PMSM Control System Using Matlab Simulink

Here is a sample PMSM (Permanent Magnet Synchronous Motor) control system using MATLAB Simulink:

1. First, we will create a Simulink model for our PMSM control system. Open MATLAB Simulink and create a new model file.

2. Add the following blocks to the model:

• A "PMSM motor" block from the SimPowerSystems library. This block models the PMSM motor itself.
• A "DC voltage source" block from the SimPowerSystems library. This block will provide the input voltage to the motor.
• A "Three-Phase Inverter" block from the SimPowerSystems library. This block will convert the DC voltage to a three-phase AC voltage to drive the motor.
• A "Scope" block from the Simulink library. This block will allow us to visualize the output of the system.

3. Connect the blocks as follows:

• Connect the DC voltage source block to the inverter block.
• Connect the inverter block to the PMSM motor block.
• Connect the output of the PMSM motor block to the input of the Scope block.

4. Now we need to add a control system to regulate the speed of the motor. For this, we will use a PI controller. Add the following blocks to the model:

• A "PI controller" block from the Simulink library. This block will implement the PI control algorithm.
• A "Reference" block from the Simulink library. This block will provide the desired speed reference to the controller.
• A "Gain" block from the Simulink library. This block will scale the error signal before it is passed to the controller.

5. Connect the blocks as follows:

• Connect the output of the Scope block to the input of the PI controller block.
• Connect the output of the Reference block to the input of the Sum block.
• Connect the output of the PI controller block to the input of the Sum block.
• Connect the output of the Sum block to the input of the Gain block.
• Connect the output of the Gain block to the input of the inverter block.

6. Now we need to configure the PI controller block. Double-click on the block to open the "PI Controller" dialog box. Set the following parameters:

• Proportional gain (Kp) = 0.1
• Integral gain (Ki) = 0.01

7. Save the model and run the simulation. You should see the motor speed tracking the reference speed provided by the "Reference" block. You can adjust the reference speed to see how the controller responds.

That's it! This is a basic example of PMSM motor control using MATLAB Simulink. You can further refine the system by adding more sophisticated control algorithms, such as field-oriented control or model predictive control.

Example Code:

% PMSM Motor Control Program % This program controls the speed of a PMSM using a closed-loop control algorithm. % Motor Parameters P = 2; % Number of pole pairs Ld = 0.001; % Direct inductance Lq = 0.001; % Quadrature inductance R = 1; % Resistance J = 0.1; % Moment of inertia B = 0.1; % Damping coefficient Ke = 0.01; % Back-EMF constant Kt = 0.01; % Torque constant % Controller Parameters Kp = 0.1; % Proportional gain Ki = 0.01; % Integral gain Kd = 0.01; % Derivative gain Ts = 0.001; % Sampling time % Simulation Parameters t = 0:Ts:10; % Simulation time N = length(t); % Number of time steps w_ref = 100; % Reference speed (rad/s) % Initial Conditions theta_0 = 0; % Initial rotor position w_0 = 0; % Initial rotor speed i_d0 = 0; % Initial direct current i_q0 = 0; % Initial quadrature current % Define State-Space Model A = [-R/Ld 0 Ke/Ld 0; 0 -R/Lq 0 Ke/Lq; -Kt/J 0 -B/J 0; 0 0 1 0]; B = [0 0; 0 0; 0 0; 1/J 0]; C = [0 0 1 0; 0 0 0 1]; D = [0 0; 0 0]; sys = ss(A,B,C,D); % Calculate Controller Gains [num, den] = pid(Kp,Ki,Kd); G = tf(num, den); Gd = c2d(G, Ts, 'tustin'); [Kp, Ki, Kd] = piddata(Gd, 'all'); % Initialize Arrays theta = zeros(N,1); w = zeros(N,1); i_d = zeros(N,1); i_q = zeros(N,1); u_d = zeros(N,1); u_q = zeros(N,1); % Run Simulation for k = 1:N % Calculate Error e = w_ref - w(k); % Calculate Control Signal u_q(k) = Kp*e + Ki*sum(e) + Kd*(e(k)-e(k-1))/Ts; % Calculate Direct Current i_d(k+1) = i_d(k) + Ts*(u_d(k) - (R*i_d(k) + Ke*w(k))/Ld); % Calculate Quadrature Current i_q(k+1) = i_q(k) + Ts*(u_q(k) - (R*i_q(k) - Ke*w(k))/Lq); % Calculate Torque Te(k) = Kt*(i_d(k)*sin(theta(k)) - i_q(k)*cos(theta(k))); % Calculate Acceleration alpha(k) = (Te(k) - B*w(k))/J; % Calculate Rotor Speed w(k+1) = w(k) + Ts*alpha