计算机仿真技术作业二题目:带电容滤波的三相不控整流桥仿真利用simpowersystems建立三相不控整流桥的仿真模型。输入三相电压源,线电压380V,50Hz,内阻0.001Ω。三相二极管整流桥可用“UniversalBridge”模块,二极管采用默认参数。直流滤波电容3300μF,负载为电阻。仿真时间0.3s。注:前三项只考虑稳态情况,第四项注重启动过程。建立系统仿真模型如下图:仿真算法选择ode23tb,最大步长为1μs,仿真时间0.3s理论计算:当二极管用理想开关代替,直流侧空载时,输出直流电压与输入交流线电压的关系如下:0321.35513VdLLLLVVV交流侧电流有效值:20.8163sddIII交流侧基波电流有效值:160.78sddIII1、直流电压与负载电阻的关系:分别仿真整流电路空载及负载电阻为10、1和0.1欧姆时的情况。记录直流电压波形,根据仿真结果求出直流电压,并比较分析其与负载的关系。理论计算(1)空载时直流电压Ud=537.4V,纹波电压ΔUd=00.060.0620.0640.0660.0680.070.0720.0740.0760.0780.08536536.2536.4536.6536.8537537.2537.4537.6537.8538Time/sUd/VUd(noload)(2)负载电阻为50Ω时直流电压Ud=533.2V,纹波电压ΔUd=8.75V0.020.030.040.050.060.070.08525530535540Time/sUd/VUd(R=50ohm)(3)负载电阻为10Ω时直流电压Ud=523.3V,纹波电压ΔUd=32.5000V0.060.0650.070.0750.080.0850.090.0950.10.105500505510515520525530535540Time/sUdUd(R=10ohm)(4)负载电阻为1Ω时直流电压Ud=511.1V纹波电压ΔUd=70.9100V0.030.040.050.060.070.080.09460470480490500510520530540Time/sUdUd(R=1ohm)(5)负载电阻为0.1Ω时直流电压Ud=493.5V纹波电压ΔUd=64.9500V0.040.0450.050.0550.060.0650.070.075450460470480490500510520Time/sUdUd(R=0.1ohm)结论:由以上仿真结果可得到如下结论:输出直流电压的值随着负载电阻的减小而减小2、电流波形与负载的关系:分别仿真负载电阻为10、1.67和0.5时的情况。记录直流电流和a相交流电流,并分析规律。(1)负载电阻为50Ω时,a相交流电流和直流电流波形如下图:0.050.10.15-150-100-50050100150Time/sIa/AIa(R=50ohm)0.050.10.1510.5510.610.6510.710.7510.8Time/sId/AId(R=50ohm)(1)负载电阻为10Ω时,a相交流电流和直流电流波形如下图:0.010.020.030.040.050.060.070.080.09-200-1000100200Time/sIa/AIa(R=10ohm)0.010.020.030.040.050.060.070.080.09505152535455Time/sId/AId(R=10ohm)(2)负载电阻为1.67Ω时,a相交流电流和直流电流波形如下图0.020.040.060.080.10.120.140.160.180.2-600-400-2000200400600Time/sIa/AIa(R=1.67ohm)0.020.040.060.080.10.120.140.160.180.2270280290300310320330Time/sId/AId(R=1.67ohm)(3)负载电阻为0.5Ω时,a相交流电流和直流电流波形如下图0.10.110.120.130.140.150.160.170.180.190.2-1500-1000-500050010001500Time/sIa/AIa(R=0.5ohm)0.10.110.120.130.140.150.160.170.180.190.2900950100010501100Time/sId/AId(R=0.5ohm)结论:由以上仿真结果可得到以下结论,随着负载电阻的减小,直流侧电流Id,交流侧电流Ia逐渐增大,直流侧电流有效值和交流侧电流有效值具有如下的近似关系:0.9231adII当负载电阻为1.67Ω时,输出电压为Vd=512v,与理论计算接近。0200400600800100012000100200300400500600700800900Id/AIa/AIa-IdCurve(Ls=0)Ia-Id曲线3、平波电抗器的作用直流侧加1mH电感。分别仿真轻载50欧姆和重载0.5欧姆时的情况,记录直流和交流电流波形,并计算交流电流的THD。仿真同样负载条件下,未加平波电抗器的情况,并加以比较分析。计算交流电流的THD负载电阻R(Ω)加平波电抗器L=1mH时的THD不加平波电抗器时的THD502.398%2.398%0.50.3426%0.3437%(1)加入平波电抗器L=1mH,负载电阻为50Ω时0.020.030.040.050.060.07-150-100-50050100150Time/sIa/AIa(L=1mHR=50ohm)0.020.030.040.050.060.0710.410.4510.510.5510.610.6510.710.7510.8Time/sId/AId(L=1mHR=50ohm)不加平波电抗器,负载电阻为50Ω时0.050.10.15-150-100-50050100150Time/sIa/AIa(R=50ohm)0.050.10.1510.5510.610.6510.710.7510.8Time/sId/AId(R=50ohm)(2)加入平波电抗器L=...