Large Wind Power Penetration Research Articles

Dynamic Voltage Stability of an Electric Power Network with Double Fed Induction Wind Power Generators

In recent years, the large penetration of wind power poses new challenges for the voltage stability analysis of an electric power network. In this paper is studied the effect of large scale integration of wind power in the dynamic voltage stability of a power network under a fault condition. The automatic voltage regulators of the generating units, the turbine speed governors and the double fed induction generator were modeled. Different load models were used and the under load tap changers were also taken into account. The simulation results were obtained using the EUROSTAG software package. Finally, some conclusions that provide a better understanding of the dynamic voltage stability in a system with a large amount of wind power generation are pointed out.

Deep learning model-transformer based wind power forecasting approach

The uncertainty and fluctuation are the major challenges casted by the large penetration of wind power (WP). As one of the most important solutions for tackling these issues, accurate forecasting is able to enhance the wind energy consumption and improve the penetration rate of WP. In this paper, we propose a deep learning model-transformer based wind power forecasting (WPF) model. The transformer is a neural network architecture based on the attention mechanism, which is clearly different from other deep learning models such as CNN or RNN. The basic unit of the transformer network consists of residual structure, self-attention mechanism and feedforward network. The overall multilayer encoder to decoder structure enables the network to complete modeling of sequential data. By comparing the forecasting results with other four deep learning models, such as LSTM, the accuracy and efficiency of transformer have been validated. Furthermore, the migration learning experiments show that transformer can also provide good migration performance.

A Selective Review on Recent Advancements in Long, Short and Ultra-Short-Term Wind Power Prediction

With large penetration of wind power into power grids, the accurate prediction of wind power generation is becoming extremely important. Planning, scheduling, maintenance, trading and smooth operations all depend on the accuracy of the prediction. However due to the highly non-stationary and chaotic behaviour of wind, accurate forecasting of wind power for different intervals of time becomes more challenging. Forecasting of wind power generation over different time spans is essential for different applications of wind energy. Recent development in this research field displays a wide spectrum of wind power prediction methods covering different prediction horizons. A detailed review of recent research achievements, performance, and information about possible future scope is presented in this article. This paper systematically reviews long term, short term and ultra short term wind power prediction methods. Each category of forecasting methods is further classified into four subclasses and a comparative analysis is presented. This study also provides discussions of recent development trends, performance analysis and future recommendations.

Steady State and Transient Analysis of FSIG and DFIG Integration to Grid for Different Penetration Levels using VSC-HVDC

Among all the Renewable Energy Sources Wind energy is the fastest growing energy source over the last decade mainly due to crucial developments of technology in wind energy. Nowadays, the penetration of wind energy is increasing in many countries in the world including India. The power system stability with large penetration of wind power is a concern for many electrical utilities. The common technical issues with increased penetration of wind energy are voltage and reactive power control, frequency control and Low Voltage Ride Through (LVRT) capability. The VSC-HVDC system with its benefit of independent control of active and reactive power promises to enhance the system stability at high penetration levels. The maximum wind penetration levels in to the grid is analysed for Fixed Speed Induction Generator (FSIG) & Doubly Fed Induction Generator (DFIG). The penetration levels are further enhanced by considering the evacuation of wind power with VSC-HVDC system without losing system stability. Different controllers for VSC-HVDC system are used to improve the stability and LVRT capability. Standard Benchmark System is considered, and the simulations are performed by using power system simulation software SIMPOW. Results shows that wind power evacuated through VSC-HVDC system has better stability and LVRT Capability compared to AC system at high wind penetration levels.

Robust Two-Stage Regional-District Scheduling of Multi-carrier Energy Systems With a Large Penetration of Wind Power

This paper proposes a robust day-ahead scheduling method for a multi-carrier energy system (MES), which would enhance the flexibility of power systems with a large sum of variable wind power. We build an MES model and propose an optimal MES schedule which helps MES reduce wind power curtailment in power systems. At first, electricity and natural gas networks are coordinated at the transmission (regional) level for accommodating the large penetration of wind power in regional MES. The distribution (district) level MES coordinates energy conversion and storage to jointly supply the electricity, natural gas, and heat loads. The transmission level MES is modeled using detailed network equations while the distribution level MES is modeled as a device with multiple input/output ports using the linear branch-flow-based energy hub model. A two-stage robust model is established to consider the variability of wind power at the two MES levels. The proposed problem is solved by a nested column-and-constraint (C&CG) generation method. The first-stage problem which schedules the hourly unit commitment is solved in the outer loop, while the inner loop solves the second-stage problem to realize the worst scenario. Several acceleration strategies are utilized to enhance the computational performance of the nested C&CG. Numerical results offered for a 6-bus 3-node system and a modified IEEE 118-bus 10-node system show the effectiveness of the proposed MES model and solution technique for enhancing the power system flexibility.

Integrated Disturbance Response Modeling of Wind-Integrated Power Systems to Quantify the Operational Reliability Benefits of Flywheel Energy Storage

Rapid growth of renewable power penetration has exposed modern power systems to high operating risks, due to intermittency and uncertainty inherent in such energy sources. It is therefore essential to assess the associated risks and explore potential resources to mitigate these risks. This paper presents a novel approach for response risk evaluation of wind-integrated power system. The proposed approach utilizes a probabilistic integrated disturbance model and introduces a new comparative risk index designated as the Response Risk Multiplication Factor to quantify the impact of increasing penetration of wind power and the contribution of flywheel energy storage system (FESS) on the power system operational reliability. The developed model incorporates the wind-power uncertainty, the specific charge/discharge, storage performance and failure characteristics of FESS and embeds the posterior probability approach to utilize the known information on time of day and FESS SOC. The developed model is applied to the IEEE Reliability Test System to illustrate its usability in assessment of the impact on power system operating risk due to large operating penetration of wind power and effectiveness of FESS in risk mitigation.

Battery Storage-Based Frequency Containment Reserves in Large Wind Penetrated Scenarios: A Practical Approach to Sizing

This paper focuses on the sizing of a battery energy storage system providing frequency containment reserves in a power system with a large wind power penetration level. A three-stage sizing methodology including the different aspect of battery energy storage system performance is proposed. The first stage includes time-domain simulations, investigating battery energy storage system dynamic response and its capability of providing frequency reserves. The second stage involves lifetime investigation. An economic assessment of the battery unit is carried out by performing the last stage. The main outcome of the proposed methodology is to choose the suitable battery energy storage system size for providing frequency containment reserve from augmented wind power plants while fulfilling relevant evaluation criteria imposed for each stage.

Technical and economic assessment of RES penetration by modelling China's existing energy system

The expansion of renewable energy sources for electricity generation is an important part of China's energy strategy to reduce the dominance of coal generated power. Different energy systems face unique challenges with their different energy structures and economic context, which make it necessary to identify the roadmap for renewable energy development with consideration of local energy system. Our study aims to fill a research gap by identifying the penetration of renewable energy in China's energy system. The study begins with a brief review of the current state of renewable energies in China and then identifies the effect of large penetration of wind power and solar energy. China's energy system is simulated using the EnergyPLAN model and assessed under different penetration points of renewable energy sources from technical and economic perspectives. Different realistic intervals of penetration are discussed. Finally, our analysis identifies that the maximum realistic penetration of wind power and solar energy are respectively 38% and 27%.

Novel Cost Model for Balancing Wind Power Forecasting Uncertainty

The intermittency of wind generation creates nonlinear uncertainties in wind power forecasting (WPF). Thus, additional operating costs can be incurred for balancing these forecasting deviations. Normally, large wind power penetration requires accurate quantification of the uncertainty-induced costs. This paper defines this type of costs as wind power uncertainty incremental cost (WPUIC) and wind power uncertainty dispatch cost (WPUDC), and it then formulates a general methodology for deriving them based on probabilistic forecasting of wind power. WPUIC quantifies the incremental cost induced from balancing the uncertainties of wind power generation. WPUDC is a balancing cost function with a quadratic form considering diverse external conditions. Besides, the risk probability (RP) of not meeting the scheduled obligation is also modelled. Above models are established based on a newly developed probabilistic forecasting model, varying variance relevance vector machine (VVRVM). Demonstration results show that the VVRVM and RP provide accurate representation of WPF uncertainties and corresponding risk, and thus they can better support and validate the modelling of WPUDC and WPUIC. The proposed cost models have the potential to easily extend traditional dispatches to a new low-carbon system with a high penetration of renewables.

Implications of environmental regulation and coal plant retirements in systems with large scale penetration of wind power

Over the last decade there have been a growing number of federal and state regulations aimed at controlling air emissions at power plants and/or increasing the penetration of renewable resources in the grid. Environmental Protection Agency regulations will likely lead to the retrofit, retirement, or replacement of coal-fired power plants while the state Renewable Portfolio Standards will continue to drive large-scale deployment of renewable energy sources, primarily wind. Combined, these changes in the generation fleet could have profound implications for the operations of the power system. In this paper, we aim to better understand the interaction between coal plant retirements and increased levels of wind power. We extensively analyze the operations of the PJM electricity system under a broad set of scenarios that include varying levels of wind penetration and coal plant retirements. Not surprisingly, we find that without transmission upgrades, retirement of coal-fired power plants will likely result in considerable transmission congestion and higher energy prices. Increased wind penetration, with high geographic diversity, could mitigate some of the negative effects of coal plant retirement and lead to a significant reduction in air emissions, but wind forecast error might impose operational constraints on the system at times of peak load.

Expansion of Transmission Networks Considering Large Wind Power Penetration and Demand Uncertainty

This paper presents an algorithm for solving the Transmission Expansion Planning (TEP) problem when large scale wind generation is considered. Variability of wind speed and demand uncertainty are also taken into account. The formulation includes the DC model of the network, and the obtained expansion plans minimize the investment, the load shedding, and also the wind generation curtailment. The Chu-Beasley Genetic Algorithm (CBGA) is used for finding feasible optimal expansion plans. Uncertainties are included by scenario reduction to obtain robust expansion plans capable of meeting the uncertainty set. The approach allows finding robust expansion plans to cope with the uncertainties in load forecasting and also to take advantage of wind generation. The proposed algorithm is validated on the 6-bus Garver system, IEEE 24-bus RTS test system and the real life South-Brazilian 46-bus system. Comparison with other methods is carried out to demonstrate the performance of the proposed approach.

Analysis of Grid Code Technical Requirements for Wind Farms Connected to the Grid in Penghu Island

Modern wind turbine technology has been a great improvement over the past couple decades, leading to large scale wind power penetration. The increasing penetration of wind power resulted in emphasizing the importance of reliable and secure operation of power systems, especially in a weak power system. In this paper, the main wind turbine control schemes, the wind penetration levels and wind farm dynamic behavior for grid code compliance were investigated in the Penghu wind power system, a weak isolated power system.

Wind power integration into the automatic generation control of power systems with large‐scale wind power

Transmission system operators have an increased interest in the active participation of wind power plants (WPP) in the power balance control of power systems with large wind power penetration. The emphasis in this study is on the integration of WPPs into the auto- matic generation control (AGC) of the power system. The present paper proposes a coordinated control strategy for the AGC between com- bined heat and power plants (CHPs) and WPPs to enhance the security and the reliability of a power system operation in the case of a large wind power penetration. The proposed strategy, described and exemplified for the future Danish power system, takes the hour-ahead regulating power plan for generation and power exchange with neighbouring power systems into account. The performance of the proposed strategy for coordinated secondary control is assessed and discussed by means of simulations for different possible future scenarios, when wind power production in the power system is high and conventional production from CHPs is at a minimum level. The investigation results of the pro- posed control strategy have shown that the WPPs can actively help the AGC, and reduce the real-time power imbalance in the power system, by down regulating their production when CHPs are unable to provide the required response.

Dynamic Performance Assessment of Wind Energy Pump Storage Units in Crete's Power System

Large scale integrating of wind power generation into a grid may raise serious stability issues. In this case energy storage systems seem to be suitable for balancing power and energy between the inconstant wind parks generation and the grid. In this paper, the impact of high wind power penetration on the dynamic performance and stability of power systems is investigated. More precisely, the focus of this study is to assess the operation of pump storage systems in the autonomous power system of a large island such as Crete. Results of this study show that it is possible to achieve a large wind power penetration without significant dynamic security problems, if wind energy pump storage units are in operation.

A decentralised multi-agent approach to enhance the stability of smart microgrids with renewable energy

This paper presents the impact of large penetration of wind power on the transient stability through a dynamic evaluation of the critical clearing times (CCTs) by using intelligent agent-based approach. A decentralised multi-agent-based framework is developed, where agents represent a number of physical device models to form a complex infrastructure for computation and communication. They enable the dynamic flow of information and energy for the interaction between the physical processes and their activities. These agents dynamically adapt online measurements and use the CCT information for relay coordination to improve the transient stability of power systems. Simulations are carried out on a smart microgrid system for faults at increasing wind power penetration levels and the improvement in transient stability using the proposed agent-based framework is demonstrated.

Modeling Large-Scale Wind Farms for Reliability Analysis Considering Wake Effect

Large scale wind power penetration has a significant impact on the reliability of the electric generation systems. A wind farm consists of a large number of wind turbine generators (WTGs). A major difficulty in modeling wind farms is that the WTG not have an independent capacity distribution due to the dependence of the individual turbine output on the same energy source, the wind. In this paper, a model of the wind farm output power considering multi-wake effects is established according to the probability distribution of the wind speed and the characteristic of the wind generator output power: based on the simple Jenson wake effect model, the wake effect with wind speed sheer model and the detail wake effect model with the detail shade areas of the upstream wind turbines are discussed respectively. Compared to the individual wake effect model, this model takes the wind farm as a whole and considers the multi-wakes effect on the same unit. As a result the loss of the velocity inside the wind farm is considered more exactly. Furthermore, considering the features of sequentially and self-correlation of wind speed, an auto-regressive and moving average (ARMA) model for wind speed is built up. Also the reliability model of wind farm is built when the output characteristics of wind power generation units, correlation of wind speeds among different wind farms, outage model of wind power generation units, wake effect of wind farm and air temperature are considered. Simulation results validate the effectiveness of the proposed models. These models can be used to research the reliability of power grid containing wind farms, wind farm capacity credit as well as the interconnection among wind farms

A Multiscale Wind and Power Forecast System for Wind Farms

A large scale introduction of wind energy in power sector causes a number of challenges for electricity market and wind farm operators who will have to deal with the variability and uncertainty in the wind power generation in their scheduling and trading decisions. Numerical wind power forecasting has been identified as an important tool to address the increasing variability and uncertainty and to more efficiently operate power systems with large wind power penetration. It has been observed that even when the wind magnitude and direction recorded at a wind mast are the same, the corresponding energy productions can vary significantly. In this work we try to introduce improvements by developing a more accurate wind forecast system for a complex terrain. The system has been operational for eight months for the Bessaker Wind Farm located in the middle part of Norway in a very complex terrain. Operational power curves have also been derived from data analysis. Although the methodology explained has been developed for an onshore wind farm, it can very well be utilized in an offshore context also.

An Evaluation of a Power Generation System with Photovoltaic and Wind Power using a Multi-Mode Power Generation Mix Model

The Government of Japan plans to expand photovoltaic and wind power drastically. However, since those power outputs fluctuate according to weather conditions, they may require additional load frequency control (LFC) capacity, thereby reducing efficiencies of thermal power generation. In order to evaluate these problems, we developed an optimal power generation mix model named as MM-OPG that deals with multiple modes of operation of each thermal power generation as well as the LFC constraint that the LFC requirements must be secured every moment. The model uses the hourly power demand curves and hourly power supply curves of renewables that are estimated from the actual data for 2010. The purpose of this study is to analyze the power generation mix in Eastern Japan in 2030 with a large penetration of photovoltaic and wind power. We conducted simulations using the model and obtained the following results. The case with the LFC constraint results in more frequent cutoffs of wind power that requires LFC capacity intensively, and an increase in pumped hydropower generation that provides the LFC, compared to the case without such constraint.

Robust LFC in a Smart Grid With Wind Power Penetration by Coordinated V2G Control and Frequency Controller

In the smart grid, the large scale wind power penetration tends to expand vastly. Nevertheless, due to the intermittent power generation from wind, this may cause a problem of large frequency fluctuation when the load-frequency control (LFC) capacity is not enough to compensate the unbalance of generation and load demand. Also, in the future transport sector, the plug-in hybrid electric vehicle (PHEV) is widely expected for driving in the customer side. Generally, the power of PHEV is charged by plugging into the home outlets as the dispersed battery energy storages. Therefore, the vehicle-to-grid (V2G) power control can be applied to compensate for the inadequate LFC capacity. This paper focuses on the new coordinated V2G control and conventional frequency controller for robust LFC in the smart grid with large wind farms. The battery state-of-charge (SOC) is controlled by the optimized SOC deviation control. The structure of frequency controller is a proportional integral (PI) with a single input. To enhance the robust performance and robust stability against the system uncertainties, the PI controller parameters and the SOC deviation are optimized simultaneously by the particle swarm optimization based on the fixed structure mixed H2/H∞ control. Simulation results show the superior robustness and control effect of the proposed coordinated controllers over the compared controllers.

An Approach for Wind Power Integration Using Demand Side Resources

Renewable energy resources, especially wind power, are expected to provide a considerable portion of the world energy requirements in the near future. Large-scale wind power penetration impacts the electricity industry in many aspects and raises a number of technical challenges for the electricity network. A day-ahead network-constrained market clearing formulation is proposed which considers demand side resources. The proposed approach can provide flexible load profile and reduce the need for ramp up/down services by the conventional generators. This method can potentially facilitate a large penetration of wind power by shifting the wind power generation from the off-peak periods to the high-peak hours. The validity of the proposed approach has been verified using the IEEE 30 bus and 57 bus test systems.