The Intelligent Control On Stand-alone Photovoltaic Generation System

With the increasing value of population, the comsumption of energy is rising year by year,which leads to the energy crisis and environment problem even worse. As a new kind ofregenerative energy, the solar resource is not only abundant but also non-pollution. The greenenergy which is of great explored potentiality and utilized value is suitable to the growing demandof sustainable development. With the cost reduction of photovoltaic (PV) modules anddevelopment of PV technology, many countries through out the world are eagerly researching thesolar PV power generation technology. This paper deals with key problems，for example,controlling the battery charge and discharge properly and improving the energy utilization rate ofthe generation system by theory analysis.The background of the solar resource researching and the current situation of PV system areintroduced at first and then the components of PV system are discussed in this paper. Meanwhile,the paper introduced the working principle and electrical characteristics of the battery. Byexploring advantages and disadvantages of the various charging manner and control methods,proposed a new fuzzy control strategy which is based on voltage, temperature differential. Toprevent controller malfunction caused by external environment change and improve accuracy ofthe output, the control strategy judge battery working states by a fuzzy rule table and take the lightintensity and the temperature of environment into account. The battery’s service life and workingefficiency will be improved.To increase the energy utilization rate of the generation system, a new structure ofstand-alone photovoltaic system is proposed. The system contain PV modules、battery、DC/DCinverter、DC/AC inverter and the load of direct and alternating. DC/AC inverter adopt the way ofhigh frequency isolation. The system without an industrial frequency booster transformer will bemore simple and smaller. Finally, the proposed control methods are proved practicable by thesimulation results.