Presentation2(fuel Cell Application Research)

Power Flow Management of an Electric Wheelchair Using a Fuel Cell and EDLC

　　 Anyapo Chan 　 ID: 08502982

Department of Electrical Engineering

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Presentation contents

1. Introduction 2. Research background 3. The problems of previous research 4. The objective of this research 5. System design configuration 6. Research process 7. Expected outcome 8. Conclusion 2

1.Introduction

What is a fuel cell?

Electrolyte

Cathode

Anode

- High efficiency power conversion. - Virtually silent operation. - No pollutant emission.

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　　　　　　　　 What is EDLC? 

EDLC (Electric Double Layer Capacitor) is device that is used to store energy.



EDLC has lower inner resistance. Longer life, faster charging and discharging.



Photograph of EDLC

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2.Research background My previous research has focused on developing an electric wheelchair using a fuel cell. DC Motors

Electric wheelchair

Fuel cell

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The original system

Motors Driven Circuit Fuelcell cell Fuel type Maximum power output Rated voltage

PEM 200 W. 24V.

Motor type Power Rated voltage

DC MOTOR

DC MOTOR

DC 90 W. 2 4V. 6

3. 　 Problems of the previous research. 3.1 Fuel cell voltage is not constant. Real Voltage

30

Output voltage (V)



Ideal Voltage

25

20

15 0 0

5

10

15

Output current (A) 7

3.2 　 Fuel cells have a very slow dynamic response. I

Load T

I

Fuel Cell t1

t2

t3

t4

T

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3.3 　 A fuel cell shuts itself down and it will be 　 　　　　 damaged if it is shutdown many times. Voltage

200

Output voltage (V)

25

Power

20

150

100

15

50

0 0

5

10

Output power (W)

30

0 15

Output current (A) 9

3.3 　 A fuel cell shuts itself down and it will be 　 　　　　 damaged if it is shutdown many times.

Damage!!! Fuel cell

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4. 　 The objective of this research 4.1 　 To design a power electronics interface 　 between a fuel cell and a motor Motor driven Fuel unit. Cell Driven unit

Energy Buffer device

EDLC

4.2 　 To manage power flow in the system. 11

5. System design configuration 1st Step 3rd Step

2ndStep DC Chopper

Bi-Directional converter Q1

Q3

Q5

Motor

+

Oxygen

M

Blower

Electric valve

-

Left

Q2

Fuel Cell Stack

Hydrogen Absorbing Alloys

EDLC

Hydrogen Flow Control

Air Flow Control

Q4

-

M

+

Right

Q6

Final Step

Bi-Directional converter Control

Motor Control

Central Control &Power Flow Management Unit

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6.Research process 6.1 Experimental study of Fuel cell characteristics. Open circuit 40 35

Rohm

30

Fuel cell voltage(V)



Zone A

25

Rconc

Zone B

20

　　 R

act

Zone C

15 10

C

IFC VFC

RLOAD

VM

5 0 0

2

4

6

8

10

12

14

16

Fuel cell current(A)

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6.2 　 Designing Bidirectional Converter.

Fuel cell

Energy Buffer device

EDLC (Electric Double layer capacitor) 14

6.3 　 To experiment an oxygen flow and hydrogen 　　 　　　 flow. Hydrogen pressure=0.025MP a(constant)

V B =8V

V B =12V

160

V B =16V V B =20V

Output power(W)

140

Oxygen

Motor

120

Humidity=75.8% O Temperature=16.3 C

100

Blower 80 60

Fuel Cell Stack

Electric valve

40 20 2

3

4

5

6

7

8

9

10

Hydrogen flow rate(l/ m)

Hydrogen Absorbing Alloys

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6.4 　 To design the central control and 　 power flow management  To investigate unit. all operations  

 

conditions. To design control system. To simulate the system by using computer programming. To make the real system. To experiment the real system. 16

7. 　 Expected outcome 





The electric wheelchair will be able to run by using fuel cell for stabilization of power. The system of the electric wheelchair can save energy as much as possible. The system has high efficiency power conversion. 17

8. 　 Conclusion   

 

To study the characteristics of fuel cell. To improve the system for stabilization. To manage power in the system for saving as much power as possible. To improve the efficiency of power conversion system. Knowledge whish is obtained from this study can be

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I will welcome your comments and criticisms.

Thank you 19