MODERN APPROACH TO THE PROBLEM OF ELECTRICITY QUALITY

prof. Dr. Vladimir Katic

University of Novi Sad, Faculty of Technical Sciences,

LECTURE 23.6.2022. from 13:00 to 14:00

Brief content: In recent years, the interest in the field of electrical energy quality (KVEE) has been renewed among many researchers from the academic community, as well as experts from the economy. The main reasons are the constant complexity of the electric power system, the wide use of non-linear energy converters, the connection of renewable energy sources and distributed production, and the increase of electric vehicles and other means of electric transport with high requirements for fast energy transfer (charging), as well as the increasingly pronounced need for storage electric energy. On the other hand, the digitalization of the electric power system is increased by the application of advanced computer systems, devices based on microprocessor control systems, which are very sensitive to disturbances and distortions in the power supply. For this reason, this lecture will focus on the quality of delivered electricity. It includes voltage distortions and disturbances, such as harmonics, dips/hops, flicker, interruptions, etc. Each type of disturbance is characterized by a specific digital signature (characteristic), which should be adequately detected, classified, characterized and recognized as a possible threat (or not) to normal operation. Modern methods of treatment of these signals and corresponding protection systems are based on monitoring its effective value. However, digital signatures of KVEE disturbances can be analyzed by advanced digital signal processing methods, such as parametric, non-parametric and hybrid. Recently, compressive sensing methods were introduced for digital processing and signal transmission, while artificial intelligence methods are used for the classification, characterization and eventual localization of disturbances.

The aim of the lecture is to present an overview of different methods of analysis and their application in characterization. Special focus will be on harmonics, because they can be a source of possible resonance in the network, and advanced methods of detection and characterization of voltage drops, because they can have serious negative effects, accompanied by financial losses. Methods using harmonic imprinting and deep learning algorithms will be presented in more detail.

Keywords: Power quality, Digital signal processing, Harmonics, Voltage dips/spikes, Harmonic footprint.