1 files changed, 22 insertions, 0 deletions
diff --git a/3760/CH4/EX4.37/Ex4_37.sce b/3760/CH4/EX4.37/Ex4_37.sce
new file mode 100644
index 000000000..574204290
--- /dev/null
+++ b/3760/CH4/EX4.37/Ex4_37.sce
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+
+clc;
+V=230;//supply voltage in volts
+Ra=0.5;//armature resistance in ohm
+N=250;//rated speed of motor
+I=100;//rated current in ampere
+//For the separately excited dc motor torque-speed characteristics is given by Tl=500-W, where W is rotational speed in rad/sec & Tl is load torque in Nm.
+//At rated load, motor counter emf is -
+Ea=V-I*Ra;
+//Ea=Km*Wr; Km = motor constant, Wr = rated motor speed in rad/sec
+Wr=(2*%pi*250)/60;//rated motor speed in rad/sec
+Km=Ea/Wr;//motor constant in V-s/rad
+//Armature current at any speed W is given by-
+Ia=(V-Ea)/Ra;// ie. Ia=(230-Km*W)/0.5
+//Motor torque, Te=Km*Ia=(Km/0.5)*(230-Km*W)
+//Under steady state, motor torque ,Te=load torque, Tl
+//Thus, (Km/0.5)*(230-Km*W)=500-10*W
+W=(((V*Km)/Ra)-500)/((Km^2/Ra)-10);//angular speed in rpm
+N_=(W*60)/(2*%pi);//Speed in rpm
+Ia_=(230-Km*W)/0.5//armature current
+printf('Steady state speed of motor is %f rpm\n.',N_);
+printf('Armature current drawn by motor at steady state is %f A.',Ia_);