1、AC controllersFrequency converters(Cycloconverters)AC to AC convertersPowerElectronics1PowerElectronics3PowerElectronicsRu1uoioVT1VT2Ou1uoiouVTwtOwtOwtOwt6ww2sin21dsin21121oUttUURUIoo)22sin1(21sin221121wwRUtdRtUIT2sin211oo1ooUUIUIUSPRu1uoioVT1VT20.6Ou1uoiouVTwtOwtOwtwtOuG1uG2OOwtwt0sin2ddo1oowwtitUR
2、itiL0201006014018020100图4-360/()180140/()=9075604530150tg)sin()sin(e12sin()sin()ttgoUiteZt wwwwtwtwtwt图4-5OOOOu1iG1iG2ioiT1iT2PowerElectronics060120180Fundamental357/()In/I*/%2040608010011nn abcUa0VT5VT3VT6VT4VT2VT1 4 32 35 3 302 uaouauab2uac2t1t2t3VT1VT3VT6VT4VT6VT2VT5VT5VT14 32 35 3302 uaouauab2ua
3、c2t1t2t3VT5VT1VT3VT4VT6VT2VT6VT5432353302uaouauab2uac2VT5VT1VT3VT4VT6VT2VT6VT5VT5VT1VT3VT5VT4VT2VT4VT6MControl period=M*Line period=24MO=2NM3M2Muou1uo,iowtU12Ru1uoioVT1VT2Harmonic order as to control frequencyHarmonic order as to line frequency051234012 142 4 61080.60.50.40.30.20.1In/I0mououououZPNu
4、oOuoP=0P=2P=2wtOutput voltageAverage output voltagetttttOOOOOuo,iouoiot1t2t3t4t5uouPuNuoiPiNuPuNuoioiNiP1OO23456图4-20uoiowtwtPrinciple of cosine wave-crossing method图4-21u2u3u4u5u6u1us2us3us4us5us6us1uoP3P4wtwtcosd0oUu tUuoomosinwttUUood0omsinsincosww)sin(coso1tw)10(d0omrUU=0=0.1/()Output voltage ph
5、ase anglew 0 t12015018030609000.10.20.30.80.91.00.80.20.30.91.022230.8 0.6 0.4 0.2 0=1.001.00.80.60.40.200.80.60.40.20.80.60.40.2200t/ms200t/ms200t/ms000a)b)abcuvwS11S12S13S21S22S23S31S32S33Sija)b)c)UmU1mU1m23Um12Single-phase input voltageUse 3 phase voltages to construct output voltageUse 3 line-line voltages to construct output voltage
