Voltage Balancing And Commutation Suppression In Symmetrical Cascade Multilevel Converters For Power Quality Applications

This paper presents a modulation strategy for symmetrical cascaded multilevel converters that simultaneously balances the individual DC voltages and reduces switching losses by eliminating redundant or unnecessary commutations. The voltage regulation is based on a 1-bit digital signal indicating whether the DC link voltage of each H-bridge is above or below the set point. The system command identifies commutations that can be suppressed without causing output voltage distortion, thus reducing converter losses. The voltage balancing is reached by postponing each switching commutation for a short lapse of time. Simulation and experimental results for an active filter application validate the proposed methods. © 1982-2012 IEEE.611159966003Lai, J.-S., Peng, F.Z., Multilevel converters - A new breed of power converters (1996) IEEE Transactions on Industry Applications, 32 (3), pp. 509-517. , PII S0093999496020920Rodríguez, J., Lai, J.S., Peng, F.Z., Multilevel inverters: A survey of topologies, control and applications (2002) IEEE Trans. Ind. Electron., 49 (4), pp. 724-738. , AugKouro, S., Malinowski, M., Gopakumar, K., Pou, J., Franquelo, L.G., Wu, B., Rodriguez, J., Leon, J.I., Recent advances and industrial applications of multilevel converters (2010) IEEE Trans. Ind. Electron., 57 (8), pp. 2533-2580. , AugRodríguez, J., Franquelo, L.G., Kouro, S., Leon, J.I., Portillo, R., Prats, M., Perez, M., Multilevel converters: An enabling technology for high-power applications (2009) Proc. IEEE, 97 (11), pp. 1786-1817. , NovRodriguez, J., Bernet, S., Wu, B., Pontt, J.O., Kouro, S., Multilevel voltage-source-converter topologies for industrial medium-voltage drives (2007) IEEE Transactions on Industrial Electronics, 54 (6), pp. 2930-2945. , DOI 10.1109/TIE.2007.907044Manjrekar, M.D., Steimer, P.K., Lipo, T.A., A hybrid multilevel power conversion system: A competitive solution for high-power applications (2000) IEEE Trans. Ind. Appl., 36 (3), pp. 834-841. , May/JunRech, C., Pinheiro, J.R., Hybrid multilevel converters: Unified analysis and design considerations (2007) IEEE Transactions on Industrial Electronics, 54 (2), pp. 1092-1104. , DOI 10.1109/TIE.2007.892255Lu, S., Marieethoz, S., Corzine, K.A., Asymmetrical cascade multilevel converters with noninteger or dynamically changing DC voltage ratios: Concepts and modulation techniques (2010) IEEE Trans. Ind. Electron., 57 (7), pp. 2411-2418. , JulSano, K., Takasaki, M., A transformerless D-STATCOM based on a multivoltage cascade converter Requiring no DC sources (2012) IEEE Trans. Power Electron., 27 (6), pp. 2783-2795. , JunEbrahimi, J., Babaei, E., Gharehpetian, G.B., A new multilevel converter topology with reduced number of power electronic components (2012) IEEE Trans. Ind. Electron., 59 (2), pp. 655-667. , FebMalinowski, M., Gopakumar, K., Rodríguez, J., Perez, M.A., A survey on cascaded multilevel inverters (2010) IEEE Trans. Ind. Electron., 57 (7), pp. 2197-2206. , JulCarnielutti, F., Pinheiro, H., Rech, C., Generalized carrier-based modulation strategy for cascaded multilevel converters operating under fault conditions (2012) IEEE Trans. Ind. Electron., 59 (2), pp. 679-689. , FebLezana, P., Pou, J., Meynard, T., Rodriguez, J., Ceballos, S., Richardeau, F., Survey on fault operation on multilevel inverters (2010) IEEE Trans. Ind. Electron., 57 (7), pp. 2207-2218. , JulIlves, K., Antonopoulos, A., Norrga, S., Nee, H.P., A new modulation method for the modular multilevel converter allowing fundamental switching frequency (2012) IEEE Trans. Power Electron., 27 (8), pp. 3482-3494. , AugAllebrod, S., Hamerski, R., Marquardt, R., New transformerless, scalable modular multilevel converters for HVDC-transmission (2008) In Proc, pp. 174-179. , IEEE Power Electron. Spec. ConfFlourentzou, N., Agelidis, V.G., Demetriades, G.D., VSC-based HVDC power transmission systems: An overview (2009) IEEE Trans. Power Electron., 24 (3), pp. 592-602. , MarSaeedifard, M., Iravani, R., Dynamic performance of a modular multilevel back-to-back HVDC system (2010) IEEE Trans. Power Del., 25 (4), pp. 2903-2912. , OctHiller, M., Krug, D., Sommer, R., Rohner, S., A new highly modular medium voltage converter topology for industrial drive applications (2009) Proc. Eur. Conf. Power Electron. Appl., pp. 1-10Hagiwara, M., Nishimura, K., Akagi, H., A medium-voltage motor drive with a modular multilevel PWM inverter (2010) IEEE Trans. Power Electron., 25 (7), pp. 1786-1799. , JulKorn, A.J., Winkelnkemper, M., Steimer, P., Low output frequency operation of the modular multi-level converter In Proc, 2010, pp. 3993-3997. , IEEE Energy Convers. Congr. ExpoGovindaraju, C., Baskaran, K., Efficient sequential switching hybrid-modulation techniques for cascaded multilevel inverters (2011) IEEE Trans. Power Electron., 26 (6), pp. 1639-1648. , JunNajafi, E., Yatim, A.H.M., Design and implementation of a new multilevel inverter topology (2012) IEEE Trans. Ind. Electron., 59 (11), pp. 4148-4154. , NovGao, C., Jiang, X., Li, Y., Chen, Z., Liu, J., A DC-link voltage self-balance method for a diode-clamped modular multilevel converter with minimum number of voltage sensors (2013) IEEE Trans. Power Electron., 28 (5), pp. 2125-2139. , MayHagiwara, M., Akagi, H., Control and experiment of pulsewidth-modulated modular multilevel converters (2009) IEEE Trans. Power Electron., 24 (7), pp. 1737-1746. , JulRohner, S., Bernet, S., Hiller, M., Sommer, R., Modulation, losses, and semiconductor requirements of modular multilevel converters (2010) IEEE Trans. Ind. Electron., 57 (8), pp. 2633-2642. , AugAlvarenga, M.B., Pomilio, J.A., Analysis of pulse suppression in PWM modulation for symmetric cascaded multilevel inverters (2011) Proc. IEEE 37th IECON/IECON, pp. 4654-4659. , NovSamra, A.-H., Teshome, A., Characteristics and noncharacteristic harmonic in AC Power System Operation (1991) Proc. IEEE 34th Midwest Symp. Circuits Syst, 2, pp. 645-648. , MayGunther, E.W., Interharmonics in power systems (2001) In Proc. Power Eng. Soc. Summer Meet, 2, pp. 813-817. , Jul(1997), http://grouper.ieee.org/groups/harmonic/iharm/ihfinal.pdf, IEEE Interharmonic Task Force, Cigré 36.05/CIRED 2 CC02 Voltage Quality Working Group, Interharmonics in Power Systems [Online]Czarnecki, L.S., Effect of minor harmonics on the performance of resonant harmonic filters in distribution systems (1997) IEE Proceedings: Electric Power Applications, 144 (5), pp. 349-356Peeran, S.M., Cascadden, C.W.P., Application, design, and specification of harmonic filters for variable frequency drives (1995) IEEE Trans. Ind. Appl., 31 (4), pp. 841-847. , Jul./AugGunther, E.W., Interharmonics-recommended updates to IEEE 519 (2002) Proc. Power Eng. Soc. Summer Meet, 2, pp. 950-954. , Ju