INTRODUCTION OF AN ADVANCED METHOD FOR TESTING OF BATTERY CHARGE CONTROLLERS FOR OFF-GRID PV SYSTEMS

摘要

With the fast-growing energy demands of today's world, the Sun as a massive clean energy source can compensate the predictable energy shortage in near future. Since solar irradiance is only available in some hours of the day, efficiency of a solar energy system is of high importance. In this matter, the advantage of considerable amount of energy that could be achieved if the sun could radiate all day long or there was no cloud shadowing, cannot be ignored. Since this situation is unreal, in solar off-grid systems a storage system and most commonly a battery system is considered. Besides, installing a Maximum Power Point Tracking (MPPT) allows the system to produce higher power in the low irradiation hours of the day or wintertime in comparison to systems without MPPT. This work focuses on the most usual approach for backup storage of an off-grid solar system, which consists of a battery and a battery charge controller. In this study, a test process will be introduced to be able to analyze these devices' performance and efficiency. Although this has been done before for PV inverters combined with Maximum Power Point Tracking (MPPT), it requires a different approach to implement efficiency analysis on charge controllers. Furthermore, by testing and comparing of various MPPT devices with different tracking algorithms advantages and disadvantages of tracking algorithms will also be shown.