blob: c4442f8b257356cb8d8b32b7544df2a00d61ade6 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
|
// Electric Machinery and Transformers
// Irving L kosow
// Prentice Hall of India
// 2nd editiom
// Chapter 8: AC DYNAMO TORQUE RELATIONS - SYNCHRONOUS MOTORS
// Example 8-8
clear; clc; close; // Clear the work space and console.
// Given data from Ex.8-3a
// 3- phase Y-connected synchronous motor
P = 6 ; // No. of poles
hp = 50 ; // power rating of the synchronous motor in hp
V_L = 440 ; // Line voltage in volt
X_s = 2.4 ; // Synchronous reactance in ohm
R_a = 0.1 ; // Effective armature resistance in ohm
alpha = 20 ; // The rotor shift from the synchronous position in
// electrical degrees.
E_gp = 240 ; // Generated voltage/phase in volt when the motor is under-excited
f = 60 ; // Frequency in Hz
// Calculated values from Example 8-3a
V_p = 254 ; // Phase voltage in volt
// Calculations
// case a
// Torque developed per phase Using Eq.(8-17a)
S = 120 * f / P ; // Speed of the motor in rpm
T_p = ( 7.04 * E_gp * V_p ) / ( S*X_s) * sind(alpha);
// case b
// Total horsepower developed using part a
Horsepower = ( 3*T_p*S )/5252;
// Display the results
disp("Example 8-8 Solution : ");
printf(" \n From given and calculated data of Ex.8-3a,\n");
printf(" \n a: T_p = %.2f lb-ft \n ", T_p );
printf(" \n b: Horsepower = %.1f hp ", Horsepower );
|
