Evaluating harmonic voltage distortion in load‐variating unbalanced networks using Monte Carlo simulations

Abstract

This study presents a new methodology for modelling and handling with aggregated harmonic loads and linear loads in the harmonic power flow analysis. This method, so-called variable load method, can be used in balanced and unbalanced systems and for deterministic and stochastic studies. The main types of harmonic loads and their participation coefficients inside the facility are estimated by inspection or based on usual values. In addition, a new type of load model that represents the load variation and minor loads is also defined based on field measurements, in order to build a more adherent harmonic load representation. A stochastic analysis, based on Monte Carlo simulations, is also performed. This sequence of steps makes possible to evaluate if the harmonic distortion has a significant probability of exceeding the limits set by standards because of load variations. This analysis is performed jointly with the bootstrapping method for obtaining the probability density functions of the voltage harmonic distortions. Tests on a real plant show that the proposed approach is able to represent measured data with high precision.

Assessment of the harmonic distortion in residential distribution networks: literature review

“…The coupled admittance matrix is a non-iterative approach that takes advantages of the coupled admittance model of electronic devices (Sun et al, 2007 Silva et al (2015) Tovilović & Rajaković (2015) Aljanad & Mohamed (2016) Bagheri et al (2016) Sharma et al (2016) Meyer et al (2017) Molina et al (2017) Tang et al (2017) Xiao et al (2017) Source: Authors These issues should be considered to obtain an accurate assessment in scenarios of large-scale penetration of multiple nonlinear loads:…”

“…Bearing in mind the same line of research, Silva et al (2015) presented a methodology to assess unbalanced distribution networks, considering load variation. Despite the simple applica-tion and the accounting of cancellation without diversity factors; it provides little understanding of the diversity effect and the harmonic interaction.…”

Circular regression models of modern harmonic producing sources

“…As it can be deduced from (14), the final circular regression model is represented by both cosine and sine terms. According to (12), the estimated mean direction is given as…”

“…Next, stochastic aggregate harmonic load models form a distinct family of methods focusing on application in stochastic harmonic propagation studies. Among research works involving development of such probabilistic models are [13,14]. These methods are best suited for simulating an impact of large bulk of aggregate lowvoltage load on medium-voltage networks with both composition and participation factor of loads usually modelled as random variables.…”

Avaliação do Índice de Estado Trófico e parâmetros de qualidade da água no reservatório da Usina Hidrelétrica de Sá Carvalho, Minas Gerais, Brasil

“…Nogueira et al (2015) relatam que os efeitos acumulativos do desmatamento repercutem em outros ecossistemas relacionados ao corpo hídrico. Já Silva et al (2015) destacam as alterações nos parâmetros físico--químicos da água; a elevação dos teores de metais tóxicos; e o incremento das concentrações dos nutrientes, com reflexos em toda bacia de captação.…”