AC Induction Motor Using MATLAB Simulink

how to control an AC induction motor using MATLAB Simulink:

  1. Start by opening MATLAB and creating a new Simulink model. Then add the necessary blocks from the Simulink Library Browser to the model.

  2. Add a "AC Induction Motor" block from the "Simscape / Electrical / Specialized Power Systems / Fundamental Blocks" library to the model. This block models the AC induction motor and its behavior.

  3. Add a "Three-Phase Inverter" block from the "Simscape / Electrical / Specialized Power Systems / Power Electronics" library to the model. This block converts the DC voltage into a three-phase AC voltage that is fed to the motor.

  4. Add a "DC Voltage Source" block from the "Simulink / Sources" library to the model. This block represents the DC voltage source that is fed to the inverter.

  5. Connect the blocks as follows: Connect the output of the DC Voltage Source block to the input of the Three-Phase Inverter block. Connect the output of the Three-Phase Inverter block to the input of the AC Induction Motor block.

  6. Add a "Scope" block from the "Simulink / Sinks" library to the model. This block allows you to visualize the output signals.

  7. Add a "PID Controller" block from the "Simulink / Discrete" library to the model. This block will be used to control the speed of the motor.

  8. Connect the output of the AC Induction Motor block to the input of the Scope block. Connect the output of the AC Induction Motor block to the input of the PID Controller block.

  9. Double-click on the PID Controller block to configure its parameters. Set the "Proportional Gain" to 0.5, "Integral Gain" to 0.1, and "Derivative Gain" to 0.05. These values may need to be adjusted depending on the specific motor and control application.

  10. Run the simulation and observe the motor speed and output voltage on the scope. You can adjust the setpoint for the PID controller by changing the "Setpoint" parameter on the block.

This is just a basic example of how to control an AC induction motor using MATLAB Simulink. There are many other control strategies and techniques that can be used depending on the specific application.

 

% AC Induction Motor Control using MATLAB % Motor Parameters Rs = 2; % Stator resistance (ohms) Ls = 0.02; % Stator inductance (H) Rr = 1.5; % Rotor resistance (ohms) Lr = 0.015; % Rotor inductance (H) Lm = 0.01; % Magnetizing inductance (H) J = 0.1; % Moment of inertia (kg*m^2) B = 0.01; % Viscous friction (N*m*s/rad) % Control Parameters Kp = 10; % Proportional gain Ki = 100; % Integral gain Kd = 1; % Derivative gain % Simulation Parameters tspan = [0 10]; % Simulation time dt = 0.001; % Time step % Initial Conditions theta0 = 0; % Initial rotor angle (rad) omega0 = 0; % Initial rotor speed (rad/s) i_s0 = [0; 0]; % Initial stator currents (A) % Reference Speed omega_ref = 100; % Reference speed (rad/s) % Simulink Model mdl = 'ac_induction_motor'; open_system(mdl); % Simulate the model sim(mdl); % Plot the results figure; subplot(2,1,1); plot(tout, omega, 'b'); hold on; plot(tout, omega_ref*ones(size(tout)), 'r--'); xlabel('Time (s)'); ylabel('Speed (rad/s)'); legend('Actual', 'Reference'); title('Motor Speed'); subplot(2,1,2); plot(tout, i_s(:,1), 'b'); hold on; plot(tout, i_s(:,2), 'r'); xlabel('Time (s)'); ylabel('Current (A)'); legend('i_a', 'i_b'); title('Stator Currents');

This code defines the parameters of an AC induction motor and the control parameters for a PID controller. It then simulates the motor using the Simulink model "ac_induction_motor" and plots the results of the simulation, including the motor speed and stator currents. The reference speed is set to 100 rad/s.