SMA CLUSTER CONTROLLER - Manual (Page 66)

13 Grid Management Services
13.1 Options for Implementing Grid Management Service
Setpoints
You can have the Cluster Controller implement the grid management service setpoints by using
open-loop or closed-loop control.
In the event that the Cluster Controller evaluates a setpoint as invalid or does not receive a setpoint
within a configurable interval, you can make additional settings for the fallback (see Section 13.5,
page 74).
The setpoint for active power limitation is specified in percent. The total system power is taken as
the reference value. By default, the system inverter power determined by the Cluster Controller is set
as the value for the total system power. If necessary, you can adjust the value when configuring the
active power limitation.
Open-loop control
For Cluster Controller systems without self-consumption and with direct limitation of active power
feed-in, the operating mode Open-loop control is used. In this operating mode, the
Cluster Controller can receive the grid management service setpoints from three different types of
signal source. The different signal sources can be combined:
Type of setpoint signal Explanation
Digital signals The setpoints are transmitted to the Cluster Controller as
digital signals in the form of binary values. Up to four re-
lay contacts can be used for the active power limitation
and the reactive power setpoint.
Analog signals The setpoints are transmitted to the Cluster Controller as
analog current signals. Current signals from 0 mA to
20 mA can be transmitted for the active power limitation
and the reactive power setpoint.
Setpoint signal via Modbus client The setpoints are transmitted via a Modbus client to the
network port X13 or X14 on the Cluster Controller (for in-
formation on Modbus configuration, see Section 12,
page 64).
Closed-loop control
For Cluster Controller systems with self-consumption, the operating mode Closed-loop control is
used. In this operating mode, you can regulate the active power fed in by the system at the grid-
connection point and limit it e.g. to a fixed percentage value. In addition to the total system power,
the Cluster Controller needs the measured actual value of the active power fed in at the grid-
connection point.
13 Grid Management Services SMA Solar Technology AG / SMA America, LLC
User Manual ClusterController-BA-en-14 66