ISSN 1805-3386

April 10, 2020


2018 No.3

Impact of the Ground on the Series Impedance of Overhead Power Lines

Margitová, A., Kolcun, M., Kanálik, M.

An overhead power line is a structure used in the electric power system to transmit electrical energy. The performance of overhead power lines depends on their parameters. There are four basic electrical parameters of power lines: resistance, inductance, capacitance, and shut conductance. The paper focuses on the calculation of the series impedance of overhead lines (resistance and inductance) by three different methods (Carsonʹs method, Rüdenbergʹs method and the theory of complex penetration depth) considering the impact of the ground return path. There is also the comparison of these methods and their application on models of real power lines of different voltage levels provided in this paper.


Keywords: electrical parameters of power lines, resistance, inductance, series impedance, Carsonʹs method, ground return, complex penetration depth.


Full paper (.pdf) - Download here


Design of Pseudoinverse Method for Robotic Arm

Hock, O., Sedo, J.

Pseudoinverse method for control end-effector movement of a robotic arm is presented in this paper. For that task we used the robotic arm DOBOT. We made simulation model in Matlab environment and SimMechanics toolbox. We described the pseudoinverse method and problem-solving of pseudoinverse for non-square matrices. In the near future we will make implementation of this method to the control end-effector movement of a robotic arm and therefore we created a simulation to how many digits we will need for correct calculating of goniometric functions in DSP.


Keywords: inverse kinematics, Matlab Simulink simulation, robotic arm, pseudoinverse method, SimMechanics.


Full paper (.pdf) - Download here


Modelica in Area of Thermodynamic and Energy Systems Applications with a Focus on ClaRa Library

Vojáèek, A., Ježek, F.

The focus of this investigation is the development of an advanced transient model to describe the operation of a coal fired power plant which supplies electric power for a pyrometallurgy unit. Particular attention was paid to the effects of so called „downswings“ (cut-off the electric arc). The performance of the unit during such failures (accumulation of energy in steam boiler during fast transient of turbine power output) was investigated using a dynamic model. The modelling of the power plant was performed on the object-oriented, multi-domain modelling language Modelica and free ClaRa library.


Keywords: transient, system modelling, Modelica, thermal hydraulics, downswings.


Full paper (.pdf) - Download here


Testing of Dynamic Models for Stability Studies

Máslo, K., Hába, T.

This paper deals with turbine-governor and excitation system dynamic models which are suitable for dynamic stability assessment of a transmission system. ENTSO-E uses the Common Grid Model Exchange Specification (CGMES) to facilitate the exchange of operational and grid planning data among transmission system operators. CGMES also includes a detailed description of the models needed to perform dynamic stability studies. These models are compared with the models implemented in the network simulator MODES.


Keywords: dynamic stability, excitation and turbinegovernor models, power system stabilizer.


Full paper (.pdf) - Download here