EXTERNAL LIGHTING SYSTEM WITH PRIORITY POWER SUPPLY FROM DC VOLTAGE SOURCE

Abstract

This paper proposes an outdoor lighting system with priority power supply from a battery charged during the daytime by an autonomous photovoltaic station. The developed system is designed to reduce the electrical energy consumption for lighting from centralized power grid.Automatic control of energy flows between the battery, centralized power grid and lighting devices with priority for power supply from the battery is realized on the basis of two electromagnetic relays PK-1P and PK-2P. The centralized power grid in this system is used as reserve power source.The time delay required to avoid PK-1P relay returning to its initial state during triggering of PK-2P relay is provided by a 260 μF capacitor connected in parallel to the PK-1P relay electromagnet.The system is started automatically due to photo relay that is triggered when the light level decreases. The Kijo JDG 12V 65Ah GEL battery is recharged by photovoltaic system built on a 120P/12 silicon photovoltaic module and a SLC NR2420A PWM battery charge controller. A KONNWEI 2000W standalone inverter is used as a converter of 12 V DC battery voltage to 220 V 50 Hz AC.The developed system was implemented at the Kherson National Technical University to illuminate the courtyard of the 1st academic building. It has been experimentally clarified that when two 30 W LED spotlights are used as lighting devices the system provides power supply from the battery during 7-8 hours reducing the electrical energy consumption from the centralized power grid.