iosr-JEEE   International Conference on Advances in Engineering & Technology – 2014 (ICAET-2014)

Abstract: Amongst many types of electrical motors, induction motors still enjoy the same popularity as they did a century ago. Several factors which include robustness, low cost and low maintenance have made them popular for industrial applications when compared to dc and other ac motors. Another aspect in induction motor drives which has been researched recently is the use of multiphase induction motors where the number of stator phases is more than three. Multiphase induction motors have found many applications such as electric/hybrid vehicles, aerospace applications, ship propulsion etc. This paper focuses on testing of designed, developed prototype six phase induction motor at M/sJyoti Ltd,.Mogar, Anand, Gujarat and then comparison with equivalent three phase induction motor is discussed. Problems faced at the time of actual development are discussed in detail and solution to overcome those problems is given. Keywords – Six phase induction motor, winding design, and development.

[1] G. K. Singh, "Multiphase Induction Machine drive research", Elsevier Journal, Electric Power System Research, Vol. 61, pp. 139-147, 2002.

[2] Emil Levi, "Recent Developments in High Performance Variable-Speed Multiphase Induction Motor Drives" Sixth International Symposium Nikola Tesla, Belgrade, Serbia. 18th – 20th October, 2006

[3] K. Gopalkumar, Mahopatra, "A novel scheme for six phase induction motor with open end windings." 28th Annual Conference of IEEE Industrial Electronics Society, Spain. 5th - 8th November, 2002.

[4] Hamid Toliyat, Emil Levi, "A novel concept of a multiphase, multi-motor vector controlled drive system supplied from a single voltage source inverter" IEEE Transactions on Power Electronics, Vol. 19, No. 2, pp. 320-335. March 2004.

[5] G. K. Singh, S. K. Lim, "A Simple Indirect Field-oriented Control Scheme for Multiphase Induction Machine", IEEE Transactions on Industrial Electronics, Vol. 52, No. 4, August 2005.

Abstract: This paper proposes a unique transformer protection scheme based on correlation coefficient which can effectively differentiate between internal and external faults. It can also identify the inrush phenomena and presence of fault while energizing transformer. Current entering and leaving the transformer have a strong relationship during normal and external fault condition. However during disturbance this relationship is affected, highlighting the change in coefficient value. The change in correlation coefficient value is proposed as a measure to detect the fault and inrush phenomena under various power system conditions. The proposed scheme also found effective to classify different types of short circuit faults. Results from simulation and real time data obtained from the field, supports the feasibility of the concept.

Keywords – Transformer protection, Transformer inrush, Correlation coefficient, Fault detection, Fault classification

C. Russell Mason, The art and science of protective relaying (General Electric Series, Wiley, 1956). George W. McKenna, Theory and application of transformer differential protection, AIEE Transactions, 69, 1950, 1197-1202. L.F. Kennedy and C.D. Hayward, Harmonic-current-restrained relays for differential protection, AIEE Trans, 57, 1938, 262-271.

Abstract: BLDC Motors have advantages over brushed DC Motors and IM. They have better speed verses torque characteristics, high dynamic response, high efficiency, long operating life, noiseless operation, higher speed ranges, and rugged construction. Also, torque delivered to motor size is higher, making it useful in application where space and weight are critical factors. With these advantages BLDC motors find wide spread application in automotive appliance, aerospace medical, and instrumentation and automation industries. In this paper, drive for speed control of BLDC motor using microcontroller PIC18F4520 was developed. For speed control sinusoidal PWM technology was implemented. Simulation was carried out using MATLAB/SIMULINK software for speed control of BLDC drive. Based on mathematical model of BLDC drive, simulation results were demonstrated. It presents the simulated waveforms fit theoretical analysis well.

Keywords: BLDC, MATLAB/SIMULINK, PIC 18F4520, VSI,

[1] A. R. Millner, "Multi-hundred horsepower permanent magnet brushless disc motors," in Proc. IEEE Appl. Power Electron. Conf. (APEC'94), Feb. 13–17, 1994, pp. 351–355.

[2] Kun Wei , Zhengli Lou , Zhongchao Zhang, "Research on the Commutation Current Prediction Control in Brushless DC Motor"

Abstract: This paper deals with modelling and simulation technique of a Dynamic Voltage Restorer (DVR) to alleviate the problem of voltage sags and swells and its severe impact on non linear loads or sensitive loads. Dynamic Voltage Restorer (DVR) is one of the most reliable and efficient custom power devices used in power distribution network. This paper describes space vector PWM technique used for VSI. There are two important parts in the DVR one is to detect the voltage disturbance and the other is to compensate it as fast as possible. The proposed control scheme is simple to design and has excellent voltage compensation capabilities. Effectiveness and fast response of proposed technique is investigated through computer simulation by using MATLAB/SIMULNK software. The simulation results have shown validation of the control system

Keywords - Dynamic Voltage Restorer (DVR), power quality, SVPWM, voltage sags, voltage swells.

L. Sarıbulut, Performance analysis of unified power flow controller (UPFC) by using different controllers, M.Sc. thesis, Department of Electrical and Electronic Engineering, Cukurova University, 2008. Y.H. Song, A.T. Johns, Flexible AC Transmission Systems (FACTS), IEE Power and Energy Series, 1999. R. Mihalic, P. Zunko, D. Povh, Improvement of transient stability using unified power flow controller power delivery, IEEE Transactions 11 (1996) 485–492. A.A. Edris, Proposed terms and definitions for flexible AC transmission systems (FACTS), IEEE Transactions 2 (1997) 1848–1853.

Abstract: Shunt Active power filters allied in parallel with non linear load to remove the current harmonics and to compensate reactive power, which improves the stability of the power system. Fault tolerant control is the ability of the system to function in an acceptable behaviour after sustaining a fault to provide adequate reliability. In this paper we discussed various types of faults that may appear in three phase shunt active power filters. Further we also studied various fault tolerant strategies for shunt active power filters .To develop this fault tolerant model, we simulate using Matlab/Simulink to setup a model by injecting faults such as open circuit, short circuit into the system and the system performance is demonstrated in the presence of faults and also in the absence of faults.

Key words: Active power filters, Fault tolerant, Fault, Reliability

[1] Fujita H, "Single active filter using an H-Bridge PWM converte with a sampling frequency quadruple of switching frequency", Power Electronics, IEEE transactions, 24: 934-941,2009

[2] Luo A, Shuai Z, Shen Z J, Wenji Z, Xianyong X, "design considerations for maintaining Dc Side voltage of hybrid filter with injection circuit", Power Electronics, IEEE transactions, 24: 75-84, 2009

[3] Jou H.L, Wu K.D, Wu J.C, Chiang W., "A Three phase four wire power filter comprising a three phase three wire active power filter and a zig-zag transformer", Power electronics, IEEE Transactions, 23, 252-259, 2008

[4] Vodyakho O, Kim T, "Shunt active filter based on three level inverter for three phase 4 wire systems", Power Electronics, IET, 2: 216-226, 2009

[5] Habrouk E, Darwish M, Mehta M.K, " Active power filters: A review", Electric power applications, IEEE Proceedings, 147: 403-413

[6] P.Poure, P.Weber, D.Theilliol, S.Saadate, "Fault Tolerant Control of a three phase three wire shunt active filter system based on reliability analysis". Electric Power systems Research 79(2009) 325-334.

[7] Yantao Song and Bingsen Wang, Senior memberIEEE "Survey on Reliability of power electronic systems" IEEE transactions on power electronics, vol.28, No.1, 2013 [8] Ribeiro RLA, Profumo F, Jacobina, CB, Griva.G "Two fault tolerant control strategies for shunt active power filter systems", IECON, 2002, vol.1, pp.792-797

[9] Jacobina.C.B, Correa M.B.R, Pinheiro R.F, Lima, A.M.N, "Improved fault tolerance of active power filter system" Power Electronics Specialists conference, 2001, vol.3, pp.1635-1640

Abstract: This paper narrates the application of DVR to optimize the power quality problems such as voltage sag, voltage swell and harmonics. Among all these three power quality problems, two are identified as the major concern to the customers namely voltage sag and voltage swell. One of the well known solutions to mitigate the power quality problem is to inject the voltage as well as power into the system with the help of DVR. The DVR is a power electronics based device that is commonly for voltage sag and voltage swell mitigation at the point of connection. A control technique based on a proportional integral (PI) controller is implemented. In fact with the aid of Pulse width modulation (PWM) inverters capable of generating accurate high quality voltage waveforms from the power electronic device. Simulation results shows the effectiveness of proposed method by MATLAB/Simulink.

Keywords: Dynamic Voltage Restorer (DVR), Power quality, Pulse Width Modulation (PWM), Voltage Source Converter (VSC).

[1] M. Bollen, Understanding power quality problem, voltage sags and interruption. Piscataway, NJ: IEEE Press, USA, 1999.

[2] Francisco Jurado "Neural Network Control For Dynamic Voltage Restore" IEEE Transaction on Industrial Electronic . Vol 51,No.3, June 2004.

[3] A. Hernandez, K. E. Chong, G. Gallegos, and E. Acha, "The implementation of a solid state voltage Source in PSCAD/EMTDC," IEEE Power Eng. Rev., pp. 61–62, Dec. 1998.

[4] I. T. Fernando, W. T. Kwasnicki, and A. M. Gole. Modeling of conventional and advanced static var compensators in electromagnetic transients simulation program.

[5] Rosli Omar and Nasrudin Abd Rahim , ― Mitigation of Voltage Sags/Swells using Dynamic Voltage Restorer (DVR),‖ARPN Journal of Engineering and Applied science,Vol,4,June 2, 2009 .

[6] Margo P.M. Hery P.M. Ashar,, T. Hiyama,―Balanced voltage sag correction using DVR based on Fully polar controller‖, ICICIC 2007 Conference Proceedings, Kumamoto ,Japan.

[6] A.Ramasamy,K.I.Rengan,V.K. Ramachandaramurthy ―Dynamic Voltage Restorer for Voltage Sag Compensation‖, International Conference on Power Electronics and Drive Systems (PEDS) 2005, Volume 2, 28-01, Nov.2005, pp.1289-1294.

[7] A. Ghosh and G. Ledwich, "Power Quality Enhancement Using Custom Power Devices," Kluwer Academic Publishers, 2002. [8] H. Awad, J.Svensson, M. Bollen, "Mitigation of Unbalanced Voltage Dips Using Static Series Compensator'', IEEE Trans. On Power Elec., Vol. 19, No. 13, May 2004 [9] N.G. Hingorani, "Introducing Custom Power in IEEE Spectrum," 32p, pp. 4l-48, 1995. Electrical Power Systems. [10] E. Acha, V. G. Agelidis, O. Anaya-Lara, and T. J. E. Miller, Electronic Control in London, U.K.:Butter Worth-Heinemann, 2001.

Abstract: Switched Reluctance Machines are receiving significant attention from industries, because of its simple structure; inexpensive manufacturability and reliability make it superior to other electric machines. The objective of this paper is to achieve desired speed performance of 6/4 Switched Reluctance Motor (SRM) with reduced torque ripples. To achieve improved speed performance, PI+FUZZY controller was introduced. Double closed loop control system is used for the better speed performance characteristics. In order to minimize the torque ripple, three different strategies are proposed. Simulation results reconfirm the effectiveness in the aspects of better speed performance and torque ripple reduction

Keywords: Current controller, Speed controller, Switched reluctance motor (SRM), Torque ripple.

[1] Zhang Zhihui and Li Yuren, "Numerical and Analytical Modeling of Switched Reluctance Machines", Journal of computers, vol.7, no.12, Dec 2012.

[2] Shoujun song and Wieguo Lui A Comparative study on "Modeling methods for Switched Reluctance Machines" Computer science information, vol.3, no.2, May 2010.

[3] Somesan Liviu, Padurariu Emil, Husain Iqbal, Viorel Ioan-Adrian, Szabo Loránd, "Simple Analytical Models of Switched Reluctance Motor for Design and Control Purpose" Journal of computer science and control systems, vol.4, no.1 May 2011.

[4] Soares F and Costa Branco, "Simulation of a 6/4 switched reluctance motor based on Matlab/Simulink environment," IEEE Transactions on Aerospace and Electronic Systems, volume 37, issue 3, July 2001.

Abstract: The research study takes a look at tha impact slip rings power losses of three phase slip ring inducation motor. The output slip power losses are more during speed control in two methods which one is doubly-fed method.

[1]. A. Lavi and R. L. Polge, "Induction motor speed control with static inverter in the rotor", IEEE Trans, Power Appar.Syst., vol. 85 pp. 76-84, Jan. 1996. [2]. T. Hori. H. Nagase, and M. Hombu, "Induction Motor Control System", Industrial Electronics Handbook, J.D. Irwin, pp. 310-315, CRC Press, 1997. [3]. T. Wakabayashi, T. Hori. K. Shimzu, and T. Yoshioka, "Commutatorless Kramer control system for large capacity induction motors for driving water service pumps". IEEE/IAS Annu. Meet. Conf. Rec., pp 822-828, 1976. [4]. H. W. Weiss, "Adjustable speed ac drive system for pump and compressors application", IEEE Trans, On Ind. Appl., Vol. 10 ,pp. 157-162, Jan/feb 1975. [5]. P. Zimmermann, "Super Synchronous Static Converter Cascade", Conf. Rec. IFAC Symp On Control in Power Elec. and Electrical Drives, pp. 559-572, 1997.
[6]. R. Datta and V. T. Ranganathan. "Decoupled control of active and reactive power for a grid- connected doubly-fed wound rotor induction machine without position sensors." IEEE/IAS Annu. Meet. Conf. Rec., pp. 2623-2630, 1999.

Abstract: The rotating machines are the heart of industries. This rotational energy along with driving a load can be used as a source for free energy power generation as a by- product. This paper proposes a novel technology to convert the rotational free energy available from rotating machines to electrical energy using repulsion magnet technique. The proposed technology employs the theory of magnetic repulsion to utilize the free energy. The system uses permanent magnets to produce repulsion and this repulsive force produces a torque which drives a DC generator. The repulsive magnet disc consists of two magnetic discs of which one is mounted in the rotating machine and the other is connected to the DC generator. During driving a load, the rotating machine on rotation rotates disc 1. The repulsion between the two magnets makes the disc 2 to rotate which forms the mechanical input for DC generator. Thus the free energy available is used for power generation by repulsion technique. The power output from the DC generator can be stored in batteries or used to drive any AC loads through an inverter. Thus the free energy can be effectively utilized at no cost.

Keywords: Batteries, DC generator, Free energy, Inverter, Machines, Magnetic repulsion.

[1] [1] N. Mohan, T. M. Undeland, and W. P. Robbins, Power Electronics - Converters, Applications,and Design, 2nd ed: John Wiley & Sons, Inc., 1995.
[2] [2] "Matlab 6, Release 12.1." Natick, Massachusetts: The MathWorks (www.mathworks.com), 2006.
[3] [3] "PSIM Version 7.0." Woburn, MA: Powersim Inc. (www.powersimtech.com), 2006.
[4] [4] M. Trigg, "Digital Sinusoidal PWM Generation using a Low-cost Micro-controller Based Single-Phase Inverter," presented at ETFA 2005, Catania, Italy, 2005.
[5] [5] M. C. Trigg, H. Dehbonei, and C. V. Nayar, "Digital Sinusoidal PWMs for a Microcontroller based Single-Phase Inverter. Part 1: Principles of digital sinusoidal PWM generation," IJE Power electronics andinstrumentation hardware, 2005.

Abstract: This paper mockles the problem of high torque ripple in current controlled switched reluctance motor (SRM) drives. Torque ripple reduction below the base speed of the motor is studied through adjustment of both turn-on and turnoff angles. A multi objective optimization function is used to determine the proper turn-off angle in each operation point. Based on a proposed approach on intersecting of the consecutive phase currents, the turn-on angle is properly adjusted. The proposed method is quite easy to implement and does not need the exact parameters of the motor to run. Simulations and comparisons are also presented to validate the proposed control scheme. High speed drive systems are much interested in the industrial application such as blower, compressor, pump and spindle due to the compact size and high efficiency. In recent, the demands of high speed drives are much increased due to the mechanical advantages of high speed system. SRMs (Switched Reluctance Motors) have simple structure and inherent mechanical strength without rotor winding and permanent magnet.

Keywords: Switched Reluctance Motor, Speed control, Commutation angle , Drives.

[1] A. K. Jain, N. Mohan, "SRM power converter for operation with high demagnetization voltage", Industry Applications, IEEE Transactions on, vol. 41, Issue 5, pp.12241231, Sept.-Oct. 2005.

[2] A. Dahmane, F. Meebody, F.-M. Sargos, "A novel boost capacitor circuit to enhance the performance of the switched reluctance motor", Power Electronics Specialists Conference, 2001, pp.844-849, 17-21 Jun. 2001. [3] B.H. Bae, S. K. Sul, J.H. Kwon, J.S. Shin, "Implementation of sensorless vector control for super-high speed PMSM of turbo-compressor", in Proc. IEEE Industry Applications Conf., vol.2, Oct. 2001, pp.1203–1209.

[4] C. H. Choi, S. H. Kim, Y. D. Kim, and K.H. Park, "A new torque control method of a switched reluctance motor using a torque-sharing function," IEEE Trans. on Magnetics, vol. 38, no. 5, September 2002, pp. 3288-3290. Proceedings Papers: [

1] C. Sreekumar, V. Agarwal, "A Hybrid Control Algorithm for Voltage Regulation in DC–DC Boost Converter," IEEE Trans. on Industrial Electronics, vol. 55, no. 6, pp. 25302538, June 2008. [2] D.H. Lee, J. Liang, Z.G. Lee, and J. W. Ahn," A Simple Nonlinear Logical Torque Sharing Function for Low Torque Ripple SR Drive", Industrial Electronics, IEEE Transactions on, vol. 56, no.8, pp. 3021-3028, 2009.

[3] D. H. Lee, J. W. Ahn, "A Novel Four-Level Converter and Instantaneous Switching Angle Detector for High Speed SRM Drive", IEEE Trans. on Power Electronics, Vol. 22, No. 5, pp. 2034-2041, 2007.

Abstract: The multilevel began with the three level inverter. Use of conventional two – level pulse width modulation (PWM) inverter provide less distorted current and voltage but at cost of higher switching losses due to high switching frequency. Multilevel inverter are emerging as a viable alternative for high power, medium voltage application. This paper compare total harmonics distortion in three level and five level diode clamped multilevel inverter. Diode –clamped three phase topology is considered for study. A sinusoidal PWM technique is used to control the switches of the inverter. Simulation study confirms the reduction in harmonics distortion. .

Keywords: Harmonics, Multilevel Inverter, Neutral Point Clamped Inverter, PWM, SPWM, and Total Harmonic Distortion..

[1] McGrath, B.P.; Holmes, D.G.; "Multicarrier PWM strategies for multilevel inverters," Industrial Electronics, IEEE Transactions on, vol.49, no.4, pp. 858- 867Aug 2002 doi: 10.1109/TIE.2002.801073

[2] B. N. Mwinyiwiwa, Z.Wolanski, and B. T. Ooi, "Microprocessor implemented SPWM for multiconverters with phase-shifted triangle carriers," in Conf. Rec. IEEE-IAS Annu. Meeting, NewOrleans, LA, Oct. 1997, pp. 1542–1549.

[3] O. Bouhali, B. Francois, E. M. Berkouk, and C. Saudemont, "DC Link Capacitor Voltage Balancing in a Three-Phase Diode Clamped Inverter Controlled by a Direct Space Vector of Line-to-Line Voltages", IEEE Trans. on Power Electronics, Vol.22, No.5, 2007, pp.1636-1648.

[4] AnshumanShukla, ArindamGhosh and Avinash Joshi, "Control Schemes for DC Capacitor Voltages Equalization in Diode-Clamped Multilevel Inverter Based DSTATCOM", IEEE Trans. on Power Delivery, Vol.23, No.2, 2008, pp.1139-1149.

[5] BerrezzekFarid and BerrezzekFarid, "A Study of New Techniques of Controlled PWM Inverters", European Journal of Scientific Research, ISSN 1450-216X, Vol.32, No.1, 2009, pp.77-87.

[6] Mohan M. Renge and Hiralal M. Suryawanshi, "Five-Level Diode Clamped Inverter to Eliminate Common Mode Voltage and Reduce dv/dt in Medium Voltage Rating Induction Motor Drives", IEEE Trans. on Power Electronics, Vol.23, No.4, 2008, pp.1598-1607.

[7] C.Govindaraju and Dr.K.Baskaran, ―Optimized Hybrid Phase Disposition PWM Control Method for Multilevel inverter‖, International Journal of Recent Trends in Engineering, vol 1, no.3, pp.129-134, 2009. [8] Haiwen Liu, Leon M.Tolbert, Surin Khomfoi, Burak Ozpineci and Zhong Du, ―Hybrid Cascaded Multilevel Inverter with PWM Control Method‖, IEEE Conf. Rec :978-1-4244-1668-4/08, pp.162-166, 2008. [P9] Keith A. Corzine, Mike W. Wielebski, Fang Z. Peng and Jin Wan, ―Control of Cascaded Multilevel Inverter‖, IEEE Trans. on Power Electro., vol.19, no.3, pp.732-738, 2004.

Abstract: Continuous online monitoring of transmission line is required for proper functioning of power system. This paper presents two simulink model one for single transmission line, singly fed and the other for parallel transmission line doubly fed and presents the simulation result which shows the continuous variation in transmission line impedance before, during and after the fault. Power system fault identification using information conveyed by the wavelet analysis of power system transients is proposed for detecting types of transmission line faults. The work presented in this paper is focused on identification of simple power system faults. Discrete Wavelet Transform (DWT) analysis of the transient disturbance caused as a result of occurrence faults is performed. The maximum detail coefficient, energy of the signal and the ratio of energy change of each type of simple simulated fault are characteristic in nature and used for distinguishing fault types. Electromagnetic transients in power systems result from a variety of disturbances on transmission lines, such as faults, are extremely important.

Keywords: Distance protection, Mutual coupling effect, R-X plot, Series compensation, Type of faults.

[1] C.K. Jung et al. K.H. Kim, J.B. Lee, Bernd Klo ckl b, "Electrical Power and Energy Systems," IEEE Winter Meeting, paper, Wonkwang University, 344(2), 16 November 2006.

[2]. J. Upendar etc, "Comprehensive Adaptive Distance Relaying Scheme for Parallel Transmission Lines" IEEE transactions on power delivery, vol. 26, no. 2, april 2011.

Abstract: Transmission line equivalent circuit parameters are often 25% to 30% in error as compared to values measured by the SCADA system. These errors cause the economic dispatch to be wrong, and lead to increased costs or incorrect billing. The parameter errors also affect contingency analysis, short circuit analysis, distance relaying, machine stability calculations, transmission planning, and state estimator analysis. An economic example is used to demonstrate the affect of transmission line errors. SCADA measurements from several utilities are used to compute the 'real world' value of the transmission line parameters. State estimation with the estimated parameters is compared to the computations using the theoretical.

BOOKS By HADI SAADAL "Power System Analysis", Tata Mc Graw Hill Publishing Company, New Delhi, 2002. By C.L.WADHWA "Electrical Power System "New Age International (P) Ltd. New Delhi, 2001. By SUNIL.S.RAO "Switchgear Protection and Power" Khanna Publisher, 2-B Market, New Sarak, Delhi 2000.

Abstract: Multi-String Multilevel inverters are the new technology of power converter options for high-power applications. This paper presents a three phase multistring multilevel inverter for micro grid applications. The multilevel topology consists of several H-bridge cells connected in series, each one connected to a string. The simplified multilevel inverter needs only 6 switches whereas 8 switches are required in the conventional cascaded H-bridge multilevel inverter. Two active switches are operated across the line frequency. The multistring inverter topology offers better output waveforms, small LC filter size, less electromagnetic interference and total harmonic distortion. Finally, the results are compared between the without and with phase disposition pwm technique for both the multistring cascaded H-Bridge inverter and multistring multilevel inverter of in MATLAB/Simulink environment.

Key Words: Multistring Multilevel, Micro-grid, Cascaded inverters.

[1] M. Calais and V. G. Agelidis, ―Multilevel converters for single-phase grid connected photovoltaic systems—an overview,‖ in Proceedings of IEEE International Symposium on Industrial Electronics, vol. 1, pp. 224–229, 1998.
[2] Yi-Hung Liao, Ching-Ming ―Newly- Constructed Simplified Single-Phase Multistring Multilevel Inverter Topology for Distributed Energy Resources‖, IEEE Transactions on Power Electronics,vol. 26, no. 9, pp. 2386 - 2392, 2011.
[3] N. Hatziargyriou, H. Asano, R. Iravani, and C. Marnay, ―Microgrids,‖ IEEE Power & Energy Magazine, vol. 5,no. 4, pp.78-94, Jul/Aug. 2007.
[4] F. Katiraei, R. Iravani, N. Hatziargyriou, and A. Dimeas, ―Microgrids management,‖ IEEE Power Energy Mag., vol. 6, no. 3, pp. 54-65, May/Jun. 2008.
[5] C. L. Chen, Y.Wang, J.S.Lai, Y.S..Lee, and D. Martin, ―Design of parallel inverters for smooth mode transfer microgrid applications,‖ IEEE trans. Power Eletron., vol. 25, no.1 pp. 6-15, Jan.2010.
[6] P. K. Hinga, T. Ohnishi, and T. Suzuki, ―A new PWM inverter for photovoltaic power generation system,‖ in Conf. Rec. IEEE Power Electron. Spec. Conf., 1994, pp. 391–395.
[7] Y. Cheng, C. Qian, M. L. Crow, S. Pekarek, and S. Atcitty, ―A comparison of diode-clamped and cascaded multilevel converters for a STATCOM with energy storage,‖ IEEE Trans. Ind. Electron., vol. 53, no. 5, pp. 1512– 1521, Oct. 2006.