Intelligent electronic device based methods for observability and response of smart gridsSODIN, DENIS (Avtor) Rudež, Urban (Mentor) intelligent electronic devicephasor measurement unitsmart meterIEEE C37.118 standardpower system measurementselectric power systemsmart gridfrequency stabilityunder-frequency load sheddingshort-circuit faultsfault localizationfault classificationFor some time now, we have been observing clear trends of climate change all over the world that are disturbing the delicate balance of the ecosystem to a not inconsiderable degree. While some tend to attribute these phenomena to processes on the scale of a geological era, i.e., to enormous cyclical climate fluctuations over millions of years, others claim that the industrial and agricultural activities of recent decades have had influence on this process by releasing an unprecedented amount of greenhouse gases into the atmosphere. This is primarily a consequence of the widespread use of fossil resources as a source of energy, particularly for electricity generation. The limited availability of fossil resources and their impact on the ecosystem are among the most important factors that require an economy based on the use of renewable and clean energy, which can provide a sufficient guarantee of sustainability in the long term. To achieve this, the current electric power system is undergoing significant changes, mainly through the massive integration of renewable sources. Conventional power generation plants (especially thermal) are being decommissioned and replaced by decentralised, sustainable and renewable energy sources, especially wind and solar power plants. While this energy transition brings significant environmental benefits, it also leads to increased complexity of the power system, resulting in unprecedented power system behaviour and new operational challenges. More than ever, electricity is an integral part of our daily lives, so prolonged power outages have significant negative social and economic consequences. In this context, this thesis addresses the real-time observability of the electric power system and the preventive and response measures used to mitigate the consequences of power outages for consumers. In the first part, the emerging smart grids and their challenges are briefly presented and their characteristics compared to the conventional power system are outlined. Then, the legacy SCADA monitoring system and the current state-of-the-art synchronised monitoring technology, enabled by phasor measurement units, are introduced. Here, the theoretical background and main advantages of phasor technology are explained, as well as considerations for its proper use in real applications. Next, the basis of one of the applied preventive protection measures related to the frequency stability of the power system, i.e. under-frequency load shedding, is explained in more detail and a novel scheme for its triggering is proposed. In addition, the effectiveness of the scheme is verified through hardware-in-the-loop testing and further developed for applicability in the real-environment. The next chapter shows the importance of power system protection and explains the need for quick fault localization. An extension of the fault localization algorithm is proposed that increases the precision of fault localization and is able to classify the fault type and determine the fault impedances while also requiring fewer measurement units to do so. Furthermore, this chapter presents a framework required for the successful implementation of the proposed algorithm in a real environment. At the same time, the framework reduces the amount of data transmitted over the wireless communication network, thereby lowering the operating costs of the distribution system operators. Finally, the conclusions summarise the main results of the thesis.20232023-09-20 12:55:00Doktorsko delo/naloga150568sl