In developing countries, many areas are not supplied with electricity due to lack of electric power infrastructure, and many others are suffering from unstable power quality and frequent power outages. As an alternative, power supply using renewable energy, such as solar, wind, and small hydro power, is being activated. Among these, the most widely used source is photovoltaic power generation system, which is easy to install and maintain. In developed countries where power supply is smooth, grid connected photovoltaic systems that use conventional electricity together are generally used for the purpose of reducing electricity bill. However, in developing countries, because conventional electricity supply is unstable, independent solar power generation systems using batteries are mainly used. Among these, a solar panel is a semi-permanent product that can be used for more than 20 years, whereas a typical battery is a consumable with a maximum life span of less than five years, accounting for most maintenance cost of solar power systems. In addition, in the case of a lead storage cell, which is readily available in developing countries and therefore is most widely used, lifespan has been drastically reduced depending on environmental conditions such as pre-charge method, temperature, and humidity, which frequently makes it replaced in six months. For these reasons, management methods to extend lifespan of lead storage cell have become an important research topic. In this study, a voltage level was set as a measure value to identify and manage the characteristics of charging and discharging of lead storage batteries, and standardized discharge curves were created using LED lamps that consume the most stable power. Based on this, the discharging characteristics for different kinds of DC and AC products were identified. Also, the proper isolation voltage level to extend the battery lifespan was verified. The study will be used to design an optimized solar power system along with the further study on charging efficiency of solar power systems in developing countries.
Introduction
Research Methods and Materials
Results and Discussion
Conclusion