With the adjustment of the energy structure and the continuous leadership of the carbon neutral strategic goal of peak carbon, the investment in the construction of the distributed photovoltaic market has become more and more popular with many investors. The installation of photovoltaics is not only a contribution to environmental protection and energy structure transformation, but also a A stable investment, so the rate of return of photovoltaic power plants is closely related to the amount of electricity generated.
Some friends who install photovoltaic power stations sometimes encounter that the overall operating power of the power station is low when the power station is running, resulting in the power generation not reaching the reasonable value of the photovoltaic system of the same capacity in the area.
Reasons and Solutions for Abnormal Power Generation of Photovoltaic Power Stations
01
component problem
On-site photovoltaic modules are blocked, accumulate dust or are unqualified, resulting in low power generation of the power station. For example, there are utility poles, walls, etc. around the power station, the modules are not cleaned regularly, and the surface is seriously polluted.
Solution: It is recommended to deal with the obstructions around the photovoltaic power station in time. If it is an installation and design problem, it can be adjusted according to the site conditions, and the photovoltaic panels should be cleaned regularly with cotton items such as mops after soaking in water, and the defective photovoltaic modules should be replaced or removed in time.
02
Design and installation problems
①The number or models of photovoltaic modules connected to the same MPPT are inconsistent. Due to the "cask benefit", the MPPT of this line operates at the lowest photovoltaic string voltage, resulting in a decrease in power generation.
Solution: Check the voltage of the string connected to the inverter, and connect the PV modules of the same model, orientation, angle, and quantity to the same MPPT of the inverter.
② The maximum current of the photovoltaic module is higher than the maximum DC input current of the inverter, which causes the current-limiting operation of the DC input side of the inverter, and the operating power is lower than the reasonable power of the photovoltaic system.
Solution: For high-current components, a string inverter compatible with high-current input can be used, or when the current allows, reasonable configuration and installation can be used to reduce the number of strings connected to each MPPT.
③ The temperature of the working environment of the inverter is too high or there is no ventilation. For example, if it is placed in a direct sunlight position, in a small closed and unventilated space, or if there are baffles in its cooling air duct, the operation of the inverter will be limited by the ambient temperature. Temperature drop load.
Solution: The inverter should be installed in a well-ventilated area, and the cooling air duct of the inverter should be prevented from being blocked. It is recommended to place a sun visor above the inverter to avoid direct sunlight, which will help reduce the temperature of its working environment.
03
system operation problem
①System over-frequency derating: This function is for Class A inverters according to the requirements of 8.3.2.3 in the energy standard NB/T32004-2018. When the grid frequency exceeds 50.03Hz, the inverter will run with over-frequency derating.
Solution: If the inverter is in over-frequency and load-shedding operation, according to the on-site working conditions and local power supply requirements, you can consult an engineer to adjust this function on-site or remotely.
② Reasons for system reactive power compensation: The power factor of the on-site power supply system is lower than 0.9, and the inverter needs to generate reactive power to compensate the power supply system for reactive power. When the power factor of the inverter is adjusted, its active power output decreases, and the inverter In the state of "reactive power reduction";
Solution: In view of the "reactive power load reduction" state of the inverter, it is recommended to check whether the reactive power compensation function in the power supply system is normal. If it is not normal, it is necessary to increase or improve the reactive power compensation equipment of the power supply system.
③Limited power grid absorbing capacity: If the power grid absorbing capacity in the area is limited or the line loss is too large, the grid will be over-voltage, especially when the power generation power is high at noon. loss.
Solution: For the on-site system due to grid consumption or overvoltage problems, it is necessary to use a multimeter to detect the on-site grid voltage to find out the cause of the on-site voltage is too high, whether there is a wire diameter that does not match or cannot be absorbed locally. At the same time, the "overvoltage load reduction" function of the inverter can also be activated to prevent the system from being disconnected from the grid and causing more waste of power generation.
④ The inverter is turned on by mistake in constant voltage mode, resulting in low operating power of the inverter.
Solution: For the inverter to turn on the constant voltage by mistake, it can be cancelled through the following setting process
Setting process: advanced setting→special function setting→constant voltage mode setting→stop