Non-linear control of a fuel gas blending benchmark problem with added consumer dynamics

IF 3.9 2区计算机科学 Q2 AUTOMATION & CONTROL SYSTEMS

Journal of Process Control Pub Date : 2025-08-20 DOI:10.1016/j.jprocont.2025.103527

M.D. Sibiya, A.J. Wiid, J.D. le Roux, I.K. Craig

{"title":"Non-linear control of a fuel gas blending benchmark problem with added consumer dynamics","authors":"M.D. Sibiya, A.J. Wiid, J.D. le Roux, I.K. Craig","doi":"10.1016/j.jprocont.2025.103527","DOIUrl":null,"url":null,"abstract":"<div><div>This paper contributes to existing literature on fuel gas control by providing a feasible control solution with improved economic performance for an existing fuel gas control benchmark problem. Improved economic performance is achieved by implementing a non-linear model predictive controller (NMPC) that uses state estimates provided by a moving horizon estimator (MHE) and extended Kalman filter (EKF) for the fuel gas composition and flame speed index (FSI) to provide continuous inputs for the controller. Furthermore, the original fuel gas benchmark model is expanded to include consumer dynamics affecting fuel gas demand due to changes in the fuel gas heating value, making the model more representative of real industrial plants. The behaviour of an NMPC that neglects consumer dynamics (NMPC<span><math><msub><mrow></mrow><mrow><mn>1</mn></mrow></msub></math></span>) was compared against an NMPC that includes consumer dynamics (NMPC<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>).</div><div>The aim of the benchmark problem is to reduce the time-weighted average cost of fuel gas for three 46-hour cases, accounting for purchase costs and penalties for fuel gas specification violations. An optimal cost for each case is determined assuming ideal conditions and perfect control. The benchmark controller is a conventional multi-loop feedforward/feedback system and has an average cost for the three cases which is 38.5% higher than the optimal cost. The NMPC<span><math><msub><mrow></mrow><mrow><mn>1</mn></mrow></msub></math></span> controller has an average cost which is 33.9% higher than the optimal cost and better than the benchmark controller.</div><div>A new benchmark scenario was developed which includes the consumer dynamics. For the new scenario, NMPC<span><math><msub><mrow></mrow><mrow><mn>1</mn></mrow></msub></math></span> could not find a feasible solution, resulting in oscillations and specification violations. The oscillations would result in site-wide instabilities for all equipment using fuel gas. NMPC<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> was able to keep the process stable during these scenarios and maintain all specifications. This shows the necessity to include consumer dynamics for effective fuel gas blending control.</div></div>","PeriodicalId":50079,"journal":{"name":"Journal of Process Control","volume":"154 ","pages":"Article 103527"},"PeriodicalIF":3.9000,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Process Control","FirstCategoryId":"94","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0959152425001556","RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"AUTOMATION & CONTROL SYSTEMS","Score":null,"Total":0}

引用次数: 0

Abstract

This paper contributes to existing literature on fuel gas control by providing a feasible control solution with improved economic performance for an existing fuel gas control benchmark problem. Improved economic performance is achieved by implementing a non-linear model predictive controller (NMPC) that uses state estimates provided by a moving horizon estimator (MHE) and extended Kalman filter (EKF) for the fuel gas composition and flame speed index (FSI) to provide continuous inputs for the controller. Furthermore, the original fuel gas benchmark model is expanded to include consumer dynamics affecting fuel gas demand due to changes in the fuel gas heating value, making the model more representative of real industrial plants. The behaviour of an NMPC that neglects consumer dynamics (NMPC

_{1}

) was compared against an NMPC that includes consumer dynamics (NMPC

_{2}

The aim of the benchmark problem is to reduce the time-weighted average cost of fuel gas for three 46-hour cases, accounting for purchase costs and penalties for fuel gas specification violations. An optimal cost for each case is determined assuming ideal conditions and perfect control. The benchmark controller is a conventional multi-loop feedforward/feedback system and has an average cost for the three cases which is 38.5% higher than the optimal cost. The NMPC

_{1}

controller has an average cost which is 33.9% higher than the optimal cost and better than the benchmark controller.

A new benchmark scenario was developed which includes the consumer dynamics. For the new scenario, NMPC

_{1}

could not find a feasible solution, resulting in oscillations and specification violations. The oscillations would result in site-wide instabilities for all equipment using fuel gas. NMPC

_{2}

was able to keep the process stable during these scenarios and maintain all specifications. This shows the necessity to include consumer dynamics for effective fuel gas blending control.

查看原文本刊更多论文

具有附加消费者动态的燃气混合基准问题的非线性控制

本文对现有的燃气控制基准问题提供了一种经济性能更好的可行控制方案，对现有的燃气控制文献做出了贡献。通过实现非线性模型预测控制器（NMPC）来提高经济性能，该控制器使用移动水平估计器（MHE）提供的状态估计和扩展卡尔曼滤波器（EKF）对燃气成分和火焰速度指数（FSI）提供连续输入，为控制器提供连续输入。此外，对原有的燃气基准模型进行了扩展，纳入了由于燃气热值变化而影响燃气需求的消费者动态，使模型更能代表真实的工业厂房。将忽略消费者动态（NMPC1）的NMPC的行为与包含消费者动态（NMPC2）的NMPC进行比较。基准问题的目的是在考虑购买成本和违反燃气规范的处罚后，降低三个46小时情况下燃气的时间加权平均成本。在理想的条件和完美的控制下，确定每种情况的最优成本。基准控制器是传统的多环前馈/反馈系统，三种情况下的平均成本比最优成本高38.5%。NMPC1控制器的平均成本比最优成本高33.9%，优于基准控制器。开发了一个新的基准场景，其中包括消费者动态。对于新的场景，NMPC1无法找到可行的解决方案，导致振荡和规范违规。振荡将导致所有使用燃气的设备在整个现场不稳定。NMPC2能够在这些场景中保持流程稳定并维护所有规范。这表明有必要包括消费者动态有效的燃料气体混合控制。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Journal of Process Control 工程技术-工程：化工

CiteScore

7.00

自引率

11.90%

发文量

159

审稿时长

74 days

期刊介绍： This international journal covers the application of control theory, operations research, computer science and engineering principles to the solution of process control problems. In addition to the traditional chemical processing and manufacturing applications, the scope of process control problems involves a wide range of applications that includes energy processes, nano-technology, systems biology, bio-medical engineering, pharmaceutical processing technology, energy storage and conversion, smart grid, and data analytics among others. Papers on the theory in these areas will also be accepted provided the theoretical contribution is aimed at the application and the development of process control techniques. Topics covered include: • Control applications• Process monitoring• Plant-wide control• Process control systems• Control techniques and algorithms• Process modelling and simulation• Design methods Advanced design methods exclude well established and widely studied traditional design techniques such as PID tuning and its many variants. Applications in fields such as control of automotive engines, machinery and robotics are not deemed suitable unless a clear motivation for the relevance to process control is provided.