Fast steady-state technique for harmonic analysis

The authors describe an alternative method for harmonic analysis in electric networks. The steady state solution is found in the time domain using an interactive Newton algorithm, and a Fourier analysis is applied on the magnitudes of interest. The search for the steady state solution is as follows: first, one or several cycles are simulated in the time domain beginning from arbitrary initial conditions; then, the periodicity condition is checked. If it is not satisfied, the Newton algorithm is applied, and new initial conditions are found, from which a new period of integration begins. After several iterations, steady state initial conditions should be found and steady state waveforms obtained. Finally, a Fourier analysis is carried out and the harmonic spectra of the variables of interest calculated. This method has been implemented in the program FASST