Calculation of currents resonance at higher harmonics in power supply systems based on wavelet packet transform

Defining the possibility of resonant modes onset in power supply systems (PSS) is a relevant task in selection and validation of VAR compensators (VC). At the current resonance negative consequences take place: supplemental heating of conducting parts, overload with the consequent outage of static capacitor batteries (SCB), excessive heat of transformer windings and a core. Existing practices to determine the boundaries of non-sinusoidal modes acceptance are developed for stationary modes and they use effective values of currents and voltages defined by the Fourier transform (FT). The methods of mathematic modeling allowed the frequency decomposition of the signal to be performed using the mathematical apparatus of the wavelet packet transform. This decomposition into the frequency components allowed the time intervals of HH in PSS to be determined. This paper presents the modification of existing algorithms and techniques based on packet wavelet transform. The validity of the presented technique was confirmed by a numerical experiment.