Home > Archives > Latest issue

 

 

International Review of Automatic Control (Theory and Applications) - November  2012 (Vol. 5 N. 6) - Papers

 

 

   

 

 

 


                                                                                               

 

International Review of Automatic Control - Papers

 

go to top   Primary-Side Control for Series-Parallel Loosely Coupling Chargers
         by Yuan-Hsin Chao, Jenn-Jong Shieh

          Vol. 5. n. 6, pp. 728-736

 

Abstract - This paper proposes a primary-side control for a series-parallel loosely systems are determined by considering the maximum output power criterion. Furthermore, in order to impose the operation constraint of minimum volt-ampere (VA) rating of the adapted full bridge inverter, the analytical solutions for the multiple operating frequencies as well as the corresponding feasible conditions are then derived. For enhancing the practical applications, additionally, not only six operation modes but also an integral-type phase luck loop (IPLL) to control secondary output power using primary-side control are further proposed. Finally, two 24V 4.5 Ah lead-acid batteries with the proposed SPLCC is employed with some simulation and experimental results to verify the feasibility of the proposed theory.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Primary-Side Control, Inductive Power Transfer Systems, Maximum Output Power, Minimum Volt-Ampere Rating, Charger, Phase Luck Loop.

 


 

go to top   Voltage and Power Regulation for a Sample Power System Using Heuristics Population Search Based PID Design
         by Ahmed Bensenouci, A. H. Besheer

          Vol. 5. n. 6, pp. 737-748

 

Abstract - In this paper, a solution for driving a single machine infinite bus power system in a robust manner is presented by blending simple feedback linear control theory with heuristic population-based search algorithms. The proposed turbo-generator system is equipped with two decoupled control-loops, namely, the speed/power (governor) and voltage (exciter) controllers. The regulation of the voltage and power is achieved using normal structure of the Automatic Voltage Regulator (AVR) that is assisted by a conventional Power System Stabilizer (PSS). Moreover, rejection for various kinds of electromechanical modes of oscillations in the power grid is guaranteed. The design of power and voltage tunable PID controllers with the conventional PSS is formulated as an optimization problem. The goal of the design is to minimize the demand side variation effect while improving the transient performance of the terminal voltage and power. Using diverse simulation tests - where different kind of variations in load voltage, parameters change and symmetrical three phase short circuit are applied - the feasibility and effectiveness of the proposed controller are illustrated. Moreover, the superiority of the proposed design is further emphasized through a comparative study with Generalized Ziegler Nichols (GZN) based PID designs.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Bacterial Foraging Algorithm, PID Control, A.C. Turbo-Generator System, PSS.

 


 

go to top  Transient Stability Enhancement Using SMES-Based Fault Current Limiter
         by Mehdi Jafari, Ali Vafamehr, Mohammad Reza Alizadeh Pahlavani

          Vol. 5. n. 6, pp. 749-756

 

Abstract - In this paper, transient stability improvement of power system using fault current limiter (FCL) based on superconducting magnetic energy storage (SMES) is proposed. SMES technology is capable to make dc reactors with large values because of its superconducting property. Using such dc reactors in FCL structure can effectively limit the fault current during short circuits in power lines. To show the additional merits of such FCL structure, it is applied to transient stability of single machine infinite bus (SMIB) system with a double circuit transmission line. Analytical analysis including transient stability study is presented. In addition, simulation results using EMTDC/PSCAD software are included to confirm the analytical analysis accuracy.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Fault Current Limiter, Superconducting Magnetic Energy Storage, Transient Stability, Synchronous Generator.

 


 

go to top  Dynamic and Steady-State Operational Performance of Induction and Synchronous Reluctance Motors Powered by PV Generator with MPPT
         by Mohammad S. Widyan, Ghassan. S. Marji, Anas I. Al Tarabsheh

          Vol. 5. n. 6, pp. 757-768

 

Abstract - This paper presents comprehensive dynamic and steady-state performance characteristics of Induction Motor (IM) and Synchronous Reluctance Motor (SRM) powered by Photovoltaic (PV) cells. The PV generator is interfaced to the motors via DC-DC buck-boost switch mode converter, DC-AC switch mode inverter and filter. The duty cycle of the DC-DC converter is controlled such that to track the Maximum Power Point (MPP) of the output characteristics of the PV generator. The DC-AC inverter has fixed modulating and frequency indices. More sinusoidal input voltage to motors is accomplished by placing LC filter across the output terminals of the inverter. The dynamical study comprises successive step changes on the static load coupled to the motors at various solar irradiances. The PV cells are designed such that their maximum power point, at full solar illumination, is at the rated conditions of each motor. The results are compared to the case of supplying the motors by fixed terminal voltage. Furthermore, the dynamical responses of the motors after successive step changes in the solar intensities are obtained. Steady-state output characteristics of PV-powered motors at different solar illuminations are also outlined and compared with the case of supplying them by fixed terminal voltage. The system under investigation is fully modeled including the nonlinearity of the solar-cell generator and all numerical simulations are carried out based on the nonlinear dynamical mathematical model of the complete system.

Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Induction Motor, Synchronous Reluctance Motor, PV Array Design and Characteristics, DC-DC Buck-Boost Switch Mode Converter, Maximum Power Point Tracker.

 


 

go to top  Performance Analysis of New Three Phase Seven Level Asymmetrical Inverter with Hybrid Carrier and Sine 60 Degree Reference
         by Johnson Uthayakumar R., Natarajan S. P., Bensraj R.

          Vol. 5. n. 6, pp. 769-775

 

Abstract - Carrier based Pulse Width Modulation(PWM) techniques have been used widely for switching of multilevel inverters due to their simplicity, flexibility and reduced computational requirements compared to Space Vector Modulation (SVM). A novel carrier based PWM technique for three phase Asymmetrical Multi Level Inverter (AMLI) with sine sixty degree reference is proposed in this paper. The technique is based on the combination of the Control Freedom Degrees (CFD). The combination of inverted sine carrier and triangular carrier is used as hybrid carrier in this work to produce pulses for the power switches used in the proposed three phase seven level AMLI. This paper investigates the potentials of hybrid carrier based cascaded multilevel inverter in the development of medium power AC power supplies with specific emphasis on Power Conditioning Systems (PCS) for alternate sources of energy. The performance of chosen inverter is evaluated through MATLAB-SIMULINK simulation. The performance indices used are Total Harmonic Distortion (THD), RMS value of output voltage and DC bus utilization. It is observed that POD and COPWM relatively provide better DC bus utilization and PDPWM & PODPWM techniques create relatively less distortion for modulation index ma=0.7-1.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Sine 60, PD, POD, APOD, CO, VF, THD, DF.

 


 

go to top  Parity Space Approach Based DC Motorís Fault Detection and Isolation
         by A. Adouni, M. Ben Hamed, L. Sbita

          Vol. 5. n. 6, pp. 776-782

 

Abstract - The main object of this paper is the detection and isolation of sensors and actuatorís DC motor faults. To perform fast diagnosis of these defects, discrete-time parity equations with structural residuals approach has been used. It allows, from a model description, to generate signals that deviate from zeros in case of abnormal operation. These signals are, then, compared to the theoretical residuals in order to make the decision. All the faults are successfully detected and isolated.

Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Analytical Redundancy, DC Motor, Fault Detection, Isolation, Linear System, Parity Space Method, Residual Generation, Diagnosis, Sensor Fault, Actuator Fault.

 


 

go to top  Novel Adaptive Control Scheme for Suppressing Input Current Harmonics in Three-Phase AC Choppers
         by T. Suresh Padmanabhan, M. Sudhakaran, S. Jeevananthan

          Vol. 5. n. 6, pp. 783-789

 

Abstract - Selective harmonic elimination pulse width modulation (SHEPWM) techniques are special kind of optimal PWM techniques. They can generate high quality output waveform through elimination of selected lower order harmonics with a low number of switching transitions. In this paper, a new adaptive current harmonic selective elimination algorithm is proposed for performing harmonic elimination in the supply current of three-phase power converters. The algorithm uses Least Mean Square (LMS) method, which can eliminate any numbers of selected harmonics just by knowing their frequencies and it can also improve the total harmonic distortion (THD) of the line current. This proposed adaptive method is effective in predicting fundamental and harmonic current information from the line current through the self-adjustment of weights of unit sine and cosine components. The predicted harmonic currents are used as the reference signals for selective elimination.

Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: AC Voltage Controller, Least Mean Square (LMS) Algorithm, Selective Harmonic Elimination (SHE).

 


 

go to top  Decentralized Adaptive Sliding Mode Exciter Control of Power Systems
         by S. Benahdouga, D. Boukhetala, F. Boudjema, R. Khenfer, M. Meddad

          Vol. 5. n. 6, pp. 790-797

 

Abstract - The robustness of parameter variations and external disturbances is the major property of sliding mode control system. The aim of this paper is to present a decentralized adaptive sliding mode controller (DASMC) with a nonlinear sliding surface for nonlinear multi-machine power systems model. The combination of adaptive approach and sliding mode controller is used to achieve the decentralization of the control and to exploit the advantage of the sliding mode control. The feedback linearization technique is used in order to handle the nonlinearities of power systems model. Each machine is modeled as an independent uncertain dynamic subsystem where the uncertainty is a disturbance that represents the effects of the rest of the system on that particular machine. This disturbance is expressed as a polynomial function of transient EMF deviation and its parameters are estimated by an adaptive control. A local adaptive sliding mode stabilizer is designed to regulate the machine angle and to stabilize the terminal voltage of each generating unit in the global system under high level external disturbances. This method is illustrated with a three machines-infinite bus power systems. Simulations show that the proposed (DASMEC) provides high-performance in dynamic characteristics and its robustness with regard to external disturbance.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Power System Stability, Feedback Linearization Approach, Sliding Mode Control, Adaptive Sliding Mode Controller.

 


 

go to top  A Novel Control Strategy for Performance Enhancement of Unified Power Quality Conditioner
         by Nikita Hari, Vijayakumar K., S. S. Dash

          Vol. 5. n. 6, pp. 798-803

 

Abstract - The spiraling growth of power electronics based equipments has produced a significant impact on the quality of electric power supply. Conventional power quality mitigation equipment is proving to be inadequate for an increasing number of applications, and this fact has attracted the attention of power engineers to develop dynamic and novel solutions to Power Quality (PQ) problems. This has led to the development of Custom Power Devices (CPD).One modern and very promising CPD that deals with both load current and supply voltage imperfections is the Unified Power Quality Conditioner (UPQC).
This paper investigated the development of UPQC control schemes and algorithms for power quality improvement and implementation of a novel control strategy to enhance the performance of UPQC. The proposed control scheme gives better steady-state and dynamic response. The validity of the proposed control method is verified by means of MATLAB/SIMULINK.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: PQ, CPD, UPQC, Power Quality.

 


 

go to top  Induction Machine Speed and Flux Control, Using Vector-Sliding Mode Control, with Rotor Resistance Adaptation
         by M. Moutchou, A. Abbou, H. Mahmoudi

          Vol. 5. n. 6, pp. 804-814

 

Abstract - This paper presents a vector control of induction machine improved by using a sliding mode control and by using Flux sliding mode observer and a MRAS estimator of rotor resistance, this techniques combination allows to have a good performance in terms of trajectory tracking and robustness towards the parametric uncertainties or parametric variations. The effectiveness and the good performance of this control technique have been proved by simulation results.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Vector Control, Sliding Mode Control, MRAS Observer, Lyapunov Stability, Induction Motor Drive.

 


 

go to top  Comparison of PWM Control Techniques for Cascaded Multilevel Inverter
         by R. Nagarajan, M. Saravanan

          Vol. 5. n. 6, pp. 815-828

 

Abstract - In this paper, three novel pulse width modulation techniques which uses saw tooth carrier waveform, unipolar sine carrier waveform and sine (regular) carrier waveforms are proposed for nine level cascaded inverter. In each carrier waveform different techniques such as phase disposition (PD), inverted phase disposition (IPD), phase opposition disposition (POD) and alternative phase opposition disposition (APOD) are implemented. The fundamental output voltage and harmonics obtained in each method are compared with the output waveform obtained with the triangular carrier waveform. The proposed switching technique enhances the fundamental component of the output voltage and improves total harmonic distortion. The different PWM methodologies adopting the constant switching frequency multicarrier are simulated for a 1KW, 3φ inverter using MATLAB/SIMULINK and the results are verified. The effect of switching frequency on the fundamental output voltage and harmonics are also analyzed.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Multicarrier Sinusoidal Pulse Width Modulation (MC SPWM), Total Harmonic Distortion (THD), Triangular Multicarrier SPWM (TMC SPWM), Saw Tooth Multicarrier SPWM (STMC SPWM), Sine Multicarrier SPWM (SMC SPWM), Unipolar Sine Multicarrier SPWM (USMC SPWM).

 


 

go to top  Overview Control Strategies of Series, Shunt, Series/Shunt FACTS Devices for Three Stability Functions of Power System
         by S. F. Taghizadeh, Younis M. A. A, B. Nikouei, Nadia M. L. Tan, Mekhilef S.

          Vol. 5. n. 6, pp. 829-838

 

Abstract - This paper represents an overview of three types of FACTS devices configurations, categorized by series, shunt and series-shunt consisting of TCSC, SVC and UPFC. Such devices are the most famous Flexible AC Transmission System devices in the world. In the first section features of the devices are introduced briefly, and in the next section control schemes of each are classified and reviewed for three control functions of power system such as steady state stability, transient stability and power oscillation stability. The relevant issues are also considered and discussed.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: FACTS, TCSC, SVC, UPFC, Configuration, Control Function, Control Scheme.

 


 

go to top  Controller Synthesis Using the Novel Fuzzy Petri Net
         by  Mostafa Bayati, Abbas Dideban

          Vol. 5. n. 6, pp. 839-843

 

Abstract - Petri net is a known modeling tool for systematic management and control in dynamic systems. Classical Petri net have been utilized to model a lot of discrete event dynamic systems and for controller design purposes. It is necessary to add new abilities to the classical Petri net, if we want to keep this tool useful in new complex systems. In this paper we proposed Petri net modular modeling concepts and the novel Petri net arithmetic modules, to extend the ability of classical Petri net modeling tools and for controller synthesis purposes. To show the performance of the proposed method, we utilized it to implement a fuzzy Petri net controller in a known case study. To simulate and generate C source code for implementing the designed controller on embedded systems, we developed the software with a graphical user interface in MATLAB environment..
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Petri Net, Fuzzy Petri Net, Petri Net Arithmetic Module, Fuzzy Controller Synthesis.

 


 

go to top  Stability Enhancement of HVDC System Using PI Based STATCOM
         by M. Ramesh, A. Jaya Laxmi

          Vol. 5. n. 6, pp. 844-853

 

Abstract - The necessity to deliver cost effective energy in the power market has become a major concern in this emerging technology era. Therefore, establishing a desired power condition at the given points are best achieved using power controllers such as the well known High Voltage Direct Current (HVDC) and Flexible Alternating Current Transmission System (FACTS) devices. High Voltage Direct Current (HVDC) is used to transmit large amounts of power over long distances or for interconnections between asynchronous grids. The system planner must consider DC alternative in transmission expansion. The factors to be considered are Cost, Technical Performance and Reliability. The static synchronous compensator is one of the FACTS devices which resembles in many respects with a rotating synchronous condenser used for voltage control and reactive power compensation. Several FACTS equipments are readily available or still under development based on the thyristor controlled converters or based on the voltage source inverters (with GTO, IGBT or IGCT switches). All these equipment provide controllability to the AC transmission system by adjusting the transmission parameters, i.e. magnitude and phase angle of bus voltage and transmission line impedances. There are several successful applications of STATCOM for reactive power control, load balancing and voltage control. In recent years, PI control is beginning to receive more attention. The advantages of applying PI control in power systems are apparent. Modem power systems are large, complex, geographically widely distributed and highly nonlinear systems. Moreover, power system operation conditions and topologies are time varying and the disturbances are unforeseeable. The focus of this Paper is to identify the improved transient Stability through control scheme and comprehensive analysis for a Static Synchronous Compensator (STATCOM) on the basis of theory and computer simulation. By Introducing FACTS Controller into HVDC system we can improve the power transmission capability and system stability.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Flexible AC Transmission System (FACTS), High-Voltage DC Transmission (HVDC), STATCOM, Power Transfer Controllability, PI Controller, Faults In HVDC System.

 


 

go to top  Parameter Identification of Permanent Magnet Linear Synchronous Motor Using Hartley Modulating Functions
         by B. Arundhati, K. Alice Mary, M. Suryakalavathi

          Vol. 5. n. 6, pp. 854-859

 

Abstract - High performance control of permanent magnet Linear synchronous machines (PMLSM) requires accurate knowledge of the parameters that describe their mathematical models. This parameter information enables the controller to optimize the drive performance and efficiency, and to react to possible changes in the machine model. Most of the existing approaches to identification of machine parameters involve matching a given input-output behavior with empirical discrete-time approximations such as artificial neural networks, Fuzzy models, model based on wavelets, etc. In this paper a new methodology is presented that is applicable for parameter identification of a iron-cored permanent magnet linear synchronous motor (PMLSM), by defining a set of Hartley modulating functions (HMF)[2]. The advantages of these modulating functions are that the differential equations are reduced to a set of algebraic equations with real coefficients results, the formulations are free from boundary conditions, and the computations can be made using fast algorithms for standard discrete transformation [1]. The effectiveness of the proposed parameter identification algorithm is validated using both simulation and experimental results.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Permanent Magnet Linear Synchronous Motor (PMLSM), Hartley Modulating Functions.

 


 

go to top  Robust Design and Efficiency in Case of Parameters Uncertainties, Disturbances and Noise
         by K. M. Yanev, S. Masupe

          Vol. 5. n. 6, pp. 860-867

 

Abstract - This paper contributes in design and application of a robust controller with two degrees of freedom, capable of suppressing the effects of plantís parameters uncertainties, external disturbances and noise. It also contributes to the analysis of systemís robustness by examining its sensitivity in terms of all variable and disturbing factors. The method of the D-partitioning is applied in the course of design of the robust controller to achieve systemís desired performance and stability. The graphical results of the system sensitivity for each case of parameters uncertainties, disturbances and noise are displaying the efficiency of the designed robust controller. The performance of the robust system is analyzed to demonstrate its improved stability and transient response.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Parameters Uncertainties, Disturbance, Noise, D-Partitioning, Regions of Stability, Robust Control.

 


 

go to top  Numerical Integration Method for Singularly Perturbed Differential-Difference Equations
         by Gemechis File, Y. N. Reddy

          Vol. 5. n. 6, pp. 868-876

 

Abstract - In this paper, we have presented a numerical integration method to solve singularly perturbed differential-difference equations with delay, δ and advance, η parameters that are sufficiently small. First, we have replaced the second order singularly perturbed differential difference equation by asymptotically equivalent first order differential difference equation. Then, Trapezoidal rule and linear interpolation are employed to get three term recurrence relation which is solved easily by Discrete Invariant Imbedding Algorithm. The method is demonstrated by implementing on several model examples by taking various values for the delay parameterδ , advance parameter η and the perturbation parameter ε.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Advance Parameter, Boundary Layer, Delay Parameter, Differential Difference Equations, Singular Perturbations, Trapezoidal Rule.

 


 

go to top  Single Parametric Control of Cascade Brushless DC Motor Drive
         by  Ibrahim Al-Abbas, Mohammad Al Kawaldah, Mohammad Al-Khedher, Rateb Issa

          Vol. 5. n. 6, pp. 877-881

 

Abstract - The proportional plus integral (PI) control is the most widely used algorithm to regulate the armature current and speed of Brushless DC motors in cascade motor drive control systems. However, even when effective tuning methods are employed to satisfy the desired performance, the output overshoot is of higher values. In this paper the PI current controller is replaced with a proportional-integral-derivative (PID) controller to eliminate the overshoot in current loop and then the overshoot in speed loop. Methods of computing PID current controller parameters are derived using Internal Model Control as a function of motor parameters. The transfer function of overall closed loop current is used to determine PI speed controller parameters. Simulation results show the robustness and the effectiveness of the proposed method.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Cascade Control, Current Control, Dc Drive, PID Controller.

 


 

go to top  Parameter Identification of a DC Motor Via Distribution-Based Approach
         by Dorin Sendrescu

          Vol. 5. n. 6, pp. 882-891

 

Abstract - In this paper one presents an algorithm for a DC motor parameters identification from sample data using the distribution approach. While most of the latest methods used in identification utilize a discrete-time model, the distribution method is an alternative approach to directly identify a continuous-time model from discrete-time data. The relation between the state variables is represented by functionals using techniques from distribution theory. Based on these relations, an algorithm for off-line parameter identification is developed. The method is applied to identify the parameters of a real experimental platform.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Parameter Identification, DC Motor, Distributions.

 


 

go to top  Differential Equations of Synchronous Generators Dynamics for Online Assessment within Energy Control Centers
         by Lucian Lupsa-Tataru

          Vol. 5. n. 6, pp. 892-900

 

Abstract - The aim of present investigation is the formulation of a new system of differential equations, in normal form, to describe the saturated synchronous generators dynamics by advancing the d-q axis magnetizing inductances as expressions in terms of d-q axis winding flux linkages only. It will be proven that the representation of magnetizing inductances in this original manner makes it possible to improve the structure of synchronous generators winding flux linkage state-space model with the purpose of online assessment. The selection of the winding flux linkage state-space model is practically justified having in view the model well-known structural simplicity, what makes it suitable for straight implementation within energy control centers. The procedure of representing the d-q axis magnetizing inductances as functions of only winding flux linkages will be carried out in a deductive manner that is without distorting the structural equations of the generalized d-q axis mathematical model of synchronous generators.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Differential Equations, Mathematical Modelling, Nonlinear Systems, Energy Control Center, Synchronous Generators, Magnetizing Inductance.

 


 

go to top  Composite Sliding Mode Control of Induction Motors Using Singular Perturbation Theory
         by A. Mezouar, T. Terras, M. K. Fellah, S. Hadjeri

          Vol. 5. n. 6, pp. 901-910

 

Abstract - In this paper, a composite sliding mode control-observer approach is presented for the induction motor drive. This approach, based on the singular perturbation theory, decomposes the original system into separate slow and fast subsystems and permits that separate slow and fast control and observer can be designed for each subsystem and then combined into a composite control and observer for the original system. The controller design uses the sliding mode technique and is divided in two phases: slow control and fast control so that a final composite control is obtained. In addition and assuming that only the fast states are available; a two time scale sliding mode observer design is proposed for which a stability analysis is easily made. The simulations results validate the performance of the proposed approach.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Induction Motor, Singular Perturbation, Sliding Mode Control, Observer, Stability.

 


 

go to top  Robust Control Design for a Semi-Batch Reactor
         by Frantiöek Gazdoö

          Vol. 5. n. 6, pp. 911-920

 

Abstract - The paper presents control system design for an exothermic semi-batch reactor used for tanning waste recovery. It demonstrates that this highly nonlinear system can be successfully controlled by a relatively simple fixed controller designed robustly. For this purpose the systematic algebraic approach with some useful tools from the robust control theory are fruitfully exploited. The first part presents a simplified mathematical model of the process together with all its parameters and limits. Further in the paper, a complete procedure of control system design including system identification, controller design, robustness analysis and simulation verification are described in detail.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Algebraic Approach, Modelling, Robust Control, Semi-Batch Reactor, Simulation.

 


 

go to top  Effective Detection, Identification and Measurement Strategies of Market Power and Their Comparison
         by  R. Esmaeilzadeh, H. Eskandari, M. Amjadi, M. Farrokhifar

          Vol. 5. n. 6, pp. 921-930

 

Abstract - To cure a market which is infected by market power, or to vaccinate the market against it, first of all market power should be detected then, measured and identified via appropriate tools and indices. Therefore more powerful methods and indices to search created market power or market power potential will result the most appropriate solution to decrease it. In this paper, different methods of analysis, identification and detection are studied and then drawbacks and advantages of each one encountered to different conditions of market power applying are proved.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Market Power, Power Market, Detection Methods, Identification Method.