The photovoltaic grid-connected cabinet is a power distribution device that connects the photovoltaic power station and the power grid, and its main function is to separate the photovoltaic power station from the power grid. For low-voltage grid-connected photovoltaic power stations, photovoltaic grid-connected cabinets can also refer to measurement and some protection functions. As the total outlet of the photovoltaic power station, the photovoltaic grid-connected cabinet must exist in the photovoltaic system.

What electrical appliances are in the photovoltaic grid-connected cabinet?

As can be seen from the figure below, the composition of the photovoltaic grid-connected cabinet is composed of anti-island protection device, low-voltage circuit breaker, air switch, lightning arrester, temperature and humidity heater, stainless steel box and other equipment. The choice of circuit breaker depends on the actual current flowing through the circuit breaker, which is generally about 1.2 times the rated current.

The above is routine. Depending on the project, the equipment in the distributed grid-tied cabinet is also different. Some projects require the installation of watt-hour meters or other equipment in grid-tied cabinets, depending on the project. Friends often ask where to install the photovoltaic island protection device is actually very simple. The main functions of the island protection device are high-frequency protection, low-frequency protection, high-voltage protection, low-voltage protection, reverse power protection, etc. When a fault is detected, the island protector skips the grid-tied circuit breaker.

Therefore, it is most appropriate to install an anti-islanding protection device in the grid-connected cabinet. It should be noted that the anti-islanding protection device is one of the microcomputer protection, and it also needs to be debugged and experimented during use. At least the setting of the protection value needs to be set by the on-site electrical commissioning personnel according to the protection value given by the relevant department. If no fixed value is set, the protective device will be invalid.

The photovoltaic combiner grid-connected cabinet is suitable for the AC 50Hz, rated working voltage of 380V, and rated working current of 2000A for power users such as ground centralized, ground string, and ground distributed, and is used for power conversion, distribution and control of power, lighting and distribution equipment.

The product has the characteristics of high breaking capacity, good dynamic and thermal stability, flexible electrical scheme, convenient combination, strong practicability, novel structure and high protection level. It can be used as a replacement product for low-voltage switchgear.

Conditions of normal use

◆The ambient air temperature is not higher than +40°C and not lower than -5°C. The average temperature within 24h must not be higher than +35°C.

◆ For indoor installation and use, the altitude of the place of use shall not exceed 2000m.

◆The relative humidity of the surrounding air does not exceed 50% at a maximum temperature of +40°C, and a greater relative humidity is allowed at lower temperatures. (e.g. 90% at +20°C) The effects of occasional condensation due to temperature changes should be taken into account.

◆ The inclination of the equipment to the vertical plane when installed shall not exceed 5%.

◆ The equipment should be installed in a place where there is no violent vibration and impact, and where it is not enough to corrode the electrical components.

◆ When the user has special requirements, negotiate with the manufacturer to solve the problem.