Driven by the "double carbon" goals (carbon peaking and carbon neutrality), China's photovoltaic industry is experiencing unprecedented changes and leaps. In the first quarter of 2024, China's new photovoltaic power generation grid-connected capacity reached 45.74 million kilowatts, and the cumulative grid-connected capacity exceeded 659.5 million kilowatts, marking that the photovoltaic industry has entered a new stage of development. Today, we will explore in depth the composition and classification of grid-connected photovoltaic power generation systems. Whether it is the "self-use of distributed photovoltaic and grid-connected surplus power", or the large-scale grid connection of centralized photovoltaic. You can refer to it based on the text content.
Classification of grid-connected photovoltaic power generation systems
Grid-connected photovoltaic power generation systems can be divided into countercurrent grid-connected systems, non-countercurrent grid-connected systems, switching grid-connected systems, DC and AC grid-connected systems, and regional grid-connected systems according to whether the electric energy is sent to the power system.
1. Countercurrent grid-connected power generation system
When the power generated by the solar photovoltaic power generation system is sufficient, the remaining power can be sent to the public grid; when the power provided by the solar photovoltaic power generation system is insufficient, the power grid supplies power to the load. Since power is supplied to the grid in the opposite direction to the grid, it is called a countercurrent photovoltaic power generation system.
2. Grid-connected power generation system without countercurrent
Even if the solar photovoltaic power generation system generates sufficient power, it does not supply power to the public grid. However, when the solar photovoltaic power generation system provides insufficient power, it will be powered by the public grid.
3. Switching grid-connected power generation system
The switching grid-connected power generation system has the function of automatic two-way switching. First, when the photovoltaic power generation system generates insufficient power due to weather, whiteout failures, etc., the switch can automatically switch to the power supply side of the grid, and the power grid supplies power to the load; second, when the power grid suddenly loses power for some reason, the photovoltaic power generation system It can automatically switch to separate the power grid from the photovoltaic power generation system and become an independent photovoltaic power generation system. Generally, switching grid-connected photovoltaic power generation systems are equipped with energy storage devices.
4. Energy storage grid-connected power generation system
The grid-connected photovoltaic power generation system with energy storage device is to configure the energy storage device according to the needs in the above-mentioned types of grid-connected photovoltaic power generation systems. Photovoltaic systems with energy storage devices are highly proactive and can operate independently and supply power to the load normally when there is a power outage, power limit or failure in the power grid. Therefore, the grid-connected photovoltaic power generation system with energy storage device can be used as the power supply system for important places or emergency loads such as emergency communication power supply, medical equipment, gas stations, evacuation site indication and lighting.
5. Large-scale grid-connected power generation system
A large-scale grid-connected photovoltaic power generation system is composed of several grid-connected photovoltaic power generation units. Each photovoltaic power generation unit converts the DC power generated by the solar cell array into 380V AC power through the photovoltaic grid-connected inverter, and then turns it into 10KV AC high-voltage power through the booster system. It is then sent to the 35KV transformer system and merged into the 35KV AC power. In the high-voltage power grid, the 35KV AC high-voltage power is converted into 380~400V AC power through the step-down system as a backup power supply for the power station.
6. Distributed power generation system
Distributed photovoltaic power generation system, also known as distributed power generation or distributed energy supply, refers to the configuration of smaller photovoltaic power supply systems at the user site or close to the power consumption site to meet the needs of specific users and support the economy of the existing distribution network. operation, or both.
7. Intelligent microgrid system
Microgrid refers to a small power generation and distribution system composed of distributed power sources, energy storage devices, energy conversion devices, related loads, monitoring and protection devices. It is a system that can realize self-control, protection and protection. The managed autonomous system can operate in conjunction with the external power grid or in isolation. The microgrid is connected to the user side and has the characteristics of low cost, low voltage and low pollution. The microgrid can be connected to the large power grid, or it can be disconnected from the main grid and run independently when the power grid fails or is needed.
Composition of grid-connected photovoltaic power generation system
The photovoltaic array converts solar energy into DC power, combines it through a combiner box, and then converts the DC power into AC power through an inverter. The voltage level of the photovoltaic power station connected to the power grid is determined according to the capacity of the photovoltaic power station specified by the technology for connecting the photovoltaic power station to the power grid. , after the voltage is boosted by the transformer, it is connected to the public power grid.
Post time: Jul-15-2024