Control system stability

AccessScience ◽  
2015 ◽  
2014 ◽  
Vol 977 ◽  
pp. 334-337
Author(s):  
Xi Lei ◽  
Gui Zhi Xu ◽  
Ke Zheng Xing

As a flexible AC transmission system equipment, controlled shunt reactor is becoming increasingly important in the grid with the development of EHV / UHV transmission systems. Since currently rated voltage of controlled shunt reactor has developed to 1100kV, as its capacity control system, or valve-control system, stability and reliability test is very important. In this paper, the test circuit and method for the valve-control system in the laboratory or the test station for combined adjustment test is put forward. By adjustment of power supply and the device parameter, the valve-control system can put the voltage and current of the device to be the same as the on-set operation. Actual test of the world's first 1100kV controlled shunt reactor valve-control system shows that, the test method in this paper is correct and feasible, and the objective of assessment can be achieved.


2004 ◽  
Vol 124 (5) ◽  
pp. 697-704
Author(s):  
Suresh Chand Verma ◽  
Shigeaki Ogawa ◽  
Shinya Noguchi ◽  
Masaru Shimomura

2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Afif Caesar Distara ◽  
Fatkhur Rohman

Electric vehicles are alternative vehicles that carry energy efficient. At this time the dominant vehicle uses ordinary wheels so that it will become an obstacle in the maneuver function that requires movement in various directions. With mechanum wheels the vehicle can move in various directions by adjusting the direction of rotation of each wheel. The problem is choosing the right control system for the control system needed by the vehicle. The purpose of this study is to determine and analyze the effect of variations in the value of PI (Proportional Integral) and speed of the vehicle to the stability response of the system to control the direction of prototype electric vehicles. This study method is an experiment that is by giving a treatment, then evaluating the effects caused by the research object. The results of this study can be concluded that the variation of PI constant values and speed variations have an effect on the stability parameters of the system, namely rise time, settling time, overshot, and steady state error. To get the best system stability response results can use the constant value PI Kp = 2; and Ki = 17; where the stability response of the system for direction control at each speed condition has a fairly good value with a fast rise time, fast settling time, small overshot and a small error steady state compared to other PI constant values in this study.Keywords: mechanum wheel, PI control, direction, prototype, system stability


Author(s):  
Thomas E. Russell ◽  
Crystal Heshmat ◽  
Dennis Locke

A novel, high-speed, high temperature, oil-free, foil thrust bearing test rig has been developed with a critical element being a double-acting, active magnetic thrust bearing. The magnetic thrust bearing is used to react against loads applied to the foil thrust bearing under test. The magnetic bearing has the capability of reacting against thrust loads of up to 2224 N (500 pounds) at speeds to 80,000 rpm, while the rotor is supported by foil journal bearings. Two issues that are especially challenging for this test rig are magnetic material selection and the electronic control system. The magnetic material selection is critical due to the high centrifugal stresses that occur at 80,000 rpm. The electronic control system must handle the non-linear variation in stiffness and damping that is seen by the magnetic thrust bearing as the foil thrust bearing is loaded, as well as maintain rotor system stability as the foil bearing is purposefully overloaded to the point of failure to discover maximum load and performance capabilities. This paper describes the design of the active magnetic thrust bearing, the material selection process, and the development of a digital signal processor based control system. Typical experimental data obtained during operation of the test rig will also be presented.


2017 ◽  
Author(s):  
Andrey A. Kapelyuhovskiy ◽  
Alexandra A. Kapelyuhovskaya ◽  
Elena P. Stepanova

2012 ◽  
Vol 463-464 ◽  
pp. 1663-1667
Author(s):  
Hai Na Hu ◽  
Wu Wang

Automatic Voltage Regulator (AVR) was applied to hold terminal voltage magnitude of a synchronous generator at a specified level and its stability seriously affects the security of power system. PID control was applied for AVR system control, but the parameters of PID controller were hard to determine, to overcome this problem, some intelligent techniques should be taken. Wavelet Neural Network (WNN) was constrictive and fluctuant of wavelet transform and has self-study, self adjustment and nonlinear mapping functions of neural networks, so the structure of WNN and PID tuning with WNN was proposed, the tuning algorithm was applied into AVR control system, the simulation was taken with normal BP neural network and WNN, the efficiency and advantages of this control strategy was successfully demonstrated which can applied into AVR system for power system stability.


Author(s):  
Yuan Yao ◽  
Yapeng Yan ◽  
Zhike Hu ◽  
Kang Chen

We put forward the motor active flexible suspension and investigate its dynamic effects on the high-speed train bogie. The linear and nonlinear hunting stability are analyzed using a simplified eight degrees-of-freedom bogie dynamics with partial state feedback control. The active control can improve the function of dynamic vibration absorber of the motor flexible suspension in a wide frequency range, thus increasing the hunting stability of the bogie at high speed. Three different feedback state configurations are compared and the corresponding optimal motor suspension parameters are analyzed with the multi-objective optimal method. In addition, the existence of the time delay in the control system and its impact on the bogie hunting stability are also investigated. The results show that the three control cases can effectively improve the system stability, and the optimal motor suspension parameters in different cases are different. The direct state feedback control can reduce corresponding feed state's vibration amplitude. Suppressing the frame's vibration can significantly improve the running stability of bogie. However, suppressing the motor's displacement and velocity feedback are equivalent to increasing the motor lateral natural vibration frequency and damping, separately. The time delay over 10 ms in control system reduces significantly the system stability. At last, the effect of preset value for getting control gains on the system linear and nonlinear critical speed is studied.


1968 ◽  
Vol 115 (12) ◽  
pp. 1828 ◽  
Author(s):  
J.P. Norton ◽  
B.J. Cory

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