PWM Switching Scheme Application In Controlled Stand-alone Photovoltaic System In Rwanda

This thesis covers study of a controlled stand-alone photovoltaic (PV) system suitable for a non-boarding school in off-grid areas in Rwanda. In this thesis, the Rwandan solar radiations and the temperature of different regions where collected and some were used for simulation.The system was studied at different stages:photovoltaic array V-I characteristics, maximum power point tracking, and control of boost converter (step-up converter) along with battery and DC load controlled for better energy management. The bi-directional converter control was used for charging and discharging of battery. A voltage droop control on dc bus was used as communication for control to react according to definition of control in energy management between the generating system, load and battery.Capacitor and resistance model is the battery used for simulation to demonstrate the idea in the thesis but for physical implementation, a physical battery can be used. The relationship of using capacitor in simulation to present physical battery can be related by scaling method where one second in simulation means30minutes in physical implementation.Perturb and observe method of Maximum power point tracking was used and PWM was used as the switching means to generate duty cycle while.PSCAD was used to do simulation.