blob: dad16e2390c2875076824d1bff80b312a01f36e4 (
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
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
|
// Electric Machinery and Transformers
// Irving L kosow
// Prentice Hall of India
// 2nd editiom
// Chapter 14: TRANSFORMERS
// Example 14-33
clear; clc; close; // Clear the work space and console.
// Given data
S = 20 ; // kVA rating of transformer
N_1 = 230 ; // Number of primary turns
N_2 = 20 ; // Number of secondary turns
V_1 = 230 ; // Primary voltage in volt
V_2 = 20 ; // Secondary voltage in volt
// from Fig.14-31a
// HV side SC test data
V_sc = 4.5 ; // short circuit voltage in volt
I_sc = 87 ; // short circuit current in A
P_sc = 250 ; // Power measured in W
// Calculations
// case a
V_h = V_sc ;// short circuit voltage in volt on HV side
I_h = I_sc ;// short circuit current in A on HV side
Z_eh = V_h /I_h ; // Equivalent immpedance reffered to the high side when coils are series connected
// case b
Z_el = Z_eh * (N_2/N_1)^2 ; //Equivalent immpedance reffered to the low side
// when coils are series connected
// case c
I_2_rated = (S*1000)/V_2 ; // Rated secondary current when coils are series connected
// case d
I_2_sc = S / Z_el ; // Secondary current when the coils in Fig.14-31a are
// short-circuited with rated voltage applied to the HV side
percent_overload = (I_2_sc/I_2_rated)*100 ; // percent overload
// Display the results
disp("Example 14-33 Solution : ");
printf(" \n Slight variations in answers are due to non-approximated calculations");
printf(" \n in scilab\n\n");
printf(" \n a: Equivalent immpedance reffered to the high side when coils are series connected :");
printf(" \n Z_eh = %f ohm \n ",Z_eh);
printf(" \n b: Equivalent immpedance reffered to the low side when coils are series connected :");
printf(" \n Z_el = %f ohm \n ",Z_el);
printf(" \n c: Rated secondary current when coils are series connected :");
printf(" \n I_2(rated) = %d A \n",I_2_rated);
printf(" \n d: Secondary current when the coils in Fig.14-31a are short-circuited :");
printf(" \n with rated voltage applied to the HV side :");
printf(" \n I_2(sc) = %d A \n",I_2_sc);
printf(" \n The percent overload is = %d percent",percent_overload);
|
