Delta Solivia 2.5, Operation And Installation Manual

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4.2 Technical structure of the solar inverter
A galvanical isolation of the solar inverter from the grid is achieved through a DC/AC converter with
an integrated high-frequency transformer. The photovoltaic voltage is adjusted so that the maximum
power output of the PV modules is also achieved with varying solar irradiation levels and tempera-
tures (MPP-Tracking).
The MPP range of the solar inverter is between 150 V and 450 V. This facilitates the use of PV
modules by a variety of manufacturers. Measures must be taken to ensure that the maximum open-
circuit voltage of 540 VDC is never exceeded. Please note that the maximum open-circuit voltage
will occur at the lowest temperatures anticipated. You will find more detailed information about
temperature dependency in the data sheet of the PV modules. The device’s power consumption is
kept to a minimum.
The high-quality aluminum casing corresponds to protection class IP65 (water-jet-proof and dust-
proof) and is protected against weathering processes by surface refinement. The cooling charac-
teristic profile is designed so that operation of the inverter is possible with ambient temperatures
from -25°C to +70°C.
A cooling characteristic profile is used for the removal of the power dissipation caused through the
voltage conversion. An internal temperature control protects the device against excessive tem-
peratures in the interior of the solar inverter. In case of high ambient temperatures, the maximum
transferable power is limited.
The solar inverter is controlled by microcontrollers, which also implement interface communication
and the monitoring of values and messages on the display.
Two independent and redundant microcontrollers control the monitoring of the grid, which is con-
sistent with the feed-in directives of your local utility company and DIN VDE 0126-1-1, EN 50438,
ENEL G.L. 12/2008 and RD 1663 (anti-islanding protection). This enables an installation of the solar
inverter in the in-house electrical grid.
Operator protection requirements are met by electrically isolating the grid from the PV module. The
electrical isolation between the grid and the PV module is equivalent to basic insulation. Maximum
operator protection is ensured by reinforced isolation between the grid, PV modules and accessible
interfaces (display and RS485 interface). Relevant standards concerning electromagnetic compat-
ibility (EMC) and safety are fulfilled.
The solar inverter is functional in on-grid operation exclusively. An automated isolation point, which
is approved by a certification agency, guarantees secure disconnection in case of circuit isolation or
interruptions in power supply and avoids isolated operation.
The disconnection equipment allows for automatic isolation for in-plant generation systems of nomi-
nal power ≤ 4.6 kVA, with single-phase parallel feed-in through the solar inverter into the public grid.