Multifunctional Integrated Distributed Power Generation System

With the aggravation of global energy crisis and environmental pollution, energy saving, environment protection and developing of green energy have become a trend. New types of distributed energy generation systems have been in development, including photovoltaic, wind turbine, and so on. This paper mainly researched on the photovoltaic, and integrated multiple functions of distributed power generation subsystems. Not only the model of photovoltaic system was simulated, composed of a photovoltaic module, a battery and a Z source inverter, but also a new cooling process for photovoltaic module was studied.Based on mathematical models, the output characteristic curves for the photovoltaic module and the charge / discharge curves of the battery were obtained. The advantages of using Z source inverter were compared with both boost and buck circuit inverters. The maximum power point tracking algorithm was implemented based on fuzzy logic control algorithm in combination with disturbance & observation design. In addition, the results of MPPT were simulated to confirm the high control precision and the fast response based on our algorithm.The two methods were studied to suppress the phenomenon in which the output power of a photovoltaic module decreases with its working temperature. Cooling water circulation and thermoelectric cooling modules were introduced to stabilize the temperature of the photovoltaic module. It was studied that the photovoltaic/thermal integration system through natural circulation could increase the output power of photovoltaic module. The thermal energy generated by photovoltaic module was collected by the circulation water, which increased the photoelectric conversion efficiency and the total system efficiency. It realized the combination of harvesting solar energy through photoelectric and photo-thermal conversions.Furthermore, the system through combining the photoelectric and thermoelectric generator was studied, in which the thermoelectric component plays a cooling process for photovoltaic modules. On the other hand, the system could generate the thermal electricity through using the temperature difference between the backside of the photovoltaic module and the environment. The system integration increased the photoelectric conversion efficiency and the total system efficiency. Two cooling ways made the working temperature of photovoltaic modules ramping slowly and achieved a good cooling performance. The design would provide a feasible solution for the future energy collection technology.