Design of an automatic solar lighting system

Today, the worldwide research trends are heading towards producing environmental friendly outcomes. Thus, today the electricity is mostly generated from renewable sources such as sunlight, wind, tides and other to reduce dependency on non-renewable sources like hydroelectrics, fossil fuels and others. This paper presents an innovation of the automatic lighting system with the solar as a source of the system. Charger controller circuit is necessary to cut off the current of the rechargeable battery when reaching its maximum voltage. Dark-on relay circuit functions as an automatic switch to the light so that the light will be automatically turned on when there is no light or at night. Otherwise, the light will be turned off. The system can be applied to the room light, outdoor light, corridor light, spotlight or streetlight. The system is low cost and beneficial for home usage to save electricity bills and when the occupants are absent for relatively long period of time.Keywords: renewable energy; solar energy; green technology; sustainable; dark on relay; automatic lighting system; analog electronic circuits; LD

Single Stage String Inverter for Gridconnected Photovoltaic System with Modified Perturb and Observe (P&O) Fuzzy Logic Control(FLC)-based MPPT Technique

This paper presents an implementation of Single-phase Single stage String inverter for Grid connected Photovoltaic (PV) system. The proposed system uses Modified Perturb and Observe (P&O) algorithm implemented using Fuzzy Logic Control (FLC) as Maximum Power Point Tracking (MPPT). The inverter is designed for 340W system using two series of STP170s24/Ac PV modules. The MPPT unit keeps tracking the maximum power from the PV array by changing the modulation index and the phase angle of inverter’s output voltage. The simulation model is developed using Matlab/Simulink to evaluate the performance of the converter. Selected experimental results are also presented in this paper