Extremum Control for Optimal Operating Point Determination and Set Point Optimization Via Sliding Modes

2000 ◽  
Vol 122 (4) ◽  
pp. 719-724 ◽  
Author(s):  
I˙brahim Haskara ◽  
U¨mit O¨zgu¨ner ◽  
Jim Winkelman
Keyword(s):  
Time Scale ◽  
Closed Loop ◽  
Sliding Mode ◽  
Operation Mode ◽  
Research Problem ◽  
Optimization Method ◽  
Optimal Operation ◽  
Operating Point ◽  
Limited Information ◽  
Optimal Operating

In the design of a control system, it is often desirable to operate at the peak of an appropriate performance surface which characterizes the performance of the closed-loop operation. However, in many cases, only limited information might be available on the plant and the desired performance criterion which makes a priori determination of such an optimal operation mode difficult in the first place. The online identification of an optimal operating point and the development of a controller structure which enables the system to robustly operate at such a point constitute a remarkable research problem with this motivation. In this paper, a two-time scale sliding mode optimization method is studied for this purpose. The adopted scheme assumes a regulative controller which produces an equilibria for the closed-loop system parametrized by a free control parameter and employs a sliding mode optimization method to adapt this parameter in a slower time scale to increase the performance of the overall system. A simulation study is summarized to illustrate the approach. [S0022-0434(00)01004-2]

Derivation of Monthly Operating Rules for Cascade Hydropower Stations Based on SVM

2013 ◽  
Vol 838-841 ◽  
pp. 1673-1676
Author(s):  
Ting Zhou ◽  
Chang Ming Ji ◽  
Bi Kui Zhao
Keyword(s):  
River System ◽  
Optimization Method ◽  
Optimal Operation ◽  
Support Vector ◽  
System Operation ◽  
Optimal Operating ◽  
Operating Rules ◽  
Hydropower Stations ◽  
System Power

In order to promote the efficiency of actual hydropower system operation under limited inflow forecast, an Implicit Stochastic Optimization method using Support Vector Machine (SVM) theory is proposed in this paper to derive long-term optimal operating rules. By applying the model to the Jinsha-Yangtze river system which is the largest hydropower base in China, fitting performance of operating rules is explained and evaluated. System simulation results are given and compared to deterministic optimal operation. Power output processes comparison shows that the average annual system power generation in two scenarios are 395TWh and 392TWh, and the overall operation processes are in well accordance with explicable inconsistency, which proves the efficiency of SVM in operating rules derivation for hydropower stations.

scholarly journals Choosing the optimal operating mode of a gas condensate well taking into account the relaxation deformation of rocks

2021 ◽  
Vol 134 (3) ◽  
pp. 50-54
Author(s):  
Т. А. Samadov ◽  
◽  
B. Z. , Кazymov ◽  
S. H. Novruzova ◽  
◽  
...  
Keyword(s):  
Operation Mode ◽  
Operating Mode ◽  
Optimal Operation ◽  
Gas Condensate ◽  
Reservoir Pressure ◽  
Optimal Operating ◽  
Reservoir Rocks ◽  
Bottom Hole ◽  
Sand Accumulation ◽  
Current Operating

The article proposes a method for selecting the optimal operation mode of a gas condensate well without sand accumulation in the bottom, taking into account the relaxation deformation of reservoir rocks during the development of a gas condensate deposit in the depletion mode. This method simultaneously allows you to determine the required current operating volume of produced condensate (as well as gas), as well as bottom-hole and contour values of reservoir pressure, condensate saturation and porosity of the reservoir, corresponding to the selected optimal operation mode of the well.

A novel method to determine the optimal operating point for centrifugal pumps applied in photovoltaic pumping systems

Solar Energy ◽  
2021 ◽  
Vol 221 ◽  
pp. 46-59
Author(s):  
Wanderley Sena dos Santos ◽  
Pedro Ferreira Torres ◽  
Alaan Ubaiara Brito ◽  
Alex Renan Arrifano Manito ◽  
Gilberto Figueiredo Pinto Filho ◽  
...  
Keyword(s):  
Operating Point ◽  
Centrifugal Pumps ◽  
Optimal Operating ◽  
Novel Method

scholarly journals Software Sensor to Enhance Online Parametric Identification for Nonlinear Closed-Loop Systems for Robotic Applications

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3653
Author(s):  
Lilia Sidhom ◽  
Ines Chihi ◽  
Ernest Nlandu Kamavuako
Keyword(s):  
Degrees Of Freedom ◽  
Closed Loop ◽  
Sliding Mode ◽  
Robot Manipulator ◽  
Parametric Identification ◽  
Recursive Least Squares ◽  
Unknown Parameters ◽  
Closed Loop Identification ◽  
Input Variables ◽  
Robotic Applications

This paper proposes an online direct closed-loop identification method based on a new dynamic sliding mode technique for robotic applications. The estimated parameters are obtained by minimizing the prediction error with respect to the vector of unknown parameters. The estimation step requires knowledge of the actual input and output of the system, as well as the successive estimate of the output derivatives. Therefore, a special robust differentiator based on higher-order sliding modes with a dynamic gain is defined. A proof of convergence is given for the robust differentiator. The dynamic parameters are estimated using the recursive least squares algorithm by the solution of a system model that is obtained from sampled positions along the closed-loop trajectory. An experimental validation is given for a 2 Degrees Of Freedom (2-DOF) robot manipulator, where direct and cross-validations are carried out. A comparative analysis is detailed to evaluate the algorithm’s effectiveness and reliability. Its performance is demonstrated by a better-quality torque prediction compared to other differentiators recently proposed in the literature. The experimental results highlight that the differentiator design strongly influences the online parametric identification and, thus, the prediction of system input variables.

scholarly journals Synchronous Generator Rectification System Based on Double Closed-Loop Control of Backstepping and Sliding Mode Variable Structure

Electronics ◽  
2021 ◽  
Vol 10 (15) ◽  
pp. 1832
Author(s):  
Jinfeng Liu ◽  
Xin Qu ◽  
Herbert Ho-Ching Iu
Keyword(s):  
Closed Loop ◽  
Control Structure ◽  
Low Voltage ◽  
Sliding Mode ◽  
Variable Structure ◽  
Synchronous Generator ◽  
Closed Loop Control ◽  
High Current ◽  
Loop Control ◽  
Sliding Mode Variable Structure

Low-voltage and high-current direct current (DC) power supplies are essential for aerospace and shipping. However, its robustness and dynamic response need to be optimized further on some special occasions. In this paper, a novel rectification system platform is built with the low-voltage and high-current permanent magnet synchronous generator (PMSG), in which the DC voltage double closed-loop control system is constructed with the backstepping control method and the sliding mode variable structure (SMVS). In the active component control structure of this system, reasonable virtual control variables are set to obtain the overall structural control variable which satisfied the stability requirements of Lyapunov stability theory. Thus, the fast-tracking and the global adjustment of the system are realized and the robustness is improved. Since the reactive component control structure is simple and no subsystem has to be constructed, the SMVS is used to stabilize the system power factor. By building a simulation model and experimental platform of the 5 V/300 A rectification module based on the PMSG, it is verified that the power factor of the system can reach about 98.5%. When the load mutation occurs, the DC output achieves stability again within 0.02 s, and the system fluctuation rate does not exceed 2%.

High-Performance Motion Control With Slosh: A Constrained Sliding Mode Approach

2008 ◽  
Author(s):  
Hanz Richter ◽  
Kedar B. Karnik
Keyword(s):  
High Speed ◽  
High Performance ◽  
Design Methodology ◽  
Closed Loop ◽  
Sliding Mode ◽  
Initial Conditions ◽  
Rectilinear Motion ◽  
Industrial Setting ◽  
Open Container ◽  
Nominal Performance

The problem of controlling the rectilinear motion of an open container without exceeding a prescribed liquid level and other constraints is considered using a recently-developed constrained sliding mode control design methodology based on invariant cylinders. A conventional sliding mode regulator is designed first to address nominal performance in the sliding mode. Then an robustly-invariant cylinder is constructed and used to describe the set of safe initial conditions from which the closed-loop controller can be operated without constraint violation. Simulations of a typical transfer illustrate the usefulness of the method in an industrial setting. Experimental results corresponding to a high-speed transfer validate the theory.

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