Repair Strategies for Wind Turbines

Abstract The explicit finite element (FE) simulation method of the flexible rotor with fan blade off (FBO) is developed using LS-DYNA. Three important aspects model processing have been discussed, including setting and rotational speed, bearings, solution time reduction technologies. An inner cross to simulate elastic which can effectively avoid problems existing methods. Based on established FE model, dynamic response, stress distribution characteristics, impact energy propagation shaft are studied after FBO fault occurs. numerical results show that missing does not propagate as a wave in rotating shaft, different from non-rotating beam. gyroscopic effect inhibit typical characteristics energy. bending moment determined by both unbalanced load, while load dominant factor. Finally, it analyzed key factors such unbalance, constraints fusing structure casing effects response rotor. concentration phenomenon amplification reaction force appear off.

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Repairing a shear web of a wind turbine rotor blade by bridging over defects with pre-fabricated plates instead of removing and replacing the entire shear web. The plates are bonded to the lateral sides of the shear web around the defect to bridge it. This reduces repair time and costs compared to manual repairs. The plates mimic the shear web's layup to maintain strength. After bonding, vacuum is applied to press the plates against the web, then heat cures the adhesive.

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A system and method for replacing worn gear teeth in wind turbine pitch systems without removing the entire gear. The method involves using a tool jig with indexing features matching the gear tooth spacing. The jig is placed on the gear top surface guided by the indexing features. A removable tool is attached to the jig and positioned to remove the worn tooth. The tool removes the tooth guided by the jig rails to create a smooth cut surface. The tool is then removed and the jig detached to leave the gear with a replacement tooth.

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Split-shaft wind turbines decouple the turbines shaft from generators shaft, enabling several modifications in drivetrain. One of significant achievements a split-shaft drivetrain is reduction size excitation circuit. The grid-side converter eliminated, and rotor-side can safely reduce its to fraction full-size excitation. Therefore, this low-power-rated operates at low voltage handles regular operations well. However, fault conditions may expose weaknesses push it limits. This paper investigates effects reduced-size on ride-through capabilities required all turbines. Four different protection circuits, including active crowbar, crowbar along resistorinductor circuit (C-RL), series dynamic resistor (SDR), new-bridge current limiter (NBFCL), are employed, their investigated compared. Wind turbine controllers also utilized impact faults power electronic converters. effective method store excess energy rotor. proposed low-voltage strategies simulated MATLAB Simulink (2022b) validate results demonstrate effectiveness functionality.

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Method for forming or repairing overhung sections like flared tips on turbomachine parts like turbine blades without needing to replace them. The method involves sequentially layering material on the part in a non-coplanar orientation to approximate the shape of the overhung section. This is followed by machining the layered material to form the final overhung section. The layering can be done using techniques like welding or additive manufacturing.

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The intentional yaw offset of wind turbines has shown potential to redirect wakes, enhancing overall plant power production, but it may increase fatigue loading on turbine components. This study analyzed loads the NREL 5 MW reference under varying offsets using blade element momentum theory, dynamic momentum, and converging Lagrange filaments vortex method, all implemented in OpenFAST. Simulations employed angles from 40 40, with turbulent inflow generated by TurbSim, an OpenFAST tool for realistic conditions. Fatigue were calculated according IEC 61400-1 design load case 1.2 standards, thirty simulations per angle across five speed bins. Damage equivalent was evaluated via rainflow counting, Miners rule, Goodman correction. Results showed that free modeling unsteady aerodynamic forces, yielded distinct differences damage compared method yawed predicted lower low-speed shaft bending moment at negative offsets, attributed its improved handling effects reduce variations. Conversely, above 20, indicated higher torque, reflecting accurate capture loading. These findings highl... Read More

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In an on-shore horizontal axis wind turbine (HAWT), during normal operation, the key contributor to fatigue damage of tower is aerodynamic thrust transferred it through yaw bearing. this paper, a vibration isolation based approach with linear generator as damper used reduce these loads coming onto tower. concept, along spring in parallel introduced between top and rotor-nacelle assembly (RNA). WindPACT1.5 MW considered for study. Optimal isolator design parameters, stiffness, damping, etc. are obtained parametric studies using in-built simplified aeroelastic MATLAB model. Comparison short-term equivalent (DEL) tower, fore-aft oscillations tower-top presented without isolator. A reduction base forces achieved: 2075% near cut-in cut-out speed, 020% rated speed.

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Method to efficiently service a wind turbine component like a power converter without replacing the entire component when a subcomponent fails. When a subcomponent fails, the component memory is read from the malfunctioning subcomponent using a dedicated link. This memory contains specific component information. The component memory is then written to the replacement subcomponent over another dedicated link. This allows tracking failure rates without swapping the entire component. It involves physically modifying the replacement subcomponent to enable writing.

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Due to the development trend towards large-scale wind turbines with ultra-long blades, risk of blade-tower collision has increased significantly, making prevention a critical engineering task. As clearance is most crucial indicator for evaluating risk, it necessary study variation laws, particularly under conditions where may drop below safety threshold. Among these conditions, aerodynamic imbalance common and nonnegligible one. Since directly reflects motion states offers potential diagnosing imbalances. In this study, coupled analysis model 5 MW onshore turbine imbalances was developed. The time series one normal operational condition four typical were obtained through numerical simulations. effects on analyzed statistically. Afterwards, fault diagnosis based MultiRocket algorithm proposed. performance robustness proposed validated comparisons other commonly used algorithms. This deepens insights into laws provides precise

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Wind turbine gearboxes are critical components in wind energy systems but highly susceptible to mechanical failures due high loads, variable operating conditions, and material fatigue. This study presents an integrated approach utilizing condition monitoring (CMS), predictive maintenance algorithms, finite element analysis (FEA) enhance gearbox reliability. By analyzing stress distribution, vibration, temperature trends, we establish a robust methodology for early fault detection. Our results show that artificial intelligence (AI)-based can reduce unplanned by 40% increase overall efficiency 20%. provides insights into optimizing operation through data-driven strategies.

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A system for extracting seized yaw pistons from wind turbine housing to enable repair and maintenance of yaw systems. The system uses three specialized portable power tools for removing stuck yaw pistons that have become seized due to damage, dirt, grease, or deformation into mushroomed piston rings. The tools and components are designed to safely and efficiently extract seized yaw pistons from their housing when conventional tools can't reach or remove them.

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An offshore floating intervention platform that can temporarily dock onto deep-water offshore wind turbines for maintenance and repairs. The platform has a protruding heave plate that engages the turbine platform below. Ballast can be added/removed to lift/lower the heave plate for docking. The platform has a ballasting/de-ballasting unit to control vertical position. This allows access to deeper water wind farms where conventional bottom-mounted platforms are impractical.

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A universal wind turbine blade handling system that allows easy access to the blade surface for treatment and reduces risks compared to enclosed blade carts. The system has an adjustable support frame with multiple vertical pillars and moveable pads. Blades can be placed on the frame at any location along the span. The pads adjust independently to fit the blade shape and size. This exposes the blade surface for treatment without obstruction from the frame. The system can be programmed for different blade types and sizes.

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Abstract In this paper, the turbine power simulator operates at a speed below its bending critical speed. However, imbalance within rotor generates vibrations, preventing from reaching working To address issue, dynamic balancing experimental study is conducted. Initially, low-speed of performed near first-order Subsequently, utilizing dual-plane influence coefficient technique, high-speed test system successfully carried out on rig. After field test, rotors vibration significantly reduced, with efficiency exceeding 83% for all cases, demonstrating excellent vibrational characteristics and remarkable effects. The research presented in paper offers an effective approach controlling similar rotors, thus holding considerable engineering application value.

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Abstract Taking a typical turbine as an example, the feasibility of blade damage diagnosis based on vibration response in operation is verified. Firstly, rigid flexible coupling dynamic model was established by using multi-body dynamics software. The under obtained taking random wind spectrum excitation, and verified comparing it with measured data. Then, added to model, acceleration before after sensor points arranged at different positions various conditions compared. Based data, sensitivity law its internal explored, then optimal layout direction position sensors are determined. research results indicate that changes blades operating can reflect damage. Additionally, chordwise responses measurement near top middle more sensitive It be used preferred location for identify

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In-place bearing replacement method for wind turbine main shafts without disassembling the entire drive train. It involves using a crane to lift the shaft to a clearance height, removing the old bearing, installing a split bearing with separate semi-circular components, and then lowering the shaft back into position. This allows bearing replacement uptower without removing the entire drive train. A rotor lock prevents shaft rotation during lifting. The split bearing design allows disassembly and installation in sections.

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With the increasing capacity of wind turbines, key components including rotor diameter, tower height, and radius expand correspondingly. This heightened inertia extends response time pitch actuators during rapid speed variations occurring above rated speed. Consequently, turbines encounter significant output power oscillations complex structural loading challenges. To address these issues, this paper proposes a novel control strategy combining an effective estimation with inverse system method. The developed aims to stabilize rotational despite fluctuations. Central approach is aerodynamic torque using extended Kalman filter (EKF) applied drive train model. estimated then utilized compute at plane via differential Leveraging estimate, technique transforms nonlinear turbine dynamics into linearized, decoupled pseudo-linear system. linearization facilitates design more agile controller. Simulation outcomes demonstrate that proposed markedly enhances speed, diminishes oscillations, alleviates loads, notably base. These improvements bolster operational safety stability under above-rated ... Read More

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Repair device for wind turbine bearings with damaged teeth that enables maintaining torque transfer between the motor and the damaged bearing without replacing the entire bearing. The repair device has a carrier aligned with the damaged teeth and a gear train mounted on it. The gear train includes a drive gear connected to the motor, idler gears between the drive gear, and pinion gears meshed with the damaged and undamaged teeth of the bearing. This allows the motor torque to be transferred to the undamaged teeth instead of the damaged ones.

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Wind turbines experience significant vibrations due to fluctuating wind loads, which can impact structural integrity and operational efficiency. This study examines the effectiveness of Pendulum Tuned Mass Dampers (PTMDs) for mitigating these vibrations. Two types force inputs were analyzed: a sinusoidal function representing periodic fluctuations random simulating turbulent effects. Numerical simulations conducted evaluate influence mass ratios (0.01, 0.02, 0.05) damping (0.1, on vibration suppression. The results indicate that installation PTMD reduce from 45% 91% under varying operating conditions. optimum suppression up was achieved when ratio 0.02 0.01 excitation. A 0.05 also led decrease 54% in nacelle oscillations, confirming promoting stability. An optimal found effectively balance energy dissipation stability, preventing excessive oscillations maintaining system These findings confirm integrating enhance turbine performance by reducing fatigue loads extending lifespan. By optimizing parameters, engineers achieve better control, improving stability durability underscores impo... Read More

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Automated composite part repair system using a robot with interchangeable end effectors for inspection and repair tasks. The system allows robotic inspection, damage removal, repair patch placement, and surface preparation using an atmospheric plasma tool. The robot can switch between different end effectors like plasma preparation, imaging, scanning, and machining. It uses 3D modeling to coordinate actions with the part inside the cell. The plasma tool increases surface energy for bonding. The system enables automated composite part repair and verification.

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