SMA SUNNY ISLAND SIC40-MPT, Техническое описание

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SMA Solar Technology AG Battery Management and Charge Control
Technical Description SIC40-TEN081110 35
8 Battery Management and Charge Control
8.1 SMA Operation
If the charge controller is operated in SMA operation and a communication connection has been
established to the Sunny Island 5048/2012/2224, the Sunny Island controls the complete battery
management including the charge control.
The charge controller receives the current and temperature-compensated nominal charging voltage
from the Sunny Island and transmits the battery's present charging current back to the Sunny Island.
This ensures that the battery is always optimally charged and that the Sunny Island calculates the
correct charge state. Further details on the battery management are located in the Sunny Island
documentation.
If the communication does not function in SMA operation, the battery is only securely charged with
13.5/27/54 V.
8.2 Stand-alone Operation
During stand-alone operation or during operation with the Sunny Islands 3324/4248, the charge
controller automatically controls the charging voltage of the battery, depending on the battery type
set and current charging phase, according to the "four-phase charging process" (MPP, boost,
continuous, float). During the first phase, charging is carried out using the maximum power provided
by the PV generator. During the second phase, the charging current is reduced and the battery
voltage is regulated to the charging voltage set for the boost phase. This phase is only completed if
the battery voltage ever drops below 2.08 V/cell during previous discharging. Otherwise, the
charging process is immediately continued with the third phase, continuous. The continuous and the
boost charging phases are identical, except that the continuous phase has a slightly lower charging
voltage. Once the continuous charging is completed, the charge controller switches to float
charging in which it remains until the next discharging.
If a battery temperature sensor is connected, the charging voltage is adjusted to the temperature
using –4 mV/°C and cell.