The introduction and function of the photovoltaic junction box
The photovoltaic junction box is a connecting device between the solar panel array formed by solar cells and the solar charge controller. Its primary function is to connect and protect the photovoltaic modules, linking the electricity generated by the solar cells to external circuits and conducting the current produced by the photovoltaic modules.
The junction box has two main functions: connection and protection. The connection function is to guide the current generated by the photovoltaic modules through cables and connectors into the electrical devices. To reduce the loss within the junction box, the conductive material's resistance and the contact resistance should be as low as possible. The protection function consists of two parts: one is to protect the photovoltaic module and enhance its power output under fault conditions, such as shading, using bypass diodes; the other is to use special materials for sealing and heat dissipation design to achieve waterproofing, fireproofing, and reducing the operating temperature of the junction box, thereby protecting the photovoltaic module and minimizing power loss caused by leakage currents from the bypass diodes.
With the continuous increase in the power of solar modules and the year-on-year improvement in cell conversion efficiency, the operating current in photovoltaic systems has significantly increased. As an important device for both connection and protection between solar modules, the junction box plays a crucial role in the power output and circuit protection of the photovoltaic modules, requiring higher current-carrying capacity.
The current-carrying capacity is closely related to factors such as heat dissipation, conductivity efficiency, and reliability. Therefore, manufacturers of photovoltaic junction boxes must keep pace with technological innovations to adapt to the rapid development of solar cell technology. The development trend for photovoltaic junction boxes is moving towards higher current-carrying capacity, better heat dissipation, higher system stability, and lower production costs.
This is an introduction to the functions of photovoltaic junction boxes provided by Hengyuan Tai.