The function of inverter in photovoltaic power station

As the core of photovoltaic power station, inverter plays a main role in converting the irregular direct current of photovoltaic module into sine wave alternating current, and has the functions of over voltage, over current protection, insulation resistance protection, leakage current protection, grid voltage and frequency abnormal protection, etc.

The application of potential Induced degradation, arc fault circuit Interrupters,rapid shutdown technologies can further improve the safety and reliability of the photovoltaic system, postpone the attenuation of the components and improve the economic efficiency.

Fire is the greatest economic loss of photovoltaic power plants, if installed in the factory or residential roof, it is also easy to jeopardize the safety of people. If a fire occurs in a photovoltaic power station, it cannot be directly extinguish with water. First, we need to cut off the power at the fastest speed. There are many factors of fire accidents in photovoltaic power plants. The main reason is DC arcing.

In the photovoltaic system, the DC side voltage is usually as high as 600-1000V. Because of the loose connection of PV module joints, the poor contact, the wire wetting and the insulation rupture, it is easy to cause DC arcing.

DC arcing will lead to a sharp rise in the temperature of the contact part. The continuous arc will generate a high temperature of 3000-7000 degrees. With the high temperature carbonization around the device, light will fuse the fuse and cable, and the heavy burned components and equipment will cause a fire. At present, the UL and NEC security rules have the mandatory requirements for the pull arc detection function for the DC system above 80V. Since PV system cannot be extinguished directly after fire, early warning and prevention are very important. Especially for color steel tile roofs, maintenance personnel are hard to detect fault points and hidden dangers, so installing inverter with arc detection function is very necessary.

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