The energy storage inverter integrates the functions of photovoltaic grid-connected power generation + energy storage power station. It stores electric energy when the electric energy is surplus, and when the electric energy is insufficient, the stored electric energy is inverted and output to the grid, which plays the role of peak shaving and valley filling. One of the main development directions in the future.

The photovoltaic inverter is the control center of the photovoltaic power generation system, which can convert the direct current generated by the components into alternating current to achieve grid connection or load use. Photovoltaic inverters are mainly composed of power conversion modules, microcomputer control modules, EMI modules, protection circuits, monitoring modules, and human-computer interaction modules. Its development depends on the development of electronic circuit technology, semiconductor device technology and modern control technology.

Technology trend 1: Power modularization accelerates string penetration, and new and replacement needs resonate.

According to the working principle, photovoltaic inverters can be divided into centralized, string and micro inverters. Due to the different working principles of various inverters, the application scenarios are also different:

(1) The centralized inverter first converges and then inverts, which is mainly suitable for large-scale centralized power station scenes with uniform illumination. The centralized inverter first converges multiple parallel strings to the DC input terminal, after tracking the maximum power peak, and then centrally converts it to AC power. Usually, the unit capacity is more than 500kw. It is mainly used in large-scale plants with uniform sunshine, large-scale centralized photovoltaic power stations such as desert power stations.

(2) String inverters first invert and then converge, and are mainly suitable for scenarios such as small and medium-sized roofs and small ground power stations. The string inverter is based on the modular concept. After 1-4 sets of photovoltaic strings are individually tracked for maximum power peaks, the direct current generated by them is first converted to alternating current, and then converged and boosted and connected to the grid, so the power It is smaller than the centralized type, but has richer application scenarios. It can be applied to various types of power stations such as centralized power stations, distributed power stations, and rooftop power stations. The price is slightly higher than that of centralized power stations.

(3) The micro-inverter directly inverts and connects to the grid, which is mainly suitable for household use and small distributed scenarios. The micro-inverter performs individual maximum power peak tracking for each photovoltaic module, and then merges into the AC grid through the inverter. Compared with the first two inverters, it has the smallest volume and the smallest power, and the general power is below 1kw. It is mainly suitable for distributed households and small distributed industrial and commercial rooftop power stations, but the price is high and it is difficult to maintain once a failure occurs.