A new control strategy to improve the performance of a PWM AC to DC converter under unbalanced operating conditions

Author

Enjeti, Prasad N. ; Choudhury, Shamin A.

Author_Institution

Dept. of Electr. Eng., Texas A&M Univ., College Station, TX, USA

Volume

8

Issue

4

fYear

1993

fDate

10/1/1993 12:00:00 AM

Firstpage

493

Lastpage

500

Abstract

Abnormal harmonics of significant magnitude are generated at the output and input terminals of a PWM (pulse-width-modulated) AC-to-DC power converter under unbalanced operating conditions. A new control strategy is presented to selectively cancel the generated lower-order abnormal harmonics at the output and input terminals and thereby to preserve the high-performance features of a PWM AC-to-DC power converter. The proposed technique essentially involves computing the sequence components of the unbalanced input supply and suitably counter-unbalances the PWM gating signals of the power converter switches to cancel the generated abnormal harmonics. The technique is essentially a feedforward approach and is suitable for higher-power GTO (gate turn-off thyristor) type PWM AC-to-DC power converters. A procedure for implementing this technique in real time is discussed. Selected results are verified experimentally on a prototype PWM AC-to-DC power converter

Keywords

harmonics; power convertors; pulse width modulation; thyristor applications; voltage control; AC-to-DC power converter; GTO; PWM; gating signals; harmonics; performance; real time; unbalanced operating conditions; voltage control; AC generators; Analog-digital conversion; DC generators; Power generation; Power system harmonics; Pulse generation; Pulse width modulation; Pulse width modulation converters; Switching converters; Thyristors;

fLanguage

English

Journal_Title

Power Electronics, IEEE Transactions on

Publisher

ieee

ISSN

0885-8993

Type

jour

DOI

10.1109/63.261020

Filename

261020