© EA Elektro-Automatik in 2022, this information is subject to change without notice
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06230820_manual_psi_10000_3u_15kw_en_01
3.10.13
Simple PV (photovoltaics) function
3.10.13.1 Preface
This function uses the standard XY generator to let the power
supply simulate solar panels or solar cells with certain char-
acteristics. The device calculates an IU table from four typical
values.
While the function is running, the user can adjust a 5
th
parameter
called
Irradiance
to simulate different light situations.
The most important characteristics of a solar cell are:
• the short-circuit current (I
SC
), the maximum current at almost
0 V
• the open circuit voltage (U
OC
), which almost reaches its
maximum value even in low light situations
• the maximum power point (MPP), at which the solar panel can provide the maximum output power
The voltage of the MPP (here: U
MPP
) lies typically 20% below U
OC
, the current of the MPP (here: I
MPP
) lies typically 5% below
I
SC
. In case there are no definite values for the simulated solar cell available, Impp and Umpp can be set to this rule of thumb.
The device limits the I
MPP
value to I
SC
as upper limit, the same applies to U
MPP
and U
OC
.
3.10.13.2 Safety notices
Due to high capacities on the DC outputs of the power supplies of this series, not every available solar
inverter can be operated without problems. Check the technical specifications of the solar inverter and
probably contact the inverter’s manufacturer for an evaluation.
3.10.13.3 Usage
In the PV function, which is based upon the XY generator and an IU table, the MPP (maximum power point) is defined by the
two adjustable parameters
Umpp
and
Impp
(also see diagram below). These parameters are usually stated in data sheets of
solar panels and have to be entered here.
The following parameters can be set for the PV function:
Parameter
Range
Description
Uoc
Umpp
...rated device voltage
Open circuit voltage at no load
Isc
Impp
...rated device current
Short-circuit current at max. load and low voltage
Umpp
0 V...Uoc
DC output voltage at the MPP
Impp
0 A...Isc
DC output current at the MPP
Schematic diagram:
Application and result:
U
I
I
SC
U
OC
MPP
I
M
PP
U
MPP
Adjust all four parameters on screen to the desired values. Whether the
calculated IU and P curves which result from those values make sense
or not can be verified with tools which can visualize the curve data,
such as EA Power Control (only with unlocked Function Generator app)
where you could enter the same values and have the curve visualized
upon button click.
While the simulation is running, the user can see from the actual values
(voltage, current, power) of the DC output, where the operating point of
the power supply resp. of the simulated solar panel is. The adjustable
value
Irradiance
(0%...100% in 1% steps, see screenshot below) helps
to simulate different light situations from darkness (no power output)
to the minimal amount of light that is required to have the panel provide
full power.
