### A Five-Level Current-Source Inverter for Grid-Connected or High-Power Three-Phase Wound-Field Synchronous Motor Drives

#### Abstract

Simple converter structure, inherent short-circuit protection and regenerative capability are the most important advantages of current-source inverters (CSI’s) which have made them suitable for medium-voltage high-power drives. Usually in grid-connected gas turbine generators or pumped storage hydro power plants, efficient and reliable current-source load-commutated inverters (LCI’s) with thyristor switches are employed. Also, this type of CSI is widely used in very large drives with power ratings of tens of megawatts to supply wound-field synchronous motors (WFSM’s). However, LCI’s suffer from some disadvantages such as large torque pulsations, poor power factor, and start-up criticalities. In this paper, a novel multilevel-based CSI is proposed. The proposed converter consists of one LCI and one CSI bridge with self-turn-off switches along with a voltage clamping circuit. The CSI switches are forced commutated; hence, a voltage clamping circuit is employed to limit voltage spikes caused by current variations in inductive paths during commutation transients. Drastic reduction in harmonic distortion of stator current and improved fundamental power factor are achieved by the proposed topology. In addition, torque pulsations are reduced remarkably for normal and starting operating conditions. Comprehensive analysis of the proposed structure is presented and the design of converter components is elaborated.

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B. Wu, J. Pontt, J. Rodríguez, S. Bernet, S. Kouro, “Current-source converter and cycloconverter topologies for industrial medium-voltage drives”, IEEE Trans. Ind. Electron., Vol. 55, No. 7, pp. 2786–2797, 2008

Q. Wei, B. Wu, D. Xu, N. R. Zargari, “A natural-sampling-based SVM scheme for current source converter with superior low-order harmonics performance”, IEEE Trans. Power Electron., Vol. 31, No. 9, pp. 6144-6154, 2016

Y. Zhang, Y. W. Li, “Investigation and suppression of harmonics interaction in high-power PWM current-source motor drives”, IEEE Trans. Power Electron., Vol. 30, No. 2, pp. 668-679, 2015

B. Wu, S. B. Dewan, G. R. Slemon, “PWM-CSI inverter for induction motor drives”, IEEE Trans. Ind. Appl., Vol. 28, No. 1, pp. 64-71, 1992

H. Mok, S. Sul, M. Park, “A load commutated inverter-fed induction motor drive system using a novel dc-side commutation circuit”, IEEE Trans. Ind. Appl., Vol. 30, No. 3, pp. 736-745, 1994

E. Levi, “Multiphase electric machines for variable-speed applications”, IEEE Trans. Ind. Electron., Vol. 55, No. 5, pp. 1893–1909, 2008

H. Stemmler, “High-power industrial drives”, Proc. IEEE, Vol. 82, Vo. 8, pp. 1266–1286, 1994

S. Mohamadian, A. Tessarolo, S. Castellan, A. Shoulaie, “Steady-state simulation of LCI-fed synchronous motor drives through a computationally-efficient algebraic method”, IEEE Trans. Power Electron., Vol. 32, No. 1, pp. 452–470, 2016

T. J. Besselmann, S. Van de Moortel, S. Almér, P. Jörg, H. J. Ferreau, “Model predictive control in the multi-megawatt range”, IEEE Trans. Ind. Electron., Vol. 63, No. 7, pp. 4641-4648, 2016

N. Sivakumar, D. Das, N. P. Padhy, “Variable speed operation of reversible pump-turbines at Kadamparai pumped storage plant – A case study”, Energy Convers. and Manage., Vol 78, pp. 96-104, 2014

F. Wang, J. Jiang, “A novel static frequency converter based on multilevel cascaded H-bridge used for the startup of synchronous motor in pumped-storage power station”, Energy Convers. and Manage., Vol 52, pp. 2085-2091, 2011

J. Song-Manguelle, C. Sihler, S. Schramm, “A general approach of damping torsional resonance modes in multi-megawatt applications”, IEEE Trans. Ind. Appl., Vol. 47, No. 3, pp. 1390–1399, 2011

K. S. Smith, L. Ran, “Torsional resonance risk management in islanded industrial power systems supplying large VFDs”, IEEE Trans. Ind. Appl., Vol. 44, No. 6, pp. 1841-1850, 2008

S. Schramm, C. Sihler, J. Song-Manguelle, P. Rotondo, “Damping torsional inter-harmonic effects of large drives”, IEEE Trans. Power Electron., Vol. 25, No. 4, pp. 1090–1098, 2010

J. R. Rodriguez, J. Pontt, P. Newman, R. Musalem, H. Miranda, L. Moran, “Technical evaluation and practical experience of high-power grinding mill drives in mining applications”, IEEE Trans. Ind. Appl., Vol. 41, No. 3, pp. 866–874, 2005

A. Tessarolo, S. Castellan, R. Menis, G. Ferrari, “On the modeling of commutation transients in split-phase synchronous motors supplied by multiple load-commutated inverters”, IEEE Trans. Ind. Electron., Vol. 57, No. 1, pp. 35–43, 2010

B. Singh, S. Singh,and S. P. H. Chender, “Harmonic mitigation in LCI-fed synchronous motor drives”, IEEE Trans. Energy Convers., Vol. 25, No. 2, pp. 369–380, 2010

S. Mohamadian, A. Tessarolo, A. Shoulaie, “Design of an efficient starting circuit for LCI-fed synchronous motor drives”, 5th Annual International Power Electronics, Drive Systems and Technologies Conference (PEDSTC), pp. 31-36, February, 2014

B. K. Bose, Modern power electronics and AC drives. Prentice-Hall PTR, Upper Saddle River, NJ, 2002

D. R. Grafham, F. B. Golden, SCR Manual, 6th edition. General Electric Company, Syracruse, NY, 1979

G. Seguier, F. Labrique, Power Electronic Converters, DC-AC Conversion. Springer-verlag, 1993

S. Kwak, H. A. Toliyat, “A current source inverter with advanced external circuit and control method”, IEEE Trans. Ind. Appl., Vol. 42, No. 6, pp. 1496-1507, 2008

S. Mohamadian, A. Tessarolo, A. Shoulaie, “Field oriented control of LCI-fed WFSM drives in stator flux reference frame”, 5th Annual International Power Electronics, Drive Systems and Technologies Conference (PEDSTC), pp. 19-24, February, 2014

C. M. Ong, Dynamic Simulation of Electric Machinery, Prentice-Hall PTR, Upper Saddle River, NJ, 1998.

S. Kwak, H. A. Toliyat, “Multilevel converter topology using two types of current-source inverters”, IEEE Trans. Ind. Appl., Vol. 42, No. 6, pp. 1558-1564, 2006

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