The photovoltaic grid-connected system consists of components, grid-connected inverters, photovoltaic meters, loads, two-way meters, grid-connected cabinets, and grids. Photovoltaic components generate direct current from sunlight and convert them into alternating current to supply loads and send them to the grid.

Grid-connected photovoltaic systems mainly have two modes of Internet access, one is "spontaneous self-use, surplus electricity goes online", and the other is "full online access".

Generally, distributed photovoltaic power generation systems mainly adopt the mode of "spontaneous generation and self-use, surplus electricity to go online". The electricity generated by solar cells is given priority to the load. When the load is not used up, the excess electricity is sent to the grid. The photovoltaic system can supply power to the load at the same time.
2. Off-grid power generation system

Off-grid photovoltaic power generation systems operate independently without relying on the power grid. They are generally used in remote mountainous areas, areas without electricity, islands, communication base stations, and street lights. The system is generally composed of photovoltaic modules, solar controllers, inverters, batteries, loads and so on. The off-grid power generation system converts solar energy into electrical energy when there is light, and powers the load through the integrated solar control inverter, while charging the battery; when there is no light, the battery powers the AC load through the inverter.

It is very practical for areas without power grids or areas with frequent power outages.
3. On-off grid energy storage system

Grid-connected photovoltaic power generation systems are widely used in places where there are frequent power outages, or where photovoltaics are spontaneously used and cannot be used to connect to the grid, the price of self-use electricity is much more expensive than the on-grid price, and the peak electricity price is much more expensive than the trough electricity price.

The system consists of photovoltaic modules, solar on-grid and off-grid all-in-one, batteries, loads, etc. The photovoltaic array converts solar energy into electric energy when there is light, and the load is supplied by the solar control inverter integrated machine while charging the battery; when there is no light, the battery powers the solar control inverter integrated machine, and then the AC Load power supply.

Compared with the grid-connected power generation system, this system adds a charge and discharge controller and a battery. When the grid is out of power, the photovoltaic system can continue to work, and the inverter can switch to off-grid working mode to supply power to the load.
4. Photovoltaic grid-connected energy storage system

The grid-connected energy storage photovoltaic power generation system can store excess power generation and increase the proportion of self-generation and self-use.

The system consists of photovoltaic modules, solar controllers, batteries, grid-connected inverters, current detection devices, loads, etc. When the solar power is less than the load power, the system is powered by the solar energy and the grid together. When the solar power is greater than the load power, part of the solar power supplies power to the load, and part of the unused electricity is stored by the controller.
5. Microgrid system

Micro-Grid is a new type of grid structure, a distribution network composed of distributed power sources, loads, energy storage systems and control devices. Distributed energy can be converted into electric energy on site, and then supplied to local loads nearby. Microgrid is an autonomous system that can realize self-control, protection and management. It can operate in parallel with the external grid or operate in isolation.

The microgrid effectively combines multiple types of distributed power sources to realize the complementation of multiple energy sources and improve energy utilization. It can fully promote the large-scale integration of distributed power sources and renewable energy sources, and realize the highly reliable supply of multiple forms of energy to the load. It is an effective way to realize the active distribution network, and it is the transition from the traditional power grid to the smart grid.

The micro-grid system is composed of photovoltaic modules, grid-connected inverters, PCS bidirectional converters, intelligent transfer switches, batteries, generators, loads, etc. Photovoltaic modules convert solar energy into electrical energy when there is light, and supply power to the load through the inverter, and at the same time charge the battery pack through the PCS bidirectional converter; when there is no light, the battery supplies power to the load through the PCS bidirectional converter .