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This lecture we will practice some Basic MATLAB Scripts.

›We will start with simple scripts and will discuss some electrical engineering applications.

w = input('Enter power of your device (in watts): ');

h = input('Enter time (in hours): ');

r = input('Enter electricity rate (in dollars per KWH): ');

ec = w * h/1000 * r;

disp(’Your Electricity bill is’)

Disp(ec)

RL = 1:0.01:10;

Vs = 12;

Rs = 2.5;

P = (Vs^2*RL)./(RL+Rs).^2;

plot(RL,P)

xlabel('Load resistance')

ylabel('Power dissipated')

›Ns=1500; % Synchronous speed;

›R1=15.6 ;R2=14;X1=18; X2=23;Xm=260;Vt=400/sqrt(3);

›s = 0.002:0.002:1; % vector of slip

›N = Ns.*(1-s); % Speed, in RPM

›Ws = 2*pi*Ns/60; % Synchronous speed in rad/sec

›Rr = R2./ s; % Rotor resistance

›Zr = j*X2 + Rr; % Total rotor impedance

›Za = j*Xm*Zr./(j*Xm+Zr); % Air-gap impedance

›Zt = R1 + j*X1 +Za; % Terminal impedance

›Ia = Vt ./ Zt; % Terminal Current

›I2 = j*Xm*Ia./(j*Xm+Zr); % Rotor Current

›Pag = 3* (abs(I2)).^2.*Rr; % Air-Gap Power

›Pm = Pag.* (1-s); % Converted Power

›Trq = Pag/ Ws; % Developed Torque

›subplot(2,1,1)

›plot(N, Trq)

›xlabel('Speed in RPM')

›ylabel('Torque (Nm)')

›subplot(2,1,2)

›plot(Ia, Trq)

›xlabel('Load Current')

›ylabel('Torque (Nm)')

›We will start with simple scripts and will discuss some electrical engineering applications.

**Program to calculate Electricity bill.**w = input('Enter power of your device (in watts): ');

h = input('Enter time (in hours): ');

r = input('Enter electricity rate (in dollars per KWH): ');

ec = w * h/1000 * r;

disp(’Your Electricity bill is’)

Disp(ec)

Power transfer vs Load resistance curvePower transfer vs Load resistance curve

RL = 1:0.01:10;

Vs = 12;

Rs = 2.5;

P = (Vs^2*RL)./(RL+Rs).^2;

plot(RL,P)

xlabel('Load resistance')

ylabel('Power dissipated')

**Torque-Speed Curve for a squirrel cage Induction Motor**›Ns=1500; % Synchronous speed;

›R1=15.6 ;R2=14;X1=18; X2=23;Xm=260;Vt=400/sqrt(3);

›s = 0.002:0.002:1; % vector of slip

›N = Ns.*(1-s); % Speed, in RPM

›Ws = 2*pi*Ns/60; % Synchronous speed in rad/sec

›Rr = R2./ s; % Rotor resistance

›Zr = j*X2 + Rr; % Total rotor impedance

›Za = j*Xm*Zr./(j*Xm+Zr); % Air-gap impedance

›Zt = R1 + j*X1 +Za; % Terminal impedance

›Ia = Vt ./ Zt; % Terminal Current

›I2 = j*Xm*Ia./(j*Xm+Zr); % Rotor Current

›Pag = 3* (abs(I2)).^2.*Rr; % Air-Gap Power

›Pm = Pag.* (1-s); % Converted Power

›Trq = Pag/ Ws; % Developed Torque

›subplot(2,1,1)

›plot(N, Trq)

›xlabel('Speed in RPM')

›ylabel('Torque (Nm)')

›subplot(2,1,2)

›plot(Ia, Trq)

›xlabel('Load Current')

›ylabel('Torque (Nm)')