Engee documentation
Notebook

Star-delta starting of induction motor

This example will demonstrate a simulated star-delta start-up of a squirrel cage induction motor (model induction_machine_starting.engee). This example shows how to model a star-delta starting circuit for an induction machine. When power is connected to the machine via switch S1, switch S2 is initially off, causing the machine to be connected in a star circuit. As soon as the machine approaches synchronous speed, switch S2 is actuated, thereby reconnecting the machine in a delta configuration. The star-delta starting scheme for an induction motor provides low mains currents at start-up, and once the motor has reached the speed required for its operation, the switchover to delta switching takes place, allowing operation at 100% load without any problems.

General view of the models

Engee model:

model_2.png

Realisation of the model run using software control:

Loading the required libraries:

In [ ]:
using Plots
gr();
using DataFrames

Loading the model:

In [ ]:
model_name = "induction_machine_starting"
model_name in [m.name for m in engee.get_all_models()] ? engee.open(model_name) : engee.load( "$(@__DIR__)/$(model_name).engee");

Running a loaded model:

In [ ]:
results = engee.run(model_name)
Out[0]:
Dict{String, DataFrame} with 4 entries:
  "i_c" => 20001×2 DataFrame…
  "i_b" => 20001×2 DataFrame…
  "w"   => 20001×2 DataFrame…
  "i_a" => 20001×2 DataFrame

Read instantaneous load current and shaft speed data:

In [ ]:
t = results["i_a"].time;
i_a = results["i_a"].value;
i_b = results["i_b"].value;
i_c = results["i_c"].value;
w = results["w"].value;

Loading and visualisation of simulation data

In [ ]:
plot(t, [i_a i_b i_c], label=["Ток фазы А" "Ток фазы В" "Ток фазы С"])
plot!(ylabel = "Мгновенное значение тока, А", xlabel="Время, c")
Out[0]:
In [ ]:
plot(t, w, label="Скорость вращения вала")
plot!(ylabel = "Скорость вращения, об/мин", xlabel="Время, c")
Out[0]:

Conclusions:

In this example, tools were used to command control an induction motor starting model. Simulation results were imported into a script, visualised, using interactive plots from the Plots library.