Our photovoltaic power plants, especially distributed photovoltaics, may encounter some common problems in actual operation, which not only the owner but also the installer must conduct a thorough investigation. We have summarized several common issues in photovoltaic power plants.
1. Possible reasons for not achieving ideal output power: There are many factors that affect the output power of photovoltaic power plants, including solar radiation, tilt angle of solar modules, dust and shadow blocking, and temperature characteristics of modules. Due to improper system configuration and installation, the system power is too low.
Solution:
(1) Before installation, check whether the power of each solar module is sufficient.
(2) Adjust the installation angle and orientation of the solar module.
(3) Check the solar modules for shadows and dust.
(4) Check if the voltage of the solar modules connected in series is within the voltage range. If the voltage is too low, the system efficiency will decrease.
(5) Before installing multi channel strings, check the open circuit voltage of each string, and the difference should not exceed 5V. If the voltage is found to be incorrect, check the circuit and connectors.
(6) During installation, it can be connected in batches. When each group is connected, the power of each group is recorded, and the power difference between the strings does not exceed 2%.
(7) The installation site is not well ventilated, and the heat from the inverter is not dissipated in a timely manner, or it is directly exposed to sunlight, causing the temperature of the inverter to be too high.
(8) The inverter has dual MPPT connections, with each input power only accounting for 50% of the total power. In principle, the design and installation power of each circuit should be equal. If only one MPPT terminal is connected, the output power will be reduced by half.
(9) Poor contact of cable joints, excessive length of cables, fine wire diameter, voltage loss, and ultimately power loss.
(10) The capacity of the grid connected AC switch in the photovoltaic power station is too small to meet the output requirements of the inverter.
2. Fault symptom: blown fuse
Possible cause: Short circuit of surge protector causing fuse to blow or module to be broken.
Solution: Replace the fuse and surge protector
3. Fault phenomenon: AC circuit breaker tripped
Possible cause: The connecting wire of a solar module in the middle of the photovoltaic string is connected to the photovoltaic bracket, which may be caused by damage to the insulation layer of the cable.
Solution: Check the connecting wires of the solar module, pay special attention to the areas where the connecting wires come into contact with the bracket, and identify the wires that are connected to the bracket.
4. Fault phenomenon: Abnormal open circuit voltage of solar module
Possible cause: The output voltage of the photovoltaic array is too low
Solution: Detect the solar module with abnormal open circuit voltage for each solar module in the string, detect its bypass diode, replace the diode if there is a problem, and replace the solar module if there is no problem with the diode.
5. Fault symptom: solar module installation error
Possible cause: During the installation of the solar module, due to being at an inclined angle, the solar module frame is subjected to stress and twisting forces, and due to the insufficient size of the flat gasket provided by the screws, the solar module frame detaches from the bracket under the action of wind.
Solution: Reinstall the bracket
