Análises de componentes supraharmônicos baseadas na norma CISPR 16: comparação dos métodos de medições e implementação de interface gráfica

Abstract

In the last decade, waveform distortions between 2 kHz and 150 kHz gained more notoriety and several laboratories and research centers began to carry out studies on the subject. The term supraharmonic (SH), given to this frequency range, is relatively recent and was first mentioned by A. McAechern at the IEEE-PES GM 2013 in Vancouver. SH emissions were intensified mainly by the expansion of alternative energy sources connected to the electric power system, whose connection is necessarily carried out by static energy converters, which are one of the main causes of SH emissions. Given this and the relevance that the topic has gained in the last decade, the present work aimed to study of the supraharmonic distortions and also the existing measurement methods guided by the CISPR 16 standard. This standard proposes two measurement methods, which were called in this work conventional heterodyne and the method based on Short-Time Fourier Transform (STFT). In addition to these, an alternative method called here modified heterodyne was implemented, in which the use of fast Fourier transform makes signal processing more advantageous in terms of measurement time than for the conventional heterodyne method. To validate the existing methods and perform the necessary analyses, real signals were used, available in the PANDA (equiPment hArmoNic Database database), which commonly have high frequency distortion content, such as photovoltaic systems, electric vehicle charging and of LED lamps. Furthermore, synthetic signals were used whose natures were varied in AM modulation signals, FM modulation signals and signals without modulation with different types of previously known SH components. All simulations were performed in MATLAB software, in which a graphical interface was also implemented to facilitate the analysis by an end user. In this interface, the measurement method based on STFT was implemented and several analyzes and graphs can be visualized in it. As a result, a robust database and quasi-peak curves were presented for each type of signal in the three methods used. Through these, it was possible to verify and compare the three study methods, attesting to the feasibility of the method proposed in this work, called adapted heterodyne. In addition, results were also presented for the graphical interface with variation of synthetic and real signals.