Penetration Level Of Wind Energy Research Articles

Smart Management of HVDC Interface Flow for Jeju Island System with High Penetration of Wind Energy

The recent concerns over the threat of global climate change and the requirements of national reduction of CO2 emission have led to the diversification of energy resources and a large scale integration of renewable resources. For island systems, however, the penetration level of renewable energy should be limited to maintain the power system security perspectives to frequency and voltage stability. The main interest of this paper is the operation of Jeju island system with a high penetration level of wind energy. As an option to make a breakthrough against the technical constraints, this paper presents a smart algorithm to set the active power of HVDC (High Voltage Direct Current) interties, which are to supply the power deficit and to regulate the frequency of the system.

Forecasting the Wind to Reach Significant Penetration Levels of Wind Energy

Advances in atmospheric science are critical to increased deployment of variable renewable energy (VRE) sources. For VRE sources, such as wind and solar, to reach high penetration levels in the nation's electric grid, electric system operators and VRE operators need better atmospheric observations, models, and forecasts. Improved meteorological observations through a deep layer of the atmosphere are needed for assimilation into numerical weather prediction (NWP) models. The need for improved operational NWP forecasts that can be used as inputs to power prediction models in the 0–36-h time frame is particularly urgent and more accurate predictions of rapid changes in VRE generation (ramp events) in the very short range (0–6 h) are crucial. We describe several recent studies that investigate the feasibility of generating 20% or more of the nation's electricity from weather-dependent VRE. Next, we describe key advances in atmospheric science needed for effective development of wind energy and approaches to achieving these improvements. The financial benefit to the nation of improved wind forecasts is potentially in the billions of dollars per year. Obtaining the necessary meteorological and climatological observations and predictions is a major undertaking, requiring collaboration from the government, private, and academic sectors. We describe a field project that will begin in 2011 to improve short-term wind forecasts, which demonstrates such a collaboration, and which falls under a recent memorandum of understanding between the Office of Energy Efficiency and Renewable Energy at the Department of Energy and the Department of Commerce/National Oceanic and Atmospheric Administration.

Added Value of Power Control in Improving the Integration of Wind Turbines in Weak Grid Conditions

For economical reasons, wind turbine systems must be located in favourable sites generating a higher pro- ductivity. These are often located in areas with weak electric grid infrastructures. The constraints related to this type of grids limit the penetration levels of wind energy. These constraints are mainly related to power quality in the grid as well as the economical aspects of the project. In this study, we take into account the slow voltage variations and the flicker phenomenon. The models used are based on the development of a set of relations derived from engineering knowledge related to both technical and economical points of view. The maximal penetration level of a fixed speed wind turbine system is determined for a given grid. The power control has been investigated to improve wind turbine system integration. Obtained results show the necessity to adapt technological choices to the requirements of weaker grids. Penetration levels and wind turbine cost may be greatly improved using variable speed systems.

Quantifying the impacts of wind variability

Although the issues surrounding the introduction of wind energy into electricity networks tend to be controversial, an increasing number of analytical studies suggest that the issues can be addressed at modest cost. This paper first discusses the key characteristics of electricity networks in order to establish the technical framework within which wind operates. Drawing on actual data from western Denmark, it is shown that the additional fluctuations encountered by system operators are measurable – and manageable. The importance of aggregation is emphasised and recent data from the British system operator are used as a basis for an estimate of additional balancing costs with wind energy penetration levels up to 40%. Above a penetration level of about 5%, additional costs are incurred as the ‘capacity credit’ of wind falls, which reduces the load factor of thermal plant. Combining this ‘backup’ cost with the costs of extra balancing, it is suggested that the extra cost to the consumer of wind variability at the 40% level is likely to be around £6/MWh – about 5% of the typical domestic electricity price. Factors that may reduce this extra cost, such as demand-side management and better wind forecasting, are also discussed.

The effect of spatial dispersion of wind power plants on the curtailment of wind power in the Greek power supply system

AbstractTo meet the national target of 29% for electricity production from renewable energy sources by 2020 in Greece, effective implementation of massive wind power installed capacity into the power supply system is required. In such a situation, the effective absorption of wind energy production is an important issue in a relatively small and weak power system such as that of Greece, which has limited existing interconnections with neighboring countries. The curtailment of wind power is sometimes necessary in autonomous systems with large wind energy penetration. The absorption or curtailment of wind power is strongly affected by the spatial dispersion of wind power installations. In the present paper, a methodology for estimating this effect is presented and applied for the power supply system of Greece. The method is based on probability theory, and makes use of wind forecasting models to represent the wind energy potential over any candidate area for future wind farm installations in the country. Moreover, technical constraints imposed by the power supply system management, the commitment of power plants and the load dispatch strategies are taken into account to maximize the wind energy penetration levels while ensuring reliable operation of the system. Representative wind power development scenarios are studied and evaluated. Results show that the spatial dispersion of wind power plants contributes beneficially to the wind energy penetration levels that can be accepted by the power system. Copyright © 2009 John Wiley & Sons, Ltd.

Control Algorithm for Coordinated Reactive Power Compensation in a Wind Park

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The penetration level of wind energy is continuously growing, and it is especially relevant in European countries such as Denmark, Germany, and Spain. For this reason, grid codes in different countries have been recently revised, or are now under revision in order to integrate this energy in the network taking into account the security of supply. This paper is related to reactive compensation, which is one aspect usually included in these codes. On the other hand, a great number of installed wind parks are formed by fixed speed wind turbines equipped with induction generators. The typical scheme for reactive compensation in this kind of wind parks is based on capacitor banks locally controlled in each machine. This configuration makes very difficult to follow the requirements of the new grid codes. To overcome this problem, a configuration with a central controller that coordinates the actuation over all the capacitor steps in the wind park is proposed in this paper. A central controller algorithm that is based on a dynamic programming is presented and evaluated by means of simulation. At this time, the proposed scheme has been installed at the Sotavento Experimental Wind Park (Spain) and it is currently being tested. </para>

Wind turbines: New challenges and advanced control solutions

Wind turbines: New challenges and advanced control solutions

Wind Integration Cost Impact Study for the Arizona Public Service Company: Modeling Approach and Results

The objectives of this study were to analyze operating impacts and costs of integrating wind energy in the Arizona Public Service (APS) balancing area, due to the variability and uncertainty of wind energy. Wind energy penetration levels from 1% to 10% were considered, corresponding to wind power levels of 100 MW to 1400 MW. A production cost simulation was conducted using APS system modeling software to assess the costs, by comparing the total production cost of the system with wind energy with a reference case that excludes the variability and uncertainty of wind energy. For APS's system, with an anticipated peak load of 7,905 MW in 2010, the integration costs were $0.91, $3.25, $3.57, and $4.08 per MWh for 1%, 4%, 7% and 10% wind energy. The geographic diversity of locating wind power plants over a large area was considered and found to have an important influence on the total integration cost.

A linear approach to study the influence of asynchronous wind parks on isolated networks

This paper deals with the study of power quality in an isolated system with high wind energy penetration level. An induction wind plant, a synchronous power plant and a network constitute the analysed system. The work focuses on studying the effect of mechanical power from wind on load voltage and network frequency fluctuations. A linear model for the complete system is proposed in order to use eigenfrequencies and Bode plots to carry out this study.

Wind farms connected to weak grids in India

AbstractThis article describes the mutual influence between the wind turbines and the power quality in the Indian power systems. The Indian power systems are weak in general and the wind energy development has been very fast and concentrated in a few rural areas where the existing transmission and distribution grids are very weak. Therefore the mutual influence between wind turbines and power quality is particularly strong in India. The wind farms influence power quality aspects such as steady state voltage, power factor, flicker and harmonic and interharmonic distortion. The power quality of the grid influences the power performance and safety of the wind turbines and the lifetime of mechanical and electrical components. The findings presented are general for wind farms connected to weak grids, but the Indian case is pronounced concerning weakness of grid as well as wind energy penetration level. Copyright © 2001 John Wiley &amp; Sons, Ltd.

Reliability/Cost Implications of Utilizing Wind Energy in Small Isolated Power Systems

The rapid growth of wind energy applications in electric power systems dictates a need to develop comprehensive techniques that can be used to evaluate the economics involved and the reliability of power supply that can be achieved from the utilization of wind energy sources. These sources have the potential to significantly reduce operating costs in small isolated systems which are generally supplied using costly diesel fuel. This paper presents a simulation method that provides objective indicators to help system planners decide on appropriate installation sites, operating policies, selection of wind or diesel units in capacity expansion and optimum wind energy penetration levels when utilizing wind energy in small isolated power systems.

A general simulation algorithm for the accurate assessment of isolated diesel-wind turbines systems interaction. Part II: Implementation of the algorithm and case-studies with induction generators

In the second part of this two-part paper, a general algorithm to simulate and assess the dynamic behavior of any isolated diesel-wind turbine power system is analyzed and implemented. It is presented how the various power system and wind energy conversion system (WECS) component models described in detail in Part I of the paper can be implemented in order to create integrated simulation software. Case studies for the small size isolated power system on the French island of Desirade are given and analyzed. The algorithm is validated and its usefulness to determine the wind energy penetration level at any disturbed operation conditions is demonstrated. >

A SIMULATION MODEL FOR THE RELIABLE INTEGRATION OF A 4·5 MW WIND FARM INTO THE POWER GRID OF THE CRETE ISLAND

Abstract This paper describes a computer simulation model which has been developed to study the effects of integrating wind energy conversion systems (WECS) into autonomous power systems. The quality of the interconnected system performance is specified in terms of operational constraints. Load-flow and power-system-stability studies were preformed in order to evaluate the penetration impact of a 4·5 MW wind farm on the local grid fo Sitia-Crete. The results show that the above wind energy penetration level will not cause any problem to the existing electric power grid.

Wind Oscillatory and Gusting Torque Effect on a Power System

The dynamics of a wind turbine driven induction machine and the power system to which it is connected in a dispersed mode are described. The sources of disturbances are identified as ramp and low frequency cyclic turbine torque variations as a consequence of sharp fronted wind gusts and tower shadow, rotor unbalance, etc. Studies have been performed for two levels of wind energy penetration in a single area power system and in a multiarea interconnected power system. Results show that substantial wind energy penetration levels can be handled in a multiarea power system.