Advisors: Renee Kohl Dr. Woonki Na Peter Burrmann Dr. Brian - - PowerPoint PPT Presentation

▶
advisors renee kohl dr woonki na peter burrmann dr brian
SMART_READER_LITE
LIVE PREVIEW

Advisors: Renee Kohl Dr. Woonki Na Peter Burrmann Dr. Brian - - PowerPoint PPT Presentation

Mar 18, 2023 128 likes •648 views

Advisors: Renee Kohl Dr. Woonki Na Peter Burrmann Dr. Brian Huggins Matthew Daly 1 Why the electric car? Reduce our foreign oil dependence Reduce carbon emissions 2 Outline Functional Description Progression of Project

slide-1
SLIDE 1

Renee Kohl Peter Burrmann Matthew Daly Advisors:

  • Dr. Woonki Na
  • Dr. Brian Huggins

1

slide-2
SLIDE 2

Why the electric car?

 Reduce our foreign oil dependence  Reduce carbon emissions

2

slide-3
SLIDE 3

Outline

 Functional Description  Progression of Project

 Implementation/Construction  Testing

 Results

3

slide-4
SLIDE 4

Project Summary

 Convert 120 volt AC grid power to the required 51.8[V]

DC value to efficiently charge an electric vehicle battery

 Discharge battery via Bi-directional converter into a

variable load

120V AC Diode Rectifier AC/DC Boost Converter DC/DC PFC Bidirectional Converter DC/DC 51.8V Battery DSP PWM PWM Load Discharging or charging? Charging Discharging

4

slide-5
SLIDE 5

Project Goals

 Create a PHEV charging system capable of outputting

up to 1k[W] of power for the operation of a variable load.

 Implement a control system using a DSP for the

purpose of driving MOSFET gates

 Efficiently Charge a Li-Ion battery using our power

electronics system

5

slide-6
SLIDE 6

Diode Rectifier

120V AC

Diode Rectifier Boost Converter Bidirectional Converter

51.8V Battery

DSP

PWM PWM Load Discharging or charging? Charging Discharging

6

slide-7
SLIDE 7

Functional Description

Diode Rectifier

 Rectifies 120[Vrms]

AC grid power

 Precedes Power

Factor Correction

7

slide-8
SLIDE 8

Functional Description

Diode Rectifier

8

slide-9
SLIDE 9

Power Factor Correction

120V AC

Diode Rectifier Boost Converter PFC Bidirectional Converter

51.8V Battery

DSP

PWM PWM Load Discharging or charging? Charging Discharging

9

slide-10
SLIDE 10

Power Factor Correction

 Power Factor

 Dimensionless number from 0-1  Ratio of real to apparent power  1 is in unity (ideal)

 Passive power factor correction- Capacitor, Inductor  Active power factor correction- Boost Converter

10

slide-11
SLIDE 11

Implementation

Diode Rectifier / Power Factor Correction

11

slide-12
SLIDE 12

Bi-Directional Converter

120V AC

Diode Rectifier Boost Converter Bidirectional Converter

51.8V Battery

DSP

PWM PWM Load Discharging or charging? Charging Discharging

12

slide-13
SLIDE 13

Functional Description

Bi-directional Converter

 To be used in place of the individual Buck and Boost

converters’ architecture

 Requires more detailed control system

13

slide-14
SLIDE 14

Implementation

Bi-Directional Converter

14

slide-15
SLIDE 15

Functional Description

Buck Converter

 Drops input voltage

based on MOSFET Duty cycle

 Half of the Bi-

directional Converter

Stage 1 Stage 2

15

slide-16
SLIDE 16

Functional Description

Boost Converter

 Boosts input voltage

based on MOSFET duty cycle

 Part of Power Factor

Correction

 Half of Bi-directional

Converter

Stage 1 Stage 2

16

slide-17
SLIDE 17

Implementation PFC and Bi-Directional Converter

17

slide-18
SLIDE 18

Functional Description

Interfacing & Protection Circuitry

 To be used to sense voltage levels from various

locations of the PHEV system, while providing isolation between the DSP and high voltage levels

18

slide-19
SLIDE 19

Functional Description

Gate Driver

 Receives PWM input from DSP

to control switching of MOSFETs

 Provides enough power to drive

the converter’s MOSFETs

19

slide-20
SLIDE 20

Functional Description

Gate Driver

Bootstrap Capacitor

Qg = Gate Charge f = Frequency of Operation Iqbs(max) = Maximum Vbs Quiescent Current Qls = Level Shift Charge (5nC) Icbs(leak) = Leakage Current Vcc = Logic Section Voltage Source Vf = Forward Voltage Drop Across Bootstrap Diode VLS = Voltage Drop Across Low- Side FET Vmin = Minimum Voltage Between Vb and Vs

g g g s g g

I V R T Q I = =

20

slide-21
SLIDE 21

120V AC

Diode Rectifier Boost Converter PFC Bidirectional Converter

51.8V Battery

DSP

PWM PWM Load Discharging or charging? Charging Discharging

Battery

21

slide-22
SLIDE 22

Functional Description

Battery

 Working Voltage=51.8[V]  14 Cell Polymer Li-Ion  Capacity = 10Ah (518Wh)  40[A] Continuous

Discharge Rate

22

slide-23
SLIDE 23

Functional Description Battery

23

slide-24
SLIDE 24

Implementation

Charging Method

 Stage 1: Charge Rate: 0.8C

 Constant Current Method

 Stage 2: 58.8[V]

 Constant Voltage Method  Terminate at 3% Rated Current

 No Trickle Charge

 Reduces battery life

24

slide-25
SLIDE 25

Implementation

Battery Resistance

 Internal Resistance varies

with State of Charge

 Actively Measure State of

Charge

 Coulomb Counting

 Requires Current Shunt

25

slide-26
SLIDE 26

 RC Battery Model  Allows for Matlab simulation  Resistance values are functions of SOC, T, and

charge/discharge

Implementation

Measuring Battery Resistance

26

slide-27
SLIDE 27

Implementation

Measuring Battery Resistance I V V I V V R

2 3 terminal

  • c

− = − =

 Internal Resistance seen

from pulse discharge

 Rint = 108m[Ω]

Vr 56.530 R 10.910 V1 57.850 V2 57.160 V3 57.720 I 5.181 Rint 0.108

27

slide-28
SLIDE 28

Implementation

Measuring Battery Resistance

28

slide-29
SLIDE 29

Bi-Directional Converter

120V AC

Diode Rectifier Boost Converter Bidirectional Converter

51.8V Battery

DSP

PWM PWM Load Discharging or charging? Charging Discharging

29

slide-30
SLIDE 30

Schematics

 Buck Converter

30

slide-31
SLIDE 31

Calculating gains

Fc=500Hz 15dB

  • 150°

31

slide-32
SLIDE 32

Psim output voltage

32

slide-33
SLIDE 33

Buck Converter PI Control

6.12 voltage divider limit duty cycle inverter C281x PWM W1 PWM 0.1 Kp .00073 Gain4 F2812 eZdsp1 K Ts z-1 Discrete-Time Integrator 100 Constant2 10 Constant C281x ADC A ADC1

33

slide-34
SLIDE 34

PI Control

34

slide-35
SLIDE 35

Schematics

 Boost Converter

35

slide-36
SLIDE 36

Boost Converter PI Control

6.12 voltage divider limit duty cycle inverter C281x PWM W1 PWM 0.1 Kp .00073 Gain4 F2812 eZdsp1 K Ts z-1 Discrete-Time Integrator 100 Constant2 10 Constant C281x ADC A ADC1

36

slide-37
SLIDE 37

PI Control

37

slide-38
SLIDE 38

Power Factor Correction

120V AC

Diode Rectifier Boost Converter PFC Bidirectional Converter

51.8V Battery

DSP

PWM PWM Load Discharging or charging? Charging Discharging

38

slide-39
SLIDE 39

Power Factor Correction

 How it works:

39

slide-40
SLIDE 40

Schematics

Power Factor Correction

40

slide-41
SLIDE 41

PFC Testing

 Channel 1: output of current

sensing circuitry and op amp input to the dsp

 Channel 2: output of current

probe

 Open loop control, 50% duty

cycle

 80mV out of the op amp can be

converted by multiplying by the 1.25 voltage divider, then multiply by 50/4 for the current sensor, and divide by 5 to factor in the 5 loops around the current sensor gives you 250mV which the current probe is showing.

41

slide-42
SLIDE 42

PFC Testing

 Because the current being measured by the DSP is a rectified sign wave

with an amplitude of approximately 80mV, I simulated this in Simulink as the reference current to match.

42

slide-43
SLIDE 43

PFC Testing

 1: output of current sensing

circuit opamp into DSP

 2: current probe measuring

current through inductor

 1: constantly adjusting pwm

43

slide-44
SLIDE 44

PFC PI Control

2 voltage divider3 6.7 voltage divider1
  • K-
voltage divider limit duty cycle inverter In1 Out1 iir filter2 In1 Out1 iir filter1 Product C281x PWM W1 PWM
  • K-
Kp2
  • K-
Kp1 .00073 Gain4 .00073 Gain2 .00073 Gain1 F2812 eZdsp1 K Ts z-1 Discrete-Time Integrator2 K Ts z-1 Discrete-Time Integrator1 double Data Type Conversion3 uint16 Data Type Conversion2 double Data Type Conversion1 double Data Type Conversion 100 Constant2 15 Constant1 C281x ADC A4 A3 A5 ADC1

44

slide-45
SLIDE 45

PFC PI Control

 Circuit in discontinuous

mode

45

slide-46
SLIDE 46

Completed Work

 Designed full scale system  Controls functioning

 Full scale boost converter  Full scale buck converter  Small scale PFC

46

slide-47
SLIDE 47

Future

 Use system to charge battery  Acquire detailed parameters for battery  Discharge battery through inverter to run a variable

load

 Implement regenerative braking  Utilize ultra-capacitors for regenerative braking energy

storage

47

slide-48
SLIDE 48

Questions?

48

slide-49
SLIDE 49

Converter Equations

Capacitor and Inductor Calculation Equations for PFC and Bi-Directional Converter Voltage Divider Boost Converter Buck Converter

49

slide-50
SLIDE 50

Controller Equations

50

slide-51
SLIDE 51

MOSFET vs. IGBT

51