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  • Conference paper
    Trovato G, Tindemans SH, Strbac G, 2013,

    Demand Response Contribution to Effective Inertia for System Security in the GB 2020 Gone Green Scenario

    , IEEE Innovative Smart Grid Technologies (ISGT) Europe 2013
  • Journal article
    Bettiol P, Vinter RB, 2013,

    Estimates on trajectories in a closed set with corners for (t,x) dependent data

    , Mathematical Control and Related Fields, Vol: 3, Pages: 245-267, ISSN: 2156-8472

    Estimates on the distance of a given process from the set of processes that satisfy a specified state constraint in terms of the state constraint violation are important analytical tools in state constrained optimal control theory; they have been employed to ensure the validity of the Maximum Principle in normal form, to establish regularity properties of the value function, to justify interpreting the value function as a unique solution of the Hamilton-Jacobi equation, and for other purposes. A range of estimates are required, which differ according the metrics used to measure the `distance' and the modulus θ(h) of state constraint violation h in terms of which the estimates are expressed. Recent research has shown that simple linear estimates are valid when the state constraint set A has smooth boundary, but do not generalize to a setting in which the boundary of A has corners. Indeed, for a velocity set F which does not depend on (t,x) and for state constraints taking the form of the intersection of two closed spaces (the simplest case of a boundary with corners), the best distance estimates we can hope for, involving the W1,1, metric on state trajectories, is a super-linear estimate expressed in terms of the h|log(h)| modulus. But, distance estimates involving the h|log(h)| modulus are not in general valid when the velocity set F(.,x) is required merely to be continuous, while not even distance estimates involving the weaker, Hölder modulus hα (with α arbitrarily small) are in general valid, when F(.,x) is allowed to be discontinuous. This paper concerns the validity of distance estimates when the velocity set F(t,x) is (t,x)-dependent and satisfy standard hypotheses on the velocity set (linear growth, Lipschitz x-dependence and an inward pointing condition). Hypotheses are identified for the validity of distance estimates, involving both the h|log(h)| and linear moduli, within the framework of control systems described by a controlled dif
  • Journal article
    Arif J, Ray S, Chaudhuri B, 2013,

    Multivariable Self-Tuning Feedback Linearization Controller for Power Oscillation Damping

    , IEEE Transactions on Control Systems Technology, Vol: 22, Pages: 1519-1526, ISSN: 1558-0865

    The objective of this brief is to design ameasurement-based self-tuning controller, which does not rely onaccurate models and deals with nonlinearities in system response.A special form of neural network (NN) model called feedbacklinearizable NN (FLNN) compatible with feedback linearizationtechnique is proposed for representation of nonlinear powersystems behavior. Levenberg–Marquardt (LM) is applied in batchmode to improve the model estimation. A time-varying feedbacklinearization controller (FBLC) is employed in conjunction withthe FLNN–LM estimator to generate the control signal. Validationof the performance of proposed algorithm is done throughthe modeling and simulating both normal and heavy loadingof transmission lines, when the nonlinearities are pronounced.Case studies on a large-scale 16-machine five-area power systemare reported for different power flow scenarios, to prove thesuperiority of proposed scheme against a conventional modelbasedcontroller. A coefficient vector for FBLC is derivedand used online at each time instant, to enhance the dampingperformance of controller.
  • Patent
    Evangelou SA, Arana C, Shabbir W, Shukla Aet al., 2013,

    Method and Apparatus for Power Source Control
  • Journal article
    Lee CK, Chaudhuri NR, Chaudhuri B, Hui SYRet al., 2013,

    Droop Control of Distributed Electric Springs for Stabilizing Future Power Grid

    , IEEE TRANSACTIONS ON SMART GRID, Vol: 4, Pages: 1558-1566, ISSN: 1949-3053
  • Journal article
    Lee CK, Hui SYR, 2013,

    Reduction of Energy Storage Requirements in Future Smart Grid Using Electric Springs

    , IEEE TRANSACTIONS ON SMART GRID, Vol: 4, Pages: 1282-1288, ISSN: 1949-3053
  • Journal article
    Mueller MA, Angeli D, Allgoewer F, 2013,

    Economic model predictive control with self-tuning terminal cost

    , EUROPEAN JOURNAL OF CONTROL, Vol: 19, Pages: 408-416, ISSN: 0947-3580
  • Journal article
    Tahir F, Jaimoukha IM, Tahir F, Jaimoukha IMet al., 2013,

    Causal state-feedback parameterizations in robust model predictive control

    , Automatica, Vol: 49, Pages: 2675-2682

    In this paper, we investigate the problem of nonlinearity (and non-convexity) typically associated with linear state-feedback parameterizations in the Robust Model Predictive Control (RMPC) for uncertain systems. In particular, we propose two tractable approaches to compute an RMPC controller–consisting of both a causal, state-feedback gain and a control-perturbation component–for linear, discrete-time systems involving bounded disturbances and norm-bounded structured model-uncertainties along with hard constraints on the input and state. Both the state-feedback gain and the control-perturbation are explicitly considered as decision variables in the online optimization while avoiding nonlinearity and non-convexity in the formulation. The proposed RMPC controller–computed through LMI optimizations–is responsible for steering the uncertain system state to a terminal invariant set. Numerical examples from the literature demonstrate the advantages of the proposed scheme
  • Journal article
    Astolfi A, 2013,

    The path of control

    , EUROPEAN JOURNAL OF CONTROL, Vol: 19, Pages: 340-340, ISSN: 0947-3580
  • Journal article
    Tan S-C, Lee CK, Hui SYR, 2013,

    General Steady-State Analysis and Control Principle of Electric Springs With Active and Reactive Power Compensations

    , IEEE TRANSACTIONS ON POWER ELECTRONICS, Vol: 28, Pages: 3958-3969, ISSN: 0885-8993
  • Journal article
    Keliris C, Polycarpou MM, Parisini T, 2013,

    A Distributed Fault Detection Filtering Approach for a Class of Interconnected Continuous-Time Nonlinear Systems

    , IEEE TRANSACTIONS ON AUTOMATIC CONTROL, Vol: 58, Pages: 2032-2047, ISSN: 0018-9286
  • Conference paper
    P Kunjumuhammed L, C Pal B, Anaparthi K, F Thornhill Net al., 2013,

    Effect of wind penetration on power system stability
  • Conference paper
    Lot R, Evangelou SA, 2013,

    Lap Time Optimization of a Sports Series Hybrid Electric Vehicle

    , World Congress on Engineering 2013; WCE2013
  • Journal article
    Pinuela M, Mitcheson PD, Lucyszyn S, 2013,

    Ambient RF energy harvesting in urban and semi-urban environments

    , Transactions on Microwave Theory and Techniques, Vol: 61, Pages: 2715-2726, ISSN: 0018-9480
  • Journal article
    Astolfi A, Longhi S, Tornambe A, 2013,

    Special issue on "periodic systems and robust control' dedicated to Osvaldo Maria Grasselli

    , INTERNATIONAL JOURNAL OF CONTROL, Vol: 86, Pages: 1201-1206, ISSN: 0020-7179
  • Conference paper
    Trovato V, Tindemans SH, Strbac G, 2013,

    Controlling the synchronization and payback associated with the provision of frequency services by dynamic demand

    , 22nd International Conference on Electricity Distribution (CIRED 2013)
  • Journal article
    Chaudhuri NR, Chaudhuri B, 2013,

    Considerations Toward Coordinated Control of DFIG-Based Wind Farms

    , IEEE TRANSACTIONS ON POWER DELIVERY, Vol: 28, Pages: 1263-1270, ISSN: 0885-8977
  • Journal article
    Wee T-C, Astolfi A, Ming X, 2013,

    The Design and Control of a Bipedal Robot with Sensory Feedback

    , INTERNATIONAL JOURNAL OF ADVANCED ROBOTIC SYSTEMS, Vol: 10, ISSN: 1729-8814
  • Conference paper
    Fabozzi D, Thornhill NF, Pal BC, 2013,

    Frequency Restoration Reserve Control Scheme with Participation of Industrial Loads

    , Piscataway, NJ, IEEE PES PowerTech Grenoble 2013, Publisher: IEEE

    In order to accommodate larger amounts of renewable energy resources, whose power output is inherently unpredictable, there is an increasing need for frequency control power reserves. Loads are already used to provide replacement reserves, i.e. the slowest kind of reserves, in several power systems. This paper proposes a control scheme for frequency restoration reserves with participation of industrial loads. Frequency restoration reserves are required to change their active power within a time frame of tens of seconds to tens of minutes in response to a regulation signal. Industrial loads in many cases already have the capacity and capability to participate in this service. A mapping of their process constraints to power and energy demand is proposed in order to integrate industrial loads in existing control schemes. The proposed control scheme has been implemented in a 74-bus test system. Dynamic simulations show that industrial loads can be successfully integrated into the power system as frequency restoration reserves.
  • Conference paper
    P Kunjumuhammed L, C Pal B, F Thornhill N, 2013,

    A Test System Model for Stability Studies of UK Power Grid

    , IEEE PES PowerTech Grenoble 2013
  • Journal article
    Ionescu TC, Astolfi A, 2013,

    Families of moment matching based, structure preserving approximations for linear port Hamiltonian systems

    , Automatica, Vol: 49, Pages: 2424-2434, ISSN: 1873-2836

    In this paper we propose a solution to the problem of moment matching with preservation of the port Hamiltonian structure, in the framework of time-domain moment matching. We characterize several families of parameterized port Hamiltonian models that match the moments of a given port Hamiltonian system, at a set of finite interpolation points. We also discuss the problem of Markov parameters matching for linear systems as a moment matching problem for descriptor representations associated with the given system, at zero interpolation points. Solving this problem yields families of parameterized reduced order models that achieve Markov parameter matching. Finally, we apply these results to the port Hamiltonian case, resulting in families of parameterized reduced order port Hamiltonian approximations.
  • Journal article
    Kiskiras J, Jaimoukha IM, Halikias GD, Kiskiras J, Jaimoukha IM, Halikias GD, Kiskiras J, Jaimoukha IM, Halikias GD, Kiskiras J, Jaimoukha IM, Halikias GD, Kiskiras J, Jaimoukha IM, Halikias GDet al., 2013,

    An explicit state-space solution to the one-block super-optimal distance problem

    , Mathematics of Control, Signals and Systems (MCSS), Vol: 25, Pages: 167-196

    An explicit state-space approach is presented for solving the super-optimal Nehari-extension problem. The approach is based on the all-pass dilation technique developed in [JL93] which offers considerable advantages compared to traditional methods relying on a diagonalisation procedure via a Schmidt pair of the Hankel operator associated with the problem. As a result, all derivations presented in this work rely only on simple linear-algebraic arguments. Further, when the simple structure of the one-block problem is taken into account, this approach leads to a detailed and complete state-space analysis which clearly illustrates the structure of the optimal solution and allows for the removal of all technical assumptions (minimality, multiplicity of largest Hankel singular value, positive-definiteness of the solutions of certain Riccati equations) made in previous work [LHG89],[HLG93]. The advantages of the approach are illustrated with a numerical example. Finally, the paper presents a short survey of super-optimization, the various techniques developed for its solution and some of its applications in the area of modern robust control.
  • Journal article
    Praly L, Carnevale D, Astolfi A, 2013,

    Dynamic Versus Static Weighting of Lyapunov Functions

    , IEEE TRANSACTIONS ON AUTOMATIC CONTROL, Vol: 58, Pages: 1557-1561, ISSN: 0018-9286
  • Journal article
    Alawieh A, Ortega R, Pillai H, Astolfi A, Berthelot Eet al., 2013,

    Voltage Regulation of a Boost Converter in Discontinuous Conduction Mode A SIMPLE ROBUST ADAPTIVE FEEDBACK CONTROLLER

    , IEEE CONTROL SYSTEMS MAGAZINE, Vol: 33, Pages: 55-65, ISSN: 1066-033X
  • Journal article
    Hui SY, 2013,

    Planar Wireless Charging Technology for Portable Electronic Products and Qi

    , PROCEEDINGS OF THE IEEE, Vol: 101, Pages: 1290-1301, ISSN: 0018-9219
  • Journal article
    Egea-Alvarez A, Bianchi F, Junyent-Ferre A, Gross G, Gomis-Bellmunt Oet al., 2013,

    Voltage Control of Multiterminal VSC-HVDC Transmission Systems for Offshore Wind Power Plants: Design and Implementation in a Scaled Platform

    , IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, Vol: 60, Pages: 2381-2391, ISSN: 0278-0046
  • Patent
    Trainer DR, Crookes W, Green TC, Merlin MMCet al., 2013,

    HVDC Converter Comprising Fullbridge Cells For Handling A DC Side Short Circuit
  • Journal article
    Dzafic I, Gilles M, Jabr RA, Pal BC, Henselmeyer Set al., 2013,

    Real Time Estimation of Loads in Radial and Unsymmetrical Three-Phase Distribution Networks

    , IEEE Transactions on Power Systems, Vol: 28, Pages: 4839-4848, ISSN: 0885-8950

    This paper presents a load estimator for large scale asymmetric distribution networks. It is based on iterating between 1) a weighted least squares (WLS) estimator that attempts to adjust the forecasted load group values to the telemetered measurements and 2) a three-phase load flow employing the Fortescue transformation. The WLS estimation phase explicitly handles Y- and $Delta$-connected unbalanced loads and area losses; it can also identify bad measurements based on the estimated load scaling factors. Numerical results show that the proposed load estimator is superior to conventional load allocation based on current balancing, and that its performance is commensurate with the requirements of real-time applications on unsymmetrical radial distribution networks having up to one million nodes.
  • Journal article
    Pinuela M, Yates DC, Lucyszyn S, Mitcheson PDet al., 2013,

    Maximizing DC-to-Load Efficiency for Inductive Power Transfer

    , IEEE Transactions on Power Electronics, Vol: 28, Pages: 2437-2447, ISSN: 0885-8993

    Inductive Power Transfer (IPT) systems for transmitting tens to hundreds of watts have been reported for almost a decade. Most of the work has concentrated on the optimization of the link efficiency and have not taken into account the efficiency of the driver. Class-E amplifiers have been identified as ideal drivers for IPT applications, but their power handling capabilityat tens of MHz has been a crucial limiting factor, since the load and inductor characteristics are set by the requirements of the resonant inductive system. The frequency limitation of the driver restricts the unloaded Q factor of the coils and thus the link efficiency. With a suitable driver, copper coilunloaded Q factors of over 1,000 can be achieved in the low MHz region, enabling a cost-effective high Q coil assembly. The system presented in this paper alleviates the use of heavy andexpensive field-shaping techniques by presenting an efficient IPT system capable of transmitting energy with a dc-to-load efficiency above 77% at 6 MHz across a distance of 30 cm. To the authorsknowledge this is the highest dc-to-load efficiency achieved for an IPT system without introducing restrictive coupling factor enhancement techniques.
  • Journal article
    Pin G, Filippo M, Pellegrino FA, Fenu G, Parisini Tet al., 2013,

    Approximate model predictive control laws for constrained nonlinear discrete-time systems: analysis and offline design

    , INTERNATIONAL JOURNAL OF CONTROL, Vol: 86, Pages: 804-820, ISSN: 0020-7179

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