Façade building-integrated photovoltaics is a technology that transforms a passive façade into a distributed, renewable electrical generator by the inclusion of solar cells in the building envelope. Partial shading due to nearby objects is a typical problem for façade building-integrated photovoltaics as it strongly reduces the output power of the installation. Distributed maximum power point tracking by means of embedded converters and a common direct current bus has been proposed to alleviate this issue. However, the bus voltage plays an important role in converter topology selection and overall efficiency, although this is not being covered in literature. Also the influence of the solar cell technology on the output voltage of the module is not studied before, although it strongly influences the converter topology selection and the losses. In this paper, a methodology is described to investigate the influence of the voltage level and solar cell technology by taking conversion losses in the converters and the cabling into account. The methodology is applied to two case study buildings for which four different cell technologies are considered. It is shown that overall high efficiencies are obtained, regardless of the voltage level. However, the loss distribution changes significantly with the voltage. This aspect can be used advantageously to reduce thermal stresses on the embedded converter. Furthermore, the overall system efficiency is typically higher when the voltage step-up is lower.@en

Reliability of DC-DC converters is important in photovoltaic (PV) applications like building integrated PV systems, where the module-level converter may be stressed significantly. Understanding and predicting the most life-limiting components with accurate degradation models in such systems enable the design for reliability. In this paper, a mission profile-based reliability analysis framework for PV DC-DC converters is proposed where the inputs and models of the framework can be adjusted according to the converter topology, the components and the failure mechanisms under investigation. The framework is demonstrated by comparing the influence of two yearly mission profiles on the solder joint degradation of a MOSFET in an interleaved boost converter. This is done by using an electro-thermal circuit simulation in PLECS and a finite element MOSFET model in COMSOL. This framework allows for exploring more accurate models or even simplifying parts with low sensitivity in order to obtain a thorough understanding of their accuracy and to determine the overall converter reliability.@en