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  • Journal article
    Cecílio IM, Ottewill JR, Fretheim H, Thornhill NFet al., 2014,

    Multivariate Detection of Transient Disturbances for Uni- and Multirate Systems

    , IEEE Transactions on Control Systems Technology, Vol: 23, Pages: 1477-1493, ISSN: 1558-0865

    This paper presents a method to detect transientdisturbances in a multivariate context, and an extension of thatmethod to handle multirate systems. Both methods are basedon a time series analysis technique known as nearest neighbors,and on multivariate statistics implemented as a singular valuedecomposition. The motivation for these developments is thatthere is an increasing industrial requirement for the analysisof data sets comprising measurements from industrial processestogether with their associated electrical and mechanicalequipment. These systems are increasingly affected by transientdisturbances, and their measurements are commonly sampledat different rates. This paper demonstrates superior resultswith the multivariate method in comparison with the univariateapproach, and with the multirate method in comparison toa unirate method, for which the fast-sampled measurementshad to be downsampled. The method is demonstrated onexperimental and industrial case studies.
  • Conference paper
    Romero DD, Thornhill NF, 2014,

    Integration, navigation and exploration of plant topology networks using the property-graph model

    , 2014 IEEE/SICE International Symposium on System Integration, Publisher: IEEE, Pages: 743-748

    Understanding the process topology is essential for many process-systems engineering activities. Previous works in this area have explored the extraction of connectivity and causality knowledge (plant topology) from different sources of engineering data by following qualitative and quantitative methods. A few works, however, have focused on how to integrate, store, and visualize models that can represent the interactions among the different items in a chemical plant. This paper proposes a method for integration, navigation and exploration of topology based on property-graphs, which can support the study of disturbance propagation in chemical plants.
  • Conference paper
    Arroyo E, Schulze D, Christiansen L, Fay A, Thornhill NFet al., 2014,

    Derivation of diagnostic models based on formalized process knowledge

    , 19th IFAC World Congress, 2014, Publisher: International Federation of Automatic Control, Pages: 3456-3464, ISSN: 1474-6670
  • Conference paper
    Ersdal AM, Fabozzi D, Imsland L, Thornhill NFet al., 2014,

    Model predictive control for power system frequency control taking into account imbalance uncertainty

    , 19th IFAC World Congress 2014, Publisher: International Federation of Automatic Control, Pages: 981-986, ISSN: 1474-6670
  • Journal article
    Cecilio IM, Ottewill JR, Pretlove J, Thornhill NFet al., 2014,

    Nearest neighbors method for detecting transient disturbances in process and electromechanical systems

    , Journal of Process Control, Vol: 24, Pages: 1382-1393, ISSN: 1873-2771

    Transient disturbances are increasingly relevant in process industries which rely on electromechanical equipment. Existing data-driven methods for detecting transient disturbances assume a distinct amplitude or time-frequency component. This paper proposes a detection method which is more generic and handles any short-term deviation of a measurement from its overall trend, regardless of whether the trend incorporates features such as oscillations, noise or changes in operation level. The method is based on a nearest neighbors technique and builds a vector of anomaly indices which are high for the period with the transient disturbance. The paper includes analyses of the statistical significance of the threshold proposed and of the sensitivity of the parameters, and it also suggests a color map to visualize the detection results. The method is demonstrated on experimental and industrial case studies.
  • Journal article
    Yang Y, Farid SS, Thornhill NF, 2014,

    Data mining for rapid prediction of facility fit and debottlenecking of biomanufacturing facilities

    , JOURNAL OF BIOTECHNOLOGY, Vol: 179, Pages: 17-25, ISSN: 0168-1656
  • Journal article
    Ikram W, Petersen S, Orten P, Thornhill NFet al., 2014,

    Adaptive multi-channel transmission power control for industrial wireless instrumentation

    , IEEE Transactions on Industrial Informatics, Vol: 10, Pages: 978-990, ISSN: 1551-3203

    The adoption of wireless technology for industrial wireless instrumentation requires high-quality communication performance. The use of transmission power control (TPC) can help address industrial issues concerning energy consumption, interference, and fading. This paper presents a TPC algorithm designed for industrial applications based on theoretical and empirical studies. It is shown that the proposed algorithm adapts to variations in link quality, and is hardware-independent and practical.
  • Conference paper
    Yang Y, Farid SS, Thornhill NF, 2014,

    Rapid prediction of facility fit and debottlenecking of antibody purification facilities
  • Conference paper
    Yang Y, Farid SS, Thornhill NF, 2014,

    Rapid prediction of facility fit and debottlenecking of antibody purification facilities
  • Conference paper
    Xenos DP, Kopanos GM, Pistikopoulos EN, Thornhill NF, Cicciotti Met al., 2014,

    Operational optimization of compressors in parallel considering condition-based maintenance

    , 24th European Conference on Computer Aided Process Engineering (ESCAPE 24), Pages: 1213-1218, ISSN: 1570-7946

    This paper suggests an optimization framework for the process and maintenance operations of a network of compressors. The health condition of a compressor varies during its operation due to mechanically degrading effects (e.g. fouling and corrosion) which results in decreasing performance and increasing power consumption. Currently, the industrial maintenance strategy considers preventive maintenance cycles, i.e. maximum running time of the compressors. Typically, the maintenance schedule of a compressor is examined separately without considering the interactions between the compressor and the overall process. In this work, the increase in the power consumption of each compressor is linearly correlated to the periods of continuous operation, and the results demonstrate that the simultaneous optimization of condition-based maintenance and operation reduces the overall costs. © 2014 Elsevier B.V.
  • Conference paper
    Cicciotti M, Xenos DP, Bouaswaig AEF, Thornhill NF, Martinez-Botas RFet al., 2014,

    ONLINE PERFORMANCE MONITORING OF INDUSTRIAL COMPRESSORS USING MEANLINE MODELLING

    , ASME Turbo Expo: Turbine Technical Conference and Exposition, Publisher: AMER SOC MECHANICAL ENGINEERS
  • Conference paper
    Budinis S, Thornhill NF, 2014,

    An integrated control technique for compressor operation

    , United-Kingdom-Automatic-Control-Council (UKACC) 10th International Conference on Control (CONTROL), Publisher: IEEE, Pages: 444-449
  • Conference paper
    Mechleri ED, Thornhill NF, Biliyok C, 2014,

    Dynamic simulation and control of post-combustion CO capture with MEA in a gas fired power plant

    , 24th European Conference on Computer Aided Process Engineering (ESCAPE 24), Pages: 619-624, ISSN: 1570-7946

    This paper presents a dynamic model of a post combustion CO capture plant via chemical absorption using monoethanolamine (MEA) for natural gas combined cycle (NGCC) power plants. Insight regarding the process dynamics due to various disturbances caused by the operation of the power plant is presented and a control structure is proposed, based on heuristics. The performance of the proposed control scheme was evaluated by changing the flue gas flow rate which is commonly induced in the operation of power plants such as during start-up, shutdown and cyclic loading. Consideration has also been given to the variations to the control tuning due to the lower composition of CO in NGCC plant compared to coal fired power plants. The results have shown that with the implementation of the proposed control scheme, the flexible operation of the power plant in combination with the capture plant can be maintained. © 2014 Elsevier B.V.
  • Conference paper
    Xenos DP, Cicciotti M, Bouaswaig AEF, Thornhill NF, Martinez-Botas Ret al., 2014,

    MODELING AND OPTIMIZATION OF INDUSTRIAL CENTRIFUGAL COMPRESSOR STATIONS EMPLOYING DATA-DRIVEN METHODS

    , ASME Turbo Expo: Turbine Technical Conference and Exposition, Publisher: AMER SOC MECHANICAL ENGINEERS
  • Conference paper
    Romero DD, Graven T-G, Thornhill NF, 2014,

    Towards the Development of a Tool for Visualising Plantwide Dependencies

    , 19th IEEE International Conference on Emerging Technology and Factory Automation (ETFA), Publisher: IEEE
  • Conference paper
    Cicciotti M, Bouaswaiga AEF, Martinez-Botas RF, Xenos DP, Thornhill NF, Manenti Fet al., 2014,

    Simultaneous Nonlinear Reconciliation and Update of Parameters for Online Use of First-Principles Models: An Industrial Case-Study on Compressors

    , 24th European Conference on Computer Aided Process Engineering (ESCAPE 24), Pages: 457-462, ISSN: 1570-7946

    Online uses of first-principles models include nonlinear model predictive control, softsensors, real-time optimization, and real-time process monitoring, among others. The industrial implementation of these applications needs accurate adaptive models and reconciled data. The simultaneous reconciliation and update of parameters of a first- principles model can be achieved using an optimization framework that exploits physical and analytical redundancy of information. This paper demonstrates this concept by means of an industrial case-study. The case-study is a multi-stage centrifugal compressor for which a first-principles model was recently developed. The update of the model parameters is necessary to capture slowly progressing mechanical degradation (e.g. due to fouling and erosion). The reconciliation of the data is necessary for reducing downtime of the online model-based applications caused by gross errors. Two industrial cases including sensor failures were analysed. Applying the proposed framework, it was possible to reconcile the measurements for both cases. © 2014 Elsevier B.V.
  • Conference paper
    Romero DD, Graven T-G, Thornhill NF, 2014,

    Investigations on information-rich visualizations to explore process connectivity and causality

    , 24th European Conference on Computer Aided Process Engineering (ESCAPE 24), Pages: 811-816, ISSN: 1570-7946

    Complexity in large-scale chemical processes poses a challenge to engineers who need to understand causality and interconnectivity. Previous work has already taken advantage of the use of visualization for alarm correlation and plant-wide oscillation detection for small scale example processes, but the resulting correlation maps are limited in the number of variables that can be easily managed. This paper proposes a new approach to the visualization of connectivity information, which is capable of representing a large number of connections between process variables and units, as well as process-specific information and alarm history. The novel visualization is based on the Circos framework which is widely used for analysis of connectivity and causality in the field of genomics. The benefit of adapting information-rich visualizations for the field of process systems engineering will be discussed based on an academic use-case. © 2014 Elsevier B.V.
  • Conference paper
    Xenos DP, Thornhill NF, Cicciotti M, Bouaswaig AEFet al., 2014,

    Preprocessing of Raw Data for Developing Steady-State Data-Driven Models for Optimizing Compressor Stations

    , United-Kingdom-Automatic-Control-Council (UKACC) 10th International Conference on Control (CONTROL), Publisher: IEEE, Pages: 438-443
  • Conference paper
    Cecílio IM, Ersdal AM, Fabozzi D, Thornhill NFet al., 2013,

    An Open-Source Educational Toolbox for Power System Frequency Control Tuning and Optimization

    , 4th European Innovative Smart Grid Technologies (ISGT), Publisher: IEEE
  • Conference paper
    P Kunjumuhammed L, C Pal B, Anaparthi K, F Thornhill Net al., 2013,

    Effect of wind penetration on power system stability

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Contact us

Nina Thornhill, ABB/RAEng Professor of Process Automation
Centre for Process Systems Engineering
Department of Chemical Engineering
Imperial College London
South Kensington Campus, London SW7 2AZ

Tel: +44 (0)20 7594 6622
Email: n.thornhill@imperial.ac.uk