Studer Innotec SA
VarioString
18
User manual
36 cell
module
Voc < 25V
60 cell
module
Voc < 42V
72 cell
module
Voc < 50V
Thin film
module
Voc < 110V
max.
max.
max.
--
21
12
10
4
For
VS-70
or
VS-120
with
independent or parallel inputs
32
19
16
7
For VS-120 with two inputs in series
Beware of the PV module temperature! The above values are for modules under standard test
condition (STC).
4.3.3
Parallel connection of PV module strings
To get the required charging power, 2 or more strings can be connected in parallel. Each string
connected in parallel shall be composed of the same number of modules of the same type.
When using the two entries on the VarioString VS-120 in parallel (up to 26A) it is necessary to physically
connect the two negative terminals (3) and (5) as well as the two positive terminals (4) and (6).
The two inputs can only be put in parallel when there is no voltage present. The four inputs
(3), (4), (5) and (6) should be disconnected at least 10 minutes before connecting the "Y"
cable in parallel.
1.
Disconnect all PV sources and wait 10 minutes.
2.
First connect the inputs (3) and (5), and (4) and (6) with the "Y" parallel cable.
3.
Only at this point, the PV generators may be connected to the "Y" cables.
The number of strings connected in parallel depends on the power of each module. The sum of the
power of all the panels connected to a VarioString should not exceed the power that the VarioString
can charge.
The recommended number of strings to be connected in parallel is equal to 3500W divided by the
power of a string and rounded down to the nearest whole number. (see table below)
For example, with 12 modules of 110W in series: 3500/1320=2.65 => 2 strings (2640W) can be
connected in parallel.
If both VarioString inputs are connected in parallel, for the
strings of 12 modules in series mentioned above, 5 strings
could be connected in parallel (7000/1320=5.3 =>5).
The PV generator can be over-dimensioned in order to get
the required charging power even when solar irradiation is
lower. In this case, a part of the solar energy will be lost
when the solar irradiation is higher because the VarioString
will reach its current limit and curtail power output. By looking at the example above, 3 strings could
be used however the maximum power of 3960W will not be reached as the VarioString will limit the
power to a maximum value of 3500W.
4.3.3.1
Maximum current of the solar generator
The maximum current of the solar generator is limited to 13 A for the VS-70 and the VS-120 when
connected in series or independently (13A per input) or to 26A for the VS-120 when connected in
parallel.
Maximum recommended power
for the solar generator
VS-120
Battery
MPPT input 1
3500W
48V
MPPT input 2
3500W
48V
Total
7000W
48V
The VarioString has a current limit. At any given time, the maximum power of the VarioString
depends on the charging phase voltage of the battery. For example, if the charging phase
is Bulk, and the battery voltage is 50V, the maximum power output for the VS-120 is 120A *
50V = 6000W and for the VS-70 70A*50V = 3500W. Even if more solar energy is available, the
battery charge current will not exceed 120A (VS-120) and 70A (VS-70).
Содержание VarioString VS-120
Страница 2: ...Studer Innotec SA VarioString 2 V 2 3 User manual ...
Страница 13: ...Studer Innotec SA VarioString User manual V 2 3 13 4 1 2 VarioString VS 120 ...
Страница 61: ...Studer Innotec SA VarioString User manual V 2 3 61 ...
Страница 62: ...Studer Innotec SA VarioString 62 V 2 3 User manual ...
Страница 63: ...Studer Innotec SA VarioString User manual V 2 3 63 ...
