Historical wind deployment and implications for energy system models

This study presents a technoeconomic analysis of a hybrid wind‐PV (photovoltaic) power plant (HPP) compared to onshore wind power plants (WPPs) and photovoltaic power plants (PVPPs) in the Nordic electricity market, focusing on locations in Finland and Sweden. Wind power capacity has recently increased significantly in the Nordics, increasing the profit cannibalization of wind power. Renewable energy subsidies have been phased out in Finland and Sweden, thus new wind and PV power value creation is formed from the power market. The PV power capacity has also encountered significant growth in the Nordics. However, the capacity is still relatively low, allowing more revenue for produced PV power compared to wind power. The lower PV power profit cannibalization has increased interest in HPPs instead of WPPs. This contribution studies the economic feasibility of wind and PV power in changing market conditions in the Nordic electricity market. The market operation is modeled with three different configurations including selling all the power into the day ahead spot market and baseload or pay‐as‐produced power purchase agreement (PPA). In addition, a battery energy storage system (BESS) investment is analyzed using the operating strategy of shifting production to more profitable spot price hours. This study shows that due to the profit cannibalization and high cost of capital, the power plants are currently not profitable in the Nordic electricity market except when the bidding area has high average spot prices. The worst profitability was with WPPs when exposed to the market shape risk and with PVPPs when pay‐as‐produced PPA was agreed upon due to the higher levelized cost of electricity. However, the PV power profit cannibalization is expected to increase in the future as more PVPPs operate in the Nordic power market. Thus, the PVPP shape risk may increase in the future as well.

The penetration level of wind power into the power system over the world have been increasing very fast in the last few years and is still keeping the fast growth rate. It is just a matter of time that the wind power will be comparable to the conventional power generation. Therefore, many transmission system operators (TSOs) over the world have come up the grid codes to request the wind power plants (WPPs) to have more or less the same operating capability as the conventional power plants. The grid codes requirements from other TSOs are under development. This paper covers the steady state operation and low voltage ride through (LVRT) for the WPPs. The discussion of coping with the grid codes requirements is presented to come up with the grid codes complied WPPs solutions.

This paper briefly introduces a study of the determination of possible wind power potential in Kahramanmaras, For this purpose, a wind observation mast and its measurement equipment was established at the main campus of kahramanmaras Sutcu Imam University. Wind meteorological data were collected and recorded between the dates of October 05, 2010 and April 24, 2012. The recorded data were analyzed and processed using the WAsP program. The results of these analyses are used to estimate the wind power potential in the region and select the best fitted wind turbines to the site characteristics. Suitable sites were selected according to the created wind power and energy maps.

A review of the latest publications and updates of international grid codes shows that the future trend regarding frequency stability support by wind turbines (WTs) during disturbances will be to impose stringent requirements. Nevertheless, system dynamic response depends in a complex manner on wind power network development and power system characteristics and therefore, no general conclusions for all power systems can be made. This paper presents a comprehensive analysis of main effects of modern WTs able to support frequency stability on the dynamic performance of slow-response isolated thermal power systems. A general roadmap including key factors to consider for the determination of proper grid requirements for WTs is presented. The study is carried out for different wind power penetration levels and strategies for frequency support by WTs. The investigation is applied on the isolated power system in Northern Chile characterized by a thermal generation matrix with slow response generation units. Simulation results indicate that the adoption of severe grid requirements regarding frequency stability support by WTs is already justified for penetration levels above 5%, in which case the system performance even improves compared to the scenario without wind power.

Key challenges and prospects for large wind turbines

Power flow calculation is a basic tool for power systems operation and control. Considering static frequency regulation characteristics of power systems, dynamic power flow (DPF) gives more precise results of system operation with frequency deviation than conventional power flow. The increasing penetration of wind energy into power grid makes it necessary to take wind power into consideration in DPF calculation. The operational traits and frequency regulation characteristics of major types of wind turbines are discussed, including fixed speed wind turbines and variable speed wind turbines with integrated control strategy combining over-speed control and droop control. With the primary frequency regulation characteristics of wind turbines, a simplified DPF algorithm is proposed in this study for power systems integrating wind power generation. The IEEE 30-bus system is modified to verify the proposed method considering different levels of wind power penetration.

Multi-objective optimization of a hybrid system based on combined heat and compressed air energy storage and electrical boiler for wind power penetration and heat-power decoupling purposes

An extensive evaluation of wind resource using new methods and strategies for development and utilizing wind power in Mah-shahr station in Iran

Globally, wind power development is experiencing dramatic growth and wind power penetration levels are increasing. Wind generation is highly variable in time and space and it doesn't guarantee the system reliability and secure system operation. As wind power capacity becomes a significant portion of total generation capacity, the reliability assessment for wind power are therefore needed. At present, this operational reliability assessment is focusing on a generation adequacy perspective and does not consider transmission reliability issues. In this paper, we propose the critical transmission operating constraint prediction(CTOCP) system with high wind power penetration to enhance transmission reliability.

Recently, frequency regulation strategies have been widely adopted in the operation and control of doubly fed induction generator-based wind turbines (DFIG-WTs). Thus, wind power, which is becoming an increasingly important energy source, is expected to play a significant role in both power generation and frequency regulation in modern power systems. Under such circumstances, maintaining the reliability and frequency of power systems at a designated level may be more challenging due to inherent uncertainties in wind power generation. In this paper, the integrated assessment of the reliability and frequency deviation risks of power systems with a high penetration level of wind power is investigated. A multi-time scale analytical framework is proposed to calculate the integrated reliability and frequency deviation indices. The coupling between the reliability and frequency deviation is further addressed by developing a novel frequency-sensitive reliability model of the electric generator. Frequency deviations under supply/demand fluctuations and device failures are analyzed, and the power system frequency regulation process is modeled with the fuzzy adaptive virtual inertial response of DFIG-WTs and energy storage system (ESS). Furthermore, IEEE-RTS79 is used to verify the validity of the proposed model and solution method.

Wind energy is consistently attracting great research effort and actively developed in many countries. As a result, the penetration level of wind power in the power grid is increasing as well as the size of wind farms. A large-scale wind farm may consist of hundreds of wind turbines and its total installed capacity could be at a level of 1000MW or even more. Consequently, the large-scale wind farm could seriously impact the operation and control of the grid. To represent a large-scale wind farm, aggregated modelling takes advantage of fast computation and simplified implementation compared to detailed modelling that models every wind turbines individually and the interconnections among them. In this paper, three aggregated modelling techniques, namely, multi-machine equivalent aggregation, full aggregation and semi-aggregation are presented for power system transient stability studies based on a wind farm with permanent magnet synchronous generator (PMSG) wind turbines. Simulation results of the aggregated models and the detailed model are compared and analyzed respectively to prove the effectiveness of the aggregating techniques.

Large wind-turbine projects in the United States wind energy program

According to the characteristics of double fed asynchronous generator rotor energy flow, research and design based on the DSP control with two-way flow of energy function of Dual PWM converter and discusses the grid side converter control method of Dual PWM converter in particular. The wind turbine simulation model is established by using the electromagnetic transient PSCAD/EMTDC software. The simulation system is used to simulate the P, Q decoupling control and maximum wind energy tracking control of the generator. Wind is a natural phenomenon generated by the solar radiation heat, the earth's surface caused by uneven heating of the atmosphere. It is estimated that only 1% of the wind on the ground will be able to meet the needs of the world's energy. With the continuous improvement of the level of wind power generation technology, the cost of wind power gradually reduced, considering environmental benefits, the cost will be close to the cost of coal-fired power generation. Therefore, great efforts to develop wind energy as the representative of the renewable energy and new energy, to achieve sustainable development, has become the consensus of the whole society, strategic choice to solve the energy crisis and environmental problems. 2.Overview of control technology of doubly fed wind power gener ation Wind power is the kinetic energy contained in the natural wind into electrical energy in the process, the wind turbine wind energy capture and convert it into mechanical energy, driven by rotary generator, and the generator for converting mechanical energy conversion into electrical energy. As countries around the world pay more attention to wind power, wind power has become the world's fastest, most widely studied and applied new energy technology. With the development of wind power technology, wind turbine, wind turbine generator, converter and its control system and the way of the wind turbine, there are different types of. Among them, the doubly fed wind power generation system due to the converter control capacity is small, the speed of operation range wide characteristics become currently the world's most widely used VSCF wind power generation system. Variable speed constant frequency generator in asynchronous generator rotor side applied three-phase low frequency current to realize AC excitation, the output power is constant frequency and constant voltage amplitude, frequency, phase of the exciting current control. At the same time, the active power and reactive power decoupling control of the generator is realized by using the vector control technology. Control active power capable of adjusting the rotation speed of the wind turbine, to capture the maximum wind power tracking control; regulation of reactive power adjustable power factor and improve the dynamic and static stability of the wind turbine and power system operation. In addition, the VSCF wind power generation technology, so to achieve good flexible connection between the generator and power grid system, compared with the traditional constant speed constant frequency generation system easier to achieve grid connected operation and operation

According to measurements at meteorological stations, average annual wind speed on Sakhalin Island varies from 2 to 9 m / c. The average annual wind speed throughout Russia is in the same range. Therefore, the study of power characteristics of the wind on Sakhalin must give general wind energy properties throughout Russia. Processing of weather stations data has been carried out using the new approach. This methodology is based on the hypothesis that the wind speed at an arbitrary interval in time is a continuously differentiable function of time V ∞ (t) . It is assumed that the function V ∞ (t) is the result of such random process, when in regular intervals Т in the identical conditions this function keeps the continuity, differentiability, and has a large number of extrema, but quantitatively changes each time a little differently. Energy properties are characterized by an average wind speed and potential of wind energy. At the same time, unlike the meteorological tradition, potential of wind energy is defined as the energy of the air stream across a unit cross-sectional area at a given time interval Т . Such a definition of wind energy potential is necessary, because the performance of wind turbines in the time interval Т is determined by the value of the wind energy potential, defined for this time interval. A number of cyclic periods of time allows us to get a sample of random variables characterizing the properties of wind energy. For this sample on the base of methods of mathematical statistics the probability density function and the root mean square deviation of these random variables are determined. As a result of statistical processing of wind speed measurements at meteorological stations of Sakhalin, empirical probability density functions of random variables “average wind speed” and “annual wind energy potential” have been identified.

Evaluation of wind energy resource and wind turbine characteristics at two locations in China