Development Trend of Solar Inverters

The inverter is the brain and heart of the photovoltaic power generation system. During the solar photovoltaic power generation process, the power generated by the photovoltaic array is DC power. However, many loads require AC power. The DC power supply system has great limitations and is inconvenient to convert voltage. , the load application range is also limited. Except for special electrical loads, an inverter is required to convert DC power into AC power. The photovoltaic inverter is the heart of the solar photovoltaic power generation system. It converts the direct current generated by the photovoltaic modules into alternating current, delivers it to local loads or the power grid, and has power electronic equipment with related protection functions.

Solar inverters are mainly composed of power modules, control circuit boards, circuit breakers, filters, reactors, transformers, contactors and cabinets. The production process includes electronic parts pre-processing, complete machine assembly, testing and complete machine packaging. Its development depends on the development of power electronics technology, semiconductor device technology and modern control technology.

For solar inverters, improving the conversion efficiency of power supply is an eternal topic. However, when the efficiency of the system is getting higher and higher, almost approaching 100%, further efficiency improvement will be accompanied by low cost performance. Therefore, how to maintain A very high efficiency while maintaining good price competitiveness will be an important issue at present.

Compared with efforts to improve inverter efficiency, how to improve the efficiency of the entire inverter system is gradually becoming another important issue in solar energy systems. In a solar array, when a local shadow of 2%-3% of the area appears, for an inverter using an MPPT function, the system output power at this time will even decrease by about 20% when the power output is poor. In order to better adapt to situations like this, it is a very effective method to use one-to-one MPPT or multiple MPPT control functions for single or partial solar modules.

Since the inverter system is in grid-connected operation, the leakage of the system to the ground will cause serious safety problems; in addition, in order to improve the efficiency of the system, most solar arrays will be connected in series to produce a very high DC output voltage; for this reason, in Due to the occurrence of abnormal conditions between the electrodes, DC arcs can easily occur. Due to the high DC voltage, it is very difficult to extinguish arcs and can easily lead to fires. With the widespread adoption of solar inverter systems, system security issues will also be an important part of inverter technology.

In addition, the power system is ushering in the rapid development and popularization of smart grid technology. A large number of new energy power systems such as solar energy are connected to the grid, which poses new technical challenges to the stability of the smart grid system. Designing an inverter system that can be compatible with smart grids more quickly, accurately, and intelligently will become a necessary condition for solar inverter systems in the future.

In general, the development of inverter technology follows the development of power electronics technology, microelectronics technology and modern control theory. As time goes by, inverter technology is developing towards higher frequency, greater power, higher efficiency, and smaller size.