A Dual Three-Level T-NPC Inverter for High-Power Traction Applications

• Published in: IEEE journal of emerging and selected topics in power electronics Vol. 4; no. 2; pp. 668 - 678
• Main Authors: Bhattacharya, Subhadeep, Mascarella, Diego, Joos, Geza, Cyr, Jean-Marc, Jianhong Xu
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.06.2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Capacitors; DC-AC power converter; DC-link capacitor balancing; dual; Electric potential; Insulated gate bipolar transistors; interleaved; Inverters; Modulation; Stator windings; Switches; Switching; T-type inverter; Topology; Traction; Voltage; Windings; T-type inverter; DC–AC power converter; dc-link capacitor balancing; interleaved; dual
• ISSN: 2168-6777; 2168-6785
• DOI: 10.1109/JESTPE.2016.2517819

This paper proposes a dual three-level, T-type, neutral-point clamped (T-NPC) inverter fed dual permanent magnet synchronous motor topology for low-voltage, high-power traction applications. The switching pulses of the T-NPC inverters are interleaved and controlled, such that they produce equal and opposite three-phase currents at their output. This maintains balanced dc-link voltages in steady-state and transient conditions, even with slight mismatches between two sets of three-phase loads. Thus, the proposed configuration decouples the modulation strategy from the capacitor balancing control. Simulation and experimental results demonstrate that in comparison to the conventional single T-NPC inverter, the proposed topology reduces dc-link capacitors' voltage deviation and current stress by more than 90% while avoiding additional switching instances to balance capacitor voltages.