Analysis and Development of Digital Sampling Wattmeter Components for Precise Electric Power Measurement

Precise power measurement is usually done in national metrology institutes. In recent years researchers have devoted substantial time toward a measurement of power under non-sinusoidal conditions, especially in power grids because of renewable energy increase. The challenge is not only in measuring power at 50 Hz, but also measuring harmonics and inter harmonics at needed precision. In this paper, a focus on generation and measurement of power and energy measuring methods for sinusoidal conditions will be given. The paper will divide power and energy measuring instruments and methods to several key components and will give overview of each of those system components and their calibration. This will include power definition standards, power calibrators, current shunts, voltage dividers, digital voltmeters, data analysis, correction algorithms and uncertainty analysis. Moreover, preliminary testing results of digital sampling wattmeter developed at the Faculty of electrical engineering and computing will be presented.