Design and simulation of a solar powered DC home with grid and battery back-up

摘要

In an attempt to provide a humble 100W electricity for a DC powered home in an incessant manner, this work deals with the design and implementation of a solar PV based home with uninterrupted power supply. The back-up power is supplied by the power grid and battery. In order to keep output voltage constant, the solar PV is cascaded with a buck converter which has a PWM modulator circuit in its feedback. A Proportional controller adjusts the Kp value which maintains the output voltage at a constant level by appropriately varying the duty ratio of the buck converter. The output of this buck converter is connected to a common DC bus. When solar DC power is unavailable, a reduced voltage 1Φ AC power grid (of 90V) supplies the home through a rectifier and a buck converter which maintains a constant 13.6V DC output. Battery also supplies power in cases when the other two sources are unavailable. Battery is charged either from solar PV or from the rectified AC. A microcontroller design ensures that this 100W DC home is supplied power for maximum amount of time at the minimum possible cost. The proposed scheme has been modeled and simulated in the MATLAB/SIMULINK environment. The test results show that the proposed design exhibits an excellent performance.