Voltage stress on induction motors in medium-voltage (2300-6900-V) PWM GTO CSI drives

Author

Wu, Bin ; Dewinter, Frank A.

Author_Institution

Dept. of Electr. Eng., Ryerson Polytech. Inst., Toronto, Ont., Canada

Volume

12

Issue

2

fYear

1997

fDate

3/1/1997 12:00:00 AM

Firstpage

213

Lastpage

220

Abstract

In order to reduce the cost and improve the efficiency of medium-voltage induction motor drives, it is desirable that no power transformers be used. The GTO current source inverter (CSI) drive can achieve this requirement. However, the transformerless design of the drive may introduce a high-voltage stress on motor windings, which may deteriorate the motor insulation life. In this paper, the line-to-ground and neutral-to-ground voltages of the motor fed by the GTO CSI are investigated. It is demonstrated that the maximum line-to-ground voltage applied to the motor could be twice as high as the motor-rated phase voltage. Computer simulation and experimental results from a 4000 V, 1250 HP drive are given to verify the theoretical analysis. The effects of DC link choke arrangement on the motor voltage stress are also discussed. This paper provides a valuable design guidance for the insulation of medium-voltage motors used in the GTO CSI drives

Keywords

PWM invertors; digital simulation; induction motor drives; machine windings; power engineering computing; simulation; thyristor convertors; thyristor motor drives; 1250 hp; 2300 to 6900 V; DC link choke arrangement; GTO current source inverter; computer simulation; efficiency improvement; high-voltage stress; induction motors; line-to-ground voltages; medium-voltage PWM GTO CSI drives; motor-rated phase voltage; neutral-to-ground voltages; transformerless design; voltage stress; Computer simulation; Costs; Induction motor drives; Induction motors; Insulation life; Inverters; Medium voltage; Power transformer insulation; Power transformers; Stress;

fLanguage

English

Journal_Title

Power Electronics, IEEE Transactions on

Publisher

ieee

ISSN

0885-8993

Type

jour

DOI

10.1109/63.558730

Filename

558730