Design Of Logic Circuit For Dual-GCT Driver

Dual-GCT is a new type of high-power semiconductor device based on Integrated Gate Commutated Thyristors(IGCT).It combines two GCT devices with different characteristics into one single wafer,further reducing the total loss of the device,promising in medium and high voltage applications.Since there is a delay between the two GCTs' turn-off signals when the Dual-GCT is turned off,it is necessary to design a more reasonable logic circuit for the driver of the Dual-GCT,which ensures stable operation of the Dual-GCT and its drive system.This paper studies and designs the logic circuit of the Dual-GCT.The main work is as follows:Firstly,according to the structural characteristics of the Dual-GCT and the timing requirements of the gate drive signal,the composition and function of the logic circuit are analyzed,at the same time,the logic circuit is divided into logic control module and state detection module.Combined with the turn-on,on-state and turn-off circuits of the Dual-GCT driver circuit,the principle of the logic circuit is analyzed in detail.Taking the NPC three-level circuit as an example,the condition of the Dual-GCT that needs to be retriggered is analyzed,and the voltage threshold of the device in different states is determined,which is used as the judgment basis of the detection system.Secondly,the design and simulation of the logic control module.Through analysising the principle and requirements of the logic control module,the control flow and implementation method of the logic control module are determined.Taking into account the characteristics of FPGA high-speed,parallel execution,FPGA is used as the control chip,and the logic control module is designed by Hardware Description Language Verilog HDL.Pre-simulation of the designed logic control module by ISE Design Suite software.Thirdly,the design and verification of the status detection module.According to the functional requirements of the detection module,the design scheme of the detection module is determined,and the voltage detection value of the device is compared with the threshold value,the logic control module is used as a basis for judging the state of the device.The designed status detection module was simulated using Cadence software.Then the parameters of the op amp chip and components were selected,and the PCB board was drawn with Altiun Designer software.The module was verified by experiments.Lastly,the vernfication of the logic circuit.The logic control module is combined with the status detection module to vernfy the different states of the device by specifying the voltage input signal of the detection module,and verifying the logic circuit.The result shows that the logic circuit meets the design requirements.