Due to different use environments and technical requirements, the cables used in the low-voltage DC transmission part of the photovoltaic power generation system have different requirements for the connection of components. The overall factors that need to be considered are: cable insulation properties, heat and flame retardant properties, aging properties and wire diameter specifications. Specific requirements are as follows:

        1. The connection cable between the solar panel module and the module is usually directly connected to the connection cable connected to the module junction box. When the length is not enough, a special extension cable can also be used. According to the power of the module, the connecting cable has three specifications with cross-sectional areas of 2.5m㎡, 4.0m㎡ and 6.0m㎡. This is a connecting cable that uses double-layer insulation. The double-layer insulation is extremely resistant to ultraviolet rays, water, ozone, acid and salt, and has good abrasion resistance in all weather conditions.

        2. The connecting cable between the battery and the inverter should use a multi-strand flexible wire that has passed the UL test, and it must be connected as tightly as possible. Choosing short and thick cables can reduce system losses, increase efficiency and increase reliability.

        3. The connecting cable between the battery array and the controller or DC junction box should also use a multi-strand flexible wire that has passed the UL test. The cross-sectional area specification is determined by the maximum current output of the square array.

        The cross-sectional area of each section of the DC cable is determined according to the following principles:The connection cable between the solar cell module and the module, the connection cable between the storage battery and the storage battery, and the connection cable of the AC load. Generally, the rated current of the selected cable is 1.25 times the maximum continuous working current in each cable; solar arrays and squares are usually used to connect cables between arrays and between batteries (groups) and inverters. The rated current of the cable is 1.5 times the maximum continuous working current in each cable.

        The required characteristics of photovoltaic cables can be applied to photovoltaic power plants in different environments to ensure their long-term safe operation. The correct selection of cables with different components can maximize the stability of the system on a stable cost basis and ensure the long-term operating benefits of the substation.