Generator For Wind Turbine Application Research Articles

A Counter-Rotating Double-Rotor Axial Flux Permanent Magnet Generator for Wind Turbine Applications: Design, Simulation, and Prototyping

A Counter-Rotating Double-Rotor Axial Flux Permanent Magnet Generator for Wind Turbine Applications: Design, Simulation, and Prototyping

Active disturbance rejection control of a permanent magnet synchronous generator for wind turbine applications

With sight on maximizing the amount of energy that can be extracted, by a wind turbine, from the wind, this article solves the maximum power point tracking problem for a permanent magnet synchronous generator-based horizontal wind turbine connected to the electrical grid. A three-phase back-to-back converter, which allows a decoupling between the electrical grid and the generator, is employed as an interphase between the wind turbine and the utility grid. Based on the mathematical model in the synchronous reference frame and taking advantage of the differential flatness property the system exhibits, controllers based on the active disturbance rejection methodology are designed, in this work, to track the curve of maximum extracted power from the wind and manage the generated electricity into the grid. At the same time, the phase angle of the electricity generated is synchronized with the phase angle of the electrical grid. Numerical simulations are performed to support the controllers presented in this work.

A solution to reduce overheating and increase wind turbine systems availability

The ever-increasing demand for electrical power and the tremendous growth of renewable energy sources in the past decade has led designers to design wind turbine system components for optimal performance. Cost optimization, weight reduction, higher performances, and lower non-conformance cost are a few expectations that components are expected to meet in the present market condition. Wind turbine system unavailability impacts the annual energy production of the wind turbine. Overheating of the wind turbine system components is one of the main challenges to overcome. For the heating analysis, we discuss the wind turbine generator as a specific example in this article. This approach is equally valid for other components of wind turbine systems, with heat exchanger. Windings and bearings are the two main components susceptible to failure in the generator for wind turbine applications. The root cause may vary from case to case, but overheating accelerates the generator’s windings and bearing failure and in many cases is the prime reason behind. Running the components at higher load points is one of the reasons for components to overheat. The article presents a solution to improve the performance of the wind turbine system and at the same time making it a commercially attractive choice. This can be achieved by reducing generator windings and bearings operating temperature, and also reducing its cost and weight at the same time. The proposed solution to reduce overheating is achieved and verified through results. The achieved results also explain how one solution is advantageous over the other.

Measuring MNm torques as part of a prototype testing campaign of a high-temperature superconducting generator for wind turbine application in the scope of the Ecoswing project

Modern wind turbines have a driving torque in the range of up to 10 MNm. The measurement of such high torques poses challenges, as there is no standard measurement equipment for this torque level available today. During the EU funded EcoSwing project, the world’s first superconducting low-cost and lightweight multi-megawatt wind turbine generator has been designed and tested on the DyNaLab nacelle test rig of Fraunhofer IWES. For this test campaign, a specifically designed torque measurement system has been developed to measure the torque directly at the flange of the device under test in order to evaluate the efficiency of the power train.

Performance comparison of 1X versus 4X HTS tapes toward the design a 10‐MW direct drive HTS generator for wind turbine applications

AbstractWith current developments underway at the University of Houston, 4× high‐temperature superconducting (HTS) yttrium barium copper oxide (YBCO) tapes are expected to reach a fourfold critical current density improvement at 30 K and 3 T as part of an Advanced Research Projects Agency‐Energy (ARPA‐E)‐sponsored project. The impetus for this project is to develop and deploy cost‐effective direct drive HTS generators for large offshore wind turbine generators. The improved conductor performance of 4× tapes over 1× tapes is projected to allow for a significant reduction in the amount of HTS tapes required to generate the excitation field and, thus, lead to a reduction of the overall generator cost. It was, however, deduced from simulation results that conventional methods of rotor field enhancement using rotor iron makes 1× conductor competitive enough compared with 4× conductors; hence, commercially available YBCO tapes can provide all the energy density requirements to make wind turbines a competitive energy resource based on energy forecasts. This paper is a presentation of design and optimization work to find the best generator topology from the point of view of both machine design and electricity supply. The generators are numerically modeled and simulated using 1× and 4× YBCO HTS conductors on either or of both the rotor and stator side of the generators.

Design of a three-phase multistage axial flux permanent magnet generator for wind turbine applications

Presently, axial flux permanent magnet machines are becoming popular and are being deployed actively for low speed applications. This paper presents an improved model of a multistage axial flux permanent magnet generator (AFPMG). The multistage AFPMG consists of multiple stator and rotor discs. There are three identical 1-phase stator discs and four in-phase rotor discs in the proposed multistage AFPMG. In this research, 4 case studies were analyzed on the design of the multistage AFPMG. First, a phase shift model (PSM) positions the three 1-phase stator discs to behave as a 3-phase generator. Actually, the PSM computes phases for three stator discs in order to establish phase shift of 120$^{\circ}$ between each two phases. The implementation of the presented model in the multistage AFPMG reduces the diameter of the stator disc three times as compared to the conventional 3-phase AFPMG with identical rated specifications. Second, the voltage waveform of the AFPMG was analyzed for harmonic contents and the percentages of 3rd and 5th harmonics were computed. The test results show that 3rd and 5th harmonics were reduced to 10.7% and 0.54%, respectively, in voltage waveform. Third, the proposed multistage AFPMG was designed considering begin-to-end winding connections of the stator disc. While adopting begin-to-end connection, the number of poles of the AFPMG are doubled, which ultimately increases air-gap flux density and thus the terminal voltage of the stator disc and operating shaft speed is halved. The test results show that the torque-to-weight ratio parameter of the designed AFPMG was improved by using a begin-to-end connection for the stator disc. Fourth, the increased air-gap flux density also improves the power density parameter of the AFPMG with a begin-to-end winding connection. Moreover, a prototype model of a 1200-W multistage AFPMG was designed and fabricated while following PSM and begin-to-end winding connection and tested. Thus the test results verify the proposed model of the multistage AFPMG for wind turbine applications.

Toward an Optimum Design of Large-Scale HTS Synchronous Generator for Wind Turbine Applications

In this paper, a thorough analysis is carried out to obtain an optimum design for a 10-MW-class high-temperature superconducting (HTS) synchronous generator for wind conversion systems. Different design challenges are studied, and a multiobjective function, which includes mass, cost, volume, and operating characteristics of the generator, has been considered. An improved analytical hierarchy process technique as a multiobjective decision-making algorithm is used to optimize the proposed objective function, and thereby, optimum dimension parameters of the generator are achieved. It is deduced that the generator total cost, particularly the HTS material price, has considerable influence on the optimum structure of the generator, which should be considered in the design procedure. This investigation suggested a precise study to obtain an optimum structure of the large-scale HTS synchronous generator for wind turbine applications.

An AHP-based approach for design optimization of flux-switching permanent magnet generator for wind turbine applications

Summary Compared with different types of renewable energies, wind energy has the fastest annual growing rate over the last decade. Hence, employing a framework based on numerical algorithms for optimal design of electrical generator, especially adopted for wind power systems, is a great challenge in electrical systems. Recently, for their rigid structure, high torque density and lower mass of the flux-switching permanent magnet (FSPM) generators have attracted much interest because they are capable of supplementing conventional permanent magnet synchronous generators. In this paper, a new analytical hierarchy process (AHP) approach is proposed for a multi-objective optimization of the design of the FSPM generator. To carry out the optimization, trade-offs are considered among more conflicting targets (cost, mass, and some electromagnetic performance). Finite element method numerical results, experimentally validated by means of a prototype, have been used to assess the required data for the optimization. Then the optimal solutions given by the AHP method have been compared with the solutions obtained using different classical optimization methods. The results showed that the AHP approach gives the best solution with respect to the earlier designs and also with respect to other conventional optimization methods, confirming its effectiveness to be used in the optimal design of electrical machines. Copyright © 2015 John Wiley & Sons, Ltd.

Grid Connected based PWM Converter Applied a Self-excited Induction Generator for Wind Turbine Applications

This paper presents the electrical power conversion system which is developed for a self-excited induction generator in order to apply with wind turbine. In the wind energy conversion system, a self-excited induction generator is converted the mechanical energy into electrical energy. A B6 rectifier and capacitor are utilized to maintain constant intermediate DC voltage. The average power is converted entirely by the PWM converter, consists of B6 voltage-source inverters. Output currents and active power of switch mode voltage source inverter are flowed into utility grid by current control and PQ theory technique. For the hardware implementation, the system consists of 1kW four poles self excited induction generator and the voltage source inverter controlled output current by hysteresis controller(bang-bang) method. The algorithm is implemented in a dSPACS ds1104DSP together with MATLAB/SIMULINK program. The validity of the proposed method is verified by both simulation and experimental results under power transferred into grid in term of power quality such as real power, reactive power, total harmonics distortion, and so on.

A multiple observers and dynamic weighting ensembles scheme for diagnosing new class faults in wind turbines

This paper presents an incremental way to design the decision module of a diagnostic system by resorting to dynamic weighting ensembles of classifiers. The method is applied for sensor fault detection and isolation in a doubly fed induction generator for wind turbine application. Three sets of observers are combined to generate residuals that are robust to operating point changes. These signals are progressively fed into a dynamic weighting ensembles algorithm, called Learn++.NC, for fault classification. The algorithm incrementally learns the residuals–faults relationships and dynamically classifies the faults including multiple new classes. It resorts to a dynamically weighted consult and vote mechanism to combine the outputs of the base-classifiers.

Grid Connected Based Six-Pulse Converter Applied A Self-Excited Induction Generator for Wind Turbine Applications

Abstract This paper the electrical power conversion system presents developed for a self-excited induction generator for wind turbine applications. In the wind energy conversion system a self-excited induction generator converts the mechanical energy into electrical energy. A B6 rectifier and inductor are utilized to maintain constant dc link current. The average power is converted entirely by the six-pulse converter, it's consists of a B6 current-source inverters. Line side current-source inverter supply currents into the utility line by regulating the dc link voltage. The active power is controlled by firing angle of converter with operated at inverter mode. The performance improvement of this proposed system by experiment using a 1 kW four pole self excited induction generator. The overall control system is implemented on six-pulse converter board. Experimental results are illustrated in order to validate performance of the proposed system.

A compact, high efficiency contra-rotating generator suitable for wind turbines in the urban environment

This paper is concerned with the design, development and performance testing of a permanent magnet (PM) generator for wind turbine applications in urban areas. The radially interacting armature windings and magnet array are carried on direct drive, contra-rotating rotors, resulting in a high torque density and efficiency. This topology also provides improved physical and mechanical characteristics such as compactness, low starting torque, elimination of gearboxes, low maintenance, low noise and vibration, and the potential for modular construction. The design brief required a 50 kW continuous rated prototype generator, with a relative speed at the air-gap of 500 rpm. A test rig has been instrumented to give measurements of the mechanical input (torque and speed) and electrical output (voltage, current and power) of the generator, as well as temperature readings from inside the generator using a wireless telemetry device. Peak power output was found to be 48 kW at a contra-rotating speed of 500 rpm, close to the design target, with an efficiency of 94%. It is anticipated that the generator will find application in a wide range of wind turbine designs suited to the urban environment, e.g. types sited on the top of buildings, as there is growing interest in providing quiet, low cost, clean electricity at point of use.

Neural network controller based induction generator for wind turbine applications

Neural network controller based induction generator for wind turbine applications

Current waveform distortion of doubly‐fed generator for wind turbine application by spatial higher harmonics

AbstractThis paper describes a method to analyze higher harmonic currents resulting from higher space harmonics, depending on the winding pattern of a doubly‐fed generator. A 1.5‐MW generator was used for the analysis, and the results are compared using finite element magnetic field analysis and measurements.The result revealed that the proposed analysis, which focuses on the winding pattern and takes into account higher space harmonics, allows us to calculate higher harmonic currents at high precision, understand the mechanism of changing higher harmonic currents due to the slip or the load of the generator and considerably reduce higher harmonic currents at the armature by restricting higher harmonic currents at the magnetic field. In addition, the sensitivity analysis of design parameters clarified the relationship between current distortion and basic characteristics on electric designs. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(2): 79–85, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20606

風力用交流励磁形同期発電機における空間高調波による電流波形歪みの解析と考察

風力用交流励磁形同期発電機における空間高調波による電流波形歪みの解析と考察