scholarly journals A Novel Piecewise Frequency Control Strategy Based on Fractional-Order Filter for Coordinating Vibration Isolation and Positioning of Supporting System

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5307
Author(s):  
Yeying Tao ◽  
Wei Jiang ◽  
Bin Han ◽  
Xiaoqing Li ◽  
Ying Luo ◽  
...  
Keyword(s):  
Fractional Order ◽  
Control Strategy ◽  
Vibration Isolation ◽  
Frequency Control ◽  
Low Frequency ◽  
Stability Margin ◽  
System Stability ◽  
Supporting System ◽  
Frequency Position ◽  
The Stability

A piecewise frequency control (PFC) strategy is proposed in this paper for coordinating vibration isolation and positioning of supporting systems under complex disturbance conditions, such as direct and external disturbances. This control strategy is applied in an active-passive parallel supporting system, where relative positioning feedback for positioning and absolute velocity feedback for active vibration isolation. The analysis of vibration and deformation transmissibility shows that vibration control increases low-frequency position error while positioning control amplifies high-frequency vibration amplitude. To overcome this contradiction across the whole control bandwidth, a pair of Fractional-Order Filters (FOFs) is adopted in the PFC system, which increases the flexibility in the PFC design by introducing fraction orders. The system stability analysis indicates that the FOFs can provide a better stability margin than the Integral-Order Filters (IOFs), so the control gains are increased to get a better performance on the AVI and positioning. The PFC based on FOFs can suppress the peak amplitude at the natural frequency which cannot be avoided when using the IOFs. The constrained nonlinear multivariable function is formed by the required performance and the stability of the system, then the controller parameters are optimized effectively. Lastly, the effectiveness of the proposed method is verified by experiments.

scholarly journals Optimal Location and Design of TCSC controller For Improvement of Stability

2011 ◽  
pp. 210-215
Author(s):  
Swathi Kommamuri ◽  
P. Sureshbabu
Keyword(s):  
Power System ◽  
Optimization Problem ◽  
Low Frequency ◽  
System Stability ◽  
Simulation Environment ◽  
Swarm Optimization ◽  
Stability Performance ◽  
Low Frequency Oscillations ◽  
Simulation Results ◽  
The Stability

Power system stability improvement by a coordinate Design ofThyristor Controlled Series Compensator (TCSC) controller is addressed in this paper.Particle Swarm Optimization (PSO) technique is employed for optimization of the parameterconstrained nonlinear optimization problem implemented in a simulation environment. The proposed controllers are tested on a weakly connected power system. The non-linear simulation results are presented. The eigenvalue analysis and simulation results show the effectiveness and robustness of proposed controllers to improve the stability performance of power system by efficient damping of low frequency oscillations under various disturbances.

Frequency-domain analysis method for analyzing and improving the steady-state characteristics of microcantilever in tapping-mode atomic force microscopy

2018 ◽  
Vol 82 (1) ◽  
pp. 10701
Author(s):  
Xiaohui Gu ◽  
Lining Sun ◽  
Changhai Ru
Keyword(s):  
Steady State ◽  
Frequency Domain ◽  
Stability Margin ◽  
Domain Analysis ◽  
Frequency Domain Analysis ◽  
System Stability ◽  
Analysis Method ◽  
External Interference ◽  
Tapping Mode ◽  
The Stability

In tapping-mode AFM, the steady-state characteristics of microcantilever are extremely important to determine the AFM performance. Due to the external excitation signal and the tip-sample interactions, the solving process of microcantilever motion equation will become very complicated with the traditional time-domain analysis method. In this paper, we propose the novel frequency-domain analysis method to analyze and improve the steady-state characteristics of microcantilever. Compared with the previous methods, this new method has three prominent advantages. Firstly, the analytical expressions of amplitude and phase of cantilever system can be derived conveniently. Secondly, the stability of the cantilever system can be accurately determined and the stability margin can be obtained quantitatively in terms of the phase margin and the magnitude margin. Thirdly, on this basis, external control mechanism can be devised quickly and easily to guarantee the high stability of the cantilever system. With this novel method, we derive the frequency response curves and discuss the great influence of the intrinsic parameters on the system stability, which provides theoretical guidance for selecting samples to achieve better AFM images in the experiments. Moreover, we introduce a new external series correction method to significantly increase the stability margin. The results indicate that the cantilever system is no longer easily disturbed by external interference signals.

scholarly journals Robust LFC Strategy for Wind Integrated Time-Delay Power System Using EID Compensation

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3223 ◽  
Author(s):  
Liu ◽  
Zhang ◽  
Zou
Keyword(s):  
Time Delay ◽  
Power System ◽  
Closed Loop ◽  
Frequency Control ◽  
Loop System ◽  
Load Frequency Control ◽  
System Stability ◽  
Linear Matrix ◽  
Closed Loop System ◽  
The Stability

This paper presents an active disturbance rejection control (ADRC) technique for load frequency control of a wind integrated power system when communication delays are considered. To improve the stability of frequency control, equivalent input disturbances (EID) compensation is used to eliminate the influence of the load variation. In wind integrated power systems, two area controllers are designed to guarantee the stability of the overall closed-loop system. First, a simplified frequency response model of the wind integrated time-delay power system was established. Then the state-space model of the closed-loop system was built by employing state observers. The system stability conditions and controller parameters can be solved by some linear matrix inequalities (LMIs) forms. Finally, the case studies were tested using MATLAB/SIMULINK software and the simulation results show its robustness and effectiveness to maintain power-system stability.

Anti-Synchronization Control of the Complex Lu System

2014 ◽  
Vol 721 ◽  
pp. 269-272
Author(s):  
Fan Di Zhang
Keyword(s):  
Complex System ◽  
Fractional Order ◽  
Control Strategy ◽  
Stability Theorem ◽  
Projective Synchronization ◽  
Synchronization Control ◽  
Fractional Order Systems ◽  
Lü System ◽  
The Stability ◽  
Lu System

This paper propose fractional-order Lu complex system. Moreover, projective synchronization control of the fractional-order hyper-chaotic complex Lu system is studied based on feedback technique and the stability theorem of fractional-order systems, the scheme of anti-synchronization for the fractional-order hyper-chaotic complex Lu system is presented. Numerical simulations on examples are presented to show the effectiveness of the proposed control strategy.

Low frequency control strategy for seismic attenuators with inertial monolithic mechanical sensors

2017 ◽  
Author(s):  
F. Barone ◽  
G. Giordano ◽  
R. De Rosa ◽  
F. Acernese ◽  
R. Romano
Keyword(s):  
Control Strategy ◽  
Frequency Control ◽  
Low Frequency ◽  
Mechanical Sensors

scholarly journals Enhancement of Power System Transient Stability By Fractional Order Controlled STATCOM Tuned By PSO

2018 ◽  
Vol 7 (4.24) ◽  
pp. 163
Author(s):  
R.S. Srinivas ◽  
P.V.Ramana Rao
Keyword(s):  
Power System ◽  
Fractional Order ◽  
Transient Stability ◽  
Stability Margin ◽  
Computational Effort ◽  
Static Synchronous Compensator ◽  
Facts Controllers ◽  
Angle Stability ◽  
Rotor Angle Stability ◽  
The Stability

This paper discusses the application of Fractional order PI controlled Static synchronous compensator for improvement rotor angle stability of inter connected power system. FACTS Controllers plays important role in enhancing the power system stability.Besides improving the stability margin of the power system it also aids the damping of inter area power oscillations. In the present work STATCOM is connected in multimachine power system .The dynamic response of the STATCOM is controlled by using fractional order controllers.The controller gains of the fractional controller are tuned by using PSO algorithm.It gives acceptable solutions to continuous non-linear systems with less computational effort. The performance of the proposed controller has been compared with integer order PI controllers at different locations of fault. In this paper a 3 machine 9 bus WSSC test power system is considered and simulated in MATLAB/SIMULINK.

scholarly journals Low-Speed Stability Optimization of Full-Order Observer for Induction Motor

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Xiangsheng Liu ◽  
Lin Ren ◽  
Yuanyuan Yang ◽  
Jun He ◽  
Zhengxin Zhou
Keyword(s):  
Induction Motor ◽  
Control Strategy ◽  
System Performance ◽  
System Stability ◽  
Feedback Gain ◽  
Unstable Region ◽  
Low Speed ◽  
Gain Matrix ◽  
Adaptive Law ◽  
The Stability

In terms of the instability of the full-order observer for the induction motor in the low-speed regenerative mode, the low-speed unstable region which leads to the extension of the commissioning cycle cannot be eliminated by the traditional adaptive law which aims at good system performance. It is proposed that the feedback gain matrix can control both the unstable region and the system performance both. To make a trade-off between the stability and performance by designing the feedback gain matrix is still an open problem. To solve this problem, first we analyze the cause of instability and derive constraints to ensure system stability by establishing a transfer function of the adaptive observing system for the speed. Then, with the derived constraints as the design criteria for the feedback gain matrix, a control strategy combining the weighted adaptive law with the improved feedback gain matrix is proposed to improve the stability at low speed. Finally, by comparing the traditional control strategy with the proposed control strategy through simulations and experiments, we show that the proposed control strategy achieves better performance with higher stability.

Synchronization of Fractional-Order Chaotic Systems with Uncertain Parameters

2010 ◽  
Vol 171-172 ◽  
pp. 723-727
Author(s):  
Hong Zhang ◽  
Qiu Mei Pu
Keyword(s):  
Fractional Order ◽  
Stability Theory ◽  
Chaotic Systems ◽  
Sliding Mode ◽  
System Stability ◽  
Order System ◽  
Uncertain Parameters ◽  
Mode Theory ◽  
Simulation Results ◽  
The Stability

For the synchronization of fractional-order chaotic systems with uncertain parameters, a controller based on sliding mode theory is presented. Based on the stability theory of fractional-order system, stability of the proposed method is analyzed. The theory is successfully applied to synchronize fractional Newton-Leipnik chaotic systems with uncertain parameters. The simulation results show the effectiveness of the proposed controller.

Gobal Optimization Based Power System Stablization with WAMS Time Delay Study

2012 ◽  
Vol 433-440 ◽  
pp. 7362-7367
Author(s):  
Zhang Lin ◽  
Di Chen Liu ◽  
Wu Jun ◽  
Qing Fen Liao ◽  
Yun Lei ◽  
...  
Keyword(s):  
Global Optimization ◽  
Time Delay ◽  
Power System ◽  
Low Frequency ◽  
System Stability ◽  
Area Measurement ◽  
Wide Area ◽  
Linear Matrix ◽  
Feedback Signal ◽  
The Stability

It is very important to take into consideration time delay in wide area power system stability; the design of PSS (Power System Stabilizer) should consider global optimization with WAMS (Wide Area Measurement System) time delay. Newly designed PSS should be insensitive to time delay and suppress internal low frequency oscillations. It is used as feedback signal and is real-time synchronous that WAMS signal shows. Power system is modeled with the consideration of time delay. LMI (Linear Matrix Inequalities) is used to solve the stability condition of time delay system. Based on the time-delay effect of the wide-area measurement signals, this paper redesigned the PSS with global optimization of power system. The attached two-area-four-machine system simulation illustrates that wide-area PSS designed by global optimization with the consideration of time-delay can limit internal low frequency oscillation with time-delay insensitivity, and improve the stability of power system. It implements global optimization of PSS with WAMS time delay stability.

BOCS Based Power System Stability Margin Estimation

2013 ◽  
Vol 805-806 ◽  
pp. 693-699
Author(s):  
Li Jie Ding ◽  
Hang Fan
Keyword(s):  
Power System ◽  
Continuous Measurement ◽  
Stability Margin ◽  
Stability Index ◽  
Power System Stability ◽  
System Stability ◽  
Motion State ◽  
Surface System ◽  
The Stability ◽  
Severe Disturbance

This paper focuses on the estimation of the stability index of a power system after a severe disturbance. The description of the stability margin has always been a challenging issue but by introducing a ball-on-concave-surface system, the assessment of the power system stability is equivalent to the analysis to the motion state of the ball on concave. According to the continuous measurement of PMU, the parameter of the concave can be determined which is useful to judge the stability margin of the power system. Tests have been conducted on the systems with two generators and results show it can be accurate and reliable.

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