Solar-powered Battery Charging Based On High Efficiency Convertern And Maximum Power Point Tracking(MPPT)

With the increase in power demand and the global exhaustion of non-renewable energy,renewable energy resources such as solar and wind energy draws more international attention.Solar energy is completely natural and thus it is considered a clean energy source.It does not disrupt the environment or create a threat to ecosystems like the non-renewable sources of energy.It does not cause greenhouse gases,air or water pollution,environmentally safe,inexhaustible,noise-free etc.These advantages have made solar energy become one of the most promising green energy internationally.For standalone photovoltaic installations,both battery charging management and an efficient solar energy harvesting system are required.The lead acid battery charging control,which is a key feature,in terms of costs,in off-grid PV installations,must optimize both the charging time and the lifetime of the battery.To optimize the energy extraction in practice,the solar energy harvesting system needs a power conversion unit which performs an MPPT(maximum power point tracking)algorithm.In thesis provides a comprehensive design and implementation details of PV based lead acid battery charger system.The technique charges the lead-acid battery either in bulk charging mode or in float charging mode.This technique is implemented with the help of PV panel,perturb and observe Maximum Point Power Tracking(MPPT)algorithm,SEPIC converter and lead acid battery.The SEPIC converter uses capacitors for energy storage in addition to two inductors and was selected and designed for this research work because of its obvious advantages.An advantage of the SEPIC topology is that the capacitor can offer some isolation within the circuit.Its topology can be used to step-up or step-down the input voltage,making it ideal for battery storage applications.The other additional advantage is its non-inverting output,thus responds better to short-circuit output than other DC/DC topologies.Finally,for this thesis,a test platform was set-up to demonstrate the charging process of a typical lead-acid,deep-cycle battery.This analysis was carried out in two methods: Digital Simulation – using the MATLAB/Simulink simulation and the Virtual Simulation – using test Platform.The results show that the efficiency of the overall PV system is increased when the proposed MPPT algorithm is included to the system using PWM as a control scheme in the converter and fed into any autonomous load application.Simulation results validated the theoretical aspect of the concept.