Solar photovoltaic power generation systems are generally divided into five types according to different application scenarios: grid connected power generation systems, off grid power generation systems, hybrid energy storage systems, grid connected energy storage systems, and multi energy hybrid microgrid systems.
1. Grid connected photovoltaic power generation system
The photovoltaic grid connected system consists of photovoltaic modules, photovoltaic grid connected inverters, photovoltaic meters, loads, bidirectional meters, grid connected cabinets, and the power grid. The photovoltaic modules generate direct current from sunlight, which is converted into alternating current by the inverter to supply the load and the power grid. There are two main modes of grid connected photovoltaic systems, one is "self use and surplus electricity grid connection", and the other is "full grid connection".
The general distributed photovoltaic power generation system mainly adopts the "self use and surplus electricity grid connection" mode. The electricity generated by solar cells is given priority to the load. When the load cannot be used up, the excess electricity is sent to the grid. When the power supply to the load is insufficient, the grid and photovoltaic system can simultaneously supply power to the load.
2. Off grid photovoltaic power generation system
Off grid photovoltaic power generation systems operate independently without relying on the power grid and are generally used in remote mountainous areas, areas without electricity, islands, communication base stations, and street lamps. The system generally consists of photovoltaic modules, solar controllers, inverters, batteries, loads, etc. The off grid power generation system converts solar energy into electrical energy under illumination, and supplies power to the load and charges the battery through a solar controlled inverter integrated machine; When there is no light, the battery supplies power to the AC load through an inverter.
It is highly practical for areas without power grids or areas with frequent power outages.
3. Off grid photovoltaic energy storage system
Off grid photovoltaic power generation systems are widely used in places where there are frequent power outages, or where photovoltaic self use cannot generate surplus electricity for grid connection, the self use electricity price is much higher than the grid connection electricity price, and the peak electricity price is much higher than the valley electricity price.
The system consists of photovoltaic modules, solar off grid integrated machines, batteries, loads, etc. The photovoltaic array converts solar energy into electrical energy under illumination, and supplies power to the load and charges the battery through a solar controlled inverter integrated machine; When there is no light, the battery supplies power to the solar controlled inverter integrated machine, and then supplies power to the AC load.
Compared to grid connected power generation systems, this system adds a charge and discharge controller and a battery. In the event of a power outage, the photovoltaic system can continue to operate, and the inverter can switch to off grid mode to supply power to the load.