Setting Utilization Of Excess Energy In Off-Grid Systems - SMA SUNNY ISLAND 3.0M Installation Manual

SMA Solar Technology AG
6. Ensure that the multifunction relay used for controlling the first level of load shedding is set to AutoLod1Soc
(see Section 8.1.5 "Setting the Functions of the Multifunction Relays", page 71).
7. Ensure that the multifunction relay used for controlling the second level of load shedding is set to AutoLod2Soc.
8.3.6

Setting Utilization of Excess Energy in Off-Grid Systems

Figure 26: Switching-on time and switching-off time for utilization of excess energy during constant voltage phase
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 241.07 ExtPwrDerMinTm. If the cell voltage differs by
more than 241.08 ExtPwrDerDltVtg from the setpoint of the cell voltage, the multifunction relay is deactivated. The
setpoint of the cell voltage depends on the charging process during the constant voltage phase.
Charging process
Boost charge
Full charge
Equalization charge
To control the utilization of excess energy, set the multifunction relay on the Sunny Remote Control as follows: It is not
possible to set the multifunction relay on the communication product for utilization of excess energy.
Procedure:
1. Switch to expert mode on the Sunny Remote Control (see the Sunny Island operating manual).
2. Select the parameter 241.07 ExtPwrDerMinTm and set it to the minimum time that the multifunction relay remains
activated.
3. Select the parameter 241.08 ExtPwrDerDltVtg and set it to the voltage difference relative to the setpoint of the
cell voltage during the constant voltage phase.
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 ExtPwrDer (see Section 8.1.5 "Setting the Functions of
the Multifunction Relays", page 71).
Installation manual
Parameter
Cell charge setpoint voltage for boost charge / 222.07 ChrgVtgBoost 2.40 V
Cell charge setpoint voltage for full charge / 222.08 ChrgVtgFul
Cell charge target voltage for equalization charge /
222.09 ChrgVtgEqu
SI30M-44M-60H-80H-IA-en-32
8 Commissioning
Default value
2.45 V
2.45 V
89