Ana Roxana Ciupuliga

Round-the-Year Security Analysis With Large-Scale Wind Power Integration

The ongoing liberalization process together with the growing penetration of renewable energy sources (RES), e.g. wind power, require an internationally oriented transmission planning approach that considers the increased uncertainties in terms of trade, location of generation and output of intermittent generation. This paper identifies and ranks bottlenecks, which is the first step of the transmission planning process for interconnected high-voltage grids. A round-the-year approach is proposed by combining market simulations with static security analysis. Many combinations of load and generation (including RES) are created and analyzed, using unit dispatch based on cost optimization. For each combination, the branch loadings are determined for normal and contingency situations. A statistical risk-based approach for ranking the most severe bottlenecks is developed. The method is illustrated on a modified New England test system where wind power was added at several buses. The risk of overload versus amount of installed wind power is also assessed.

Fault ride-through requirements for onshore wind power plants in Europe: The needs of the power system

Wind power plants show different behavior than conventional (synchronous) generators. As the traditional power systems mainly consisted of centralized generation by synchronous machines feeding passive loads, it was well-understood how the system reacted in normal operation as well as during disturbances. As wind power plants are foreseen to increase in size and the amount of installed wind power will grow, the relative contribution of equipment not exhibiting this common behavior increases. At the same time power electronics offer opportunities for additional features to stabilize the power system. Transmission system operators impose requirements on the (dynamic) capabilities of connected new generation resources (including wind power plants) which are specified in grid codes. In this paper, the importance of such requirements is explained by looking at the needs of the power system and by showing simulation results for a test network. The paper facilitates a detailed understanding of the underlying phenomena related to grid code requirements with a focus on low-voltage ride-through and voltage support by reactive current boosting.

Round-the-year security analysis with bottleneck ranking for interconnected power systems with large-scale wind power

The ongoing liberalization process in Europe together with the growing penetration of renewable energy sources (RES), e.g. wind power, require an internationally oriented transmission planning approach that considers the increased uncertainties in terms of trade, location of generation and output of intermittent RES. This paper identifies and ranks bottlenecks, which is the first step of the transmission expansion planning process of interconnected transmission grids. A round-the-year approach is adopted by combining market simulations with static security analysis. Many combinations of load and generation (including renewables) are created and analyzed, using unit dispatch based on cost optimization. For each combination the branch loadings are determined for normal and contingency situations. A statistical risk-based approach for ranking the most severe bottlenecks is developed. The method is illustrated on a modified New England test system where wind power was added at several buses. A regional analysis and a detailed per-area analysis are presented.

A market-based investigation of large-scale Renewable Energy integration in Northwestern Europe

A high increase in the installed capacities of Renewable Energy Sources (RES) is expected by 2020 and beyond in Europe, and power systems planners and regulators have to make sure that the power systems are designed and operated to make optimal use of the potential of these clean energy sources. This paper investigates the consequences of integrating large-scale solar and wind power in the future Northwestern European power system. A zonal market model is used, where unit commitment and economic dispatch simulations for a given development scenario of load and generation, including wind power and solar power time series and inter-zonal transmission constraints, are with hourly resolution. The ability of the power system to absorb the available “green” energy is assessed. Moreover, factors that can hamper or improve the RES integration are identified by performing a sensitivity analysis on a subset of the scenario attributes.

The impacts of extra load from EVs in the Netherlands: A North-West Europe case study

The deployment of EVs leads to a shift of the demand from transport to the power sector. This paper shows that in order to perform a realistic evaluation of the EVs integration impacts on a power system, the future developments in the increase of interconnection capacities should be taken into account. For this, three different charging scenarios are developed and tested using a North-Western Europe system model, together with a unit commitment and economic dispatch tool. EVs load time series are generated for each scenario by a stochastic model which is based on real commuting patterns of the Dutch population. The results indicate that EVs load is mainly supplied by conventional generation: gas, coal and nuclear. It is also noted that EVs lead to a very low increase in wind power utilization and even to a substitution of hydro generation.

Approval procedures and consensus for building transmission lines: Obstacles and solutions

This paper proposes a new approach — set up within the REALISEGRID research project — for speeding up approval procedures for building transmission infrastructure. The experiences of Transmission System Operators from Netherlands, Italy, France, Austria and Germany are studied in order to generalize and pinpoint the main weaknesses and strengths of current approval procedures. Recommendations concerning how to reduce the time needed for approval procedures are made. The problem of consensus improvement is also analysed. Suggestions for better structuring of the decision process in transmission planning, with high involvement of stakeholders, are made. A systemic approach for speeding up authorization procedures is proposed by combining the country survey and the consensus improvement findings. Actions are defined on different time horizons.

Round-the-year security analysis with large-scale wind power integration

The ongoing liberalization process together with the growing penetration of renewable energy sources (RES), e.g., wind power, require an internationally oriented transmission planning approach that considers the increased uncertainties in terms of trade, location of generation, and output of intermittent generation. This paper identifies and ranks bottlenecks, which is the first step of the transmission planning process for interconnected high-voltage grids. A round-the-year approach is proposed by combining market simulations with static security analysis. Many combinations of load and generation (including RES) are created and analyzed, using unit dispatch based on cost optimization. For each combination, the branch loadings are determined for normal and contingency situations. A statistical risk-based approach for ranking the most severe bottlenecks is developed. The method is illustrated on a modified New England test system where wind power was added at several buses. The risk of overload versus amount of installed wind power is also assessed.