Lightning stresses in HVDC Inga – Kolwezi stations
Client: Fichtner GmbH & Co. KG
A refurbishment of a high voltage direct current (HVDC) connection Inga – Kolwezi was coming to a finish in 2012. The connection transmits power from Inga Falls on the Congo River to the copper mining district of Katanga in the Democratic Republic of Congo. Company, performing refurbishment, suggested installing additional surge arresters in order to protect the station equipment from potential over-voltages in cases of direct DC line lightning strikes. Our task was to find the source of oscillations that was said to cause violation of acceptable over-voltages on thyristor valves.
Thermal power plant Šoštanj transient and small-signal stability analysis for different topologies of connecting unit TEŠ 6
Client: ELES, d.o.o.
In 2012, details on selected topology for connecting unit TEŠ 6, were not yet approved. This is why transient stability of several possible topologies had to be analysed, considering three-phase short circuits both on unit’s terminals as well as in substation Podlog. Besides, small-signal stability was also investigated in case of a negative impact on oscillation modes damping.
Identification of synchronous generator parameters
Client: Siemens AG, Erlangen, Germany
Siemens is developing a software that would be capable to estimate synchronous machine parameters by having access to PMU measurements during transients. In this way it is said to be possible to obtain enough information about the machine itself without even entering the power-plant object. Such information is a necessity for conducting competent computer simulation analysis. The goal of the project was to investigate the possibility for using linear Heffron-Phillips model of the machine for this purpose.
Up to 1000 MW HVDC connection between Slovenia and Italy: technical and economic feasibility of 1000 MW HVDC connection between Slovenia and Italy
Client: ELES, d.o.o.
Note: in cooperation with EIMV
The consideration of building a second unit of nuclear power plant Krško brought up ideas of possible high voltage direct current (HVDC) connection between Slovenia and Italy in the range up to 100 MW. The main goal of the research was to make an overview of both technical as well as economic aspects of building such connection. A comparison between classical (thyristor) and newest (VSC) HVDC technology was presented. In addition, possibilities for improving oscillation damping by a special HVDC control-mode was analysed by performing small-signal stability analysis.
Short-circuit limitation possibilities in Slovenian power system
Client: ELES, d.o.o.
Note: in cooperation with EIMV