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Wind energy is known as one of the most efficient clean renewable energy sources and has attracted extensive research interests in both academic and industry fields. In this study, the effects of turbulent wind and voltage disturbance on a wind turbine drivetrain are analyzed, and a wind turbine drivetrain dynamic model combined with the electric m...
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Citations
... It was shown from the study of the mean-to-alternating force ratio that the external excitation has more effect than internal excitations on the torsional vibrations of the wind turbine gearbox components. Li et al. [28] studied the effects of turbulent wind and voltage disturbance on a wind turbine drivetrain by combining the drivetrain dynamic model with the electric model of a doubly fed induction generator. The model accounted for the dynamic interaction between turbulent wind, voltage disturbance, and mechanical system to compute the system modes. ...
Planetary gearsets are widely used in several mechanical systems and have numerous advantages over counter-shaft gears. Despite this, the complex arrangement of components in a planetary gear system makes them susceptible to noise and vibration issues. An exhaustive and rich literature is available on the topic of planetary gear dynamics, but most of these studies consider only the parametric excitation of gear mesh contacts while assuming an ideal power source. But contrary to this popular assumption, realistic power sources (IC Engine, electric motor, wind turbine, etc.) could be subjected to torque fluctuations based on the operating conditions. The current study presents a theoretical investigation on the load distribution and dynamic behavior of planetary gear sets subjected to both internal and external excitations. A three-dimensional dynamic planetary load distribution model that inherently captures the internal excitation due to the elastic gear mesh contacts is employed in this study. The influence of operating conditions on both system-level response and local gear mesh contact stress distribution are explored. Discussed results not only illustrate the potential of the dynamic model but also reinforce the need for such computationally efficient models for design and analysis purposes.
... Within the drivetrain, it is hard to provide enough torsional damping [55] that is further weakened by the direct power control strategy [56], and thus the long-term torsional vibration is caused by the changeable operating torque. Inevitably, under the unsteady wind field, the higher wind speed increases the vibration of drivetrain components [57], and the wind disturbance enlarges the variation scope of meshing force in geared drivetrains [58]. ...
... Except for mechanical loads, the electric disturbance, such as voltage disturbance, also excites adverse vibration on drivetrains [58], because it brings about the fluctuation of generator electromagnetic torque that even causes more serious vibration compared to mechanical torque [69]. Another explanation is that the electric disturbance worsens the effective damping for the electro-mechanical oscillation [70]. ...
... According to excitation sources in generators, mitigation approaches consist of increasing the air gap length, isolating the stator frame from its core, and introducing the damping into the generator rotor and stator winding [150]. Besides, with the increase of resistance within generators, the maximum meshing force will be reduced, and hence internal excitations are also suppressed [58]. ...
Wind energy is an important sustainable energy to achieve carbon neutrality. To capture maximum wind energy, wind turbine sizes sharply increase and turbines work under more complicated conditions as well as loads, especially for offshore applications. As critical components to transfer wind power into electric energy, drivetrains of wind turbines inevitably face challenges of higher vibration and noise. However, under the new situation there is a gap in comprehensive review and summary on the vibration and noise of wind turbine drivetrains. According to the above problems, this paper focuses on wind turbine drivetrains, and reviews the vibration and noise from a systematic perspective of “generation-analysis-reduction”. The generation is analyzed from aspects of sources to transfer, and advanced methods for in-depth analysis are compared. Moreover, state-of-the-art reduction technologies are covered and summarized based on the innovative classification framework with a three-level hierarchy formed by source suppression, transfer path optimization, and control intervention. Further, a full discussion is presented and thus attractive research prospects are recommended. It is concluded that opportunities and challenges coexist in the design and application of large wind turbine drivetrains considering vibration and noise, and expected that this paper can provide a general reference for related research.
... These disturbances, as mentioned in [22], and [23], can be the result of the tower shadow effect when the blades cross in front of the tower, or by wind shear, caused by a nonuniform entry of wind in magnitude and position. In addition, in [24] refers to the effect of wind speed turbulence that generates vibrations in the gearbox system. ...
Resumen:
Esta investigación propone una metodología de control aplicada a una técnica en Sistemas de Generación de Energía Eólica (WEGS) para el Seguimiento del Punto de Máxima Potencia (MPPT) basada en un observador Fuzzy y complementada con un controlador PI mediante el método de Control Directo de Velocidad (DSC). Este enfoque permite controlar la corriente de referencia del lado del rotor a través de las variaciones de par y potencia eléctrica en un modelo de Generador de Inducción Doblemente Alimentado (DFIG). En consecuencia, la velocidad del generador se controla para obtener una respuesta rápida del máximo Coeficiente de Potencia (). La construcción de esta estrategia comienza con mediciones directas de las variables eléctricas y mecánicas utilizando herramientas computacionales como FAST y Matlab-Simulink para las simulaciones del modelo del aerogenerador. Esta estrategia DSC presenta un rápido desempeño en el seguimiento del considerando la dinámica de un aerogenerador de 1,5MW; esta estrategia ha sido comparada con un controlador PI tradicional mejorando la extracción de la potencia de salida.
... Bartelmus et al. [10] studied the vibration response of gearboxes subjected to varying loads and investigated the relationship between the load values and diagnostic features. Li et al. [11] investigated the contributions of voltage disturbance, turbulent wind and design parameters to the wind-turbine drivetrain dynamics. In these studies, one of the standard assumptions was that the variations of the gear rotation speeds with time are prespecified. ...
... k t (t = 1, 2, . . . , 5) and k rt denote the torsional stiffness of shaft t and the internal ring gear, respectively; c t and c rt denote the torsional damping, which can be calculated by the empirical formulas [11]. T L and T e denote the load torque acted on the load device and the electromagnetic torque generated by the driving motor, respectively. ...
For the better design and monitoring of gearboxes operating under nonstationary conditions, the dynamic interaction behavior of an electric motor drive multistage gear set is investigated in this study. Initially, dynamic mathematical models of an asynchronous motor and a multistage gear set are established by using the equivalent circuit method and the lumped parameter method, respectively. An electromechanical model coupling the asynchronous motor and the gearbox is subsequently developed, which is suitable for nonstationary conditions. The system transient responses under an impact external load are analyzed, and the mechanical torsional-vibration and electric current response are compared. Finally, the dynamic load propagation mechanism and the interaction effect on different gears are examined. The results demonstrate that the vibration frequencies of the multistage gearbox in steady and transient states both can be captured in the current. Electric current can be applied to reflect the external load variation and the internal vibration status of the driven gearbox under stationary or nonstationary conditions. The mutual excitation effects between adjacent gear pairs change the respective dynamic characteristics of the gears, and gears with small nominal loads are susceptible.
... A parametric study is performed to understand the influences of generator and gearbox parameters on the drivetrain system dynamics. 4 In the paper ''Dynamical analysis of fractional order model of immunogenic tumors,'' Sadia Arshad, investigate the fractional order model of the cytotoxic T-lymphocyte response to a growing tumor cell population. They show that tumor growth rate, source rate of immune cells, and death rate of immune cells play vital role in tumor dynamics, and the system undergoes saddlenode and transcritical bifurcation based on these parameters. ...
... A parametric study is performed to understand the influences of generator and gearbox parameters on the drivetrain system dynamics. 4 In the paper ''Dynamical analysis of fractional order model of immunogenic tumors,'' Sadia Arshad, Dumitru Baleanu, Jianfei Huang, Yifa Tang, and Maysaa Mohamed Al Qurashi investigate the fractional order model of the cytotoxic T-lymphocyte response to a growing tumor cell population. They show that tumor growth rate, source rate of immune cells, and death rate of immune cells play vital role in tumor dynamics, and the system undergoes saddlenode and transcritical bifurcation based on these parameters. ...
... El avance de la tecnología, especialmente en el desarrollo de ordenadores más potentes con mayor capacidad de cómputo y almacenamiento, ha impulsado el modelado y desarrollo de herramientas numéricas versátiles para estudiar el comportamiento multifísico de turbinas eólicas. Como ejemplo se puede mencionar el trabajo de Gong y Qiao (2010) quienes combinaron FAST y Simulink con el objetivo de simular la respuesta dinámica del generador de una turbina eólica (Wind Turbine Generator, WTG) en tres escenarios diferentes: condiciones normales, desbalance en una pala, y asimetría aerodinámica; la plataforma de simulación híbrida HAWC2 + Matlab/Simulink desarrollada por Barahona et al. (2010) destinada a la simulación, diseño, estudio y análisis integral de turbinas eólicas; y más recientemente, el trabajo de Li et al. (2016) el cual aborda el modelado eléctrico, mecánico y aerodinámico de una turbina eólica de 1 MW de potencia. ...
La generación de energía eléctrica a partir del aire en movimiento es considerada actualmente la tecnología más prometedora en cuanto a su contribución a la matriz energética de países con grandes recursos eólicos. Este hecho se ve reflejado por el continuo incremento en el tamaño y la capacidad de los aerogeneradores: desde rotores de 15 m de diámetro y una potencia nominal de 0.05 MW hasta las grandes turbinas eólicas de eje horizontal (Large Horizontal-Axis Wind Turbines, LHAWT) con rotores superiores a los 120 m de diámetro y potencia aproximada de 8 MW. Un diseño eficiente de estas grandes máquinas rotantes debe involucrar, indefectiblemente, un enfoque holístico que incluya los múltiples campos físicos intervinientes, tales como: i) aerodinámica; ii) hidrodinámica (turbinas emplazadas en el océano); iii) dinámica estructural; iv) dinámica eléctrica; y v) control. En este trabajo se presentan los aspectos teóricos relacionados al modelado y diseño de una plataforma numérica de cosimulación destinada al análisis integral de LHAWTs. Específicamente, en esta primera etapa, el sistema dinámico bajo estudio es particionado en tres subsistemas: i) un modelo multicuerpo rígido para la estructura de la turbina; ii) un modelo aerodinámico basado en el método de red de vórtices no lineal e inestacionario (Unsteady Vortex-Lattice Method, UVLM) para estimar las cargas sobre las palas de la turbina; y iii) un modelo de máquina síncrona de imanes permanentes para el control del generador y el monitoreo de condición. Los tres subsistemas intercambian información bidireccionalmente mediante un esquema de acoplamiento fuerte. Finalmente, se presenta la implementación computacional del marco de co-simulación propuesto y el esquema numérico para integrar todas las ecuaciones gobernantes en el dominio del tiempo.
In this paper, we consider the hybrid time switching (TS) and power splitting (PS) simultaneous wireless information and power transfer (SWIPT) protocol design in massive MIMO system. In this system, the base station (BS) simultaneously serves a set of half-duplex (HD) sensor nodes which are uniformly distributed in its coverage. The whole protocol can be divided into two phases based on the idea of TS. The first phase is designed for sensor nodes energy harvesting as well as downlink training. During this phase, the BS transmits energy signals to the sensor nodes. Based on the idea of PS, the sensor nodes utilize the received energy signals for energy harvesting and downlink channel estimation. In the second phase, the BS schedules the sensors intelligently based on the beam-domain distributions of channels to mitigate interference between sensors and enhance transmission spectral efficiency. Then, the BS forms the receive beamformers for the reception of signals transmitted by sensors. By optimizing transmit powers at the BS and the TS ratio, the system achievable sum rate performance is maximized. Simulation results show the superiority of the proposed protocol on spectral efficiency compared with conventional massive MIMO SWIPT protocol.
The economic emission dispatch (EED) problem aims to control generation cost and reduce the impact of waste gas on the environment. It has multiple constraints and nonconvex objectives. To solve it, the collective neurodynamic optimization (CNO) method, which combines heuristic approach and projection neural network (PNN), is attempted to optimize scheduling of an electrical microgrid with ten thermal generators and minimize the plus of generation and emission cost. As the objective function has non-derivative points considering valve point effect (VPE), differential inclusion approach is employed in the PNN model introduced to deal with them. Under certain condition, the local optimality and convergence of the dynamic model for the optimization problem is analyzed. The capability of the algorithm is verified in a complicated situation, where transmission loss and prohibited operating zones are considered. In addition, the dynamic variation of load power at demand side is considered and the optimal scheduling of generators within 24 hours is described.
This paper presents a framework to deal with distributed optimization problems composed by binary and continuous variables. Instead of using a mixed integer quadratic programming (MIQP), the approach proposed here transforms the MIQP into a set of quadratic programming's (QP) that are easier to solve. In this way an instance of the controller related to each feasible combination of binary variables is created. The distributed controller performs an iterative process where the set of agents must agree on the value of continuous interconnection variables, while each agent must decide the values of local binary variables. During the iteration procedure the instances are rated according to a performance index and the instances with best performance are selected until the best one is obtained. The proposed methodology is applied to economic optimization of networked microgrids.
