Ivan Nunes Santos

Methodology for estimation of harmonic hosting

The increasing penetration of distributed generation with non-linear characteristics demands a clear methodology for determining the amount of generation that can be connected to the system without deteriorating the performance. This paper proposes a methodology for determining the hosting capacity regarding harmonic distortions. To exemplify an application of the proposed procedure, a simple case study is performed and analyzed.

Critical Analysis of the Current and Voltage Superposition Approaches at Sharing Harmonic Distortion Responsibility

Faced with the guidelines contained in documents approved by the National Electric Power Agency PRODIST - Module 8, amongst other indicators of electric power supply quality, the harmonic distortions appear as an important issue. The mentioned regulation takes into account specific matters such as definitions, measurement procedures, benchmarks, etc. Focusing the subject of voltage distortions and the establishment of approaches to determine the responsibility for possible violations of given limits emerges as an important task. This research topic has been taken into account by the literature and a few procedures to characterize the responsibility of a given distortion level due to supplier and consumer has been proposed. The most widespread solutions are based on frequency domain superposition principles. Having this in mind, the current paper conducts a critical analysis performance of the superposition methodology throughout two possible ways of dealing with the subject. The first uses the current contributions and the other by focusing the voltage harmonic found at a given busbar. The studies highlight that the current procedure do not lead to consistent results whereas the voltage method seems to provide a promising manner of dealing with the identification of the harmonic distortion responsibility.

Critical evaluation of the performance of the method of harmonic power flow to determine the dominant source of distortion

In many guidelines contained in documents approved by electrical regulation agencies, harmonic distortions appear as an important issue among other indicators of electric power supply quality. In general, these standards consider specific aspects, such as definitions, measurement procedures, and benchmarks. Overcoming challenges related to voltage distortions and establishing ways to determine the responsibility for possible violations of given limits are also important matters. The literature describes procedures to characterize the major responsibility among the agents involved (supplier and consumer) or, in a more advanced way, the individual contributions. One of the simplest and most widely used methodologies for identification of the major source of harmonics consists of determining the direction of harmonic power flow by comparing the fundamental and harmonic power signals. Most commercial power quality measuring equipment has the ability to quantify fundamental and individual harmonic powers. However, this study shows the weaknesses of this method. Theoretical analyses, as well as computational and experimental studies, were performed for a hypothetical electrical arrangement. The electrical network was investigated under different operating conditions, and the power harmonic approach was used to determine the dominant harmonic source. The results were then used to evaluate the effectiveness of the methodology to find the correct response.

Determining the harmonic hosting capacity of PV sources for a university campus

The paper address the concept and application of hosting capacity study methodologies to harmonics caused by photovoltaic panels (PV) connected to low-voltage (LV) at an university campus. The analysis of the insertion of new distributed generation technologies, such as photovoltaic panels in the distribution system of this campus was carried out initially via analytical processes, and later by computer simulations in steady state simulation-based programs, such as the SKM-PTW. The power quality impacts are analyzed and discussed aiming to make recommendations to the university regarding a recently approved project to implement additional PV generation across the entire campus and transform it into a more sustainable system.

Applying the Superposition Procedure for the Harmonic Sharing Responsibility between Renewable Energy Power Plants and the Network

Abstract The increasing penetration of renewable energy sources with nonlinear characteristics, such as wind and photovoltaic power plants, demands a clear procedure for harmonic sharing responsibility between this new kind of generation and the network at the point of common coupling. In fact, there are in literature many procedures regarding the determination of responsibility for violating harmonic distortion limits. Among these proposals, the methodology based on the superposition principle has been one of the most promising procedures. In this context, the present paper is focused on a procedure that applies the superposition methodology to find the harmonic sharing responsibility between a wind power plant and the utility network. To exemplify this application, a case study is performed and analyzed.

Performance analysis of the current summation law in wind generation

Sources of alternative energy are gaining space in the worldwide electric energy sector at an ever-increasing rate, and especially in Brazil, where wind energy has been hitting new records of MW of generation. As already known, this source of energy possesses non-linear characteristics, which therefore means it is a potential generator of harmonic disturbances. In this manner, a clear procedure for the estimation of harmonic current values at the coupling point of unit generators becomes necessary. The summation law is widely used for calculating the harmonic current at the network connection point with renewable generation. The summation is performed for each harmonic order of the currents arising from the individual wind turbines. In the present study, the procedure for current summation will be applied to a wind farm case study.

Exploring the concept of hosting capacity for harmonic distortions assessment

The increasing penetration of renewable/distributed sources with non-linear characteristics demands a clear methodology for determining the amount of generation which can be connected to the system without deteriorating the performance (the “hosting capacity”). This paper proposes a methodology for determining the hosting capacity regarding harmonic distortions. To exemplify an application of the proposed procedure, a simple case study is performed and analyzed.

A proposal of methodology for the assignment of responsibilities on harmonic distortions using the superposition principle

This paper presents a strategy for the sharing responsibility assessment regarding harmonic distortion. Such technique covers the harmonics that they are present at the point of common coupling between the utility and a consumer. This proposal is based on classic superposition principle. Since there are some limitations to apply this principle in a real system, this work proposes an alternative way. That is, it is proposed here the utilization of a dominant impedance in order to reach the correct harmonic sharing responsibility.

Performance Evaluation of Harmonic Current Summation Law Applying to the Wind and Photovoltaic Generation

The increasing penetration of renewable energy sources with nonlinear characteristics, such as wind and photovoltaic power plants, demands a clear procedure for harmonic current estimation on point of coupling of these sources. The summation law is widely used to estimate the total harmonic current in a coupling point between the network and a distributed generation. This is done for each harmonic order and the analysis is performed by mean harmonic currents provide by an individual wind turbines. In this work, the summation law will be analyzed by a wind park case study.

AVALIAÇÃO DE DESEMPENHO DE MODELOS COMPUTACIONAIS REPRESENTATIVOS DE PAINÉIS FOTOVOLTAICOS

Este trabalho tem como objetivo apresentar estudos investigativos correlatos a modelagem do principal elemento da geracao distribuida por fonte solar, o modulo fotovoltaico, por meio da utilizacao de programas computacionais no dominio do tempo. Serao avaliados dois modelos matematicos que representam o comportamento do modulo fotovoltaico na plataforma Matlab/Simulink, dos quais um deles e disponibilizado pela biblioteca deste software, fundamentado na modelagem tradicional, e o seguinte implementado de forma simplificada. Complementarmente ao estudo e analise computacional das distintas tecnicas de modelagens, tem-se a avaliacao de desempenho dos modelos por meio de ensaios reais em campo. Palavras-chave: Geracao Distribuida, Modelagem, Modulo Fotovoltaico, Redes Inteligentes. ABSTRACT This paper aims to present investigative studies related to modeling of the main component of solar distributed generation, the PV modules, by means of simulation software in the time domain. Two mathematical models will be evaluated that represent the behavior of the photovoltaic module in the Matlab/Simulink platform, one of them being available from the software library, based on traditional modeling, and the other one implemented by a simplified way. In addition to this study and computational analysis of different modeling techniques, the paper presents a real performance evaluation through practical results. Keywords: Distributed Generation, Modeling, Photovoltaic Module, Smart Grid.