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/CH8/EX8.3/EX8_3.png | Bin 0 -> 153456 bytes 3574/CH8/EX8.3/EX8_3.sce | 123 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 123 insertions(+) create mode 100644 3574/CH8/EX8.3/EX8_3.png create mode 100644 3574/CH8/EX8.3/EX8_3.sce (limited to '3574/CH8/EX8.3') diff --git a/3574/CH8/EX8.3/EX8_3.png b/3574/CH8/EX8.3/EX8_3.png new file mode 100644 index 000000000..45bcea3a8 Binary files /dev/null and b/3574/CH8/EX8.3/EX8_3.png differ diff --git a/3574/CH8/EX8.3/EX8_3.sce b/3574/CH8/EX8.3/EX8_3.sce new file mode 100644 index 000000000..cbeb0366a --- /dev/null +++ b/3574/CH8/EX8.3/EX8_3.sce @@ -0,0 +1,123 @@ +// Example 8.3 +// Determine (a) System active power (b) Power factor of the synchronous motor +// (c) System power factor (d) Percent change in synchronous field current +// required to adjust the system power factor to unity (e) Power angle of the +// synchronous motor for the conditions in (d) +// Page No. 324 + +clc; +clear; +close; + +// Given data + +Php=400; // Power in hp +eta=0.958; // Efficiency +Pheater=50000; // Resistance heater power +Vs=300; // Synchronous motor voltage +eta2=0.96; // Synchronous motor efficiency +Xs=0.667; // Synchronous reactnace +VT=460; // 3-Phase supply voltage +delta=-16.4; // Power angle + +// (a) System active power +Pindmot=Php*0.75*746/(eta); // Motor operating at three quarter rated load +Psynmot=Vs*0.5*746/(eta2); // Synchronous motor power +Psys=Pindmot+Pheater+Psynmot; +Psysk=Psys/1000; + +// (b) Power factor of the synchronous motor +Pin=Psynmot; // Power input +Vtph=VT/sqrt(3); // Voltage per phase +Ef=-(Pin*Xs)/(3*Vtph*sind(delta)); +// Complex to Polar form... + +Ef_Mag=Ef; // Magnitude part +Ef_Ang=delta; // Angle part
 +Vtph_Mag=Vtph; +Vtph_Ang=0; +//////////// +N01=Ef_Mag+%i*Ef_Ang; // Ef in polar form +N02=Vtph_Mag+%i*Vtph_Ang; // Vt in polar for + +N01_R=Ef_Mag*cos(-Ef_Ang*%pi/180); // Real part of complex number Ef +N01_I=Ef_Mag*sin(Ef_Ang*%pi/180); //Imaginary part of complex number Ef + +N02_R=Vtph_Mag*cos(-Vtph_Ang*%pi/180); // Real part of complex number Vt +N02_I=Vtph_Mag*sin(Vtph_Ang*%pi/180); //Imaginary part of complex number Vt + +FinalNo_R=N01_R-N02_R; +FinalNo_I=N01_I-N02_I; +FinNum=FinalNo_R+%i*FinalNo_I; +// Complex to Polar form... + +FN_M=sqrt(real(FinNum)^2+imag(FinNum)^2); // Magnitude part +FN_A = atan(imag(FinNum),real(FinNum))*180/%pi;// Angle part
 + +Ia_Mag=FN_M/Xs; // Magnitude of Ia +Ia_Ang=FN_A-(-90); // Angle of Ia +Theta=0-Ia_Ang; +FP=cosd(Theta); // Power factor + + +// (c) System power factor +ThetaIndMot=acosd(0.891); // Induction motor power factor +Thetaheat=acosd(1); // Heater power factor +ThetaSyncMot=-34.06; // Synchronous motor power factor +Qindmot=tand(27)*Pindmot; +Qsynmot=tand(ThetaSyncMot)*Psynmot; +Qsys=Qindmot+Qsynmot; +Ssys=Psys+%i*Qsys; // System variable in complex form + +// Complex to Polar form... + +Ssys_Mag=sqrt(real(Ssys)^2+imag(Ssys)^2); // Magnitude part +Ssys_Ang = atan(imag(Ssys),real(Ssys))*180/%pi; // Angle part
 + +FPsys=cosd(Ssys_Ang); // System power factor + +// (d) Percent change in synchronous field current required to adjust the +// system power factor to unity + +Ssynmot=Psynmot-(%i*(-Qsynmot+Qsys)); // Synchronous motor system + +// Complex to Polar form... + +Ssynmot_Mag=sqrt(real(Ssynmot)^2+imag(Ssynmot)^2); // Magnitude part +Ssynmot_Ang=atan(imag(Ssynmot),real(Ssynmot))*180/%pi; // Angle part
 + +Ssynmot1ph_Mag=Ssynmot_Mag/3; // For single phase magnitude +Ssynmot1ph_Ang=Ssynmot_Ang; // For single phase angle + +Iastar_Mag=Ssynmot1ph_Mag/Vtph; // Current magnitude +Iastar_Ang=Ssynmot1ph_Ang-0; // Current angle + +IaNew_Mag=Iastar_Mag; +IaNew_Ang=-Iastar_Ang; + +IaXs_Mag=IaNew_Mag*Xs; +IaXs_Ang=IaNew_Ang-90; + +// Convert these number into complex and then perform addition +// Polar to Complex form + +// Y=29.416<-62.3043 //Polar form number +IaXs_R=IaXs_Mag*cos(-IaXs_Ang*%pi/180); // Real part of complex number +IaXs_I=IaXs_Mag*sin(IaXs_Ang*%pi/180); // Imaginary part of complex number +Efnew=Vtph+IaXs_R+%i*IaXs_I; +// Complex to Polar form... + +Efnew_Mag=sqrt(real(Efnew)^2+imag(Efnew)^2); // Magnitude part +Efnew_Ang=atan(imag(Efnew),real(Efnew))*180/%pi; // Angle part
 + +DeltaEf=(Efnew_Mag-Ef)/Ef; + +// (e) Power angle of the synchronous motor +deltasynmot=Efnew_Ang; + +// Display result on command window +printf("\n System active power = %0.1f kW ",Psysk); +printf("\n Power factor of the synchronous motor = %0.3f leading ",FP); +printf("\n System power factor = %0.3f lagging ",FPsys); +printf("\n Percent change in synchronous field current = %0.2f Percent ",DeltaEf*100); +printf("\n Power angle of the synchronous motor = %0.2f deg ",deltasynmot); -- cgit