Environmental Engineering Reference
In-Depth Information
Table 7.1 Technical specifications of the PEM fuel cell system
PEM fuel cell stack
Number of cells
80 cells
Maximum power
20 kW
Stack voltage range
50-80 V
Stack maximum
current
360 A
Auxiliary components
Air supply compressor
Side channel compressor, max flow rate 95 Nm
3
/h, max pressure
320 mbar, 1.1 kW
Water pump
Centrifugal pump C090, flanged to 24 VDC motor, max pressure
40 kPa, max flow rate 100 l/min
Heat exchanger
Spiral heat exchanger, eight tubes (size 9.53 mm), shell diameter
273.05 9 263.6 mm
Acquisition and control system
d-Space board
Sampling time of 0.01 s
Sensors
Air mass flow meter
Variable area flow meter, 0-60 Nm
3
/h, accuracy 1.6% of full scale
Variable area flow meter, 0-5 Nm
3
/h, accuracy 1.6% of full scale
Water flow meter
Temperature sensors
Resistance thermometer, 0-100 C, accuracy 0.5% of full scale
Pressure transducers
Pressure range 0-500 kPa, accuracy 0.5% of full scale
Humidity transducer
Testo Hygrotest 600/650 humidity temperature; accuracy of up to
±1% RH
Current transducer
Closed loop, Hall effect, accuracy 0.65% @ 300 A
Voltage transducer
Closed loop, Hall effect, accuracy 0.7% @ 100 V
Electric load
Type
IGBT electronic converter connected to electrical resistances
Rated power
20 kW
Input current
0-300 ADC
Input voltage
0-100 VDC
Remote control of
stack current
0-10 VDC
Electrical resistances
4 kW modules
A DC-DC converter of 20 kW based on IGBT technology is interconnected
between the fuel cell system (FCS) and the electric load in order to adapt the
variable stack voltage to the electric load voltage. For the fuel cell dynamic
characterization, the DC-DC converter outlet is first connected to a resistive load,
then to the power train. The resistive load can dissipate electric energy up to a
maximum of 20 kW controlling electronically the discharge current. The DC-DC
converter is equipped with current and voltage sensors to evaluate instantaneously
the electric power flow between the FCS and the electric load or the power train. It
is controlled by the d-space board, which is programmed to follow the desired
stack current reference during the tests.
The test bench for the power train characterization is realized by using a
120 kW dynamic electric brake composed by a three-phase asynchronous machine
