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A new regenerative snubber circuit for large‐capacity three‐level GTO inverter systems
Author(s) -
Okayama Hideo,
Tsuchiya Taichiro,
Shimomura Yasuhito
Publication year - 1997
Publication title -
electrical engineering in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.136
H-Index - 28
eISSN - 1520-6416
pISSN - 0424-7760
DOI - 10.1002/(sici)1520-6416(19970730)120:2<41::aid-eej6>3.0.co;2-t
Subject(s) - snubber , inverter , electronic circuit , electrical engineering , transformer , electronic engineering , thyristor , gate turn off thyristor , engineering , voltage , materials science , capacitor , transistor , gate oxide
Increase in the capacity of GTOs has made remarkable progress in recent years. At present, 4.5‐kV, 4.0‐kA GTOs are commercially available, and 6.0‐kV, 6.0‐kA GTOs made from 6‐inch silicon wafers are appearing. The 6‐inch GTOs will be applied to our three‐level GTO inverter system. In order to apply GTOs to voltage‐source inverters, snubber circuits are necessary for limiting on the turn‐on di/dt and turn‐off dv/dt . To realize high efficiency of the system, regenerative snubber circuits are often applied. A conventional circuit applied to three‐level GTO inverters had the problem of long paths created for snubber circuits of the inner GTOs. Another circuit using a current transformer for recovering the energy trapped in the snubber circuits of the inner GTOs has been presented. In this paper, a new regenerative snubber circuit is proposed, which is more suitable for three‐level GTO inverter systems with many phase‐legs. By applying the snubber circuit, all snubber energy generated by each GTO switching can be regenerated to the dc link. In addition, high current turn‐off performance of both the inner and the outer GTOs is verified by several successful experimental results using 6‐inch 6.0‐kV, 6.0‐kA GTOs. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 120(2): 41–48, 1997