There is a counter-current grid-connected photovoltaic power generation system: when the electric energy generated by the solar photovoltaic system is sufficient, the remaining electric energy can be fed into the public power grid to supply power (sell electricity) to the power grid; When the power provided by the solar photovoltaic system is insufficient, supply power to the load (buy electricity). Because the direction of power supply to the power grid is opposite to that of the power grid, it is called countercurrent photovoltaic power generation system.
2, no countercurrent grid-connected photovoltaic power generation system
Non-countercurrent grid-connected photovoltaic power generation system: solar photovoltaic power generation system does not supply power to the public grid even if the power generation is abundant, but when the power of the solar photovoltaic system is insufficient, the public grid supplies power to the load.
3. Switch grid-connected photovoltaic power generation system
The so-called switched grid-connected photovoltaic power generation system actually has the functions of automatic operation and bidirectional switching. First, when the photovoltaic power generation system is short of power due to cloudy days, rainy days, self-failure, etc., the switch can be automatically switched to the power supply side of the power grid, and the power grid supplies power to the load; Second, when the power grid does fail for some reason, the photovoltaic system can automatically switch, separating the power grid from the photovoltaic system and becoming an independent photovoltaic power generation system. Some switched photovoltaic power generation systems can also cut off the power supply to the general load and connect the power supply to the emergency load when necessary. General switching grid-connected power generation systems are equipped with energy storage devices.
4. Grid connected photovoltaic power generation system with energy storage device
Grid-connected photovoltaic power generation system with energy storage device: In the above photovoltaic power generation system, the energy storage device is configured as required. Photovoltaic system with energy storage device has strong initiative. When the power grid is blacked out, limited or broken, it can operate independently and supply power to the load normally. Therefore, the grid-connected photovoltaic power generation system with energy storage device can be used as the power supply system for emergency communication power supply, medical equipment, gas station, shelter indication, lighting and other important or emergency loads.