Development Of Solar Energy Storage Technology

The research of solar energy storage technology is a crucial link in stand-alone photovoltaic power system. Because the solar photovoltaic conversion is effected by changes of sun which is the raw material, the working process presents nonlinear working state along with seasonal evolution, environment temperature, and alternating day and night. This phenomenon effects energy utilization of stand-alone photovoltaic energy systems and energy storage. This thesis makes a deep research of storage technology based on the stand-alone photovoltaic power systems. The following contents are mainly studied in this thesis:1. The overall scheme argumentation. In this thesis, the overall scheme and the main components of stand-alone photovoltaic energy storage systems are analyzed firstly, and the integraed system of solar array MPPT, charging control and temperature compensation based on AVR MCU is expounded.2. Analysis of solar battery working principles and characteristics. The characteristics of charging and discharging are expounded, and the factors which affect the performance of battery capacity, life span, and resistance are analyzed. Independent photovoltaic power generation system to complete energy storage based on the batteries’performance characteristics.3. Research on battery control technology. Compare and research of all sorts of battery charging methods. For the particularity of the charging batteries in the PV system, we put forward a reasonable control method for strategy charge. Not only complete the maximum power point tracking of photovoltaic array, but also guarantee the normal working life of the battery.4. Hardware design and research of system. Through sampling of the voltage and current signals of the PV array to analyzes its maximum output power point. Calculate the battery capacity through the measurement of battery voltage, current and electrolyte temperature. At last, real-time displaying and storing of system results are done in host computer through RS232 communication interface between MCU and host computer.5. Design of software, including software design of power point tracking and charge-discharge control, RS232 communication. And the control interface for host computer based on MCGS is completed.6. System test and result analysis. Real-time measurement is done using this system. The experimental data shows that the detector has higher reliability. Meanwhile, the power point tracking is finished.With the extensive application increasingly of solar photovoltaic power generation, the research of efficient photovoltaic energy storage system has important economic and social benefits. At present, the domestic research is still behind developed countries. In this thesis, the research has played a positive role in the domestic solar storage technology.