Elektro-Automatik PSB 9000 3U Series, Руководство по эксплуатации

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Page 85
EA Elektro-Automatik GmbH
Helmholtzstr. 31-37 • 41747 Viersen
Germany
Fon: +49 2162 / 3785-0
Fax: +49 2162 / 16230
www.elektroautomatik.de
ea1974@elektroautomatik.de
PSB 9000 3U Series
3.11.13.1 Mode MPP1
This mode is also called “ find MPP ”. It is the simplest option to have the device find the MPP of a connected solar
panel. It requires to set only three parameters. Value U
OC
is necessary, because it helps to find the MPP quicker
as if the device would start at 0 V or maximum voltage. Actually, it would start at a voltage level slightly above U
OC
.
I
SC
is used as an upper limit for the current, so the device would not try to draw more current than the panel is
specified for. Following parameters can be configured for tracking mode MPP1 :
Value Range Description
U
OC
0...U
Nom
Voltage of the solar panel when unloaded, taken from the panel specs
I
SC
0...I
Nom
Short-circuit current, taken from the panel specs
Δt 5 ms...65535 ms Interval for measuring U and I during the process of finding the MPP
Application and result:
After the three parameters have been set, the function can be
started. As soon as the MPP has been found, the function will stop
and switch off the DC input. The acquired MPP values of voltage
(U
MPP
), current (I
MPP
) and power (P
MPP
) would then be shown in
the display.
The time of a function run depends on the parameter Δt. Even
with the minimum setting of 5 ms one run usually takes already
a few seconds.
3.11.13.2 Mode MPP2
This mode tracks the MPP, so it is closest to the operation
of a real solar inverter. Once the MPP is found, the function
won’t stop, but try to track the MPP permanently. Due to the
nature of solar panels this can only be done below the level
of the MPP. As soon as this point is reached, the voltage
starts to sink further and so does the actual power. The ad-
ditional parameter ΔP defines how much the power may fall
before the direction is reversed and the voltage starts to rise
again until the load reaches the MPP. The result are zigzag
shaped curves of both, voltage and current.
Typical curves are shown in the picture to the right. For the
example the ΔP was set to a quite small value, so the power
curve looks almost linear. With a small ΔP the load would
always track close to the MPP.
Following parameters can be configured for tracking mode
MPP2
:
Value Range Description
U
OC
0...U
Nom
Voltage of the solar panel when unloaded, taken from the panel specs
I
SC
0...I
Nom
Short-circuit current, taken from the panel specs
Δt 5 ms...65535 ms Interval for measuring U and I during the process of finding the MPP
ΔP 0 W...0.5 P
Nom
Tracking/regulation tolerance below the MPP
3.11.13.3 Mode MPP3
Also called “ fast track ”, this mode is very similar to mode MPP2, but without the initial step which is used to find
the actual MPP, because mode MPP3 would directly jump to the power point defined by user input (U
MPP
, P
MPP
).
In case the MPP values of the equipment under test are known, this can save a lot of time in repetitive tests. The
rest of the function run is the same as with MPP2 mode. During and after the function, the least acquired MPP
values of voltage (U
MPP
), current (I
MPP
) and power (P
MPP
) are shown in the display.
Following parameters can be configured for tracking mode
MPP3
:
Value Range Description
U
MPP
0...U
Nom
Voltage in the MPP
I
SC
0...I
Nom
Short-circuit current, taken from the panel specs
P
MPP
0...P
Nom
Power in the MPP
Δt 5 ms...65535 ms Interval for measuring U and I during the process of finding the MPP
ΔP 0 W...0.5 P
Nom
Tracking/regulation tolerance below the MPP