Design and implementation of a low cost fault tolerant three phase energy meter

This paper presents design and implementation of a microprocessor based intelligent three phase energy meter that measures accurate energy, even at the presence of harmonics. Moreover, if a fault occurs in any one of the potential transformer (PT) secondary circuits or the pressure coil in the measuring device, the unit can sense the fault and register the actual energy. Microprocessor provides a simple, accurate, reliable and economical solution of these problems. A framework of hardware circuitry and assembly language program for evaluation of energy values have been given and the problems which should be paid attention to execute the proposed algorithm using microprocessor has been discussed. Illustrative laboratory test results confirm the validity and accurate performance of the proposed method in real-time.