Fuel cell with novel Power Conditioning

1
Fuel cell with novel Power Conditioning
Slide of courtesy MTU (Daimler Chrysler). 240 kW
Molten Carbonate HotModule Fuel Cell.
2
Electric Efficiencies of different types of power
plant
3
Hydrogen Economy
4
Principle of the HERPC
DC
AC
AC
AC
Magnetization - DC input Power input ?vp
5
HERPC Stator Rotor Overlap
Stator pole faces
Linearized Stator Rotor interface area
Rotor pole face (rectangle)
Area of overlap
Surface overlap shown at 30º intervals
6
H E R P C
Rotor and stator surfaces meet
Non magnetic rotor parts
Non magnetic spacer
Gearbox
Driving motor
Stator
Principal winding
Magnetic rotor parts
AC phase winding
Principal winding
Cross section (of above) showing three-phase and
principal windings spanning the stator limbs.
AC phase winding
Typical load burden for the device
Typical source of current (iP)
7
Harmonics Efficiency

• Losses
• Joule heating / Core / Friction and Windage /
  Stray
• Controllable with materials dimensions
• Anticipate efficiency similar to large
  synchronous motor

• Harmonics
• Magnetic material nonlinearity / rotor dynamics
• Controllable with materials dimensions
• Anticipate very low harmonic distortion

8
Fuel Cell Power Conditioner HERPC / Chopper
V1 ?ip/?
Fuel Cell matrix
iP
vP
Receiving AC system
Spacer ?
IGBT DC Chopper

• High Power ( high vP x ip )
• High vP series connected Fuel Cells
• High ip must increase ? to maintain ip/? ratio

9
Typical Power Electronic Converter
10
Efficiency of Power Conditioners

• PEC problems
• Substantial fixed losses
• -Transfomer exicitation loss
• - high at low load
• Harmonic source
• HERPC / Chopper advantages
• Fewer processes
• - mains coupling is inherent
• (no additional transformers)
• Variable losses I2

• HERPC
• 2 fixed loss - FW Fe
• 2 variable loss - Cu/Stray
• Average efficiency difference
• over range 4

11
Summary

• HERPC / Chopper proposed for Fuel Cell Power
  Conditioning
• Expected 4 efficiency improvement over PEC
• Commercial incentives are linked to the hydrogen
  economy
• Expected, high efficiency, low distortion, small
  size weight
• HERPC
• No mechanical or electronic commutator no slip
  rings
• Magnetizing DC
• Direct Voltage ? power output

12
Fuel cell with novel Power Conditioning
Questions