7 Commissioning
SMA Solar Technology AG
Operating manual
SI44M-80H-13-BE-en-15
90
7.7.5
Setting Time-Dependent Two-Level Load Shedding
The basic procedure for changing operating parameters is explained in another section (see Section 8.6, page 113).
The time-dependent load shedding divides the day into 2 intervals (see Section 8.12.2, page 117). You set the SOC
thresholds that apply for each interval for 2-stage load shedding. For example, you can set that as far as possible no
loads are to be disconnected from the utility grid during the day.
Significance of the SOC thresholds:
Two lower and two upper SOC thresholds are available for each interval for controlling the load-shedding contactors.
The load-shedding contactors disconnect the loads from the utility grid if the states of charge are as follows:
• When the state of charge of the battery reaches the first lower SOC threshold, the multifunction relay opens the
connected load-shedding contactor for the first level of load shedding. The load-shedding contactor disconnects
those loads from the utility grid that are to be disconnected for the first level.
• When the state of charge of the battery reaches the second lower SOC threshold, the multifunction relay opens
the connected load-shedding contactor for the second level of load shedding. The load-shedding contactor
disconnects the remaining loads from the utility grid.
• When the state of charge of the battery reaches the second upper SOC threshold during recharging, the
multifunction relay closes the connected load-shedding contactor for the second level of load shedding. The load-
shedding contactor connects those loads to the utility grid that were disconnected for the second level.
• When the state of charge of the battery reaches the first upper SOC threshold during recharging, the multifunction
relay closes the connected load-shedding contactor for the first level of load shedding. The load-shedding
contactor connects those loads, which were disconnected for the first level, to the utility grid. All loads are
connected to the utility grid.
Procedure:
• Set the start time for the standard time period and the additional time period.
• Set the SOC threshold for the standard time period.
• Set the SOC threshold for the additional time period.
Set the start time for the standard time period and the additional time period
1. Select
Device > Load shedding 1 > Additional time range
.
2. Set the parameter
Time load shedding 1
to the start time for the first interval.
3. Set the parameter
Start time additional time range load shedding 1
to the start time for the second interval.
Set the SOC threshold for the standard time period
1. Select
Device > Load shedding 1
.
2. Set the parameter
Lmt value battery state of charge for start load shedding 1
to the lower SOC threshold
for the first stage of load shedding.
3. Set the parameter
Lmt value battery state of charge for stop load shedding 1
to the upper SOC threshold
for the first stage of load shedding.
4. Select
Device > Load shedding 2
.
5. Set the parameter
Lmt value battery state of charge for start load shedding 2
to the lower SOC threshold
for the second stage of load shedding.
6. Set the parameter
Limit battery state of charge for stop load shedding 2 in add time range
to the upper
SOC threshold for the second stage of load shedding.
