initial commit / add all books

9 files changed, 103 insertions, 0 deletions

diff --git a/371/CH16/EX16.1/16_1.sci b/371/CH16/EX16.1/16_1.sci
new file mode 100755
index 000000000..eae7efcea
--- /dev/null
+++ b/371/CH16/EX16.1/16_1.sci
@@ -0,0 +1,6 @@
+//Faults and Protection//

+//Example 16.1//

+V=415;//AC input voltage//

+Vf=2.53;//voltage safety factor//

+PIV=2*sqrt(2)*V*Vf;//peak inverse voltage of the device//

+printf('peak inverse voltage of the device=PIV=%fVolts',PIV);
\ No newline at end of file
diff --git a/371/CH16/EX16.2/16_2.sci b/371/CH16/EX16.2/16_2.sci
new file mode 100755
index 000000000..9f3f8fdf5
--- /dev/null
+++ b/371/CH16/EX16.2/16_2.sci
@@ -0,0 +1,6 @@
+//Faults and Protection//

+//Example 16.2//

+V=415;//AC input voltage in volts//

+PIV=1350;//peak inverse voltage of the device in volts//

+Vf=PIV/(sqrt(2)*V);//voltage safety factor of the device//

+printf('voltage safety factor of the device=Vf=%f',Vf);
\ No newline at end of file
diff --git a/371/CH16/EX16.3/16_3.sci b/371/CH16/EX16.3/16_3.sci
new file mode 100755
index 000000000..4263d10ee
--- /dev/null
+++ b/371/CH16/EX16.3/16_3.sci
@@ -0,0 +1,7 @@
+//Faults and Protection//
+//Example 16.3//
+P=100;//input power in KVA//
+Xt=0.04;//limiting ac reactance value//
+Fov=2;//current ovarload factor//
+Pc=Xt*P*Fov;//choke power of the converter in KVA//
+printf('choke power of the converter=Pc=%fKVA',Pc);
\ No newline at end of file
diff --git a/371/CH16/EX16.4/16_4.sci b/371/CH16/EX16.4/16_4.sci
new file mode 100755
index 000000000..702118e3a
--- /dev/null
+++ b/371/CH16/EX16.4/16_4.sci
@@ -0,0 +1,11 @@
+//Faults and Protection//

+//Example 16.4//

+Ls=0.1;//stray inductance in the circuit in milli Henry//

+L=2*Ls;//inductance required for the snubber ckt for protection in mH//

+Im=250;//mean value of current in amp//

+C=2.5*Im;//capacitance required for the snubber ckt in nano Farads//

+printf('capacitance in snubber circuit=C=%fnanofarads',C);

+R=2*100*sqrt(L/C);//resistance in snubber circuit in Kilo Ohms//

+printf('\nResistance in snubber circuit=R=%fKilo Ohms',R);

+Pdif=1*30;//permissible dv/dt of the circuit//

+printf('\nPermissible dv/dt of the circuit=%fMV/s',Pdif);

diff --git a/371/CH16/EX16.5/16_5.sci b/371/CH16/EX16.5/16_5.sci
new file mode 100755
index 000000000..7cd0e8bae
--- /dev/null
+++ b/371/CH16/EX16.5/16_5.sci
@@ -0,0 +1,7 @@
+//Faults and Protection//

+//Example 16.5//

+V=240;//dc input voltage in volts//

+Vh=25;//each selenium plate handling voltage in volts//

+N=V/Vh;//number of plates in series in the circuit//

+printf('number of plates in series in the circuit=N=%f',N);

+printf('\nso we will use 10 plates in the circuit');
\ No newline at end of file
diff --git a/371/CH16/EX16.6/16_6.sci b/371/CH16/EX16.6/16_6.sci
new file mode 100755
index 000000000..5161a10a0
--- /dev/null
+++ b/371/CH16/EX16.6/16_6.sci
@@ -0,0 +1,8 @@
+//Faults and Protection//

+//Example 16.6//

+V=230;//ac input voltage in volts//

+Vh=30;//each selenium plate handling voltage in volts//

+N=((V/Vh)1)+1;//number of plates in series in each direction in the ckt//

+printf('number of plates in series in each direction=N=%f',N);

+Nt=2*N;//total number of plates in series in the circuit//

+printf('\ntotal number of plates in series in both directions=Nt=%f',Nt);
\ No newline at end of file
diff --git a/371/CH16/EX16.7/16_7.sci b/371/CH16/EX16.7/16_7.sci
new file mode 100755
index 000000000..3ea7982d0
--- /dev/null
+++ b/371/CH16/EX16.7/16_7.sci
@@ -0,0 +1,19 @@
+//Faults and Protection//

+//Example 16.7//

+V=415;//ac input voltage in volts//

+Vdc=440;//supplied voltage to dc motor in volts//

+Vh=30;//each selenium plate handling voltage in volts//

+N=Vdc/Vh;//number of plates in series in each direction in the ckt//

+N=15;

+printf('number of plates in each branch=N=%f',N);

+Nt=3*N;//total number of plates in series in the circuit//

+printf('\ntotal number of plates=Nt=%f',Nt);

+Ipa=136;//peak armature current in amperes//

+T=30;//time constant in milliseconds//

+R=0.175;//Armature resistance in Ohms//

+L=T*R;//Armature circuit Inductance in milliHenry//

+printf('\nArmature circuit inductance=L=%fmH',L);

+Es=0.5*L*Ipa^2*10^-3;//Energy stored in armature circuit in wattsec//

+printf('\nEnergy stored in armature circuit=Es=%fwattsec',Es);

+Ed=Es/N;//Energy dissipated per plate in wattsec//

+printf('\nEnergy dissipated per plate=Ed=%fwattsec',Ed);

diff --git a/371/CH16/EX16.8/16_8.sci b/371/CH16/EX16.8/16_8.sci
new file mode 100755
index 000000000..8f5251c34
--- /dev/null
+++ b/371/CH16/EX16.8/16_8.sci
@@ -0,0 +1,34 @@
+//Faults and Protection//

+//Example 16.8//

+printf(' As the thyristor converter is required for both rectification/inversion and as the fuse has to protect against inverter fault also,fuses will have to be located in branches and minimum of six fuses will be required.');

+Id=765;//dc current in amps//

+Ib=0.58*Id;//Current through each branch in amps//

+printf('\n Current through each thyristor branch=Ib=%famps',Ib);

+printf('\n Inverter short through:');

+printf('\n Voltage causing inverter shoot through current=E2+eb');

+printf('\n Maximum value of the voltage causing inverter shoot through current=sqrt(2)*E2+eb');

+//E2=Input voltage of the thyristor converter//

+//eb=Back emf of the motor causing regeneration//

+printf('\n Recovery voltage across each fuse=Ew=E2/2+eb/(2*sqrt(2))');

+//eb=Edi*cos(5*%pi/6)//

+//Edi=Maximum dc value of the voltage on the thyristor converter=1.35*E2 for 6 pulse connection under discussion//

+//Angle of 5*%pi/6 is normally taken as the limiting value of the firing angle beyond which inverter shoot through will takes place//

+printf('\n Further fuse rated voltage=En=E2+Eb/sqrt(2)=2*Ew');

+E2=500;

+Ew=0.914*E2;

+printf('\n Ew=%fvolts',Ew);

+En=2*Ew;

+printf('\n En=%fvolts',En);

+printf('\n Ew/En=455/1000=0.45');

+printf('\n Ita^2=1.4*Itm^2\n Total It^2 value of fuse=Ita^2+Itm^2=2.4*Itm^2=2.4*65000A^2s=1,56,000A^2s');

+printf('\n I^2t of thyristor=1,90,000A^2s');

+printf('\n I^2t of thyristor>I^2t of fuse or the fuse will protect the device');

+printf('\n Short circuit on dc Bushers');

+//The fault is shown in fig 16.9(c) along with path of the fault current//

+printf('\n Maximum voltage causing fault current=sqrt(2)*E2');

+printf('\n Recovery voltage across each fuse=0.5*E2=0.5*500=250volts');

+printf('\n Ew/En=250/1000=0.25 and at this value Ita^2=0.4*Itm^2');

+printf('\n It^2 of fuse=Ita^2+Itm^2=1.4*Itm^2=1.4*65000=91000A^2s');

+printf('\n It^2 of thyristor=1,50,000A^2s\n It^2 of thyristor>>It^2 of fuse\n the fuse will protect thyristor');

+printf('\n Puncture of a device:\n In this case also maximum voltage causing fault current=sqrt(2)*E2\n Thus as per case It^2 value of thyristor will be more than that of fuse');

+printf('\n Short circuit between phase and bridge:\n In this case also as per case above fuse will protect device\n Thus the fuse will protect for all faults');

diff --git a/371/CH16/EX16.9/16_9.sci b/371/CH16/EX16.9/16_9.sci
new file mode 100755
index 000000000..d9d89d492
--- /dev/null
+++ b/371/CH16/EX16.9/16_9.sci
@@ -0,0 +1,5 @@
+//Faults and Protection//
+//Example 16.9//
+printf('    Thus from the table we see at a value of circuit inductance 1.592mH,I^2t value of breaker is 4.9*10^5A^2s and selectivity between fuse and breakeris I^2tFuse/I^2t Breaker=4*10^5/4.97*10^5=1.01');
+printf('\nAs this is just the border case we will go for the next value of inductancei.e,1.91mH.where selectivity=5*10^5/4.34*10^5=1.18');
+printf('\nThus the additional inductance required is=1.91-1.273=0.637mH');
\ No newline at end of file