When the grid-connected inverter shows an AC overvoltage problem, how to check and solve it?

　　Nowadays, home-style PV power generation systems are becoming more and more popular. However, ordinary people are still not as familiar with PV power generation systems as they are with TVs and refrigerators.

　　Therefore, when the PV power generation system, especially the PV inverter, has fault information, everyone seems helpless. Therefore, we need to understand how to solve the inverter failure tips to ensure that the inverter works normally.

　　In principle, the PV inverter itself does not generate voltage. Part of the voltage displayed by the inverter comes from PV modules, called DC voltage, and the other part comes from the grid, called AC voltage.

　　According to relevant standards, PV grid-connected inverters must work within the specified grid voltage range. When the inverter detects that the grid voltage (AC voltage) exceeds the specified range, the inverter must stop working to ensure equipment safety and personnel safety.

　　When the grid-connected inverter shows an AC overvoltage problem, it is nothing more than the following three situations:

　　Situation 1: The grid-connected distance is too far, causing the voltage to rise

　　If the grid-connected inverter is too far from the grid-connected point, the cables used are too long, too thin, twisted, or the material is not in compliance, etc., the voltage difference on the AC terminal side of the inverter will increase, which exceeds the inverter. In the voltage range specified by the inverter, the inverter will display the grid overvoltage.

　　In view of this situation, first check whether the grid connection distance is too long, and it is best to choose the nearest grid connection plan; second, check the cable distribution and cable quality, and choose a reasonable wiring method and qualified AC cables.

　　Situation 2: One access point for multiple inverters

　　Many installation companies have insufficient experience and sometimes appear unprofessional or lack thorough consideration. It is often the case that multiple single-phase inverters are connected to the same phase, which can easily lead to unbalanced grid voltages and cause the system to display excessively high grid-connected voltages.

　　This situation is relatively easy to solve. The grid-connected power generation of the project can be equally distributed to the three phases of the grid, and multiple points can be selected for grid-connection.

　　Situation 3: The installed PV capacity of the same area is too large

　　It is possible that there are too many PV installed capacity in the same area, and the grid load digestion capacity is insufficient. Since the electricity generated by the PV power generation system cannot be consumed nearby and cannot be transmitted over long distances, the grid voltage will continue to rise.

　　The solution to this situation is: 1. Derating the PV power station. 2. Increase the capacity of the transformer. 3. Do a good job in the preliminary survey of the grid to evaluate the appropriate grid-connected capacity (the best method).

　　Lithium-ion battery (LIB) has become the main energy storage solution in modern social life. Among them, lithium iron phosphate batteries are a perfect replacement for lead-acid batteries, and they are the first choice for grid-connected peak shaving, off-grid energy storage, PV energy storage, UPS, data center and other industries.

　　Solar power generation system with lithium battery energy storage system is a very promising clean energy.