Further Generalization of the Low-Frequency True-RMS instrument

Abstract

In this paper, it is shown that the use of random uniform dither in harmonics measurement can significantly shorten the word of applied A/D converter and shorten the word of applied base function (sine and/or cosine), stored in memory, without accuracy loosing. This fact enables design of simple instrument for harmonics measurement. It is proven theoretically, by simulation and by experiment that 6-bit dithered A/D converter word, 8-bit dithered base function word, and 6 x 8 (14-bits) multiplier word assure measurement of 16 harmonics (16 sine and 16 cosine components) with 13-bit accuracy. Putting n such simple devices in parallel it is possible to measure n x 16 harmonics simultaneously. The measurement of 1 x 16 harmonics is realized in the small PLD chip.

Influence of Wilbraham-Gibbs Phenomenon on Digital Stochastic Measurement of EEG Signal Over an Interval

“…Simulations are performed with simulation model implemented in Matlab and VisualC and verified in previous extensive experimental verifications [16][17][18][19]25]. Measurement interval of 20 ms is chosen, because the developed instrument supports this interval (fundamental frequency of 50 Hz).…”

“…this quantization step is compared with previously found DSM errors. It can be noticed that DSM In the DSM approach, if there are no signal discontinuities, although measurement uncertainty can also be lowered by choosing an A/D converter with higher resolution, there are two other techniques of lowering measurement uncertainty [16][17][18][19][20]25]:…”

“…Several prototype and small-series commercial instruments have been realized and calibrated, and their measurement uncertainty can be extremely low [16][17][18][19]. The approach of those methods was named Digital Stochastic Measurement (DSM) and these instruments were named Digital Stochastic Instruments.…”

“…The method and the predicted uncertainty for 50 harmonics are validated in [18] by simulation and experiments using the sampling frequency of 250 kHz per channel. In [19] of this method to be applied for measurement of harmonics of any stationary signal. Improvement of this method is presented in [20], for the cases when fundamental frequency drifts from its nominal value as is the case with real power grid signals.…”

Design and Implementation of a Novel Complete Filter for EEG Application on FPGA

“…So these papers have proposed a different method apart from FFT which is known as stochastic measurements [1,2], instead of spectral analysis they have shown their affinity with voltage and current harmonic analysis. In this study [3] they have designed the parameter of stochastic analysis with harmonic estimation for the direct current portion and being converged until 49 harmonics.…”