Power Electronics for Electric Drive Vehicles. Fall 2013

Transcription

1 Power Electronics for Electric Drive Vehicles Fall

2 Course Offered Jointly Co developed and maintained by multiple universities USU: Prof. Regan Zane (lead for 2013) CU Boulder: Prof. Dragan Maksimovic University of Cantabria, Spain: Prof. Francisco Azcondo Content provided by all campuses Lectures, assignments, supplementary video and materials Local support: office hours, grading, location specific details Benefits Course content maintained relevant and up to date Leading experts brought in from around the world Online content available to all students for review Discussions exchanged across campuses via course blog 2

3 CU Boulder Instructor: Professor Dragan Maksimovic Office: OT346, 3 rd floor office tower phone: Office hours Monday, Wednesday 1 2:30pm Class blog E mail: maksimov@colorado.edu Please use 5017 in the subject line 3

4 Materials and Textbook Course website Lecture slides & notes, assignments, additional materials Textbook R. Erickson, D. Maksimovic, Fundamentals of Power Electronics, Springer 2001 (Chapters 1 5); on line access available from CU network MATLAB/Simulink is required Student version is sufficient Prerequisites undergraduate circuits sequence, microelectronics, Laplace transforms, linear systems 4

5 Assignments Weekly homeworks (11 12 total), 50% of the grade Midterm exam (open book/notes, take home), 20% of the grade Final exam (comprehensive, open book/notes, take home), 30% of the grade All assignments and due dates posted on the course web site All work must be submitted via D2L system as a single, easily readable PDF file; use black an white scanning, reasonable file size Deadlines are enforced by D2L and are the same for all students, on campus and off campus Late work will not be accepted except in cases of documented emergencies 5

6 Homeworks Exams Assignment Policy You are encouraged to talk to other students taking the class about homework problems; collaboration is allowed Use the class blog to ask and answer questions You must turn in your own work. Copying someone else s work is not allowed Take home, open book, open notes exams Absolutely no collaboration allowed in any form Any policy violations would lead to severe consequences, starting with an immediate F in the class, for all parties involved 6

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8 How to succeed in this course Keep up: follow all materials available online Actively participate: speak up in class, post questions and answers to blog Class attendance is required Plan on a significant effort in the weekly homework assignments Review for the mid term and final exams similar to any other exam Plan on increased effort during the one week take home exams 8

9 Introduction Objectives Architectures, modeling and simulations of electric drivetrains Modeling, analysis and design of vehicle power electronics One of the four courses in Graduate Certificate in Electric Drivetrain Technology offered by UCCS 9

10 Transportation electrification System overview Course Outline Vehicle dynamics, MATLAB/Simulink modeling Architectures of hybrid (HEV), plug in hybrid (PHEV) and electric vehicles (EV) Rating and sizing of drivetrain components Electric drivetrain components: analysis, modeling, simulations and design considerations Battery systems, battery management electronics Bidirectional DC DC converters Inverters and AC motor drives Battery chargers Complete system modeling and simulations 10

11 System Architectures, Modeling and Simulations Top-Level EV Model Top-level model of EV for use in ECEN 5017 course. Driving cycle is a velocity-vs-time profile for the vehicle, operating on flat ground. Driver uses gas pedal to track the reference velocity. Vehicle Speed Driv ing cy cle Ref erence Speed Torque command (Gas & brake pedals) Vehicle Monitoring m speeds Forces Iinv Driver model Electric Vehicle Vref Ebat dist Unit Conversion Scope Vehicle dynamics, MATLAB/Simulink modeling Architectures of hybrid (HEV), plug in hybrid (PHEV) and electric vehicles (EV) Rating and sizing of drivetrain components 11

12 Vehicle Subsystems Electrical Model View Simulink Model View Inverter Input Current Rotor Angular Speed EV Battery Model: Functional Battery Voltage DC Bus Voltage 1 1 Iinv Tcommand 3 Vbus_ref SOC Bus Voltage DC-DC Converter: 2 Reference Functional Motor Drive Inverter: Iabc Functional PMAC Motor: Functional Motor Torque Gearing Wheel Torque 2 Vev Wheel Angular Speed Tire 4 Fdrive Battery Current Motor Input Power Rotor Phase Angle Vehicle Systems Model Model for a sample vehicle system during driving cycle. Model consists of Battery, DC-DC, Inverter, three-phase Permanent-Magnet AC (PMAC) motor, drive shaft gearing, and vehicle tires 12

13 Energy Storage System (Battery) An introduction to battery electrochemistry Types and characteristics of battery cells, energy, power, cycle life, calendar life, cost Cell charge/discharge characteristics, electrical circuit modeling Battery management system, cell balancing Modeling and simulations of battery systems Battery dynamic modeling and control are covered in IDEATE courses at UCCS ECE 5710: Modeling, Simulation, and Identification of Battery Dynamics (Fall) ECE 5720: Battery Management and Control (Spring) 13

14 Bidirectional DC DC Converter Introduction to switched mode power converters Steady state operation, analysis and simulations Introduction to power semiconductor switching devices: diodes, IGBTs, MOSFETs Modeling of losses and efficiency Simulations This course provides a self contained introduction and covers additional topics specific to electric drivetrain applications Topics covered in more detail in ECEN 5797: Introduction to Power Electronics 14

15 AC Motor Drive An introduction to AC machine operation and models* Permanent magnet synchronous machine Induction machine DC to AC inverter operation and controls AC drive modeling and simulations * Topics covered in more detail in ECEN 5737: Adjustable Speed AC Drives offered in Spring 2014 at CU Boulder 15

16 Complete System Model and Simulations Top-Level EV Model Top-level model of EV for use in ECEN 5017 course. Driving cycle is a velocity-vs-time profile for the vehicle, operating on flat ground. Driver uses gas pedal to track the reference velocity. Speed Vehicle Speed Torque command (Gas & brake pedals) speeds Driving cycle Ref erence Speed Vehicle Monitoring m Forces Iinv Driver model Electric Vehicle Vref Ebat dist Unit Conversion Scope Forces The course includes Integration of developed subsystem models into a complete vehicle model System evaluation and design considerations Inverter current Battery energy 16

17 Transportation Electrification Motivation Improve efficiency: reduce energy consumption Displace petroleum as primary energy source Reduce impact on environment Reduce cost EIA: Transportation accounts for 28% of total U.S. energy use Transportation accounts for 33% of CO2 emissions Petroleum comprises 93% of US transportation energy use 17

18 Example: US06 driving cycle Vehicle speed [mph] v [mph] min 8 miles P v [kw] Propulsion power [kw] Example: Prius sized vehicle time [s] 18

19 Average power and energy v [mph] P v [kw] time [s] Prius sized vehicle Dissipative braking P vavg = 11.3 kw 235 Wh/mile Regenerative braking P vavg = 7.0 kw 146 Wh/mile 19

20 Conventional versus Electric Vehicle (Prius sized vehicle example) Tank + Internal Combustion Engine (ICE) Electric Vehicle (EV) Battery + Inverter + AC machine Regenerative braking NO YES Tank to wheel efficiency Energy storage Refueling Cost CO 2 emissions (tailpipe, total) 20% 1.2 kwh/mile, 28 mpg Gasoline energy content 12.3 kwh/kg, 33.7 kwh/gallon 5 gallons/minute 11 MW, 140 miles/minute 12 /mile [$3.50/gallon] 300, 350) g CO 2 /mile 85% 0.17 kwh/mile, 200 mpg equiv. LiFePO 4 battery 0.1 kwh/kg, 0.8 kwh/gallon Level I (120Vac): 1.5 kw, <8 miles/hour Level II (240Vac): 6 kw, <32 miles/hour Level III (DC): 100 kw, <9 miles/minute 2 /mile [$0.12/kWh] (0, 120) g CO 2 /mile [current U.S. electricity mix] 20

21 Electric Drive Vehicle Technologies Internal Combustion Engine (ICE) vehicle Gasoline powered only Hybrid Electric Vehicle (HEV) Combination of a gasoline powered ICE and electric drive, HEV efficiency improvements Regenerative braking Downsizing: a smaller, more efficient ICE, relatively small battery ICE operated around the most efficient operating point No idling required when the vehicle stops, keep ICE off Plug In Hybrid Electric Vehicle (PHEV) Same efficiency improvements as HEV Larger battery for an all electric range Electric Vehicle (EV), All electric vehicle (AEV), (BEV) No ICE, (much) larger battery 21

22 PHEV example, new EPA stickers Chevy Volt EPA miles per gallon equivalent calculation for All Electric 1720 kg 62 kw (83 hp) ICE 55 kw generator 110 kw (149 hp) electric drive 16 kwh Li Ion battery (175 kg) 65% usable, 35 mi EV range 8 years, 100,000 miles warranty MPG equivalent = Trip length [miles] Total energy consumed [kwh] x 33.7 kwh/gallon 22

23 EV example Nissan Leaf 1527 kg 80 kw (110 hp) electric drive 24 kwh Li Ion battery Cells: 140 Wh/kg 300 kg battery pack (8 years, 100,000 miles warranty) 23

24 CO 2 emissions and oil displacement study Well to Wheel Analysis of Energy Use and Greenhouse Gas Emissions of PHEVs (2010 report by Argonne National Lab) 24

25 CO 2 emissions Over Full Lifetime Preparing for a Life Cycle CO 2 Measure (2011 report by Ricardo)

26 Trends and Challenges Paths to electrified (personal) transportation Hybrid electric vehicles (HEV) Plug in hybrid electric vehicles (PHEV) All electric vehicles (AEV, BEV) Hydrogen + fuel cell electric vehicles (FCV) Electricity generation mix: shift to renewables Challenges Batteries Engineering of electric drivetrain components, including efficient, high density, reliable power electronics Charging infrastructure 26

27 A Vision: Renewable Sources + Battery Electric Vehicles P chg Zero GHG emissions, no petroleum High efficiencies are feasible: 80% grid to wheel Challenges Battery technology: cost, cycle life, power and energy density Efficient, reliably and cost effective drivetrain components Need for charging infrastructure Limited P chg, long charge up times 27