Summary
2007 International Symposium on Nonlinear Theory and its Applications
2007
Session Number:17PM2-A
Session:
Number:17PM2-A-3
An Analysis of Second-Order Sigma-Delta Modulator and its Application to AC Load Monitor
Keita hayashi, Hisato Fujisaka, Takeshi Kamio, Kazuhisa Haeiwa,
pp.59-62
Publication Date:2007/9/16
Online ISSN:2188-5079
DOI:10.34385/proc.41.17PM2-A-3
Summary:
We analyzed the behavior of discrete-time second-order sigma-delta modulators in state-space. As a result of the analysis it is found that the sigma-delta modulated signals never contain a certain sub-sequence set which changes depending on the polarity of the inputs to the sigma-delta modulator. Thus, by detecting the subsequences we can determine whether the input is positive or negative. We applied the sub-sequence detection to the measurement of average current and power factor for linear AC circuits with sinusoidal power sources. The error of the power factor measurement is less than 0.1.