Quality of energy produced in renewable energy systems has to be at the high level specified by respective standards and directives. One of the most important factors affecting quality is the estimation accuracy of grid signal parameters. This paper presents a method of a very fast and accurate amplitude and phase grid signal estimation using the Fast Fourier Transform procedure and maximum decay side-lobes windows. The most important features of the method are elimination of the impact associated with the conjugate’s component on the results and its straightforward implementation. Moreover, the measurement time is very short ‒ even far less than one period of the grid signal. The influence of harmonics on the results is reduced by using a bandpass pre-filter. Even using a 40 dB FIR pre-filter for the grid signal with THD ≈ 38%, SNR ≈ 53 dB and a 20‒30% slow decay exponential drift the maximum estimation errors in a real-time DSP system for 512 samples are approximately 1% for the amplitude and approximately 8.5・10‒2 rad for the phase, respectively. The errors are smaller by several orders of magnitude with using more accurate pre-filters.

JO - Metrology and Measurement Systems L1 - http://journals.pan.pl/Content/90377/PDF/10.1515-2016-0013-paper_02.pdf L2 - http://journals.pan.pl/Content/90377 IS - No 1 EP - 26 KW - control of power KW - grid signal KW - amplitude and phase estimation KW - renewable energy KW - interpolated DFT KW - maximum decay side-lobes windows ER - A1 - Borkowski, Józef A1 - Kania, Dariusz PB - Polish Academy of Sciences Committee on Metrology and Scientific Instrumentation VL - vol. 23 JF - Metrology and Measurement Systems SP - 13 T1 - Interpolated-DFT-Based Fast and Accurate Amplitude and Phase Estimation for the Control of Power UR - http://journals.pan.pl/dlibra/docmetadata?id=90377 DOI - 10.1515/mms-2016-0013