Energy management by means of PLC for a solar powered ultra-capacitor streetlight system

Abstract

This paper presents the design of an energy management programmable logic controller (PLC) control program for a solar powered ultra-capacitor and battery powered streetlight system. A PLC is used to control the flow of energy between an ultra-capacitor bank and a deep-cycle battery bank for a solar powered streetlight system. The purposes are to increase the efficiency of the complete solar powered system and to prolong the lifetime of the battery bank, since deep-cycle batteries normally used in solar electrical systems, generally have low efficiencies, have a limited amount of charging and discharging cycles, have long charging times and are temperature sensitive. The designed operational diagram as well as a functional block diagram of PLC control program is presented. The results of five different scenarios pertaining to the functionality and use of the energy between the ultra-capacitor bank and deep-cycle battery bank are presented in this paper