User Manual

Page 75
EA Elektro-Automatik GmbH
Helmholtzstr. 31-37 • 41747 Viersen
Germany
Fon: +49 2162 / 3785-0
Fax: +49 2162 / 16230
www.elektroautomatik.de
[e-mail]
PSB 9000 2.5 kW Series
3.11.14 FC table function (fuel cell)
3.11.14.1 Preface
The FC table function is used to simulate the characteristics of voltage and
current of a fuel cell. This is achieved by setting up some parameters which
denepointsonatypicalfuelcellcurve,whichisthencalculatedasUItable
and passed to the internal function generator.
The user has to adjust value for four support points. The device will request
to enter them step by step, indicating the actual point on screen with small
graphics.Whennished,thesepointswillbeusedtocalculatethecurve.
Generally, following rules apply when setting up those values:
• U
Point1
> U
Point2
> U
Point3
> U
Point4
• I
Point4
> I
Point3
> I
Point2
> I
Point1
• Values of zero are not accepted
It means, the voltage has to decrease from point 1 to point 4, while the current
has to increase. In case the rules are not followed, the device will reject the
values with an error and reset them to 0.
3.11.14.2 Usage
The following parameters can be set for the FC table function:
Value Range Description
Point 1: Uoc 0 V...U
Nom
Maximum voltage of the cell (open circuit voltage at no load)
Points 2+3: U 0 V...U
Nom
VoltageandcurrentdenethepositionofthesetwopointsintheXYcoordinate
system, which represent two supporting points on the curve to be calculated
Points 2+3: I 0 A...I
Nom
Point 4: Isc 0 A...I
Nom
Maximum output current of the fuel cell (short-circuit situation)
U 0 V...U
Nom
Global voltage limit
P Source 0 W...P
Nom
Global power limit, must not be 0 in order for the function to run as expected
All these parameters all freely adjustable and thus an unrealistic curve could result. In some
situations, the device would show a “Calculation error” when tapping the next point to congure.
In this situation, check your settings, adjust and try again.
Schematic diagram: Application and result:
I
U
Uoc
Isc
P2
P3
P1
P4
After setting up the four supporting points Point 1 thru Point 4, whereas
Point1isdenedbyUocand0AandPoint4isdenedbyIscand0V,
the device will calculate the function as XY table and load it to the XY
generator.
Depending on the load current, which can be between 0 A and Isc, the
device will set a variable output voltage, whose progress between 0 V
and Uoc should result in a curve similar to the one depicted to the left.
The slope between Point 2 and Point 3 is depending on the values
adjustedforPoint2andPoint3andcanbefreelymodiedaslongas
Point 3’s voltage is lower than the one of Point 2 and Point 3’s current
is higher than the one of Point 2.
► How to congure the FC table
1. In the function generator menu tap on , then and then .
2. Adjust the parameters of the four supporting points, as required for the simulation.
3. Do not forget to adjust the global limits for voltage and power in the screen which you can access with
touch area .
4. After setting the values for the required signal generation, tap on touch area .
After the function has been calculated and loaded to the internal XY generator, the simulation is ready to start.