Three-phase multilevel inverter configuration for open-winding high power application

Abstract

This paper work exploits a new dual openwinding three-phase multilevel inverter configuration suitable for high power medium-voltage applications. Modular structure comprised of standard three-phase voltage source inverter (VSI) along with one additional bi-directional semiconductor device (MOSFET/IGBT) per phase and two capacitors with neutral point. Hence, introduces the additional voltage levels in each phase of the VSI. Further, this paper developed a modified single carrier five-level modulation (MSCFM) scheme in such way to overcome the complexity of standard space vector modulations, ready for implementation purpose. Proposed dual-inverter configuration generates multilevel outputs with benefit includes reduced THD and dv/dt in comparison to other dual-inverter topologies. Complete model of the multilevel ac drive is developed with simple MSCFM modulation in Matlab/PLECs numerical software. Preliminary results are provided in this paper confirm the suitability of investigation for real implementation.

Reconfiguration of a Multilevel Inverter with Trapezoidal Pulse Width Modulation

“…The first category needs pre-calculated switching angles for generating the PWM signals [23]. The space vector method will be very complicated for more than five output voltage levels due to increases in switching states [24]. The carrier-based PWM methods are simple to use when the number of output levels is more than five [25,26].…”

A novel five-level optimized carrier multilevel PWM quad-inverter six-phase AC drive

“…In such cases, the conventional three-phase dual inverters are the good solution. The two three-phase VSIs (two-level) are connected each at the open-ends of windings [14][15][16][17][31][32][33]. Moreover, the potential difference between two single inverter's leg potential constitutes the output voltages.…”

“…Also, the benefits are compromised to classical MLI's. Output qualities are assured in additional by common-mode currents cancellation are carried out by the PWM techniques or by deliberately kept isolated dc sources [13][14][15][16][17][31][32][33]. Dual inverter with z-source impedance network in the dc link side configured and addressed for buck/boost the output voltages [31] with limited common-mode components and for grid integration with/without isolation transformer [32].…”

“…1 [14][15][16][17]33]. The structure suits for medium power (lowvoltage/high-current) applications of ac tractions, electrical vehicle and MEA propulsion systems.…”

“…The structure suits for medium power (lowvoltage/high-current) applications of ac tractions, electrical vehicle and MEA propulsion systems. Proposed single carrier modulation algorithm (independent modulation) has the capability to use each VSI as a standard five-level MLI's [33]. Modular power converter consists of four standard two-level VSIs and additionally each phase of VSIs as one bi-directional (IGBT) switch and links the neutral through two capacitor.…”