From 7f60ea012dd2524dae921a2a35adbf7ef21f2bb6 Mon Sep 17 00:00:00 2001 From: prashantsinalkar Date: Tue, 10 Oct 2017 12:27:19 +0530 Subject: initial commit / add all books --- 3574/CH5/EX5.11/EX5_11.png | Bin 0 -> 179198 bytes 3574/CH5/EX5.11/EX5_11.sce | 51 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 51 insertions(+) create mode 100644 3574/CH5/EX5.11/EX5_11.png create mode 100644 3574/CH5/EX5.11/EX5_11.sce (limited to '3574/CH5/EX5.11') diff --git a/3574/CH5/EX5.11/EX5_11.png b/3574/CH5/EX5.11/EX5_11.png new file mode 100644 index 000000000..5691fd419 Binary files /dev/null and b/3574/CH5/EX5.11/EX5_11.png differ diff --git a/3574/CH5/EX5.11/EX5_11.sce b/3574/CH5/EX5.11/EX5_11.sce new file mode 100644 index 000000000..1cdd036a7 --- /dev/null +++ b/3574/CH5/EX5.11/EX5_11.sce @@ -0,0 +1,51 @@ +// Example 5.11 +// Determine (a) Rotor frequency (b) Slip at which TDmax occurs (c) Rotor speed +// at 1/2 rated torque load (d) Required rheostat resistance (e) Rated torque +// Page No. 201 + +clc; +clear; +close; + +// Given data +S=0.0159; // Slip +Fbr=50; // Rated frequency +R1=0.00536; // Motor resistance +R2=0.00613; +X1=0.0383; // Motor reactance +X2=0.0383; +Rrhe=0; // Initial rheostat resistance +P=4; // Number of poles +NR=1000; // Rated speed +s1=0.0159; // Slip of rheostat +a=2; // Stator to rotor turns ratio +hp=400; // Motor horsepower + +// (a) Rotor frequency +fr=S*Fbr; + +// (b) Slip at which TDmax occurs +Stdmax=(R2+Rrhe)/(sqrt(R1^2+(X1+X2)^2)); + +// (c) Rotor speed at 1/2 rated torque load +s=S*(0.5)*(R2/R2); // Rotor speed at 1/2 rated torque +ns=120*Fbr/P; +nr=ns*(1-s); // Rotor speed + +// (d) Required rheostat resistance +s2=(ns-NR)/ns; +Rrhe2=((s2/s1)*(1/0.5)*(R2+Rrhe))-R2; // rheostat resistance +Rrheostat=Rrhe2/a^2; + +// (e) Rated torque +nr1=ns*(1-s1); // Rated speed +T=hp*5252/nr1; + + + +// Display result on command window +printf("\n Rotor frequency = %0.3f Hz",fr); +printf("\n Slip at which TDmax occurs = %0.4f ",Stdmax); +printf("\n Rotor speed at 1/2 rated torque = %0.0f r/min",nr); +printf("\n Required rheostat resistance = %0.4f Ohm/phase",Rrheostat); +printf("\n Rated torque = %0.0f lb-ft",T); -- cgit