company news about The necessity of installing fuse in photovoltaic power stations

For the photovoltaic (PV) system, choosing an appropriate fuse is essential for the long -term, safe and reliable operation of photovoltaic power stations. Different from the typical power distribution and control applications, in the photovoltaic system, the fuse is unique. Elements exposed in the environment for a long time will produce abnormal ambient temperatures, which will affect the performance of fuse, the selection and size of the conductor. In addition, unlike traditional circuits based on continuous loads, components can generate continuous current, which causes additional considerations when adjusting the fuse.

The fuse is required to protect the cable and photovoltaic components from the line, line land, and non -matching failure. The only purpose is to prevent fires from fire and open the fault circuit safely when the current occurs. However, in some cases, the use of fuse is not necessary, but from the following:

Single -string component

In the photovoltaic component or photovoltaic system, there is no external power connection (for example, the source circuit, battery or inverter's reverse feeder) and the connection line is rated to 1.56 or higher, and no fuse is required. Essence

Two string components parallel (no fuse required)

If the short -circuit current of all conductors exceeds the ampel volume of the conductor or the maximum fuse rated current specified on the PV component nameplate, no fuse is required. In this scene, each component can generate an ISC with a maximum circuit current of 1.25 times. As long as the connection line rated at 1.56 times or higher, the connected circuit fault current will not be large enough to cause damage to the cable or component, so there is no need to use a fuse. At most 2 string components parallel, even if there is a short circuit failure, the maximum anti -irrigation current will not exceed 10A, so it is safe, no fuse is required for protection

Three strings or more parallel (need fuse)

In this case, any failure in a group string will affect the impact of the maximum short -circuit current reflux of all other connected groups; in the worst case, each group needs to pass 1.25 times ISC. Current. The connected fault current will be greater than the rated current selected according to 1.56 times ISC. Under this failure, components, etc. will be damaged; therefore, fuses are necessary

Taking a typical centralized power station as an example, the number of groups connected by parallel is as high as 100 string. When there is a short -circuit failure, the current of all groups will be used to reflect the failure group. Safety requirements for cables and components.