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# Simulation of a malfunction of an armature winding of an electric motor

This example simulates the operation of a DC motor with an armature winding malfunction.

## Model diagram:

simple_motor_armature_winding_fault--1751288866661.png

A malfunction of the armature winding of a DC motor is simulated using the Engee Function block, in which, in the Step method code section, a function in the Julia programming language is built in. The function takes two arguments, the angle of rotation and the fraction of a revolution with a malfunction, and returns signals 1 or 0, which characterize a serviceable or faulty condition, respectively.

image.png

The signal from the Engee Function unit enters the Key unit, opening and closing the motor armature circuit.

## Defining the function to load and run the model:

In [ ]: 
function start_model_engee()
    try
        engee.close("simple_motor_armature_winding_fault", force=true) # closing the model
        catch err # if there is no model to close and engee.close() is not executed, it will be loaded after catch.
            m = engee.load("$(@__DIR__)/simple_motor_armature_winding_fault.engee") # loading the model
        end;

    try
        engee.run(m) # launching the model
        catch err # if the model is not loaded and engee.run() is not executed, the bottom two lines after catch will be executed.
            m = engee.load("$(@__DIR__)/simple_motor_armature_winding_fault.engee") # loading the model
            engee.run(m) # launching the model
        end
end
Out[0]:
start_model_engee (generic function with 1 method)

## Running the simulation

Simulation without malfunction:

In [ ]: 
start_model_engee();

Isolation of rotation speed, current and voltage signals from the simout variable:

In [ ]: 
result = simout;
res1 = collect(result)
Out[0]:
5-element Vector{WorkspaceArray}:
 WorkspaceArray{Float64}("simple_motor_armature_winding_fault/Ток, А")
 WorkspaceArray{Float64}("simple_motor_armature_winding_fault/Скорость вращения, об/мин")
 WorkspaceArray{Float64}("simple_motor_armature_winding_fault/Напряжение, В")
 WorkspaceArray{Float64}("simple_motor_armature_winding_fault/Блок имитирующий 
неисправность обмотки якоря.1")
 WorkspaceArray{Float64}("simple_motor_armature_winding_fault/Ideal Rotational Motion Sensor.2")

Malfunction of the armature winding:

In [ ]: 
engee.set_param!("simple_motor_armature_winding_fault/Доля оборота
 характеризующая
 неисправность", "Value" => 0.0833)

Starting a simulation with an armature winding malfunction:

In [ ]: 
engee.run("simple_motor_armature_winding_fault");

Isolation of rotation speed, current and voltage signals from the simout variable:

In [ ]: 
result = simout;
res2 = collect(result)
Out[0]:
5-element Vector{WorkspaceArray}:
 WorkspaceArray{Float64}("simple_motor_armature_winding_fault/Ток, А")
 WorkspaceArray{Float64}("simple_motor_armature_winding_fault/Скорость вращения, об/мин")
 WorkspaceArray{Float64}("simple_motor_armature_winding_fault/Напряжение, В")
 WorkspaceArray{Float64}("simple_motor_armature_winding_fault/Блок имитирующий 
неисправность обмотки якоря.1")
 WorkspaceArray{Float64}("simple_motor_armature_winding_fault/Ideal Rotational Motion Sensor.2")

Writing signals to variables:

In [ ]: 
w_1 = collect(res1[2])
w_2 = collect(res2[2]);

## Visualization of simulation results

Graph of the motor speed without malfunction and with malfunction of the armature winding:

In [ ]: 
using Plots
Plots.plot(w_1[:,1], w_1[:,2], label="Скорость вращения исправного ДПТ, об/мин", linewidth=3)
Plots.plot!(w_2[:,1], w_2[:,2], label="Скорость вращения неисправного ДПТ, об/мин", linewidth=2)
Out[0]:

It can be seen that the steady rotation speed has become lower with the introduction of the malfunction.

In [ ]: 
Plots.plot(w_1[:,1], w_1[:,2], label="Скорость вращения исправного ДПТ, об/мин", linewidth=3)
Plots.plot!(w_2[:,1], w_2[:,2], label="Скорость вращения неисправного ДПТ, об/мин", linewidth=2, xlim=(6.15, 6.50), ylim=(3400, 3700))
Out[0]:

By zooming in on the graph, you can see an unstable engine speed with an armature winding malfunction.

## Conclusions:

Analysis of the simulation results shows that the DC motor reaches a stable rotational speed close to the nominal value (at rated load) within a few seconds after starting; when the fault is activated in steady state, the speed decreases to a new stable value, less than the initial value.

Blocks used in example