5.4电压型逆变电路 Voltage type inverter circuit中英版

Voltagetypeinvertercircuit5.4电压型逆变电路TeachingResourcesDatabaseof

NationalVocationalEducationPowerSupplyTechnologyBilingualcourses.Powerelectronicstechnology电力电子技术Item5InverterCircuit项目五逆变电路1、电压型逆变电路半桥逆变电路工作原理Theworkingprincipleofvoltage-typeinverterhalf-bridgeinvertercircuitVoltagetypeinvertercircuit5.4电压型逆变电路图2

电压型半桥逆变电路及其电压电流波形Fig.2Voltage-typehalf-bridgeinvertercircuitanditsvoltagecurrentwaveform

在一个周期内，电力晶体管T1和T2的基极信号各有半周正偏，半周反偏，且互补。Inonecycle,thebasesignalsofthepowertransistorsT1andT2havesemi-cyclepositivebiasandsemi-cyclenegativebiasrespectively,andarecomplementary.若负载为阻感负载，设t2时刻以前，T1有驱动信号导通，T2截止，则u0=Ud/2。Iftheloadisresistiveload,itisassumedthatbeforethetimeT2,thedrivesignalinT1isonandT2isoff,thenu0=Ud/2.

t2时刻关断的T1，同时给T2发出导通信号。由于感性负载中的电流i。不能立即改变方向，于是D2导通续流，u0=－Ud/2

。T1shutsoffattimeT2,andsendsaconductionsignaltoT2.Becausethecurrenti。intheinductiveloadcannotchangedirectionimmediately,soD2conductioncontinuesthecurrent,u0=Ud/2.t3时刻i。降至零，D2截止，T2导通，i。开始反向增大，此时仍然有u0=－Ud/2

。AtT3,i。dropstozero,D2stops,T2turnson,andi。startstoincreaseintheoppositedirection,sothereisstillu0=Ud/2.在t4时刻关断T2，同时给T1发出导通信号，由于感性负载中的电流i。不能立即改变方向，D1先导通续流，此时仍然有u0=Ud/2；AtthetimeofT4,T2isshutoffandaconductionsignalissenttoT1.Sincethecurrenti。intheinductiveloadcannotchangedirectionimmediately,D1leadstothecontinuationofthecurrent.Atthistime,thereisstillu0=Ud/2.t5时刻

i。降至零，T1导通，u0=Ud/2；AtthetimeT5,i。dropstozero,T1conduction,u0=Ud/2;电压型单相半桥逆变电路的特点

Characteristicsofvoltage-typesingle-phasehalf-bridgeinvertercircuit缺点：Disadvantages:1）交流电压幅值仅为Ud/2；ACvoltageamplitudeisonlyUd/2;2）直流侧需分压电容器；DCsideneedsvoltagedividercapacitor;3）为了使负载电压接近正弦波通常在输出端要接LC滤波器，输出滤波器LC滤除逆变器输出电压中的高次谐波。Inordertomaketheloadvoltageclosetothesinewave,LCfilterisusuallyconnectedattheoutputend,andtheoutputfilterLCfiltersoutthehigh-orderharmonicsintheoutputvoltageoftheinverter.优点：简单，使用器件少；Advantages:simple,uselessdevices;应用：用于几kW以下的小功率逆变电源；Application:forafewkWbelowthelow-powerinverterpowersupply;Voltagetypeinvertercircuit5.4电压型逆变电路1、电压型单相全桥逆变电路电路工作过程：Voltagetypesingle-phasefull-bridgeinvertercircuitworkingprocess:Voltagetypeinvertercircuit5.4电压型逆变电路全控型开关器件T1和T4构成一对桥臂，T2和T3构成一对桥臂,T1和T4同时通、断；T2和T3同时通、断。T1(T)4与T2(T3)的驱动信号互补，即T1和T4有驱动信号时，T2和T3无驱动信号，反之亦然，两对桥臂各交替导通180°。Full-controlswitchdeviceT1andT4constituteapairofbridgearms,T2andT3constituteapairofbridgearms,T1andT4areonandoffatthesametime;

T2andT3areonandoffsimultaneously.

ThedrivingsignalsofT1(T)4andT2(T3)arecomplementary,thatis,whenT1andT4havedrivingsignals,T2andT3havenodrivingsignals,andviceversa,andthetwopairsofbridgearmseachconductalternatelyat180°.图2

电压型半桥逆变电路及其电压电流波形Fig.2Voltage-typehalf-bridgeinvertercircuitanditsvoltagecurrentwaveform

输出方波电压瞬时值：Outputsquarewavevoltageinstantaneousvalue:

输出方波电压有效值：Effectivevalueofoutputsquarewavevoltage:基波分量的有效值：Effectivevalueoffundamentalwavecomponent:同单相半桥逆变电路相比，在相同负载的情况下，其输出电压和输出电流的幅值为单相半桥逆变电路的两倍。Comparedwithsingle-phasehalf-bridgeinverter,underthesameload,theamplitudeofoutputvoltageandoutputcurrentistwicethatofsingle-phasehalf-bridgeinverter.1）纯电阻负载时

WhenpureresistanceloadVoltagetypeinvertercircuit5.4电压型逆变电路图2

电压型半桥逆变电路及其电压电流波形Fig.2Voltage-typehalf-bridgeinvertercircuitanditsvoltagecurrentwaveform

2）电感负载时

Whentheinductorisloaded由可得负载电流峰值为：Voltagetypeinvertercircuit5.4电压型逆变电路图2

电压型半桥逆变电路及其电压电流波形Fig.2Voltage-typehalf-bridgeinvertercircuitanditsvoltagecurrentwaveform

0≤t＜Ts／4，Ts2≤t≤3Ts／4期间，D1、D4导通起负载电流续流作用，在此期间T1∼T4均不导通。Duringtheperiodof0≤t<TS/4andTS2≤T≤3TS/4,D1andD4conductionplaystheroleofloadcurrentcontinuation.Duringthisperiod,T1-T4isnotconduction.Accordingtothepeakvalueofloadcurrentcanbe:3）阻感负载RL时

WhentheresistiveloadisRL图2(e)所示是RL负载时直流电源输入电流的波形。Figure2(e)showsthewaveformoftheDCinputcurrentatRLload.Voltagetypeinvertercircuit5.4电压型逆变电路图2

电压型半桥逆变电路及其电压电流波形Fig.2Voltage-typehalf-bridgeinvertercircuitanditsvoltagecurrentwaveform

0≤θ≤ωt期间，T1和T4有驱动信号，由于电流i0为负值，T1和T4不导通，D1、D4导通起负载电流续流作用，u0=+Ud。During0≤θ≤ωt,T1andT4havedrivingsignals,becausethecurrentI0isnegative,T1andT4donotconduct,D1andD4conductionplaytheroleofloadcurrentcontinuation,u0=+Ud.θ≤ωt≤π期间，i0为正值，T1和T4才导通。Duringθ≤ωt≤π,whenI0ispositive,T1andT4conduct.π≤ωt≤π+θ期间，T2和T3有驱动信号，由于电流i0为负值，T2、T3不导通，D2、D3导通起负载电流续流作用，u0=－Ud。Duringπ≤ωt≤π+θ,T2andT3havedrivingsignals,becausethecurrentI0isnegative,T2andT3donotconduct,D2andD3conductionplaysaroleofloadcurrentcontinuation,u0=－Ud

.π+θ≤ωt≤2π期间，T2和T3才导通。T2andT3conductduringπ+θ≤ωt≤2π.Thanksforwatching