MATLAB simulation on speed control of induction motor | Scalar Control of induction motor

Summary

This video tutorial demonstrates simulating the speed control of an induction motor using the DTC (Direct Torque Control) method. Key components include a DC voltage source, semiconductor switch, and an induction motor. The process involves setting up the power and control circuits, including an inverter and a PI controller. The tutorial guides through converting speed to frequency, implementing the control logic, and adjusting parameters for the simulation. The result showcases effective speed control with the motor responding to reference changes, illustrating the practical application of DTC in motor control.

Takeaways

• 🔌 The video discusses simulating the speed control of an induction motor using the DTC (Direct Torque Control) method.
• 🛠️ Key components needed for the simulation include a DC voltage source, a semiconductor switch with an antiparallel diode, and an induction motor.
• 🔄 The process involves preparing both the power circuit and the control circuit, with the inverter being a critical part of the setup.
• 🔩 The motor is changed from round to squirrel cage, and the nominal power lighting is set by default.
• 📏 Current measurement is necessary to monitor the line current, and torque values are kept at one.
• 🔄 A Bus selector is used to connect with the induction motor for controlling the speed.
• 🔄 The mechanical parameter considered is the rotor speed (Ωn), and the rotor angle (Θ) is also taken into account.
• 🔄 The reference speed is converted from radian per second to RPM for the control system.
• 🔄 The speed control involves a PI controller, which adjusts the output based on the difference between the reference and actual speed.
• 🔄 The control circuit includes blocks such as a PI regulator, integrator, divide block, and function blocks for logical operations.
• 🔄 The simulation shows the motor's response to changes in reference speed, demonstrating effective speed control.

Q & A

What is the main topic of the video?

The video is about simulating the speed control of an induction motor using the DTC (Direct Torque Control) method.

What are the essential components needed for the speed control of an induction motor as described in the video?

The essential components include a DC voltage source, a semiconductor switch with an antiparallel diode, and an induction motor.

What is the purpose of building an inverter in this context?

The inverter is built to convert the DC voltage source into a three-phase voltage for the induction motor.

Why is the motor changed from round to squirrel cage in the video?

The motor is changed to a squirrel cage induction motor because it is the type of motor being controlled in this simulation.

What is the role of the current measurement in the simulation?

The current measurement is used to measure the line current, which is essential for controlling the motor's speed.

What is the significance of the Bus selector in the simulation?

The Bus selector is used to connect the control circuit with the induction motor and to control the motor's speed.

What is the purpose of the PI controller in the control circuit?

The PI controller is used to adjust the speed of the motor by comparing the reference speed with the actual speed and making necessary adjustments.

How is the reference speed converted into RPM in the simulation?

The reference speed is converted into RPM by multiplying with 30 by Pi, which accounts for the conversion from radians per second to revolutions per minute.

What is the function of the saturation block in the control circuit?

The saturation block is used to limit the output of the control circuit, ensuring it does not exceed a certain threshold.

How is the frequency converted into the rotor speed (Omega) in the simulation?

The frequency is converted into the rotor speed by multiplying with 2 Pi, which converts the frequency into angular velocity.

What is the role of the function blocks in generating the control signals for the inverter?

The function blocks are used to generate the control signals for the inverter by calculating the sine and cosine of the rotor angle and multiplying them with the magnitude of the rotor speed.

How does the simulation demonstrate the speed control of the induction motor?

The simulation demonstrates speed control by adjusting the reference speed and observing the motor's response to track the reference speed, as shown by the changes in RPM.

Outlines

00:00

🔌 Introduction to Induction Motor Speed Control

The video introduces the process of simulating the speed control of an induction motor using a three-phase voltage source inverter. The presenter outlines the necessary components, including a DC voltage source, a semiconductor switch with an antipolar diode, and the induction motor itself. The video will cover the preparation of both the power circuit and the control circuit. The power circuit involves connecting the inverter to a DC source, while the control circuit involves setting up a PI controller and other necessary blocks to regulate speed. The presenter also mentions the need for current and torque measurements, as well as a Bus selector to interface with the motor.

05:04

🔄 Detailed Control Circuit Setup

This paragraph delves into the specifics of setting up the control circuit for the induction motor speed control. The presenter explains the process of converting reference speed to RPM and feeding it into a PI controller. The output from the PI controller is then used to generate a frequency signal, which is further converted into a rotational speed signal. The control circuit includes function blocks to calculate the magnitude and angle of the motor's rotation. The video also covers the setup of a repeating sequence to generate the necessary pulses for the inverter, ensuring the motor speed is controlled accurately.

10:08

📊 Simulation and Results

The final paragraph describes the simulation process and the results obtained from the speed control setup. The presenter configures the simulation parameters, including the DC link voltage, RMS voltage, and PI controller settings. The simulation is then run to test the speed control, with the reference speed set to 1000 RPM. The presenter demonstrates how the system responds to changes in the reference speed, showing that the motor's speed accurately tracks the reference. The video concludes with a summary of the complete speed control process and an invitation for viewers to ask questions or provide feedback in the comments section.

Keywords

💡Induction Motor

An induction motor is a type of AC electric motor where the electric current in the rotor is induced by the magnetic field of the stator. In the video, the theme revolves around controlling the speed of an induction motor using a specific control method. The script mentions changing the motor from round to squirrel cage, which refers to the type of rotor construction.

💡DC Voltage Source

A DC voltage source is a device that provides a constant direct current (DC) voltage. In the context of the video, a DC voltage source is required to power the inverter, which is a part of the speed control system for the induction motor.

💡Semiconductor Switch

A semiconductor switch is a device that uses semiconductor materials to control the flow of electrical current. In the video, it is used in conjunction with an antipolar diode in the power circuit to control the speed of the induction motor.

💡Antipolar Diode

An antipolar diode is a type of diode that allows current to flow in one direction only, but with a polarity opposite to that of a standard diode. It is used in the power circuit to protect against reverse voltage.

💡Synchronous Motor

A synchronous motor is a type of AC motor in which the rotor rotates at the same speed as the rotating magnetic field produced by the stator. In the script, the induction motor is referred to as a synchronous motor, which is a bit misleading as induction motors are not typically synchronous.

💡Inverter

An inverter is an electrical device that converts direct current (DC) to alternating current (AC). In the video, the inverter is a key component in the power circuit, used to supply power to the induction motor and control its speed.

💡Line Current

Line current refers to the current flowing through the electrical lines in a circuit. In the video, the script mentions the need for a current measurement to measure the line current, which is important for monitoring and controlling the motor's performance.

💡Rotor Speed

Rotor speed is the rotational speed of the rotor in a motor. In the video, the mechanical parameter considered is the rotor speed, denoted by Omega n, which is a critical parameter for speed control.

💡PI Regulator

A PI regulator, or proportional-integral controller, is a type of feedback controller that computes the necessary control action based on the error between a desired setpoint and a measured process variable. In the video, a PI controller is used in the control circuit to regulate the speed of the induction motor.

💡Function Blocks

Function blocks are modular software components that encapsulate a specific function or a set of functions. In the video, function blocks are used in the control circuit to implement mathematical operations and logic, such as sine functions and multiplication, to generate control signals for the inverter.

💡Repeating Sequence

A repeating sequence is a series of values or events that occur in a regular, repeating pattern. In the video, a repeating sequence is used to generate the timing signals for the inverter, which determines the switching pattern of the semiconductor switches.

💡Go To Block

A go to block is a programming construct that allows for the transfer of control to a different part of a program. In the video, a go to block is mentioned as part of the control logic, possibly to manage the flow of the control algorithm.

Highlights

Introduction to simulating the speed control of an induction motor using its color control method.

Requirement of a DC voltage source, semiconductor switch, antipolar diode, and an induction motor for the simulation.

Preparation of the power circuit and the control circuit for the simulation.

Construction of an inverter using a three-phase voltage source.

Modification of the motor from round to squirrel cage and setting the nominal power lighting.

Measurement of line current and torque values for the simulation.

Use of a Bus selector to control the speed of the induction motor.

Setting mechanical parameters such as rotor speed (Omega n) and rotor angle (Theta).

Application of a PI controller for speed regulation.

Conversion of reference speed from radian per second to RPM.

Use of a saturation block to limit the frequency output.

Conversion of frequency into angular velocity (Omega) using multiplication with 2 pi.

Integration of Omega t to obtain Theta and magnitude for the control of the induction motor.

Use of function blocks to write the ma sine Omega t equation.

Comparison of functions with a repeating sequence to generate control pulses for the inverter.

Setting up the complete model with power circuit and control circuit for the simulation.

Adjustment of simulation parameters such as DC link voltage and RMS voltage.

Selection of PI controller parameters and setting the sampling time.

Running the simulation to observe the speed control of the induction motor.

Demonstration of speed control by changing the reference speed and observing the motor's response.

Observation of line current during the simulation.

Conclusion on simulating the speed control of the induction motor using direct self-control.

Invitation for viewers to comment with queries and a reminder to like, share, and subscribe.

Transcripts

hello everyone in this video we are

going to simulate the speed control of

induction motor

using the its color control method

two is to control the speed of the

induction motor what we need we need a

DC voltage source

uh semiconductor switch

with antipolar diode

and we need a synchronous motor that is

the induction motor

okay so first we'll prepare the power

circuit later we will go for the control

circuit

so we have to build the inverter so we

are connecting the inverter

like this

so we are using three phase voltage

source inverter

so this is the DC source

and

now we are changing the motor from round

to the squirrel cage and the nominal

power lighting is as usual is given so

by default setting we are considering

here

and we need a current measurement

to measure the line current

and

we need a torque values we are keeping

is one okay so we need a Bus selector

and we are connecting with the induction

motor

so when we are double clicking on bus so

we want to control the speed of the

motor so the mechanical parameter we are

taking the rotor speed and it will be

Omega n and we are deleting these two

signal one signal too and we are

attacking the rotor angle Theta also to

uh and we are taking the decimal talk so

we just apply and we make a okay so you

can see here

so this is the voltage source also here

we are make this is the total control

circuit so now we are making the power

this is the power circuit so we are

making the control circuits so control

circuit what what we need we need a

eight block

we need a pi regulator Pi controller

and we need

integrator

and divide block

D Max

sorry we need marks

we need a function

01 functions and relational operator

here we will change the symbol of

greater than equal to and we need a

repeating sequence

and we need a prom block and we need a

go to block

we need again

so what we'll do here

we are giving the reference

speed

and

this is the we are changing the name the

speed here

and this suction speed

we are Tech we are converting this

reference speed uh that will be Omega

radian per second so we are converting

into the RPM okay

so to convert into RPM we need to

multiply 30 by 60 by 25 so it will be 30

by Pi so this will be in

RPM and reference minus actual is

feeding to the pi controller and again

this is

this speed is again adding with the pi

output okay and so here we are we will

get the speed so this speed is

converting into the uh frequency so to

convert into into the frequency what we

need in here to convert uh into the

frequency and we are keeping the

saturation block so if it still goes

goes beyond a threshold okay so we are

keeping this 50 and is zero

and again this frequencies to we are

converting into the Omega so we are

multiplying with 2 pi here

so this frequency is converting into the

okay Omega and now we will come to the

Vive control part so this is the Omega

and to integrate the Omega t uh we will

getting the Theta okay and to get the

magnitude uh this is the Omega T and

this Omega TV are just multi dividing

with uh 2 pi into rated frequency okay

so the relative frequency will be

2 pi into 50 so this radius

okay so rated frequency will be 2.250

and the first one will be the Theta and

second one will be the ma okay this will

be the Theta and this will be the m a

and this is passes through

the function blocks

so here we will write

the ma sine Omega t Okay so

you will write you what is U2 the second

uh signals the second signal will be the

ma so it will be the YouTube multiply

with sine Theta okay so this will be U2

into sine Theta we just copy this one

and we'll just paste it over here then

second will be U2 minus sine Theta minus

2

Pi Pi 3

and the third one will be

Plus

2 into

Pi in

Pi by 3.

okay and these functions will be

[Music]

compare with

the repeating sequence

the output will be 0 1 2 this time value

and it will be 1 divided by

1000 and the output value will be

-1 1 and minus 1.

okay so this will be Liberty sequence

and

we are just

copying this

and we are just keeping the

logical operator

and we need or not get to give the

pulses to the inverter

so

here we will see the

S1

really this will be the S2

this will be S3

S4

S5

and has six

okay I'll make a complete setup and uh

I'll come back on the video again

okay so this is a complete model this is

the power circuit and this is the this

is the power circuit and this is the

control circuit for dp5 control so now

we will keep the values so here we are

keeping the 650 is a

DC link voltage and

here the 400 is the RMS voltage as you

can see here so

reference field we are keeping initially

thousand okay and the pi controller

parameters we are keeping as

we are selecting the pi and display time

and we are keeping sampling Time 1 K

power minus 5 and p i value we are

keeping 1 and 10.

so now what we need we need a power

degree block

and we will change this over one e k

power minus 5 and Trust in prison

window

will go to the

model configure parameters

here we will change the

solver type

and we will keep our one E power minus

five

now uh what we'll do we'll just run the

simulation and see whether the speed

control is happening or not

so we have given the references thousand

as you can see here

okay and

we we can see the speed is also at 1000

RPM

now we will change the speed from 0 to

500 and we will see

whether

the speed control is happening or not

so as you can see here we have changed

the speed from 1000 to 500 and the speed

is regulating at uh tracking the

reference as you can see here so now we

will change from thousands to 2500 2000

again and we can see the response of

play speed speed response

and restricting the reference

[Music]

okay

so

by this way we can simulate the speed

control of the induction motor and if

you are looking at the current

so these are the

line current

as you can see these are the line

currents so

this is the complete split control of

the induction motor using dbive control

so if you have any queries regarding

this you can comment me on the comment

sections and don't forget to like share

and subscribe the channel thank you

thank you very much