations and garbage in the outdoor cable well should be cleaned up in time. If the cable sheath is damaged, it should be dealt with.
6. When checking the open trench of indoor cables, it is necessary to prevent damage to the cable and ensure that the bracket is grounded and the heat dissipation in the trench is good.
7. The stakes along the direct buried cable line should be intact, and the ground near the path should not be excavated to ensure that no heavy objects, building materials and temporary facilities are stacked on the ground along the path, and no corrosive substances are discharged to ensure that the outdoor exposed ground cable protection facilities are intact.
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, ensure that the bracket in the trench should be firm, whether there is corrosion or looseness, and the sheath and armor of the armored cable should not be seriously damaged. Rust.
9. For multiple cables laid in parallel, the current distribution and the temperature of the cable sheath should be checked to prevent the cables from burning out the connection points due to poor contact.
10. Ensure that the cable terminal is well grounded, the insulating sleeve is intact, clean, and has no traces of flashover discharge, and ensure that the color of the cable should be obvious. During maintenance, insulating gloves must be worn, and the operating tools used are produced by regular manufacturers.
11. The equipment room must be kept clean, dry and ventilated; flammable and explosive items cannot be allowed to be placed in the equipment room.
12. Non-staff cannot be allowed to operate the instrument, open the instrument, modify the instrument parameters, etc.