Impact of Harmonic Distortion on the Energization of Energy Distribution Transformers Integrated in Virtual Power Plants

Abstract

The virtual power plants have the characteristic of forming a conglomerate of electrical energy generating sources, among which the renewable energy ones stand out, where the energy supply performance is higher due to the management systems based on editable algorithms, in optimization of the distribution system with energizing of transformers minimizing the harmonic distortion of the supplied energy. The magnetizing current produced by an uncharged power transformer at the time of connection has extremely high values. These inrush currents generate a significant electrodynamic and thermal influence on the transformer windings and can determine the faulty operation of the protective equipment devices. In addition, since most power distribution systems are affected by harmonic distortion, the supply voltage applied at the energizing time has a non-sinusoidal waveform. In this way, the power management presented stands out for the quality of power supplied even in conditions of power generation with distortion imposed by inverters and potentially disturbing loads, with a predetermination of the peak value of the peak current and its harmonic spectrum under a distorted power supply voltage waveform. Starting from the transient state equations, along with a particular description of the value of the non-linear transformer core H-B and the core stacking factor value, the evolution of the burst current time is predicted accurately.