Design and implementation of a microprocessor-based intelligent electronic meter

This paper presents the design and implementation of a microprocessor-based intelligent electronic measuring apparatus. The meter can measure instantaneous values of voltage, current, and power of electrical power distribution systems. A novel random asynchronous sampling technique that samples voltages and currents at predetermined intervals is exploited so that circuit complexity can be reduced. Furthermore, the accuracy of the meter is improved significantly by compensation of phase shift error due to the current transformer (CT). Moreover, the A/D quantization error is compensated for low current measurement. A prototype including CT is built to verify the theoretical analysis and examine the performance of the proposed system. The proposed meter can be used as a universal electrical meter for both local power consumption indication and computerized power management systems