Presentation Transcript

1. Basics of power electronics and electric motors for hybrid and electric vehicles

   D.Sc. Tatiana Minav Teaching practice 5.01.2014 Tatiana Minav
2. Behind theory is practice! Tatiana Minav
3. Expectations? wishes? ideas? suggestions? Recommendations? Tatiana Minav
4. Goals/Targets Understandconcept Losses TIER Trends Vehicle classification Ways to improve efficiency Fuel consumption Electric machines types Frequency converters Tatiana Minav
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7. Trends Moremobility - electromobility Highdemand for hybrids Demand for cleanenergy TIER 4 -11 % and <TIER 3 -89 % Fuelquality is low in most of the world Increasemachineefficiency Increaseprocessefficiency Increaseoperatorefficiency Increase life time of Non-road mobile machinery(NRMM) Lowerfuelconsumption Trend to go to highersystemcomplexity System developing and software domination Tatiana Minav
8. Common industrywishes Avoidingpartialload Increasingproductivity Integration Acceptablereturn of investment Reducelosses Tatiana Minav
9. Industry versus Academic research Tatiana Minav
10. HEX market Tatiana Minav
11. Situation of the CE Market Tatiana Minav
12. Main factors for energy efficiency Tatiana Minav
13. Whatkind of losses in car?/ discussion Engine losses Heat losses Mechanical losses(air firction, etc.) Auxillary power consumption (air-conditioning, power steering,etc…) Do you know that ? Total efficiency of an engine is around 20-30 %. How to improve the efficiency? reduce losses optimize the shape or change topology Tatiana Minav
14. Engine efficiency The engine is now in on/off- operation and is only in operation during 11% of the cycle. The other 89%, the engine is switched off, thereby completely eliminating idle losses. Tatiana Minav
15. Vehicleclassification Tatiana Minav
16. Canwemakesomechanges to convertconventionalcar to EV? ? Primemover Engine ? Energy storage Bensin/Gasolin Tatiana Minav
17. GAME-discussion in groups (2-3 pers.) makeyourown EV topology for conventionalcar 5-10 minutes Tatiana Minav
18. Motor Drive System Topologies Central drive Single wheel 2WD drive Single Wheel 4WD drive Final drive 4WD Wheel (hub) drive 4WD Wheel hub drive Tatiana Minav
19. Advantages of a electric motor in hybrid driveline Engine + motor = allows: Smaller engine => less pollution Blue motion => reduce engine idling when stopped The vehicle uses regenerative braking and the internal combustion engine to charge the energy storage Electric motor used as a generator and storing the captured energy in the battery. Extra power during acceleration Tatiana Minav
20. Various Electric Machines
21. Why Electric Machines (EM)? Torque-speed characteristics of EM High torque at low speeds constant torque region High maximum speed
22. Why Electric Machines (EM)? Efficiency of Electric Machines Up to 95 % Efficiency of Internal combustion engines Gasoline up to 30 % Diesel up to 40 %
23. Why Electric Machines (EM)? High efficiency in wide operation area Torque-speed characteristics Fast and accurate control Motor and generator operation modes Regenerative braking Powertrainconfiguration Amount of tractionmotors Challenges Cost -> Manufacturing Size, cooling, etc ? Electricity source ?
24. EM Four-Quadrant Operation
25. Regenerativebraking Potentialfor ~30% energysavings
26. Potential and kineticenergyrecovery in vehicles Kinetic Energy Recovery System (KERS), technology that was introduced to the sport in 2009 and was a mainstay from 2011. http://www.formula1.com/inside_f1/understanding_the_sport/8763.html http://www.toyota-industries.com/csr/environment/product/eco5_9.html Tatiana Minav
27. Group work! Select of EV Topologydepends on application: group1: sport car ( example Ferrari) group 2: familycar(example Volvo) group 3: smallcar(example Fiat) group 4: truck (kuorma-auto) group 5: Bus group 6: non-roadmobile machine – tractor group 7: non-road mobile machine– mineloader
28. Group 1: sportcar what? why? problems? limitations? price? Tatiana Minav
29. Group 2: familycar what? why? problems? limitations? price? Tatiana Minav
30. Group 3: smallcar what? why? problems? limitations? price? Tatiana Minav
31. Group 4: truck what? why? problems? limitations? price? Tatiana Minav
32. group 5: Bus what? why? problems? limitations? price? Tatiana Minav
33. group 6:Tractor what? why? problems? limitations? price? Tatiana Minav
34. group 7: Mineloader what? why? problems? limitations? price? Tatiana Minav
35. Electric Machines (EM) DC Machines Induction Machines Permanent Magnet Machines Switched Reluctance Machines
36. DC Machine Widely used and simple electric motor Technologically mature and simple to control Operation principle: F = BIL T = BIL cos α
37. Animation-DC motor http://www.youtube.com/watch?v=Gzca2CbZ6EM All motors: http://www.animations.physics.unsw.edu.au//jw/electricmotors.html Tatiana Minav
38. Properties of DC Machine Traditionallyused in tractionapplications Trains, trams, electriccars Onlyfullycontrollable EM beforepowerelectronics ~70’s Phased out (in big powerlevels) due to wear of commutator Commutator and slipringbrushesconnectsmagnetizationcircuit to rotorcoils Increasesneed of maintenance Lowefficiencycompared to otherelectricmachines
39. Induction Machine (IM) The most common In tractionapplicationsusually”squirrel-cage” Magnetization current is fed by an inverter Slip (asynchronous machine) Simple and robust
40. Animation http://www.youtube.com/watch?v=LtJoJBUSe28
41. Characteristics of Induction Machine Benefits Reliable and robust Low maintenance, low cost and capability to operate in extreme conditions The most mature technology of AC machines Drawbacks Highloss=> relativelylowefficiency Lowpowerfactor Lowinverterusingfactor (overdimensionedinverter) Losses in rotor (coolingproblem in mobile applications)
42. Operation modes of Induction machine
43. Permanentmagnetmachines (PM) Permanentmagnetrotor Axialfluxrotor ------ > Radialfluxrotor
44. Animation http://www.youtube.com/watch?v=H97HpwZNqZI http://www.youtube.com/watch?v=ZAY5JInyHXY Tatiana Minav
45. Permanent-MagnetRotorConfigurationAffects to T-wCharacteristics PRM Permanent-MagnetAssistedReluctanceSynchronousMachine RM VariableReluctance Machine SPM SurfacePermanent-MagnetSynchronous Machine IPM InteriorPermanent-MagnetSynchronous Machine MR-PM Magnetic-ringPermanent-Magnet Machine M. Arata, N. Takahashi, K. Sakai, K. Hagiwara, T. Araki, Large Torque and High Efficiency Permanent Magnet Reluctance Motor for A Hybrid Truck, EVS-22 Yokohama Japan, 2006
46. Characteristics of PermanentMagnet Machines Advantages: Higherefficiencythan in asynchronousmachine Smallerapparentpower rating for inverter Smaller and lighter design Disadvantages Moreexpensivethanasynchronousorswitchedreluctancemachines Magneticmaterial & manufacturingtechnique Torque is producedby Permanentmagnets Reluctance
47. Switched Reluctance Machine (SRM) Wide speed operation area wmax = 6 to 8 times wnom Different power stage topology as in other electric Simple and robust Iron core and air resistance losses in the rotor machines R. Krishnan, Switched reluctance motor Drives; Modeling, Simulation, Analysis, Design, and Applications, CRC Press, London, 2001
48. Animation http://www.freescale.com/webapp/sps/site/overview.jsp?code=WBT_MOTORSRTUT_WP A switched reluctance motor does not contain any permanent magnets. The stator is similar to a brushless dc motor. The rotor consists only of iron laminates. The iron rotor is attracted to the energized stator pole. The polarity of the stator pole does not matter. Torque is produced as a result of the attraction between the electromagnet and the iron rotor. Tatiana Minav
49. Characteristics of the Switched Reluctance Machine Benefits Simple and ruggedstructure Fault-tolerantoperation Simplecontrol Verygoodtorque-speedcharacteristics Drawbacks Acousticnoise Torque and currentripple Specialconvertertopology Electromagneticinterference
50. Switched Reluctance Machine with Integrated Flywheel and Clutch
51. Best attributes of electricmachines Robust and simple: Inductionmachine Switchedreluctancemachine (SRM) Lowcost Inductionmachine (SRM in the future) Efficient Permanentmagnetmachines
52. Comparison of electric machines Great torque-speedcharacteristics Switchedreluctancemachine Weight, Size Power density Permanentmagnetmachines Controllability-> applicable to vehicleapplications DC-machine Inductionmachine PM machine
53. Weaknesses in usefulness point of view Short speed-operationrange of permanentmagnetmachines Need of gearboxifused in highspeedvehicles Limited availability of switchedreluctancemachines Price: smallmarket -> smallproduction -> highcost
54. Typical Efficiency Characteristics of HEV Traction Motors Accurateefficiencyvaluesdependfrompower, voltageratings and machinetype Maximum efficiencyusuallyaround 90 to 95 % Asynchronous machine Switched reluctance machine Surface-permanentmagnetmachine Interior-permanentmagnetmachine S.S.Williamson, S.M.Lukic, A.Emadi, Comprehensive Drive Train Efficiency Analysis of Hybrid Electric and Fuel Cell Vehicles Based on Motor-Controller Efficiency Modeling, IEEE Trans. Power Electron., vol. 21, no. 3, pp. 730-740, May 2006
55. Group work! Select of Electric Machine depends on application: group1: sport car ( example Ferrari) group 2: familycar(example Volvo) group 3: smallcar(example Fiat) group 4: truck (kuorma-auto) group 5: Bus group 6: non-roadmobile machine – tractor group 7: non-road mobile machine– mineloader
56. Discussion: Whatweshouldconsider? Neededtorque–speedcharacteristics Torque at lowspeeds (constanttorqueregion) Maximum speed Maximum speedrelation to nominalspeed (wmax/wnom) Constanttorqueregion Fieldweakeningregion Highvalue to achievegearlessoperation Magnetizationmethod Reluctancetorque Control of powerelectronics Location: Powertrainconfiguration Amount of tractionmotors Cost, size, cooling, etc.
57. Group 1: sportcar What Motor type? Cooling? why? problems? limitations? price? Tatiana Minav
58. Group 2: familycar What Motor type? Cooling needed? why? problems? limitations? price? Tatiana Minav
59. Group 3: smallcar What Motor type? Cooling needed? why? problems? limitations? price? Tatiana Minav
60. Group 4: truck What Motor type? why? problems? limitations? price? Tatiana Minav
61. group 5: Bus What Motor type? Cooling needed? why? problems? limitations? price? Tatiana Minav
62. group 6:Tractor What Motor type? why? problems? limitations? price? Tatiana Minav
63. group 7: Mineloader What Motor type? Cooling needed? why? problems? limitations? price? Tatiana Minav
64. Near-wheelmotor (LUT) The designed PMSM rotor structure comprises two permanent magnet layers embedded inside the rotor laminations. The PMSM can produce nominal torque with the nominal current in a wide speed range. the nominal torque is 240 Nm. Tatiana Minav Source: ICEM 2012 J.Nerg, Design of Direct-Driven Permanent Magnet Synchronous Motors for an Electric Sports Car
65. In-wheelmotor/ hubmotor Like so many things, in-wheel motors have already been done, but technology and our ability to integrate them into wheels has changed a lot since the first in-wheel motor (also called a hub motor) was patented back in 1884 and, after disappearing for decades, they are starting to creep back into vehicle. Tatiana Minav
66. In-wheelmotor High-efficiency Direct drive Regenerativebraking Integration No transmission ordriveshafts Example: Proteanelectronics: -built-ininverter and controlelectronics http://www.youtube.com/watch?v=8tLQ2-yKT4Y Tatiana Minav
67. Source: http://www.proteanelectric.com/wp-content/uploads/2011/12/2012_HTUF_-_Hybrid-Retrofit_Opportunities1.pdf Tatiana Minav
68. How to control electric machine? Tatiana Minav
69. MOTOR CONTROL Torquecontrol in widespeedrange Speedcontrol Position control POWER ELECTRONICS is required for motorcontrol
70. What is Power Electronics (PE) ? Efficientuse of electricdrives and energystorages Controllablecurrent-voltageratio Electric hassmall inertia vs. hydrauliccomponents Power electronicsystemsconvertsupply’s electricenergy into a formsuitable for the load DC to variable AC E.g. frombattery to electricmachine, and AC to DC E.g. regenerativebraking E.g. fromgenerator to energystorageor DC link DC to DC E.g. frombattery to highvoltage DC link
71. Classification of Power Processors and Converters
72. Power Electronics (PE) Enabling technology for electric and hybrid vehicles High efficiency in wide operation area Control of electric machines Motor and generator operation modes Regenerative braking Challenges Cost -> Manufacturing Cooling -> size, lifetime Semiconductorsmaxtemperature 120 – 175 degC Need for additionalcoolingcircuit
73. Challenges in Power Electronics Highefficiency (lowlosses) powerlossesconvert into heat, whichyields to excessivecooling and thermalsizing of components price of electricenergy and coolingsystem Small size of products highefficiency is crucial coolingelementsarebulky and heavy packagingdensity, integration of power and controlcomponents Competitiveprice 3rd gen. 2nd gen.
74. What are little converters made of… IGBT
75. What are little converters made of…
76. What are little converters made of…
77. Example: AC Motor Drive Converter 1 rectifiesline-frequency AC into DC Capacitoracts as a filter and decouples the twoconvertercircuits Converter 2 producesvariable-frequency AC for the motor Polarity of DC voltagelinkremainsunchanged
78. RelatedTopics Electric Drives control of drives, choice of motor and converter Industrial Electronics electronics, signalprocessing, measurementtechniques, soft computing Electromechanics Control engineering Electromagnetics Power Systems
79. DC–DC Converters DC–DCconvertersareused in Betweendifferent DC voltagelevels (e.g. energystorage and regulatedDC-link) Power supplies DC motordrives The aim is to providepreciselycontrolledoutput voltageorcurrent
80. DC–DC Converters Single quadrant oneactiveswitch, onediode, inductance and smoothingcapacitance Buck, stepdown, vout ≤ vin Boost, stepup, vout ≥ vin Buck-boost, combination Twoquadrant E.g. bidirectionalboostconverter Fourquadrant
81. DC–DC Converter Applications in Vehicle Environment Batterycharger / energystorageconverter Fuelcellconverter Heaters Power supplies for controlelectronics auxiliarydevices
82. AC-DC RECTIFIERS AND DC-AC INVERTERS are used in Traction motor control Generator control (engine series-hybrids) Other AC-supplies Pumps Fans
83. 1-phase inverter http://www.ipes.ethz.ch/ipes/e_index.html
84. Four-QuadrantConverter (DC drive) http://www.ipes.ethz.ch/ipes/MaschineDC/e_kreis.html Tatiana Minav
85. Transmission/Gear box Gearbox is used to slow down the output speed and increase torque. In conventional car internal combustion engine typically operate over a range of 600 to 7000 rpm, while the car's wheels rotate between 0 rpm and around 1800 rpm. Direct transmissions: Manual, Semi-Automatic Automatic. Non-direct transmissions: electric, Hydrostatic hydrodynamic. T.A.Minav
86. Transmission/Gear box Electric equivalent Dynamic machine operation envelops electric torque versus mechanical speed a) Parallel connection of phases, b) series connection of phases T.A.Minav
87. ElectrciaclTransmission/Gearbox The presented principle is applied to a non-salient permanent magnet synchronous machine (PMSM), with six phases of which three sets of each two phases are driven with the same current, resulting in a balanced three-phase machine structure T.A.Minav
88. Full-bridge Schematic representation of the two coils per phase, full-bridge per coil circuit capable of driving the coils individually or connected in series. T.A.Minav
89. Conclusion Now you Know what's EM is and what control it :) Tatiana Minav
90. New Group division! Count from 1 to 6. Tatiana Minav
91. Homework 1 Group 1: Batteries: Lead acid Group 2: Batteries: Lithium Group 3: Super capacitor Group 4: Fuel cell Group 5: Flywheel Group 6: Hydraulic accumulator read articles according to your group number and answer questions: Advantages and Disadvantages of energy storage? Price of energy storage? Availability on the market? Possible applications? limitations? Tatiana Minav
92. Homework 2 Exersises 2 available on Noppa return before 21.1 Tatiana Minav
93. Feedback Tatiana Minav tatiana.minav@aalto.fi Tatiana Minav