Quantificação das perdas técnicas da distribuição em condições distorcidas

Abstract

Palavras-chave: perdas de energia, sistemas de distribuição, perdas técnicas, cargas não lineares, perdas harmônicas.

Loss Analysis Due to Influence of Harmonics in a Distribution System

“…In addition, another source of harmonics in the power grid are photovoltaic sources and inverters, with significant third and fifth order harmonics. In transformers, when operating with low or empty current, the magnetization current predominates, having third order harmonic content [3], especially during the night, when there is a low load and high voltages. The presence of these charges results in an electrical system with distorted conditions, and these effects directly affect it, either in distribution or in equipment.…”

“…This heating can affect the coils, due to skin effect, where with increasing frequency the current tends to circulate on the conductor's surface. As presented in [3], the presence of harmonics components increases the effective value of the current causing problems to the equipment of an electrical network. In addition, his work highlights the effect of these disturbances on the increase in energy losses in distribution and transmission, with a detailed look at losses in conductors also due to the skin effect.…”

“…In such a way, the Joule losses are calculated from the sum of the losses due to the fundamental current and the losses due to each harmonic. The mathematical procedures on this subject are presented in detail in [3]. Note that considering R constant is a rough approximation.…”

“…The study was based on what was developed in [3] and [12] regarding the increase in technical losses due to harmonics. The considerations on photovoltaic systems found in [11] and [13] were added, expanding the calculations for odd harmonic spectrum of up to nineteenth order and performing them for a LV system with 390 buses.…”

“…With the data collected, a routine was developed in MATLAB ® integrated with OpenDSS in such a way that the power flow was calculated for three cases: cold day (1), mild day (2) and hot day (3). For each of these cases, the calculation was restarted, and the respective load shape obtained by fuzzy logic were inserted.…”