Modeling and control of DC bus voltage for DC-module-based BIPV system

DC-module-based BIPV system, which has some advantages such as high energy conversion efficiency, good expandability and maintainability, consists of photovoltaic DC building module and centralized inverter paralleled with the DC bus, and is propitious to the building integrated application. However, the output power of every photovoltaic DC building module in the DC-module-based BIPV system is random and varying with illumination, temperature and etc. Furthermore, the parallel of many photovoltaic DC building modules ulteriorly increase the complexity of energy flow in the system. Consequently DC bus voltage controller is necessary to achieve energy balance and stability. Firstly the hypostasis of DC bus voltage control for the DC-module-based BIPV system is analyzed in this paper. Then the accurate dynamic model is built to analyze and design the controller. Finally the experimental results on a DC-module-based BIPV prototype verify the validity of the proposed DC bus voltage control strategy.