From 7f60ea012dd2524dae921a2a35adbf7ef21f2bb6 Mon Sep 17 00:00:00 2001 From: prashantsinalkar Date: Tue, 10 Oct 2017 12:27:19 +0530 Subject: initial commit / add all books --- 3574/CH6/EX6.1/EX6_1.sce | 79 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) create mode 100644 3574/CH6/EX6.1/EX6_1.sce (limited to '3574/CH6/EX6.1/EX6_1.sce') diff --git a/3574/CH6/EX6.1/EX6_1.sce b/3574/CH6/EX6.1/EX6_1.sce new file mode 100644 index 000000000..1c9278007 --- /dev/null +++ b/3574/CH6/EX6.1/EX6_1.sce @@ -0,0 +1,79 @@ +// Example 6.1 +// Determine (a) Locked rotor current in each winding (b) Phase displacement +// angle between the two currents (c) Locked rotor torque in terms of the +// machine constant (d) External resistance required in series with the auxillary +// winding in order to obtain a 30 degree phase displacement between the currents +// in the two windings (e) Locked rotor torque for the conditions in (d) +// (f) Percent increase in locked rotor torque due to the addition of external +// resistance +// Page No. 257 + +clc; +clear; +close; + +// Given data +Zmw=2.00+%i*3.50 // Main winding impedance +Zaw=9.15+%i*8.40 // Auxillary winding impedance +VT=120; // Transformer voltage +Xaw=8.40; // Auxillary winding reactance +Raw=9.15; // Auxillary winding resistance + +// (a) Locked rotor current in each winding +// Main winding impedance in polar form +// Complex to Polar form... +Zmw_Mag=sqrt(real(Zmw)^2+imag(Zmw)^2); // Magnitude part +Zmw_Ang=atan(imag(Zmw),real(Zmw))*180/%pi; // Angle part
 + +// Auxillary winding impedance in polar form +// Complex to Polar form... +Zaw_Mag=sqrt(real(Zaw)^2+imag(Zaw)^2); // Magnitude part +Zaw_Ang=atan(imag(Zaw),real(Zaw))*180/%pi; // Angle part
 + +// Main winding current +Imw_Mag=VT/Zmw_Mag; // Main winding current magnitude +Imw_Ang=0-Zmw_Ang; // Main winding current angle + +// Auxillary winding current +Iaw_Mag=VT/Zaw_Mag; // Auxillary winding current magnitude +Iaw_Ang=0-Zaw_Ang; // Auxillary winding current angle + +// (b) Phase displacement angle between the two currents +Alpha=abs(Imw_Ang-Iaw_Ang); + +// (c) Locked rotor torque in terms of the machine constant +Tlr=Imw_Mag*Iaw_Mag*sind(Alpha); + +// (d) External resistance required in seris with the auxillary winding in +// order to obtain a 30 degree phase displacement between the currents in the +// two windings +Theta_awi=Imw_Ang+30; // Required phase angle +Theta_awz=-Theta_awi; +Rx=(Xaw/tand(Theta_awz))-Raw; + +// (e) Locked rotor torque for the conditions in (d) +Zawnew=Raw+Rx+%i*Xaw; // Auxillary winding impedance +// Complex to Polar form... +Zmwnew_Mag=sqrt(real(Zawnew)^2+imag(Zawnew)^2); // Magnitude part +Zmwnew_Ang=atan(imag(Zawnew),real(Zawnew))*180/%pi; // Angle part
 + +Iawnew_Mag=VT/Zmwnew_Mag; // Auxillary winding current magnitude +Iawnew_Ang=0-Zmwnew_Ang; // Auxillary winding current magnitude +Tlenew=Imw_Mag*Iawnew_Mag*sind(30); + +// (f) Percent increase in locked rotor torque due to the addition of external +// resistance +PI=(Tlenew-Tlr)/Tlr*100; + + +// Display result on command window +printf("\n Main winding current magnitude = %0.1f A ",Imw_Mag); +printf("\n Main winding current angle = %0.1f deg ",Imw_Ang); +printf("\n Auxillary winding current magnitude = %0.2f A ",Iaw_Mag); +printf("\n Auxillary winding current angle = %0.1f deg ",Iaw_Ang); +printf("\n Phase displacement angle = %0.1f deg ",Alpha); +printf("\n Locked rotor torque in terms of the machine constant = %0.2f.Ksp ",Tlr); +printf("\n External resistance required = %0.2f Ohm ",Rx); +printf("\n Locked rotor torque = %0.1f.Ksp ",Tlenew); +printf("\n Percent increase in locked rotor torque = %0.1f Percent increase ",PI); + -- cgit