Page - 244 - in Emerging Technologies for Electric and Hybrid Vehicles
Image of the Page - 244 -
Text of the Page - 244 -
Energies 2017,10, 616
controlledbybothsides’ inverterbridgesofeachwinding, isaspecificonethatonlyOW-PMSMhas.
It is independentbecauseeverywindingdirectlyconnectswith twosides’ inverterbridgesandthere
isnodirectconnectionbetweenwindings. Independentmoderequiresbothsides’powersources to
supplyvoltageandcanaccomplishenergyflowbetweenpowersources throughwindings.
Figure1.StructureofOW-PMSMdrivesystem.
2.1.WindingModeFeaturesAnalysis
First,wewilldiscusspowersource limitationsonwindingmodes. Indifferentwindingmodes,
themaximumamplitudeof eachwinding’sphasevoltage isdifferent and theconnectionbetween
eachphase isdifferent too,which leads to adifference inbasic voltagevectors’ amplitude. When
thewindingmodeisstaror independent,acertainphasevoltagecannotbedeterminedaccordingto
the corresponding inverter bridge’s switching status andwill be influenced by inverter bridges’
switching status of other phases due to the load neutral point in star mode and themid-point
potentialdifference in independentmodefloating. For instance, instarmode,wheninverterswitch
statusesare (110) (phaseAandBupperbridgearmon,phaseClowerbridgearmon),phasevoltage
relations:uA=uB=Vdc/3,uC=−2Vdc/3;whenswitchstatusesare (100),phasevoltagerelations:
uA = 2Vdc/3, uB=uC=−Vdc/3. It can be seen that, althoughphaseA’s corresponding inverter
bridge’sswitchstatusesare thesameinbothsituations,owingto the loadneutralpoint’sfluctuation
in starmode, phase voltages uA in both situations are different. Using the schematic diagramof
mid-pointvoltage inFigure2,wecananalyzevoltagevectors.Wefirstequallydividepowersource
1andpowersource2 into twopartsaccording tovoltage todeterminevirtualmid-pointsmandn.
Thevoltagedifferencebetweeneach inverterbridge’soutputandthecorrespondingmid-point is the
mid-pointvoltageandisunaffectedbyfloatingneutralpotentialormid-pointvoltagedifference. Each
inverterbridge’s switchingstatusandmid-pointvoltagehasaone-to-onecorrespondence. Theresults
are identicalwhenusingmid-pointvoltageandphasevoltage forvoltagevectorsynthesis.
Starandtrianglemodesarepoweredviaasinglepowersourceandthemotor’s three-phasestator
windingsareconnected inaspecific topologystructure. Switchingstatusesof three-phase inverter
bridgescanformavoltagevector in themotorspaceplane.GiventhatDCbusvoltage isVdc,when
switching statuses are (110), synthesizingvoltage vector in star and trianglemodes are shown in
Figure 3a,b. Independentmode ispoweredbydual sources. Supposed that thevoltageofpower
source1 isVdc1 andthevoltageofpowersource2 isVdc2,whenleft switchstatusesare (110)andright
switchstatusesare (001),voltagevectorsynthesis in independentmodeisshowninFigure3c.
244
Emerging Technologies for Electric and Hybrid Vehicles
- Title
- Emerging Technologies for Electric and Hybrid Vehicles
- Editor
- MDPI
- Location
- Basel
- Date
- 2017
- Language
- English
- License
- CC BY-NC-ND 4.0
- ISBN
- 978-3-03897-191-7
- Size
- 17.0 x 24.4 cm
- Pages
- 376
- Keywords
- electric vehicle, plug-in hybrid electric vehicle (PHEV), energy sources, energy management strategy, energy-storage system, charging technologies, control algorithms, battery, operating scenario, wireless power transfer (WPT)
- Category
- Technik