Usage

After Installation, gritulator can be used by creating a continuous-time system model, a discrete-time controller, and a simulation object, as shown below. A 10-kW grid-following converter is used as an example.

from gritulator import model, control
from gritulator import BaseValuesElectrical, plot_grid

# Compute base values based on the nominal voltage, current, frequency and power
base_values = BaseValuesElectrical(
   U_nom=400, I_nom=14.5, f_nom=50.0, P_nom=10e3)

# Create the continous-time system model for a grid coverter
grid_filter = model.LFilter(L_f=0.15*base_values.L, L_g=0, R_g=0)
grid_voltage_source = model.StiffSource(w_N=base_values.w)
converter = model.Inverter(u_dc=650)
mdl = model.ac_grid.StiffSourceAndLFilterModel(
   grid_filter, grid_voltage_source, converter)

# Configure a discrete-time control system.
pars = control.grid_following.GridFollowingCtrlPars(
            L_f=0.15*base_values.L, f_sw = 5e3, T_s = 1/(10e3),
            i_max = 1.5*base_values.i)
ctrl = control.grid_following.GridFollowingCtrl(pars)

# Set the active and reactive power references to change stepwise at t = 0.02 s
# and t = 0.06 s, respectively
ctrl.p_g_ref = lambda t: (t > .02)*1.0*base_values.p
ctrl.q_g_ref = lambda t: (t > .06)*0.5*base_values.p

# Set grid voltage magnitude
mdl.grid_model.e_g_abs = lambda t: base_values.u

# Create the simulation object, simulate, and plot results.
sim = model.Simulation(mdl, ctrl, pwm=False)
sim.simulate(t_stop = .1)
plot_grid(sim, base=base_values)

The Examples folder includes a variety of different example scripts to run the simulation. System and controller configurations can be changed as shown in the examples. Furthermore, new features can be added by modifying the source code.