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.
