New Publications are available for Fuzzy control
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New Publications are available now online for this publication.
Please follow the links to view the publication.A new control method of wind energy in power system
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0124
This paper addresses the new method of controlling wind turbine connected to the grid and presents the approach for implementing wind energy as a distributed generation in a power system. With the aid of a fuzzy controller that regulates the modulation index of PWM inverter in an AC-DC-AC converter, and controllable battery storage connected to DC Bus, output of voltage even during changing wind speed or unbalanced load will remain stable. The control system uses the rule-base defined on the load voltage error of the point of common coupling to determine the instantaneous value of modulation index and battery amount. This technique can give a full flexibility to the grid to provide power from wind turbines, an extra control factor for smart grids and gives this ability to have more control on a system. As a power electronics technique, it also can be used in hybrid PV/Wind energy systems. Performance of the proposed method is illustrated by simulation results. (5 pages)Dynamic voltage restorer based on fuzzy logic control for voltage sag restoration
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0329
Power quality problems such as voltage sags are presently impor tant issues in the industrial field. The dynamic voltage restorer (DVR) is a series compensation device that mitigates voltage sag problems. Due to the nonlinearity of the D VR dynamic character istics, the compensating performance of the D VR is affected much by its control strategy. In this paper, fuzzy logic control is proposed to enhance the compensating performance of the transformer-less D VR. Recently new FL methods have been applied to Custom Pow er Devices, especially for active power filters. The operation of DVR is similar to that of active power filters in that both compensators must respond very fast on the request from abruptly changing ref erence signals. Simulation studies were conducted to show that the proposed fuzzy logic DVR control is very effective in damping the system oscillations and improving the compensating performances compared to the traditional PI control.Application of PI, fuzzy logic and ANN in improvement of power quality using UPQC
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0381
The unified power quality conditioner (UPQC) is being used as a universal active power conditioning device to mitigate both current and voltage harmonics at a distribution side of power system network. This paper emphasis enhancement of power quality by using UPQC with fuzzy logic controller (FLC) and Artificial Neural Network (ANN) controller wrt the conventional proportional-integral (PI) controller. The proposed FLC and ANN are capable of providing good static and dynamic performances compared to PID controller.SHAF for mitigation of current harmonics with p-q and Id-Iq control strategies using both PI and fuzzy controllers
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0389
Control strategies for extracting the three phase reference currents for shunt active power filters are compared, evaluating their performance under different source conditions with PI and Fuzzy Controllers in MATLAB/Simulink environment. The p-q control strategy is unable to yield an adequate solution when source voltages are not ideal. Extensive simulations are carried out with PI controller and also with Fuzzy controller for both p-q and Id-Iq control strategies under different main voltages. Extensive Simulations are carried out with PI as well as fuzzy controller for both p-q and Id-Iq control strategies by considering different voltage conditions and adequate results were presented. On owing Id Iq method with fuzzy logic controller gives away an out-standing performance under any voltage conditions (balanced and un-balanced) over remaining combinations.DSP implementation of fuzzy based power factor Improvement strategy for a dual converter fed drive
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0330
The paper embarks to design a fuzzy based control algorithm through the use of a Digital Signal Processor (DSP) to improve the input power factor of a dual converter fed drive system. Th e strategy is created to ensure that the input current vector forcefully follows the source voltage wave in order to arrive at a significant increase in the fundamental component and lowering of the other harmonic components. The methodology is implemented using a suitable prototype and its performance evaluated experimentally over a vi able range of load powers. The results claim an almost unity input power factor and acceptable values in the total harmonic distortion (THD) of the input current, in addition to regulating the speed of the reversible drive through the entire operating horizon.Study on cooperation of urban traffic control and route guidance based on fuzzy theory
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.1396
In this paper, first, by comparing the relative increment of the traffic flow with the occupancy, we can judge whether the road traffic flow is in the congestion formative stage. Then the road congestion is selected as the input of the fuzzy control, while the green light extension time is selected as the output of the fuzzy control. Next, in order to provide the reasonable input data of the fuzzy control, the detection coil is increased to two in every section under the premise of the data acquisition technology of the SCOOT system. Then the membership functions, the fuzzy control rules, the fuzzy reasoning and the defuzzification are identified by the MATLAB simulation software. Finally, according to the characteristic surface of the input/output between the road congestion and the green light extension time, this control system apparently meets the actual situation. Therefore, before the congestion, the cooperation of the urban traffic flow guidance system and the traffic flow control system is realized by the fuzzy theory.Reactive power control in long transmission line
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0401
Flexible AC transmission system (FACTS) is a technology, which is based on power electronic devices, used to enhance the existing transmission capabilities in order to make the transmission system flexible and independent operation. The FACTS technology is a promising technology to achieve complete deregulation of Power System i.e. Generation, Transmission and Distribution as complete individual units. The loading capability of transmission system can also be enhanced nearer to the thermal limits without affecting the stability. Complete close-loop smooth control of reactive power can be achieved using shunt connected FACTS devices. Static VAR Compensator (SVC) is one of the shunt connected FACTS device, which can be utilized for the purpose of reactive power compensation. Intelligent FACTS devices make them adaptable and hence it is emerging in the present state of art. This paper attempts to de sign and simulate the Fuzzy logic control of firing angle for SVC in order to achieve better, smooth and adaptive control of reactive power. The design, modeling and simulations are carried out for λ/8 Transmission line and the compensation is placed at the receiving end (load end).PI and fuzzy controller based 3-ph 4-wire SHAF for current harmonics compensation using p-q control strategy
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0378
Commencing with incandescent light bulb, every load today creates harmonics. Unfortunately, these loads vary with respect to their amount of harmonic content and response to problems caused by harmonics. Issue of Harmonics are of a greater concern to engineers and building designers because they do more than distort voltage waveforms, they can overheat the building wiring, cause nuisance tripping, overheat transformer units, and cause random end-user equipment failures. Thus power quality has become more and more serious with each passing day. As a result active power filter (APF) gains much more attention due to excellent harmonic compensation. But still the performance of the active filter seems to be in contradictions with different control techniques. The main objective of this paper is to analyse shunt active filter with fuzzy and pi controllers. To carry out the analysis, we consider active and reactive power method (p-q). Extensive simulations were carried out; simulations were performed with balance, unbalanced and non sinusoidal conditions. Simulation results validate the dynamic behaviour of fuzzy logic controller over pi controller.Comparing proportional-resonant and fuzzy-logic controllers for current controlled single-phase grid-connected PWM DC/AC Inverters
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0160
Conventional PI controllers are usually used in single-phase grid-connected dc/ac inverters for photovoltaic plants. These PI controllers suffer from two major drawbacks; steady-state errors in case of sinusoidal reference signals besides their limited disturbance rejection capability. To overcome these shortcomings proportional-resonant (PR) and fuzzy-logic controllers are investigated and then compared with the conventional PI controller. The ability of the PR controller through introducing an infinite gain at a resonance frequency is analysed. The design of the PR-controller is investigated and steps for tuning the controller are given in this work. Moreover, a fuzzy-logic PI(FPI-) controller is also designed and its performance is evaluated with respect to the PIand PR-controllers. A simulation-based analysis is used to investigate the novel comparison between the PR-and FPI-controllers where the controllers' performance is evaluated and compared regarding: transient and steady-state characteristics as well as total harmonic distortion (THD). The analysis showed excellent behaviour of the investigated controllers to overcome the Pi-controller related shortcomings. The FPI-controller showed better transient and disturbance rejection capabilities, while the PR-controller exhibited excellent steady-state characteristics. (6 pages)Fuzzy generalized synchronization between non-smooth-air-gap and smooth-air-gap PMSM chaotic systems with channel delay
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0785
The generalized synchronization problem between non-smooth-air-gap and smooth-air-gap PMSM chaotic systems is studied in this paper. In addition, the channel delay is considered in the realization of the chaotic synchronization. Firstly, the nonsmooth-air-gap PMSM chaotic system and the smooth-air-gap PMSM chaotic system are represented by the T-S fuzzy models without any modeling error. Then, a simple fuzzy state feedback controller is designed based on the parallel distributed compensation technique. By virtue of the definition of lag synchronization and fuzzy control idea, the asymptotical synchronization is realized by choosing appropriate controller gain matrices. Finally, an illustrative example is presented to demonstrate the effectiveness of the proposed fuzzy synchronization method.Intelligence study of control strategy in BGA rework process
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.1324
As one branch of electronic components reuse techniques, research on BGA rework process is significant for ecology and economy. In this paper, one effective control project of heating temperature, reliability detecting of solder joints and automatic adjusting of BGA chip position is proposed, which extremely increases the degree of the artificial intelligence of BGA rework process with using the methods such as Fuzzy-PID theory, Blob analysis algorithm and SIFT feature points extraction and matching algorithm. Put the fuzzy self-tuning PID controller into use in the temperature control system of one electronic assembly equipment, which can achieve the real-time on-line correction of PID parameters and the temperature regulation result that is better than using the conventional PID controller especially in terms of the stability. The information of connected areas in BGA chip image provides basis for automatic reliability detecting of solder joints. SIFT algorithm is able to achieve the match between template image and target image without angle information, so that the precise angle to rotate becomes acquirable.Minimal configuration PI fuzzy gain scheduling speed controller in indirect vector controls scheme
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0151
Paper deals with design of minimal configuration PI fuzzy gain scheduling speed controller in induction motor indirect vector control scheme. Others controllers in control scheme are not of interest. Results gained by simulations and experiments for deferent speed controllers design has been compared. Simulations are carried out via Matlab/Simulink software. Experimental results are gained via dSPACE DS1104 digital control card and experimental model. (6 pages)Fuzzy logic control of brushless doubly fed induction generator
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0085
This paper presents a new fuzzy logic control algorithm to improve the dynamic performance of the brushless doubly fed induction generator (BDFG). Also, an independent control of the active and reactive power is achieved. The system under study consists of a BDFG driven by a voltage source bidirectional converter. The machine model in d-q power winding (PW) synchronously rotating reference frame is formulated in Matlab/Simulink. Both, the active and reactive control paths are implemented using Fuzzy logic controllers (FLC). Meanwhile each path includes two fuzzy logic controllers, one is used for the outer control loop and the other for the inner control loop. The dynamic performance of the BDFG has been tested when the overall system is subjected to a step change in active and reactive power respectively. The simulation results show that the FLC enhance the dynamic response of the overall system compared with conventional proportional plus integral controller. It achieves also independent control of the active and reactive power with reduced cross coupling effect. (7 pages)Conception of robust neural networks for hybrid control of asynchronuous motor drives
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0069
It is well known that the combination between Neural networks and fuzzy controllers are considered as the most efficient approximators of different functions and also proves their capability of controlling nonlinear dynamical systems So, in this paper, the authors introduce a novel technique of control called" hybrid control" which is Based on Feedback Linearization and Field Oriented Control of an Induction Motor, in order to replace the sliding mode controllers (speed and flux ones). In fact, the objectives required by the introduction of neural networks (RANNCs) is to perform the control which is shown by simulation results. (7 pages)Fuzzy control of micro hydro power plants
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0084
The villages have hundred households who had to use costly diesel generator sets to get access to electricity. With setting up of micro hydro power plant, the villagers are able to not only save money but also generate employment opportunities. However, micro hydro generating units are usually isolated from the grid network and require control to maintain both the frequency of the voltage waveform and the scheduled power, for any working conditions, constant. The aim of the present work is to design a fuzzy controller that would manage almost the whole operation of the generating unit. The presented fuzzy controller has three main tasks. First, it regulates the frequency output of the plant in spite of changing user loads. Second, it limits the waste of the available water. Finally, it manages the electricity distribution by dividing the mini network on different departures connected by order of priority. Results obtained by simulation show the controller ability to control the system much better than some controllers proposed in the literature. It guarantees closed loop stability at all operating conditions. The used model for simulation was constructed based on the mathematical equations that summarize the behavior of the plant and was validated based on a micro-hydro power plant prototype. (6 pages)Inverter control using a simplified fuzzy PI controller
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0198
This paper describes the inverter regulation using a simplified Fuzzy PI controller (SFPIC). The proposed controller is a single input Fuzzy with its fuzzification, inferences and defuzzification processes are represented by a piecewise linear control surface. This allows the computation to be faster since the surface can be easily constructed using a look-up table without compromising the performance. For verification purposes, a single-phase inverter prototype is constructed and the proposed control algorithm is implemented. From the results, it was shown that the proposed controller produced a comparable performance as its conventional Fuzzy PI controller, but with a much reduced computation time. (6 pages)A linear time-invariant model for a Vector-controlled two-phase stepping motor
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0149
Recent research on stepping motors concerns intelligent motion control algorithms such as sensorless vector control. Sensorless control is commonly based on a motor model. For stepping motors, this model is highly non-linear, resulting in high computational cost. In this paper it is shown that the motor model can be transformed into a linear model, if the stepping motor is controlled by a vector-control algorithm. The linear model is validated by simulations and sensitivity analysis proves the robustness of the model. (6 pages)An optimal fuzzy-logic controller of a facts device for damping oscillations in power system with wind generation
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1746
An optimal controller for a shunt-connected FACTS device has been developed for enhancing the dynamic performance of a power system with wind power generation in a wide range of transient conditions including wind gusts. The FACTS device considered is based on the Static VAr Compensator (SVC) with fuzzy-logic control which complements the voltage control function to provide system oscillations damping. A constrained-optimization design procedure for determining the optimal values of the linguistic variables for forming the crisp output of the fuzzy-logic controller has been developed. A novel aspect of the design is to establish the nonlinear relationship between the linguistic variables and the power system dynamic performance index (DPI) formed from the variations in wind-turbine induction generator voltage, slip and output active power. The nonlinear relationship is represented by a multilayer feed-forward neural network. The inputs to the neural network are the linguistic variables associated with the controller output, and the neural network output represents the DPI. The objective function defined in terms of the DPI is minimized with respect to the linguistic variables, constrained within their bounds, to give their optimal values. Time-domain simulations illustrate the effectiveness and robustness of the optimized fuzzy logic-controlled SVC in a wide range of operating condition. (6 pages)An intelligent integrated navigation and control solution for an unmanned surface craft
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1686
An adaptive navigation and control algorithm is presented in this paper based on fuzzy logic and optimal control techniques and applied on an unmanned surface vehicle platform. The navigation system consists of an extended Kalman filter with time-varying parameters. Whilst the autopilots include a fuzzy logic based linear quadratic Gaussian controller and a model predictive controller optimized using a genetic algorithm. Both the controllers use the output of the adaptive navigation system as their feedback and therefore creates an integrated system. A multiple waypoint following scenario is considered and tested in real time. Experimental results are shown that demonstrate the efficacy of the proposed system. (6 pages)Fuzzy control of the ram velocity in energy-saving servo injection molding machines
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1514
Since the injection velocity controller for the energy-saving servo drive system is essential, new type energy-saving servo system is becoming one of the hot development directions of injection molding machines. However the nonlinearity and irregular changes of load in the actual injection molding process makes injection speed control complicated. In this paper, an energy-saving servo injection control system using fuzzy control theory based on the re-establishment mathematical model of servo motor-driving fixed pump is presented, including the inputs/outputs of the system and their membership functions and the fuzzy control rule bank. The simulation results according to the parameters of Haitian plastics machinery indicated that the fuzzy controller can effectively reduce injection velocity tracking error. Additionally the system is good-robust compared with the traditional PID controller. (5 pages)Environment modelling in mobile robotics through Takagi-Sugeno fuzzy model
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1701
The modelling of uncertain and dynamic environments is an important and challenging problem in mobile robotics. Nonlinear dynamic systems can be represented as Takagi-Sugeno (T-S) fuzzy models, with linear or affine consequence. This paper proposes a novel method of object tracking in cluttered environments for mobile robots using T-S fuzzy models. The model has been tested on a Patrolbot which tracks a ball using a camera and avoids obstacles using six sonars. (6 pages)A fuzzy control strategy to damp multi mode oscillations of power system considering UPFC
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1780
The growth of the demand for electrical energy leads to loading the transmission system near their limits. Thus, the occurrence of the LFO has increased. Low frequency oscillations (LFO) in power system occur usually because of lack of damping torque to overcome disturbances in power system such as changes in mechanical power. Traditionally, power system stabilizers (PSS) are being used to damp these oscillations. This paper investigates the stability analysis of the application of a unified power flow controller (UPFC) to enhance the damping of low frequency oscillations in a power system, in This paper presents a modified fuzzy control scheme for a UPFC such as supplementary damping controller to enhance damping. In this paper a linearized Heffron-Philips model of a power system with a unified power flow controller is developed. In order for a fuzzy rule based control system to perform well, the fuzzy sets must be carefully designed. A major problem plaguing the effective use of this method is the difficulty of accurately constructing the membership functions .the advantages of this method are their feasibility and increasing rate to damping, to show effectiveness of new fuzzy method in damping oscillation ,the proposed method is compared with a conventional method(lead-lag compensation) is presented. The validity of this method has been confirm by time domain simulation results whit Matlab. (5 pages)Maximum power point tracking for variable-speed fixed-pitch small wind turbines
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.0827
Variable-speed, fixed-pitch wind turbines are required to optimize power output performance without the aerodynamic controls. A wind turbine generator system is operated such that the optimum points of wind rotor curve and electrical generator curve coincide. In order to obtain maximum power output of a wind turbine generator system, it is necessary to drive the wind turbine at an optimal rotor speed for a particular wind speed. In fixed-pitch variable-speed wind turbines, wind-rotor performance is fixed and the restoring torque of the generator needs to be adjusted to maintain optimum rotor speed at a particular wind speed for maximum aerodynamic power output. In turbulent wind environment, control of wind turbine systems to continuously operate at the maximum power points becomes difficult due to fluctuation of wind speeds. Therefore, special emphasis is given to operating at maximum aerodynamic power points of wind rotor. In this paper, the performance of a Fuzzy Logic Maximum Power Point Tracking (MPPT) controller is investigated for applications on variable-speed fixed-pitch small-scale wind turbines. (4 pages)Fuzzy sets- based voltage control strategy for radial distribution systems by genetic algorithm
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.0665
In this paper, new genetic algorithm (GA) by Fuzzy- based and voltage control in a realistic distribution system that is a part of the North Delta Electricity Distribution Company network in Egypt. This system includes tap-changed main transformer, substation switched capacitors and feeders switched capacitors whose operation is to be coordinated. The un-precise linguistic expressions associated to practical operation are treated via fuzzy sets. First, the objective function and constraints are formulated in terms of fuzzy sets. Then, a genetic algorithm technique is adopted to solve the problem to determine the optimal dispatching schedule of the main transformer tap position and capacitors on/off status. Extensive results are discussed while comparing the proposed voltage control strategy versus two others. (4 pages)A new fuzzy logic based adaptation mechanism for MRAS sensorless vector control induction motor drives
http://dl-live.theiet.org/content/conferences/10.1049/cp_20080507
This paper proposes a novel adaptation mechanism to replace the classical PI controller used in model reference adaptive speed estimation schemes which are based on rotor flux. The proposed adaptation mechanism is based on a fuzzy logic strategy. A detailed experimental comparison between the new and conventional schemes is carried out in both open and closed loop sensorless modes of operation when a vector control drive is working at very low speed. Superior performance has been obtained using the new fuzzy logic adaptation mechanism in both modes of operations.Interval type-2 fuzzy logic congestion control of video streaming
http://dl-live.theiet.org/content/conferences/10.1049/cp_20081162
Intelligent congestion control is vital in encoded video streaming of a clip or film, as network traffic volatility requires constant adjustment of the bit-rate. Equation-based solutions to congestion control are prone to fluctuations in the delivery rate and may respond only when packet loss has already occurred, while both fluctuations and packet loss affect the end-user's perception of the delivered video. A type-1 fuzzy logic controller can operate at video display rates and can cope with uncertainties in packet delay measurements but this paper proposes an interval type-2 fuzzy logic congestion controller, as this has the ability to anticipate un-modeled network states, besides potentially reducing training time prior to deployment. The paper demonstrates an order of magnitude improvement in delivered video quality using type-2 fuzzy logic in respect to type-1 logic, when the control inputs are subject to noise, and reduced packet loss compared to an equation-based controller. (8 pages)A heuristic algorithm for fixed train runtime
http://dl-live.theiet.org/content/conferences/10.1049/ic_20080042
This paper proposes a train movement model with fixed runtime that can be employed to find feasible control strategies for a single train along an inter-city railway line. The objective of the model is to minimize arrival delays at each station along railway lines. However, train movement is a typical nonlinear problem for complex running environments and different requirements. A heuristic algorithm is developed to solve the problem in this paper and the simulation results show that the train could overcome the disturbance from train delay and coordinates the operation strategies to sure punctual arrival of trains at the destination. The developed algorithm can also be used to evaluate the running reliability of trains in scheduled timetables.Implementation of model reference adaptive fuzzy controller
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070594
The objective of the model reference adaptive fuzzy control (MRAFC) is to change the rules definition in the direct fuzzy logic controller (FLC) and rule base table according to the comparison between the reference model output signal and system output. The fuzzy inverse model and a knowledge base modifier compose the MRAFC. Because of its improved algorithm, the MRAFC has fast learning features and good tracking characteristics even under severe variations of system parameters. The learning mechanism observes the plant outputs and adjusts the rules in a direct fuzzy controller, so that the overall system behaves like a reference model, which characterizes the desired behavior. In the proposed scheme, the error and error change measured between the motor speed and output of the reference model are applied to the MRAFC. The latter will force the system to behave like the signal reference by modifying the knowledge base of the FLC or by adding an adaptation signal to the fuzzy controller output. In this paper, the MRAFC is applied to a permanent magnet synchronous motor drive (PMSM). High performances and robustness have been achieved by using the MRAFC. This will be illustrated by simulation results and comparisons with other controllers such as PI, classical and adaptive fuzzy controller based on gradient method controllers.Digital simulation of low cost fuzzy logic based four-switch three-phase (PWM) inverter fed induction motor drive
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070642
In this paper performance analysis and MATLAB simulation of a fuzzy logic controller based cost effective drive system of a induction motor for high performance industrial drive systems is presented . In this paper the FLC is used as a speed controller and the motor is fed from a four-switch three-phase (4S3Ph) pulse width-modulation (PWM) inverter instead of a conventional six-switch three-phase (6S3Ph) inverter. This reduces the cost of the inverter, the switching losses, and the complexity of the control algorithms and interface circuits to generate six PWM logic signals. Furthermore, the proposed control approach reduces the computation for real-time implementation. The robustness of the proposed FLC-based 4S3Ph-inverter-fed IM drive is verified by theoretically. A comparison of the proposed 4S3Ph-inverter-fed IM drive with a conventional 6S3Ph inverter system is also made in terms of performance and harmonic analysis of the stator current.ANFIS gain scheduled CSTR with genetic algorithm based PID minimizing integral square error
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070587
In this paper, a new control scheme, the artificial neuro fuzzy inference system (ANFIS) gain scheduled genetic algorithm (GA) based PID is proposed for continuous stirred tank reactor (CSTR). CSTR is a highly nonlinear process that exhibits stability in certain region and instability in some regions. The proposed control scheme implements the characteristics of the genetic algorithm's (GA) global optimization to optimize the PID's three control parameters: k<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">p</sub>, k<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">i</sub>, k<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">d</sub>, to obtain the best control effect by minimizing integral square error online. The GA tuned PID controller parameters are gain scheduled using ANFIS. ANFIS gain- scheduling is a special form of neuro-fuzzy control that uses linguistic rules and fuzzy reasoning to determine the controller parameter transition policy for the dynamic plant subject to large changes in its operating state. Simulation result shows the feasibility of using the proposed controller for the control of the dynamical nonlinear CSTR.Indirect vector controlled induction motor drive with fuzzy logic based intelligent controller
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070639
The indirect vector controlled induction motor (IM) drive involves decoupling of the stator current into torque and flux producing components. This paper proposes the implementation of a fuzzy logic control scheme applied to a two d-q current components model of an induction motor. An intelligent based on fuzzy logic controller is developed with the help of knowledge rule base for efficient control. The performance of fuzzy logic controller is compared with that of the PI controller in terms of the settling time and dynamic response to sudden load changes. The harmonic pattern of the output current is evaluated for both fixed gain proportional integral controller and the fuzzy logic based controller. The performance of the IM drive has been analyzed under steady state and transient conditions. Simulation results of both the controllers are presented for comparison.Fuzzy gain scheduled pole placement based state feedback control of CSTR
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070588
CSTR plays a vital role in almost all the chemical industries. Continuous stirred tank reactor (CSTR) is a highly nonlinear process exhibiting stable and unstable steady state at different regions. Control of CSTR in the complete range is a mind boggling problem. In this paper, a fuzzy scheduled pole placement based state feedback control of CSTR is investigated. The entire region is divided into three regions; low, middle and the high region. The low and the high region have stable steady state and the middle region have unstable steady state. Initially, the gain matrix of the state feedback controller is computed for each region using pole placement technique. Then using fuzzy gain scheduler, the complete controller is formed. The result shows the feasibility of using the proposed controller for the control of CSTR. In this chapter optimal control of CSTR is investigated for the tracking and regulatory problems.Genetically optimized neuro-fuzzy PSS for damping modal oscillations of power system
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070601
An integrated approach of Takagi-Sugeno (TS) fuzzy scheme with a genetic optimization of their parameters has been developed in this paper to design intelligent adaptive controllers for improving the dynamic and transient stability performance of power systems. This concept is applied to power system stabilizer (PSS) connected to a nine bus three machine power system. The rules of the TS-fuzzy scheme are derived from the speed error and their derivatives. Further, to implement this combined scheme only one coefficient in the TS-fuzzy rules needs to be optimized. The optimization of this coefficient as well as the coefficient for auxiliary signal generation is performed through genetic algorithm. The performance of the new controller is evaluated in multimachine power systems subjected to various dynamic and transient disturbances. The new genetic-neuro-fuzzy control scheme exhibits a superior damping performance as well as a greater critical clearing time in comparison to the existing PI and supplementary controller with updating of its parameters through lag-lead compensation. Its simple architecture reduces the computational burden, thereby making it attractive for real-time implementation.A novel approach in automatic control of a hybrid bicycle
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070627
Increased demand for non-polluting mechanized transportation has revived the interest in the use of electric power for personal transportation and also reduced reliance on petrol or diesel driven automobiles. Moreover the fast depletion rate of petroleum & such conventional energy resources have forced mankind to lay much emphasis on the concept of Energy Conservation. This paper makes an effort to divert the attention of mankind more in this direction. A low cost alternative to an automobile is a bicycle. However, the use of bicycles has been limited to very short trips or as a recreational activity. This paper presents a simulation analysis for a Fuzzy Logic Controlled Hybrid Bicycle.PEM fuel cell as energy source using fuzzy logic controller
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070626
A dynamic model of a proton exchange membrane (PEM) fuel cell (FC) has been developed to study its dynamic behaviors along with a fuzzy logic controller (FLC) to control the fuel flow to the reformer. The model can be used to study the dynamic behavior of the system in stand-alone and grid connected mode. The dynamic behavior of the fuel cell system with FLC and PI controller were studied and compared. The dynamic behavior of the system with FLC is found to be more improved as compared to that of the PI controller in terms of response time of the FC system in following the load demand to it. The use of FLC reduces the capacity of storage devices in stand-alone mode to meet the load requirement during transient periods. To meet the power demand set by the user and maintain inverter AC voltage at the desired value PI controllers were used.Optimized operation of SVC for minimal harmonics at distribution level
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070658
Electrical distribution system suffers from various problems like reactive power burden, unbalanced loading, voltage regulation and harmonic distortion. Though DSTATCOMS are ideal solutions for such systems, they are not popular because of the cost and complexity of control involved. Phase wise balanced reactive power compensations are required for fast changing loads needing dynamic power factor correcting devices leading to terminal voltage stabilization. Static Var Compensators (SVCs) remain ideal choice for such loads in practice due to low cost and simple control strategy. These SVCs, while correcting power factor, inject harmonics into the lines causing serious concerns about quality of the distribution line supplies at PCC. In this paper it is proposed to minimize the harmonics injected into the distribution systems by the operation of TSC-TCR type SVC used in conjunction with fast changing loads at LV distribution level. The harmonics are controlled by the optimistic switching of TCR to minimize Total Harmonic Distortion (THD) at PCC and correcting the power factor at the same time. Fuzzy logic system is used to solve this nonlinear problem, giving ranking of a switching pattern used to trigger switches in TCR. The scheme is attractive and can be used at distribution level where load harmonics are within limits.High speed optimised reconfigurable architecture of fuzzy logic controller
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070674
This paper presents a reconfigurable fuzzy logic controller (FLC) with much less hardware than the existing controllers. Pipelining is used in the design to make the FLC fast for high speed real time applications. The FLC is reconfigurable in terms of membership function parameters for antecedent and consequent and fuzzy implication rules. The FLC is implemented in a field programmable gate array (FPGA) and operates at a frequency of 75 MHz.Power system stabilizer using fuzzy logic controller in multimachine power systems
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070599
In general, Power Systems are subjected to wide ranges of transient instability and the dynamic instability. By using fast acting high gain excitation systems the transient stability limit of a synchronous machine has been significantly improved, but impair the dynamic stability. The dynamic instability is damped by using the Power System Stabilizers (PSS). The Power System Stabilizer means a supplementary excitation control which is capable of providing additional damping torque to the rotor angle oscillations of the synchronous machine without affecting its synchronizing torque. The Power System Stabilizer is developed by using the conventional and non conventional controller. In the conventional controller a Phase Lead Compensation technique is used and in the non conventional controller fuzzy set theory is used. The proposed Power System Stabilizer is designed for a Multi-Machine connected to an infinite bus system. The generator speed deviation and acceleration is taken as inputs to the controller. Simulation of Multi-Machine Power Systems with and without using Power System Stabilizers subjected to various disturbances and operating conditions are presented. These simulation results are plotted as a function of time. On comparing simulation results with and without using Power System Stabilizers it is observed that the fuzzy set theory based Power System Stabilizer for Multi-Machine power system has better performance than other.Optimizing the switching angles of SRM using adaptive neuro-fuzzy controller
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070654
This paper presents an application of adaptive neuro-fuzzy controller for optimizing the switching angles of SRM. The proposed adaptive neuro-fuzzy controller has the advantages of expert knowledge of the fuzzy inference system and the learning capability of neural networks. This article is a novel control strategy to improve the power factor of switched reluctance motor drives through optimizing the turn-on angle and the turn-off angle by using the adaptive neuro-fuzzy controller. The simulation results validate the proposed control strategy. The proposed schemes are suitable for both small and large ratings of SRM drives.Design of fuzzy controller for zero current switching quasi resonant buck converter
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070618
Use of soft switching technique, ZCS, is an attempt to substantially reduce switching loss and hence attain higher efficiency at increased frequency. DC to DC quasi resonant converter is a new, high performance power converter and is operated with the technique of soft switching as it is required in many industrial and aerospace applications. It implements zero power consumption operation during switching ON and OFF periods and hence largely reduces the cost and power losses in the converter in order to increase the power density and power transfer efficiency. State space averaging technique is then implemented to develop the transfer function and a novel method namely fuzzy logic is used to improve the performance of the system as it has been developed in detail based on the expert knowledge.A fuzzy logic controlled three-phase neutral-point clamped bidirectional PFC rectifier
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070617
In this paper, a fuzzy logic controlled three-phase neutral-point clamped power factor correction (PFC) bidirectional rectifier is proposed. The fuzzy logic control is based on the linguistic description and does not require a mathematical model of the system. The outer loop PI voltage controller and the inner loop PI current controllers are replaced respectively by the fuzzy PI voltage controller and fuzzy PI current controllers. The performance of the fuzzy logic controller based converter is compared with the conventional PI controller based converter. The fuzzy controller based converter is relatively more robust than the conventional PI controller and gives better dynamic response of the converter. The MATLAB Fuzzy Logic Toolbox is used for implementing the fuzzy logic control scheme. Various simulation results are presented under steady-state and transient conditions to validate the utility of fuzzy logic controllers.Optimized parallel DG with fuzzy logic based on adaptation impedance
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070628
The use of Distributed Generator (DG), or inverter in parallel forms for the feed of a common load has significant role in the increase of feed reliability. In the use of this technology, the imbalance effect and unequal impedance effects of the lines connected between the inverters and load results in circulating currents between inverters. This leads to the limitation of the capacity of the lines and affects the optimum use of the inverter capacity. To get rid of this problem, virtual impedance technique and suitable control methods consisting of active and reactive power determining loops as well as inverter switching reference voltage for the conformity of the impedance lines are used. In order to impose suitable control, the fuzzy control method is used which benefits from better and more real functioning compared to PI classical controller.Fuzzy immune self-regulating PID control for wireless networked control system
http://dl-live.theiet.org/content/conferences/10.1049/cp_20070340
In order to effectively restrain the impact of network delays for wireless networked control systems (WNCS), aiming to time-variant, random and uncertain network delays and controlled plant might be time-variant or nonlinear, as well as Smith predictor models might be imprecise, we propose a novel approach that modified Smith predictor combined with fuzzy immune self-regulating PID control for the WNCS. Because modified Smith predictor does not include network delay models, therefore, it is no need for measuring on line, identifying or estimating network delays, thus it is applicable to some occasions that network delays are larger than one, even tens of sampling periods. Based on IEEE 802.11 b/g (WLAN), the results of simulation experiment show validity of the control scheme and improvement in dynamic performance and robustness of the WNCS.Stability analysis and control synthesis of affine fuzzy systems
http://dl-live.theiet.org/content/conferences/10.1049/cp_20070688
This paper presents an approach to stability analysis and control synthesis of affine fuzzy systems. The analysis is based on quadratic Lyapunov functions. The approach considers the nonlinear offset terms in affine fuzzy systems as non-vanishing perturbations added to the corresponding nominal linear blending systems. The affine fuzzy system is bounded by an ultimate limit if the corresponding linear blending system is exponentially stable. A state feedback controller with an extra term is designed with guaranteed global stability. The ultimate bounds are determined for both the open loop system and the compensated system.A new fuzzy sliding-mode control for MW variable speed-variable pitch wind turbine
http://dl-live.theiet.org/content/conferences/10.1049/cp_20062102
Recently, an increasing number of larger wind turbines (1 MW and up) are being developed with a variable speed-variable pitch control mechanism. The main objective of using a variable speed-variable pitch control strategy is to improve the fast response speed and get maximum energy. But the power generated by wind turbine changes rapidly because of the continuous fluctuation of wind speed and direction. At the same time, wind energy conversion systems are of strong nonlinear characteristics because of many uncertain factors. Based on combined nonlinear sliding-mode control and fuzzy set theory, this paper presents a new kind of state controller to eliminate the steady state error, compensate the nonlinearity and have excellent robustness. (5 pages)Fuzzy excitation control based on wide-area measurements
http://dl-live.theiet.org/content/conferences/10.1049/cp_20062047
In this paper, a fuzzy excitation controller based on wide-are measurement system (WAMS) is built, in which the voltage deviation and its rate are introduced as the input of main-controller, while the deviation and corresponding rate of local generator's frequency and center-of-inertia frequency are acted as the input of the second controller to indicate the global information . The multi-machines system model is firstly set up with MATLAB/PST. Then the digital simulation is conducted to compare the influences of PID excitation controller and fuzzy excitation controller based on WAMS on the transient stability. Results show that applying the fuzzy excitation controller proposed in this paper, the ability to endure serious disturbances can be strengthened and transient stability can be improved. (5 pages)Steady state and transient study of fuzzy controlled load commutated CSI fed induction motor drive
http://dl-live.theiet.org/content/conferences/10.1049/cp_20061910
This paper presents a systematic study for steady state and dynamic performance of fuzzy controlled load commutated CSI fed induction motor drive system. The induction motor has capacitor mounted on its stator terminal to provide load commutation and improved power factor at lower slip. This type of drive system is used especially for large rotating equipments. The dynamic performance characteristic of the load commutated current source inverter (LCCSI) fed induction motor using a linearised model with two feedbacks; one inner current loop and other outer speed loop with two input viz error and change in error and one output fuzzy PI controller are discussed. (6 pages)Realization of close coupling plane double inverted pendulum based on digital motion technology
http://dl-live.theiet.org/content/conferences/10.1049/cp_20061098
Inverted pendulum system is a typical close coupling, nonlinear system with high-rank, multi-variable and serious instability. Aiming at the control problem of Inverted pendulum, the conventional operators have PID operator, pole disposition operator and optimal control operator and so on, most of which are aimed at the single linear or single plane inverted pendulum. Taking into account the control law of the car's displacement, speed, angle, angular-rate and angular acceleration of rod 1 and rod 2 under the input electric voltage, these traditional operators such as LQR (linear quadratic regulator) have an effect of better stability, but sacrifice the robust and transient performance. In view of uncertain factors in pendulum systems, authors design an intelligent controller, i.e. the robust LQR controller for plane two rods inverted pendulum based on the robust optimal control with self-adaptive performance in order to improve the transient state and robustness of the system, then simulate the pendulum system by Matlab. Thus we can get the contrasted response curves of the angle of two rods and car situation according to the two designed methods to compare their advantages and disadvantages. Finally BC 3.1 is adopted to write the digital motion control program and realize the real time control and material object control of the plane two rods inverted pendulum.A heuristic-based design of fuzzy SMES controller for stabilization of interconnected power system
http://dl-live.theiet.org/content/conferences/10.1049/cp_20062146
This paper presents a heuristic-based design of fuzzy logic controller for a superconducting magnetic energy storage (SMES) for stabilization of interconnected power system. Nowadays, a power system becomes complex due to increasing demand in electricity and power system network expansion. Subject to major disturbances, occurrence of power system oscillations is unavoidable. To alleviate the problem, the fuzzy SMES controller is applied in this paper. In particular, SMES has a simultaneous control scheme of active and reactive power. Moreover, the heuristic method, i.e. hybrid tabu search and evolutionary programming (Hybrid TS/EP) is employed to simultaneously optimize control rules and membership functions for fuzzy SMES controller. Consequently, the simulation results and evaluations based on a two-area four-machine power system are carried out to examine the performance and effectiveness of the designed fuzzy SMES controller. (5 pages)Research on excitation controller of synchronous generator based on DSP
http://dl-live.theiet.org/content/conferences/10.1049/cp_20062233
A new excitation controller of synchronous generator is designed basing on special motor control DSP TMS320F2812 and fuzzy PID in this paper. High reliable synchronous signal capture module, phase shift trigger pulse generating module make use of plentiful resource of TMS320F2812, which makes the hardware of the excitation controller simpler and more reliable. PED fuzzy control is employed in software design, which improves the dynamic performance of the excitation controller. (4 pages)