diff options
Diffstat (limited to '3574/CH2')
26 files changed, 578 insertions, 0 deletions
diff --git a/3574/CH2/EX2.1/EX2_1.png b/3574/CH2/EX2.1/EX2_1.png Binary files differnew file mode 100644 index 000000000..32818824f --- /dev/null +++ b/3574/CH2/EX2.1/EX2_1.png diff --git a/3574/CH2/EX2.1/EX2_1.sce b/3574/CH2/EX2.1/EX2_1.sce new file mode 100644 index 000000000..6ff562659 --- /dev/null +++ b/3574/CH2/EX2.1/EX2_1.sce @@ -0,0 +1,22 @@ +// Example 2.1
+// Computation of peak value of sinusoidal flux in a transformer
+// Page No. 42
+
+clc;
+clear all;
+close;
+
+// Given data
+Ep=240; // Voltage in primary coil
+Np=200; // Number of turns in primary coil of transformer
+f=60; // Frequency of source
+
+// Peak value of sinusoidal flux in a transformer
+phimax=Ep/(4.44*Np*f);
+
+
+//Display result on command window
+//printf("\n Peak value of sinusoidal flux in a transformer = %0.4f WB ",phimax);
+
+
+mprintf('Peak value of sinusoidal flux in a transformer = %3.2e Wb', phimax);
diff --git a/3574/CH2/EX2.10/EX2_10.png b/3574/CH2/EX2.10/EX2_10.png Binary files differnew file mode 100644 index 000000000..7501b2129 --- /dev/null +++ b/3574/CH2/EX2.10/EX2_10.png diff --git a/3574/CH2/EX2.10/EX2_10.sce b/3574/CH2/EX2.10/EX2_10.sce new file mode 100644 index 000000000..bd6a7eb4e --- /dev/null +++ b/3574/CH2/EX2.10/EX2_10.sce @@ -0,0 +1,37 @@ +// Example 2.10
+// Computation of (a) Transformer regulation (b) Secondary voltage when the
+// load is disconnected (c) Input primary voltage
+// Page No. 70
+
+clc;
+clear;
+close;
+
+// Given data
+FP=0.75 // Power-factor leading
+RPU=0.013; // Percent resistance
+XPU=0.038; // Percent reactance
+Vrated=600; // Rated voltage of transformer
+TTR=12; // Transformer turns ratio (7200/600)
+ELS=621; // Low side voltage
+
+
+
+// (a) Transformer regulation
+Theta=acosd(FP);
+// Transformer regulation
+RegPU=sqrt( ( (RPU+FP)^2)+ ((XPU-sind(Theta))^2))-1;
+// Transformer regulation in percentage
+RegPU_Per=RegPU*100;
+
+// (b) Secondary voltage when the load is disconnected
+Vnl=(RegPU*Vrated)+Vrated;
+
+// (c) Input primary voltage
+
+EHS=Vnl*TTR;
+
+// Display result on command window
+printf("\n Transformer regulation = %0.4f ",RegPU);
+printf("\n Secondary voltage when the load is disconnected = %0.1f V", Vnl);
+printf(" \n Input primary voltage = %0.0f V",EHS);
diff --git a/3574/CH2/EX2.11/EX2_11.png b/3574/CH2/EX2.11/EX2_11.png Binary files differnew file mode 100644 index 000000000..b5cc05d89 --- /dev/null +++ b/3574/CH2/EX2.11/EX2_11.png diff --git a/3574/CH2/EX2.11/EX2_11.sce b/3574/CH2/EX2.11/EX2_11.sce new file mode 100644 index 000000000..5aa228473 --- /dev/null +++ b/3574/CH2/EX2.11/EX2_11.sce @@ -0,0 +1,29 @@ +// Example 2.11
+// Computation of transformer regulation
+// Page No. 71
+
+clc;
+clear;
+close;
+
+// Given data
+S=10; // Transformer actual rating 10KVA
+Srated=25; // Rated 25KVA
+PF=0.65; // Power factor lagging
+RPU=0.0124; // Percent resistance drop
+XPU=0.014; // Percent reactance drop
+
+// Transformer regulation
+SPU=S/Srated;
+SPU=SPU*100;
+Theta=acosd(PF);
+// Transformer regulation
+RegPU=sqrt( ( (RPU*SPU+PF)^2)+ ((XPU*SPU+sind(Theta))^2))-1;
+// Transformer regulation in percentage
+RegPU_Per=RegPU*100;
+
+// Display result on command window
+printf("\n Transformer regulation = %0.3f ",RegPU);
+printf("\n Transformer regulation in percentage= %0.1f ",RegPU_Per);
+
+// Answer varies due to round off errors
diff --git a/3574/CH2/EX2.12/EX2_12.png b/3574/CH2/EX2.12/EX2_12.png Binary files differnew file mode 100644 index 000000000..ab6db02ff --- /dev/null +++ b/3574/CH2/EX2.12/EX2_12.png diff --git a/3574/CH2/EX2.12/EX2_12.sce b/3574/CH2/EX2.12/EX2_12.sce new file mode 100644 index 000000000..89039d460 --- /dev/null +++ b/3574/CH2/EX2.12/EX2_12.sce @@ -0,0 +1,50 @@ +// Example 2.12
+// Computation of (a) Core loss (b) Core loss if operated at rated current and
+// 0.860 power factor from 375V, 50 HZ supply (c) Efficiency for condition in (b)
+// (d) Efficiency if the load is disconnected
+// Page No. 72
+
+clc;
+clear;
+close;
+
+// Given data
+Srated=50000; // Transformer power rating
+VHS=450; // High side voltage
+RPU=0.0125; // Percent resistance
+XPU=0.0224; // Percent reactance
+FP=0.86; // Power factor lagging
+eta=0.965 // Efficiency
+Hl=0.71 // Hysteresis loss
+Vt60=375 // Supply voltage
+f1=60; // Transformer frequency
+f2=50; // Supply frequency
+
+
+// (a) Core loss
+IHS=Srated/VHS;
+// Using high-side values
+Req_HS=RPU*VHS/IHS; // Equivalent high-side resistance
+Pout=Srated*FP; // Output power
+Pin=Pout/eta; // Input power
+Pcore=Pin-Pout-(IHS^2*Req_HS) // Core loss
+
+// (b) Core loss if operated at rated current and 0.860 power factor from
+// 375V, 50 HZ supply
+Ph60=Hl*Pcore; // Hysteresis loss
+Pe60=Pcore-Ph60; // Eddy current loss
+Pe50=Pe60*(Vt60/VHS)^2; // Eddy current loss
+Ph50=Ph60*(f2/f1)*(Vt60/VHS*f1/f2)^1.6;
+Pcore50=Pe50+Ph50; // Core loss
+
+// (c) Efficiency
+Pout=Vt60*IHS*FP; // Output power
+etanew=Pout/(Pout+Pcore50+IHS^2*Req_HS);
+
+// (d) Efficiency with the load is disconnected
+
+// Display result on command window
+printf("\n Core loss = %0.1f W", Pcore);
+printf("\n Core loss at 375V, 50 Hz supply = %0.2f W",Pcore50);
+printf("\n Efficiency = %0.1f Percent", etanew*100);
+printf("\n Efficiency = 0 with the load is disconnected as Pout=0" )
diff --git a/3574/CH2/EX2.13/EX2_13.png b/3574/CH2/EX2.13/EX2_13.png Binary files differnew file mode 100644 index 000000000..a55bb8127 --- /dev/null +++ b/3574/CH2/EX2.13/EX2_13.png diff --git a/3574/CH2/EX2.13/EX2_13.sce b/3574/CH2/EX2.13/EX2_13.sce new file mode 100644 index 000000000..411fda2ea --- /dev/null +++ b/3574/CH2/EX2.13/EX2_13.sce @@ -0,0 +1,28 @@ +// Example 2.13
+// Determine (a) Efficiency at rated load and 80% power factor
+// (b) 70% load and 80% power factor
+// Page No. 75
+
+clc;
+clear;
+close;
+
+// Given data
+FP=0.80; // Power factor
+PcorePU=0.0045; // Percentage core loss
+RPU=0.0146; // Percentage resistance
+Sload=70; // 70% rated load
+Srated=100; // 100% rated load
+
+// (a) Efficiency at rated load and 80% power factor
+etarated=FP/(FP+RPU+PcorePU);
+
+// (b) Efficiency at 70% load and 80% power factor
+SPU=Sload/Srated;
+IPU=SPU; // I_load is proportional to S_load
+eta=(SPU*FP)/(SPU*FP+PcorePU+IPU^2*RPU) // Efficiency
+
+// Display result on command window
+printf("\n Efficiency at rated load = %0.3f ", etarated);
+printf("\n Efficiency at 70 percent load = %0.3f ",eta);
+disp('There is very little change in efficiency');
diff --git a/3574/CH2/EX2.14/EX2_14.png b/3574/CH2/EX2.14/EX2_14.png Binary files differnew file mode 100644 index 000000000..12b67eb93 --- /dev/null +++ b/3574/CH2/EX2.14/EX2_14.png diff --git a/3574/CH2/EX2.14/EX2_14.sce b/3574/CH2/EX2.14/EX2_14.sce new file mode 100644 index 000000000..135a12fb6 --- /dev/null +++ b/3574/CH2/EX2.14/EX2_14.sce @@ -0,0 +1,59 @@ +// Example 2.14
+// Determine (a) Magnetizing reactance and equivalent core-loss resistance
+// (b) Per unit resistance, reactance and impedance of transformer windings
+// (c) Voltage regulation when operating at rated load and 0.75 power factor lagging
+// Page No. 78
+
+clc;
+clear;
+close;
+
+// Given data
+Poc=521; // Open circuit test power
+Voc=230; // Open circuit voltage
+Vo=230; // Output voltage
+Ioc=13.04; // Open circuit current
+Vsc=160.8; // Short circuit voltage
+Isc=16.3; // Short circuit current
+Psc=1200; // Short circuit power
+S=75000; // Transformer rating
+Vhs=4600; // High side voltage
+FP=0.75; // Power factor lagging
+
+// (a) Magnetizing reactance and equivalent core-loss resistance
+Ife=Poc/Voc; // Current rating
+RfeLS=Vo/Ife; // Core-loss resistance
+Im=sqrt(Ioc^2-Ife^2); // Magnetizing current
+XMLS=Voc/Im; // Magnetizing reactance
+
+// (b) Per unit resistance, reactance and impedance of transformer windings
+ZeqHS=Vsc/Isc; // Equivalent impedance
+ReqHS=Psc/Isc^2; // Equivalent resistance
+XeqHS=sqrt(ZeqHS^2 - ReqHS^2); // Equivalent reactance
+Ihs=S/Vhs; // High side current
+RPU=Ihs*ReqHS/Vhs; // Per unit resistance
+XPU=Ihs*XeqHS/Vhs; // Per unit reactance
+ZPU=RPU+%i*XPU; // Per unit impedance
+// Complex to Polar form...
+ZPU_Mag=sqrt(real(ZPU)^2+imag(ZPU)^2); // Magnitude part
+ZPU_Ang=atan(imag(ZPU),real(ZPU))*180/%pi; // Angle part
+
+// (c) Voltage regulation when operating at rated load and 0.75 power factor lagging
+// Transformer regulation
+Theta=acosd(FP);
+RegPU=sqrt( (RPU+FP)^2 + (XPU+sind(Theta))^2 )-1;
+// Transformer regulation in percentage
+RegPU_Per=RegPU*100;
+
+// Display result on command window
+printf("\n Equivalent core-loss resistance = %0.1f Ohm",RfeLS);
+printf("\n Magnetizing reactance = %0.2f Ohm", XMLS);
+printf("\n Per unit resistance = %0.3f ", RPU);
+printf("\n Per unit reactance = %0.3f ", XPU);
+printf("\n Per unit impedance magnitude = %0.3f ", ZPU_Mag);
+printf("\n Per unit impedance angle = %0.1f ", ZPU_Ang);
+printf("\n Voltage regulation in percentage = %0.2f ", RegPU_Per);
+
+
+
+
diff --git a/3574/CH2/EX2.2/EX2_2.png b/3574/CH2/EX2.2/EX2_2.png Binary files differnew file mode 100644 index 000000000..83787c961 --- /dev/null +++ b/3574/CH2/EX2.2/EX2_2.png diff --git a/3574/CH2/EX2.2/EX2_2.sce b/3574/CH2/EX2.2/EX2_2.sce new file mode 100644 index 000000000..2db51954a --- /dev/null +++ b/3574/CH2/EX2.2/EX2_2.sce @@ -0,0 +1,35 @@ +// Example 2.2
+// Computation of (a) Turns ratio (b) Number of turns in each winding
+// (c) Magnetizing current
+// Page No. 42
+
+clc;
+clear;
+close;
+
+Ep=2400; // Induced emf in primary winding
+Es=240; // Induced emf in primary winding
+Bmax=1.5; // Maximum flux density
+A=50*10^-4; // Cross section area
+f=60; // Frequency
+l=0.667; // Mean length of core
+H=450; // Magnetic field intensity
+
+
+// (a) Turns ratio
+Ts=Ep/Es;
+
+// (b) Number of turns in each winding
+phimax=Bmax*A;
+Np=Ep/(4.44*f*phimax); // Number of primary windings
+Ns=Np/Ts; // Number of secondary windings
+
+//(c) Magnetizing current
+Im=H*l/Np;
+
+
+//Display result on command window
+printf("\n Turns ratio = %0.0f ",Ts);
+printf("\n Number of primary windings = %0.0f turns ",Np);
+printf("\n Number of secondary windings = %0.0f turns ",Ns);
+printf("\n Magnetizing current = %0.2f A ",Im);
diff --git a/3574/CH2/EX2.3/EX2_3.png b/3574/CH2/EX2.3/EX2_3.png Binary files differnew file mode 100644 index 000000000..9709fa671 --- /dev/null +++ b/3574/CH2/EX2.3/EX2_3.png diff --git a/3574/CH2/EX2.3/EX2_3.sce b/3574/CH2/EX2.3/EX2_3.sce new file mode 100644 index 000000000..7e3a125c3 --- /dev/null +++ b/3574/CH2/EX2.3/EX2_3.sce @@ -0,0 +1,54 @@ +// Example 2.3
+// Computation of (a) Exciting current and its quadrature components
+// (b) Equalizing magnetic reactance and equivalent core loss resistance
+// (c) Magnetizing current (d)repeat (a) and (b) for the transformer in the
+// step up mode
+//Page No. 44
+
+clc;
+clear;
+close;
+
+Fp=0.210; // Power factor
+Pcore=138; // Active power
+VT=2400; // Voltage applied to primary
+VT1=240; // 240-V primary voltage -- Second case
+
+
+// (a)Exciting current and its quadrature components
+Theta=acosd(Fp); // Angle
+Thetai=-Theta; // As phase angle of applied voltage is zero
+Ife=Pcore/VT; // Exciting current
+I0=Ife/Fp; // Quadrature component
+Im=tand(Thetai)*Ife; // Quadrature component
+Im=Im*-1;
+
+
+// (b) Equalizing magnetic reactance and equivalent core loss resistance
+XM=VT/Im; // Magnetic reactance
+Rfe=VT/Ife; // Core-loss resistance
+XM=XM/1000;
+Rfe=Rfe/1000;
+//(c) Magnetizing current
+Ife1=Pcore/VT1; // Exciting current
+I01=Ife1/cosd(Thetai);
+IM1=tand(Thetai)*Ife1; // Quadrature component
+IM1=IM1*-1;
+
+//(d) repeat (a) and (b) for the transformer in the step up mode
+XM1=VT1/IM1; // Magnetizing reactance
+Rfe1=VT1/Ife1; // Core-loss resistance
+
+
+
+//Display result on command window
+printf("\n Exciting current = %0.4f A ",Ife);
+printf("\n Exciting current quadrature component 1 = %0.4f A ",I0);
+printf("\n Exciting current quadrature component 2 = %0.3f A ",Im);
+printf("\n Equivalent magnetic reactance = %0.2f kOhm ",XM);
+printf("\n Equivalent core loss resistance = %0.1f kOhm ",Rfe);
+printf("\n Exciting current in step-up mode = %0.3f A ",Ife1);
+printf("\n Exciting current in step-up mode quadrature component 1 = %0.2f A ",I01);
+printf("\n Exciting current in step-up mode quadrature component 2 = %0.2f A ",IM1);
+printf("\n Equivalent magnetic reactance in the step up mode = %0.1f Ohm ",XM1);
+printf("\n Equivalent core loss resistance in the step up mode = %0.1f Ohm ",Rfe1);
diff --git a/3574/CH2/EX2.4/EX2_4.png b/3574/CH2/EX2.4/EX2_4.png Binary files differnew file mode 100644 index 000000000..790cfec9b --- /dev/null +++ b/3574/CH2/EX2.4/EX2_4.png diff --git a/3574/CH2/EX2.4/EX2_4.sce b/3574/CH2/EX2.4/EX2_4.sce new file mode 100644 index 000000000..512f80860 --- /dev/null +++ b/3574/CH2/EX2.4/EX2_4.sce @@ -0,0 +1,44 @@ +// Example 2.4
+// Computation of (a) Secondary voltage (b) Load current
+// (c) Input current to the primary (d) Input impedance looking into the primary terminals
+// Page No. 51
+
+clc;
+clear;
+close;
+
+NHS=200; // Number of turns in primary
+NLS=20; // Number of turns in secondary
+E=120; // Primary voltage magnitude
+ES_Mag=12; // Secondary voltage magnitude
+ES_Ang=0; // Secondary voltage angle
+Zload_Mag=100; // Load magnitude
+Zload_Ang=30; // Load angle
+f=60; // Frequency
+
+// (a) Secondary voltage
+a=NHS/NLS;
+ELS=E/a;
+
+// (b) Load current
+IS_Mag=ES_Mag/Zload_Mag; // Load current magnitude
+IS_Ang=ES_Ang - Zload_Ang; // Load current angle
+
+//(c) Input current to the primary
+Ip_Mag=IS_Mag/a; // Input current to the primary magnitude
+Ip_Ang=IS_Ang; // Input current to the primary angle
+
+//(d) Input impedance looking into the primary terminals
+Zin_Mag=a^2*Zload_Mag; // Input impedance magnitude
+Zin_Ang=Zload_Ang; // Input impedance angle
+Zin_Mag=Zin_Mag/1000;
+
+// Display result on command window
+printf("\n Turns ratio = %0.0f ",a);
+printf("\n Secondary voltage = %0.0f V", ELS);
+printf("\n Load current magnitude = %0.2f A",IS_Mag);
+printf("\n Load current angle = %0.0f deg",IS_Ang);
+printf("\n Input current to the primary magnitude = %0.3f A",Ip_Mag);
+printf("\n Input current to the primary angle = %0.0f deg",Ip_Ang);
+printf("\n Input impedance magnitude = %0.0f KOhm", Zin_Mag);
+printf("\n Input impedance angle = %0.0f deg", Zin_Ang);
diff --git a/3574/CH2/EX2.5/EX2_5.png b/3574/CH2/EX2.5/EX2_5.png Binary files differnew file mode 100644 index 000000000..7423e9ff1 --- /dev/null +++ b/3574/CH2/EX2.5/EX2_5.png diff --git a/3574/CH2/EX2.5/EX2_5.sce b/3574/CH2/EX2.5/EX2_5.sce new file mode 100644 index 000000000..5106ef12c --- /dev/null +++ b/3574/CH2/EX2.5/EX2_5.sce @@ -0,0 +1,81 @@ +// Example 2.5
+// Computation of (a) Equivalent impedance of the transformer referred to the
+// high side (b) Input impedance of the combined transformer and load (C) Actual
+// input voltage at the high side (d) Input impedance if the load is disconnected
+// (e) Exciting current for the conditions in (d)
+// Page No. 60
+
+clc;
+clear;
+close;
+
+// Given data
+S=75000; // Transformer ratings
+VLS=240; // Low side voltage magnitude
+PF=0.96; // Lagging power factor
+VLS_Ang=0; // Low side voltage angle
+VL=240; // Load voltage
+VHS=4800; // High side voltage
+RHS=2.488; // High side resistance
+RLS=0.00600; // Low side resistance
+XHS=4.8384; // High side reactance
+XLS=0.0121 // Low side reactance
+Rfe=44202; // High side resistance
+Xm=7798.6; // High side reactance
+
+
+// (a) Equivalent impedance of the transformer referred to the
+// high side
+ILS=S*1/2/VLS; // Delivering one-half rated load
+Theta=acosd(PF); // Angle
+ThetaI=0-Theta;
+ZloadLS_Mag=VLS/ILS; // Low side impedance magnitude
+ZloadLS_Ang=VLS_Ang-ThetaI; // Low side impedance angle
+
+a=VHS/VL; // Ratio of High side and low side voltages
+Zeq_LS=RHS+a^2*RLS+%i*(XHS+a^2*XLS)
+
+// Complex to Polar form...
+
+Zeq_Mag=sqrt(real(Zeq_LS)^2+imag(Zeq_LS)^2); // Magnitude part
+Zeq_Ang= atan(imag(Zeq_LS),real(Zeq_LS))*180/%pi; // Angle part
+
+// (b) Input impedance of the combined transformer and load
+ZloadHS_Mag=a^2*ZloadLS_Mag; // High side impedance magnitude
+ZloadHS_Ang=ZloadLS_Ang; // High side impedance angle
+
+// Polar to Complex form
+
+ZloadHS_R=ZloadHS_Mag*cos(-ZloadHS_Ang*%pi/180); // Real part of complex number
+ZloadHS_I=ZloadHS_Mag*sin(ZloadHS_Ang*%pi/180); // Imaginary part of complex number
+Zin=ZloadHS_R+%i* ZloadHS_I+Zeq_LS; // Input impedance
+// Complex to Polar form...
+
+Zin_Mag=sqrt(real(Zin)^2+imag(Zin)^2); // Magnitude part
+Zin_Ang= atan(imag(Zin),real(Zin))*180/%pi; // Angle part
+
+// (c) Actual input voltage at the high side
+IHS=ILS/a; // High side current
+VT=IHS*Zin_Mag;
+
+// (d) Input impedance if the load is disconnected
+X=(1/Rfe)+(1/Xm*%i);
+ZinOC=1/X; // Input impedance
+ZinOC_Mag=sqrt(real(ZinOC)^2+imag(ZinOC)^2); // Magnitude part
+ZinOC_Ang= atan(imag(ZinOC),real(ZinOC))*180/%pi; // Angle part
+ZinOC_Ang=ZinOC_Ang*-1;
+
+// (e) Exciting current for the conditions in (d)
+I0_Mag=VT/ZinOC_Mag; // Magnitude of current
+I0_Ang=0-ZinOC_Ang; // Angle of current
+
+// Display result on command window
+printf("\n Equivalent impedance of the transformer magnitude = %0.2f Ohm ",Zeq_Mag);
+printf("\n Equivalent impedance of the transformer angle = %0.1f deg ",Zeq_Ang);
+printf("\n Input impedance of the combined transformer and load magnitude = %0.2f Ohm ",Zin_Mag);
+printf("\n Input impedance of the combined transformer and load angle = %0.2f deg ",Zin_Ang);
+printf("\n Actual input voltage at the high side = %0.0f V", VT);
+printf(" \n Input impedance magnitude when load is disconnected = %0.0f Ohm",ZinOC_Mag);
+printf(" \n Input impedance angle when load is disconnected = %0.2f deg",ZinOC_Ang);
+printf(" \n Exciting current magnitude = %0.2f A",I0_Mag);
+printf(" \n Exciting current angle = %0.0f deg",I0_Ang);
diff --git a/3574/CH2/EX2.6/EX2_6.png b/3574/CH2/EX2.6/EX2_6.png Binary files differnew file mode 100644 index 000000000..c2993561e --- /dev/null +++ b/3574/CH2/EX2.6/EX2_6.png diff --git a/3574/CH2/EX2.6/EX2_6.sce b/3574/CH2/EX2.6/EX2_6.sce new file mode 100644 index 000000000..a1c52385c --- /dev/null +++ b/3574/CH2/EX2.6/EX2_6.sce @@ -0,0 +1,53 @@ +// Example 2.6
+// Computation of (a) Equivalent input impedance of the transformer and load
+// combination (b) Primary current when 2400V is supplied to primary
+// (C) Voltage across the load
+// Page No. 61
+
+clc;
+clear;
+close;
+
+// Given data
+S=37500; // Transformer ratings
+VHS=2400; // High side voltage
+VLS=600; // Low side voltage magnitude
+ZloadLS_Mag=10; // Low side load impedance magnitude
+ZloadLS_Ang=20; // Low side load impedance angle
+Req=2.8; // Equivalent resistance
+Xeq=6; // Equivalent reactance
+VT=2400; // Primary voltage supplied
+
+// (a) Equivalent input impedance of the transformer and load combination
+a=VHS/VLS; // Ratio of High side and low side voltages
+ZloadHS_Mag=a^2*ZloadLS_Mag; // High side load impedance magnitude
+ZloadHS_Ang=ZloadLS_Ang; // High side load impedance angle
+// Polar to Complex form
+ZloadHS_R=ZloadHS_Mag*cos(-ZloadHS_Ang*%pi/180); // Real part of complex number
+ZloadHS_I=ZloadHS_Mag*sin(ZloadHS_Ang*%pi/180); //Imaginary part of complex number
+Zin=Req+%i*Xeq+ZloadHS_R+%i*ZloadHS_I;
+// Complex to Polar form...
+
+Zin_Mag=sqrt(real(Zin)^2+imag(Zin)^2); // Magnitude part
+Zin_Ang = atan(imag(Zin),real(Zin))*180/%pi; // Angle part
+
+// (b) Primary current when 2400V is supplied to primary
+IHS_Mag=VT/Zin_Mag; // Primary current magnitude
+IHS_Ang=0-Zin_Ang; // Primary current angle
+
+// (c) Voltage across the load
+EHS_Mag= IHS_Mag*a^2*ZloadLS_Mag; // Magnitude of voltage across reflected load
+EHS_Ang=IHS_Ang+ZloadLS_Ang; // Angle of voltage across reflected load
+
+ELS_Mag=EHS_Mag/a; // Magnitude of actual voltage across real load
+ELS_Ang=EHS_Ang; // Angle of actual voltage across real load
+
+
+//Display result on command window
+printf("\n Equivalent input impedance of the transformer and load combination magnitude = %0.2f Ohm ",Zin_Mag);
+printf("\n Equivalent input impedance of the transformer and load combination angle = %0.2f deg ",Zin_Ang);
+printf("\n Primary current magnitude = %0.2f A ",IHS_Mag);
+printf("\n Primary current angle = %0.2f deg ",IHS_Ang);
+printf("\n Actual input voltage magnitude = %0.1f V", ELS_Mag);
+printf(" \n Actual input voltage angle = %0.2f deg",ELS_Ang);
+
diff --git a/3574/CH2/EX2.8/EX2_8.png b/3574/CH2/EX2.8/EX2_8.png Binary files differnew file mode 100644 index 000000000..6abb212ec --- /dev/null +++ b/3574/CH2/EX2.8/EX2_8.png diff --git a/3574/CH2/EX2.8/EX2_8.sce b/3574/CH2/EX2.8/EX2_8.sce new file mode 100644 index 000000000..b06468298 --- /dev/null +++ b/3574/CH2/EX2.8/EX2_8.sce @@ -0,0 +1,50 @@ +// Example 2.8
+// Computation of (a) Percent impedance (b) Rated high side current
+// (c) Equivalent resistance and reactance referred to the high side
+// (d) High side fault current if an accidental short circuit of 0.016 Ohm
+// occurs at secondary when 230V impressed across the primary
+// Page No. 66
+
+clc;
+clear;
+close;
+
+// Given data
+R=0.9; // Percent resistance
+X=1.3; // Percent reactance
+VHS=2400; // High side voltage
+PV=75000; // Transformer power rating
+RPU=0.009 // Per unit resistance
+XPU=0.013 // Per unit reactance
+VLS=240; // Low side voltage
+Zshort=0.016; // Short circuit resistance
+VHS_Ang=0; // High side voltage angle
+VHS_Sec=2300; // Secondary high side voltage
+
+// (a) Percent impedance
+Z=sqrt(R^2+X^2);
+
+// (b) Rated high side current
+IHS=PV/VHS;
+
+//(c) Equivalent resistance referred to the high side
+Req_HS=RPU*VHS/IHS;
+// Equivalent reactance referred to the high side
+Xeq_HS=XPU*VHS/IHS;
+
+//(d) High side fault current
+a=VHS/VLS; // Ratio of High side and low side voltages
+Zin=Req_HS+%i*Xeq_HS+a^2*Zshort; // Input impedance
+Zin_Mag=sqrt(real(Zin)^2+imag(Zin)^2); // Magnitude part of input impedance
+Zin_Ang= atan(imag(Zin),real(Zin))*180/%pi; // Angle part
+IHS_Mag=VHS_Sec/Zin_Mag; // High side current magnitude
+IHS_Ang=VHS_Ang-Zin_Ang;
+
+
+//Display result on command window
+printf("\n Percent impedance = %0.2f Percent ",Z);
+printf("\n Rated high side current = %0.2f A", IHS);
+printf(" \n High side equivalent resistance = %0.3f Ohm",Req_HS);
+printf(" \n High side equivalent reactance = %0.3f Ohm",Xeq_HS);
+printf(" \n High side fault current magnitude = %0.0f Ohm",IHS_Mag);
+printf(" \n High side fault current angle = %0.2f deg",IHS_Ang);
diff --git a/3574/CH2/EX2.9/EX2_9.png b/3574/CH2/EX2.9/EX2_9.png Binary files differnew file mode 100644 index 000000000..b265cfde6 --- /dev/null +++ b/3574/CH2/EX2.9/EX2_9.png diff --git a/3574/CH2/EX2.9/EX2_9.sce b/3574/CH2/EX2.9/EX2_9.sce new file mode 100644 index 000000000..334d83df0 --- /dev/null +++ b/3574/CH2/EX2.9/EX2_9.sce @@ -0,0 +1,36 @@ +// Example 2.9
+// Computation of (a) Transformer regulation (b) Secondary voltage when the
+// load is disconnected (c) Input primary voltage
+// Page No. 69
+
+clc;
+clear;
+close;
+
+// Given data
+FP=0.75 // Power-factor lagging
+RPU=0.013; // Percent resistance
+XPU=0.038; // Percent reactance
+Vrated=600; // Rated voltage of transformer
+TTR=12; // Transformer turns ratio (7200/600)
+ELS=621; // Low side voltage
+
+
+
+// (a) Transformer regulation
+Theta=acosd(FP);
+// Transformer regulation
+RegPU=sqrt( ( (RPU+FP)^2)+ ((XPU+sind(Theta))^2))-1;
+// Transformer regulation in percentage
+RegPU_Per=RegPU*100;
+
+// (b) Secondary voltage when the load is disconnected
+Vnl=(RegPU*Vrated)+Vrated;
+
+// (c) Input primary voltage
+EHS=ELS*TTR;
+
+// Display result on command window
+printf("\n Transformer regulation = %0.3f ",RegPU);
+printf("\n Secondary voltage when the load is disconnected = %0.0f V", Vnl);
+printf(" \n Input primary voltage = %0.0f V",EHS);
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