A novel single-phase multi-level inverter topology based on bridge-type connected sources with enhanced number of levels per number of devices

Document Type : Original Article


Sahand University of Technology


This paper proposes a developed basic Multi-Level Inverter that is commercially suited for higher number of levels. The suggested topology can produce larger ratios of steps per DC sources, switches, gate-driver circuits and total devices than previous structures. The increased levels of suggested topology has led to low THD and better power quality. Accordingly, the output-side filter can be removed or its size can be reduced. The proposed topology doesn’t employ H-bridge to produce negative levels. So, the total voltage stress on switches is reduced in great extent. All the aforementioned properties make the suggested topology a compact, light and cheaper structure. Also, the suitability for supplying resistive-inductive (R-L) loads is another merit of suggested topology. Since the magnitude of DC sources influences the number of levels, three different scenarios have been considered for selecting magnitude of DC sources in basic topology. Then, the switching states, key parameters and blocking voltage on switches of suggested basic topology have been presented for each scenario. In the following, the generalized topology have been proposed that is consisted of cascaded basic units. Then, a generalized methodology has been suggested for selecting magnitude of DC sources in generalized topology to minimize redundant switching states and maximize number of voltage levels. To verify properties of suggested topology, it has been compared with similar novel structures. Also, to check correct performance of suggested topology, its basic version has been simulated in PSCAD/EMTDC software. The comparison and simulation outcomes certify advantages and correct operation of proposed topology.


Main Subjects

[1] M. Vijeh, M. Rezanejad, E. Samadaei, and K. Bertilsson, "A General Review of Multilevel Inverters Based on Main Submodules: Structural Point of View," IEEE Transactions on Power Electronics, vol. 34, no. 10, pp. 9479-9502, 2019.
[2] A. Nami, J. Liang, F. Dijkhuizen, and G. D. Demetriades, "Modular multilevel converters for HVDC applications: Review on converter cells and functionalities," IEEE Transactions on Power Electronics, vol. 30, pp. 18-36, 2015.
[3] A. A. Gandomi, S. Saeidabadi, S. H. Hosseini, E. Babaei, and Y. A. Gandomi, "Flexible transformer-based multilevel inverter topologies," IET Power Electronics, vol. 12, pp. 578-587, 2018.
[4] F. Esmaeili and K. Varesi, "A Modified Single-Phase Multi-Level Inverter with Increased Number of Steps," Iranian Conference on Renewable Energy & Distributed Generation (ICREDG), Tehran, Iran, 2019.
[5] K. K. Gupta and P. Bhatnagar, "Multilevel inverters: conventional and emerging topologies and their control," Academic Press, 2017.
[6] S. S. Lee, "Single-Stage Switched-Capacitor Module (S 3 CM) Topology for Cascaded Multilevel Inverter," IEEE Transactions on Power Electronics, vol. 33, pp. 8204-8207, 2018.
[7] S. Shi, X. Wang, S. Zheng, Y. Zhang, and D. Lu, "A New Diode-Clamped Multilevel Inverter with Balance Voltages of DC Capacitors," IEEE Transactions on Energy Conversion, vol. 33, no. 4, pp. 2220-2228, 2018.
[8] A. A. Gandomi, S. Saeidabadi, and S. H. Hosseini, "A high step up flying capacitor inverter with the voltage balancing control method," Power Electronics, Drive Systems & Technologies Conference (PEDSTC), pp. 55-60, 2017.
[9] A. A. Gandomi, K. Varesi, and S. H. Hosseini, "Control strategy applied on double flying capacitor multi-cell inverter for increasing number of generated voltage levels," IET Power Electronics, vol. 8, pp. 887-897, 2015.
[10] K. Varesi, M. Karimi, and P. Kargar, "A New Cascaded 35-Level Inverter with Reduced Switch Count," Iranian Conference on Renewable Energy & Distributed Generation (ICREDG), Tehran, Iran, 2019.
[11] K. Varesi, M. Karimi, and P. Kargar, "A new basic step-up cascaded 35-level topology extendable to higher number of levels," Power Electronics, Drives Systems and Technologies Conference (PEDSTC), pp. 1-6, 2019.
[12] R. S. Alishah, D. Nazarpour, S. H. Hosseini, and M. Sabahi, "Reduction of Power Electronic Elements in Multilevel Converters Using a New Cascade Structure," IEEE Transactions on Industrial Electronics, vol. 62, pp. 256-269, 2015.
[13] S. H. Hosseini, K. Varesi, J. F. Ardashir, A. A. Gandomi, and S. Saeidabadi, "An attempt to improve output voltage quality of developed multi-level inverter topology by increasing the number of levels," International Conference on Electrical and Electronics Engineering (ELECO), pp. 665-669, 2015.
[14] E. Babaei, C. Buccella, and C. Cecati, "New 8-Level Basic Structure for Cascaded Multilevel Inverters with Reduced Number of Switches and DC Voltage Sources," Journal of Circuits, Systems and Computers, vol. 28, p. 1950038, 2019.
[15] S. S. Lee, M. Sidorov, N. R. N. Idris, and Y. E. Heng, "A Symmetrical Cascaded Compact-Module Multilevel Inverter (CCM-MLI) With Pulsewidth Modulation," IEEE Transactions on Industrial Electronics, vol. 65, pp. 4631-4639, 2018.
[16] E. Babaei, S. Laali, and Z. Bayat, "A single-phase cascaded multilevel inverter based on a new basic unit with reduced number of power switches," IEEE Transactions on Industrial Electronics, vol. 62, pp. 922-929, 2015.
[17] E. Samadaei, S. Gholamian, A. Sheikholeslami, and J. Adabi, "An Envelope Type (E-Type) Module: Asymmetric Multilevel Inverters With Reduced Components," IEEE Transactions on Industrial Electronics, vol. 63, no. 11, pp. 7148-7156, 2016.
[18] S. Sabyasachi, V. B. Borghate, and S. K. Maddugari, "A 21-Level Bipolar Single-Phase Modular Multilevel Inverter," Journal of Circuits, Systems and Computers, (In Press), 2019.
[19] R. S. Alishah, S. H. Hosseini, E. Babaei, M. Sabahi, and A. Z. Gharehkoushan, "Optimal design of new cascade multilevel converter topology based on series connection of extended sub-multilevel units," IET Power Electronics, vol. 9, no. 7, pp. 1341-1349, 2016.
[20] E. Babaei and S. H. Hosseini, "New cascaded multilevel inverter topology with minimum number of switches," Energy Conversion and Management, vol. 50, pp. 2761-2767, 2009.