Page - 254 - in Emerging Technologies for Electric and Hybrid Vehicles

Energies 2017,10, 616 4.ResultsofSimulationsofOW-PMSMDriveSystem Weran simulationmodels of theOW-PMSMdrive systemon theMatlab/Simulinkplatform. Thebasicparameters ofOW-PMSMare shown inTable 1 andcontroller parameters are shown in Table 5. API speedcontrollerwasused togenerate the expected torque tomake themotor speed followthepresetvalue. Table5.Parametersofsimulationsettingandcontroller. ModuleAffiliation Item Parameters Modelasawhole TimestepTs/s 5×10−7 Inverterdevices On-resistanceRon/Ω 0.01 Forwardvoltagedropof IGBTVf/V 0.8 ForwardvoltagedropofdiodeVfd/V 0.8 Current fall timeTf/s 1×10−6 Current tailing timeTt/s 1.5×10−6 Windingmodecontroller SamplingtimeTs_MS/s 1×10−4 Sensitivitycoefficientof rotorspeed [ksY,ksΔ] [0.9, 0.9] Sensitivitycoefficientof integral threshold [kIY,kIΔ] [0.35,0.75] PIcontrollerofmotorspeed SamplingtimeTs_SC/s 1×10−4 ProportionalitycoefficientP 0.4 Integral coefficient I 4 MTPAandfluxweakeningcontroller SamplingtimeTs_CC/s 1×10 −4 Voltagesaturationcoefficientku 0.95 Currenthysteresiscontroller SamplingtimeTs_CR/s 1×10−5 Halfwidthofhysteresisbandh/A 3 Maximumswitchingfrequencyofdevices fmax/Hz 1×104 This simulation’sdurationwas0.9 s. In thisprocess, theexpectedmotor rotaryspeed linearly increased to5500r/min in0–0.3 sandstayedat5500r/min till 0.6 s. Thenspeed linearlydropped to 0 in 0.6–0.9 s; loaded torque jumped from0 to50N·mat0.05 s and remained50N·muntil the simulationfinished. In order tomonitor the results of powerdistribution,we shifted the current modulationmethodfromlowswitchingfrequencytohighpowerdifferenceat0.4sandswitchedthe majorpowersource frompowersource1 topowersource2at0.5s.AnotherOW-PMSMdrivesystem under traditional two-levelcurrenthysteresismodulationwithoutwindingmodeswitchingfunction wasalsosimulatedforcomparison. CurvesofexpectedtorqueT∗e , electromagnetic torqueTeofproposedandcontrastmodel, and rotaryspeednm aredemonstrated inFigure6a–c. (a) Expected torque and electromagnetic torque of motor 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 time (s) 0 10 20 30 40 50 60 70 80 90 100 electromagnetic torque expected motor torque Figure6.Cont. 254