XINHUI takes you to understand the role of photovoltaic connector and its core technology

In a photovoltaic power station, to gather the power of a large number of components together and enter the inverter, it must rely on cables and connectors. The photovoltaic connector is one of the components, combiner boxes, controllers, and inverters in the photovoltaic power generation system. The key parts that are connected to each other.

As of the end of September 2018, my country's cumulative installed photovoltaic capacity was about 133GW, ranking first in the world. Calculated on the basis of 4000 sets of 1MW consumption, there are currently about 530 million sets of connectors in domestic photovoltaic power plants. Looking at it from a risk perspective, it means that there are at least 530 million risk points that need to be paid attention to by power station owners. Nevertheless, photovoltaic connectors are often overlooked during the design, construction, and operation and maintenance phases of power stations. The reason is that Everyone is not paying enough attention to the connector.

Previously, the editor also talked to you about the reasons for the failure of photovoltaic connectors in the operation and maintenance risks. This time the XINHUI editor will take you to understand the core technology and functions of photovoltaic connectors.

The photovoltaic system is exposed to wind, rain, scorching sun and extreme temperature changes for a long time, and the connector must be able to adapt to these harsh environments. They must not only be waterproof, high temperature resistant and weather resistant to ultraviolet rays, but also touch protection, high current-carrying capacity and high efficiency. At the same time, low contact resistance is also an important consideration. All of this must run through the entire photovoltaic system life cycle, at least 25 years.

(1) Shell insulation material

The application environment of photovoltaic connectors is generally very harsh, ranging from seaside salt-alkali land to plateau deserts and other terrains, from hot equator to cold high latitude areas, as well as perennial erosion such as solar radiation, rain and snow, and wind and sand, and the weather resistance of shell insulation materials Performance, heat resistance, flame retardancy, mechanical properties, insulation properties and other aspects are all very good, and it can be used for 25 years to ensure that the copper core inside and the outside are insulated.

(2) Seal

The inside of the photovoltaic connector is the copper core of the plug-in copper core and the copper core of the cable. It has no anti-corrosion function. The connector is required to keep the copper core isolated from the outside world. The on-board connector is still with the inverter (or controller), so To ensure the sealing function of the inverter, the sealing function of the connector must also be very reliable. In addition, the sealing screw must be tightened during installation.

(3) Contact resistance

According to the latest international standard IEC 62852 for photovoltaic connectors, after the test, the contact resistance of the male and female pairs should not increase more than 5 mΩ or the final resistance value should be less than 150% of the initial value. Using high-quality photovoltaic connectors, the power consumed on the connectors is less than one ten thousandth of the total power of the system, and the power consumed by inferior connectors is more than 30 times that of high-quality connectors. The root cause of the failure of the connector and the fire is: in the case of current flow, the contact resistance of the connector increases, which leads to an increase in temperature rise, which exceeds the temperature range that the plastic shell and metal parts can withstand. The contact resistance is mainly related to the material and size of the copper core. Connectors of different brands have different specifications. It is recommended not to mix them. During installation, the male and female connectors must be inserted in place, and the connectors of the regular brand will have a sound when they are inserted in place.

As a professional manufacturer of energy storage equipment connectors, XINHUI constantly pays attention to the development trends of the energy storage industry, constantly updates and creates new connector technologies. Ams products currently have functions such as anti-sparking, anti-reversal insertion, and large insertion force. In the choice of materials, PA66 nylon material with both mechanical and electrical properties is also selected. XINHUI can also develop and customize special high-current connector products according to customer needs.