Techno–Economic Viability of the Hybrid Solar (PV)-AC Utility Interfaced Power System for Rural India

A hybrid solar Photovoltaic (PV)-AC utility interfaced power generating system has been developed for domestic use. The system consists of a photovoltaic array (installed on the structure of the roof), an intelligent power controller and an inverter with battery as an energy storage device. The system works in such a way that it utilises maximum power from the PV source, converts it into useful AC power for household critical loads. The variation in PV power is supplemented by a grid power source integrated with the PV source. The system finds wide application in rural sectors where the conventional source of supply has been restricted and further expansion of utility (grid) supply is not possible due to various technical and economic reasons. Thus it saves grid power and reduces the overburdening of power on grid lines. The technology of solar energy conversion into useful AC power through push-pull configured transistorised inverters involves the PWM strategy which produces a very near sine wave output with minimum THD, leading to a highly efficient system. The system has been designed for 300 W power supply for critical loads. The simulation for the generation of PWM pulses and the computation of THD value has been carried out. Performance of the system was tested under various abnormal conditions like grid failure, low or no sunshine conditions, etc. The system provides optimum use of solar PV power with environmental benefits.