Session 23: Impact of RES and DG on Networks
The Influence of Wind Park Krš-Pađene on Reliability Indices of 110 kV Transmission Network
1Faculty of Electrical Engineering Osijek, Croatia; 2HEP Renewble energy Sources d.o.o. Zagreb, Croatia
This paper presents the reliability assessment of the southern part of Croatian transmission network and the influence of the wind farm on reliability indices. Croatian Electric Utility (HEP) Renewable Energy Sources with partner C.E.M.P. is developing wind farm in the region near town Knin. Wind farm will have installed capacity of 100 MW in the first phase. In the second phase additional 40 MW is planned to be installed. For the purpose of this paper, it was assumed that wind farm consist of the 50 turbine units, 2 MW each. Reliability assessment was performed, and reliability indices were computed for the case before and after construction of the wind farm. The reliability is analyzed using state enumeration method and NEPLAN software. Input data were obtained from annual reports of HEP TSO (Transmission System Operator) and statistic analysis of data was performed first. Since there are no statistical data for new cables and transformer stations that are constructed, input data for them were taken from the relevant literature. Probability of wind farm production level is taken from measured wind statistics. In reliability assessment Markov state space model of the wind generator, busbars, transformers, breakers and disconectors was used. Load is modeled at the output substation busbars with maximum active and reactive power. The simulations are performed in order to calculate reliability indices before and after the construction of wind farm. Conclusions and comments on the results are presented at the end of the paper.
Impact of Wind Power on Commercial and Physical Flows within the CWE Region
The paper aims at providing better understanding of the discrepancy between commercial and physical interconnection capacity for electricity. Loop flows, expected loop flows and the ways to deal with it constitute the focus of the discrepancy analysis. Apart from investigating the uncertainty aspect of loop flows, the variability and relative unpredictability of wind power are also analysed in the light of loop flows. The Central West Europe region is used as a practical case.
Probabilistic Load Flow Procedure for Assessing the Distributed Generation Impact on the High Voltage Network
University of Pavia, Italy
This paper presents a Probabilistic Load Flow (PLF) procedure that allows the impact of distributed generation (DG) on the transmission system to be assessed. By means of the Monte Carlo technique, several system states are simulated, varying the power injection of DG. The load flow solution is performed by the Newton-Raphson method and a distributed slack bus formulation is adopted, in order to distribute the active power mismatch (created by the random generation) on all the thermal units in the system. Tests are carried out both on a small system and on the Italian network. Results lead to conclude that the probabilistic approach to the power system analysis provides more indications than the traditional deterministic techniques, especially considering a high penetration of DG.
A Survey of the Spanish Framework for Production of Electricity from Renewable Sources
1University of Sevilla, Spain; 2Endesa, S.A
The reduction of pollutant emissions and greenhouse gases, as well as the strong energy dependence on fossil fuels (specialty fuel oil), among other reasons, have led in recent years many countries to develop policies to promote and encourage the use of other clean sources of energy. This paper presents an overview of the production of electricity from renewable sources in Spain. The paper reviews the current level of implementation of renewable energy and the forecast for the coming years. It also reviews the current support system (through premiums to production), the costs of introducing renewable energy into the electrical system and its beneficial effects on the electricity market. Finally, an analysis of the economic profitability of the main technologies for renewable electricity production used in Spain leads to the estimation of their respective minimum profitable feed-in tariff.
Review Paper on Wind Power Impact on Operation of Reserves
This paper reviews studies concerning new challenges for European transmission system operators (TSOs) when operating primary, secondary and tertiary reserves in a system with large amounts of wind power. The review adopts three perspectives. First, the impact on existing markets is discussed and it is shown that need for additional reserve requirements does not necessarily mean need for new reserve capacity. Secondly, possible designs of improved load-frequency control schemes are presented. The proposed solutions exhibit a trend towards market-based procurement mechanisms and automation of reserve operations. Finally, participation of wind power in load-frequency control is examined. Technical designs are presented for participation in primary control.