Communication-loss fallback

Communication-loss fallback puts inverters into a defined feed-in state when control communication fails or setpoints stop arriving. After an adjustable timeout, the inverter either keeps the last values it received or applies preset fallback values. The SMA Cluster Controller supports two fallback types, and each is configured separately. One covers a missing or invalid external setpoint. The other covers failure of Speedwire communication between the controller and the inverters. The Speedwire fallback cannot be configured on inverters with a Speedwire Webconnect Piggy-Back. It is designed for inverters with the Speedwire/Webconnect data module and for Sunny Boy Smart Energy. Inverters controlled by the SMA Inverter Manager switch to their fallback state when communication is interrupted, and they report status events 2055 and 2056. Fallback is set up through the grid code file or the LCS-Tool. The system-level fallback toward a SCADA or power plant controller needs the LCS-Tool and a Grid Guard code. On the Sunny Tripower CORE2 you set a waiting time of at least 20 seconds and a fallback value. A fallback value of 0 percent still lets about 1 to 2 kW feed in, and fallback cannot be set to disconnect from the grid. SMA states that the activation and configuration of fallback must be agreed with the grid operator.