Publications
Results
- Showing results for:
- Reset all filters
Search results
-
Conference paperKkelis G, Lawson J, Yates DC, et al., 2014,
Integration of a Class-E Low dv/dt Rectifer in a Wireless Power Transfer System
, IEEE Wireless Power Transfer Conference (WPTC), Publisher: IEEE, Pages: 68-71- Cite
- Citations: 3
-
Journal articleAngeli D, Banaji M, Pantea C, 2014,
COMBINATORIAL APPROACHES TO HOPF BIFURCATIONS IN SYSTEMS OF INTERACTING ELEMENTS
, COMMUNICATIONS IN MATHEMATICAL SCIENCES, Vol: 12, Pages: 1101-1133, ISSN: 1539-6746 -
Journal articleAgalgaonkar YP, Pal BC, Jabr RA, 2014,
Distribution voltage control considering the impact of PV generation on tap changers and autonomous regulators
, IEEE Transactions on Power Systems, Vol: 29, Pages: 182-192, ISSN: 0885-8950The uptake of variable megawatts from photovoltaics (PV) challenges distribution system operation. The primary problem is significant voltage rise in the feeder that forces existing voltage control devices such as on-load tap-changers and line voltage regulators to operate continuously. The consequence is the deterioration of the operating life of the voltage control mechanism. Also, conventional non-coordinated reactive power control can result in the operation of the line regulator at its control limit (runaway condition). This paper proposes an optimal reactive power coordination strategy based on the load and irradiance forecast. The objective is to minimize the number of tap operations so as not to reduce the operating life of the tap control mechanism and avoid runaway. The proposed objective is achieved by coordinating various reactive power control options in the distribution network while satisfying constraints such as maximum power point tracking of PV and voltage limits of the feeder. The option of voltage support from PV plant is also considered. The problem is formulated as constrained optimization and solved through the interior point technique. The effectiveness of the approach is demonstrated in a realistic distribution network model.
-
Journal articleDzafic I, Pal BC, Gilles M, et al., 2014,
Generalized π Fortescue Equivalent Admittance Matrix Approach to Power Flow Solution
, IEEE Transactions on Power Systems, Vol: 29, Pages: 193-202, ISSN: 0885-8950This paper develops a generalized admittance matrix approach in Fortescue coordinate system to solve unbalanced/unsymmetrical distribution networks including different number of phases. This generalized Fortescue $pi$ equivalent is defined in this paper for solving the heterogeneous phase, and thus Fortescue, network model. The performance of the approach is demonstrated in different model networks with number of nodes ranging between 168 and 14200. It is found that the current iteration method exploiting the decoupling in admittance matrix in Fortescue coordinate is substantially faster than the typical unbalanced three-phase solution in phase domain. The method has a significant potential for application in real time active power network management.
-
Journal articleKuenzel S, Kunjumuhhamed LP, Pal BC, et al., 2014,
Impact of Wakes on Wind Farm Inertial Response
, IEEE Transactions on Sustainable Energy, Vol: 5, Pages: 237-245, ISSN: 1949-3029 -
Journal articleKiziroglou ME, Wright SW, Toh TT, et al., 2014,
Design and Fabrication of Heat Storage Thermoelectric Harvesting Devices
, Industrial Electronics, IEEE Transactions on, Vol: 61, Pages: 302-309, ISSN: 0278-0046 -
Journal articleLongo S, Kerrigan EC, Constantinides GA, 2014,
Constrained LQR for low-precision data representation
, Automatica, Vol: 50, Pages: 162-168, ISSN: 1873-2836Performing computations with a low-bit number representation results in a faster implementation that uses less silicon, and hence allows an algorithm to be implemented in smaller and cheaper processors without loss of performance. We propose a novel formulation to efficiently exploit the low (or non-standard) precision number representation of some computer architectures when computing the solution to constrained LQR problems, such as those that arise in predictive control. The main idea is to include suitably-defined decision variables in the quadratic program, in addition to the states and the inputs, to allow for smaller roundoff errors in the solver. This enables one to trade off the number of bits used for data representation against speed and/or hardware resources, so that smaller numerical errors can be achieved for the same number of bits (same silicon area). Because of data dependencies, the algorithm complexity, in terms of computation time and hardware resources, does not necessarily increase despite the larger number of decision variables. Examples show that a 10-fold reduction in hardware resources is possible compared to using double precision floating point, without loss of closed-loop performance.
-
Conference paperMoreno FJ, Merlin MMC, Trainer DR, et al., 2014,
Control of an alternate arm converter connected to a star transformer
, Pages: 1-10 -
Conference paperClemow P, Judge P, Chaffey G, et al., 2014,
Lab-scale experimental multilevel modular HVDC converter with temperature controlled cells
, Pages: 1-10 -
Conference paperLuth T, Merlin MMC, Green TC, 2014,
Modular multilevel DC/DC converter architectures for HVDC taps
, Pages: 1-10 -
Conference paperJunyent-Ferre A, Clemow P, Merlin M, et al., 2014,
Operation of HVDC Modular Multilevel Converters under DC pole imbalances
, Pages: 1-10 -
Conference paperMerlin MMC, Green TC, Mitcheson PD, et al., 2014,
Cell capacitor sizing in modular multilevel converters and hybrid topologies
, Pages: 1-10 -
Journal articleToh TT, Wright SW, Kiziroglou ME, et al., 2014,
A dual polarity, cold-starting interface circuit for heat storage energy harvesters
, Sensors and Actuators A: Physical, Vol: 211, Pages: 38-44, ISSN: 0924-4247 -
Conference paperToh TT, Wright SW, Kiziroglou ME, et al., 2014,
Inductive Energy Harvesting for Rotating Sensor Platforms
, ISSN: 1742-6596 -
Conference paperToh TT, Wright SW, Kiziroglou ME, et al., 2014,
Inductive energy harvesting from variable frequency and amplitude aircraft power lines
, ISSN: 1742-6596 -
Journal articleJiang H, Kiziroglou ME, D C Yates, et al., 2014,
A Motion-Powered Piezoelectric Pulse Generator for Wireless Sensing via FM Transmission
, IEEE Internet of Things Journal, Vol: Under Review -
Journal articleSegundo Sevilla FR, Jaimoukha I, Chaudhuri B, et al., 2014,
Fault-tolerant Control Design to Enhance Damping of Inter-areaOscillations in Power Grids
, International Journal in Robust and Nonlinear Control, AcceptedIn this paper, passive and active approaches for the design of fault-tolerant controllers (FTCs) are presented. The FTCs are used to improve the damping of inter-area oscillations in a power grid. The effectiveness of using a combination of local and remote (wide area) feedback signals is first demonstrated. The challenge is then to guarantee a minimum level of dynamic performance following a loss of remote signals. The designs are based on regional pole placement using linear matrix inequalities. First, a passive FTC is proposed. It is shown that the computation of the controller reduces to the solution of bilinear matrix inequalities. An iterative procedure is then used to design the controller. Next, as an alternative to active, time-varying controllers,one for each fault scenario, we propose an approach for the design of a ’minimal switching’ FTC in which only one controller is designed, but where a simple switch is incorporated into the controller structure. A case study in a linear and nonlinear Nordic equivalent system is presented to show that the closed-loop response using a conventional control design could deteriorate the performance or even destabilize the system if the remote signals are lost and to demonstrate the effectiveness of the proposed FTC designs.
-
Conference paperJiang H, Kiziroglou ME, Yates DC, et al., 2014,
A Piezoelectric Pulse Generator and FM Transmission Circuit for Self-Powered BSN Nodes
, Wearable and Implantable Body Sensor Networks (BSN), 2014 11th International Conference on, Publisher: IEEE, Pages: 1-5 -
Journal articleLee CK, Tan SC, Wu FF, et al., 2013,
Use of Hooke's law for stabilizing future smart grid the electric spring concept
, 2013 IEEE Energy Conversion Congress and Exposition, ECCE 2013, Pages: 5253-5257Hooke's law for mechanical springs was developed in the 17th century. Recently, new power electronics devices named electric springs have been developed for providing voltage regulation for distribution networks and allowing the load demand to follow power generation. This paper summarizes recent R&D on electric springs and their potential functions for future smart grid. Electric springs can be associated with electric appliances, forming a new generation of smart loads which can adapt according to the availability of power from renewable energy sources. When massively distributed over the power grid, they could provide highly distributed and robust support for the smart grid, similar to the arrays of mechanical springs supporting a mattress. Thus, the 3-century old Hooke's law in fact provides a powerful solution to solving some key Smart Grid problems in the 21st Century. © 2013 IEEE.
-
Conference paperBottrell N, Green TC, 2013,
An impedance-based method for the detection of over-load and network faults in inverter interfaced distributed generation
An impedance-based method is presented for detecting and differentiating over-load and fault conditions for an inverter-interfaced power generator. When the observed impedance falls below a threshold, current limiting occurs. The impedance-based method, unlike other current limiting strategies, is able to differentiate between an over-load and a network fault. The inverter presented in this paper exports a fixed current for detected over-loads and a higher fixed current for detected faults. An experimental system using a 10 kVA inverter was used to test three cases. The first demonstrates the response of the inverter when the impedance of the load is gradually decreased. The second demonstrates the output of the inverter when a three-phase fault is applied and the third demonstrates the output when a single-phase fault is applied. The impedance-based method is shown to be able to ride-thought the fault and return to normal operation once the fault has been cleared. © 2013 IEEE.
-
Conference paperFalugi P, Mayne DQ, 2013,
Tracking a periodic reference using nonlinear model predictive control
, IEEE Conference on decision and Control, Pages: 5096-6000, ISSN: 0743-1546 -
Conference paperNunna K, Toh TT, Mitcheson PD, et al., 2013,
Sensorless Estimation and Nonlinear Control of a Rotational Energy Harvester
, The 13th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2013) -
ReportSingh AK, Pal BC, 2013,
IEEE PES Task Force on Benchmark Systems for Stability Controls - Report on the 68-Bus, 16-Machine, 5-Area System
, Publisher: IEEE Power and Energy SocietyThis report refers to a small-signal stability study carried over the 68-Bus, 16-Machine, 5-Area Sys-tem and validated on a widely known software package: MATLAB-Simulink (ver. 2012b). The 68-bus sys-tem is a reduced order equivalent of the inter-connected New England test system (NETS) and New York power system (NYPS), with five geographical regions out of which NETS and NYPS are represented by a group of generators whereas, the power import from each of the three other neighboring areas are approxi-mated by equivalent generator models. This report has the objective to show how the simulation of this system must be done using MATLAB in order to get results that are comparable (and exhibit a good match with respect to the electromechanical modes) with the ones obtained using other commercial software packages and presented on the PES Task Force website on Benchmark Systems for Stability Controls (http://www.sel.eesc.usp.br/ieee/).
-
Journal articleMeisel J, Shabbir W, Evangelou SA, 2013,
Evaluation of the through-the-road architecture for plug-in hybrid electric vehicle powertrains
, 2013 IEEE International Electric Vehicle Conference, IEVC 2013This paper investigates the through-the-road (TTR) powertrain architecture and its suitability for plug-in hybrid-electric vehicles (PHEVs) in the passenger vehicle category. The advantages and disadvantages of this architecture with respect to cost, sizing, control and manufacturability are contrasted against those of conventional architectures. The comparison extends into powertrain configurations used in recent commercial vehicles, such as the Toyota Prius and the Chevrolet Volt. The research includes the characterization of the mechanical dynamics and constraint equations of each architecture to quantify the control requirements. It is found that the TTR architecture excels in terms of manufacturability, and its ability to blend the motor and engine torques independently. © 2013 IEEE.
-
Journal articleAunedi M, Kountouriotis P-A, Calderon JEO, et al., 2013,
Economic and Environmental Benefits of Dynamic Demand in Providing Frequency Regulation
, IEEE TRANSACTIONS ON SMART GRID, Vol: 4, Pages: 2036-2048, ISSN: 1949-3053- Author Web Link
- Cite
- Citations: 86
-
Conference paperPudjianto D, Castro M, Strbac G, et al., 2013,
Transmission infrastructure investment requirements in the future European low-carbon electricity system
, ISSN: 2165-4077This paper presents case studies projecting European cross-border electricity transmission infrastructure requirements for a range of future European electricity system scenarios. In calculating the requirements and to attain to the least cost solution, we use a Dynamic System Investment Model. The optimization model minimizes the total investment and operating costs taking into account: (i) the coordination needed between generation and transmission investment; (ii) the need to maintain reliability and feasibility of system operation; and (iii) the applications of load control technology. The model has been used to quantify the transmission requirements for five different European future generation and demand scenarios developed in the 'Infrastructure Roadmap for Energy Networks in Europe', IRENE-40, FP7 project. These include Business-as-Usual, Renewable, DESERTEC, CCS, and the High Efficiency pathways. This paper also presents a discussion on the plausible network technologies to fulfill the requirements and the potential benefits of demand side management in reducing the capacity requirements. © 2013 IEEE.
-
Journal articleKiziroglou ME, Elefsiniotis A, Wright SW, et al., 2013,
Performance of phase change materials for heat storage thermoelectric harvesting
, Applied Physics Letters, Vol: 103, ISSN: 1077-3118Heat storage energy harvesting devices have promise as independent power sources for wireless aircraft sensors. These generate energy from the temperature variation in time during flight. Previously reported devices use the phase change of water for heat storage, hence restricting applicability to instances with ground temperature above 0 °C. Here, we examine the use of alternative phase change materials (PCMs). A recently introduced numerical model is extended to include phase change inhomogeneity, and a PCM characterization method is proposed. A prototype device is presented, and two cases with phase changes at approximately −9.5 °C and +9.5 °C are studied.
-
Conference paperElliott ADT, Dicken J, Miller LM, et al., 2013,
Scheme for improved integration and lifetime for piezoelectric energy harvesters
, IEEE Sensors, Pages: 1-4The power output of piezo harvesters can be significantly increased by using charge modification techniques such as piezoelectric pre-biasing or synchronous switched harvesting, but in order to achieve a significant power gain high Q electrical resonant circuits must be used. For integrated systems with a significant size constraint, or in systems using on-chip inductors, achieving high Q can be difficult. Here we present an improved interface circuit which performs better than all previously presented techniques, especially in cases where the Q-factor of the resonant circuit is low. This has the added advantage of extending the useful life of the harvester because repeated cycling reduces the quality of the piezoelectric film, increasing the series resistance and lowering the electrical Q and the performance. Maximum power extraction by this new circuit is also less sensitive to the supply rail voltage than previously presented implementations, which reduces control power overhead.
-
Journal articlePapadaskalopoulos D, Strbac G, 2013,
Decentralized Participation of Flexible Demand in Electricity Markets-Part I: Market Mechanism
, IEEE TRANSACTIONS ON POWER SYSTEMS, Vol: 28, Pages: 3658-3666, ISSN: 0885-8950- Author Web Link
- Cite
- Citations: 108
-
Journal articlePapadaskalopoulos D, Strbac G, Mancarella P, et al., 2013,
Decentralized Participation of Flexible Demand in Electricity Markets-Part II: Application With Electric Vehicles and Heat Pump Systems
, IEEE TRANSACTIONS ON POWER SYSTEMS, Vol: 28, Pages: 3667-3674, ISSN: 0885-8950- Author Web Link
- Cite
- Citations: 100
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.