
Heinzinger electronic GmbH
Phone: +49 (0) 8031 2458 0
www.heinzinger.com
Anton-Jakob-Str. 4, 83026 Rosenheim
Fax: + 49 (0) 8031 2458 58
Germany
Page 93
ERS COMPACT
3.11.13
Simple PV (photovoltaics) function
3.11.13.1
Preface
This function runs exclusively in source mode (PS) and
uses the integrated XY generator to have the power supply
simulate solar panels or cells with certain characteristics
by calculating an IU table from four typical parameters.
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, defined by
U
MPP
and I
MPP
The voltage of the MPP (here: U
MPP
) lies typically 20% below U
OC
, the current of the MPP (here: I
MPP
) lies typically
10% below I
SC
. In case there are no definite values for the simulated solar cell available,
Impp
and
Umpp
can be
set to these typical values. The device limits the I
MPP
value to I
SC
as upper limit, the same applies to U
MPP
and U
OC
.
3.11.13.2
Safety notices
Due to high capacitance on the DC terminal of some models, 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.
3.11.13.3
Usage
In the PV function, which is based upon the XY generator and an IU table, the MPP (maximum power point) is de
-
fined 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 of the MPP
Impp
0 A...Isc
DC output current of 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 Gen
-
erator 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 val
-
ues (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.