Analysis and Control of Temporary Overvoltages during Transformer Energization

The paper presents a new approach that assist power system restoration planning with regard to control of Temporary Over-Voltages- (TOVs) due to transformer energization. The frequency domain analysis in combination with analytical calculations is applied to find an optimum resonance condition. The analytical equations are based on sensitivity analysis for single frequencies and are extended to total sensitivity calculation. After an introduction to the phenomenon of overvoltages during power system restoration and harmonic resonance overvoltages, basic principles of their control are explained. Also an algorithm is introduced for the results evaluation of harmonic resonance studies where it is necessary to perform simulations. The objective is to find a minimum time after which the simulation runs of temporary overvoltages can be terminated using Short-Time Fourier Transform. Then the new algorithms are presented and demonstrated for a partial of 39 bus New England test system.

Keywords:

Harmonic overvoltages , Power system restoration , Transformer Energization