Adaptive robust speed control for continuously variable transmission in wind turbine under grid faults

2018 ◽  
Vol 10 (6) ◽  
pp. 063302 ◽  
Author(s):  
Xin Wu ◽  
Runhe Tian ◽  
Xiaoming Rui
Keyword(s):  
Wind Turbine ◽  
Speed Control ◽  
Continuously Variable Transmission ◽  
Variable Transmission

Improvement of fuel economy by shift speed control for a metal belt continuously variable transmission

2002 ◽  
Vol 216 (9) ◽  
pp. 741-749 ◽  
Author(s):  
H Lee ◽  
H Kim
Keyword(s):  
Fuel Economy ◽  
Dynamic Models ◽  
Control Valve ◽  
Speed Control ◽  
Pressure Control ◽  
Continuously Variable Transmission ◽  
Hydraulic Loss ◽  
Variable Transmission ◽  
Line Pressure ◽  
Shift Speed

In this paper, an algorithm to improve the fuel economy of a metal belt continuously variable transmission (CVT) vehicle by CVT shift speed control is suggested. By rearranging the CVT shift dynamic equation, it is found that the CVT shift speed depends on the line pressure as well as on the primary pressure. CVT shift speed maps are constructed to evaluate the influence of the line pressure on the shift speed. To obtain a target shift speed, an algorithm to calculate the line pressure is presented. In order to estimate the shift speed and the hydraulic loss, dynamic models of the line pressure control valve and the ratio control valve are obtained by considering the CVT shift dynamics and validated by experiments. It is found from the simulation results that fuel economy can be improved by 2 per cent in spite of the increased hydraulic loss due to the increased line pressure.

Increasing the regulating ability of a wind turbine in a local power system using magnetic continuous variable transmission

2018 ◽  
Vol 42 (5) ◽  
pp. 411-435 ◽  
Author(s):  
Sergey N Udalov ◽  
Andrey A Achitaev ◽  
Alexander G Pristup ◽  
Boris M Bochenkov ◽  
Yuri Pankratz ◽  
...  
Keyword(s):  
Power Systems ◽  
Power System ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Continuously Variable Transmission ◽  
Local Power ◽  
Diesel Generator ◽  
Gas Turbine Unit ◽  
Variable Transmission ◽  
Autonomous Power System

The paper is devoted to investigations of dynamic processes in a local power system consisting of wind turbines with a magnetic continuously variable transmission. Due to low inertia of wind turbine generator rotors, there is a problem of ensuring dynamic stability at sharp load changes or at short circuits in an autonomous power system. To increase dynamic stability of the system, two algorithms for controlling a magnetic continuously variable transmission are presented. The first algorithm stabilizes a rotation speed of the high-speed rotor of a magnetic continuously variable transmission from the generator side in a local power system consisting of wind turbines with uniform synchronous generators with permanent magnets having equal moments of inertia. Undoubtedly, local power systems having only the wind turbines with equal mechanical inertia time constants are not widely used due to stochastic nature of wind energy. Therefore, wind power systems are combined with a diesel generator or a gas-turbine unit. Investigations show that the use of the only speed stabilization algorithm is not enough for such power systems, because there is a possibility for occurrence of asynchronous operation under specific power changes due to the difference in moments of inertia of generator rotors. Thus, the second algorithm uses the phase shift compensation in accordance with a primary generator in an autonomous power system consisting of non-uniform generators having different mechanical inertia time constants. As a primary generator, a diesel generator or a gas-turbine unit having a primary speed controller may be used. It should be noted that algorithms of stabilization for speed and phase angle are extended by an inertial circuit of aerodynamic compensation for torque of rotation from the wind turbine side to reduce loading on an energy storage unit of the magnetic continuously variable transmission at disturbances from the generator side and the turbine side.

Methods for Controlling a Wind Turbine System With a Continuously Variable Transmission in Region 2

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Andrew H. Rex ◽  
Kathryn E. Johnson
Keyword(s):  
Wind Turbine ◽  
Gear Ratio ◽  
Continuously Variable Transmission ◽  
Variable Speed ◽  
Wind Turbine System ◽  
Variable Speed Wind Turbine ◽  
Fast Wind ◽  
Variable Transmission ◽  
Integral Controller ◽  
Proportional Integral Controller

Variable speed operation enables wind turbine systems to increase their aerodynamic efficiency and reduce fatigue loads. An alternative to the current electrically based variable speed technologies is the continuously variable transmission (CVT). A CVT is a transmission whose gear ratio can be adjusted to take on an infinite number of settings within the range between its upper and lower limits. CVT research in wind turbine applications predicts an improvement in output power and torque loads compared with fixed-speed machines. Also, a reduction in the harmonic content of the currents is anticipated by eliminating the power electronics. This paper develops a model that combines a CVT model with the FAST wind turbine simulator for simulating the system’s performance in MATLAB/SIMULINK. This model is useful for control development for a variable-speed wind turbine using a CVT. The wind turbine with CVT is simulated using two controllers: a proportional-integral controller and a nonlinear torque controller of the type commonly used in the wind industry.

The Shift Speed Control of CVT on Different Conditions

2013 ◽  
Vol 373-375 ◽  
pp. 104-107
Author(s):  
Jing Jing Xia
Keyword(s):  
Speed Control ◽  
Continuously Variable Transmission ◽  
Transmission System ◽  
Dynamics Analysis ◽  
Change Rate ◽  
Variable Transmission ◽  
Ratio Change ◽  
Shift Speed

It will cause the drop of the acceleration performance and driving comfort if the continuously variable transmission shift too quickly. So Aiming at the shifting problem of continuously variable transmission system, This thesis put forward the method to control shift speed of the continuously variable transmission based on driving intention. By the dynamics analysis of continuously variable transmission system, it does a research on the influence on the motor automobiles acceleration performance and driving comfort, when the ratio changes too fast. According to working practice, analyzing shift way of continuously variable transmission system. Through the above analysis and findings, the method to control shift speed based on driving intention will be designed to make acceleration and driving comfort unified. And by limiting the maximum CVT ratio change rate, the automobile acceleration performance can be further improved.

Sign in / Sign up

Export Citation Format

Share Document