MANAGEMENT OF ENERGY CONSUMPTION USING PROGRAMMABLE LOGIC CONTROLLERS (PLC'S)

The implementation of efficient energy systems is considered as one of the most important requirements in modern building. The purpose of these systems is to regulate energy consumption and meanwhile to reduce the negative impact on the surrounding environment through an efficient management of available energy resources, including renewable and nonrenewable resources. The integration of mains power supply with the solar power supply, besides other energy resources is a key element in designing the required energy management system. In this paper, the usage of Programmable Logic Controllers (PLC's) is proposed to control the energy consumed by various loads in the building based on real-time measurements of certain factors affecting the total amount of consumed energy. Hence, this paper presents a real time prototype design and implementation of an automated control system of mains electricity power distributed to various loads, using Allen Bradley MicroLogix 1100 Programmable Logic Controller (PLC). The PLC is programmed using ladder diagram for intelligent switching of both solar power supply and diesel generator power supply units. Also, it is programmed in order to prioritize the usage of the available solar energy as much as possible. The Rockwell Software Logix 500 is used for programming a PLC, running on a host computer terminal. For completeness, the control program results are compared with a hardware interfacing module.