Model-Free Optimal Control of VAR Resources in Distribution Systems: An Extremum Seeking Approach

Abstract The Rate of Penetration (ROP) is one of the key parameters related to the efficiency of the drilling process. Within the confines of operational limits, the drilling parameters affecting the ROP should be optimized to drill more efficiently and safely, to reduce the overall cost of constructing the well. In this study, a data-driven optimization method called Extremum Seeking (ES) is employed to automatically find and maintain the optimal Weight on Bit (WOB) which maximizes the ROP. The ES algorithm is a model-free method which gathers information about the current downhole conditions by automatically performing small tests with the WOB and executing optimization actions based on the test results. In this paper, this optimization method is augmented with a combination of a predictive and a reactive constraint handling technique to adhere to operational limitations. These methods of constraint handling within ES application to drilling are demonstrated for a maximal limit imposed on the surface torque, but the methods are generic and can be applied on various drilling parameters. The proposed optimization scheme has been tested with experiments on a downscaled drilling rig and simulations on a high-fidelity drilling simulator of a full-scale drilling operation. The experiments and simulations show the method's ability to steer the system to the optimum and to handle constraints and noisy data, resulting in safe and efficient drilling at high ROP.

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OPTIMAL CONTROL OF REACTIVE POWER AND VOLTAGE FOR DISTRIBUTION SYSTEMS

Power Systems and Power Plant Control ◽

10.1016/b978-0-08-034077-7.50015-9 ◽

1987 ◽

pp. 71-76

Author(s):

Pei-Hong Liao ◽

Hao-Zhong Cheng

Keyword(s):

Optimal Control ◽

Distribution Systems ◽

Reactive Power

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Model-Free Extremum Seeking Control of Bioprocesses: A Review with a Worked Example

Processes ◽

10.3390/pr8101209 ◽

2020 ◽

Vol 8 (10) ◽

pp. 1209

Author(s):

Laurent Dewasme ◽

Alain Vande Wouwer

Keyword(s):

Dynamic Models ◽

Operating Conditions ◽

Extremum Seeking ◽

Usual Practice ◽

Extremum Seeking Control ◽

Model Free ◽

Worked Example ◽

Current Trends ◽

Simple Simulation ◽

Recent Developments

Uncertainty is a common feature of biological systems, and model-free extremum-seeking control has proved a relevant approach to avoid the typical problems related to model-based optimization, e.g., time- and resource-consuming derivation and identification of dynamic models, and lack of robustness of optimal control. In this article, a review of the past and current trends in model-free extremum seeking is proposed with an emphasis on finding optimal operating conditions of bioprocesses. This review is illustrated with a simple simulation case study which allows a comparative evaluation of a few selected methods. Finally, some experimental case studies are discussed. As usual, practice lags behind theory, but recent developments confirm the applicability of the approach at the laboratory scale and are encouraging a transfer to industrial scale.

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