7 Commissioning
SMA Solar Technology AG
Operating manual
SI44M-80H-13-BE-en-15
92
The Sunny Island controls the utilization of excess energy during the constant voltage phase depending on the cell
voltage of the battery. During the constant voltage phase, the battery is charged with a constant charging voltage.
When the setpoint of the cell voltage in the constant voltage phase is reached, the multifunction relay is activated. The
multifunction relay remains in this position for the minimum time specified (
Minimum time for the use of excess
energy
). If the cell voltage differs by more than a specified value (
Voltage difference for the use of excess
energy
) from the setpoint of the cell voltage after the minimum time, the multifunction relay is deactivated. The setpoint
of the cell voltage depends on the charging process during the constant voltage phase.
Charging Process
Parameters
Default value
Boost charge
Battery > Charge > Cell charge nominal voltage for boost
charge
2.40 V
Full charge
Battery > Charge > Cell charge nominal voltage for full charg-
ing
2.45 V
Equalization charge
Battery > Charge > Cell charge nominal voltage for equaliza-
tion charge
2.45 V
The basic procedure for changing operating parameters is explained in another section (see Section 8.6, page 113).
Procedure:
1. Set the parameter
Minimum time for the use of excess energy
to the minimum time that the multifunction relay
remains activated.
2. Set the parameter
Voltage difference for the use of excess energy
to the voltage difference relative to the
setpoint of the cell voltage during the constant voltage phase.
3.
Recording of the measured values of the cell voltage reacts to changes with time-lag
The Sunny Island calculates the cell voltage from the measured battery voltage. The Sunny Island calculates
an average from the measured values of the battery voltage. As a result of the calculation of an average, the
cell voltage that is recorded reacts to changes with a time-lag.
4. Ensure that the multifunction relay used for control is set to
Control of add. loads
7.8
Generator Management
7.8.1
Configuration of the Thresholds for Generator Connection
7.8.1.1
Changing the Current Thresholds for the Generator
Relevant for off-grid systems
The basic procedure for changing operating parameters is explained in another section (see Section 8.6, page 113).
Significance of the current limits:
The generator management limits the consumption of generator current to the maximum set value.
In three-phase systems, the generator current is limited for each line conductor individually. The set value applies to
each line conductor.
For Sunny Island inverters that are operated in parallel, the generator management only limits the total generator
current. The generator current may be unequally distributed to the Sunny Island inverters. If a Sunny Island fails, for
example, more current flows through the remaining Sunny Island inverters.
Enhanced generator management:
If the set generator current is not sufficient for supplying the loads, the generator management requests additional
current from the battery. The system then supplies the loads with the generator current and the battery current.
