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-rwxr-xr-x2123/CH4/EX4.1/Exa_4_1.sce23
-rwxr-xr-x2123/CH4/EX4.10/Exa_4_10.sce17
-rwxr-xr-x2123/CH4/EX4.11/Exa_4_11.sce14
-rwxr-xr-x2123/CH4/EX4.12/Exa_4_12.sce17
-rwxr-xr-x2123/CH4/EX4.13/Exa_4_13.sce26
-rwxr-xr-x2123/CH4/EX4.2/Exa_4_2.sce23
-rwxr-xr-x2123/CH4/EX4.3/Exa_4_3.sce29
-rwxr-xr-x2123/CH4/EX4.4/Exa_4_4.sce16
-rwxr-xr-x2123/CH4/EX4.5/Exa_4_5.sce18
-rwxr-xr-x2123/CH4/EX4.6/Exa_4_6.sce20
-rwxr-xr-x2123/CH4/EX4.7/Exa_4_7.sce17
-rwxr-xr-x2123/CH4/EX4.8/Exa_4_8.sce15
-rwxr-xr-x2123/CH4/EX4.9/Exa_4_9.sce18
13 files changed, 253 insertions, 0 deletions
diff --git a/2123/CH4/EX4.1/Exa_4_1.sce b/2123/CH4/EX4.1/Exa_4_1.sce
new file mode 100755
index 000000000..83e634137
--- /dev/null
+++ b/2123/CH4/EX4.1/Exa_4_1.sce
@@ -0,0 +1,23 @@
+//Example No. 4.1
+clc;
+clear;
+close;
+format('v',6);
+
+//Given Data :
+P=30;//KW
+theta1=30;//degree C
+t1=40;//min
+theta2=45;//degree C
+t2=80;//min(t2=2*t1)
+disp("theta=theta_f*(1-exp(-t/T))");
+//Let exp(-t1/T)=a then exp(-t2/T)=a^2
+//theta1/theta2=(1-a)/(1-a^2)
+//a^2*theta1-a*theta2+theta2-theta1=0
+P=[theta1 -theta2 theta2-theta1];//Polynomial for a
+a=roots(P);
+a=a(2);//discarding value 1 as it cant give value of T
+T=-t1/log(a);//min
+disp(T,"Thermal time constant in min : ");
+theta_f=theta1/(1-exp(-t1/T));//degreeC
+disp(theta_f,"Final temperature rise in degree C : ");
diff --git a/2123/CH4/EX4.10/Exa_4_10.sce b/2123/CH4/EX4.10/Exa_4_10.sce
new file mode 100755
index 000000000..9b1fe8eed
--- /dev/null
+++ b/2123/CH4/EX4.10/Exa_4_10.sce
@@ -0,0 +1,17 @@
+//Example No. 4.10
+clc;
+clear;
+close;
+format('v',5);
+
+//Given Data :
+T=90;//min
+t=25;//min
+ShortTimeRating=50;//KW
+Eff=80/100;//Efficiency
+//Let full load rating is P KW and Losses=Pc
+//CuLoss=(P/(P*Eff))^2 & alfa=Pc/CuLoss
+alfa=(Eff)^2;//unitless
+S=sqrt(((1+alfa)/(1-exp(-t/T))-alfa));
+ContinuousRating_fl=ShortTimeRating/S;//KW
+disp(ContinuousRating_fl,"Continuous rating of motor in KW : ");
diff --git a/2123/CH4/EX4.11/Exa_4_11.sce b/2123/CH4/EX4.11/Exa_4_11.sce
new file mode 100755
index 000000000..49a27a458
--- /dev/null
+++ b/2123/CH4/EX4.11/Exa_4_11.sce
@@ -0,0 +1,14 @@
+//Example No. 4.11
+clc;
+clear;
+close;
+format('v',7);
+
+//Given Data :
+Rating=25;//KW
+T=90;//min
+ts=30;//min
+S=sqrt(1/(1-exp(-ts/T)));
+HalfHourRating=S*Rating;//KW
+disp(HalfHourRating,"Half hour rating of motor in KW : ");
+//Answer wrong in textbook.
diff --git a/2123/CH4/EX4.12/Exa_4_12.sce b/2123/CH4/EX4.12/Exa_4_12.sce
new file mode 100755
index 000000000..19256dcc1
--- /dev/null
+++ b/2123/CH4/EX4.12/Exa_4_12.sce
@@ -0,0 +1,17 @@
+//Example No. 4.12
+clc;
+clear;
+close;
+format('v',8);
+
+//Given Data :
+T=60;//min
+t=20;//min
+ShortTimeRating=300;//W
+Eff=80/100;//Efficiency
+//Let full load rating is P KW and Losses=Pc
+//CuLoss=(P/(P*Eff))^2 & alfa=Pc/CuLoss
+alfa=(Eff)^2;//unitless
+S=sqrt(((1+alfa)/(1-exp(-t/T))-alfa));
+ContinuousRating_fl=ShortTimeRating/S;//KW
+disp(ContinuousRating_fl,"Continuous rating of motor in W : ");
diff --git a/2123/CH4/EX4.13/Exa_4_13.sce b/2123/CH4/EX4.13/Exa_4_13.sce
new file mode 100755
index 000000000..42b7ec603
--- /dev/null
+++ b/2123/CH4/EX4.13/Exa_4_13.sce
@@ -0,0 +1,26 @@
+//Example No. 4.13
+clc;
+clear;
+close;
+format('v',7);
+
+//Given Data :
+P=6;//poles
+f=50;//Hz
+MoI=9.5;//Kg-m^2
+Tr=550;//N-m
+S=5/100;//Slip
+Tmax=720;//N-m
+T_LH=1020;//N-m
+th=12;//sec
+Tmin=220;//N-m
+Snl=3/100;//No load slip
+Ns=120*f/P;//rpm
+Nnl=Ns-Ns*Snl;//rpm
+Nrated=Ns-Ns*S;//rpm
+omega_mo=Nnl*2*%pi/60;//rad/s
+omega_mr=Nrated*2*%pi/60;//rad/s
+J=[Tr/(omega_mo-omega_mr)]*[th/log((T_LH-Tmin)/(T_LH-Tmax))];//Kg-m^2
+MoI_flywheel=J-MoI;//Kg-m^2
+disp(MoI_flywheel,"Moment of inertia of flywheel in Kg-m^2 : ");
+//Answer in the book is wrong.
diff --git a/2123/CH4/EX4.2/Exa_4_2.sce b/2123/CH4/EX4.2/Exa_4_2.sce
new file mode 100755
index 000000000..fc4ed0b64
--- /dev/null
+++ b/2123/CH4/EX4.2/Exa_4_2.sce
@@ -0,0 +1,23 @@
+//Example No. 4.2
+clc;
+clear;
+close;
+format('v',6);
+
+//Given Data :
+P=30;//KW
+theta1=20;//degree C
+t1=30;//min
+theta2=30;//degree C
+t2=60;//min(t2=2*t1)
+disp("theta=theta_f*(1-exp(-t/T))");
+//Let exp(-t1/T)=x then exp(-t2/T)=x^2
+//theta1/theta2=(1-x)/(1-x^2)
+//x^2*theta1-x*theta2+theta2-theta1=0
+P=[theta1 -theta2 theta2-theta1];//Polynomial for a
+x=roots(P);
+x=x(2);//discarding value 1 as it cant give value of T
+T=-t1/log(x);//min
+disp(T,"Thermal time constant in min : ");
+theta_f=theta1/(1-exp(-t1/T));//degreeC
+disp(theta_f,"Final temperature rise in degree C : ");
diff --git a/2123/CH4/EX4.3/Exa_4_3.sce b/2123/CH4/EX4.3/Exa_4_3.sce
new file mode 100755
index 000000000..e3e3ccc8f
--- /dev/null
+++ b/2123/CH4/EX4.3/Exa_4_3.sce
@@ -0,0 +1,29 @@
+//Example No. 4.3
+clc;
+clear;
+close;
+format('v',6);
+
+//Given Data :
+P=30;//KW
+theta1=54-30;//degree C
+t1=1;//hour
+theta2=67-30;//degree C
+t2=2;//hour(t2=2*t1)
+disp("theta=theta_f*(1-exp(-t/T))");
+//Let exp(-t1/T)=a then exp(-t2/T)=a^2
+//theta1/theta2=(1-a)/(1-a^2)
+//a^2*theta1-a*theta2+theta2-theta1=0
+P=[theta1 -theta2 theta2-theta1];//Polynomial for a
+a=roots(P);
+a=a(2);//discarding value 1 as it cant give value of T
+T=-t1/log(a);//hour
+theta_f=theta1/(1-exp(-t1/T));//degreeC
+theta_steady=theta_f+30;//degreeC
+disp(theta_steady,"Final steady state temperature in degree C : ");
+disp(T,"Heating time constant in hour : ");
+theta2=theta_f;//degree C
+t=2.7;//hour
+theta=40-30;//degree C
+Tdash=-t/log(theta/theta2);//hour
+disp(Tdash,"Cooling time constant in hour : ");
diff --git a/2123/CH4/EX4.4/Exa_4_4.sce b/2123/CH4/EX4.4/Exa_4_4.sce
new file mode 100755
index 000000000..14884d765
--- /dev/null
+++ b/2123/CH4/EX4.4/Exa_4_4.sce
@@ -0,0 +1,16 @@
+//Example No. 4.4
+clc;
+clear;
+close;
+format('v',6);
+
+//Given Data :
+T=110;//min
+Tdash=150;//min
+t=30;//min
+tdash=45;//min
+theta_f=50;//degree C
+//theta=theta_f-(theta_f-theta1)*exp(-t/T)
+//theta1=theta*exp(-tdash/Tdash);
+theta=(theta_f-theta_f*exp(-t/T))/(1-exp(-tdash/Tdash)*exp(-t/T));//degreeC
+disp(theta,"Maximum temperature rise of the motor in degree C : ");
diff --git a/2123/CH4/EX4.5/Exa_4_5.sce b/2123/CH4/EX4.5/Exa_4_5.sce
new file mode 100755
index 000000000..c66d55714
--- /dev/null
+++ b/2123/CH4/EX4.5/Exa_4_5.sce
@@ -0,0 +1,18 @@
+//Example No. 4.5
+clc;
+clear;
+close;
+format('v',6);
+
+//Given Data :
+theta1=20;//degreeC
+theta2=28;//degreeC
+dthetaBYdt1=0.08;//degreeC/min
+dthetaBYdt2=0.06;//degreeC/min
+//theta=theta_f-(theta_f-theta1)*exp(-t/T)
+//dtheta/dt=(theta_f-theta)/T
+//dthetaBYdt1/dthetaBYdt2=(theta_f-theta1)/(theta_f-theta2)
+theta_f=(theta2*dthetaBYdt1-theta1*dthetaBYdt2)/(dthetaBYdt1-dthetaBYdt2)
+disp(theta_f,"Final temperature rise in degree C : ");
+T=(theta_f-theta1)/dthetaBYdt1;//min
+disp(T,"Heating time constant in min : ");
diff --git a/2123/CH4/EX4.6/Exa_4_6.sce b/2123/CH4/EX4.6/Exa_4_6.sce
new file mode 100755
index 000000000..11a2127a3
--- /dev/null
+++ b/2123/CH4/EX4.6/Exa_4_6.sce
@@ -0,0 +1,20 @@
+//Example No. 4.6
+clc;
+clear;
+close;
+format('v',6);
+
+//Given Data :
+cycle1=50;//hp
+t1=20;//sec
+cycle2=100;//hp
+t2=20;//sec
+cycle3=150;//hp
+t3=10;//sec
+cycle4=120;//hp
+t4=20;//sec
+cycle5=0;//hp
+t5=15;//sec
+hp_rms=sqrt((cycle1^2*t1+cycle2^2*t2+cycle3^2*t3+cycle4^2*t4+cycle5^2*t5)/(t1+t2+t3+t4+t5));//hp
+disp(hp_rms,"hp(rms) for the motor : ");
+disp("We should choose 100hp motor.")
diff --git a/2123/CH4/EX4.7/Exa_4_7.sce b/2123/CH4/EX4.7/Exa_4_7.sce
new file mode 100755
index 000000000..4bb51c350
--- /dev/null
+++ b/2123/CH4/EX4.7/Exa_4_7.sce
@@ -0,0 +1,17 @@
+//Example No. 4.7
+clc;
+clear;
+close;
+format('v',6);
+
+//Given Data :
+t_on=15;//min
+t_off=25;//min
+T=100;//min
+Tdash=140;//min
+theta_f=55;//degree C
+
+//theta=theta_f-(theta_f-theta1)*exp(-t/T)
+//theta1=theta*exp(-tdash/Tdash);
+theta_max=theta_f*[1-exp(-t_on/T)]/(1-exp(-(t_off/Tdash+t_on/T)));//degreeC
+disp(theta_max,"Maximum temperature rise in degree C : ");
diff --git a/2123/CH4/EX4.8/Exa_4_8.sce b/2123/CH4/EX4.8/Exa_4_8.sce
new file mode 100755
index 000000000..d1d63919e
--- /dev/null
+++ b/2123/CH4/EX4.8/Exa_4_8.sce
@@ -0,0 +1,15 @@
+//Example No. 4.8
+clc;
+clear;
+close;
+format('v',6);
+
+//Given Data :
+Rating=100;//KW
+alfa=0.9;//unitless
+ts=20;//min
+T=100;//min
+S=sqrt((1+alfa)/(1-exp(-ts/T)));
+ShortTimeRating=S*Rating;//KW
+disp(ShortTimeRating,"Short time rating in KW : ");
+//Answer is wrong in the textbook.
diff --git a/2123/CH4/EX4.9/Exa_4_9.sce b/2123/CH4/EX4.9/Exa_4_9.sce
new file mode 100755
index 000000000..1565690fb
--- /dev/null
+++ b/2123/CH4/EX4.9/Exa_4_9.sce
@@ -0,0 +1,18 @@
+//Example No. 4.9
+clc;
+clear;
+close;
+format('v',7);
+
+//Given Data :
+T=80;//min
+Tdash=110;//min
+Rating=50;//KW
+ts=15;//min
+S=sqrt(1/(1-exp(-ts/T)));
+ShortTimeRating=S*Rating;//KW
+disp(ShortTimeRating,"Short time rating of motor in KW : ");
+t_off=20;//min
+S=sqrt((1-exp(-(ts/T+t_off/Tdash)))/(1-exp(-(ts/T))))
+DutyRating=S*Rating;//KW
+disp(DutyRating,"Intermittent periodic duty rating in KW : ");
generated by cgit (git 2.34.1) at 2024-12-20 06:11:04 +0000