There are currently about 777 million sets of connectors installed in China. From a risk perspective, this means that there are at least 777 million risk points that need to be monitored by different plant owners.
However, this small component is often overlooked during the design, construction and operation stages of the plant. The reason has a lot to do with our understanding of MC4.
Maybe it's time to reintroduce MC4 together!
What is a PV connector?
There are many modules in the photovoltaic power station. What we are most familiar with and concerned about is the photovoltaic board. What brand is the photovoltaic board used, and what is the single crystal or polycrystalline, etc. Photovoltaic panels convert solar energy into direct current, and direct current is converted into alternating current through the inverter. There is a very important component at the entrance of the inverter, which can not be ignored. It is related to the "angle" of the entire photovoltaic project operation and maintenance! They are responsible for the successful connection of the power station!
The short name for the # MC interface is historical reason #
For PV connectors, 1996 and 2002 are two very important years. These two time points also coincide with key development nodes in the PV industry. Although the photovoltaic connector is not accompanied by the photovoltaic industry, its emergence on the rapid rise of photovoltaic installation has played a greater role in promoting.
Photovoltaic installed in the outdoor, year-round feng shui sun, then the most basic requirements of the connector is to adapt to this harsh environment, not only to waterproof, UV protection, but also to play the role of connection. When it comes to the link, because it is about electricity, the transmission process should also ensure watertight, safe and efficient transmission of power. So all this has to go through the life cycle of the PV system, which is at least 25 years.
1996 years ago, no special pv connector on the market, some solar cable connector USES the general screw terminal or joint fittings for connection, outside insulating tape, this method is time-consuming, laborious and unreliable. With the increase of amount of pv system installation, we hope to have a connection scheme is fast, safe and easy operation.
Therefore, in 1996, based on these application environment and market demand, a new type of plug-in connector came into being, which is the true sense of photovoltaic connector - MC3. It was invented by Swiss company Multi-Contact (merged into Staubil Group in 2002), MC stands for brand abbreviation, and 3 is the size of metal core diameter.
In 2002, the birth of MC4 redefined the PV connector once again, which truly realized "plug and play". The insulation is made of rigid plastic and is designed to be easier to assemble and install on site. After MC4 was launched, it was quickly recognized by the market and gradually became the standard for photovoltaic connectors. Many manufacturers refer to their connectors as "××MC4". If you search for MC4 on Alibaba, you can find about 44,000 related products, which shows the strong market influence of MC4.
MC4 With the change of market demand, Mc4-evo2 and Mc4-evo3 series have been launched successively. MC4 series connectors are fully capable of meeting the customer's demand for 1500V PV systems.
Technical risk of connector #
In the evaluation, design, procurement, construction, construction, operation and maintenance of photovoltaic power stations, there are uncertain risks (policy/technology/natural environment/law, etc.). If not properly controlled, it will affect the revenue of photovoltaic system.
For photovoltaic connectors alone, the technical risks are reflected in the aspects of quality, application, installation and operation and maintenance, as shown in the following figure.
The final summary
In the photovoltaic system, although the connector accounts for a small proportion, many links need to be used! Many construction personnel do not know enough about the connector, which may cause equipment failure. In the whole photovoltaic system, the DC side voltage is usually as high as 600-1000V. Once the photovoltaic module connector is loose and the contact is poor, it is easy to cause the DC arc pulling phenomenon. Dc arc pulling will lead to a sharp rise in the temperature of the contact part, and the continuous arc will produce a high temperature of 1000-3000℃, accompanied by high temperature carbonization of the surrounding devices. If it is light, it breaks the insurance and cable, and if it is heavy, it burns the equipment and causes a fire.
Therefore, although the connector is small, it is related to everyone's safety, therefore, it is very important to choose a good quality photovoltaic connector!