GETINO, E., GARCÍA, E., DEŽELAK, K.
Analysis of the Spanish Electricity Market and Proposals for Future Development
KOMUNALNA ENERGETIKA / POWER ENGINERING, 33
Nowadays the electricity is found in any daily activity, while a state can not develop its economic and social potential without a consolidated electricity system. In sense of the liberalized electrical systems, the figure of an electric market becomes fundamental. This paper shows an overview of the Spanish electricity market, involving its problems and future objectives. Spain as a member of the European Union faces the demands proposed by the European Commission. The European challenge is not an individual challenge for individual member but requires the cooperation of all member states, moving towards an energetically integrated European Union.
SOMI, L., DEŽELAK, K., PIHLER, J.
ACCUMULATION SMALL HYDRO POWER PLANT ON THE EXISTENT LAKE
KOMUNALNA ENERGETIKA / POWER ENGINERING, 8
An article presents an Accumulation small hydro power plant on existent lake. The project could be built on an already existing infrastructure, consisting of an embankment, a tower and a lake outflow. In the paper the potential of the river Ledava in the western part of Goričko with the placement of the hydro power plant is dealt. The choice of technical equipment, location and the planned operation regime, as well as the construction and investment cost of the project are presented in the work.
BELE, A., DEŽELAK, K., ŠTUMBERGER, G.
MODELLING OF DOUBLE-CIRCUIT OVERHEAD LINE WITH TWO CONDUCTOR BUNDLE
KOMUNALNA ENERGETIKA / POWER ENGINERING, 13
Proposed paper deals with the development of the double-circuit overhead power line model with the two-conductor bundle – with so called "advanced model". The results obtained by proposed model are compared with the results given in the study titled "Mutual influences within the several circuits of overhead line" and results obtained by so-called "equivalent model". The equations for capacitance, inductance and resistance calculations are presented, as well. Finally, the advanced model was used for calculations of induced voltages in the case of overhead power line Beričevo–Krško.
DEŽELAK, K., JAKL, F., MARUŠA, R., PIHLER, J., ŠTUMBERGER, G.
IMPACT OF NON-ELASTIC EXTENSION OF CONDUCTORS ON THE OVERHEAD POWER LINE CONDUCTOR SAGS
KOMUNALNA ENERGETIKA / POWER ENGINERING, 14
Proposed paper deals with the problems regarding a non-elastic elongation of overhead conductors known as creep phenomena on account of mechanical yielding of material. Impact of non-elastic elongations of conductors is directly connected with the conductor sags and with smaller clearances between conductors and ground. Some results related to the researches in permanent elongations of conductors of the ACSR 490/65 type are presented, where compesation methods are applied as well.
BELIČ, E., DEŽELAK, K., ŠTUMBERGER, G.
A LINE VOLTAGE DEPENDENCY ANALYSIS ON ACTIVE AND REACTIVE POWER FLOW AT DIFFERENTC LOW VOLTAGE LINES
KOMUNALNA ENERGETIKA / POWER ENGINERING, 9
The paper provided presents a line voltage dependency analysis on active and reactive power flow. The line voltage dependency is studied based on analytical expression. For the analysis it is assumed that one end of the line is connected to infinite bus, while at the other end voltage is observed in dependency of active and reactive power flow. The analysis covers three different low voltage cables with two different lengths. The results shows that in low voltage network voltage significantly depends on active power flow, while reactive power flow dependency is minimal. Voltage dependency increases, when low voltage lines are extended.
DEŽELAK, K., KOTNIK, S., DEŽAN, K., BELIČ, E., IVANECKÝ, J., ŠTUMBERGER, G.
ACCEPTANCE INDICATORS OF A MICRO HYDRO POWER PLANT INVESTMENT FOR A MICRO HYDRO POWER PLANT "KOTNIK"
KOMUNALNA ENERGETIKA / POWER ENGINERING, 5
This paper deals with the impact of the energy cost, produced by a micro hydro power plant, on the acceptance indicators of a micro hydro power plant investment. The aforementioned acceptance indicators are the net present value and the internal rate of return. All calculations are performed for a micro hydro power plant "Kotnik" with power of 10 kW, where technical and essentially financial parts are observed.
DEŽELAK, K., JAKL, F., BELIČ, E., ŠTUMBERGER, G.
EMISSIONS OF ELECTRIC AND MAGNETIC FIELDS CAUSED BY 400 KV OVERHEAD POWER LINES TYPE DONAVA
KOMUNALNA ENERGETIKA / POWER ENGINERING, 8
In proposed paper the emissions of electric and magnetic fields caused by 400 kV overhead power lines type Donava are dealt. Firstly, the classical Donava type overhead power line is dealt, while different varity of conductor bundle are considered. Secondly, the Austrian type of overhead line is considered, firstly without and after with additional 110 kV system on the same tower.
BELIČ, E., SUKIČ, P., DEŽELAK, K., ŠTUMBERGER, G.
DYNAMICAL MODEL OF DISTRIBUTION NETWORK WITH DISTRIBUTED GENERATION
KOMUNALNA ENERGETIKA / POWER ENGINERING, 18
In this paper a dynamical model of distribution network with distributed generation is presented. Model of distribution network was developed using software package Matlab/Simulink with its blockset SymPowerSystems. Elements of utility network like supply network, power lines, load, and distribution transformer were modeled with elements which are already included in this blockset, but the distributed generator model was developed based on the current injection to the grid, considering references of active and reactive power. The aim of network modeling was to analyze the voltage profiles and transmission loses before and after connection of the distributed generation to the grid. Presented are the results of performed analysis.
IVANECKÝ, J., DEŽELAK, K., ŠTUMBERGER, G.
CONCEPT OF VIRTUAL POWER PLANT PARTICIPATION IN THE SLOVAKIAN ELECTRICITY MARKET
KOMUNALNA ENERGETIKA / POWER ENGINERING, 21
The proposed paper deals with a Virtual Power Plant (VPP) concept in the Slovakian electricity environment. The first part of paper explains the concept of VPP and also the reasons why is worth dealing with this concept. The second part of the paper briefly describes the market environment in the Slovakian power system, as well as methodology within individual constraints related to the operation of individual sources are considered.
DEŽELAK, K., DEŽAN, K., DEŽELAK, D., BELIČ, E., ŠTUMBERGER, G.
INTERNAL RATE OF RETURN FOR A SOLAR POWER PLANT IN CASE OF MOVABLE PHOTOVOLTAIC MODULS
KOMUNALNA ENERGETIKA / POWER ENGINERING, 8
In proposed paper the internal rate of return for a solar power plant investment is mainly dealt. The main parts of the solar power plant are represented by the photovoltaic moduls, which could be static or movable. In case of movable photovoltaic moduls, where moduls are following to the movement of the sun, the amount of the produced energy could be even up to 30 % higher than in case of static photovoltaic moduls. On the other hand an investment in movable solar plant leads to the higher initial costs of the whole investment.
DEŽELAK, K., PIHLER, J., FLUHER, B., ŠTUMBERGER, G.
COMPARISON OF SMALL HYDRO POWER PLANTS: HYDRO MATRIX TURBINE VS. MOVING HYDRO POWER PLANT
KOMUNALNA ENERGETIKA / POWER ENGINERING, 11
In proposed paper the comparison of two possible solutions for small hydro power plant construction is dealt. In that way the technical, as well as financial parts are observed. The first proposed solution is hydro power plant with the hydro matrix turbine, whilst the second solution is construction of so called moving hydro power plant. The choice of such solutions depends on particular water flow.
DEŽELAK, K.
ANALYSIS OF HYDRO POWER PLANT BY THE HILL-CHART DIAGRAM
KOMUNALNA ENERGETIKA / POWER ENGINERING, 3
In the paper the operational analysis of hydro power plant is represented. The turbine model, as one of the main part in hydro power plant, is obtained by the hill-chart diagram of the turbine. The whole model is built in program package Matlab/Simulink. The operational analysis of the hydro power plant is performed at the hill-chart basis regards on any flow and head, whilst the output parameters of model are turbine efficiency and power. The proposed model can be used as useful tool in the different operational regime estimation, even within the optimization algorithms.
DEŽELAK, K., OGOREVC, K., ŠTUMBERGER, G.
COMPARISON OF HYDROELECTRIC POWER PLANTS BOŠTANJ AND BLANCA
KOMUNALNA ENERGETIKA / POWER ENGINERING, 9
This paper presents a comparison between two hydroelectric power plants (HEPP), HEPP Boštanj and HEPP Blanca. This comparison consists of two parts. The first part is based on the comparison of their dam structures with the mechanical and electric equipment installed, while the second part contains an economic analysis performed with the RETScreen software. The results of proposed analysis show the financial pointers of both hydroelectric plants.
DEŽELAK, K., DEŽELAK, D., ŠTUMBERGER, G., JAKL, F.
CALCULATION OF THE TEMPERATURE OF THE OVERHEAD POWER LINE CONDUCTOR
KOMUNALNA ENERGETIKA / POWER ENGINERING, 16
Temperature of the overhead power line conductor during operation represents one of the basic limit parameter for overhead power line operating. The allowed conductor heating must be under the limit values, because of high impact to the mechanical parameters of the conductors and conductor sagging. In the paper, all of the results are obtained with the CIGRE method, while obtained results are shown in program package Matlab.
DEŽELAK, K., KADIŠ, J., ŠTUMBERGER, G.
CALCULATION OF AUDIBLE NOISE EMISSIONS CAUSED BY HIGH VOLTAGE OVERHEAD POWER LINES
KOMUNALNA ENERGETIKA / POWER ENGINERING, 16
The paper deals with the calculation of audible noise emissions caused by high voltage overhead power lines due to corona. The first part describes the theoretical basis of corona occurrence and its consequences. Furthermore, the paper presents frequently used methods for the calculation of audible noise emissions caused by high voltage overhead power lines. Electric field strength values around conductor are essential for audible noise emissions and the occurrence of corona, therefore, the comparison of three methods for the calculation of electric field was performed. All of the methods were used for calculating the audible noise emissions caused by various overhead power lines.