Browsing by Author "Skworcow, P."

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    Burst Detection in Water Distribution Systems via Active Identification Procedure
    (Exeter University, 2011-09-05) Skworcow, P.; Ulanicki, Bogumil
    This paper considers an approach to detect unreported pipe bursts in water distribution systems via active identification procedure. The approach involves carrying out an e-FAVOR test; results of the test are used together with a hydraulic model of the network as the inputs to a software tool, which is under development. New bursts indicators are proposed, which are considered to be more resilient to modelling errors and to inaccurate reading of the pressure logger elevation. The methodology was tested in practice in a manual manner and proved to be effective, but time consuming. In this paper some automatic analysis algorithms, developed to speed up the burst detection process, are described and tested via simulations. Results to date indicate suitability of the proposed burst indicators and the developed algorithms.
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    Bursts Identification in Water Distribution Systems
    (ASCE, 2009-05-17) Borovik, Irina; Ulanicki, Bogumil; Skworcow, P.
    The leakage reduction problem as a whole is complex and requires co-ordinated actions in different areas of water network management, such as: direct detection and repair of existing bursts, general pipe rehabilitation programmes and operational pressure control. Water companies undertake a mixture of these complimentary actions. General pipe rehabilitation is the most costly and long term action, but is undertaken to improve a number of different factors including leakage and water quality. Operational pressure control is a cost-effective action for reducing leakage over whole sub-networks, and for reducing the risk of further leaks by smoothing pressure variations and is the subject of ongoing research. Detection and repair actions are targeted at sub-networks where bursts are present. Benefits of quick burst repair include reduced water losses, reduced disruption to traffic, reduced consequent losses (e.g. from flooding), and also reduced disruption to customers' supplies, which is an important water industry performance measure. The existing methods typically use passive identification approach whilst the presented approach is based on the active identification procedure. The proposed burst location algorithm is based on comparing data by means of statistical analysis from a simple field experiment with results of water network simulation. An extended network hydraulic simulator is used to model pressure dependent leakage terms. The presence of a burst changes the flow pattern and also pressure at network nodes, which may be used to estimate the burst size and its location. The influence of such random factors as demand flows and background leakage on the process of burst detection is also considered. The field experiment is an extended fixed and variable orifice (e-FAVOR) test. During this test inlet pressure is being stepped up and down and the following variables are measured: inlet flow, inlet pressure (head) and pressure at a number of selected sensitive nodes. The method consists of three stages and uses two different models; one is inlet flow model (IFM) to represent the total inlet flow and another is the extended hydraulic model to simulate different burst locations. Initially the presence of a potential burst is investigated. If this is confirmed values of the demand, background leakage flow and burst flow in IFM are subsequently estimated. These are used to identify the burst site at the third stage of the method. The approach has been validated by solving a practical case study with correct diagnosis of the existing problems.
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    Combined Energy and Pressure Management in Water Distribution Systems
    (ASCE, 2009-05-17) Skworcow, P.; AbdelMeguid, Hossam Saadeldin; Ulanicki, Bogumil; Bounds, Peter; Patel, Ridwan
    In this paper a method is proposed for combined energy and pressure management via integration and coordination of pump scheduling with pressure control aspects. The proposed solution involves: formulation of an optimisation problem with the cost function being the total cost of water treatment and pumps energy usage, utilisation of an hydraulic model of the network with pressure dependent leakage, and inclusion of a PRV model with the PRV set-points included as a set of decision variables. Such problem formulation led to the optimizer attempting to reduce both energy usage and leakage. The developed algorithm has been integrated into a modelling, simulation and optimisation environment called FINESSE. The case study selected is a major water supply network, being part of Yorkshire Water Services, with a total average demand of 400 l/s.
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    Couch-based motion compensation: modelling, simulation and real-time experiments
    (IOP Publishing, 2012) Haas, O. C. L.; Skworcow, P.; Paluszczyszyn, D.; Sahih, A.; Ruta, M.; Mills, J. A.
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    Developing scenarios for future utility provision
    (2012) Ulanicki, Bogumil; Strzelecka, A.; Skworcow, P.; Janus, T.
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    Improving numerical efficiency of water networks models reduction algorithm
    (Drukarnia Oficyny Wydawniczej Politechniki Wroclawskiej, 2014) Paluszczyszyn, D.; Skworcow, P.; Ulanicki, Bogumil
    Nowadays, it is common that water distribution network (WDN) models contain thousands of elements to accurately replicate hydraulic behaviour and topographical layout of real systems. Such models are appropriate for simulation purposes, however optimisation tasks are much more computationally demanding, hence simplified models are required. Variables elimination is a mathematical method for the reduction of such large-scale models described by non-linear algebraic equations. The approach benefits of preserving the non-linearity of the original WDN model and approximates the original model at wide range of operating conditions. However its compute-intensive nature demanded that its implementation should take into account the development in programming languages and the recently released libraries allowing an optimisation of the executable program for multi-core machines. This will ensure that model reduction application will be able to cope with complex topologies of large size networks. In this paper the process of design and development of the research software is described with focus put on the emerged computational research aspects. It is demonstrated that utilisation of parallel programming techniques and sparse matrices ordering algorithms drastically decrease computational time of the model simplification.
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    Mathematical modelling of a hydraulic controller for PRV flow modulation
    (CRC Press/Balkema, 2009-09-01) Ulanicki, Bogumil; AbdelMeguid, Hossam Saadeldin; Skworcow, P.
    The main purpose of this paper is to describe a new experimental setup for testing static and dynamic behav-iour of the AQUAI-MOD® hydraulic controller coupled with a standard PRV, as well as to develop mathe-matical models which represent static and dynamic properties of such a system. The controller has been ex-perimentally tested to assess its performance in different conditions and operating ranges. The device in all cases has showed good performance by modulating the outlet pressure as expected between two points corre-sponding to the minimum and the maximum flow. The mathematical models of the controller have been im-plemented and solved using the Mathematical software package to represent both steady state and dynamics conditions. The results of the steady state model have been compared with experimental data and showed a good agreement in the magnitude and trends. The steady state model can be used to simulate the behaviour of a PRV and the AQUAI-MOD® hydraulic controller in typical network applications. It can be also used at the design stage and to compute the required adjustments for the minimum and maximum head set points before installing the controller in the field. Subsequently, a dynamic model of the PRV and the AQUAI-MOD® hy-draulic controller system has been developed and solved. Again the dynamic model showed a good agreement with the experimental data. The main time constant in the system model corresponds to the movement of the main element of the PRV. The research presented here has been carried out within the Neptune project (www.neptune.ac.uk) which is a Strategic Partnership between EPSRC, ABB, Yorkshire Water and United Utilities.
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    Mathematical modelling of a hydraulic controller for PRV flow modulation.
    (Taylor Francis, 2010) AbdelMeguid, Hossam Saadeldin; Skworcow, P.; Ulanicki, Bogumil
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    Mathematical modelling of a hydraulic controller for PRV flow modulation.
    (International Water Association Publishing, 2011) AbdelMeguid, Hossam Saadeldin; Skworcow, P.; Ulanicki, Bogumil
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    Model Predictive Control for Energy and Leakage Management in Water Distribution Systems
    (2010-09-07) Skworcow, P.; Ulanicki, Bogumil; AdbelMeguid, Hossam; Paluszczyszyn, D.
    This paper considers development of a methodology for an on-line energy and leakage management in water distribution systems, formulated within a model predictive control framework. The approach involves calculation of control actions, i.e. time schedules for pumps, valves and sources, to minimize the costs associated with energy used for water pumping and treatment and water losses due to leakage, whilst satisfying all operational constraints. The process of computing the control action utilises EPAnet hydraulic simulator, a mathematical modelling language called GAMS and a non-linear programming solver called CONOPT. The proposed control scheme has been integrated with an industrial SCADA system from ABB and interfaced with an actual medium-scale water distribution systems being part of Yorkshire Water Services. The scheme is currently being tested using on-line telemetry data. It has been operational for over 1 month with 1 hour sampling time and the preliminary results described in this paper indicate a potential for savings of 30% of the cost of electrical energy.
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    Model Predictive Control for Real-time Tumour Motion Compensation in Adaptive Radiotherapy
    (2012) Paluszczyszyn, D.; Skworcow, P.; Haas, O.C. L.; Burnham, K. J.; Mills, J. A.
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    Modelling and simulation of utility service provision for sustainable communities
    (Walter de Gruyter, 2012) Strzelecka, A.; Skworcow, P.
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    Modelling and simulation of water distribution systems with quantised state system methods
    (Elsevier, 2015-09-01) Skworcow, P.; Ulanicki, Bogumil; Paluszczyszyn, D.
    The work in this paper describes a study of quantised state systems in order to formulate a new framework within which water distribution systems can be modelled and simulated. In contrast to the classic time-slicing simulators, depending on the numerical integration algorithms, the quantisation of system states would allow accounting for the iscontinuities exhibited by control elements in a more efficient manner, and thereby, offer a significant increase in speed of the simulation of water network models.The proposed approach is evaluated on a case study and compared against the results obtained from the Epanet2 simulator and OpenModelica.
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    Modelling, simulation and optimisation of utility–service provision for households: case studies
    (Procedia Engineering, Elsevier, 2013-09-04) Strzelecka, A.; Skworcow, P.; Ulanicki, Bogumil
    In the research presented in this paper household case studies were considered. Main objective of this research is to investigate models and algorithms for alternative approaches to current utility–service provision. This paper is focused on case studies that consider standard solutions to utility–service provision problems and propose improvements to these solutions. Results are obtained using a simulation system developed in C#. The simulation system evaluates feasibility of proposed candidate solution (so-called transformation graphs) that can be created manually or generated automatically. The simulation system uses data stored in an XML database implemented using eXist-db.
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    A new method of modelling and simulation of water networks with discontinuous control elements
    (2012) Paluszczyszyn, D.; Skworcow, P.; Ulanicki, Bogumil
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    Online Simplification of Water Distribution Network Models
    (Exeter University, 2011-09-05) Paluszczyszyn, D.; Skworcow, P.; Ulanicki, Bogumil
    This paper presents an implementation of the simplification algorithm of water distribution network (WDN) models for the purpose of inclusion to the online optimisation strategy for the energy and leakage management in WDN, formulated within a model predictive control framework. The advantage of the online model reduction is adaptation to abnormal situations and structural changes in a network. The implementation was carried out with the utilisation of nowadays parallel programing techniques to distribute the simplification tasks across multiple CPU treads. This resulted in significant reduction of the computational time required for the simplification process of the large–scale WDN models. The authors also highlighted a problem of the energy distribution when the reduced and original models were compared.
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    Online simplification of water distribution network models for optimal scheduling
    (IWA Publishing, 2012) Paluszczyszyn, D.; Skworcow, P.; Ulanicki, Bogumil
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    Optimal pump scheduling with pressure control aspects: case studies
    (CRC Press/Balkema, 2009-09-01) Skworcow, P.; AbdelMeguid, Hossam Saadeldin; Ulanicki, Bogumil; Bounds, Peter
    In this paper a method for combined energy and pressure management via integration of pump scheduling with pressure control aspects is described and applied to a medium scale water supply network. The method is based on formulating and solving an optimisation problem and involves utilisation of an hydraulic model of the network with pressure dependent leakage and inclusion of a PRV model with the PRV set-points included in a set of decision variables. Such problem formulation led to the optimizer attempting to reduce both energy usage and leakage. Case study considered revealed potential for substantial saving in electrical energy cost using the proposed method. This research is sponsored by and is a part of EPSRC Neptune project www.neptune.ac.uk). The authors are grateful to Ridwan Patel of Yorkshire Water Services for providing the data used in this paper.
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    An optimal sequence of tasks for autonomous learning systems.
    (IEEE, 2011) Rudek, R.; Rudek, A.; Skworcow, P.
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    Optimisation of pump and valve schedules in complex large-scale water distribution systems using GAMS modelling language
    (Procedia Engineering, Elsevier, 2013-09-04) Skworcow, P.; Paluszczyszyn, D.; Ulanicki, Bogumil; Rudek, R.; Belrain, T.
    This paper considers optimisation of pump and valve schedules in complex large-scale water distribution networks (WDN). An optimisation model is automatically generated in GAMS language from a hydraulic model in EPANET format and from additional files describing operational constraints, electricity tari s and pump station configurations. The paper describes how each hydraulic component is modelled. To reduce the size of the optimisation problem the full hydraulic model is simplified using module reduction algorithm, while retaining the nonlinear characteristics of the model. Subsequently, a nonlinear programming solver CONOPT is used to solve the optimisation model. The proposed approached was tested on a large-scale WDN model provided in EPANET format. The considered WDN included complex structures and interactions between pump stations. Solving of several scenarios considering di erent horizons, time steps, operational constraints and topological changes demonstrated ability of the approach to automatically generate and solve optimisation problems for variety of requirements.