Thermal modeling of the module integrated DC-DC converter for flexible thin-film PV modules

Recently there is a trend in PV systems toward a more granular processing of the PV array power by means of distributed maximum power point tracking (DMPPT). This is achieved by connecting a DC-DC converter to each PV module in a PV system and thus performing power processing on a module level as opposed to centralized power processing in traditional PV system architectures. In order to decrease the manufacturing costs and to improve the level of integration, the converter can be directly integrated into the PV module. This on the other hand brings tight thermal coupling between the PV module and the integrated converter and introduces additional heat to the PV module which may deteriorate its performance. It is therefore important to model the thermal behavior of the system in order to estimate reached temperatures and to test the effectiveness of different converter thermal management strategies. This paper presents an investigation into the thermal behavior of a DC-DC converter integrated into a flexible PV module. The goal of this work is to develop analytical thermal models of the PV module and the integrated converter that will allow to quickly predict the reached system temperatures for a set of PV module and converter specifications and boundary conditions. Finally, the results obtained from the developed thermal models show satisfying accuracy when compared to the experimental results and the results obtained using computational fluid dynamics (CFD) simulations.