Laboratory of Electric Power Supply

Real Time Digital Simulator (RTDS): orodje za preizkušanje vodenja in zaščite EES
Real Time Digital Simulator (RTDS)

Research activities of the Laboratory of electric power supply are focused on a several fields. The first area of research represents the so called FACTS technology (Flexible AC Transmission System) which is based on power electronics devices and can be considered as a technology for future power system development.

In the broad area of research, most attention is devoted to the question: “What can be achieved in electric power system by including FACTS devices?” Within this framework static and dynamic power system phenomena are studied (power flow redirection, impact of FACTS on transient stability improvement, power oscillation damping, etc.). A theoretical breakthrough was achieved in the field of electric power system energy functions. New energy functions have been found for the power system with FACTS devices included. Several studies have been also made in the collaboration with Slovenian transmission system operator ELES regarding newly installed phase shifting transformer, which has a very strong influence in controlling the power flow through Slovenian power system.

Next research field covers the problems of electric power supply of industrial plants. Static and dynamic phenomena in distribution RTDS-3networks are simulated in order to enable proper planning of industrial power systems (fault calculation, voltage profile, losses, motor starting, dynamic behavior at supply reconnection, etc.). Co-ordination of overcurrent (phase to phase and earth fault) protection devices also plays an essential role in industrial network power supply. The goal of computer aided overcurrent protection co-ordination is to assure highest power supply reliability of distribution and industrial users.

Newest research activities are oriented towards the alternative power network possibilities which could connect various dispersed alternative energy sources (photovoltaic, fuel cells, wind energy sources, micro hydro power plants) and possibilities for inclusion of wind power plants into Slovenian power system. Among others, we have developed a detailed model of a doubly fed induction machine, used in the first Slovenian pumped storage hydro power plant Avče.

Our laboratory is also the owner of a Real Time Digital Simulator (RTDS), which is a very powerful tool for conducting operational tests on various protection and control power system elements. RTDS enables the closed-loop testing of actual equipment, used in the real power system, whereas the rest of a power system is digitally modeled within the simulator. This equipment is used for both the research and also commercial projects.

Our laboratory has been involved in numerous Slovenian projects. In addition, in the international environment our work in the field of protection coordination in industrial power networks is in progress in cooperation with Siemens AG, Erlangen, Germany.