Study on the Off-grid Type Wind-solar Photovoltaic Hybrid Generating System

An off-grid wind-solar photovoltaic hybrid generating system of electric vehicle was designed on the basis of typical climatic conditions of Tangshan city in North China. The power generation and electric vehicle charging characteristics of the system under different seasonal temperature was studied. The results indicate that the wind and solar hybrid power output of summer is about 10% higher than the power output in the same period of winter. In addition, the power generation efficiency in summer is higher also. Because the wind velocity is smaller in urban areas, more than 85% generating capacity is provided by the photovoltaic power generation system. The charge-discharge property of lithium ion batteries at different temperatures in the laboratory and in the electric vehicles was tested respectively. Results show that the LIB pack has the best charge-discharge property at 25 degrees C than that at other temperatures. When the temperature is below 5 degrees C the performance of LIB pack is worse. The Module temperature and average monomer voltage of lithium ion batteries in the electric vehicles run stably and effectively in spring and autumn, but the performance decline in winter and summer.