Fast and accurate grid signal frequency estimation is a very important issue in the control of renewable energy systems. Important factors that influence the estimation accuracy include the A/D converter parameters in the inverter control system. This paper presents the influence of the number of A/D converter bits b, the phase shift of the grid signal relative to the time window, the width of the time window relative to the grid signal period (expressed as a cycle in range (CiR) parameter) and the number of N samples obtained in this window with the A/D converter on the developed estimation method results. An increase in the number b by 8 decreases the estimation error by approximately 256 times. The largest estimation error occurs when the signal module maximum is in the time window center (for small values of CiR) or when the signal value is zero in the time window center (for large values of CiR). In practical applications, the dominant component of the frequency estimation error is the error caused by the quantization noise, and its range is from approximately 8×10-10 to 6×10-4.

JO - Metrology and Measurement Systems L1 - http://rhis.czasopisma.pan.pl/Content/90258/PDF/Journal10178-VolumeXXI+Issue3_05.pdf L2 - http://rhis.czasopisma.pan.pl/Content/90258 IS - No 3 EP - 432 KW - photovoltaic system KW - frequency estimation KW - signal processing KW - A/D converter KW - control of power system ER - A1 - Mroczka, Janusz A1 - Borkowski, Józef A1 - Kania, Dariusz PB - Polish Academy of Sciences Committee on Metrology and Scientific Instrumentation JF - Metrology and Measurement Systems SP - 423 T1 - Influence of A/D Quantization in an Interpolated DFT Based System of Power Control with A Small Delay UR - http://rhis.czasopisma.pan.pl/dlibra/docmetadata?id=90258 DOI - 10.2478/mms-2014-0036