scholarly journals Power-Split Hydrostatic Transmissions for Wind Energy Systems

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3369 ◽  
Author(s):  
Francesco Bottiglione ◽  
Giacomo Mantriota ◽  
Marco Valle

In a wind turbine, if a continuously variable transmission is placed between the turbine rotor and the generator, the speed ratio can be tuned to match the variable rotor speed to the constant speed of the electric generator, thus eliminating the need to adapt the frequency to the grid. In this paper, power-split hydrostatic transmission (PS-HTS) architecture is proposed as a suitable continuously variable transmission for application to wind turbine systems. The performance of PS-HTS is modelled and compared with that of previously proposed architectures in which the hydrostatic transmission is placed in-line with traditional drives (in-line HTS). It is shown here that the PS-HTS can improve the annual energy production of a 250 kW rated power wind turbine of about 10–11% by employing a hydrostatic transmission with one-seventh the size of the one requested by in-line HTS architecture.

Energies ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 376
Author(s):  
Biswaranjan Mohanty ◽  
Kim A. Stelson

Hydrostatic transmissions are commonly used in heavy-duty equipment for their design flexibility and superior power density. Compared to a conventional wind turbine transmission, a hydrostatic transmission (HST) is a lighter, more reliable, cheaper, continuously variable alternative for a wind turbine. In this paper, for the first time, a validated dynamical model and controlled experiment have been used to analyze the performance of a hydrostatic transmission with a fixed-displacement pump and a variable-displacement motor for community wind turbines. From the dynamics of the HST, a pressure control strategy is designed to maximize the power capture. A hardware-in-the-loop simulation is developed to experimentally validate the performance and efficiency of the HST drive train control in a 60 kW virtual wind turbine environment. The HST turbine is extensively evaluated under steady and time-varying wind on a state-of-the-art power regenerative hydrostatic dynamometer. The proposed controller tracks the optimal tip-speed ratio to maximize power capture.


Author(s):  
Paul Schünemann ◽  
Timo Zwisele ◽  
Frank Adam ◽  
Uwe Ritschel

Floating wind turbine systems will play an important role for a sustainable energy supply in the future. The dynamic behavior of such systems is governed by strong couplings of aerodynamic, structural mechanic and hydrodynamic effects. To examine these effects scaled tank tests are an inevitable part of the design process of floating wind turbine systems. Normally Froude scaling is used in tank tests. However, using Froude scaling also for the wind turbine rotor will lead to wrong aerodynamic loads compared to the full-scale turbine. Therefore the paper provides a detailed description of designing a modified scaled rotor blade mitigating this problem. Thereby a focus is set on preserving the tip speed ratio of the full scale turbine, keeping the thrust force behavior of the full scale rotor also in model scale and additionally maintaining the power coefficient between full scale and model scale. This is achieved by completely redesigning the original blade using a different airfoil. All steps of this redesign process are explained using the example of the generic DOWEC 6MW wind turbine. Calculations of aerodynamic coefficients are done with the software tools XFoil and AirfoilPrep and the resulting thrust and power coefficients are obtained by running several simulations with the software AeroDyn.


2020 ◽  
Vol 1 (4) ◽  
pp. 25-37
Author(s):  
A.E. Yesakov ◽  
◽  
A.V. Kretov ◽  
P.A. Krasavin ◽  
◽  
...  

Variators of different operating principles and designs are of interest as components of automatic transmissions for ground transport and traction machines. At the same time, one of the most popular types of variators are the variators built on the basis of continuously variable transmissions with flexible links. The main reasons for the use of such variators in the transmissions of a number of modern passenger vehicles are, on the one hand, the emergence of flexible link designs with high durability, and, on the other hand, the widespread introduction of programmable electronic devices into automatic control systems for continuously variable transmissions. A direct consequence of the latter circumstance was the need for in-depth research aimed at synthesizing such control algorithms that would make it possible to fully use the advantages inherent in continuously variable transmissions with flexible links and minimize the operational consequences of their shortcomings. This paper makes an attempt to solve the problem of synthesizing the algorithm in a preliminary form, based on the goal of providing the vehicle with the best traction and speed properties. The presence of such an attempt will allow, having set the main parameters of a continuously variable transmission for some reason, to develop the hardware of the automatic control system. In turn, this will make it possible to synthesize a refined algorithm that takes into account the dynamics of the system, errors of meters and signal conversion devices, as well as other factors affecting work pro-cesses. When considering the described problem, various variants of the geometry of the contact surfaces of the continuously variable transmission links were taken into account and the corre-sponding mathematical apparatus were formed. The results of calculations, obtained by computer program that implements these devices, are selectively presented in the materials of the paper.


Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2578 ◽  
Author(s):  
Krishnamoorthi Sivalingam ◽  
Steven Martin ◽  
Abdulqadir Singapore Wala

Aerodynamic performance of a floating offshore wind turbine (FOWT) is significantly influenced by platform surging motions. Accurate prediction of the unsteady aerodynamic loads is imperative for determining the fatigue life, ultimate loads on key components such as FOWT rotor blades, gearbox and power converter. The current study examines the predictions of numerical codes by comparing with unsteady experimental results of a scaled floating wind turbine rotor. The influence of platform surge amplitude together with the tip speed ratio on the unsteady aerodynamic loading has been simulated through unsteady CFD. It is shown that the unsteady aerodynamic loads of FOWT are highly sensitive to the changes in frequency and amplitude of the platform motion. Also, the surging motion significantly influences the windmill operating state due to strong flow interaction between the rotating blades and generated blade-tip vortices. Almost in all frequencies and amplitudes, CFD, LR-BEM and LR-uBEM predictions of mean thrust shows a good correlation with experimental results.


Energy ◽  
2014 ◽  
Vol 67 ◽  
pp. 623-630 ◽  
Author(s):  
Shahaboddin Shamshirband ◽  
Dalibor Petković ◽  
Amineh Amini ◽  
Nor Badrul Anuar ◽  
Vlastimir Nikolić ◽  
...  

2019 ◽  
Vol 9 (10) ◽  
pp. 2074 ◽  
Author(s):  
Hangyang Li ◽  
Yunshan Zhou ◽  
Huanjian Xiong ◽  
Bing Fu ◽  
Zhiliang Huang

The energy management strategy has a great influence on the fuel economy of hybrid electric vehicles, and the equivalent consumption minimization strategy (ECMS) has proved to be a useful tool for the real-time optimal control of Hybrid Electric Vehicles (HEVs). However, the adaptation of the equivalent factor poses a major challenge in order to obtain optimal fuel consumption as well as robustness to varying driving cycles. In this paper, an adaptive-ECMS based on driving pattern recognition (DPR) is established for hybrid electric vehicles with continuously variable transmission. The learning vector quantization (LVQ) neural network model was adopted for the on-line DPR algorithm. The influence of the battery state of charge (SOC) on the optimal equivalent factor was studied under different driving patterns. On this basis, a method of adaptation of the equivalent factor was proposed by considering the type of driving pattern and the battery SOC. Besides that, in order to enhance drivability, penalty terms were introduced to constrain frequent engine on/off events and large variations of the continuously variable transmission (CVT) speed ratio. Simulation results showed that the proposed method efficiently improved the equivalent fuel consumption with charge-sustaining operations and also took into account driving comfort.


2011 ◽  
Vol 291-294 ◽  
pp. 2861-2865 ◽  
Author(s):  
Qiang Jiang ◽  
Hong Yi Liu ◽  
Jian Jun Hao ◽  
Yue Cheng

Electromechanical control CVT (EM-CVT) is a new type of continuously variable transmission, and its ratio quality is an important parameter validated the performance of vehicle. In order to study the dynamical coupling technology between EM-CVT and engine under the running state of vehicle, the special character of two working models is obtained by engine experiment; according to the principle of the EM-CVT, the relation between vehicle speed and ration is theoretically analyzed. Based on the basic theory of PID control, the improved PID control algorithm is proposed for the speed ratio control of the EM-CVT, and experimental verification is made. The experimental results show that there is a significant effect on the system with this algorithm.


2012 ◽  
Vol 229-231 ◽  
pp. 2323-2326
Author(s):  
Zong Qi Tan ◽  
Can Can Li ◽  
Hui Jun Ye ◽  
Yu Qiong Zhou ◽  
Hua Ling Zhu

This paper designed the controller of the wind turbine rotor rotating speed. This model of adaptive-PID through control the tip-speed ratio and count the values of PID for variable wind speed. From the result of simulation, the wind speed can run in a good dynamic characteristic, and keep the rotor running in the best tip-speed ratio at the same time.


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