Design and Optimization of Electric Continuous Variable Transmission System for Wind Power Generation

This paper introduces modeling of a gearless hydraulic transmission system that provides an infinite speed ratio like continuous variable transmission (CVT). The transmission system is modeled in various operating conditions such as all-electric and gasoline configurations. The results demonstrate the high performance operation of the transmission system.

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Gear Based Quasi-Continuous Variable Transmission for Wind Turbines

Volume 6B: Energy ◽

10.1115/imece2015-50683 ◽

2015 ◽

Author(s):

Krista Hernandez ◽

Dania Wilson ◽

Kyle Ressel ◽

Justus Nwoke ◽

Martin Soto ◽

...

Keyword(s):

Wind Turbine ◽

Wind Turbines ◽

Continuous Variable ◽

Transmission System ◽

Constant Speed ◽

Spur Gears ◽

Variable Speed ◽

Electrical Load ◽

Continuous Variable Transmission ◽

Variable Transmission

Over the past decade wind turbines have been proven to be a competitive contender to produce cheap electricity. Their output electrical power went from few dozens of watts to several megawatts, and this trend is continuing to increase as they become larger in size. Most of these wind turbines are typically regulated through a set of controls acting on the electricity generator workload. These controls are achieved through the use of power electronics controlling the electrical load on the generator for variable speed wind turbine. This paper explores the possibility of implementing an alternative control system in variable wind speed turbines using a special gearbox with a high number of close consecutive discrete gear ratios. The proposed gear based Quasi-Continuous Variable Transmission, called QCVT, allows a variable speed at the input shaft and delivers a quasi-constant speed at the output shaft of the gearbox. The system consists of a special drivetrain assembly of spur gears run and controlled automatically through a set of clutch power shifters. The clutches are used to shift a set of compound gears, thus modifying the drivetrain total gear ratio. The designed system can produce up to 625 gear ratios and acts as a quasi-continuously variable transmission between the wind turbine hub and the electricity generator which requires a constant entry speed delivering a frequency of 60 Hz. The gearing transmission system has been designed using the SolidWorks CAD software for modeling and simulation and the gearing design theory has been used to dimension the special drivetrain assembly of spur gears. The kinematic gearing theory has been used to establish the multitude of close consecutive discrete gearing ratios of the transmission system. A wind driven rotor model for the wind turbine power coefficient has been used to determine the power absorbed by the wind turbine from the blowing wind and the power delivered to the electricity generator. The wind turbine torque generated by the wind and the torque produced at the electricity generator have also been determined using the multitude of gear ratios of the designed drivetrain. A new control law is established to keep the wind turbine generator running at a quasi-constant speed while producing maximum power. Considering the QCVT with its numerous close and consecutive gear ratios as the main torque regulator, the wind turbine system is expected to deliver the right needed torque for a specified electrical load. A set of results featuring how the electricity generator power and torque can be controlled by shifting the ratios of drivetrain transmissions are delivered. A particular emphasis is put on maximizing the generator delivered power using controlled gear ratios while the speed of the wind is changing. A small scale prototype of the QCVT powertrain transmission has been designed and built for concept demonstration and testing purposes.

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Development of a Novel Brushless Power Split Transmission System for Wind Power Generation Application

IEEE Transactions on Magnetics ◽

10.1109/tmag.2014.2331075 ◽

2014 ◽

Vol 50 (11) ◽

pp. 1-4 ◽

Cited By ~ 7

Author(s):

Shuangxia Niu ◽

Yulong Liu ◽

S. L. Ho ◽

W. N. Fu

Keyword(s):

Power Generation ◽

Wind Power ◽

Transmission System ◽

Wind Power Generation ◽

Power Split

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Gearless Continuously Variable Transmission Technology and its Application in Wind Power Generation

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.614.145 ◽

2014 ◽

Vol 614 ◽

pp. 145-150

Author(s):

Jin Gui Qian ◽

Si Jia Zhou ◽

Ji Bao Huang ◽

Ke Gang Zhao

Keyword(s):

Power Generation ◽

Wind Power ◽

Engineering Application ◽

Continuously Variable Transmission ◽

Wind Power Generation ◽

Direct Drive ◽

Generation System ◽

Constant Frequency ◽

Variable Transmission ◽

Power Generation System

Based on gearless continuously variable transmission technology, a cascaded wind power generation system with Variable Speed Constant Frequency (VSCF) is presented in this paper. The system has combined the advantages of doubly-fed and direct-drive wind power generation system. The raising-speed gear box has been done away with, and the system reliability has been improved. Reducing the power capacity of the aspects of the variable frequency speed regulation, the function of grid-connected electricity generation can be achieved with less cost. Synchronous generator directly connects to grid, which helps to optimize power quality. The topological structure of system is discussed in this paper, and its operating principle is analyzed, revealing its characteristics and engineering application prospects.

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On the efficiency of a prototype continuous variable transmission system

21st Mediterranean Conference on Control and Automation ◽

10.1109/med.2013.6608736 ◽

2013 ◽

Cited By ~ 4

Author(s):

P. Spanoudakis ◽

N. C. Tsourveloudis

Keyword(s):

Continuous Variable ◽

Transmission System ◽

Continuous Variable Transmission ◽

Variable Transmission

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Continuous Variable Transmission With an Inertia-Regulating System

Journal of Mechanical Design ◽

10.1115/1.4001378 ◽

2010 ◽

Vol 132 (5) ◽

Cited By ~ 5

Author(s):

G. Centeno ◽

F. Morales ◽

F. B. Perez ◽

F. G. Benitez

Keyword(s):

Angular Velocity ◽

Power Transmission ◽

Continuous Variable ◽

Transmission System ◽

Computational Simulations ◽

Efficient Manner ◽

Additional Degree ◽

System A ◽

Continuous Variable Transmission ◽

Variable Transmission

This article describes a power transmission system applicable to vehicles. It consists of an oscillating, ratcheting-type, continuously variable transmission (CVT) system governed by an inertia mechanism. The inertia-regulating mechanism adds an additional degree of freedom and gives the system a dynamic character. The transmission consists of three different subsystems. The first of these converts the rotation of the engine or motor into an oscillating angular velocity movement and regulates the amplitude of this movement. The oscillating rotation from the first subsystem is used to drive a second subsystem, which acts as a regulating device by means of an inertial mechanism. The oscillating movement at the output of the second subsystem is rectified in the third, resulting in a unidirectional angular velocity. As a result, a unidirectional torque is generated at the output of the CVT, commensurate with the operating condition of the transmission, and this is capable of overcoming a torque resistance. A prototype of this transmission was built and tested to check the experimental results against those predicted by a series of computational simulations. As a result, the experimental graphs that characterize the operation of this type of transmission system were obtained, demonstrating its ability to function in an efficient manner.

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