Shanghai Changgao Jibaoofcgs7003tThe anti-backflow protection device, also known as the reverse power protection device, is a kind of equipment used to protect the distributed photovoltaic power generation system, and is the main equipment constituting the photovoltaic anti-backflow grid-connected box. The main function is to prevent distributed power generation from reversing power to the power grid, so as to ensure the safe and stable operation of the power grid. Anti-backflow protection devices usually consist of current sensors, controllers, and circuit breakers, among others. By monitoring the output power of the distributed power generation and the input power of the power grid, it is possible to determine whether there is a reverse power situation. When the output power of the distributed generator is greater than the input power of the power grid, the reverse power protection device will act immediately to cut off the connection between the distributed generator and the power grid to prevent the distributed generator from reversing the power to the grid. It is usually used in distributed power systems, such as solar power generation, wind power generation, etc. It can effectively protect the safe and stable operation of the power grid and avoid the adverse impact of distributed power generation on the power grid.
The photovoltaic anti-backflow grid-connected box is mainly used for the equipment of the distributed photovoltaic power generation system, and its main function is to prevent the electrical energy generated by the photovoltaic system from flowing backward into the power grid, so as to ensure the safety and stability of the power grid. The installation location of the anti-reverse current grid-connected box is usually at the outlet of the photovoltaic system, which is mainly composed of reverse power protection device, input switch, power meter, grid-connected contactor, surge protector, photovoltaic isolation switch and other equipment. By monitoring the direction of the current to determine whether there is a counter-current situation, when the counter-current phenomenon occurs, it can cut off the connection between the photovoltaic side and the grid side, so as to realize the function of self-generation and self-consumption of the photovoltaic system, and the surplus electricity is not connected to the Internet.
In the photovoltaic grid-connected system of "self-generation and self-consumption, and the surplus electricity is not connected to the grid", the excess power generated by the photovoltaic system is not allowed to flow back to the grid side. Counterflow refers to the fact that when the power generated by solar panels exceeds the demand of the grid, the electrical energy will flow backwards into the grid, causing adverse effects on the grid. The hazards of countercurrent mainly include the following aspects:
Affect the stability of the power grid
Countercurrents can cause changes in the voltage and frequency of the grid, which can affect the stability of the grid. If the backflow is too large, it can cause the power grid to collapse, causing widespread power outages.
Affect the quality of the power grid
It can cause voltage and current fluctuations in the power grid, which can affect the quality of the power grid. Countercurrents can also generate harmonics and reactive power, causing damage to equipment in the grid.
Affect grid dispatching
It will lead to a change in the load of the power grid, which will affect the dispatch of the power grid. If the backflow is too large, it may lead to difficulties in grid dispatching and affect the normal operation of the power grid.
Photovoltaic systems produce the hazard of countercurrents.
Prevent backflow
When the power generated by the distributed generation system exceeds the demand of the power grid, the anti-backflow grid-connected box can automatically cut off the connection between the distributed generation system and the power grid, preventing the power from flowing backwards into the power grid, so as to ensure the safety and stability of the power grid.
Monitor the current
The photovoltaic anti-backflow grid-connected box can monitor the current direction and size of the distributed power generation system in real time, so as to detect the backflow situation in time and take corresponding measures.
Automatic control
The opening and closing of the circuit breaker can be automatically controlled according to the signal of the current sensor, so as to realize the automatic control of the distributed generation system.
Protect the device
The anti-backflow grid-connected box can protect the equipment in the distributed generation system and the power grid to avoid damage to the equipment caused by backflow.