1 files changed, 44 insertions, 0 deletions
diff --git a/3472/CH33/EX33.3/Example33_3.sce b/3472/CH33/EX33.3/Example33_3.sce
new file mode 100644
index 000000000..a7b211b08
--- /dev/null
+++ b/3472/CH33/EX33.3/Example33_3.sce
@@ -0,0 +1,44 @@
+// A Texbook on POWER SYSTEM ENGINEERING
+// A.Chakrabarti, M.L.Soni, P.V.Gupta, U.S.Bhatnagar
+// DHANPAT RAI & Co.
+// SECOND EDITION 
+
+// PART III : SWITCHGEAR AND PROTECTION
+// CHAPTER 7: PROTECTIVE RELAYS
+
+// EXAMPLE : 7.3 :
+// Page number 596
+clear ; clc ; close ; // Clear the work space and console
+
+// Given data
+MVA = 20.0            // Transformer MVA
+overload = 30.0       // Overload of transformer(%)
+kV = 11.0             // Bus bar rating(kV)
+CT_trans = 1000.0/5   // Transformer CT
+CT_cb = 400.0/5       // Circuit breaker CT
+ps = 125.0            // Plug setting(%)
+ts = 0.3              // Time setting
+I_f = 5000.0          // Fault current(A)
+t_margin = 0.5        // Discriminative time margin(sec)
+
+// Calculations
+I_sec_fault = I_f/CT_cb                          // Secondary fault current(A)
+CT_cb_sec = 5.0                                  // Secondary turn
+PSM = I_sec_fault/(ps/100*CT_cb_sec)             // Plug setting multiplier
+t = 2.8                                          // Time against this PSM(sec). From graph E7.1 in textbook page no 595
+time_oper = t*ts                                 // Operating time of feeder relay(sec)
+I_ol = (1+(overload/100))*MVA*1000/(3**0.5*kV)   // Overload current(A)
+I_sec_T = I_ol/CT_trans                          // Secondary current(A)
+CT_T_sec = 5.0                                   // Secondary turn of transformer
+PSM_T = I_sec_T/CT_T_sec                         // Minimum plug setting multiplier of transformer
+I_sec_T1 = I_f/CT_trans                          // Secondary fault current(A)
+ps_T1 = 1.5                                      // Plug setting as per standard value
+PSM_T1 = I_sec_T1/(CT_T_sec*ps)                  // Plug setting multiplier of transformer
+t_T1 = 7.0                                       // Time against this PSM(sec). From graph E7.1 in textbook page no 595
+time_setting = (time_oper+t_margin)/t_T1         // Time setting of transformer
+
+// Results
+disp("PART III - EXAMPLE : 7.3 : SOLUTION :-")
+printf("\nOperating time of feeder relay = %.2f sec", time_oper)
+printf("\nMinimum plug setting of transformer relay, P.S > %.2f ", PSM_T)
+printf("\nTime setting of transformer = %.3f ", time_setting)