Design, control and performance analysis of DC-DC boost converter for stand-alone PV system

Solar energy is considered as one of the most reliable, daily available, and environment friendly renewable energy source. All PV modules provided in markets gives 12 or 24V (2 up to 5 A) but load requirements need higher voltages so boost converter is needed. DC-DC converters are applied between the source and the load as power conditioning unit to regulate and boost up photovoltaic voltage to desired output voltage. Duty cycle of the converter needs to be adjusted to obtain a constant level of voltage. In this paper, the complete power system consists of a module of solar cells, a DC/DC boost converter with its duty cycle controller and load (resistive or dc motor). This system is modeled and simulated in MATLAB SIMULINK. But, solar module's output is uncertain and complex. So firstly, a laboratory model of boost converter is designed, implemented and tested for operation and the experimental results are obtained. Open loop simulation results are compared with the experimental results to verify the effectiveness of the simulated model. The model is simulated with constant dc input and with disturbance at the input voltage. Finally, closed loop control is presented using proportional-integral (PI) and fuzzy logic control (FLC) to control duty cycle of DC/DC converter. The effectiveness of FLC is verified through simulation analyses, highlighting the fast response and good dynamic of the system.