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Diffstat (limited to '3872/CH11/EX11.7/Ex11_7.sce')
-rw-r--r-- | 3872/CH11/EX11.7/Ex11_7.sce | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/3872/CH11/EX11.7/Ex11_7.sce b/3872/CH11/EX11.7/Ex11_7.sce new file mode 100644 index 000000000..82622ecee --- /dev/null +++ b/3872/CH11/EX11.7/Ex11_7.sce @@ -0,0 +1,52 @@ +//Book - Power system: Analysisi & Design 5th Edition
+//Authors - J. Duncan Glover, Mulukutla S. Sarma, and Thomas J.Overbye
+//Chapter-11 ;Example 11.7
+//Scilab Version - 6.0.0; OS - Windows
+
+clc;
+clear;
+
+function result=table(delcr) //Function to get result in table format using Euler’s method for diferent critical clearing angles
+delta=0.4179 //Initial value of delta in rad taken from example 7.6
+omega=2*%pi*60 //Initial value of omega in rad/s
+H=3 //Value of H constant in pu-s
+omegasyn=omega
+t=0;
+delt=0.02 //Step size
+result=[]; //Initialization of result table
+tc=0; //Initialization of critical clearing time
+while t<0.861 //Maximum time for Eler's method is o.86
+ result=[result;t delta omega] //Updating the result table
+ ddeltat=omega-omegasyn //Calculation of ddeltat/dt using equation 11.4.7
+ deltab=delta+ddeltat*delt //Calculation of delta_bar using equation 11.4.9
+
+ if delta<delcr //Steps to calculate accelerating power for prefault condition
+ papu=1-0.9152*sin(delta)
+ pafb=1-0.9152*sin(deltab)
+ else //Steps to calculate accelerating power for postfault condition
+ tc=tc+1;
+ papu=1-2.1353*sin(delta)
+ pafb=1-2.1353*sin(deltab)
+ end
+ if tc==1 & delcr==1.95 //Displaying result of case 1(Stable) stable with Critical clearing angle of 1.95
+ printf('The critical clearing time for case 1 is %.2f sec\n',t)
+ elseif tc==1 & delcr==2.09 //Displaying result of case 2(Unstable) stable with Critical clearing angle of 2.09
+ printf('The critical clearing time for case 2 is %.2f sec\n',t)
+ end
+ domegat=papu*omegasyn*omegasyn/(2*H*omega) //Calculation of domegat/dt using equation 11.4.8
+ omegab=omega+domegat*delt //Calculation of omega_bar using equation 11.4.10
+ ddeltab=omegab-omegasyn //Calculation of ddelta_bar/dt using equation 11.4.11
+ domegab=pafb*omegasyn*omegasyn/(2*H*omegab) //Calculation of domega_bar/dt using equation 11.4.12
+ delta=delta+(ddeltat+ddeltab)*delt/2 //Calculation of delta for change in time using equation 11.4.13
+ omega=omega+(domegat+domegab)*delt/2 //Calculation of omega for change in time using equation 11.4.14
+ t=t+delt;
+end
+endfunction
+
+case1=table(1.95) //case1 - critical clearing angle is 1.95 rad
+case2=table(2.09) //case2 - critical clearing angle is 2.09 rad
+printf(' ----------------------------- -----------------------------\n')
+printf(' CASE-1 STABLE CASE-2 UNSTABLE \n')
+printf(' ----------------------------- -----------------------------')
+disp([case1 case2],'Time(s) Delta(rad) Omega(rad/s) Time(s) Delta(rad) Omega(rad/s)')
+
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