An inverter, also referred to as an inverter power supply, is a device that converts direct current (DC) power into alternating current (AC) power. A photovoltaic inverter specifically pertains to the utilization of inverters within solar photovoltaic power generation systems. It functions as an electronic apparatus that transforms DC power generated by solar cell modules into adjustable frequency AC power, which can be either fed back into commercial transmission systems or utilized for off-grid power grids.
The photovoltaic inverter is composed of a boost loop and an inverter bridge loop. The boost loop raises the DC voltage to the DC voltage required by the inverter output, and the inverter bridge loop converts the boosted DC voltage into the AC voltage of the common frequency. It not only has the function of DC-AC conversion, but also has the function of maximizing the performance of solar cells and the function of system fault protection. The photovoltaic inverter is one of the important components of the photovoltaic power generation system equipment, which can directly affect the power generation efficiency of the solar photovoltaic system.
According to different power, photovoltaic inverters can be divided into centralized inverters, series inverters, distributed inverters and micro-inverters, the main difference is that the inverter single capacity and the number of photovoltaic modules directly connected with it is different, but also has different downstream application scenarios.
Centralized inverter is a series of parallel photovoltaic group connected to the DC input of the same centralized inverter, the maximum power peak tracking, through the inverter into the power grid. The single capacity of the centralized photovoltaic inverter is usually more than 500kW, which is mainly suitable for the centralized ground large-scale plants and power stations with uniform light; The series photovoltaic inverter is to track the maximum power peak of 1-4 groups of photovoltaic series separately, and then merge into the AC power grid after inverter. The single capacity of series photovoltaic inverters is usually below 100kW, which is mainly suitable for distributed power generation systems; The power of distributed inverters is usually between centralized inverters and serial inverters.
The micro photovoltaic inverter is to track the maximum power peak of each photovoltaic module separately, and then integrate into the AC power grid after inverter. The single capacity of micro-photovoltaic inverters is generally below 1kW, which is mainly suitable for distributed household use and small and medium-sized industrial and commercial rooftop power stations.
Energy storage is a key support for large-scale development of renewable energy. Energy storage is of great significance to the use of new energy, is an important part of the energy revolution, for example, photovoltaic power generation, as a kind of intermittent energy, power generation fluctuations will have an impact on the power grid system, light storage integration can inhibit the impact to a certain extent, is conducive to the realization of photovoltaic power flexible grid connection and full absorption.
The energy storage inverter is a necessary link in the energy storage system industry chain: the energy storage inverter is a device connected to the battery system and the power grid to realize the bidirectional conversion of electric energy, which can convert the direct current of the battery into alternating current and send it to the power grid or to the AC load. The alternating current of the power grid can also be rectified into direct current to charge the battery.
The energy storage inverter integrates the functions of photovoltaic grid-connected power generation and energy storage power station, which can overcome the shortcomings of photovoltaic modules' unstable power generation due to weather changes and improve the quality of the grid. It can also store electric energy through the trough, and output electric energy through the peak, greatly reduce the peak power generation of the grid, greatly increase the capacity of the grid, and improve the utilization rate of the grid.
Energy storage converters and photovoltaic inverters are basically the same in principle and have the same technical origin. For the original photovoltaic inverter manufacturers, the energy storage business is a pure incremental business, so many photovoltaic inverter manufacturers began to develop energy storage converter business.
