AM Modulation Signal Estimation Allowing Further Research on Sources of Voltage Fluctuations

This article presents the preliminary research results on a novel method of amplitude modulation demodulation that allows estimation of the modulating signal at a frequency higher than that of the carrier signal. The need for a new method from the perspective of research on sources of voltage fluctuations is first explained. Then, a comparison is carried out between the estimation of the modulating signal based on the currently used demodulator in the IEC flickermeter signal chain, the finite-impulse response Hilbert filter, and the proposed method with the carrier signal estimation. The correctness of the recreation of the frequency of the modulating signal, as well as, the signal amplitude and shape were considered in the comparison. The influence of the deformation of the carrier signal on the estimation error of individual demodulation methods was investigated. The metrological interpretation of the results obtained from the numerical simulation and experimental research is discussed, and the conclusions are presented.