Evaluation of IGBT multilevel converters for transformerless traction applications

Author

Dieckerhoff, Sibylle ; Bernet, Steffen ; Krug, Dietmar

Author_Institution

Tech. Univ. of Berlin, Germany

Volume

4

fYear

2003

fDate

15-19 June 2003

Firstpage

1757

Abstract

The low-frequency line transformer in todays ac rail vehicles suffers from poor efficiency and high weight. Future traction drives may operate directly from the mains without this transformer. A feasible concept for a transformerless drive system consists of series connected medium voltage converters applying modern HV-IGBTs. In a first design step, the switching characteristics and losses of the new 6.5 kV IGBTs are compared to 3.3 kV and 4.5 kV IGBTs which are already commercially in use for some time. Based on the considered HV-IGBTs, the paper analyzes the properties of multilevel converters and evaluates their applicability to the transformerless system. This includes a loss analysis, reliability aspects and harmonic spectra. Due to the reduced effort for additional passive components, the 3-leveI NPC converter turns out to be a reasonable solution to realize line and motor converter modules.

Keywords

AC motor drives; electric locomotives; insulated gate bipolar transistors; power convertors; railway electrification; semiconductor device reliability; spectra; traction motor drives; 3-leveI NPC converter; 3.3 kV; 4.5 kV; 6.5 kV; HV-IGBTs; IGBT multilevel converter; ac rail vehicle; harmonic spectra; line converter module; loss analysis; low-frequency line transformer; mains; motor converter module; multilevel converter; passive component; reliability; series connected medium voltage converter; switching characteristics; switching loss; traction drive; transformerless drive system; transformerless traction applications; Buffer layers; Insulated gate bipolar transistors; Low voltage; Resistors; Semiconductor diodes; Semiconductor optical amplifiers; Switches; Tail; Thermal conductivity; Traction motors;

fLanguage

English

Publisher

ieee

Conference_Titel

Power Electronics Specialist Conference, 2003. PESC '03. 2003 IEEE 34th Annual

ISSN

0275-9306

Print_ISBN

0-7803-7754-0

Type

conf

DOI

10.1109/PESC.2003.1217721

Filename

1217721