Solver Settings

Solver settings control the behavior of the RAMSES simulation engine. They are specified as records starting with $ in the data files.

Sampling and Output

Plot Step

Sampling time for observed variables:

$PLOT_STEP time(s) ;

Display Profiling

Display profiling results after simulation:

$DISP_PROF T/F ;

Run-Time Refresh Rate

Refresh interval for runtime observable plots (requires Gnuplot):

$GP_REFRESH_RATE time_interval(s) ;

System Parameters

Base Power

Sets the global base power of the system:

$S_BASE BASE(MVA) ;

Nominal Frequency

FNOM Frequency(Hz) ;

Reference Frame

$OMEGA_REF SYN/COI ;

SYN — Synchronous reference frame (suitable for short-term simulations)
COI — Center of inertia reference (suitable for long-term simulations)

See Reference Frames for details.

Numerical Parameters

Newton Tolerance

$NEWTON_TOLER NETWORK_TOLERANCE INJ_RELATIVE_TOLERANCE INJ_ABSOLUTE_TOLERANCE ;

Default values: 1e-03, 5e-04, 5e-04.

Finite Difference Values

Values used to compute Jacobian matrices of injectors numerically:

$FIN_DIFFER proportional_value absolute_value ;

Full Jacobian Update

Disable partial Jacobian updates (force full update at every step):

$FULL_UPDATE T/F ;

Skip Converged Blocks

Activate/deactivate skipping of converged injectors in Newton iterations:

$SKIP_CONV T/F ;

Maximum Fault Value

$MAX_FAULT value ;

Advanced Solver Options

Solution Scheme

$SCHEME DE/IN ;

DE — Decomposed scheme
IN — Integrated scheme

Latency Settings

$LATENCY OBS_TIME_WINDOW(s) EARLY_STOP(T/F) ;

Load Restoration Time Constant

$T_LOAD_REST time(s) ;

Network Frequency Update

Update network elements (admittances) with frequency:

$NET_FREQ_UPD T/F ;

Parallel Computing

Number of Threads

$NB_THREADS Number ;

Thread Distribution Strategy

$OMP STA/DYN/GUI chunk ;

Option	Description
`STA`	Static assignment (better for NUMA architectures)
`DYN`	Dynamic assignment (better for UMA architectures)
`GUI`	Guided assignment

chunk is the number of consecutive injectors assigned to each thread.

Typical Configuration

# System base
$S_BASE 100. ;
FNOM 50. ;

# Reference frame (COI for long-term)
$OMEGA_REF COI ;

# Solution scheme
$SCHEME IN ;

# Solver tolerances
$NEWTON_TOLER 1e-03 5e-04 5e-04 ;

# Plotting
$PLOT_STEP 0.01 ;

# Parallel computing
$NB_THREADS 2 ;
$OMP DYN 50 ;

# Acceleration features
$SKIP_CONV T ;
$FULL_UPDATE F ;