scholarly journals Stability of the Stochastic Model for Power Markets with Interval Parameters

2016 ◽  
Vol 2016 ◽  
pp. 1-10
Author(s):  
Zhanhui Lu ◽  
Mengfan Ji ◽  
Weijuan Wang ◽  
Gengyin Li
Keyword(s):  
Stochastic Model ◽  
Random Excitation ◽  
System Stability ◽  
Demand Elasticity ◽  
Power Markets ◽  
Stability Criteria ◽  
External Disturbances ◽  
Interval Model ◽  
Interval Parameters ◽  
Random Nature

Pertaining to the random nature of demand sides and the range of demand elasticity with suppliers and consumers, a stochastic model for power markets with interval parameters is described to illustrate uncertain external disturbances, which is a generalization of the Alvarado dynamic model, stochastic model, and interval model. The interval stochastic stability criteria of the provided model are investigated by the theory of economics, interval dynamical system, and the theory stability of stochastic differential equations. The conclusions indicate that the demand elasticity stable interval can be calculated and the random excitation intensity does not impact the system stability. Some numerical examples are given to show the applicability and validity of the obtained results from a statistical perspective.

scholarly journals The Interval Stability of an Electricity Market Model

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Weijuan Wang ◽  
Zhanhui Lu ◽  
Quanxin Zhu
Keyword(s):  
Electricity Markets ◽  
Electricity Market ◽  
System Stability ◽  
Market Model ◽  
Demand Elasticity ◽  
Interval Model ◽  
Market Dynamic ◽  
Inequality Theory ◽  
Market Framework ◽  
The Stability

Combined with the electric power market dynamic model put forward by Alvarado, an interval model of electricity markets is established and investigated in this paper pertaining to the range of demand elasticity with suppliers and consumers. The stability of an electricity market framework with demand elasticity interval is analyzed. The conclusions characterizing the interval model provided are derived by constructing a suitable Lyapunov function and using the theory of interval dynamical system in differential equations and matrix inequality theory and so forth. Applying the corollary obtained can judge the system stability by available data about demand elasticity. The obtained results are validated and illustrated by a case example.

scholarly journals Response analysis of random base excitation ona magnetic bearing rotor system

2019 ◽  
Vol 293 ◽  
pp. 04004
Author(s):  
Jinping Chen ◽  
Li Zhang ◽  
Yanyan Luo ◽  
Haining Zhang ◽  
Jun Liu
Keyword(s):  
Collision Detection ◽  
Random Excitation ◽  
Magnetic Bearing ◽  
Rotor System ◽  
Response Analysis ◽  
Random Response ◽  
Practical Application ◽  
External Disturbances ◽  
Response Characteristics ◽  
Auxiliary Bearing

The magnetic bearing-rotor system is subject to various external disturbances in practical application. Under certain control conditions, the random response characteristics of the magnetic bearing-rotor system are a particular concern. This paper analyzes the response characteristics of base of the magnetic bearing subjected to acceleration random excitation in the horizontal direction. First, the magnetic bearing-rotor system model is deduced. Then, the random response of the rotor under acceleration random excitation is derived. The probability of the collision of the rotor between the auxiliary bearing is calculated and the example is given. The paper conclusion provides a theoretical basis for the collision detection and prediction of the magnetic bearing-rotor system.

Justifying the Stabilization of a Marginally Stable Ship

2017 ◽  
Author(s):  
David Shekhtman ◽  
Dirk M. Luchtenburg
Keyword(s):  
Energy Dissipation ◽  
Closed Loop ◽  
Equations Of Motion ◽  
Marginal Stability ◽  
Stability Conditions ◽  
Stability Criteria ◽  
Benchmark Problem ◽  
Zero Energy ◽  
External Disturbances ◽  
Lyapunov Stability Criteria

As a precursor to capsize, marginal stability, resulting from incorrect loading conditions and crew negligence, poses a serious danger to ships. Therefore, as a benchmark problem for preventing capsize, the use of an actively controlled pendulum for the stabilization of a marginally stable ship was analyzed. Lyapunov stability criteria and closed loop eigenvalues were used to evaluate the extent to which a proposed pendulum controller could cope with different ship stability conditions. Equations of motion were solved to observe the controller’s performance under different damping conditions. The behavior of the controller yielded the following results: a marginally stable ship can be stabilized, as long as there is no right hand plane zero; energy dissipation is key to the stabilization of a marginally stable ship; the controller must have knowledge of the ship’s stability to prevent controller-induced excitation; and a stabilized tilted ship is more robust to external disturbances than a stabilized upright ship.

scholarly journals Motion stability of railway cars on bogies 18-100

2019 ◽  
Vol 78 (3) ◽  
pp. 149-154 ◽  
Author(s):  
Yu. S. Romen
Keyword(s):  
Rolling Stock ◽  
Transverse Displacement ◽  
External Disturbances ◽  
Factors Affecting ◽  
Bevel Gears ◽  
Rail System ◽  
Track System ◽  
Spring Suspension ◽  
The Difference ◽  
Random Nature

Stability of the rolling stock in a rail track is determined by the nature of the motion of the wheelsets under the influence of processes in the “wheel — rail” system and connections with the bogie and the carriage body. Factors affecting the motion of wheelsets are the irregularities of rail threads and the interaction forces in the “wheel — rail” system, which cause fluctuations in carriage hunting oscillation even in the absence of external disturbances. Parametric excitation of oscillations in the “carriage — track” system is caused by the difference in the radii of the rolling surfaces of the bevel gears with the transverse displacement of the wheelset in the track. This excitation is damped by the forces of resistance to rotation and displacement on the contact surface, the magnitude of which is inversely proportional to the rolling speed of the wheel. Therefore, with an increase in the speed of motion, the magnitude of resistance forces decreases and the intensity of processes determining hunting oscillations in the “wheel — rail” system increases. The excitatory factors on each of the wheelset of the bogie are of random nature and are not interconnected, therefore their vibrations are limited to the designs of the bogie and its connections with car body, which combine all the elements into a single system. Increasing the connectivity of the wheelsets and sidewalls of the bogie among themselves and with the carriage is the most appropriate solution for reducing hunting intensity. To do this, three-element bogies should reduce wear in the spring suspension, prohibiting the raising of the wedge above the plane of the supports of the bolster. To reduce the rotation of the bogie when hunting, bolster should be equipped with elastic contact bearings.

scholarly journals A Composite Nonlinear Controller for Power Systems with STATCOM under External Disturbances

2020 ◽  
Vol 18 (2) ◽  
pp. 107-117
Author(s):  
Adirak Kanchanaharuthai ◽  
Piraporn Konkhum ◽  
Kruwan Wongsurith
Keyword(s):  
Power Systems ◽  
State Feedback Control ◽  
System Stability ◽  
Control Technique ◽  
Nonlinear Controller ◽  
Static Synchronous Compensator ◽  
External Disturbances ◽  
Loop Dynamics ◽  
Dynamic Performances ◽  
Better Than

This paper concentrates on the design of a composite nonlinear stabilizing state feedback control for power systems with static synchronous compensator (STATCOM) with the help of a combination of backstepping strategy and a nonlinear disturbance approach. The disturbance observer is used to estimate unavoidably external disturbances. Thus, the obtained control law can be used to successfully stabilize the system stability and reject undesired external disturbances. In order to demonstrate the effectiveness of the developed process design, numerical simulation results are provided to indicate that the presented composite controller can improve dynamic performances, rapidly suppress system oscillations of the overall closed-loop dynamics, and despite having inevitably external disturbances, performs better than a conventional backstepping control technique.

scholarly journals Applying Tabu Search Optimisation in Zone Distribution System Reconfiguration A Stochastic Model

2021 ◽  
Vol 9 (2) ◽  
Author(s):  
Rana A. Abttan ◽  
Maad M. Mijwil
Keyword(s):  
Tabu Search ◽  
Stochastic Model ◽  
Network Topology ◽  
Distribution System ◽  
Network Reliability ◽  
Main Idea ◽  
System Stability ◽  
Network Reconfiguration ◽  
Suggested Technique ◽  
Distribution System Reconfiguration

The main idea in the distribution system is to reconfigure the network and to change the sectionalizing switches' state to reduce power loss and maintain system stability. In network reconfiguration, a key role is to find the appropriate network topology that does have the lowest losses during any conditions present within the network. Reliability, security, and system operating limitations are the most significant parts of the network reconfiguration that are suitable. In the work, the authors suggested to apply Tabu search optimisation technique to solve the problem of network reorganisation in the distribution system by creating a stochastic model of a virtual zone based on data prepared in a previous study by the first author. The stochastic model consists of four feeders and 106 buses. The validity of the suggested technique is verified by relying on standard practices and its ability to establish a correct network topology in the system distribution. This investigation determines that the suggested technique is excellently suitable for creating a virtual zone network and can be applied in reality.

The Response of Mechanical Systems to Random Excitation

1957 ◽  
Vol 24 (2) ◽  
pp. 248-251
Author(s):  
W. T. Thomson ◽  
M. V. Barton
Keyword(s):  
Dynamic Response ◽  
Mechanical Systems ◽  
Random Excitation ◽  
Fixed Frequency ◽  
Harmonic Force ◽  
Instantaneous Values ◽  
Random Nature

Abstract Mechanical systems are not always excited by a harmonic force of fixed frequency and amplitude. Often the excitation input is of random nature, and the response of the system displays no orderly trends. Instantaneous values and phase are meaningless in such cases, and the problem must be treated statistically. It is the purpose of this paper to outline such an approach as related to the dynamic response of structures.

Sensor faults tolerance control for a novel multi-rotor aircraft based on sliding mode control

2017 ◽  
Vol 233 (1) ◽  
pp. 180-196 ◽  
Author(s):  
Chunyang Fu ◽  
Yantao Tian ◽  
Cheng Peng ◽  
Xun Gong ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Angular Velocity ◽  
Sliding Mode Control ◽  
Sliding Mode ◽  
Lyapunov Theory ◽  
System Stability ◽  
Sensor Faults ◽  
External Disturbances ◽  
Outer Loop ◽  
Velocity Sensor ◽  
Mode Control

This paper deals with the controllers design using a novel siding mode control and proportional–derivative control for the trajectory tracking problem of a new multi-rotor aircraft, which experiences angular velocity sensor faults and external disturbances. The control system is divided into two parts: the inner loop for attitude subsystem and outer loop for position subsystem. For the inner loop, the angular velocity sensor faults, including bias, drift, loss of accuracy, and loss of effectiveness are considered as equivalent mismatched disturbances, while the system internal coupling, nonlinearity, and external disturbances are considered as equivalent matched disturbances. A novel sliding mode control approach is proposed for inner loop controller design, which includes a nonlinear disturbance observer to estimate both mismatched and matched disturbances, a novel switching surface based on the estimation of the mismatched disturbance to counteract its impact, a double power reaching law to attenuate the chattering problem, and a compensation for the matched disturbance to reduce the controller gains. The sensor faults are handled without fault detection and controller reconfiguration, making the method require less computation and easy implementation. The proposed method enhances the robustness without sacrificing the nominal properties. For outer loop, the proportional–derivative approach is used to design the virtual controller. The closed-loop system stability is proved by the Lyapunov theory. Finally, various simulation experiments are shown to validate the effectiveness, robustness, and the superiority of the proposed flight control scheme.

Sign in / Sign up

Export Citation Format

Share Document