§2 AC-DC Converte中學英語課件

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity§2AC/DCRectifierDr.Maoxingkui2023/7/31CollegeofElectrical&Automation

Engineering,FuzhouUniversity§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity單相半波可控a.純阻性負載b.純感性負載c.阻感負載§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity改進單相半波可控§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity單相橋式全控a.純阻性負載b.阻感性負載，且τ=L/R?TZ§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversityc.反電動勢+阻感性負載(τ=L/R?T)§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity單相全波可控整流電路單相橋式半控整流電路§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity主要內(nèi)容§2.2三相SCR可控硅Rectifier§2.3變壓器漏感對Rectifier的影響§2.4電容濾波不控Rectifier§2.5Rectifier的Harmonics和PF§2.6Rectifier的有源逆變狀態(tài)§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity一.三相半波§2.2三相SCR可控硅Rectifier應用：負載容量較大，輸出電壓紋波小

1.電路原理圖a.一次側三角形,二次側星形b.晶閘管共陰極接法

c.電壓最高的相導通，輸出脈動3次（脈波數(shù)），周期2π/3

§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity①.Z=R自然換相點:各相晶閘管能觸發(fā)導通的最早時刻,a=0,電角度為30。數(shù)量關系：§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity②.Z=R+jωL,且τ=L/R》T

a≤30o:與純阻性負載相同

a>30o：不同于純阻性負載導通角都相同：θ=2π/3§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity二.三相全橋1.電路原理圖a.一次側三角形b.晶閘管共陰極、共陽極接法

c.工作時序/導通相共陰極：電壓最高相；共陽極：電壓最低的相，即對線電壓進行整流，一個周期輸出脈動6次，即輸出電壓周期為2π/6§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity①.Z=R-300數(shù)量關系：§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversitya=00a=600a=900§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity②.Z=R+jωL,且τ=L/R》T

a≤60o:與純阻性負載相同

a>60o：不同于純阻性負載導通角都相同：θ=π/3Return§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity§2.3變壓器漏感對Rectifier的影響ReturniK§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity§2.4電容濾波不控Rectifier一.單相1.電路原理圖2．工作原理及波形圖Ud=1.2U2，當τ=RC≥（3-5）T/2；最小Ud=0.9U2θ由ω、R、C決定

§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity§2.5Rectifier的Harmonics和PF一．諧波與無功危害1．諧波(harmonics)

2.無功(reactivepower)

二．H與R分析基礎1．HarmonicsHRi=In/I1*100%，In，I1：RMS

THD=Ih/I1*100%，Ih：總諧波電流RMS§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity2．PowerFactorλ正弦電路

ActivepowerP=UIcosФλ=P/S=I1/IcosФ=νcosФApparentpowerS=UIReactivepowerQ=UIsinФ非正弦電路

ActivepowerP=UI1cosФ

ApparentpowerS=UI§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity三．阻感負載可控整流

1．單相橋式全控λ=νcosа=0.9cosа

2．三相橋式全控諧波：奇次諧波λ=νcosа=0.955cosа

諧波：6k±1(k為正整數(shù))四．電容濾波不控1．單相橋式全控：奇次諧波2．三相橋式全控：6k±1(k為正整數(shù))諧波五．整流輸出電壓、電流諧波：mk次（m:脈波數(shù)）

Return§2AC-DCConverte24-Jan-22DeltaEnergySystems§2.6大功率可控整流電路-帶平衡電抗器的雙反星形可控整流電路§2AC-DCConverte24-Jan-22DeltaEnergySystems0a)b)c)d)ia1Id180°360°ia2iab2'iAIdiab2wtwtwtwt000Id2333Id33IdId323(1+

)Id323(1+)Id33Id13§2.6大功率可控整流電路-多重化-移相控制§2AC-DCConverte24-Jan-22DeltaEnergySystems§2.6大功率可控整流電路-多重化-順序控制db)c)iId2IduOap+a§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity§2.7Rectifier的有源逆變狀態(tài)一.逆變1.逆變直流電轉換為交流電。有源逆變：交流側與電網(wǎng)連接；反之為無源逆變。2.逆變條件

①.α≥900，輸出電壓為負值；②.負載中要有反電動勢?！?AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity

直流發(fā)電機—電動機之間電能的流轉a）兩電動勢同極性EG

>EM

b）兩電動勢同極性EM>EG

c）兩電動勢反極性，形成短路§2AC-DCConverte24-Jan-22DeltaEnergySystems

2023/7/31Dr.MaoDepartmentofElectricalEng.&AutomationofFuzhouUniversity3.逆變角

逆變角β=π-α，α以自然換相點為起始點，向右計算；β以β=0,即α=π為起始點為起始點，向左計算。Return§2AC-DCConverte24-Jan-22DeltaEnergySystemsuabuacubcubaucaucbuabuacubcubaucaucbuabuacubcubaucaucbuabuacubcuaubucuaubucuaubucuaubu2udwtOwtOb=p4b=p3b=p6b=p4b=p3b=p6wt1wt3wt2§2AC-DCConverte24-Jan-22DeltaEnergySystems§2.8晶閘管直流電動機系統(tǒng)2.8.1工作于整流狀態(tài)