单端反激DC-DC-Matlab仿真

1、计算机仿真技术作业五题目：单端反激DC/DC电路仿真?利用simpowersystems建立单端反激电路的仿真模型。输入直流电压28V, 输出电压5V，输出额定功率30W。电路开关频率10kHz，整流二极管通 态压降0.7V，计算功率管的工作占空比，并选择开关管（选择 MOSFET） 及二极管。模型建立:建立单端反激变换器电路模型如下图:STr-irW9理论计算:计算功率管占空比：由叫=2N,28UoN1-Ud，得 D=50%1 D仿真过程:仿真算法选择ode23tb，最大步长设为 变压器仿真设置? 1满负载的仿真。DC/DC变换器，R=0.68欧姆，C=4700uf,仿真时间0.2s。观察并

2、记录MOSFET的工作波形（电压，电流波形），输出整流二极管的 工作波形（电压，电流波形），输出电压波形。MOSFET的工作波形（电压，电流波形）MOSFET yOltage5040v 3020100.08630.08640.08650.08660.08670.08680.08690.0870.08710.08720.0873Time/seaalro TETSOM060MOSFET cUrrent32.521.510.50-0.50.08630.08640.08650.08660.08670.08680.08690.0870.08710.08720.0873Time/s整流二极管的工作波形（电

3、压，电流波形）Diode voltage0.11750.11760.11780.11790.1180.11810.11820.11830.1184Time/s0.1177Diode curre ntTime/sOutput voltage4.180.060.06010.06020.06030.06040.06050.0606Time/s2432.221 22449 di52wreewwrro vr unruo0.06074.170.0599由上图可得输出电压稳态值为 Vo=4.212V,纹波电压为 Vo= 0.0655V选择占空比D=53%时，输出电压稳态值为 Vo=5.006VMOSFET的

4、工作波形（电压，电流波形）Diode voltagev/eaarro V edobTime/sDiode curre ntTime/s整流二极管的工作波形（电压，电流波形）Diode voltage0.05120.05130.05140.05150.05160.05170.0518Time/sv/eawwrrov eai0.0519Diode curre nteaniTime/s5.055.04II5.035.025.014.994.984.97i.lI:4.964.95 1L0.06830.06840.0685Output voltageI)II11|iiIlj1IiI;0.06860.06

5、870.0688Time/s0.06890.0690.06910.06920.0693输出电压稳态值为 Vo=5.006V，纹波电压为 Vo= 0.0828 V? 2.小负载的仿真。R=10欧姆，C=4700uf仿真时间0.5&选择合适占空比 使得输出电压为5V。观察并记录MOSFET的工作波形（电压，电流波 形），输出整流二极管的工作波形（电压，电流波形），输出电压波形。当占空比为D=35.85%时，输出电压Vo=5.001VMOSFET的工作波形（电压，电流波形）MOSFET voltage0.0750.07520.07540.07560.0758Time/s0.0760.07620.07

6、640.0766v/eaflrrov T-bFS OM0.0750.07520.07540.07560.0758Time/s0.0760.07620.07640.0766MOSFET curre nt整流二极管的工作波形（电压，电流波形）weaHrLUV ean&20-2-4-6-8Diode voltage0.05140.05150.05160.05180.05190.0520.05130.0517Time/s0.0521-10.05130.05140.05150.05160.05180.05190.0520.0521Diode curre nt432100.0517Time/s5.0065

7、.0055.004I5.003输出电压波形Output voltage11.(lH.Iwv/6aalroylunru o5.0025.0014.999i4.9984.9974.996 0.17960.17980.18i|il0.1802Time/s0.18040.18060.1808由上图可得输出电压稳态值为 Vo=5.001V,纹波电压为 Vo= 0.0076V?通过仿真分析，选择合适的功率管和整流二极管(耐压，耐流)。二极管的选取要根据原边的(交流电压峰值/匝比+输出电压)+百分之二十的最高电 压+百分之十到二十的余量=二极管最终选取电压值由满负载仿真情况，功率管耐压值为100V，耐流值为

8、8A二极管耐压值为20V，耐流值为30A附录：Script:Flyback.msubplot(2,1,1)plot(MOSFET.MOSFET_voltage)axis(0.075,0.0766,-10,70)xlabel(Time/s) ylabel(MOSFET voltage/V) title(MOSFET voltage) subplot(2,1,2) plot(MOSFET.MOSFET_current) axis(0.075,0.0766,-0.5,1) xlabel(Time/s) ylabel(MOSFET current/A) title(MOSFET current) figure(2) subplot(2,1,1) plot(Diode.Diode_voltage) axis(0.0513,0.0521,-12,2) xlabel(Time/s) ylabel(Diode voltage/V) title( Diode voltage) subplot(2,1,2) plot(Diode.Diode_current) axis(0.0513,0.0521,-1,4) xlabel(Time/s) ylabel(Diode cur