Steca StecaGrid 2010+ Master, Инструкция по установке и эксплуатации

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3 Technical structure of the StecaGrid
3.1 General
The StecaGrid is an inverter that uses a transformer to galvanically isolate solar mod-
ules from the mains grid, etc. The inverter was designed so that it can be installed
outside without any problems (IP65).
The StecaGrid is controlled by microcontrollers. The microcontrollers set the voltage
of the solar modules in such a way that the solar modules provide their maximum
output (maximum power point tracking). Both inputs have their own MPP tracker
which allows you to design your system flexibly. For example, you can connect the
modules with a south-east orientation to Input 1 and the modules with a south-
west orientation to Input without any mismatches and therefore any loss in yield.
Furthermore, it is possible to connect type-A modules to Input 1 and type-B modules
to Input without any mismatch occurring.
The input voltage range was selected in such a way that the rated voltage range of
the PV modules is covered from 80 V - 410 V (open circuit voltage max. 450 V). The
maximum input current that the inverter can process is 8 A per input. When both
inverter inputs are connected in parallel the inverter can process currents up to 16 A.
The MPP tracker ensures that the input currents never exceed the maximum permit-
ted current.
The negative inputs of the StecaGrid 010+ are connected with a 100-kOhm
resistance to the PE potential and therefore have functional earthing. This enables
the StecaGrid 010+ to operate amorphous and micromorphous thin-film modules
without additional external earthing. Although the resistance between the negative
inputs and the PE also enables the positive inputs to be externally earthed, a secure
connection from the PV to the PE cannot be guaranteed in this case. Furthermore, a
slight reduction in yield is to be expected.
At night, the inverter keeps its use of the electronic components and electricity
consumption to a minimum by switching to sleep mode. The inverter is protected
against stand-alone operation.
3.2 Master-slave principle
The StecaGrid works according to the master-slave principle. With this principle,
several functions are combined in the master (inverter A in the diagram).
The inverters without these functions are referred to as slave inverters (inverters B
and C in the diagram). The regional settings are made via the master.
An MSD function is regulated for all the inverters via the master. The master also
stores data from the master inverter and the slave inverters, etc. Because the func-
tions are combined centrally, slave inverters can be realised more cost-effective and
more compact. StecaGrid Slave inverters can be connected to each StecaGrid Mas-
ter inverter. Any type of StecaGrid Master inverter can be combined with any type
of StecaGrid Slave inverter (a maximum of two slaves per master is possible). The
combination of master and slave devices allows the dimensioning to be as flexible as
possible: System sizes between 1600 Wp and 7000 Wp are possible using master-
slave combinations.* For system sizes greater than 7000 Wp several master-slave
combinations can be used.
* with a sizing ratio between 0.8 and 1.5 and assuming that the system voltage and system current are within the operating
range of the inverter.
See www.stecasolar.com for a dimensioning software.
3.3 Cooling
The inverter transfers its heat via a cooling element. Because of the large surface
area of the cooling profile the inverter can operate in ambient temperatures be-
tween –5 °C and +60 °C.
WARNING
Risk from hotness!
The surface temperature of the aluminium cover may exceed 70 °C.
An integrated temperature control prevents excessive internal temperatures. When
the ambient temperature exceeds the (derating) limit, the highest value of the
power consumption from the PV modules is automatically adjusted to the prevailing
temperatures. This process reduces the heat transfer from the inverter and prevents
the operating temperature from becoming too high. When the ambient tempera-
ture is above +40 °C, maximum output can be restricted. StecaGrid inverters do
without a ventilator for cooling and are therefore particularly low-maintenance.

X A B C
Master
X) Control unit
A) Inverter A
B) Inverter B
C) Inverter C
Slave Slave