Disturbances

Disturbances define the sequence of events during a dynamic simulation. All disturbance commands follow the format:

time(s) COMMAND parameters

Continue Solver

Defines solver settings. Must be the first line of the disturbance file:

time(s) CONTINUE SOLVER disc_meth max_h(s) min_h(s) latency(pu) upd_over

Discretization method (disc_meth):

• TR — Trapezoidal
• BE — Backward Euler
• BD — BDF2

Jacobian update override (upd_over):

• ALL — Update all injectors and network
• NET — Update only network
• ABL — Update only injectors
• IBL — Update all injectors and network
• NOT — Do not override

Example:

0.000 CONTINUE SOLVER BD 0.0200 0.001 0. ALL

Stop

Signals the end of the simulation. Must be the last line:

time(s) STOP

Example:

100.000 STOP

Trip Line (BREAKER BRANCH)

Open or close breakers of a line:

time(s) BREAKER BRANCH name_of_line orig_break(0/1) extrem_break(0/1)

Example — opening both ends of a line at $t = 10$ s:

10.000 BREAKER BRANCH 1044-4032 0 0

Trip Machine / Injector

Open or close the breaker of a synchronous machine or injector:

time(s) BREAKER SYNC_MACH name_of_machine breaker(0/1)
time(s) BREAKER INJ name_of_injector breaker(0/1)

Example:

10.000 BREAKER INJ L_11 0

Three-Phase Short-Circuit (Impedance)

Apply a three-phase fault with specified impedance to ground:

time(s) FAULT BUS name_of_bus rfault [xfault]
time(s) CLEAR BUS name_of_bus

• rfault and xfault are in Ω
• If xfault is omitted, a fully resistive fault is assumed

Example — 100 ms bolted fault:

10.000 FAULT BUS 1044 0. 0.
10.100 CLEAR BUS 1044

Three-Phase Short-Circuit (Voltage)

Apply a fault where the post-fault voltage is specified:

time(s) VFAULT BUS name_of_bus Voltage_after_fault(pu)
time(s) CLEAR BUS name_of_bus

Example — 100 ms fault with 0.5 pu residual voltage:

10.000 VFAULT BUS 1044 0.5
10.100 CLEAR BUS 1044

Note

Supported from version 3.13 onwards.

Change Parameters (CHGPRM)

Modify model parameters during the simulation.

Branch Parameters

time(s) CHGPRM BRANCH name_of_line MAGN/PHAN ±increment

Shunt Parameters

time(s) CHGPRM SHUNT name_of_shunt QNOM ±increment

The increment is in MVAr.

Exciter Parameters

time(s) CHGPRM EXC name_of_equipment name_of_parameter ±increment [MVAr/%] duration(s)

Units: No unit = absolute, MVAr = per-unitized by $S_{nom}$, % = percentage of original.

Duration: 0 = step change, > 0 = ramp over given duration.

Example — ramp voltage setpoint by +10% over 10 seconds:

10.000 CHGPRM EXC g1 V0 +10 % 10

Torque Controller Parameters

time(s) CHGPRM TOR name_of_equipment name_of_parameter ±increment [MW/%] duration(s)

Example — ramp active power setpoint by +1 MW:

10.000 CHGPRM TOR g1 P0 +1 MW 10

Injector / Two-Port / Discrete Controller Parameters

time(s) CHGPRM INJ/TWOP/DCTL name ±increment [MW/MVAr/%/SETP] duration(s)

Units: SETP = the increment is the new setpoint value.

Example — load increase of 50% active and 30% reactive over 60 seconds:

10.000 CHGPRM INJ L_11 P0 +50 % 60
10.000 CHGPRM INJ L_11 Q0 +30 % 60

Export Jacobian Matrix

time(s) JAC 'name_of_filename'

Required solver settings:

$OMEGA_REF SYN ;
$SCHEME IN ;

Export Load Flow Snapshot

Takes a snapshot and exports the load flow at a specific time:

time(s) LFRESV 'name_of_filename'