Design Of IGCT Switching Circuit For Gate Hard Driver

Integrated Gate Commutated Thyristor(IGCT)is a new high power semicondoctor device based on the development of Gate Turn-off Thyristor(GTO).It has advantages,such as,high voltage,low conductance voltage drop,high switching speed,hard drive and bufferless turn-off,etc.thus has a very good application prospect in the high-voltage power electronic equipments.The switching of IGCT must be realized by the integrated gate hard driver circuit,which can directly affect the performance of the device.Therefore,the design of the gate hard driver circuit is an indispensable part in the research of IGCT technology.This paper take the 1100A/4500V IGCT as the research objects.Based on the analysis of operation principle and requirement of driver circuit parameters,an GCT equivalent circuit mode which is suitable for circuit simulation is established,and the switching circuit for gate hard drive is designed.The main contents are as follows:Firstly,a 2T-3R-C model suitable for IGCT circuit simulation is established,and the key model parameters are determined,which are the double transistor current amplification factor,the 3 characteristic resistance and the J2 junction barrier capacitance.Based on the IGCT dynamic characteristic test circuit provided by ABB,the switching characteristics of the model of GCT is simulated,the simulation waveforms are in good agreement with the measured waveform.Secondly,the operation priciple of GCT driver circuit and design requirement are described briefly,the sitching circuit for IGCT hard driver is designed.Based on the established GCT equivalent circuit model,the turn-on,turn-off and the maintenance circuits,and the driving circuit of the MOSFET switch are simulated and validated by the PSPICE software.And then the DC power supply,the state detection and display circuit and the optical software.And then the DC power supply,the state detection and display circuit and the optical fiber transceiver circuit used in the circuit are also designed.Finally,the experimental circuit is set up to test the turn-on circuit.The waveform shape of the gate current IG measured by the experiment is in accordance with the requirements of the turn-on circuit,but the current amplitude is too small,the reason is analyzed and the further provement measures are put forward.The reserach result has a reference value for the devolpment of the IGCT gate hard drive circuit.