Reduction of Heat Generation from Junction Box in 3 kW Photovoltaic Power Generation System

Abstract

A junction box used in a 3 kW photovoltaic power generation system plays a role in collecting and supplying the direct current voltage produced by photovoltaic modules to an inverter. It is also used for facilitating maintenance checks and protecting the module and inverter by keeping the voltage constant. As for the junction box, using it in a parallel connection creates a difference between the setup modules. In order to compensate, an inverse voltage diode is used. But the high-power created through the solar generator can be delivered to the inverter through the inverter regularly. Therefore, a component can break down due to excess heat. And consequently short circuits and electric leakage occurs. In this study, using a junction box that enabled the bypass of high electric power, it was possible to reduce heat generation by approximately 35℃ when compared to a standard junction box.

The Improvement of Junction Box Within Photovoltaic Power System

“…Such a junction box is sometimes used to confirm the generation between the modules, but it is mostly used to prevent damage to the modules due to the inverse current created during the grid connection as well as to secure the safety of the serially connected modules [9]. For such purposes, the use of a reverse blocking diode is essential and such use may create some unnecessary heat during the generation.…”

“…In addition, the generation environment rapidly increases the internal temperature. Such increase in temperature can cause problems such as insulation and softening of elements due to energy loss and heat accumulation during the kW or more levels generation; such problems can lead to fire accidents [9]. In this research, in order to minimize the heat generation within the junction box, a bypass junction box capable of directly transferring the electric power generated from the PCS without using the diode used for preventing the inverse voltage was designed and manufactured.…”