Disturbances#
Disturbance Devices#
Predefined disturbances at specified time can be created by adding the corresponding devices. Three types of predefined disturbances are supported:
Three-phase-to-ground fault on buses. See Fault for details.
Connectivity status toggling. Disconnecting, connecting, or reconnecting any device, including lines, generators and motors can be implemented by Toggle.
Alteration of values. See Alter for details.
To use these devices, the time of disturbance needs to be known ahead of the simulation. The simulation program by default checks the network connectivity status after any disturbance.
Perturbation File#
One can implement any custom disturbance using a perturbation file as discussed
in [Milano2010]. The perturbation file is a Python script with a function named
pert
. The example for the perturbation file can be found in
andes/cases/ieee14/pert.py
.
- andes.cases.ieee14.pert.pert(t, system)[source]
Perturbation function called at each step.
The function needs to be named
pert
and takes two positional arguments:t
for the simulation time, andsystem
for the system object. Arbitrary logic and calculations can be applied in this function tosystem
.If the perturbation event involves switching, such as disconnecting a line, one will need to set the
system.TDS.custom_event
flag toTrue
to trigger a system connectivity checking, and Jacobian rebuilding and refactorization. To implement, add the following line to the scope where the event is triggered:system.TDS.custom_event = True
In other scopes of the code where events are not triggered, do not add the above line as it may cause significant slow-down.
The perturbation file can be supplied to the CLI using the
--pert
argument or supplied toandes.main.run()
using thepert
keyword.- Parameters
- tfloat
Simulation time.
- systemandes.system.System
System object supplied by the simulator.
- Milano2010
F. Milano, “Power System Modelling and Scripting,” in Power Modelling and Scripting, F. Milano, Ed. Berlin, Heidelberg: Springer, pp. 202-204, 2010.