Innovative GTO Thyristor Based Switches Through Unity Gain Turn-Off

Simple item page
dc.contributor.authorLi, Yuxinen
dc.contributor.committeechairHuang, Alex Q.en
dc.contributor.committeememberNelson, Douglas J.en
dc.contributor.committeememberChen, Dan Y.en
dc.contributor.committeememberLai, Jih-Shengen
dc.contributor.committeememberBorojević, Dušanen
dc.contributor.departmentElectrical and Computer Engineeringen
dc.date.accessioned2011-08-22T19:04:14Zen
dc.date.adate2000-11-10en
dc.date.available2011-08-22T19:04:14Zen
dc.date.issued1997-09-22en
dc.date.rdate2001-11-10en
dc.date.sdate2000-10-04en
dc.description.abstractThe Gate Turn-Off (GTO) Thyristor has the best voltage blocking and current conducting capabilities among all known high power semiconductor devices. To improve its dynamic performances to meet the increased demand in high-performance high-power applications, a special driving technique, namely unity gain turn-off, is studied. Several innovative approaches, which realize this driving requirement, are proposed, analyzed and experimentally demonstrated in this dissertation. The Emitter Turn-Off Thyristor (ETO) is a new family of high power semiconductor devices that is suitable for megawatt power electronics application. ETOs with voltage and current ratings of 4.0~6.0 kV and 1.0~4.0 kA, have been developed and demonstrated. These power levels are the highest in silicon power devices and are comparable to those of the GTO. Compared to the conventional GTO, the ETO has a much shorter storage time, voltage controlled turn-off capability, and a much larger reverse biased safe operation area (RBSOA). These combined advantages make the ETO based power system simpler in terms of dv/dt snubber, di/dt snubber and over current protection, resulting in significant savings at the system level. Experimental and numerical simulation results that demonstrate the advantages of the ETO are presented. A new family of snubberless turn-off GTO, the Resonant Gate Commutated Thyristor (RGCT) is proposed and investigated. By using a transient high commutation voltage, the RGCT can achieve unity turn-off gain and snubberless turn-off capability even with a relatively high gate loop stray inductance. Therefore conventional GTOs with flexible gate lead can be used to achieve the state-of-the-art performance similar to that of the Integrated Gate Commutated Turn-Off thyristor (IGCT). Detailed current commutation analysis and experimental results are presented. A novel equivalent circuit model for the GTO under the unity gain turn-off is proposed. This model is composed of a step current source, which represents the open-base PNP turn-off behavior, in series with a diode that represents the GTO's gate-cathode junction. This equivalent circuit can be used to analyze the turn-off transient behavior of a system employing this GTO. A new mechanism that dominates the failure of the GTO under the unity gain turn-off condition is identified and analyzed. Innovative hybrid GTO-based devices all have significant gate lead stray inductance. During the turn-off transition, this stray inductor will interact with the turn-off voltage source, the junction capacitance of the GTO's gate-cathode, causing effective current injection into the GTO's emitter junction when the voltage on the device is already high. Design guidelines and solutions for different types of GTO-based hybrid devices are provided.en
dc.description.degreePh. D.en
dc.format.mediumETDen
dc.identifier.otheretd-10042000-14410005en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-10042000-14410005en
dc.identifier.urihttp://hdl.handle.net/10919/11237en
dc.publisherVirginia Techen
dc.relation.haspartYuxin_Li_Dissertation_Version3.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectgate-turn-offen
dc.subjectGTOen
dc.subjectETOen
dc.subjectthyristoren
dc.subjectsnubberlessen
dc.titleInnovative GTO Thyristor Based Switches Through Unity Gain Turn-Offen
dc.typeDissertationen
thesis.degree.disciplineElectrical and Computer Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Yuxin_Li_Dissertation_Version3.pdf
Size:
3.93 MB
Format:
Adobe Portable Document Format
Download

Collections

Doctoral Dissertations