Real time implementation of a single stage converter based solar-wind hybrid system

Abstract

Increasing environmental pollutions, lack of power in remote places and demand for more energy makes us to seek new energy sources. Wind and solar hybrid energy have being popular ones owing to abundant, complement nature, ease of availability and convertibility to the electric energy. For hybridizing solar-wind system DC-AC or separate DC-DC converters are used one for each source. They will be connected to AD-DC or common DC-DC link to feed the loads according to the requirements. Such separate converters have the high count of elements and makes the system bulky and complex. This paper presents the performance comparison between separate cuk and buck converter and a single stage cuk-buck converter that integrates solar-wind renewable energy with battery backup using MATLAB/SIMULINK, to make best use of their operating characteristics and to achieve compactness and higher efficiency. FPGA controller is programmed for maintaining constant power at point of common coupling. An embedded controller based online state of charge estimation and battery charging system to suitably sink or source the input power based on the load demand is also carried out. Real time implementation of solar system with 1.5kW peak power, wind system with 1.4 kW and 48V, 200 Ah Lead-Acid batteries for powering 1200 Watts DC load is carried out to validate the theoretical approach.