http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2013 , Hindawi Publishing Corporation . All rights reserved. Wed, 08 May 2013 14:04:56 +0000 http://www.hindawi.com/journals/ape/2013/625130/ Distributed generation (DG) is deeply changing the existing distribution networks which become very sophisticated and complex incorporating both active and passive equipment. The simplification of their management can be obtained assuming a structure with small networks, namely, microgrids, reproducing, in a smaller scale, the structure of large networks including production, transmission, and distribution of the electrical energy. Power converters in distributed generation systems carry on some different ancillary functions as, for example, grid synchronization, islanding detection, fault ride through, and so on. In view of an optimal utilization of the generated electrical power, fault tolerant operation is to be considered as a suitable ancillary function for the next future. This paper presents a complete modeling of fault tolerant inverters able to simulate the main fault type occurrence and a control algorithm for fault tolerant converters suitable for microgrids. After the model description, formulated in terms of healthy device and leg binary variables, and the illustration of the fault tolerant control strategy, the paper shows how the control preserves power quality when the converter works in the linear range. The effectiveness of the proposed approach and control is shown through computer simulations and experimental results. Antonino O. Di Tommaso, Fabio Genduso, Rosario Miceli, and Giuseppe Ricco Galluzzo Copyright © 2013 Antonino O. Di Tommaso et al. All rights reserved. Wed, 08 May 2013 13:27:49 +0000 http://www.hindawi.com/journals/ape/2013/261959/ Results from the magnetization of an 80 kVA power transformer, using a directly coupled nonfiltered three-phase voltage-source inverter (VSI), are presented. The major benefits of this topology are reduction in switching filter size as well as filter losses. Drawbacks include higher stress on the transformer windings and higher transformer magnetization losses. In this paper, the total magnetization losses are presented for different voltage levels. The transformer has been magnetized with the rated frequency of 50 Hz at various voltage levels. The saturation characteristics as well as the magnetizing resistance are derived as functions of the voltage. These are used as inputs for the simulations. The magnetization losses have been experimentally measured and simulated for three different DC levels. Results from the simulations show good agreement with the experimental results. As expected, the pulsed voltage waveforms generate larger magnetization losses than the corresponding 50 Hz case. The losses are strongly dependent on the DC level. Rickard Ekström, Senad Apelfröjd, and Mats Leijon Copyright © 2013 Rickard Ekström et al. All rights reserved. Thu, 04 Apr 2013 10:39:19 +0000 http://www.hindawi.com/journals/ape/2013/352765/ Different energy sources and converters need to be integrated with each other for extended usage of alternative energy, in order to meet sustained load demands during various weather conditions. The objective of this paper is to associate photovoltaic generators, fuel cells, and electrolysers. Here, to sustain the power demand and solve the energy storage problem, electrical energy can be stored in the form of hydrogen. By using an electrolyser, hydrogen can be generated and stored for future use. The hydrogen produced by the electrolyser using PV power is used in the FC system and acts as an energy buffer. Thus, the effects of reduction and even the absence of the available power from the PV system can be easily tackled. Modeling and simulations are performed using MATLAB/Simulink and SimPowerSystems packages and results are presented to verify the effectiveness of the proposed system. Tourkia Lajnef, Slim Abid, and Anis Ammous Copyright © 2013 Tourkia Lajnef et al. All rights reserved. Thu, 21 Mar 2013 19:25:10 +0000 http://www.hindawi.com/journals/ape/2013/371842/ New hybrid model for efficiency optimization of induction motor drives (IMD) is presented in this paper. It combines two strategies for efficiency optimization: loss model control and search control. Search control technique is used in a steady state of drive and loss model during transient processes. As a result, power and energy losses are reduced, especially when load torque is significant less related to its rated value. Also, this hybrid method gives fast convergence to operating point of minimal power losses and shows negligible sensitivity to motor parameter changes regarding other published optimization strategies. This model is implemented in vector control induction motor drive. Simulations and experimental tests are performed. Results are presented in this paper. Branko Blanuša and Bojan Knezevic Copyright © 2013 Branko Blanuša and Bojan Knezevic. All rights reserved. Tue, 12 Mar 2013 16:26:24 +0000 http://www.hindawi.com/journals/ape/2013/960514/ Conformal antennas and antenna arrays (arrays) have become necessary for vehicular communications where a high degree of aerodynamic drag reduction is needed, like in avionics and ships. However, the necessity to conform to a predefined shape (e.g., of an aircraft’s nose) directly affects antenna performance since it imposes strict constraints to the antenna array’s shape, element spacing, relative signal phase, and so forth. Thereupon, it is necessary to investigate counterintuitive and arbitrary antenna shapes in order to compensate for these constraints. Since there does not exist any available theoretical frame for designing and developing arbitrary-shape antennas in a straightforward manner, we have developed a platform combining a genetic algorithm-based design, optimization suite, and an electromagnetic simulator for designing patch antennas with a shape that is not a priori known (the genetic algorithm optimizes the shape of the patch antenna). The proposed platform is further enhanced by the ability to design and optimize antenna arrays and is intended to be used for the design of a series of antennas including conformal antennas for shipping applications. The flexibility and performance of the proposed platform are demonstrated herein via the design of a high-performance GPS patch antenna. Stelios A. Mitilineos, Symeon K. Symeonidis, Ioannis B. Mpatsis, Dimitrios Iliopoulos, Georgios S. Kliros, Stylianos P. Savaidis, and Nikolaos A. Stathopoulos Copyright © 2013 Stelios A. Mitilineos et al. All rights reserved. Sun, 10 Mar 2013 10:20:55 +0000 http://www.hindawi.com/journals/ape/2013/862734/ The three-phase synchronous reluctance motor (SynRM) is presented as a possible alternative in all-electric ship applications. The basic features of this motor with regard to the other types of motors are shown. The structure of the motor and specifically the structure of its rotor are analyzed, while the basic operating principles are presented and references on commonly used control strategies are made. In this paper, a demonstration of a reluctance motor fed by a voltage source inverter (VSI) takes place. To demonstrate the operation of the motor fed by a VSI, an example using a scalar control method is implemented, where harmonic injection PWM (HIPWM) is used to drive the VSI. Experimental results on a commercially available motor are shown, focusing on the harmonic content of the current. Ioannis Ch. Proimadis, Dionysios V. Spyropoulos, and Epaminondas D. Mitronikas Copyright © 2013 Ioannis Ch. Proimadis et al. All rights reserved. Wed, 06 Mar 2013 17:50:18 +0000 http://www.hindawi.com/journals/ape/2013/831560/ Considerations are held about the specificationin whichthe PV plants have to fulfill so that they can be installed on marine vessels. Initially, a brief description of the typical electrical grid of ships is presented, distinguishing the main parts, reporting the typical electrical magnitudes, and choosing the most preferable installation areas. The technical specifications,in whichthe PV plants have to be compatible with, are fully described. They are determined by the special marine environmental conditions, taking into consideration parameters like wind, humidity, shading, corrosion, and limited installation area. The work is carried out with the presentation of the most popular trends in the field of solar cell types and PV system technologies and their ability to keep up with the aforementioned specifications. Ioannis Kobougias, Emmanuel Tatakis, and John Prousalidis Copyright © 2013 Ioannis Kobougias et al. All rights reserved. Tue, 05 Mar 2013 16:22:08 +0000 http://www.hindawi.com/journals/ape/2013/216870/ Electric propulsion systems are today widely applied in modern ships, including transport ships and warships. The ship of the future will be fully electric, and not only its propulsion system but also all the other services will depend on electric power. The robust and reliable operation of the ship’s power system is essential. In this work, a review on the mechanical and electrical faults of electric machines that are used in electric ships is presented. Dionysios V. Spyropoulos and Epaminondas D. Mitronikas Copyright © 2013 Dionysios V. Spyropoulos and Epaminondas D. Mitronikas. All rights reserved. Sun, 24 Feb 2013 09:55:08 +0000 http://www.hindawi.com/journals/ape/2013/591680/ A growing number of harmonic mitigation techniques are now available including active and passive methods, and the selection of the best-suited technique for a particular case can be a complicated decision-making process. The performance of some of these techniques is largely dependent on system conditions, while others require extensive system analysis to prevent resonance problems and capacitor failure. A classification of the various available harmonic mitigation techniques is presented in this paper aimed at presenting a review of harmonic mitigation methods to researchers, designers, and engineers dealing with power distribution systems. Hussein A. Kazem Copyright © 2013 Hussein A. Kazem. All rights reserved. Tue, 19 Feb 2013 11:32:38 +0000 http://www.hindawi.com/journals/ape/2013/837010/ The impact of the rotor slot number selection on the induction motors is investigated. Firstly, analytical equations will reveal the spatial harmonic index of the air gap magnetic flux density, connected to the geometrical features and the saturation of the induction motor. Then, six motors with different rotor slot numbers are simulated and studied with FEM. The stator is identical in all motors. The motors are examined under time-harmonic analysis at starting and at 1440 rpm. Their electromagnetic characteristics, such as electromagnetic torque, stator current, and magnetic flux density, are extracted and compared to each other. The analysis will reveal that the proper rotor slot number selection has a strong impact on the induction motor performance. Konstantinos N. Gyftakis and Joya Kappatou Copyright © 2013 Konstantinos N. Gyftakis and Joya Kappatou. All rights reserved. Mon, 28 Jan 2013 13:43:02 +0000 http://www.hindawi.com/journals/ape/2013/249146/ The development of the smart grids leads to new challenges on the power electronics equipment and power transformers. The use of power electronic transformer presents several advantages, but new problems related with the application of high frequency voltage and current components come across. Thus, an accurate knowledge of the transformer behavior in a wide frequency range is mandatory. A novel modeling procedure to relate the transformer physical behavior and its frequency response by means of electrical parameters is presented. Its usability is demonstrated by an example where a power transformer is used as filter and voltage reducer in an AC-DC-AC converter. Carlos Gonzalez-Garcia and Jorge Pleite Copyright © 2013 Carlos Gonzalez-Garcia and Jorge Pleite. All rights reserved. Sun, 30 Dec 2012 08:52:16 +0000 http://www.hindawi.com/journals/ape/2012/852024/ This paper presents a MATLAB/Simulink simulation of direct and indirect space vector modulation for matrix converter. Different switching patterns for both direct and indirect methods are simulated and compared. Three criteria are chosen to compare the performance of switching patterns: (1) total harmonic distortion (THD); (2) harmonic spectrum analysis of output voltages; and (3) number of switching in each switching period. Switching strategies are completely implemented using the power library in MATLAB/Simulink environment. Amin Shabanpour, Sasan Gholami, and Ali Reza Seifi Copyright © 2012 Amin Shabanpour et al. All rights reserved. Thu, 27 Dec 2012 16:36:16 +0000 http://www.hindawi.com/journals/ape/2012/176876/ This paper developed an adaptive observer to estimate capacitors voltages of a three-level neutral-point-clamped (NPC) inverter. A robust estimated method using one parameter is proposed, which eliminates the voltages sensors. An averaged modeling of the inverter was used to develop the observer. This kind of modeling allows a good trade-off between simulation cost and precision. Circuit model of the inverter (implemented in Simpower Matlab simulator) associated to the observer algorithm was used to validate the proposed algorithm. Bassem Omri, Kaiçar Ammous, and Anis Ammous Copyright © 2012 Bassem Omri et al. All rights reserved. Mon, 17 Dec 2012 11:16:45 +0000 http://www.hindawi.com/journals/ape/2012/676010/ Integration of STATCOM with energy storage devices plays an imperative role in improving the power system operation and control. Significant research has been done in this area for practical realization of benefits of the integration. This paper, however, pays particular importance to the performance improvement for the transients as is achievable by STATCOM with battery-powered storage systems. Application of STATCOM with storage in regard to intermittent renewable energy sources such as wind power generation is also discussed in the paper. At the beginning of this paper, an overall review of the STATCOM and energy storage systems are elaborated. A brief overview of the advantages of using STATCOM in conjunction to energy storage systems in achieving power system stability is presented. In the second part of the paper, a typical transient stability model of a STATCOM is presented. The dynamics of real and reactive power responses of the integrated system to transients is studied. The study is aimed at showing that the combination of STATCOM and battery energy storage significantly improves the performance of the system. The final results show that the STATCOM reactive power/voltage control helps in transient stability enhancement. Arindam Chakraborty, Shravana K. Musunuri, Anurag K. Srivastava, and Anil K. Kondabathini Copyright © 2012 Arindam Chakraborty et al. All rights reserved. Mon, 17 Dec 2012 08:27:31 +0000 http://www.hindawi.com/journals/ape/2012/643716/ This paper addresses the switching transients in multibranch thyristor-switched capacitors (TSCs). The current transients following the addition of a branch to a group of already connected ones are analyzed. Expressions for both its fundamental and its oscillatory components are given in terms of the power network voltage, frequency, short-circuit level, and the switching angle. The relations include also the compensator parameters such as its total reactive power rating, total number of branches, the number of already connected branches, and the initial voltage on the capacitor involved in the switching transient. An expression for the distortion of the supply current is also given. A minimization procedure is presented for identifying the optimal switching angle leading to the least magnitude of the oscillatory current. Switching when the instantaneous supply voltage is equal to the initial voltage will result in the least oscillatory current only in the two special cases of a single-branch compensator, or in the switching of the first branch of a multi-branch TSC. The effect of both the total number of branches and the branch switching steps on the oscillatory current and on the optimal switching angle is also discussed. The advantage of the suggested procedure is demonstrated by investigating several case studies. Mohamed M. Saied Copyright © 2012 Mohamed M. Saied. All rights reserved. Sun, 09 Dec 2012 10:01:21 +0000 http://www.hindawi.com/journals/ape/2012/208231/ This paper presents an investigation of voltage-and-frequency-(VF-) based battery energy storage system (BESS) controller used in micro grid for analyzing the optimum capability of plant. Microgrid is formed by using three hydropower plants feeding three-phase four-wire load. The proposed controller is used for load balancing, harmonic elimination, load leveling, and neutral current compensation. The proposed BESS controller permits the selection of an optimum voltage level of battery and allows independent current control of each phase. The main emphasis is given on maintaining constant voltage and frequency within the micro grid during transient conditions. Micro grid with power plant and its controller is modeled in MATLAB/Simulink using Power System Blockset (PSB) toolboxes. Monika Jain, Sushma Gupta, Deepika Masand, and Gayatri Agnihotri Copyright © 2012 Monika Jain et al. All rights reserved. Wed, 28 Nov 2012 08:00:30 +0000 http://www.hindawi.com/journals/ape/2012/805958/ This paper describes and demonstrates the principle and efficacy of a novel direct current fault interruption scheme using a reactor in series with a controlled rectifier and a conventional AC circuit breaker. The presence of the series reactor limits the capacitive discharge current from the DC filter capacitor at the output terminals of the phase-controlled rectifier. In addition, the series reactor along with the filter capacitor forms an underdamped series RLC circuit which forces the fault current to oscillate about zero. This synthetic alternating current can then be interrupted using a conventional AC circuit breaker. The selection criteria for the series reactor and overcurrent protection are presented as well. Using the proposed scheme for an example case, a DC fault current magnitude is reduced from 56 kA to 14 kA, while the interruption time is reduced from 44 ms to 25 ms. Saurabh Kulkarni and Surya Santoso Copyright © 2012 Saurabh Kulkarni and Surya Santoso. All rights reserved. Sun, 25 Nov 2012 16:13:30 +0000 http://www.hindawi.com/journals/ape/2012/259756/ Wide-input, low-voltage, and high-current applications are addressed. A single-ended isolated topology which improves the power efficiency, reduces both switching and conduction losses, and heavily lowers the system cost is presented. During each switching cycle, the transformer core reset is provided. The traditional tradeoff between the maximum allowable duty-cycle and the reset voltage is avoided and the off-voltage of active switches is clamped to the input voltage. Therefore, the system cost is heavily reduced and the converter is well suited for wide-input applications. Zero-voltage switching is achieved for active switches, and the power efficiency is greatly improved. In the output mesh, an inductor is included making the converter suitable for high-current, low-voltage applications. Since the active clamp forward converter is the closest competitor of the proposed converter, a comparison is provided as well. In this paper, the steady-state and small-signal analysis of the proposed converter is presented. Design examples are provided for further applications. Simulation and experimental results are shown to validate the great advantages brought by the proposed topology. V. Boscaino and G. Capponi Copyright © 2012 V. Boscaino and G. Capponi. All rights reserved. Sun, 25 Nov 2012 07:40:34 +0000 http://www.hindawi.com/journals/ape/2012/502763/ This paper presents design consideration and performance analysis of novel reduced parts online three-phase uninterruptible power supply (UPS) system. The proposed UPS system is based on reduced switch count dual bridge matrix converter. It employs only six power switches and results in reducing the cost of the system compared to conventional online UPS topologies, while achieving excellent performance. The performance of the proposed system is evaluated through simulation in terms of input/output waveforms quality and shows the viability of topology. Bahram Ashrafi and Mehdi Niroomand Copyright © 2012 Bahram Ashrafi and Mehdi Niroomand. All rights reserved. Sun, 11 Nov 2012 17:40:37 +0000 http://www.hindawi.com/journals/ape/2012/529178/ The ferroresonance or nonlinear resonance is a complex phenomenon, which may cause overvoltage in the electrical power system and endangers the system reliability and operation. The ability to predict the ferroresonance in the transformer depends on the accuracy of the transformer model used. In this paper, the effect of the new suggested ferroresonance limiter on the control of the chaotic ferroresonance and duration of chaotic transients in a potential transformer including nonlinear core losses is studied. To study the proposed ferroresonance limiter, a single phase 100 VA, 275 kV potential transformer is simulated. The magnetization characteristic of the potential transformer is modeled by a single-value two-term polynomial. The core losses are modeled by third order power series in terms of voltage and include core nonlinearities. The simulation results show that the ferroresonance limiter has a considerable effect on the ferroresonance overvoltage. Hamid Radmanesh, G. B. Gharehpetian, and Hamid Fathi Copyright © 2012 Hamid Radmanesh et al. All rights reserved. Wed, 31 Oct 2012 15:25:00 +0000 http://www.hindawi.com/journals/ape/2012/327186/ A dynamic voltage restorer (DVR) with no energy storage is studied. By using a matrix converter instead of the conventional AC/DC/AC converters, elimination of the DC-link capacitor is possible. The switching algorithm of matrix converter is the space vector modulation. There are different compensation algorithms to control the conventional DVR. These methods have been analyzed in this paper for the proposed matrix-converter-based DVR. A deep analysis through different diagrams would show the advantages or disadvantages of each compensation method. Equations for all methods are derived, and the characteristics of algorithms are compared with each other. Amin Shabanpour and Ali Reza Seifi Copyright © 2012 Amin Shabanpour and Ali Reza Seifi. All rights reserved. Wed, 31 Oct 2012 10:31:50 +0000 http://www.hindawi.com/journals/ape/2012/409671/ This paper investigates the numerical issue of a discrete-time induction-motor emulator implementation. The stability analysis of the finite-word-length implementation shows a coupling between required word length and the sample rate. We propose specific guidelines to analyze this coupling and to estimate the required data word length for both signals and coefficients of the model. To respect algorithm requirements, an FPGA-based implementation was used for architecture development. The direct torque control is implemented to verify in real time the AC-motor emulator prototype. L. Charaabi Copyright © 2012 L. Charaabi. All rights reserved. Tue, 30 Oct 2012 09:45:24 +0000 http://www.hindawi.com/journals/ape/2012/286861/ This paper is concerned with performance of the current shaping network in Average Current Mode (ACM) Active Power Factor Correction (APFC) systems. Theoretical expressions for the ripple components are derived. Then, ripple interaction and impact on the current loop reference signal are investigated. A modification of the controller network is suggested that results in an improved Total Harmonic Distortion (THD). Design guidelines are suggested. The theoretical predictions were validated by simulation. Alexander Abramovitz Copyright © 2012 Alexander Abramovitz. All rights reserved. Thu, 18 Oct 2012 17:34:51 +0000 http://www.hindawi.com/journals/ape/2012/730473/ An isolated bidirectional full-bridge DC-DC converter with flyback snubber for supplying a resistive load is simulated and experimentally verified. The DC-DC converter for high conversion ratio, high output power, and soft start-up capability is presented in this paper. The circuit consists of a capacitor, a diode, and a flyback converter. These components help to clamp the voltage spikes caused by the current difference between the current fed inductor and leakage inductance of the isolation transformer. The switches are operated by soft-switching technology. The suppression of inrush current which is usually found in the boost mode start-up transition is presented here. The simulated and experimental results for output voltage, output current, and power for both buck and boost modes are presented. D. Kirubakaran and Rama Reddy Sathi Copyright © 2012 D. Kirubakaran and Rama Reddy Sathi. All rights reserved. Sun, 14 Oct 2012 08:25:41 +0000 http://www.hindawi.com/journals/ape/2012/871652/ The basic power quality problems in the distribution network are voltage sag (dip), voltage flickering, and the service interruptions. STATCOM is a Flexible AC Transmission Systems (FACTS) technology device which can independently control the flow of reactive power. This paper presents the simulation and analysis of a STATCOM for voltage dip and voltage flickering mitigation. Simulations are carried out in MATLAB/Simulink to validate the performance of the STATCOM. A comparison between the six-pulse inverter and the five-level diode-clamped inverter is carried out for the performance of 66/11 KV distribution system. M. S. Ballal, H. M. Suryawanshi, and T. Venkateswara Reddy Copyright © 2012 M. S. Ballal et al. All rights reserved. Wed, 19 Sep 2012 10:18:54 +0000 http://www.hindawi.com/journals/ape/2012/327157/ Switching converters are used in electric drive applications to produce variable voltage, variable frequency supply which generates harmful large dv/dt and high-frequency common mode voltages (CMV). Multilevel inverters generate lower CMV as compared to conventional two-level inverters. This paper presents simple carrier-based technique to control the common mode voltages in multilevel inverters using different structures of sine-triangle comparison method such as phase disposition (PD), phase opposition disposition (POD) by adding common mode voltage offset signal to actual reference voltage signal. This paper also presented the method to optimize the magnitude of this offset signal to reduce CMV and total harmonic distortion in inverter output voltage. The presented techniques give comparable performance as obtained in complex space vector-based control strategy, in terms of number of commutations, magnitude, and rate of change of CMV and harmonic profile of inverter output voltage. Simulation and experimental results presented confirm the effectiveness of the proposed techniques to control the common mode voltages. Pradyumn Chaturvedi, Shailendra Jain, and Pramod Agarwal Copyright © 2012 Pradyumn Chaturvedi et al. All rights reserved. Thu, 13 Sep 2012 19:09:15 +0000 http://www.hindawi.com/journals/ape/2012/837602/ Power electronics are a core enabling technology for local area power networks and microgrids for renewable energy, telecom, data centers, and many other applications. Unfortunately, the modeling, simulation, and control of power electronics in these systems are complicated when using traditional converter models in conjunction with the network nodal equations. This work proposes a change of variables for the power electronic converter models from traditional voltage and currents to input conductance and stored energy. From this change of state, a universal point of load converter model can be utilized in the network nodal equations irrespective of the topology of the converter. The only impact the original converter topology has on the new model is the bounds on the control and state variables, and the mapping back to the switching or duty cycle controls. The proposed approach greatly simplifies the modeling of local area power networks and microgrids. This simpler model can be used to study stability and energy utilization and develop high-level control strategies that were not previously feasible. Gregory M. Vosters and Wayne W. Weaver Copyright © 2012 Gregory M. Vosters and Wayne W. Weaver. All rights reserved. Mon, 10 Sep 2012 09:40:55 +0000 http://www.hindawi.com/journals/ape/2012/764038/ Accurate flux estimation and control of stator flux by the flux control loop is the determining factor in effective implementation of DTC algorithm. In this paper a comparison of voltage-model-based flux estimation techniques for flux response improvement is carried out. The effectiveness of these methods is judged on the basis of Root Mean Square Flux Error (RMSFE), Total Harmonic Distortion (THD) of stator current, and dynamic flux response. The theoretical aspects of these methods are discussed and a comparative analysis is provided with emphasis on digital signal processor (DSP) based controller implementation. The effectiveness of the proposed flux estimation algorithm is investigated through simulation and experimentally validated on a test drive. Bhoopendra Singh, Shailendra Jain, and Sanjeet Dwivedi Copyright © 2012 Bhoopendra Singh et al. All rights reserved. Wed, 29 Aug 2012 08:55:32 +0000 http://www.hindawi.com/journals/ape/2012/237259/ This paper deals with the use of triphase shunt active filter which is able to compensate current harmonics, reactive power, and current unbalance produced by nonlinear loads. To perform the identification of disturbing currents, a very simple control method is introduced. It’s formed by a DC voltage regulator and a balance between the average power of load and the active power supplied by the grid. The output current of the voltage source inverter (VSI) must track the reference current. This is done by a neural controller based on a PI-Fuzzy adaptive system as reference corrector. Also to regulate the DC link capacitor voltage a fuzzy logic adaptive PI controller is used. Moulay Tahar Lamchich Copyright © 2012 Moulay Tahar Lamchich. All rights reserved. Thu, 09 Aug 2012 09:08:19 +0000 http://www.hindawi.com/journals/ape/2012/635715/ This paper proposes a simpler and more accurate expression for estimation of leakage inductance in E core transformer, which is the most widely used transformer structure. The derived expression for leakage inductance accounts for the flux extending into air. The finite element method (FEM) analysis is made on the secondary shorted transformer to observe the H-field pattern. The results obtained from FEM analysis are used for approximating the field that is extending into air to derive an expression for leakage inductance. This expression is experimentally validated on prototype transformers of different core dimensions. Sivananda Reddy Thondapu, Mangesh B. Borage, Yashwant D. Wanmode, and Purushottam Shrivastava Copyright © 2012 Sivananda Reddy Thondapu et al. All rights reserved.