Research Of Current-sharing Of DC Breaker By Paralleled IGBT

High-current DC switches in pulsed power technology have very important andvariable applications. Now available high-current switches are mechanical switch，vacuumswitch，blasting switch，semiconductor switch，etc. According to their current level and theaction time these breakers are used in different work situations. From solid semiconductorswitch came out in the1950s，a sole solid switch’s capacity of voltage and current havelargely been developed due to the advancement of power semiconductor technics.So the useof multiple solid switches in series or in parallel to product high-voltage or high-current DCswitches have been large degree of research and application.This article makes use of IGBT contemporarily the most popular power semiconductordevices to achieve high-current DC switches in parallel. Firstly，the author diligentlyinvestigates applications and all current-sharing methods of paralleled IGBT at home andabroad，such as small resistor or choke coil in series in branches、Gate-resistor adjusting、feedback control of Gate-Emitter voltage、feedback regulation of trigger’s edge. Secondly，by a more comprehensive studies of the device physics、 electrical characteristics anddevice-drivers and their protection means，the author propose an Engineering analysisof expression from research of device expert. On the basis of the previous endeavors theauthor designs and making a experimental switch，accounting into many facets：the circuitlayout and structure、electromagnetic interference、IGBT cooling conditions and so on.In the phase of testing，we can use this switch to check and implement some of theIGBT’s parallel current-sharing、protection methods、driver debugging or other necessarythoughts in order to achieve optimal application of IGBT in pulsed power technology. Byanalyzing these consequences the author make some conclusions：Gate-resistor adjustingcan be used to improve current-sharing during switching phases、feedback control ofGate-Emitter voltage need large scale of voltage changing to have an effect、feedbackregulation of trigger’s edge only be effected in some special conditions.