An active circuit for cancellation of common-mode voltage generated by a PWM inverter

This paper proposes an active common-noise canceler (ACC) that is capable of eliminating the common-mode voltage produced by a pulsewidth modulation (PWM) inverter. An emitter follower using complementary transistors and a common-mode transformer are incorporated into the ACC, the design method of which is also presented in detail. Experiments using a prototype ACC, whose design and construction are discussed in this paper, verify its viability and effectiveness in eliminating common-mode voltage in a 3.7 kW induction motor drive using an insulated gate bipolar transistor (IGBT) inverter. Some experimental results show that the ACC makes significant contributions to reducing a ground current and a conducted electromagnetic interference (EMI). In addition, the ACC can prevent an electric shock on a nongrounded motor frame and can suppress motor shaft voltage

Digital Object Identifier: 10.1109/63.712285
Published with permission from the copyright holder. This is the institute's copy, as published in Power Electronics, IEEE Transactions on, Sept. 1998, Volume 13, Issue 5, Pages 835-841.
Publisher URL:http://dx.doi.org/10.1109/63.712285
Copyright © 1998 IEEE. All rights reserved.