10-kVA converter, LCL filter

This example simulates a grid-following-controlled converter connected to a strong grid through an LCL filter. The control system includes a phase-locked loop (PLL) to synchronize with the grid, a current reference generator, and a PI-type current controller. The dynamics of the LCL filter are not taken into account in the control system.

from motulator.grid import model, control
from motulator.grid.utils import (
    BaseValues, ACFilterPars, NominalValues, plot)

Compute base values based on the nominal values.

nom = NominalValues(U=400, I=14.5, f=50, P=10e3)
base = BaseValues.from_nominal(nom)

Configure the system model.

# Grid and filter
par = ACFilterPars(
    L_fc=.073*base.L, L_fg=.073*base.L, C_f=.043*base.C, u_fs0=base.u)
ac_filter = model.ACFilter(par)
ac_source = model.ThreePhaseVoltageSource(w_g=base.w, abs_e_g=base.u)
# Inverter model with constant DC voltage
converter = model.VoltageSourceConverter(u_dc=650)

# Create system model
mdl = model.GridConverterSystem(converter, ac_filter, ac_source)

Configure the control system.

cfg = control.GridFollowingControlCfg(
    L=.073*base.L, nom_u=base.u, nom_w=base.w, max_i=1.5*base.i)
ctrl = control.GridFollowingControl(cfg)

Set the time-dependent reference and disturbance signals.

# Set the active and reactive power references
ctrl.ref.p_g = lambda t: (t > .02)*5e3
ctrl.ref.q_g = lambda t: (t > .04)*4e3

Create the simulation object and simulate it.

sim = model.Simulation(mdl, ctrl)
sim.simulate(t_stop=.1)

Plot the results.

plot(sim, base)

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