Page - 329 - in Emerging Technologies for Electric and Hybrid Vehicles

Energies 2017,10, 315 Figure4. 3-DEMsimulationmodelof thesourcecoilandloadcoilandtheirdimensionalparameters (incm). Table1.Parametersetupfor the3-DEMsimulation. Parameter SourceCoil LoadCoil SensorCoil #of turns 8 50 10 Inductance 116μH 2.35mH 732nH Operatingfrequency 20kHz Current throughsourcecoil 200A Thesimulationwasconductedtoobserve thechanges inM,kandthe loadcoil’s receivedpower resultingfromalateralmisalignmentof−50cmto50cm,andalsoanangularmisalignmentof0,10, and20degrees relative to the zaxis. The simulationonly consideredanangularmisalignmentup to20degrees,becauseanangularmisalignmentgreater thanthestatedvaluecanbeconsideredan extremesteeringangle foravehiclemovingathighspeeds. Thechanges inM, andk fromthe lateralandangularmisalignmentsareshowninFigure5. There areslightvariationswith increasedangularmisalignment,but it canbeseenthat lateralmisalignment is thedominant factor inreducingM.Therefore, theproposedACASwasdesignedtominimize lateral misalignment to allowhigherM so that higherpowerwill be receivedat the load coil, increasing overall efficiency. Figure 5. 3-D EM simulation result showing the change in themutual inductance and coupling coefficientdueto lateralmisalignmentandangularmisalignment. 3.Conceptof theAutonomousCoilAlignmentSystem(ACAS) Figure6 showsageneral blockdiagramof theproposedACAS. It isdivided into threeparts: the ACAS sensor coil unit, the lateral position detection unit, and the fuzzy steering controller. The lateral misalignment position is estimated by the sensor coil unit and further processed by the lateralmisalignmentdetectionunit. Basedonthedetected lateralmisalignment, the fuzzysteering controllerwill sendsteeringcommands to theelectronicpowersteeringsystem(EPS), afterwhich the vehicle is steeredautonomously tocorrect themisalignment. EPS isalreadyused inmostEVsand isbeingequipped inmostnewlymanufacturedcommercialvehiclesaswell. In caseanobstacle is 329