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Prioritization between different control modes (with Hybrid EMS)
The blue'Log XC can receive control commands from different sources (e.g. grid operator and energy trader) but can also locally generate its own setpoints in case of frequency events where the functions LFSM-U, LFSM-O, or FSM are active. The priority in this context and in case of temporary overlap is described below.
Prioritization between grid operator and energy trader
The grid operator can send setpoints via the following blue'Log interfaces: Modbus power control, digital input, or analog input.
The energy trader can use the Remote Power Control interface to send setpoints.
If the setpoints of the grid operator and energy trader overlap, the lower value always has priority.
Prioritization between grid operator and energy trader
Prioritization between grid operator, energy trader, and frequency control
Only one of the three frequency control modes—LFSM-U, LFSM-O, or FSM—can operate at a time. LFSM-U and LFSM-O have priority over FSM. The following describes the priority between the grid operator’s setpoint, the energy trader’s setpoint, and frequency control.
Prioritization when LFSM-U/LFSM-O is active
When LFSM-U or LFSM-O is active, the energy trader’s setpoint is always ignored. The prioritization between LFSM-U/LFSM-O and the grid operator’s setpoint depends on a setting called Prioritizing grid operator setpoint. This setting can be activated in the following menu:
Frequency-dependent control - Configuration “Prioritizing grid operator setpoint”
Grid operator setpoint prioritized
If the function Prioritizing grid operator setpoint is activated, the lower value between the grid operator setpoint and the frequency control setpoint applies.
Grid operator setpoint prioritized
Grid operator setpoint not prioritized
If the function Prioritizing grid operator setpoint is deactivated, the setpoint of the grid operator is always ignored and only the frequency control setpoint applies.
Grid operator setpoint not prioritized
Prioritization when FSM is active
When FSM is active, the prioritization between the grid operator’s setpoint, the energy trader’s setpoint, and FSM depends on the configured Base value. The Base value is a parameter that can be selected in the options of the FSM menu (prerequisite: RPC license is installed). For more information, see Frequency control modes (with Hybrid EMS).
Base value equals the RPC setpoint
If the Base value is selected as remote power control setpoint PRPC the prioritization is as follows, whereby ΔPFSM is the active power change resulting from the P(f) characteristic curve:
Pbase = PRPC
Base value equals the current setpoint
If the Base value is selected as the momentary active power Pmom the prioritization is as follows. PFSM is the setpoint generated by the FSM function:
Pbase = Pmom