Design of a microprocessor based prepaid energy meter with inbuilt communication technology

Abstract

This project presents a design of a microprocessor based prepaid energy meter which is equipped with GSM communication technology. This energy meter has features which conveniently addresses the above stated problems; thus, allowing consumers to comfortably purchase energy units remotely. It also has features that allow utilities to detect felonious tampering activities in real-time as well as transmit consumer notifications. This improved prepaid energy meter design is also proven to be of low-cost making it a suitable choice of replacement for most Ghanaian Utilities such as Electricity Company of Ghana (ECG) and Northern Electricity Distribution Company (NEDCo). Prepaid energy meter is a new concept in the measurement of electrical energy consumption on periodic basis. This method of measurement and data collection discards the conventional method of taking the meter reading manually. This project report presents a GSM based prepaid energy meter credit loading system comprising two microcontrollers, a single phase energy meter IC and a Global System for Mobile Communication (GSM) modem. The energy consumption is calculated using the output pulses of the energy meter chip and the internal counter of microcontroller (ATmega32). A microcontroller (ATtiny13) is used as a smart card and the numbers of units recharged by the consumers are written in it. A relay system has been used which either isolates or establishes the connection between the electrical load and energy meter through the supply mains depending upon the credit present in the smart card. Energy consumption (kWh), maximum demand (kW), total unit recharged(kWh) and rest of the units (kWh) are stored in the ATmega32 to ensure the accurate measurement even in the event of an electrical power outage that can be easily read from a (16x2) LCD. As soon as the supply is restored, energy meter restarts with the stored values. Cost analysis of the design resulted in GH₵264.00. Low power consumption, greater accuracy, greater convenience, easy maintenance and affordable cost were achieved by the design.