diff options
Diffstat (limited to '3574/CH6')
| -rw-r--r-- | 3574/CH6/EX6.1/EX6_1.png | bin | 0 -> 171762 bytes | |||
| -rw-r--r-- | 3574/CH6/EX6.1/EX6_1.sce | 79 | ||||
| -rw-r--r-- | 3574/CH6/EX6.2/EX6_2.png | bin | 0 -> 136097 bytes | |||
| -rw-r--r-- | 3574/CH6/EX6.2/EX6_2.sce | 67 | ||||
| -rw-r--r-- | 3574/CH6/EX6.3/EX6_3.png | bin | 0 -> 111189 bytes | |||
| -rw-r--r-- | 3574/CH6/EX6.3/EX6_3.sce | 32 | ||||
| -rw-r--r-- | 3574/CH6/EX6.4/EX6_4.png | bin | 0 -> 129341 bytes | |||
| -rw-r--r-- | 3574/CH6/EX6.4/EX6_4.sce | 41 |
8 files changed, 219 insertions, 0 deletions
diff --git a/3574/CH6/EX6.1/EX6_1.png b/3574/CH6/EX6.1/EX6_1.png Binary files differnew file mode 100644 index 000000000..f0104e2be --- /dev/null +++ b/3574/CH6/EX6.1/EX6_1.png 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);
+
diff --git a/3574/CH6/EX6.2/EX6_2.png b/3574/CH6/EX6.2/EX6_2.png Binary files differnew file mode 100644 index 000000000..04bb6e898 --- /dev/null +++ b/3574/CH6/EX6.2/EX6_2.png diff --git a/3574/CH6/EX6.2/EX6_2.sce b/3574/CH6/EX6.2/EX6_2.sce new file mode 100644 index 000000000..fc80a231f --- /dev/null +++ b/3574/CH6/EX6.2/EX6_2.sce @@ -0,0 +1,67 @@ +// Example 6.2
+// Determine (a) Capacitance required in series with the auxillary winding
+// in order to obtain a 90 degree phase displacement between the current in
+// the main winding and the current in the auxillary winding at locked rotor
+// (b) Locked rotor torque in terms of the machine constant
+// Page No. 265
+
+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
+f=60; // Frequency
+Tlr=107.1; // Original torque
+
+// (a) Capacitance required in series with the auxillary 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
+
+Theta_awi=90-60.26; // Required phase angle
+Theta_awz=-Theta_awi;
+
+Xc=Xaw-Raw*tand(Theta_awz); // Capacitive reactance
+
+C=1/2*%pi*f*Xc; // Required capacitance
+
+
+// (b) Locked rotor torque in terms of the machine constant
+Zawnew=Raw+%i*Xaw-%i*Xc; // Auxillary winding impedance
+// Complex to Polar form...
+Zawnew_Mag=sqrt(real(Zawnew)^2+imag(Zawnew)^2); // Magnitude part
+Zawnew_Ang=atan(imag(Zawnew),real(Zawnew))*180/%pi; // Angle part
+
+Iawnew_Mag=VT/Zawnew_Mag; // Auxillary winding current magnitude
+Iawnew_Ang=0-Zawnew_Ang; // Auxillary winding current magnitude
+
+Tlenew=Imw_Mag*Iawnew_Mag*sind(90);
+
+// Percent change increase in locked rotor torque
+PI=(Tlenew-Tlr)/Tlr*100;
+
+
+// Display result on command window
+printf("\n Required capacitance = %0.1f microF ",C);
+printf("\n Percent increase in locked rotor torque = %0.0f Percent",PI);
+
+//Note: Capacitor computation is wrong in the book
diff --git a/3574/CH6/EX6.3/EX6_3.png b/3574/CH6/EX6.3/EX6_3.png Binary files differnew file mode 100644 index 000000000..316fdbb36 --- /dev/null +++ b/3574/CH6/EX6.3/EX6_3.png diff --git a/3574/CH6/EX6.3/EX6_3.sce b/3574/CH6/EX6.3/EX6_3.sce new file mode 100644 index 000000000..81a014c57 --- /dev/null +++ b/3574/CH6/EX6.3/EX6_3.sce @@ -0,0 +1,32 @@ +// Example 6.3
+// Determine (a) NEMA standard horsepower rating of machine (b) Required
+// running capacitance (c) Additional capacitance required for starting
+// Page No. 271
+
+clc;
+clear;
+close;
+
+// Given data
+hp=35; // Power in hp
+p=3; // Number of phase
+f=60; // Frequency
+
+
+// (a) NEMA standard horsepower rating of machine
+
+Prated3ph=hp*p/2;
+
+// (b)Required running capacitance
+
+C1=26.5*f;
+
+// (c) Additional capacitance required for starting.
+
+C2=230*f-C1;
+
+// Display result on command window
+printf("\n NEMA standard horsepower rating of machine = %0.1f hp ",Prated3ph);
+printf("\n Required running capacitance = %0.0f microF ",C1);
+printf("\n Additional capacitance required for starting = %0.0f microF ",C2);
+
diff --git a/3574/CH6/EX6.4/EX6_4.png b/3574/CH6/EX6.4/EX6_4.png Binary files differnew file mode 100644 index 000000000..febb6f820 --- /dev/null +++ b/3574/CH6/EX6.4/EX6_4.png diff --git a/3574/CH6/EX6.4/EX6_4.sce b/3574/CH6/EX6.4/EX6_4.sce new file mode 100644 index 000000000..78eb2ca49 --- /dev/null +++ b/3574/CH6/EX6.4/EX6_4.sce @@ -0,0 +1,41 @@ +// Example 6.4
+// Computation of (a) Motor line current and motor phase current (b) Motor line
+// current and motor phase current if one line opens (c) Line and phase
+// currents if the power factor when single phasing is 82.0 percent.
+// Page No. 274
+
+clc;
+clear;
+close;
+
+// Given data
+Vline=2300; // Line voltage
+Fp3ph=3; // Frequency of three phase
+PF=0.844; // Power factor
+PF1=0.820; // 82.2 percent power factor
+Pin=350*746/(0.936*2); // Input power
+
+
+// (a) Motor line current and motor phase current
+
+Iline3ph=Pin/(sqrt(3)*Vline*PF);
+Iphase3ph=Iline3ph;
+
+//(b) Motor line current and motor phase current if one line opens
+
+Iline1ph=(sqrt(3)*Iline3ph*PF)/PF;
+Iphase1ph=Iline1ph;
+
+// (c) Line and phase currents if the power factoe when single phasing is 82.0 percent.
+
+Iline=(Iline1ph*PF)/PF1;
+Iphase=Iline;
+
+// Display result on command window
+printf("\n Motor line current = %0.1f A ",Iline3ph);
+printf("\n Motor phase current = %0.1f A ",Iphase3ph);
+printf("\n Motor line current if one line opens = %0.1f A ",Iline1ph);
+printf("\n Motor phase current if one line opens = %0.1f A ",Iphase1ph);
+printf("\n Line current if the power factor is 82.0 percent = %0.1f A",Iline);
+printf("\n Phase current if the power factor is 82.0 percent = %0.1f A ",Iphase);
+
|
