Classification of photovoltaic power generation systems
Photovoltaic power generation systems are divided into independent photovoltaic power generation systems, grid-connected photovoltaic power generation systems and distributed photovoltaic power generation systems.
1. Independent photovoltaic power generation is also called off-grid photovoltaic power generation. It is mainly composed of solar cell components, controllers, and batteries. If you want to supply power to the AC load, you also need to configure an AC inverter. Independent photovoltaic power plants include power supply systems for villages in remote areas, solar household power systems, communication signal power supplies, cathodic protection, solar street lights, and other photovoltaic power generation systems with batteries that can operate independently.
2. Grid-connected photovoltaic power generation means that the direct current generated by solar modules is converted into alternating current that meets the requirements of the mains power grid by a grid-connected inverter and then directly connected to the public grid.
It can be divided into grid-connected power generation systems with and without batteries. The grid-connected power generation system with storage battery is schedulable and can be merged into or out of the grid as needed. It also has the function of backup power supply, which can provide emergency power when the grid is out of power. Photovoltaic grid-connected power generation systems with batteries are often installed in residential buildings; grid-connected power generation systems without batteries do not have the function of dispatchability and backup power, and are generally installed on larger systems. Grid-connected photovoltaic power generation has centralized large-scale grid-connected photovoltaic power stations, which are generally national-level power stations. The main feature is that the generated energy is directly transmitted to the grid, and the grid is uniformly deployed to supply power to users. However, this kind of power station has a large investment, a long construction period, and a large area, and it has not developed much yet. Distributed small grid-connected photovoltaics, especially photovoltaic building-integrated photovoltaic power generation, are the mainstream of grid-connected photovoltaic power generation due to the advantages of small investment, fast construction, small footprint, and large policy support.
3. Distributed photovoltaic power generation system, also known as distributed power generation or distributed power supply, refers to the configuration of a smaller photovoltaic power supply system at the user site or close to the power site to meet the needs of specific users and support the existing power distribution network Economic operation, or meet the requirements of these two aspects at the same time.
The basic equipment of a distributed photovoltaic power generation system includes photovoltaic cell components, photovoltaic square array brackets, DC combiner boxes, DC power distribution cabinets, grid-connected inverters, AC power distribution cabinets and other equipment, as well as power supply system monitoring devices and environmental monitoring Device. Its operation mode is that under the condition of solar radiation, the solar cell module array of the photovoltaic power generation system converts the output electric energy from the solar energy, and sends it to the DC distribution cabinet through the DC combiner box, and is inverted by the grid-connected inverter into AC power supply. The building's own load, surplus or insufficient power is adjusted by connecting to the grid.
