initial commit / add all books

5 files changed, 172 insertions, 0 deletions

diff --git a/3035/CH15/EX15.1/Ex15_1.sce b/3035/CH15/EX15.1/Ex15_1.sce
new file mode 100755
index 000000000..24b38a335
--- /dev/null
+++ b/3035/CH15/EX15.1/Ex15_1.sce
@@ -0,0 +1,30 @@
+
+// Variable Declaration
+G = 50.0            //Rating of machine(MVA)
+f = 50.0            //Frequency of turbo generator(Hz)
+V = 11.0            //Voltage rating of machine(kV)
+H = 9.0             //Cycle corresponding to 180 ms
+P_0 = 40.0          //Pre-fault output power(MW)
+delta_0 = 20.0      //Rotor angle at instant of fault(degree)
+
+funcprot(0)
+// Calculation Section
+P_0_close = 0                              //Output power at instant of reclosing(MW)
+P_a = P_0 - P_0_close                      //Net accelerating power(MW)
+delta_sqr = P_a*180*f/(G*H)                //double derivative(elect.degrees/sec^2)
+
+
+function ans =  integrand1(t)                         //intgs the double derivative to 800*t
+    ans = delta_sqr
+endfunction    
+a = intg(0, 180*10**-3,integrand1)   //Rotor velocity(electrical degrees/sec)
+
+function ans = integrand2(t)                         //intgs the double derivative to 400*t^2
+    ans = delta_sqr*t
+endfunction    
+b = intg(0, 180*10**-3,integrand2)
+delta = delta_0 + b                        //Rotor angle(electrical degrees)
+
+// Result Section
+printf('Rotor angle at the instant of reclosure = %.2f electrical degrees' ,delta)
+printf('Rotor velocity at the instant of reclosure = %.1f electrical degrees/sec' ,a)
diff --git a/3035/CH15/EX15.2/Ex15_2.sce b/3035/CH15/EX15.2/Ex15_2.sce
new file mode 100755
index 000000000..38ff030b8
--- /dev/null
+++ b/3035/CH15/EX15.2/Ex15_2.sce
@@ -0,0 +1,26 @@
+
+// Variable Declaration
+V = 1.0         //Infinite bus voltage(p.u)
+E = 1.0         //e.m.f of finite generator behind transient reactance(p.u)
+X_T = 0.8       //Transfer reactance(p.u)
+P_i = 0.5       //Input power(p.u)
+P_i_d = 0.8     //p.u
+P_0 = 0.5       //Output power(p.u)
+P = 0.5         //Power(p.u)
+
+// Calculation Section
+P_m = E*V/X_T                       //Amplitude of power angle curve(p.u)
+delta_0 = asin(P_i/P_m)        //Radians
+delta = asin(P_i_d/P_m)        //Radians
+delta_m = %pi-delta             //Radians
+A_acc = P_i_d*(delta-delta_0)-P_m*(cos(delta_0)-cos(delta))   //Possible area of a// Result Sectioneleration
+A_dec = P_m*(cos(delta)-cos(delta_m))-P_i_d*(delta_m-delta)   //Possible area of deceleration
+
+// Result Section
+if (A_acc < A_dec) then
+    printf('System is stable')
+    stability = A_dec/A_acc
+    printf('Margin of stability = %.2f' ,stability)
+else
+    printf('System is not stable')
+end
diff --git a/3035/CH15/EX15.3/Ex15_3.sce b/3035/CH15/EX15.3/Ex15_3.sce
new file mode 100755
index 000000000..e80d4baf8
--- /dev/null
+++ b/3035/CH15/EX15.3/Ex15_3.sce
@@ -0,0 +1,44 @@
+
+// Variable Declaration
+x = 0.25        //Transient reactance(p.u)
+E = 1.0         //e.m.f of finite generator behind transient reactance(p.u)
+x_T = 0.1       //Reactance of transformer(p.u)
+x_L = 0.4       //Reactance of one line(p.u)
+P_i = 0.25      //Pre-fault power(p.u)
+
+// Calculation Section
+X_T = x+x_T+(x_L/2)                 //Transfer reactance at pre-fault state(p.u)
+P_m = E**2/X_T                      //Amplitude of power angle curve at pre-fault state(p.u)
+X_T1 = 1.45                         //Transfer reactance b/w finite generator & infinite bus at faulty state(p.u).Refer texbook problem for figure
+P_m1 = E**2/X_T1                    //Amplitude of power angle curve at faulty state(p.u)
+r1 = X_T/X_T1
+delta_0 = asin(P_i/P_m)        //Radians
+delta_1 = asin(P_i/(r1*P_m))   //Radians
+delta_m = %pi - delta_1         //Radians
+
+function ans = integrand1(delta)
+    ans = r1*P_m*sin(delta)
+endfunction
+a = intg(delta_0, delta_1,integrand1)
+
+A_acc = P_i*(delta_1-delta_0) - a 
+
+function ans = integrand2(delta)
+    ans = r1*P_m*sin(delta)
+endfunction    
+
+b = intg( delta_1, delta_m,integrand2)
+A_dec = b - P_i*(delta_m-delta_1)
+limit = 0.5648                      //Obtained by iterations.Refer textbook.Here assigned directly.
+
+
+// Result Section
+if(A_acc < A_dec) then
+    printf('System is Stable')
+    stability = A_dec/A_acc
+    printf('Margin of stability = %.2f' ,stability)
+else
+    printf('System is not stable')
+end    
+printf('Transient stability limit = %.4f p.u' ,limit)
+printf('\nNOTE : ERROR : angle delta_0 = 7.9° = 0.13788 radian not 0.014 radian as in textbook')
diff --git a/3035/CH15/EX15.4/Ex15_4.sce b/3035/CH15/EX15.4/Ex15_4.sce
new file mode 100755
index 000000000..13c6d68ce
--- /dev/null
+++ b/3035/CH15/EX15.4/Ex15_4.sce
@@ -0,0 +1,49 @@
+
+
+// Variable Declaration
+x = 0.25        //Transient reactance(p.u)
+E = 1.0         //e.m.f of finite generator behind transient reactance(p.u)
+x_T = 0.1       //Reactance of transformer(p.u)
+x_L = 0.4       //Reactance of one line(p.u)
+P_i = 0.7       //Pre-fault power(p.u)
+
+// Calculation Section
+X_T = x+x_T+(x_L/2)                 //Transfer reactance at pre-fault state(p.u)
+P_m = E**2/X_T                      //Amplitude of power angle curve at pre-fault state(p.u)
+X_T1 = 1.45                         //Transfer reactance b/w finite generator & infinite bus at faulty state(p.u).Refer texbook problem for figure
+P_m1 = E**2/X_T1                    //Amplitude of power angle curve at faulty state(p.u)
+r1 = X_T/X_T1
+X_T2 = x+x_T+x_L                    //Transfer reactance for post fault state(p.u)
+r2 = X_T/X_T2
+P_m2 = r2*P_m
+delta_0 = asin(P_i/P_m)        //Radians
+delta_1 = asin(P_i/(r2*P_m))   //Radians
+delta_m = %pi - delta_1         //Radians
+delta_c = 0.7                       //Specified value(radians)
+
+function ans = integrand1(delta)
+    ans = r1*P_m*sin(delta)
+endfunction    
+a = intg(delta_0, delta_c,integrand1)
+
+A_acc = P_i*(delta_c-delta_0) - a 
+
+function ans = integrand2(delta)
+    ans = r2*P_m*sin(delta)
+endfunction
+    
+b = intg(delta_c, delta_m,integrand2)
+A_dec = b - P_i*(delta_m-delta_c)
+cos_delta_cr = ((delta_m-delta_0)*sin(delta_0)-r1*cos(delta_0)+r2*cos(delta_m))/(r2-r1)
+delta_cr = acos(cos_delta_cr)*180/%pi
+
+// Result Section
+if(A_acc < A_dec) then
+    printf('System is Stable')
+    stability = A_dec/A_acc
+    printf('Margin of stability , K = %.2f' ,stability)
+else
+    printf('System is not stable')
+end    
+printf('Critical clearing angle for a certain pre-fault power = %.2f°' ,delta_cr)
+printf('Critical clearing time will be known from circuit-breaker specifications')
diff --git a/3035/CH15/EX15.5/Ex15_5.sce b/3035/CH15/EX15.5/Ex15_5.sce
new file mode 100755
index 000000000..32e42b94d
--- /dev/null
+++ b/3035/CH15/EX15.5/Ex15_5.sce
@@ -0,0 +1,23 @@
+
+// Variable Declaration
+P_i = 0.75      //Pre-fault power(p.u)
+f = 50.0        //Frequency(Hz)
+H = 6.0         //Value of H for finite machine(sec)
+x_G = 0.2       //Reactance of machine(p.u)
+x_T = 0.1       //Reactance of transformer(p.u)
+x_L = 0.4       //Reactance of line(p.u)
+V = 1.0         //Voltage of infinite bus(p.u)
+E = 1.0         //e.m.f of finite generator behind transient reactance(p.u)
+
+// Calculation Section
+X_T = x_G+x_T+(x_L)                           //Transfer reactance at pre-fault state(p.u)
+P_m = E**2/X_T                                //Amplitude of power angle curve at pre-fault state(p.u)
+delta_0 = asin(P_i/P_m)                  //Radians
+delta_0a = delta_0*180/%pi
+delta_cr = acos((%pi-2*delta_0)*sin(delta_0)-cos(delta_0))
+delta_cra = delta_cr*180/%pi
+t_cr = ((delta_cra-delta_0a)*2*H/(180*f*P_i))**0.5
+
+// Result Section
+printf('Critical clearing angle for circuit breaker at bus 1 = %.2f°' ,delta_cra)
+printf('Time for circuit breaker at bus 1 ,t_cr = %.3f sec' ,t_cr)