Overview on Approaches for Modeling Uncertainties in the Harmonic Load-flow

A. A. ROMERO; H. C. ZINI; G. RATTA

Asunción

Simposio; International Symposium on Power Quality; 2011

Universidad Nacional de Colombia

Due to the increasing use of power electronic devices and nonlinear loads (NLLs), harmonic distortion is a growing problem in all the power systems (PS) around the world. In this context, several methods for the computational analysis of the harmonic load-flow (HLF) in PS have been developed. These approaches allow for the harmonic distortion estimation at each bus of the PS, when NLLs, which are the harmonic sources, are distributed in the whole network. In the HLF analysis issue, there are some widely accepted deterministic formulations. However, harmonic distortion in PS is a time-varying phenomenon because both linear loads (LLs) and NLLs change all the time in a non-predictable way; moreover, network configuration also varies. This consideration makes the HLF calculation a mathematical problem which must be able to model uncertainties associated with the input data. To model this involved uncertainty some approaches based on the probability theory, and others founded in the fuzzy sets and the possibility theories have been proposed. Therefore, the aim of this paper is to bring an overview on these approaches. In particular the main HLF formulations in the probabilistic and possibilistic frameworks will be introduced. Finally some numerical comparisons will be developed in order to clarify some here exposed concepts.