The objective is to limit the active power setpoint of a generation unit depending on the voltage measurement at a terminal. For this functionality, a two slightly different QDSL-Models that can be used for this, are attached to this ticket with the following behaviour:

The models limit the infeed of the generation unit based on the voltage at its terminals. As several generation units can affect the same voltage, this is carried out in several iteration steps to avoid oscillating behaviour that alternates between limitation and non-limitation.

Input Parameters

The slope of the power limiting curve is defined with the input values ured and ulim. The power limitation starts when the voltage is above ured and the infeed is reduced to zero when ulim is exceeded.

loopmax: Maximal number of Load Flow Control Loops that will be executed before the Control Loop is set as finished

step_init: Initial maximum step (in p.u.) that can be done between two calls of the Load Flow Control. The maximum step size is reduced by 1/3 in each call of the Load Flow control to avoid oscillating behaviour.

accuracy: If the change (in p.u.) between two Load Flow Control calls is smaller the accuracy, the Control loop is set as finished.

Difference between the two models

QDSL P-V with c_Pmax

This model sets the parameter c:Pmax of the generation unit in the Load Flow Control to set a limit for the permissible active power infeed.

QDSL P-V with pset

This model directly sets the the power infeed of the generation unit with the signal pset in the Load Flow Equations.