Research On Basic Technology Of GaN Device Application

As one of the cores of power electronic converters,the power semiconductor device will improve the performance of the converter every time it is updated.The third-generation wide bandgap semiconductor device is represented by GaN.Compared with Si devices,it is more suitable for working in high-frequency,high-temperature,and high-efficiency environments.It can greatly reduce the size of magnetic components in the converter and increase power density.However,GaN devices have high switching speeds,are sensitive to parasitic parameters,and are susceptible to damage due to oscillation and overshoot during application.Therefore,the research and analysis of GaN devices and their application methods are the urgent problems to be solved to give full play to the performance of GaN devices,and have great significance.This article mainly studies the application methods of high-voltage GaN devices.Firstly,analyzes the driving circuit containing parasitic parameters on the double-pulse test circuit,and obtains the LCR differential equation of the driving circuit and the corresponding transfer function,and gives the best driving state-each of the driving circuit under slightly underdamped response The relationship between indicators and RLC.In this paper,the method of calculating PCB wiring inductance is given,the simulation of the effect of driving parasitics on V_GSis carried out,a suitable driving circuit is designed,the method of circuit layout optimization is given,and the effectiveness of this method is verified by experimental comparison.In the actual engineering state,it is difficult to test the switching characteristics of GaN devices.This article compares the test results of voltage test equipment with different bandwidths and common current test methods,summarizes the basic equipment requirements and measurement methods for GaN device testing,and gives them through experimental comparison.A suitable method for selecting test points is presented.The effect of parasitic inductance and capacitance on the performance of GaN switch is analyzed by simulation in a double-pulse test circuit with parasitic parameters.The parasitic parameters in the actual circuit were extracted by Ansys Q3D Extractor software,and the simulation circuit containing parasitic parameters was built in LTspice.The simulation results were basically consistent with the experimental waveform.On this basis,combined with the calculation method of PCB routing inductance,the main points for attention of GaN device circuit layout are summarized,which provides a reference basis for the prediction,optimization and layout of the actual converter design.Finally,GaN device is applied to Boost PFC power supply,main circuit and control circuit are analyzed and designed,and PFC experimental prototype is built.The prototype realized PFC function and the efficiency of the whole machine reached97.5%.The loss composition of the prototype is calculated,the heat distribution of the prototype is analyzed,and the temperature is measured.In the actual debugging process,the problem of voltage oscillation on GaN devices in the circuit is solved,and the effectiveness of the testing method and layout optimization is verified.