Driven by the “double carbon” goal, large-scale development and utilization of new energy has become an inevitable choice for China’s power system. As an efficient and non-polluting new energy source, solar energy has become an important part of today’s energy structure. Photovoltaic grid-connected power generation technology has become the mainstream of solar photovoltaic applications.
Photovoltaic grid-connected equipment exists in the photovoltaic system as the total outlet of the photovoltaic power station. It is a power distribution device connecting the photovoltaic power station and the grid. It can protect and measure the total amount of photovoltaic power generation, facilitate fault maintenance management, and improve the safety and economy of the power generation system. benefit. Possess all-round multiple protection functions such as voltage loss detection and opening, voltage detection and closing, overcurrent protection, overvoltage protection, island protection, anti-backflow protection, harmonic control, reactive power compensation, etc. Parameters and status indicators are widely used in photovoltaic power generation systems, and can be used together with photovoltaic grid-connected inverters to form a complete photovoltaic power generation system solution.
A series of photovoltaic grid-connected equipment such as photovoltaic grid-connected boxes and photovoltaic grid-connected cabinets developed by Shanghai Huijue Network Communication Equipment Co., Ltd. are mainly used in distributed photovoltaic power generation projects of AC 400V low-voltage systems. The low-voltage photovoltaic grid-connected cabinet mainly includes anti-islanding protection devices (failure disassembly devices, power quality online monitoring devices can also be installed), isolating knife switches, grid-connected circuit breakers, lightning protection devices, temperature and humidity controllers, power metering devices and cabinet etc. The main functions of the photovoltaic grid-connected cabinet are:
The anti-islanding device has passive island detection, automatic closing under pressure, over and under voltage protection, high and low frequency protection, reverse power protection, etc.
·Automatic grid connection
The anti-islanding protection device has the functions of voltage loss tripping (power grid loss of voltage) and voltage automatic reclosing. It trips when the voltage is abnormal, and can automatically close the grid when the voltage returns to normal. At the same time, it has an intelligent communication function, which can communicate with the background system to form a network, remotely operate the circuit breaker to open and close, and remotely view various electrical parameters and switch position information of the grid-connected cabinet.
The voltage photovoltaic grid-connected cabinet can be equipped with a metering bin, and the metering bin is equipped with a lead seal device, which can effectively prevent electricity theft. Metering devices and load control devices (generally provided by local power supply bureaus) can be installed in the metering warehouse, which can record the power generation well.