Research And Design Micro Independent Photovoltaic Power System Based On VRLA Battery Energy Storage

Facing the depleted traditional energy sources and serious environmental pollution, stand-alone photovoltaic power system has become the main way to solve the energy crisis and improve the environment. The battery as a energy storage devices of the independent photovoltaic power generation systems, its energy storage officiency can directly affect the efficiency and cost of the whole system. For extend the use of life and the efficiency of energy storage of the battery, the corrected amper-hour method and EMF method was used to to predict the capacity of the storage battery, and proposed three-stage optimized charging method to improve the battery charging, it has a more accurate estimation of SOC of the battery and improve the charging efficiency of the battery.Firstly, the basic principle of photovoltaic power generation system and the the research status of the technology of photovoltaic power generation was be introduced in this paper. Has made a detailed analysis about the categorization and the composition and the working principle of photovoltaic power generation system. Discussed and selected the Maximum power point tracking methods of photovoltaic battery.Aim to achieve the anticipated target of the designed ndependent photovoltaic power generation system, give a detailed analysis of how to calculate the output power and the capacity of the battery. In this paper we corrected the troditional Ah counting method and combine with the equivalent electromotive force method to estimate SOC. This method was experimental and the experimental results were analyzed and discussed. Also give a detailed analysis to battery charging control method, and optimized the efficiency of energy storage by using combination of optimal a three-stage charging method and Terminal voltage balance method.Chip TMS320F2808was used as the master controller. Design of the system hardware circuit including DC/DC converter circuit, the driver circuit, the sampling circuit, A/D conversion circuit and the terminal voltage balancing circuit.Also have a design for system control of software to entrue the hardware circuita can play its due role, such as control the optimal three-stage charging method and avoid over discharge of the battery.