Project - Speed Control of a Direct Current (DC) motor

• Here the Speed control of a DC motor is either done manually by the operator or by means of an automatic control device.
• This is different to speed regulation where the speed is trying to be maintained or regulated against the natural change in speed due to a change in the load on the shaft

• so  the speed can be varied by changing:

  1. The terminal voltage of the armature V
  2. The external resistance in armature circuit R_a
  3. The flux per pole 

• So Terminal voltage and external resistance involve a change that affects the armature circuit while flux involves a change in the maginetic field

• so Therefore speed control of DC motor can be classified into:

  1. Armature Control Methods
  2. Field Control Methods                                                           

SIMUKINK MODEL

• Here first we need to creat simulink model of the DC motor and make it as subsytem called the DC motor 
• So next the subsytem of DC motor is connected to the discrete PID controller which helps in maintaining the desired speed 
• So after the PID controller we need to start with the kp ki kd such as 1.0 1.0 0 after tunin accordingly so by this we can adjust the kp ki kd values as 31.5 82.3 2.3 
• Which is used to obtaine the control design objectives

SIMULINK MODEL OF DC MOTOR

MATLAB SCRIPT

% This file contains the design paramters to model a Dc motor
J = 0.01;  % momemt of inertia
B = 0.1;    % motor friction
Km = 0.01;  % back emf
Kt = 0.01;   % Motor torque constant
Ra = 1.0;    % aramture resistance
La = 0.5;    % aramture inductance

 OUTPUT RESULT OF THE SUBSYSTEM

 

DESIGN WITH PID CONTROLLER

 

PID CONTROLLER PARAMETER

Kp =1 ki = 1 kd 0

But after tuning we set kp ki kd to 31.5 82.3 2.3 which is used to obtaine the control objectives of the settling time overshoot time and steady state error 

SETTING TIME AS 1.5 SEC

 

PLOT FOR STEADY STATE ERROR AT LESS THAN 5%

 

FINAL PLOT

 

FOR MAINTAIN STABILITY;

CASE 1

     MAINTAIN SPEED OF MOTOR AT 100

CASE 2

MAINTAIN SPPED AT 230V

      In this both case plot are remain same , hence we considered that dc motor is maintained at desired speed.

CONCLUTION ;

 In this project, we get a knowledge about  Proportional Integral and Derivative PID control design using simulink model.

Also trained to design, develop and test a controller to maintain a desired speed for the DC motor.