开关电源拓朴结构分析

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开关电源拓朴结构分析FAENAME:CARY.CHENSZ22电源的分类什么是PowerSupply?PowerSupply负载Vin,IinPowerSupply是一种提供电力能源的设备,它可以将一种电力能源形式转换成另外一种电力能源形式,并能对其进行控制和调节。上级电能形式Vo,Iof,phasef,phase根据转换的形式分类:AC/DC,DC/DC,DC/AC,AC/AC根据转换的方法分类:线性电源,相控电源,开关电源根据调控的效果分类:稳压,恒流,调频,调相根据调控的方法分类:传统反馈控制,矢量控制,数位控制3开关电源的元件构成开关电源的基本元件:有源开关(Switch)二极管(Diode)电感(Inductor)电容器(Capacitor)变压器(Transformer)4三种基本的非隔离开关电源VinVoLIoSDVinVoDLIoS1DS2VinVoDLIoSVo=Vin*D/(1-D)Vo=Vin*DVo=Vin/(1-D)VoVin,降压型电路VoVin,升压型电路VoVin,当D0.5VoVin当D0.5升降压型电路5三种基本的隔离开关电源VinVoSLmDVinVoLSD1D2VinVoLS1D1D2S2正激型变换器反激型变换器桥式变换器6反激变换器(Flyback)工作原理(电流连续模式)根据变压器的伏秒平衡:TDnVoDTVin)1(**)1(**DnDVinVoIoVinVoGDSLmDn:1ConVoVinVds)1(DVinVdsVgsIDVdsD1-DTIpIoVinVin+nVoImVLVin-nVoID-p7反激变换器(Flyback)工作原理(电流断续模式)根据变压器的伏秒平衡:)1(**DnDVinVoIoVinVoGDSLmDn:1CoVgsIDVdsD1-DTIoVinVin+nVoImVLVin-nVo’ID-p-nVoVoVo'TRVoLmIp2221根据能量守恒:LmVinDTIpVinDLmRTVo28反激变换器(Flyback)工作原理(1)221221LkIpCdsVrnIIppDVgsIDVdsD1-DTIpIoVinVin+nVoImVrVLVin-nVoID-p21DopDIDIIVr=?IoVinVoGDSLmDn:1LkCoLmTDVoID/)1(IpCdsLkVr*9反激变换器(Flyback)工作原理(2)VcIoVinVoGDSLmDn:1LkCoVcRPloss=(Vc-Vin)2/RGDSLkVcRPloss=(Vc)2/R10反激变换器(Flyback)工作原理(3)ΔVo=?IoVinVoGDSLmDn:1LkCo)1/(DIIIopDCoVgsIDVdsD1-DTIpIoVinVin+nVoImVrICoID-p-IoVoDTIVCOOCDTIVOO/根据Co在DT时间的基本方程:11反激变换器(Flyback)工作原理(4)多路输出的反激变换器:)1(***11DNpDVinNsVo)1(***22DNpDVinNsVo减小交叉调整率的措施:1.尽量减少两个绕组之间的漏感。2.在辅助输出一路中加入尖峰抑制器(饱和电感)3.主路输出工作于电流连续模式。4.采用双路加权反馈的控制方式VinVo1GLmNpLkVo2Ns2Ns1反馈控制12反激变换器(Flyback)特征总结缺点:1.输出纹波电流大。2.输出控制特性非线性。3.通常需要辅助的吸收回路。4.转换效率较低。VinVo1GLmNpLkVo2Ns2Ns1反馈控制优点:1.电路简单。2.输入电压范围广。3.容易实现多路输出。13谐振复位正激变换器(ResonantResetForward)(1)Ion:1VinVoLoGDSVgsILVdsD1-DTIpVLIoVin/n-Vo-VoImVinΔILILLmLkCrt0t1t2t3t4Ip[t0,t1]t5LmVinDTIm/LoDTVonVinIL/)/(LmPInII14谐振复位正激变换器(ResonantResetForward)(2)Ion:1VinVoLGDSVgsILVdsD1-DTIpVLIoVin/n-Vo-VoImVinΔILILLmLkCrt0t1t2t3t4Ip[t1,t2]t5LmLkIIVVmpc211VcV15谐振复位正激变换器(ResonantResetForward)(3)Ion:1VinVoLGDSVgsILVdsD1-DTIpVLIoVin/n-Vo-VoImVinΔILILLmLkCrt0t1t2t3t4Ip[t2,t3]t51VcVcVrminCLDTV216谐振复位正激变换器(ResonantResetForward)(4)Ion:1VinVoLGDSVgsILVdsD1-DTIpVLIoVin/n-Vo-VoImVinΔILILLmLkCrt0t1t2t3t4Ip[t3,t4]t5LmCrtt14Lm,Cr的选取原则:22max2)1(1*TDCrLm17谐振复位正激变换器(ResonantResetForward)(5)Ion:1VinVoLGDSVgsILVdsD1-DTIpVLIoVin/n-Vo-VoImVinΔILILLmLkCrt0t1t2t3t4Ip[t4,t5]t5(Vin/n-Vo)DT=Vo(1-D)T根据电感的伏秒平衡:Vo=VinD/n18谐振复位正激变换器(ResonantResetForward)特征VinVoCr缺点:1.原边开管电压应力较高。2.谐振电容的损耗大。3.宽范围输入效率很难兼顾。优点:1.电路简单。2.线性输出控制特性。3.不需要辅助的吸收回路。VinVoCrVinVoCr19有源钳位正激变换器(ActiveClampedForward)(1)Ion:1VinVoLoGDSSaILVdsDTIpVTIoVin/n-Vc/nImVinΔILILLmLkCrt0t1t2t3t4Ip[t0,t1]t5LmVinDTIm/LoDTVonVinIL/)/(LmPInIIS1S1Sa1-D+VT-20有源钳位正激变换器(ActiveClampedForward)(2)Ion:1VinVoLoGDSSaILVdsDIpVTIoVin/n-Vc/nImVinΔILILLmLk-Vc+t0t1t2t3t4Ip[t1,t2]t5LkIpttVcIm)()12(S1S1Sa1-D+VT-VcLknIott/*)/()12(1td2td*副边电压的死区跟Lk和Io有关,跟原边开管的死区无关21有源钳位正激变换器(ActiveClampedForward)(3)Ion:1VinVoLoGDSSaILVdsDIpVTIoVin/n-Vc/nImVinΔILILLmLk-Vc+t0t1t2t3t4Ip[t2,t3]t5S1S1Sa1-D+VT-)12(1tttd1td2tdSa在零电压条件下开通*原边开管的死区时间需满足:22有源钳位正激变换器(ActiveClampedForward)(4)Ion:1VinVoLoGDSSaILVdsDIpVTIoVin/n-Vc/nImVinΔILILLmLk-Vc+t0t1t2t3t4Ip[t3,t4]t5S1S1Sa1-D+VT-1td2td激磁电流反向,变压器被复位LmTDVcIm/)1(23有源钳位正激变换器(ActiveClampedForward)(5)Ion:1VinVoLoGDSSaILVdsDIpVTIoVin/n-Vc/nImVinΔILILLmLk-Vc+t0t1t2t3t4Ip[t4,t5]t5S1S1Sa1-D+VT-1td2td激磁电流对主开关的输出电容放电。t6=t024有源钳位正激变换器(ActiveClampedForward)(6)Ion:1VinVoLoGDSSaILVdsDIpVTIoVin/n-Vc/nImVinΔILILLmLk-Vc+t0t1t2t3t4Ip[t4,t5]t5S1S1Sa1-D+VT-1td2td激磁电流对主开关的输出电容放电。t6=t025有源钳位正激变换器(ActiveClampedForward)(7)Ion:1VinVoLoGDSSaILVdsDIpVTIoVin/n-Vc/nImVinΔILILLmLk-Vc+t0t1t2t3t4Ip[t5,t6]t5S1S1Sa1-D+VT-1td2tdt5时刻副边二极管钳位主开关的输出电容放电结束。t6时刻新的周期开始t6=t026有源钳位正激变换器(ActiveClampedForward)(8)Ion:1VinVoLoGDSSaILVdsDIpVTIoVin/n-Vc/nImVinΔILILLmLk-Vc+t0t1t2t3t4Ipt5S1S1Sa1-D+VT-1td2tdt6=t0(Vin/n-Vo)DT=Vo(1-D)T根据电感的伏秒平衡:Vo=VinD/nVinDT=Vc(1-D)T根据变压器的伏秒平衡:Vc=VinD/(1-D)Vds=Vc+VinVds=Vin/(1-D)27有源钳位正激变换器(ActiveClampedForward)(9)00.10.20.30.40.50.60.70.80.91012345678910VcD()VdsD()DVc=VinD/(1-D)Vds=Vin/(1-D)Vin28有源钳位正激变换器(ActiveClampedForward)(10)VinVoVinVoVinVoSaSaSa缺点:1.钳位电压建立较慢,启动过程变压器易偏磁。2.对输入电压的动态响应慢。优点:1.变压器最优化复位(电压应力低)。2.输入电压范围宽。3.线性输出控制特性。4.不需要辅助的吸收回路。29桥式变换器(BridgeTypeConverter)VinVoLS1D1D2S2半桥变换器VinVoLS1D1D2S2全桥变换器VinVoLS1D1D2S2推挽变换器VinVoS1D2S2半桥变换器(倍流整流)30桥式变换器(BridgeTypeConverter)(1)VinVoLoS1D1D2S2n:1+1LmLkIpIoCBVTS1ILVds1DIpVTIoVin/2n-Vin/2nImVinΔILt0t1t2t3t4t5S2Dt6=t0T/2T/2Vc[t0,t1]变换器正半周工作,Ip,Im增加;Vc减少。LmDTVinIm/2)12/()/(CDTnIoVcC1C131桥式变换器(BridgeTypeConverter)(2)VinVoLoS1D1D2S2n:1+1LmLkIpIoBVTS1ILVds1DIpVTIoVin/2n-Vin/2nImVinΔILt0t1t2t3t4t5S2Dt6=t0T/2T/2VcC1CC1Vin/2[t1,t2]S1关断,变压器副边续流,原边漏感能量被S2体二极管钳位。32桥式变换器(BridgeTypeConverter)(3)VinVoLoS1D1D2S2n:1+1LmLkIpIoBVTS1ILVds1DIpVTIoVin/2n-Vin/2nImVinΔILt0t1t2t3t4t5S2Dt6=t0T/2T/2VcC1CC1Vin/2[t2,t3]S1,S2全部关断,变压器副边续流,Lm保持不变,D1,D2电流之差为Lm。33桥式变换器(BridgeTypeConverter)(4)VinVoLoS1D1D2S2n:1+1LmLkIpIoABS1ILVds1DIpVTIoVin/2n-Vin/2nImVinΔILt0t1t2t3t4t5S2Dt6=t0T/2T/2Vin/2VTVc[t3,t4]变换器负半周工作,Ip,Im减少;Vc增加。LmDTVinIm/2)12/()/(CDTnIoVc34桥式变换器(BridgeTypeConverter)(5)VinV

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