Recursive real-time calculation of basic waveforms of signals

Abstract
Methods based on the Fourier technique are widely used for real-time determination of the basic waveforms of signals. The paper presents possibilities for the recursive implementation of these methods. Recursive algorithms have the same properties (frequency characteristics, response time) as nonrecursive ones, but they reduce the time of calculation very efficiently. The methods presented can be applied to the control and protection of electrical power systems.