04-01-2013, 01:58 PM
Dynamic Models and Model Validation for PEM Fuel Cells Using Electrical Circuits
[attachment=46471]
Abstract—
This paper presents the development of dynamic
models for proton exchange membrane (PEM) fuel cells
using electrical circuits. The models have been implemented
in MATLAB/SIMULINK and PSPICE environments. Both the
double-layer charging effect and the thermodynamic characteristic
inside the fuel cell are included in the models. The model
responses obtained at steady-state and transient conditions are
validated by experimental data measured from an Avista Labs
SR-12 500-W PEM fuel-cell stack. The models could be used in
PEM fuel-cell control related studies.
INTRODUCTION
PROTON EXCHANGE MEMBRANE (PEM) fuel cells
show great promise for use as distributed generation (DG)
sources. Compared with other DG technologies, such as wind
and photovoltaic (PV) generation, PEM fuel cells have the
advantage that they can be placed at any site in a distribution
system, without geographic limitations, to achieve the best
performance. Electric vehicles are another major application
of PEM fuel cells. The increased desire for vehicles with less
emission has made PEM fuel cells attractive for vehicular
applications since they emit essentially no pollutants and have
high-power density and quick start.
PEM fuel cells are good energy sources to provide reliable
power at steady state, but they cannot respond to electrical load
transients as fast as desired. This is mainly due to their slow
internal electrochemical and thermodynamic responses. The
transient properties of PEM fuel cells need to be studied and analyzed
under different situations, such as electrical faults on the
fuel-cell terminals, motor starting, and electric vehicle starting
and acceleration.
DYNAMIC MODEL BUILT IN MATLAB/SIMULINK
A dynamic model for the PEM fuel cell has been developed
in MATLAB/SIMULINK, based on the electrochemical and
thermodynamic characteristics of the fuel cell discussed in
Section III. The fuel-cell output voltage, which is a function
of temperature and load current, can be obtained from the
model. Fig. 3 shows the block diagram, based on which the
MATLAB/SIMULINK model has been developed. In this
figure, the input quantities are anode and cathode pressures,
initial temperature of the fuel cell, and room temperature. At
any given load current and time, the internal temperature is
determined and both the load current and temperature are fed
back to different blocks, which take part in the calculation of
the fuel-cell output voltage.
EQUIVALENT ELECTRICAL MODEL IN PSPICE
In practice, fuel cells normally work together with other electrical
devices, such as power-electronic converters. PSPICE is a
valuable simulation tool used to model and investigate the behavior
of electrical devices and circuits. An electrical equivalent
model of fuel cell, built in PSPICE, can be used with electrical
models of other components to study the performance characteristics
of the fuel-cell power generation unit. A block diagram
to build such a model is given in Fig. 4, which is based on the
characteristics discussed in Section III. The development of an
electrical circuit model for different blocks in Fig. 4 is discussed
below.
CONCLUSION
This paper presents the dynamic model development for PEM
fuel cells in MATLAB/SIMULINK and PSPICE environments.
The electrical circuit elements and their properties are used in
the modeling. Both the double-layer charging effect and the
thermodynamic property of the fuel cell are taken into account
in these models. Validation of the models has been carried out
through experiments on a 500-W Avista Labs SR-12 PEM fuelcell
stack. Simulation results show that the models can predict
the electrical response of the PEM fuel-cell stack under
steady-state as well as transient conditions. The models can also
predict the temperature response of the fuel-cell stack and show
the potential to be useful in external controller design applications
for PEM fuel cells.
[attachment=46471]
Abstract—
This paper presents the development of dynamic
models for proton exchange membrane (PEM) fuel cells
using electrical circuits. The models have been implemented
in MATLAB/SIMULINK and PSPICE environments. Both the
double-layer charging effect and the thermodynamic characteristic
inside the fuel cell are included in the models. The model
responses obtained at steady-state and transient conditions are
validated by experimental data measured from an Avista Labs
SR-12 500-W PEM fuel-cell stack. The models could be used in
PEM fuel-cell control related studies.
INTRODUCTION
PROTON EXCHANGE MEMBRANE (PEM) fuel cells
show great promise for use as distributed generation (DG)
sources. Compared with other DG technologies, such as wind
and photovoltaic (PV) generation, PEM fuel cells have the
advantage that they can be placed at any site in a distribution
system, without geographic limitations, to achieve the best
performance. Electric vehicles are another major application
of PEM fuel cells. The increased desire for vehicles with less
emission has made PEM fuel cells attractive for vehicular
applications since they emit essentially no pollutants and have
high-power density and quick start.
PEM fuel cells are good energy sources to provide reliable
power at steady state, but they cannot respond to electrical load
transients as fast as desired. This is mainly due to their slow
internal electrochemical and thermodynamic responses. The
transient properties of PEM fuel cells need to be studied and analyzed
under different situations, such as electrical faults on the
fuel-cell terminals, motor starting, and electric vehicle starting
and acceleration.
DYNAMIC MODEL BUILT IN MATLAB/SIMULINK
A dynamic model for the PEM fuel cell has been developed
in MATLAB/SIMULINK, based on the electrochemical and
thermodynamic characteristics of the fuel cell discussed in
Section III. The fuel-cell output voltage, which is a function
of temperature and load current, can be obtained from the
model. Fig. 3 shows the block diagram, based on which the
MATLAB/SIMULINK model has been developed. In this
figure, the input quantities are anode and cathode pressures,
initial temperature of the fuel cell, and room temperature. At
any given load current and time, the internal temperature is
determined and both the load current and temperature are fed
back to different blocks, which take part in the calculation of
the fuel-cell output voltage.
EQUIVALENT ELECTRICAL MODEL IN PSPICE
In practice, fuel cells normally work together with other electrical
devices, such as power-electronic converters. PSPICE is a
valuable simulation tool used to model and investigate the behavior
of electrical devices and circuits. An electrical equivalent
model of fuel cell, built in PSPICE, can be used with electrical
models of other components to study the performance characteristics
of the fuel-cell power generation unit. A block diagram
to build such a model is given in Fig. 4, which is based on the
characteristics discussed in Section III. The development of an
electrical circuit model for different blocks in Fig. 4 is discussed
below.
CONCLUSION
This paper presents the dynamic model development for PEM
fuel cells in MATLAB/SIMULINK and PSPICE environments.
The electrical circuit elements and their properties are used in
the modeling. Both the double-layer charging effect and the
thermodynamic property of the fuel cell are taken into account
in these models. Validation of the models has been carried out
through experiments on a 500-W Avista Labs SR-12 PEM fuelcell
stack. Simulation results show that the models can predict
the electrical response of the PEM fuel-cell stack under
steady-state as well as transient conditions. The models can also
predict the temperature response of the fuel-cell stack and show
the potential to be useful in external controller design applications
for PEM fuel cells.