Nov 17, 2020
Detailed explanation of photovoltaic inverter
Photovoltaic inverters generally include power station photovoltaic inverters, string photovoltaic inverters and micro inverters. Power station type photovoltaic inverter, the power range from 30KW-1000KW, or even larger. Mainly used in large-scale commercial roofs, industrial plants and large-scale ground photovoltaic power stations. The power station type photovoltaic inverter is mainly based on the three-phase bridge circuit topology, and includes two types: transformerless and transformer.
string photovoltaic inverter, power range 1KW-30KW, mainly used in residential roofs and some small commercial roofs. The single-phase products of string-type photovoltaic inverters are mainly based on the boost circuit and single-phase transformerless topology, and the three-phase products are mainly based on the boost circuit and three-phase three-level transformerless topology.
The power of the micro inverter is 200W-500W, and it is mainly used on curtain walls, window sills and small roofs. The micro-inverter can be matched with a single component structure to track the maximum output power of each component separately to achieve efficiency optimization. In addition, it can also improve the shading problem and improve the efficiency and reliability of the solar photovoltaic system.
The main technical indicators of photovoltaic inverters
The conversion efficiency of photovoltaic inverters is high, and the conversion efficiency will directly affect the amount of electricity generated by the solar power system during the life cycle. According to different models, the conversion efficiency of world-class brand products can reach up to 98%. High-power photovoltaic inverters can reach a conversion efficiency of 98.7%, and the maximum power tracker efficiency can reach 99.9%.
The photovoltaic inverter has a long service life and high reliability. The design life of the photovoltaic power generation system is generally about 20 years, so the design life of the photovoltaic inverter needs to reach a higher level. At the same time, if the photovoltaic inverter fails, it will cause the photovoltaic power generation system to stop and bring economic losses. Therefore, high reliability is an important technical indicator of the photovoltaic inverter.
The DC voltage working range of the photovoltaic inverter should be wide and meet the requirements of grid connection. In practical applications, multiple solar cell modules are connected in series to obtain a higher DC voltage, which is input to the photovoltaic inverter after multiple sets of parallel connection. Components of different powers, voltages, and combinations of different series-parallel schemes require different DC voltage inputs that photovoltaic inverters can adapt. Therefore, the DC working voltage of the photovoltaic inverter should be wide to meet the different needs of customers. At the same time, the output current can not cause an impact on the power grid and meet the requirements of grid connection.