What inspections should be done to your photovoltaic system on a regular basis?

It is very important to check the photovoltaic system regularly. We often see reports that many photovoltaic systems are damaged to varying degrees due to poor later maintenance and regular physical examination, which will bring more serious fault problems to the whole photovoltaic system. Here are the key inspection contents for you.

Inspection of photovoltaic support

The function of photovoltaic support in solar power system is to protect photovoltaic modules from being damaged by natural conditions such as strong wind and snow, which can withstand the gravity of photovoltaic modules for 25 years. The material of the solar panel supports systems mainly includes stainless steel and galvanized steel. Generally, it has good compression resistance, strong wind resistance and corrosion resistance.

01 stability check

The photovoltaic support is exposed to wind and rain for a long time outdoors, and the connector is easy to loosen due to various tensions. During physical examination, check that all bolts, welds and support connections should be firm and reliable, and check the stability of pv system components support. If the support bolts and nuts are loose, they should be firm in time.

02 Corrosion resistance inspection

According to the actual situation of the installation site, such as high temperature and humid operating environment, the metal support shall be regularly checked for corrosion, and the anti-corrosion coating on the support surface shall not crack or fall off, otherwise it shall be painted immediately.

03 tracking support

For the solar cell array support with polar axis automatic tracking system, regularly check whether the mechanical and electrical performance of the tracking system is normal.

Inspection of cables. AC and DC cables are generally concealed works in photovoltaic system. The cables will be laid through pipes or bridges. The inspection is slightly difficult, but it can not be ignored.

01 appearance inspection

The photovoltaic cables connected between modules shall be bound reliably without looseness and damage; The cable signboard shall be free from missing or damage. The identification handwriting of each string shall be clear and easy to identify. If it is damaged, it shall be replaced in time. For cables and terminal heads connected with overhead lines outdoors, check whether the terminal head is complete and whether the contact of outgoing line is heated and blackened.

02 seal inspection

The inlet and outlet lines of combiner boxes, bridges and other equipment shall be blocked well, and there shall be no holes with a diameter greater than 10mm, which shall be blocked with fire-proof mud.

03 cable integrity inspection

Ensure that the cable terminal is well grounded, and the insulating sleeve is intact, clean and free of flashover and discharge traces; Ensure that the phase color of the cable should be obvious; 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; The cable shall not operate under overload, and the lead package of the cable shall not expand or crack; Where the pressure and tension of the cable on the equipment shell are too large, the supporting point of the cable shall be intact; When checking the open trench of Indoor cables, the cables shall be prevented from being damaged; Ensure that the support is grounded and the heat dissipation in the trench is good.

04 grounding inspection

Metal cable trays and their supports and metal cable conduits leading in or out must be reliably grounded (PE) or connected to neutral (pen); The bridge shall be reliably connected with grounding wire.

PV module inspection

The energy of the photovoltaic system comes from the photovoltaic modules. The cracks, hot spots, dust accumulation, poor wiring and other phenomena of the photovoltaic modules will directly affect the power generation of the power station. Therefore, the inspection of the modules is very necessary. The inspection steps are as follows:

1. Component dust accumulation inspection

Component dust accumulation is the most common problem in operation. If the power station wants to generate high power, it is necessary to keep the daylighting surface of the components clean. If there is dust, it can be washed with soft brush and clean water. The use force should be small. It is forbidden to wipe the photovoltaic modules with hard objects. Do not clean them with corrosive solvents. In case of snow, it should be cleaned in time; The ash removal of components shall be carried out in the morning or evening when the light is weak.

2. Integrity inspection of photovoltaic modules

Photovoltaic modules shall be inspected regularly. For example, they shall be inspected once a quarter or every year. In case of broken glass, scorched back plate, battery discoloration, lax sealing of junction box, deformation, distortion, cracking or burning, loose connector, falling off, corrosion, etc., they shall be repaired or replaced in time.

3 photovoltaic module shielding inspection

The power station operates outdoors for a long time and is often unattended. It is necessary to check whether there are new plants or other objects around that have blocked the components. If there are shadows, they need to be handled in time to avoid affecting the components and power generation.

4. Component wiring inspection

For photovoltaic modules with metal frame, the frame and solar module installation support shall be in good contact to ensure that the installation bolts have been firmly connected to the oxide film of the aluminum frame, the frame must be firmly grounded, and the grounding resistance shall not be greater than 4 Ω.

5. String current inspection

The DC clamp type ammeter is used to measure the input current of each photovoltaic module string connected to the same inverter under the condition that the solar radiation intensity is basically the same. The current deviation of the same group of modules of the same model is generally no more than 5%. If the deviation is large, it needs to be checked in time.

06 Component thermal imaging inspection

If possible, it can be equipped with infrared thermal imager to regularly detect the temperature difference on the outer surface of photovoltaic modules; It can find the operation health status of all electrical equipment in the system in time, and prevent potential power loss and potential safety hazards in time.