CONTROL DEVICE OPTIMIZING COMPUTING INPUT SAMPLE OF DATA WITH DISCRETE FOURIER TRANSFORM ALGORITHM

摘要

An automatic control device (1) that comprises input means (21, 24) forinputting measured values (7) of cyclic voltage and/or current; computingmeans (21) for computing a parameter based on said values of voltage and/orcurrent, and for comparing the computed parameter against a predefinedcondition; and initiating means (21, 23) for initiating a control function inresponse to the parameter meeting the predefined condition. The input means(21, 24) of the control device are arranged to input a predefined number ofsamples per one cycle; and said computing means (21) are arranged to computethe parameter with a discrete Fourier transform algorithm optimized based onfixed coefficients related to said predefined number of samples per cycle. Thecontrol device and the corresponding control method provide a significantlyfaster response time than the earlier general programmed solutions withoutincreasing the related costs as much as the conventional digital signalprocessors.