Optimal Selection of the Average Capacitor Voltage for Variable-Speed Drives With Modular Multilevel Converters

Variable-speed drives have reduced voltage requirements when operating below the base speed. In a modular-multilevel-converter-based (M2C-based) motor drive, it is then possible to operate with reduced voltage in the submodule capacitors, than at the base speed. In this sense, a greater capacitor-vo...

Full description

Saved in:
Bibliographic Details
Published in:IEEE transactions on power electronics Vol. 30; no. 1; pp. 227 - 234
Main Authors: Antonopoulos, Antonios, Angquist, Lennart, Harnefors, Lennart, Nee, Hans-Peter
Format: Journal Article
Language:English
Published: New York IEEE 01-01-2015
The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Subjects:
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Variable-speed drives have reduced voltage requirements when operating below the base speed. In a modular-multilevel-converter-based (M2C-based) motor drive, it is then possible to operate with reduced voltage in the submodule capacitors, than at the base speed. In this sense, a greater capacitor-voltage ripple can be accommodated, without exceeding the maximum peak-capacitor voltage. This paper presents an analytical investigation for the optimal selection of the average capacitor voltage for M2Cs, when the motor is operating with rated torque, below the base speed. This method does not require any power exchange between the converter arms, so it keeps the conduction losses at the minimum level. Additionally, the method decreases the switching losses, due to the decreased capacitor-voltage level. The overall ratings of the converter remain the same as in the base-speed operation. It is shown that this method can be applied at a speed range between the base speed and down to approximately one third of it, i.e., an operating range that covers the requirements for typical pump- and fan-type applications. The results obtained from the analytical investigation are experimentally verified on a down-scaled laboratory prototype M2C.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:0885-8993
1941-0107
1941-0107
DOI:10.1109/TPEL.2014.2316273