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Vol: 55(69) No: 2 / June 2010        

Analysis and DSP Implementation of Flat-Top Space-Vector Modulation
N. S. Preda
Technical University of Cluj-Napoca / Department of Electrical Drives and Robots, Cluj-Napoca, Romania, e-mail: nicolae.preda@edr.utcluj.ro
D. C. Rus
Technical University of Cluj-Napoca / Department of Electrical Drives and Robots, Cluj-Napoca, Romania, e-mail: dan_claudiu_rus@yahoo.com
I. I. Incze
Technical University of Cluj-Napoca / Department of Electrical Drives and Robots, Cluj-Napoca, Romania, e-mail: ioan.incze@edr.utcluj.ro
Maria Imecs
Technical University of Cluj-Napoca / Department of Electrical Drives and Robots, Cluj-Napoca, Romania, e-mail: imecs@edr.utcluj.ro
Cs. Szabó
Technical University of Cluj-Napoca / Department of Electrical Drives and Robots, Cluj-Napoca, Romania, e-mail: csaba.szabo@edr.utcluj.ro


Keywords: Flat-Top, space-phasor, modulation, DSP.

Abstract
The paper focuses on the four variants of flat-top (discontinuous) space-vector (space-phasor) modulation method, its advantages over the simple suboptimal technique and the implementation steps on a TMS320F2812 fixed-point digital signal processor using MATLAB’s Simulink® and the eZdsp development board. The simulation results show the improvements brought by the Flat-Top techniques: less commutations, even inside a sampling period, the ability to choose a Flat-Top method in correlation with the character of the inverter’s load in order to reduce furthermore the commutation losses. A harmonic analysis and the simulation of an induction motor fed by a voltage-source inverter controlled with these modulation methods were performed in order to compare the performance of flat-top methods against the simple suboptimal and the classical sinusoidal carrier-wave modulation procedure. The implementation design of these flat-fop techniques is improved by computing the position of the reference phasor without any trigonometric function, by using p.u. values for the on-times of basic vectors and by using the DC link voltage value, which can be compensated in case of the voltage ripples.

References
[1] J. Holz, “Pulsewidth Modulation for Electronic Power Conversion”, Proceedings of the IEEE, Vol. 82, No.4, pp. 1194-1214, Aug. 1994.
[2] Y. S. Kung and P.G. Huang, “High performance position controller for PMSM drives based on TMS320F2812 DSP”, Proceeding of the 2004 IEEE International Conference on Control Applications, Taipei, Taiwan, pp. 290–295, Sept 2-4, 2004.
[3] D. O. Neacsu, “Space vector modulation – An introduction,” IECON\'01 The 27th Annual Conference of the IEEE Industrial Electronics Society, Denver, CO, USA, Vol. 3, pp. 1583 – 1592. 29 Nov.-2 Dec. 2001.
[4] Maria Imecs, “Open-loop voltage-controlled PWM procedures,” Proceedings of the 3rd ELECTROMOTION International Conference, Patras, Greece, Volume I, , pp. 285-290, Jul 1999.
[5] Maria Imecs, “Synthesis about pulse modulation methods in electrical drives,” Part 1 and 2, Proceedings of the National Conference on Electrical Drives CNAE, Craiova, Romania, pp. 19-33, 8-9 Oct 1998, Part 3. Acta Universitatis CIBIENSIS, Vol. XLI Technical series, H. Electrical Engineering and Electronics, \"Lucian Blaga\" University of Sibiu, pp.15-26, 25-26 Nov 1999.
[6] A. Kelemen, Maria Imecs, “Vector Control of AC Drives”. Volume 1: OMIKK, Budapest, 1991.
[7] F. Ionescu, D. Floricau, S. Nitu, J. P. Six, P. Delarue, C. Bogus: Electronică de putere. Convertoare statice. (in Romanian), Editura Tehnică, Bucharest, 1998.
[8] J. W. Kolar, H. Ertl, F. C. Zach, “Influence of the Modulation Method on the Conduction and Switching Losses of a PWM Converter System”. IEEE Transaction. Industrial Applications, Vol.27, No.6, pp. 1063-1075, Nov/Dec 1991.
[9] J. W. Kolar, H. Ertl, F. C. Zach, “Minimizing the Current Harmonics RMS Value of Three-Phase PWM Converter Systems by Optimal and Suboptimal of Three-Phase Between Continuous and Discontinuous Modulation”. IEEE Power Electronics Specialists Conference, Boston, pp. 372-38, June 1991.
[10] J. Holz, “Pulsewidth modulation – a survey”, IEEE Trans. Ind.Electron., Vol. 39, No. 5, pp. 410-420, Oct. 1992.
[11] Jennifer Vining, “Harmonic Effects of Space Vector Modulation on Induction Motor Performance”, Dept. of El. And Computer Engineering, 1415 Engineering Drive.
[12] A. Mehrizi-Sani and S. Filizadeh, “An optimized space vector modulation sequence for improved harmonic performance,” IEEE Trans. Ind. Electron., accepted for publication.
[13] A. Mehrizi-Sani, S. Filinzadeh, P. L. Wilson, “Harmonic and loss analysis of space-vector modulated converters”, in Proc. Int. Conf. Power Syst. Transients (IPST07), Lyon, France, June 4-7, 2007.