SMA Solar Technology AG
7 Grid Monitoring
User Manual
SCCP-JP-BA-A4-en-12
45
7 Grid Monitoring
7.1 How Grid Monitoring Works
The Sunny Central monitors the utility grid to make sure it stays within configurable thresholds. If the grid values exceed
or fall below these thresholds for a set time, the Sunny Central will disconnect from the utility grid for safety reasons.
The following thresholds are monitored:
• Voltage drop
• Voltage increase
• Frequency drop
• Frequency increase
For each threshold, you can set a tripping delay time stipulating how long the grid error must be pending before the
Sunny Central disconnects from the utility grid.
7.2 Setting Line Voltage Monitoring
You can specify the thresholds and tripping time manually. For voltage monitoring, you can set two limits for overvoltage
and two limits for undervoltage.
If the line voltage rises above the value defined in the parameters
VCtlhhLim
or
VCtlhLim
, the Sunny Central waits for
the period defined in the parameters
VCtlhhLimTm
or
VCtlhLimTm
and disconnects from the utility grid.
Figure 16: Temporal Sunny Central behavior when the grid limits are exceeded
Position
Parameters Description
A
VCtlhhLimTm Delay time for grid limit level 2
B
VCtlhLimTm
Delay time for grid limit level 1
C
‒
Startup/MPP load operation
D
‒
Grid monitoring
E
‒
Disturbance
1
VCtlhhLim
Line voltage limit level 2
