Including Wind Turbine Generators Research Articles

Novel Five-Phase Permanent Magnet Generator Systems for Wind Turbine Applications

This paper discusses the benefits of five-phase technology for applications including wind turbine generators. The performances of three-phase and five-phase permanent magnet generator (PMG) systems that use diode rectifier circuits are discussed. Investigations proved that the five-phase topology harnesses some specific and important benefits that are not provided by three-phase systems. The benefits include improved fault tolerance and reliability, and reduced voltage and torque ripple and size of DC link capacitor. These are general improvements that are sought after in many applications including renewable energy applications. The paper also discusses the design of a novel five-phase wind turbine generator which was optimised to make use of the key competitive advantages of our five-phase technology in renewable energy sector. Finite element (FE) and Matlab / Simulink are used in the investigations. Test results are also presented in this paper and used to validate simulations where possible.

Digital Twin as a Virtual Sensor for Wind Turbine Applications

Digital twins (DTs) have been implemented in various applications, including wind turbine generators (WTGs). They are used to create virtual replicas of physical turbines, which can be used to monitor and optimize their performance. By simulating the behavior of physical turbines in real time, DTs enable operators to predict potential failures and optimize maintenance schedules, resulting in increased reliability, safety, and efficiency. WTGs rely on accurate wind speed measurements for safe and efficient operation. However, physical wind speed sensors are prone to inaccuracies and failures due to environmental factors or inherent issues, resulting in partial or missing measurements that can affect the turbine’s performance. This paper proposes a DT-based sensing methodology to overcome these limitations by augmenting the physical sensor platform with virtual sensor arrays. A test bench of a direct drive WTG based on a permanent magnet synchronous generator (PMSG) was prepared, and its mathematical model was derived. MATLAB/Simulink was used to develop the WTG virtual model based on its mathematical model. A data acquisition system (DAS) equipped with an ActiveX server was used to facilitate real-time data exchange between the virtual and physical models. The virtual sensor was then validated and tuned using real sensory data from the physical turbine model. The results from the developed DT model showed the power of the DT as a virtual sensor in estimating wind speed according to the generated power.

Optimized cascaded controller for frequency stabilization of marine microgrid system

The trend towards reducing greenhouse gas emissions by dipping the use of traditional sources of energy in marine power grids, as well as the rapid expansion of renewable energy sources (RESs), were the driving forces behind the incorporation of RESs in maritime microgrid systems and enquiry of the ensuing prevalent control mechanism. The frequency stability of a Marine Microgrid System (MMGS) is a critical aspect that directly affects its reliable and efficient operation. This study describes a method for frequency stabilization in independent maritime microgrids consists of diverse renewable energy resources including wind turbine generators, sea wave energy/tidal power generation, solar generation, bio-diesel generator and energy storage systems. This paper aims to develop a new optimal cascaded order proportional integral based proportional derivative for marine load frequency control. Due to the fact that the performance of the controller is highly dependent on the parameters of the controller, optimizing these coefficients can have a significant impact on the output performance of the LFC control. In light of this, this paper presents the sewing training-based optimization (STBO), a new human-based metaheuristic algorithm to optimize the coefficient of the suggested controller. The essential stimulation of STBO is the teaching procedure of sewing to beginner tailors. By utilizing a population of candidate solutions, the algorithm iteratively refines the control parameters to find the optimal set that minimizes frequency deviations and enhances system stability. The responses of the cascaded PI-PD controller are linked to those of the PID and PI controllers in order to demonstrate its superiority. To evaluate the efficiency of STBO, it is compared to well-established recent techniques such as fitness dependent optimization, grey wolf optimization and Jellyfish search optimization. From the results, it is observed that our proposed approach improved the settling time by 25.35%, 45.89%, and 29.35%, reduced peak overshoot by 78.34%, 67.71%, and 78.23%, and similarly reduced undershoot by 81.56%, 56.22% and 76.56% as compared to FDO, GWO and JSO techniques respectively. Finally, the sensitivity analysis is performed under ±50% load variation and ± 40% power system parameters to prove the robustness of the proposed controller.

Model Predictive Control Based Voltage Regulation Strategy Using Wind Farm as Black-Start Source

A coordinated voltage regulation method based on model predictive control (MPC) is proposed in this paper for utilizing wind farms (WF) as black-start (BS) source to start up a thermal generating unit. The reactive power regulation devices with different dynamic response characteristics including wind turbine generators (WTGs), energy storage system (ESS), and static var generator (SVG) are coordinated by the proposed MPC to handle disturbances caused by ancillary machine start during the BS process. The reactive power sharing between WTGs is optimized to maximize the dynamic reactive power reserve. The capabilities of ESS and SVG in providing sufficient dynamic reactive power against disturbances are also fully exploited, which helps accelerate voltage recovery for low voltage ride through to avoid the tripping incidents of WTGs. The impact of active power on bus voltage variation due to low <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">X</i> / <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</i> ratio is also considered. The reactive power and active power of WTGs and ESS are coordinately controlled for handling voltage disturbance without harming frequency control. A WF with 33 WTGs rated 1.5 MW each is used in case studies to demonstrate the enhanced disturbance handling capability of the proposed voltage regulation strategy during BS progress.

Leveraging blockchain technology for resilient and robust frequency control in a renewable-based hybrid power system with hydrogen and battery storage integration

This paper introduces the blockchain-assisted frequency regulation mechanism for achieving resiliency and robustness in a renewable-based hybrid power system (HPS) powered by multiple sources, including wind turbine generators (WTG), hydrogen fuel cells (FC) with aqua electrolyzer (AE), diesel engine generators (DEG) and battery energy storage systems (BESS). Frequency fluctuations are exacerbated by load uncertainties paired with energy-generating source uncertainties resulting from integrating multiple distributed energy resources (DERs) into the national electric power grid. In the event of energy generation loss, efficient load frequency control (LFC) techniques are considered essential for frequency restoration in DER-integrated HPS. In addition, active power regulation data in LFC need secure data storage mechanisms for ensuring cyber-resilience, a transparent cash payout mechanism for the stakeholders in LFC market operation, and related sustainability services. A novel resilient blockchain framework for realizing LFC is proposed for addressing the power resilience and the false-data injection issue. Moreover, a parameter sensitivity algorithm (PSA) constrained optimization methodology using the genetic algorithm (GA) withstands the energy generation loss and uncertainties. A consensus algorithm-based blockchain methodology acts as an enabler for strategic decision-making and secures the data flow to the market operator. The proposed framework-driven methodology is implemented using a Blockchain network developed in python for securing LFC transactions by developing a case study for HPS. Numerous simulation scenarios demonstrate the proposed methodology's effectiveness in establishing a synergistic operative framework for the resilient and robust operation of the hybrid energy system with multiple sources, even in the event of uncertainties.

Negative sequence quantities-based protection under inverter-based resources [sbnd] Challenges and impact of the German grid code

Inverter-based Resources (IBRs), including Wind Turbine Generators (WTGs), exhibit different negative-sequence fault current characteristics compared to conventional synchronous generators (SGs). Depending on the type and control of IBR, their negative-sequence current contribution can be substantially lower in amplitude and different in phase. Therefore, large-scale integration of IBRs is expected to have a significant impact on negative sequence quantities-based protection elements including Instantaneous Negative Sequence Overcurrent (50Q), Negative Sequence Time Overcurrent (51Q), Directional Negative Sequence Overcurrent (67Q), and fault-identification FID scheme. This paper demonstrates misoperation of these functions in a practical multi wind park system. The misoperation problems are due to the wind parks with full scale converter (FSC) WTGs operating under traditional coupled sequence control (CSC). As illustrated in this paper, such misoperation problems can be eliminated effectively by utilizing a decoupled sequence control (DSC) scheme in FSC WTGs based on the recent VDE-AR-N 4120 Technical Connection Rules.

Impact of Inverter-Based Resources on Negative Sequence Quantities-Based Protection Elements

Inverter-Based Resources (IBRs), including Wind turbine generators (WTGs), exhibit substantially different negative-sequence fault current characteristics compared to synchronous generators (SGs). These differences may cause misoperation of customary negative-sequence-based protective elements set under the assumption of a conventional SG dominated power system. The amplitude of the negative-sequence fault current of a WTG is smaller than that of an SG. This may lead to misoperation of the negative-sequence overcurrent elements 50Q/51Q. Moreover, the angular relation of the negative-sequence current and voltage is different under WTGs, which may result in the misoperation of directional negative-sequence overcurrent element 67Q. This paper first studies the key differences between the WTGs and SG by comparing their equivalent negative-sequence impedances with SG's. Then, simulation case studies are presented showing the misoperation of 50Q and 67Q due to wind generation and the corresponding impact on communication-assisted protection and fault identification scheme (FID). The impact on directional element is also experimentally validated in a hardware-in-the-loop real-time simulation set up using a physical relay. Finally, the paper studies the impact of various factors such as WTG type (Type-III/Type-IV) and Type-IV WTG control scheme (coupled/decoupled sequence) to determine the key features that need to be considered in practical protection studies. The objective is to show potential protection misoperation issues, identify the cause, and propose potential solutions.

A Study on Capacity Credit and ESS Evaluation for WTG and Multi-ESS in Power System

This paper proposes a new method for evaluating Effective Load Carrying Capability (ELCC) and Capacity Credit (CC) of a power system including Wind Turbine Generator (WTG) combined with Multi Energy Storage System (ESS). The WTG can only generate electrical power when the wind is available. Because of the fluctuation of wind speed, WTG generates intermittent power. In the reliability viewpoint of power system, the intermittent power of WTG is similar to the probabilistic characteristics based on the on-off power due to the mechanical availability of conventional generators. Therefore, high penetration of WTG will cause difficulties in power system operation. The high penetration of numerous and large capacity WTG can risk the power system adequacy, quality, and stability. This study develops a new method to assess how much the penetration of WTG can be extended when WTG is combined with ESS. This paper demonstrates various case studies of ELCC and CC of a power system containing WTG combined with Multi ESSs using a model system similar to Jeju island power system in Korea.

에너지저장장치와 결합한 WTG를 포함하는 전력계통의 Capacity Credit 평가 및 ESS 적정규모 평가방안

This paper proposes a new method for evaluating Effective Load Carrying Capability(ELCC) and capacity credit(C.C.) of power system including Wind Turbine Generator(WTG) combined with Battery Energy Storage System(BESS). WTG can only generate electricity power when the fuel(wind) is available. Because of fluctuation of wind speed, WTG generates intermittent power. In view point of reliability of power system, intermittent power of WTG is similar with probabilistic characteristics based on power on-off due to mechanical availability of conventional generator. Therefore, high penetration of WTG will occur difficulties in power operation. The high penetration of numerous and large capacity WTG can make risk to power system adequacy, quality and stability. Therefore, the penetration of WTG is limited in the world. In recent, it is expected that BESS installed at wind farms may smooth the wind power fluctuation. This study develops a new method to assess how much is penetration of WTG able to extended when Wind Turbine Generator(WTG) is combined with Battery Energy Storage System(BESS). In this paper, the assessment equation of capacity credit of WTG combined with BESS is formulated newly. The simulation program, is called GNRL_ESS, is developed in this study. This paper demonstrates a various case studies of ELCC and capacity credit(C.C.) of power system containing WTG combined with BESS using model system as similar as Jeju island power system. The case studies demonstrate that not only reasonable BESS capacity for a WTG but also permissible penetration percent of WTG combined with BESS and reasonable WTG capacity for a BESS can be decided.

Applied Magnetism: A Supply-Driven Materials Challenge

Permanent magnets are important in many green energy technologies including wind turbine generators and hybrid-electric vehicle motors. For these applications, volume and weight are important factors driving the overall design, and therefore a high energy density, or energy product, is an important figure of merit. This quantity defines the magnetic energy contained in a given volume of material, and so higher energy density magnets enable smaller, lighter applications. Currently, the most powerful magnets suitable for commercial purposes contain rare earth elements (REE), usually neodymium and dysprosium in the neodymium-iron-boride class of magnets. However, for select applications, often requiring high temperatures, samarium cobalt is the alloy of choice. These magnets have energy densities several times greater than their nearest non-REE-based competitor, which for some applications is the defining factor in creating a viable device. The global supply of these REE is overwhelmingly produced in China, which in 2015 mined more than ten times as much as the next largest producer (Australia). Such market domination effectively creates a single source of supply, leaving industries which rely on REE consumption susceptible to price shocks and supply disruptions of these critical materials. Furthermore, this supply sensitivity may act as a drag on the adaptationmore » rate of green energy technologies, particularly for large-scale users.« less

Impact of PV/Wind/Diesel Hybrid System on the Distribution Networks – Fault Currents

The short circuit analysis secures the electrical power systems protection scheme. Thus, in turn ensures the power system reliability, safe mode of operation, and uninterruptable power supply. The impact of distributed generation on the power systems stability, power quality, and short circuit level is still unclear and uncertain. The different characteristics of each distributed generation type, such as synchronous generators, induction generators, power electronics inverters make it more complicated to assess. Studying the effect of the penetration of distributed generation on fault current level of existing distribution networks is crucial. This paper will examine the impact of implementing distributed generation mix, including wind turbine generators, photovoltaic, and diesel generators on the fault current level of the distributed network under study. The short circuit analysis is carried out on the IEEE 13-bus distribution test system using ETAP software. The simulation results are presented in a comparison between four cases, comparing the impact of the distributed generation mix on the fault current level at different levels of penetration. Moreover, a comparison showing the contribution of each distributed generation type separately as a percentage is presented. The selection of distributed generation technology and location has a significant impact on the fault current.

풍력발전기와 BESS를 결합한 전력계통의 공급신뢰도 기여함수

This paper presents a study on reliability assessment and new contribution function development of power system including Wind Turbine Generator(WTG) combined with Battery Energy Storage System(BESS). This paper develops and proposes new reliability contribution function of BESS installed at wind farms. The methodology of reliability assessment, using Monte Carlo Simulation(MCS) method to simulate sample state duration, is proposed in detail. Forced Outage Rate(FOR) considered probabilistic approach for conventional generators is modelled in this paper. The penetration of large wind power can make risk to power system adequacy, quality and stability. Although the fluctuation of wind power, BESS installed at wind farms may smooth the wind power fluctuation. Using small size system as similar as Jeju island power system, a case study of reliability evaluation and new proposed contribution function of power system containing WTG combined with BESS is demonstrated in this paper, which would contributes to BESS reliability contribution and assessment tools of actual power system in future.

Reliability Contribution Function considering Wind Turbine Generators and Battery Energy Storage System in Power System

Abstract: This paper presents a study on reliability assessment and new contribution function development of power system including Wind Turbine Generator(WTG) combined with Battery Energy Storage System(BESS). This paper develops and proposes new reliability contribution function of BESS installed at wind farms. The methodology of reliability assessment, using Monte Carlo Simulation (MCS) method to simulate sample state duration, is proposed in detail. Forced Outage Rate(FOR) considered probabilistic approach for conventional generators is modelled in this paper. The high penetration of wind power can make risk to power system adequacy, quality and stability. Although the fluctuation of wind power, BESS installed at wind farms may smooth the wind power fluctuation. Using similar size model system as Korea power system, a case study of reliability evaluation and new proposed contribution function of power system containing WTG combined with BESS is demonstrated in this paper, which would contributes to BESS reliability contribution and assessment tools of actual power system in future.

Study on Modeling and Simulating of Micro-Powers and Micro-Grid Construction

Micro-grid can effectively solve many problems caused by distributed generation connecting with grid, so many countries and regions pay more attention to the research and usage of the micro-grid. In this paper, modeling and simulating of micro-powers, including wind turbine generator model, fuel cell model, photovoltaic cell (PV) with MPPT (maximum power point tracking) model and diesel generator model, as well as the secondary load which can be equipped with the capacity of frequency modulation, are implemented with MATLAB/Simulink platform, and simulations are carried to prove the model rationality and validity. On this basis, a micro-grid with various energy sources and loads is built. By evaluating its capacity of maintaining power quality and quick recovery under load mutations and serious fault scenario, it is showed that the constructed micro-power and micro-grid models can simulate the practical situation well.

DFIG 풍력터빈이 연계된 전력계통의 CCT 영향분석

풍력발전시스템은 기존의 발전시스템과 매우 다르다. 그러므로 전력계통에 풍력시스템을 연계하기 위해서는 동적특성에 대한 연구가 필요하다. 풍력발전기의 안정도해석은 전력계통의 운영에 있어서 중요 쟁점이다. 기존의 동기발전기만으로 구성된 전력계통의 위상각 안정도는 풍력발전기가 포함되면 그 결과가 달라진다. 즉, 풍력터빈에 연계된 발전기는 대부분 비동기인 유도발전기이기 때문이다. 위상각의 동기화 여부로 판별하는 위상각 안정도는 임계고장제거시간(CCT)을 계산하여 평가한다. 계통해석용 풍력터빈의 모델은 다양하여 그 해석에 어려움이 있으나 지금은 크게 4가지 타입으로 표준화가 되어있다. 본 논문에서는 PSS/E-32에서 제공하는 풍력터빈의 3번째 표준모델인 DFIG(Doubly-Fed induction Generator)모델을 이용하여 풍력단지가 연계된 전력계통의 CCT를 풍력단지의 위치와 용량을 고려하여 분석한다. Wind generation systems are very different in nature from conventional generation systems. Therefore it is necessary to research dynamic characteristics of wind generation systems connected to a power system. The stability analysis of wind turbine generator is an important issue in the operation of the power system. The result of angular stability of the power system that consists of only synchronous generators is different from that of the power system including wind turbine generators. This is due to the fact that generators connected to wind turbines are generally induction generators. The angular stability assessing synchronization of generators is determined by its corresponding critical clearing time(CCT). Wind turbine models for the analysis of power system are varied and difficult to use, but now these are standardized into four types. In this paper, the analysis of the CCT of the power system connected to wind farm considering the location and capacity is performed by using DFIG(Doubly-Fed induction Generator) wind turbine built-in type3 model in PSS/E-32.

DSM Considered Probabilistic Reliability Evaluation and an Information System for Power Systems Including Wind Turbine Generators

This paper proposes a methodology for evaluating the probabilistic reliability, considering demand side management (DSM) and Web based on a daily interval reliability information system for a grid constrained composite power system including wind turbine generators(WTG). The proposed model can consider capacity limitations and transmission line unavailabilities and the operation of WTG modeled by multi-states. The importance of renewable energy sources is growing at a rapid rate due to environmental concerns. A web based online daily time interval reliability integrated information system (WORRIS) is applied using the methodology proposed in this paper. This paper describes the architecture of the WORRIS Version 7.0 system.

Probabilistic Reliability Based Grid Expansion Planning of Power System Including Wind Turbine Generators

This paper proposes a new methodology for evaluating the probabilistic reliability based grid expansion planning of composite power system including the Wind Turbine Generators. The proposed model includes capacity limitations and uncertainties of the generators and transmission lines. It proposes to handle the uncertainties of system elements (generators, lines, transformers and wind resources of WTG, etc.) by a Composite power system Equivalent Load Duration Curve (CMELDC)-based model considering wind turbine generators (WTG). The model is derived from a nodal equivalent load duration curve based on an effective nodal load model including WTGs. Several scenarios are used to choose the optimal solution among various scenarios featuring new candidate lines. The characteristics and effectiveness of this simulation model are illustrated by case study using Jeju power system in South Korea.

BULK ELECTRIC SYSTEM RELIABILITY EVALUATION WITH WIND TURBINE AND ENERGY STORAGE

This paper describes a new methodology for grid expansion planning considering the probabilistic reliability of a Bulk Electric Systems (BES) including Wind Turbine Generators (WTG) and Energy Storage System (ESS).The proposed model includes the main parameters used to create an operational history for each individual unit and transmission line unavailability. Bulk electric system reliability analysis associated with wind energy provides an opportunity to investigate the reliability benefits when large-scale wind power is injected in a BES. High wind power penetration can lead to high risk levels in the overall system reliability. The impacts of different wind turbine penetration levels on the reliability benefits from ESS are analyzed when the WTG capacity is utilized to replace the conventional generators with same total rated power capacity. The WTG and ESS capacity are installed to meet the annual growth of load demand and maintain the BES adequacy levels. The proposed method is applied to the IEEE Reliability Test System (IEEE– RTS ).

Probabilistic Reliability Evaluation of Composite Power Systems Including Wind Turbine Generators

This paper proposes a new methodology for evaluating the probabilistic reliability of a grid constrained composite power system including wind turbine generators(WTG). The proposed model can consider capacity limitations and transmission line forced outage rates. The importance of renewable energy sources has been growing at a high rate as a result of being environment friendly. In particular, wind energy is one of the most successfully utilized such source to produce electrical energy. The random nature of wind speed can be incorporated in the evaluation by representing the WTG by multi state models. A simple case study shows in detail how it is used to perform a reliability evaluation study in proposed model.

Reliability-Based Grid Expansion Planning of Power Systems Considering Wind Turbine Generators

AbstractThis paper describes a new methodology for grid expansion planning considering the probabilistic reliability of a composite power system including wind turbine generators (WTG). The proposed model includes capacity limitations and transmission line unavailability. The importance of renewable energy sources has been growing at a rapid rate due to environmental concerns. In particular, wind energy is one of the most successfully utilized such source in producing electrical energy. The random nature of wind speed can be incorporated in the evaluation by representing the WTG as a multi-state model. This type of model comes from a nodal equivalent load duration curve based on a nodal effective load model developed in recent years. In this paper, a heuristic method is used to search for the best reliability level among various scenarios with candidate lines.