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Using neural networks to optimise gas turbine aero engines

computing & control engineering JOURNAL 1997年第3期8卷 129-135页

作者： Dodd, N Martin, J Neural Solutions Ltd. Cheltenham UK

A technique is presented for controlling gas turbine engines that maintains thrust while minimising fuel consumption A neural network is used to model the engine. Fuel, which is one of the inputs to the model, is decremented and the model used to forward propagate the consequences, one of which is, typically, reduced thrust, Error derivatives to restore the thrust are backpropagated through the network and the error derivatives of the inputs to the model are then used to adjust controllable engine parameters to restore thrust, This iterative technique is continued until the optimum operating point is found, Changes to the engine as a result of temperature change and wear are tracked by updating the neural network engine model online.

关键词： Aerospace engineering computing Aerospace control gas turbine aero engines neural networks forward propagation aerospace control neurocontrollers model reference adaptive control systems gas turbines aerospace engines backpropagation thrust maintenance wear fuel consumption Self-adjusting control systems Optimal control control technology and theory controllable engine parameters control of heat systems control engineering computing iterative technique Aerospace industry temperature change neural network engine model Neural computing techniques Neurocontrol fuel optimal control optimum operating point machine control Aerospace propulsion

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Application of the harmonic control arrays technique to single-phase stand-alone inverters

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IET POWER ELECTRONICS 2016年第7期9卷 1445-1453页

作者： Karbasforooshan, Mohammad-Sadegh Monfared, Mohammad Dogruel, Murat Ferdowsi Univ Mashhad Fac Engn Dept Elect Engn Mashhad Iran Marmara Univ Fac Engn Dept Elect & Elect Engn Istanbul Turkey

This study proposes the adaption of the harmonic control array (HCA) technique to control a single-phase stand-alone inverter system. The HCA method is recently proposed as an efficient scheme to control the systems with periodic references or disturbances. The HCA appropriately adjusts the harmonic components of the control signal to obtain a zero steady-state error. Since the signals and parameters involved in this method are complex valued, a discrete time implementation is presented for applying the method through a digital platform. The design procedure of the controller parameters are also presented by details. To confirm the theoretical achievements, experimental results for the prototype system are presented in this study. The results demonstrate the effectiveness of the proposed control scheme.

关键词： control engineering computing power engineering computing invertors harmonics suppression signal processing harmonic control array technique HCA technique single-phase stand-alone inverter system harmonic component adjustment control signal zero steady-state error discrete time implementation

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NUMERICALLY RELIABLE SOFTWARE FOR control - THE SLICE LIBRARY

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IEE PROCEEDINGS-D control THEORY AND APPLICATIONS 1986年第2期133卷 73-82页

作者： WILLIAMS, TWC School of Computing Kingston Polytechnic Kingston upon Thames UK

The algorithms developed in the control literature have generally been devised from a purely theoretical viewpoint, with no attention being paid to the numerical difficulties which can arise when they are implemented in the finite-precision arithmetic of digital computers. The rounding errors which then result can cause many of these algorithms to produce catastrophically bad results, particularly if the initial data supplied is poorly scaled. The numerical analysis background required to study these problems is given in the paper, and methods available to overcome them described. These are detailed with special reference to the SLICE library of numerically reliable Fortran algorithms for control.

关键词： digital computers numerically reliable FORTRAN algorithms control engineering computing finite-precision arithmetic Digital arithmetic methods digital arithmetic roundoff errors computerised control numerical analysis rounding errors SLICE library

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Performance evaluation of RW-Quadrotor and Bi-Quadrotor for payload delivery

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IET INTELLIGENT TRANSPORT SYSTEMS 2023年第11期17卷 2221-2236页

作者： Dalwadi, Nihal Deb, Dipankar Ozana, Stepan Inst Infrastructure Technol Res & Management Dept Elect Engn Ahmadabad India VSB Tech Univ Ostrava Fac Elect Engn & Comp Sci Dept Cybernet & Biomed Engn Ostrava Czech Republic Inst Infrastructure Technol Res & Management Dept Elect Engn Ahmadabad 380026 India

Payload delivery is one of the many Unmanned Aerial Vehicle (UAV) applications that save time, energy, and human resources. The present simulation study compares rotary-wing quadrotors (RW-Quadrotors) and tail-sitter biplane quadrotors (Bi-Quadrotors) under payload delivery conditions that help to choose the best UAV for the particular mission. A comparative study is performed based on (i) time taken to accomplish the given mission, (ii) trajectory tracking performance, (iii) motor speed throughout the entire flight envelope, and (iv) remains SoC (State of Charge) after the mission. Furthermore, a Backstepping controller (BSC) and an Adaptive Backstepping controller (ABSC) are developed for both UAVs to handle mass changes during flight while Genetic Algorithm (GA) is used for the gain optimization. MATLAB Simulink-based numerical simulation reveals that the Bi-Quadrotor has a lower average rotor speed than the RW-Quadrotor. However, the Bi-Quadrotor's SoC after the mission is higher than the RW-Quadrotor, and it took less time to accomplish the mission. The ABSC designed for RW-Quadrotor and Bi-Quadrotor effectively handles mass change during the mission. However, the BSC controller increases energy consumption for the Bi-Quadrotor in the presence of wind gusts.

关键词： control engineering computing intelligent sensors Internet of Things path planning

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HARMONIC MINIMIZATION IN MICROPROCESSOR controlLED CURRENT FED PWM INVERTER DRIVES

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IEE PROCEEDINGS-B ELECTRIC POWER APPLICATIONS 1987年第1期134卷 25-41页

作者： BOWES, SR BULLOUGH, RI Department of Electrical and Electronic Engineering University of Bristol Bristol UK

New microprocessor-based pulse-width modulation (PWM) control techniques are presented for the current fed inverter (CFI) drive, which minimise the harmonic torque and speed-ripple effects normally associated with low-speed quasi-square-wave operations of CFI drives. It is shown how high-pulse number PWM harmonic elimination current strategies can be developed and used to eliminate substantially greater numbers of harmonics, which hitherto had not been thought a practical possibility. In addition, new PWM harmonic minimisation strategies are presented for the CFI drive, based on the minimisation of a weighted function of stator current harmonic amplitudes. These PWM current minimisation strategies are shown to give superior performance in terms of smoother rotor motion, reduced speed ripple and positional error and can therefore be used to extend the viable range of operation and application of the CFI drive. The complete theoretical development of the new harmonic minimisation PWM current strategies is presented and confirmed using both computed results and experimental results obtained from a previously developed microprocessor-controlled PWM CFI drive. Finally, the PWM control techniques are extended to the ‘duplex’ CFI drive and predicted to give considerable improvements in low-speed performance.

关键词： electric drives minimisation harmonics CFI drive Power convertors and power supplies to apparatus Power engineering computing harmonic torque speed-ripple effects Drives electric current control smoother rotor motion control of electric power systems Current control microprocessor-based pulse-width modulation control invertors current fed PWM inverter drives pulse width modulation harmonic minimisation control engineering computing stator current harmonic amplitudes computerised control

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Auto-tuning scheme for improved current sharing of multiphase DC-DC converters

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IET POWER ELECTRONICS 2012年第9期5卷 1605-1613页

作者： Su, J. -T. Lin, C. -W. Natl Taiwan Univ Dept Elect Engn Taipei 10764 Taiwan

In this study, an auto-tuning scheme is presented to realise simple and accurate calibration, for improved current sharing in multiphase DC-DC converters. The proposed control scheme is based on a look-up table method to automatically tune the pre-stored parameters to obtain the same effect as equal output inductance and direct current resistor (DCR). It ensures that time constant is perfectly matched in a conventional DCR current-sensing technique. The proposed scheme provides a low-cost solution with ease of implementation because it is fully designed using a digital control technique without any external phase compensation elements. The proposed scheme is verified on a two-phase interleaved DC-DC buck converter with a 12-V input and a 1-V, 40-A output. Simulation and experimental results are presented to demonstrate the theoretical analysis.

关键词： current sharing improvement resistors digital control control engineering computing lookup table method multiphase interleaved DC-DC buck converter DCR control of electric power systems table lookup autotuning scheme digital control technique Power electronics, supply and supervisory circuits current sensing technique direct current resistor calibration DC-DC power convertors

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AN EXPERT SYSTEMS-APPROACH TO controlLER-DESIGN

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IEE PROCEEDINGS-D control THEORY AND APPLICATIONS 1990年第6期137卷 367-373页

作者： TEBBUTT, CD Department of Electrical and Electronic Engineering University of Cape Town Cape Town South Africa

An expert system has been used to build an intelligent interface to a recently developed CACSD technique for the design of linear controllers. This combination allows the design to be specified in terms of time and frequency domain constraints on the closed-loop transfer functions, and provides the designer with assistance in formulating a reasonable specification and in dealing with constraint conflicts.

关键词： Expert systems and other AI software and techniques control engineering computing frequency domain constraints frequency-domain synthesis linear systems control system CAD linear controllers expert systems time-domain synthesis closed-loop transfer functions control system analysis and synthesis methods time domain synthesis

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DIGITAL controlLER FOR THYRISTOR CURRENT SOURCE

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IEE PROCEEDINGS-B ELECTRIC POWER APPLICATIONS 1985年第1期132卷 46-52页

作者： LUO, FL JACKSON, RD HILL, RJ Department of Engineering University of Cambridge Cambridge UK

This paper describes the circuits and algorithms used in a microprocessor-controlled AC/DC thyristor convertor to implement a wide-bandwidth closed-loop current source. The convertor consists of two three-phase bridge circuits for four-quadrant operation, with direct digital control using a M6809 microprocessor. The timing pulse generator is linked to the supply frequency via a phase locked loop, making the system insensitive to supply frequency variation. The use of proportional-plus-integral (PI) control algorithms leads to fast responses to step changes in reference input. Results from constant-gain PI controllers are compared in the paper with theoretical responses based on approximate z-transform analysis to obtain optimum parameters for various modes of operation. In addition, results are presented from a simple variable-gain adaptive controller which adjusts the controller parameters depending on the reference change and operating point.

关键词： two term control timing pulse generator Power convertors and power supplies to apparatus AC/DC thyristor convertor direct digital control variable-gain adaptive controller two-term control digital control thyristor applications control of electric power systems M6809 microprocessor three-phase bridge circuits control engineering computing controllers phase locked loop computerised control power convertors wide-bandwidth closed-loop current source supply frequency controllers

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Localisation algorithm with node selection under power constraint in software-defined sensor networks

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IET COMMUNICATIONS 2017年第13期11卷 2035-2041页

作者： Zhu, Yaping Xing, Song Zhang, Yueyue Yan, Feng Shen, Lianfeng Southeast Univ Natl Mobile Commun Res Lab Nanjing Jiangsu Peoples R China Calif State Univ Los Angeles Dept Informat Syst Los Angeles CA 90032 USA Beijing Univ Posts & Telecommun State Key Lab Networking & Switching Technol Beijing Peoples R China

In this study, the authors propose an improved localisation algorithm in the software-defined sensor networks (SDSNs). This algorithm includes a node-selection strategy under the whole network power constraint, based on the software-defined networking (SDN) technique for providing the centralised control of the network. The analogous Cramer-Rao lower bound (A-CRLB) value is derived for each participating node, which represents a fundamental bound on the variance of the position estimator and is used to evaluate the contribution of each node to localisation accuracy. On the basis of A-CRLB values, the most helpful nodes for localisation are selected to maximise the sum of the nodes' contributory values to the localisation accuracy. With the global network knowledge provided by the SDN controller in the SDSN, the node-selection strategy is formulated into a 0-1 programming problem on the premise of power satisfaction of each node. Furthermore, the proposed node-selection -based localisation algorithm is applied to both noncooperative and cooperative localisation scenarios. Simulation results show that the proposed algorithms provide efficient and effective localisation schemes in SDSNs, and can improve the performance in terms of both the selection convergence speed and the localisation accuracy.

关键词： software defined networking control engineering computing wireless sensor networks sensor placement radio direction-finding improved localisation algorithm SDSN technique node-selection strategy whole network power constraint software-defined sensor networking technique A-CRLB analogous Cramer-Rao lower bound 0-1 programming problem cooperative localisation scenario

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Automatic tuning method for the design of supplementary damping controllers for flexible alternating current transmission system devices

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IET GENERATION TRANSMISSION & DISTRIBUTION 2009年第10期3卷 919-929页

作者： de Oliveira, R. V. Kuiava, R. Ramos, R. A. Bretas, N. G. Fed Technol Univ Parana Electromech Engn Dept BR-85503390 Pato Branco PR Brazil Univ Sao Paulo Engn Sch Sao Carlos BR-13566590 Sao Carlos SP Brazil

The design of supplementary damping controllers to mitigate the effects of electromechanical oscillations in power systems is a highly complex and time-consuming process, which requires a significant amount of knowledge from the part of the designer. In this study, the authors propose an automatic technique that takes the burden of tuning the controller parameters away from the power engineer and places it on the computer. Unlike other approaches that do the same based on robust control theories or evolutionary computing techniques, our proposed procedure uses an optimisation algorithm that works over a formulation of the classical tuning problem in terms of bilinear matrix inequalities. Using this formulation, it is possible to apply linear matrix inequality solvers to find a solution to the tuning problem via an iterative process, with the advantage that these solvers are widely available and have well-known convergence properties. The proposed algorithm is applied to tune the parameters of supplementary controllers for thyristor controlled series capacitors placed in the New England/New York benchmark test system, aiming at the improvement of the damping factor of inter-area modes, under several different operating conditions. The results of the linear analysis are validated by non-linear simulation and demonstrate the effectiveness of the proposed procedure.

关键词： electromechanical oscillations control of electric power systems New England-New York benchmark test system Linear algebra (numerical analysis) iterative methods Optimisation techniques flexible AC transmission systems a.c. transmission linear matrix inequalities Power convertors and power supplies to apparatus Power system control linear matrix inequality supplementary damping controller design automatic tuning method damping flexible alternating current transmission system device thyristor controlled series capacitors control system analysis and synthesis methods optimisation algorithm optimisation Interpolation and function approximation (numerical analysis) control system synthesis control engineering computing power engineering computing bilinear matrix inequality iterative process power transmission control Power engineering computing power capacitors thyristor applications power systems

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