1. A Novel Controller Design for Hybrid Switched Capacitor DC-DC

Converters. -------IEEE SEP 2009

This paper appears in:  Industrial Electronics, IEEE Transactions on Issue Date :  March 2010 Volume :  57 ,  Issue:3 On page(s): 926 - 934 ISSN :  0278-0046 INSPEC Accession Number: 11119929 Digital Object Identifier :  10.1109/TIE.2009.2032196 Date of Publication :   21 September 2009 Date of Current Version :   08 February 2010 Sponsored by :   IEEE Industrial Electronics Society

Abstract

This paper presents the analysis and novel controller design for a hybrid switched-capacitor bidirectional dc/dc converter. Features of voltage step-down, step-up, and bidirectional power flow are integrated into a single circuit. The novel control strategy enables simpler dynamics compared to a standard buck converter with an input filter, good regulation capability, low electromagnetic interference, lower source current ripple, ease of control, and continuous input current waveform in both modes of operation (buck and boost modes).

2 Controller Design for Two Inductor Boost Converter or Two-Loop

Control of Power Converters

3 Performance Evaluation of Bridgeless PFC Boost Rectifiers –IEEE

MARCH-2007

This paper appears in:  Applied Power Electronics Conference, APEC 2007 - Twenty Second Annual IEEE Issue Date :  Feb. 25 2007-March 1 2007 On page(s): 165 - 171 Location: Anaheim, CA, USA ISSN :  1048-2334 Print ISBN: 1-4244-0713-3 Digital Object Identifier :  10.1109/APEX.2007.357510 Date of Current Version :   07 May 2007

Abstract

In this paper, a systematic review of bridgeless PFC boost rectifiers, also called dual boost PFC rectifiers, is presented. Performance comparison between the conventional PFC boost rectifier and a representative member of the bridgeless PFC boost rectifier family is performed. Design considerations and experimental results in both CCM and DCM/CCM boundary operations are provided.

4 Parallel Power Flow AC/DC Converter with High Input Power Factor

and Tight Output Voltage Regulation for Universal Voltage Application-

IEEE DEC-2006

This paper appears in:  Power Electronics, Drives and Energy Systems, 2006. PEDES '06. International Conference on Issue Date :  12-15 Dec. 2006 On page(s): 1 - 7 Location: New Delhi Print ISBN: 0-7803-9772-X INSPEC Accession Number: 9518023 Digital Object Identifier :  10.1109/PEDES.2006.344388 Date of Current Version :   10 April 2007

Abstract

In this paper, a new parallel-connected single phase power factor correction (PFC) topology using flyback converter in parallel with forward converter is proposed to improve the input power factor with simultaneously output voltage regulation taking consideration of current harmonic norms. Paralleling of converter modules is a well-known technique that is often used in medium-power applications to achieve the desired output power by using smaller size of high frequency transformers and inductors. The proposed approach offers cost effective, compact and efficient AC-DC converter by the use of parallel power processing. Forward converter primarily regulates output voltage with fast dynamic response and it acts as master which processes 60% of the power. Flyback converter with AC/DC PFC stage regulates input current shaping and PFC, and processes the remaining 40% of the power as a slave. This paper presents a design example and circuit analysis for 300 W power supply. A parallel-connected interleaved structure offers smaller passive components, less loss even in continuous conduction inductor current mode, and reduced volt-ampere rating of DC/DC stage converter. MATLAB/Simulink is used for implementation and simulation results show the performance improvement.

5 multiple output ac-dc converters with an internal DC-UPS IEEE-NOV

2OO2

This paper appears in:  Power Electronics Specialists Conference, 2002. pesc 02. 2002 IEEE 33rd Annual Issue Date :  2002 Volume :  3 On page(s): 1095 - 1100 vol.3 Print ISBN: 0-7803-7262-X INSPEC Accession Number: 7432571 Digital Object Identifier :  10.1109/PSEC.2002.1022321 Date of Current Version :   07 November 2002

Abstract

The usual way to avoid a computer shutdown during a mains failure is to connect an AC Uninterruptible Power System (UPS). However, there are other possibilities, as using an internal DC UPS, that is, to allow the topology to operate either from the AC mains or from a battery. A complete design of an AC/DC power supply with an internal DC UPS is presented in this paper. Moreover, the power supply meets all the requirements needed to be used as an ATX PC power supply: multiple outputs, power and voltage ratings, size, protections, etc. A prototype has been fully developed and tested as a PC power supply. The autonomy achieved at full power is around 7 minutes.

6 simulation of three phase voltage source PWM rectifier based on

direct current control-IEEE MAY 2008

This paper appears in:  Image and Signal Processing, 2008. CISP '08. Congress on Issue Date :  27-30 May 2008 Volume :  5 On page(s): 194 - 198 Location: Sanya, China Print ISBN: 978-0-7695-3119-9 Digital Object Identifier :  10.1109/CISP.2008.705 Date of Current Version :   16 July 2008

Abstract

This paper is concerned with the design and simulation of a pulse width modulation (PWM) rectifier for three-phase Permanent Magnetic motor drive. Based on the mathematical model of PWM rectifier, the dual-close-loop engineering design with decoupled feed-forward control is applied in the 3-phase voltage source rectifier. The objective to be reached is to realize unity power factor at the input ac mains and regulate output voltage. The paper presents the MATLAB/SIMULINK simulation model. The results confirm the validity of the model and its control method

2. Design of PWM Rectifier for power factor and voltage regulation

Experimental results of a three-level voltage source inverter with hysteresis-band current control and hybrid PWM-SVM voltage control

This paper appears in:  Power Electronics Specialist Conference, 2003. PESC '03. 2003 IEEE 34th Annual Issue Date :  15-19 June 2003 Volume :  1 On page(s): 183 - 188 vol.1 ISSN :  0275-9306 Print ISBN: 0-7803-7754-0 INSPEC Accession Number: 7809879 Digital Object Identifier :  10.1109/PESC.2003.1218293 Date of Current Version :   04 August 2003

Abstract

This paper presents the experimental results of a diode-clamped three-level inverter used for driving electrical machines. Two different control techniques have been tested for this power converter: a hybrid PWM-SVM voltage control strategy and a double hysteresis-band current control strategy. After checking the good behaviour of these control strategies by simulation results, a small line current THD for a low switching frequency is achieved. Then, a three-level voltage inverter prototype has been developed and both control strategies have been tested upon it. The first one is chosen due to its simplicity, robustness and best ability to filter the current and the second one because a faster and more simple current control can be accomplished. Some simulation results which compare both strategies and some experimental results in the three-level VSI prototype are to be shown in this paper.

Carrier-based PWM-VSI overmodulation strategies: analysis, comparison, and design

This paper appears in:  Power Electronics, IEEE Transactions on Issue Date :  Jul 1998 Volume :  13 ,  Issue:4 On page(s): 674 - 689 ISSN :  0885-8993 References Cited: 21 INSPEC Accession Number: 5982467 Digital Object Identifier :  10.1109/63.704136 Date of Current Version :   06 August 2002 Sponsored by :   IEEE Power Electronics Society

Abstract

In this paper, the overmodulation region voltage-gain characteristics and waveform quality of carrier-based pulsewidth-modulated (PWM) methods are investigated. Through detailed analytical study, voltage-gain characteristics are extracted independent of carrier frequency. The influence of blanking time and minimum pulsewidth (MPW) control on the inverter gain characteristics are studied and shown to be significant. A comparative evaluation of the modulator characteristics reveals the advantageous high-modulation-range characteristics of discontinuous PWM methods and, in particular, the superior overmodulation performance of a discontinuous PWM method. The modulation methods under consideration are tested on a PWM voltage-source inverter (VSI)-fed induction motor drive in the laboratory, and the theoretical results are verified by experiments. Also, a gain linearization technique is presented and experimentally verified. The results of this study are useful in the design, performance prediction and development of high-performance overmodulation strategies for PWM-VSI drives

A 31-level cascade inverter for power applications

This paper appears in:  Industrial Electronics, IEEE Transactions on Issue Date :  Jun 2002 Volume :  49 ,  Issue:3 On page(s): 613 - 617 ISSN :  0278-0046 References Cited: 7 INSPEC Accession Number: 7295799 Digital Object Identifier :  10.1109/TIE.2002.1005388 Date of Current Version :   07 August 2002 Sponsored by :   IEEE Industrial Electronics Society

Abstract

Power inverter modules fed with separate DC voltage sources of voltage ratio 1:2:4:8 are connected to form a cascade multilevel inverter. This new proposal combines the advantages of the static phase-shifter and chain-cell converter concept. Using the same number of power devices as a standard nine-level inverter, the proposed converter operates as a high-power digital-to-analog converter with 31-level resolution. Electrolytic capacitors used in the proposed inverter for providing the DC voltage sources will never be connected in opposite polarity in all cases, thus ensuring high reliability. The proposal has the potential for uninterruptible power supply and flexible AC transmission applications

Modeling and simulation of a permanent magnet brushless DC motor fed by PWM Z-source inverter

This paper appears in:  Electrical Machines and Systems, 2007. ICEMS. International Conference on Issue Date :  8-11 Oct. 2007 On page(s): 834 - 838 Location: Seoul Print ISBN: 978-89-86510-07-2 INSPEC Accession Number: 9826860 Digital Object Identifier :  10.1109/ICEMS.2007.4412201 Date of Current Version :   26 December 2007

Abstract

A novel electric drive system with permanent magnet brushless dc motor (PMBDCM) fed by PWM Z-source inverter is proposed and analyzed in this paper. This drive system provides advantages of both the PMBDCM and Z-source inverter, and can be used in fuel cell system and other adjustable speed drive application. The system configuration, operation principle and control method are presented in detail. And based on the equivalent circuits, the mathematic model of the drive system is established by state-space averaging method. Simulation results validate the desired features as well as the feasibility of the proposed drive system.

3. Model Reference Adaptive Technique for Sensor less Speed

Control of Induction Motor

Sensorless Control of Induction Motor Drives at Very Low and Zero Speeds Using Neural Network Flux Observers

This paper appears in:  Industrial Electronics, IEEE Transactions on Issue Date :  Aug. 2009 Volume :  56 ,  Issue:8 On page(s): 3029 - 3039 ISSN :  0278-0046 INSPEC Accession Number: 10793158 Digital Object Identifier :  10.1109/TIE.2009.2024665 Date of Publication :   09 June 2009 Date of Current Version :   24 July 2009 Sponsored by :   IEEE Industrial Electronics Society

Abstract

A new method is described which considerably improves the performance of rotor flux model reference adaptive system (MRAS)-based sensorless drives in the critical low and zero speed regions of operation. It is applied to a vector-controlled induction motor drive and is experimentally verified. The new technique uses an artificial neural network (NN) as a rotor flux observer to replace the conventional voltage model. This makes the reference model free of pure integration and less sensitive to stator resistance variations. This is a radically different way of applying NNs to MRAS schemes. The data for training the NN are obtained from experimental measurements based on the current model avoiding voltage and flux sensors. This has the advantage of considering all drive nonlinearities. Both open- and closed-loop sensorless operations for the new scheme are investigated and compared with the conventional MRAS speed observer. The experimental results show great improvement in the speed estimation performance for open- and closed-loop operations, including zero speed.

Direct Torque Control –SVM scheme for induction motors fed with a

three level inverter

DTC control schemes for induction motor fed by three-level NPC-VSI using Space Vector Modulation

This paper appears in:  Power Electronics Electrical Drives Automation and Motion (SPEEDAM), 2010 International Symposium on Issue Date :  14-16 June 2010 On page(s): 966 - 971 Location: Pisa Print ISBN: 978-1-4244-4986-6 INSPEC Accession Number: 11466104 Digital Object Identifier :  10.1109/SPEEDAM.2010.5545036 Date of Current Version :   09 August 2010

Abstract

Switching Table based Direct Torque Control (ST-DTC) appears as a promising control technique to be applied to power converters in the industry. However, the ST-DTC presents some drawbacks as non constant switching frequency and high torque ripples. This work proposes a DTC schemes for an induction motor fed by three-level voltage source inverter (VSI), neutral point clamped topology (NPC), with constant switching frequency and reduced torque ripples applying a Space Vector Modulation (SVM) technique. In these methods, the reference voltage vector of the converter is generated by different manner and synthesized each sampling period using the three nearest vectors in stationary plane. Simulation results are presented, showing that using the proposed techniques the switching frequency is fixed and the sampling frequency can be lowered without reducing the quality of the converter behavior and improving the drive performance.

4. Sensor less vector Control of Induction Motors

Experimental performance evaluation for low speed and regenerating operation of sensor-less vector control system of induction motor using observer gain tuning

This paper appears in:  Power Electronics and Motion Control Conference, 2008. EPE-PEMC 2008. 13th Issue Date :  1-3 Sept. 2008 On page(s): 2300 - 2305 Location: Poznan Print ISBN: 978-1-4244-1741-4 INSPEC Accession Number: 10283853 Digital Object Identifier :  10.1109/EPEPEMC.2008.4635606 Date of Current Version :   30 September 2008

Abstract

The design method of adaptive rotor flux observer gain to improve stability at low speed and regenerating mode was proposed in [1]. The method is based on the stability analysis. The stability analysis utilizes the linearized model considering all systems including each control loop. Therefore the proposed method considers the effects of motor constants and control circuit constants. The stability analysis using the transfer function for rotor speed considers the arrangement of pole and zero and the steady state error. The rotor flux observer gain which improves the stability for each operating condition was clarified. Also the real time tuning method of observer gain was proposed in [1]. The validity of the proposed method was confirmed on the simulation using Matlab Simulink and the experiment. Then this paper evaluates the experimental performance for low speed and regenerating operation of sensor-less vector control system of induction motor using observer gain tuning.

5. Fuzzy-logic controlled speed control of brush less dc motor

It is in pdf

6. Fuzzy-logic controlled dc servo motor

Control of the position DC servo motor by fuzzy logic

This paper appears in:  TENCON 2000. Proceedings Issue Date :  2000 Volume :  3 On page(s): 354 - 357 vol.3 Location: Kuala Lumpur Meeting Date :  24 Sep 2000-27 Sep 2000 Print ISBN: 0-7803-6355-8 References Cited: 8 INSPEC Accession Number: 6900337 Digital Object Identifier :  10.1109/TENCON.2000.892288 Date of Current Version :   06 August 2002

Abstract

Presents a fuzzy logic controller for controlling the position of a DC servo motor. The position of the angle location is limited at -π to π radian. The fuzzy inference engine uses angle position from an angular position sensor, and angular velocity. The DC servo motor revolves the circle of axis at the number of revolutions corresponding to the binding voltage. In the revolved axis, there are the moment of inertia and viscous coefficient of friction around its axis and it exerts an influence. The angle is detected by a rotary encoder, and input as angular information of the controlled system to the computer. The applied voltage is determined by computer and sent to the DC servo motor. The results of experiment on a real plant demonstrate that the proposed fuzzy logic controller is sensitive to variation of the reference position

7. Vector control of induction motor

dSPACE implementation of fuzzy logic based vector control of induction motor

This paper appears in:  TENCON 2008 - 2008 IEEE Region 10 Conference Issue Date :  19-21 Nov. 2008 On page(s): 1 - 6 Location: Hyderabad Print ISBN: 978-1-4244-2408-5 INSPEC Accession Number: 10469811 Digital Object Identifier :  10.1109/TENCON.2008.4766502 Date of Current Version :   27 January 2009

Abstract

Vector control of induction motor is an efficient approach to control the speed of induction motor used for industrial drives. Although the vector control is very popular method but there lies difficulty in obtaining an accurate model of induction motor (IM) owing to the variation of induction motor parameters, such as resistance, inductance and time constant. Therefore, to cope up with this uncertainty in the model we used a fuzzy logic based vector control approach to speed control of an induction motor. The focus of the paper is to analyze the real-time implementation issued for realizing a vector control in a laboratory set up of induction motor using dSPACE 1104. This fuzzy logic based vector control scheme has been successfully implemented on a 3 hp induction motor drive in the laboratory and the performances of this controller has been checked with a PID control strategy.

Transient response of DC motor using MATLAB

Transient performance based design optimization of PM brushless DC motor drive speed controller

This paper appears in:  Industrial Electronics, 2005. ISIE 2005. Proceedings of the IEEE International Symposium on Issue Date :  20-23 June 2005 Volume :  3

On page(s): 881 - 886 vol. 3 Print ISBN: 0-7803-8738-4 INSPEC Accession Number: 8733486 Digital Object Identifier :  10.1109/ISIE.2005.1529040 Date of Current Version :   14 November 2005

Abstract

Using standard integral criteria for optimization of speed controller parameters in an electric motor drive result in relatively high overshoot in speed response. Besides that, the speed controller's integral time constant is much higher than maximum drive time constant, which is unfavorable for load torque compensation, in this paper the speed controller parameters of a permanent magnet (PM) brushless direct current (DC) motor drive are obtained in terms of the overshoot in speed response. A dependence of overshoot in speed on speed controller's gain coefficient and integral time constant is derived and graphically presented for easier adoption of the derived results in industrial and research laboratory settings. It is further demonstrated that faster and better load torque compensation is achieved with smaller values of integral time constant and larger values of speed controller gain coefficient A desired speed overshoot is achieved by adding a filter at drive input. Responses on both reference and load torque variations of PM brushless DC motor drive validates the proposed design approach. The results are obtained using Matlab program package for simulation and optimization of the PM brushless DC motor drive.

A novel control strategy for permanent magnet synchronous drive

A novel digital current control strategy for torque ripple reduction in permanent magnet synchronous motor drives

This paper appears in:  Applied Power Electronics Conference and Exposition (APEC), 2010 Twenty-Fifth Annual IEEE Issue Date :  21-25 Feb. 2010 On page(s): 2025 - 2029 Location: Palm Springs, CA ISSN :  1048-2334 Print ISBN: 978-1-4244-4782-4 INSPEC Accession Number: 11204662 Digital Object Identifier :  10.1109/APEC.2010.5433513 Date of Current Version :   18 March 2010

Abstract

Permanent magnet synchronous motors (PMSM) are attractive candidates in various applications because of their high efficiency, high power density, and high position resolution. In some special applications such as military and aerospace, the torque ripple percentage from PMSM has to be maintained in an acceptable level. This objective drives motivations of either optimum design of electrical machines or optimum control of motor drives. On optimum control of motor drives, injecting higher order harmonics has been a dominant technique. This paper presents a novel digital current control strategy to regulate currents with feature of fast dynamic response and easy implementation. Compared with conventional current control loop in vector control of PMSM, a bank of resonant controllers is proposed in parallel connection of PI type controllers. As a result, both fundamental and harmonic components of current can be regulated using high bandwidth digital controllers. Simulation results have verified the control effect of the proposed strategy.

Efficiency optimization control of induction motor using fuzzy logic

Efficiency Optimization of Induction Motor Using a Fuzzy Logic Based Optimum Flux Search Controller

This paper appears in:  Power Electronics, Drives and Energy Systems, 2006. PEDES '06. International Conference on Issue Date :  12-15 Dec. 2006 On page(s): 1 - 6 Location: New Delhi Print ISBN: 0-7803-9772-X INSPEC Accession Number: 9517994 Digital Object Identifier :  10.1109/PEDES.2006.344354 Date of Current Version :   10 April 2007

Abstract

Induction motors are, without any doubt, the most used in industry. Motor drive efficiency optimization is important for two reasons: economic saving and reduction of environmental pollution. In this paper, advantages of using fuzzy logic in steady-state efficiency optimization for induction motor drives are described. Experimental results of a fuzzy logic based optimum flux search controller are presented. There are so many speed control techniques available, like scalar control, vector control, sensor less control etc. Due to coupling effect, the scalar control has inferior performance and vector control is a method of speed control in which both magnitude and phase angle of current can be controlled. In vector control, the presence of speed sensor at shaft decreases the reliability and ruggedness. For transient states, a new original idea is introduced: a fuzzy logic based controller, actuating as a supervisor, is proposed to work with reduced flux levels during transients to optimize efficiency also in dynamic mode. Two different rule tables are designed, for torque transitions and for reference speed changes. With this controller, efficiency can be improved in transients, and also search controller convergence speed is increased. In my work efficiency optimization of induction motor using fuzzy logic controller was carried out using Matlab

Fuzzy Logic based indirect Vector Control of

Induction Motor

Performances of novel fuzzy logic based indirect vector control for induction motor drive

This paper appears in:  Industry Applications Conference, 2000. Conference Record of the 2000 IEEE Issue Date :  2000 Volume :  2 On page(s): 1225 - 1231 vol.2 Location: Rome Meeting Date :  08 Oct 2000-12 Oct 2000 Print ISBN: 0-7803-6401-5 References Cited: 17 INSPEC Accession Number: 6826652 Digital Object Identifier :  10.1109/IAS.2000.881989 Date of Current Version :   06 August 2002

Abstract

This paper presents a novel speed control scheme of an induction motor (IM) using fuzzy logic control. The fuzzy logic controller (FLC) is based on the indirect vector control. The fuzzy logic speed controller is employed in the outer loop. The complete vector control scheme of the IM drive incorporating the FLC is experimentally implemented using a digital signal processor board DS-1102 for the laboratory 1 hp squirrel cage induction motor. The performances of the proposed FLC based IM drive are investigated and compared to those obtained from the conventional proportional integral (PI) controller based drive both theoretically and experimentally at different dynamic operating conditions such as sudden change in command speed, step change in load, etc. The comparative experimental results show that the FLC is more robust and hence found to be a suitable replacement of the conventional PI controller for the high performance industrial drive applications

A T-CONNECTED transformer and three-leg

VSC based DSTATCOM for power quality

improvement

This paper appears in:  Power Electronics, IEEE Transactions on Issue Date :  Nov. 2008 Volume :  23 ,  Issue:6

On page(s): 2710 - 2718 ISSN :  0885-8993 INSPEC Accession Number: 10370061 Digital Object Identifier :  10.1109/TPEL.2008.2004273 Date of Publication :   09 December 2008 Date of Current Version :   22 December 2008 Sponsored by :   IEEE Power Electronics Society

Abstract

In this paper, a new three-phase four-wire distribution static compensator (DSTATCOM) based on a T-connected transformer and a three-leg voltage source converter (VSC) is proposed for power quality improvement. The T-connected transformer connection mitigates the neutral current and the three-leg VSC compensates harmonic current, reactive power, and balances the load. Two single-phase transformers are connected in T-configuration for interfacing to a three-phase four-wire power distribution system and the required rating of the VSC is reduced. The insulated gate bipolar transistor (IGBT) based VSC is supported by a capacitor and is controlled for the required compensation of the load current. The DC bus voltage of the VSC is regulated during varying load conditions. The DSTATCOM is tested for power factor correction and voltage regulation along with neutral current compensation, harmonic elimination, and balancing of linear loads as well as nonlinear loads. The performance of the three-phase four-wire DSTATCOM is validated using MATLAB software with its Simulink and power system blockset toolboxes.

Power Quality Enhancement using Custom

Power Devices (DVR)

The role of custom power products in enhancing power quality at industrial facilities

This paper appears in:  Energy Management and Power Delivery, 1998. Proceedings of EMPD '98. 1998 International Conference on

Issue Date :  3-5 Mar 1998 Volume :  2 On page(s): 507 - 517 vol.2 Meeting Date :  03 Mar 1998-05 Mar 1998 Print ISBN: 0-7803-4495-2 INSPEC Accession Number: 5959881 Digital Object Identifier :  10.1109/EMPD.1998.702726 Date of Current Version :   06 August 2002

Abstract

New technologies, using power electronics-based concepts, have been developed to provide protection for commercial and industrial customers from power quality problems on the electrical distribution system. Known as custom power products, the technologies described in this paper provide protection against sags, swells, voltage flicker, harmonics, and other power quality concerns. The custom power products can increase the availability of sensitive load and reduce costs associated with process interruptions. This paper covers two custom power products that were developed by Westinghouse Electric Corporation under contract to the Electric Power Research Institute (EPRI). The dynamic voltage restorer (DVR), which is a series-connected power electronics based device, quickly compensates for power system sags and swells. The distribution static compensator (DSTATCOM), which is a shunt-connected power electronics-based device, protects the electrical system from a polluting (flicker-producing) load. The DSTATCOM can be used in place of a traditional static VAr compensator and offers many advantages

Transient and dynamic stability enhancement

using Static synchronous series compensator

(SSSC)

Transient Stability Assessment of a Power System with a Static Synchronous Series Compensator

This paper appears in:  Modelling & Simulation, 2007. AMS '07. First Asia International Conference on Issue Date :  27-30 March 2007 On page(s): 26 - 30 Location: Phuket Print ISBN: 0-7695-2845-7 INSPEC Accession Number: 9465089 Digital Object Identifier :  10.1109/AMS.2007.107 Date of Current Version :   10 April 2007

Abstract

Static synchronous series compensator (SSSC) is widely used in power systems to control power of power system by injecting appropriate reactive power into the system. It also has the capability of improving stability and damping by dynamically controlling its reactive power output. This paper presents the energy function of a power system with a SSSC. The proposed energy function is used for transient stability assessment of a power system. This paper develops the control strategy of a SSSC for transient stability and dynamic improvement

A novel dynamic controller for stability enhancement using capacitive series compensator

This paper appears in:  Industrial Electronics, 2004 IEEE International Symposium on Issue Date :  4-7 May 2004 Volume :  2 On page(s): 1111 - 1115 vol. 2 Print ISBN: 0-7803-8304-4 INSPEC Accession Number: 8748350 Digital Object Identifier :  10.1109/ISIE.2004.1571969 Date of Current Version :   10 January 2006

Abstract

This paper presents a novel nonlinear dynamic error driven, error scaled controller for a static series capacitor compensator (SSCC) for enhancing voltage, transient stability and power-transfer capacity. The proposed self adjusting tri-loop tie line controller is based on the speed, terminal voltage and tie line power deviation signals. The proposed study

system is a single machine infinite bus system with a frequency-dependent transmission line model and a local nonlinear-type dynamic load (induction motors). The digital simulation is carried out in time domain as well as in frequency domain by using the special simulation program PSCAD/EMTDC for electromagnetic transient analysis.

Ride through of wind turbines with doubly-fed

induction generator during a voltage dip

Ride Through of Wind Turbines With Doubly Fed Induction Generator Under Symmetrical Voltage Dips

This paper appears in:  Industrial Electronics, IEEE Transactions on Issue Date :  Oct. 2009 Volume :  56 ,  Issue:10 On page(s): 4246 - 4254 ISSN :  0278-0046 INSPEC Accession Number: 10869411 Digital Object Identifier :  10.1109/TIE.2009.2028447 Date of Publication :   03 August 2009 Date of Current Version :   15 September 2009 Sponsored by :   IEEE Industrial Electronics Society

Abstract

This paper deals with the grid fault ride-through capability of doubly fed induction generators. These machines are very sensitive to grid disturbances. To prevent the damages that voltage dips can cause on the converter, most machines are equipped nowadays with a crowbar that short circuits the rotor. However, during the crowbar activation, the rotor converter must be disconnected, hence the power generated with the turbine is no longer controlled. In doing so, the crowbar impedes the wind turbine from carrying out the voltage stabilization required by most new grid codes. This paper proposes a novel control strategy that notably reduces the crowbar activation time. As a result, the control of the turbine might shortly be resumed and the turbine can furthermore supply a reactive power fulfilling the newest grid regulations. Experimental results of a complete system are included, demonstrating the viability of the proposed control.

Damping of Oscillations in interconnected

power systems by IPFC.

The Effect of Interline Power Flow Controller (IPFC) on Damping Inter-area Oscillations in the Interconnected Power Systems

This paper appears in:  Industrial Electronics, 2006 IEEE International Symposium on Issue Date :  9-13 July 2006 Volume :  3 On page(s): 1911 - 1915 Location: Montreal, Que. Print ISBN: 1-4244-0496-7 INSPEC Accession Number: 9210342 Digital Object Identifier :  10.1109/ISIE.2006.295864 Date of Current Version :   29 January 2007

Abstract

The effect of interline power flow controller (IPFC) on damping low frequency oscillations has implied in some papers, but has not investigated in details. This paper investigates the damping control function of an interline power flow controller installed in a power system. For this purpose, single machine-infinite bus model integrated with IPFC is used, and the linearized model is established. Using this model, Phillips-Heffron model of system for steady state digital simulations is derived. In this paper, numerical results with Matlab Simulink toolbox, which show the significant effect of IPFC on damping inter-area oscillations, are represented

The Effect of Interline Power Flow Controller (IPFC) on Damping Interarea Oscillations in the Interconnected Power Systems

This paper appears in:  Universities Power Engineering Conference, 2006. UPEC '06. Proceedings of the 41st International Issue Date :  6-8 Sept. 2006 Volume :  2 On page(s): 769 - 773 Location: Newcastle-upon-Tyne Print ISBN: 978-186135-342-9 INSPEC Accession Number: 9486568 Digital Object Identifier :  10.1109/UPEC.2006.367583 Date of Current Version :   04 June 2007

Abstract

The effect of interline power flow controller (IPFC) on damping low frequency oscillations has implied in some papers, but has not investigated in details. This paper investigates the damping control function of an interline power flow controller installed in a power system. For this purpose, single machine-infinite bus model integrated with IPFC is used, and the linearized model is established. Using this model, Phillips-Heffron model of system for steady state digital simulations is derived. In this paper, numerical results with Matlab Simulink toolbox, which show the significant effect of IPFC on damping inter-area oscillations, are represented

Steady state analysis of UPFC controller

(coding)

Steady-state analysis of a novel UPFC

This paper appears in:  Power Engineering Society General Meeting, 2006. IEEE Issue Date :  0-0 0 On page(s): 6 pp. Location: Montreal, Que. Print ISBN: 1-4244-0493-2 INSPEC Accession Number: 9096730 Digital Object Identifier :  10.1109/PES.2006.1709222 Date of Current Version :   16 October 2006

Abstract

This paper is aimed to the steady state analysis of a novel unified power flow controller (UPFC). A detailed formulation exhibits its inclusion into a Newton-Raphson's power flow program. Simulation results are presented on a 39-buses power system

Power Quality Enhancement using Custom

Power Devices (DSTATCOM)

The role of custom power products in enhancing power quality at industrial facilities

This paper appears in:  Energy Management and Power Delivery, 1998. Proceedings of EMPD '98. 1998 International Conference on Issue Date :  3-5 Mar 1998 Volume :  2 On page(s): 507 - 517 vol.2 Meeting Date :  03 Mar 1998-05 Mar 1998 Print ISBN: 0-7803-4495-2 INSPEC Accession Number: 5959881 Digital Object Identifier :  10.1109/EMPD.1998.702726 Date of Current Version :   06 August 2002

Abstract

New technologies, using power electronics-based concepts, have been developed to provide protection for commercial and industrial customers from power quality problems on the electrical distribution system. Known as custom power products, the technologies described in this paper provide protection against sags, swells, voltage flicker, harmonics, and other power quality concerns. The custom power products can increase the availability of sensitive load and reduce costs associated with process interruptions. This paper covers two custom power products that were developed by Westinghouse Electric Corporation under contract to the Electric Power Research Institute (EPRI). The dynamic voltage restorer (DVR), which is a series-connected power electronics based device, quickly compensates for power system sags and swells. The distribution static compensator (DSTATCOM), which is a shunt-connected power electronics-based device, protects the electrical system from a polluting (flicker-producing) load. The DSTATCOM can be used in place of a traditional static VAr compensator and offers many advantages

Control of Unified Power Flow Controller

(UPFC).

A new approach for the dynamic control of unified power flow controller (UPFC)

This paper appears in:  Power Engineering Society Summer Meeting, 2001. IEEE Issue Date :  2001 Volume :  2 On page(s): 955 - 960 vol.2 Location: Vancouver, BC Meeting Date :  15 Jul 2001-19 Jul 2001 Print ISBN: 0-7803-7173-9 References Cited: 8 INSPEC Accession Number: 7300407 Digital Object Identifier :  10.1109/PESS.2001.970184 Date of Current Version :   06 August 2002

Abstract

This paper presents a new approach for the dynamic control of FACTS apparatus, such as the UPFC and the STATCOM. With the new control strategy, the capabilities of the UPFC can be exploited not only for steady state power flow control but also to improve damping and transient stability assuring a good behavior during contingencies and the protection of the equipment. To achieve optimal UPFC behavior during the dynamic phenomena, the controllable system parameters are determined on-line based on the local instantaneous voltage and current measurements. The strategy is based on the theory of instantaneous powers defined in the positive, negative and zero sequence with real and imaginary components. The power flow calculation should not involve any conventional definitions of power. The Fortescus transformation will be used to conform the relation of the instantaneous active and reactive power (p, q) with the conventional active and reactive power (P3φ, Q3φ). A complete model of the UPFC and the transmission system has been implemented in a digital simulator to demonstrate the versatility of the new control strategy. Interesting results have been obtained, which are presented in this paper

Performance Analysis of Various SRF Methods

in Three Phase Shunt Active Filters

This paper appears in:  Industrial and Information Systems (ICIIS), 2009 International Conference on Issue Date :  28-31 Dec. 2009 On page(s): 442 - 447 Location: Sri Lanka Print ISBN: 978-1-4244-4836-4 INSPEC Accession Number: 11172331 Digital Object Identifier :  10.1109/ICIINFS.2009.5429819 Date of Current Version :   11 March 2010

Abstract

This paper presents different types of synchronous reference frame methods for real time generation of compensating current for harmonic mitigation and reactive power compensation. All the techniques are analyzed mathematically and simulation results are obtained which are being compared in terms of its compensation performance with different parameters under steady state condition. The three techniques analyzed are the Synchronous Reference Frame Theory (SRF), SRF theory without synchronizing circuit like phase lock loop (PLL) also called instantaneous current component theory and finally modified SRF theory. Simulation results are obtained under sinusoidal balanced voltage source balanced load condition. The comparison and effectiveness of all the methods is based on the theoretical analysis and simulation results obtained with MATLAB employing a three phase three wire shunt active filter test system

Classification of power system faults using wavelet transforms and PNN

This paper appears in: Circuits and Systems, 2003. ISCAS '03. Proceedings of the 2003 International Symposium on Issue Date: 25-28 May 2003 Volume: 3 On page(s): III-423 - III-426 vol.3 Print ISBN: 0-7803-7761-3 INSPEC Accession Number: 7769977 Digital Object Identifier: 10.1109/ISCAS.2003.1205046 Date of Current Version: 20 June 2003

Abstract

Automation of power system fault identification using information conveyed by the wavelet analysis of power system transients is proposed. The Probabilistic Neural Network (PNN) for detecting the type of fault is used. The work presented in this paper is focused on identification of simple power system faults. Wavelet Transform (WT) of the transient disturbance caused as a result of the occurrence of a fault is performed. The detail coefficient for each type of simple fault is characteristic in nature. PNN is used for distinguishing the detail coefficients and hence the faults.

Optimal Location of FACTS Devices using Genetic Algorithm (GA)

Optimal location of FACTS devices in power system using Genetic Algorithm

This paper appears in:  Nature & Biologically Inspired Computing, 2009. NaBIC 2009. World Congress on Issue Date :  9-11 Dec. 2009 On page(s): 1034 - 1040 Location: Coimbatore Print ISBN: 978-1-4244-5053-4 INSPEC Accession Number: 11134310 Digital Object Identifier :  10.1109/NABIC.2009.5393860 Date of Current Version :   22 January 2010

Abstract

This paper presents a novel method for optimal location of FACTS devices in a multi machine power system using Genetic Algorithm(GA). Using the proposed method, the location of FACTS controllers, their type and rated values are optimized simultaneously. Among the various FACTS controllers, Static Var controller (SVC), Thyristor Controlled Series Compensator (TCSC) and Unified power Flow Controller (UPFC) are considered. The proposed algorithm is an effective method for finding the optimal choice and location of FACTS controllers and also in minimizing the overall system cost, which comprises of generation cost and investment cost of FACTS controller using GA and conventional Newton- Raphson's power flow method. A MATLAB coding is developed for the simulation. Different operating conditions of the power system are considered. The proposed algorithm has been applied to IEEE 30 bus system.

Economic Load Dispatch using Genetic Algorithm

(GA)

Constrained dynamic economic dispatch by simulated annealing/genetic algorithms

This paper appears in:  Power Industry Computer Applications, 2001. PICA 2001. Innovative Computing for Power - Electric Energy Meets the Market. 22nd IEEE Power Engineering Society International Conference on Issue Date :  2001 On page(s): 207 - 212 Location: Sydney, NSW Meeting Date :  20 May 2001-24 May 2001 Print ISBN: 0-7803-6681-6 References Cited: 9 INSPEC Accession Number: 7106092 Digital Object Identifier :  10.1109/PICA.2001.932349 Date of Current Version :   07 August 2002

Abstract

This paper proposes a genetic algorithm based on simulated annealing solutions (GA-SA) to solve ramp rate constrained dynamic economic dispatch (DED) problems for generating units with non monotonically and monotonically increasing incremental cost (IC) functions. Genetic algorithm (GA) uses a simulated annealing (SA) solution as a base solution in order to reduce the search effort towards the optimal solution. The developed GA-SA algorithm is tested on the generating unit systems in the range of 10 to 40 over the entire dispatch periods. As transmission line losses are included, the solutions are near the optimal solutions of zoom brute force (ZBF) and zoom dynamic programming (ZDP), and are less expensive than those obtained from SA, local search (LS), GA based on merit order loading solutions (GA-MOL) and merit order loading (MOL), thereby leading to substantial fuel cost savings. The proposed GA-SA is effective in solving constrained dynamic economic dispatch in terms of the quality of solution

Harmonic elimination in single phase systems by means of a hybrid series active filter (HSAF)

This paper appears in: Power Electronic & Drive Systems & Technologies Conference (PEDSTC), 2010 1st Issue Date: 17-18 Feb. 2010 On page(s): 423 - 428 Location: Tehran, Iran Print ISBN: 978-1-4244-5944-5 Digital Object Identifier: 10.1109/PEDSTC.2010.5471779 Date of Current Version: 24 May 2010

Abstract

In this paper, a fully-digital-controlled hybrid series active filter (HSAF) for harmonic elimination and reactive power compensation in single phase systems is presented. The HSAF is composed of two single tuned LC filters and a small-rated active filter. Discrete Fourier transformation is used as the control method. Simulation results using MATLAB program shows the effectiveness of the control method. A hybrid series active filter is implemented verifying the accuracy of the control method.