Toggle Main Menu Toggle Search

Open Access padlockePrints

Three-phase soft-switching voltage source converters for motor drives. Part 2: Fundamental limitations and critical assessment

Lookup NU author(s): Dr Christopher Johnson, Professor Volker Pickert


Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


Fundamental limits to soft-switching converter performance are established by examining the detailed physical behaviour of bipolar power semiconductors. It is found that the soft-switched resonant transition time must be much longer than the semiconductor high-level carrier lifetime for effective reduction of switching losses. Constraints on PWM range and PWM resolution as a function of switching frequency are established for a range of soft-switching converter topologies and the standard hard-switched inverter. For quasi-resonant DC-link topologies, the degradation in PWM resolution causes low-frequency harmonics to be introduced into the output spectrum. Topology-specific features are used to form a comparative assessment of the principal classes of soft-switched converters. Resonant DC-link topologies are shown to produce the poorest output performance, although they offer the cheapest solution. Auxiliary resonant pole inverters can achieve levels of performance approaching those of the hard-switched topology, while retaining the benefits of soft-switching. It is concluded that the auxiliary commutated pole inverter offers the greatest potential for exploitation despite its relatively high capital cost. Modularization of the active devices and optimization of semiconductor design are identified as key objectives in the realization of an economically viable system.

Publication metadata

Author(s): Johnson CM, Pickert V

Publication type: Article

Publication status: Published

Journal: IEE Proceedings: Electric Power Applications

Year: 1999

Volume: 146

Issue: 2

Pages: 155-162

Print publication date: 01/03/1999

ISSN (print): 1350-2352

ISSN (electronic):

Publisher: The Institution of Engineering and Technology


DOI: 10.1049/ip-epa:19990300


Altmetrics provided by Altmetric