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
|
//CHAPTER 7- SINGLE PHASE TRANSFORMER
//Example 29
disp("CHAPTER 7");
disp("EXAMPLE 29");
//VARIABLE INITIALIZATION
va=200000; //apparent power
v1=4000; //primary voltage in Volts
v2=1000; //secondary voltage in Volts
f=50;
//loads
pf=1;
eff=0.97; // at full load and at 60% of full load
nlpf=0.5; //no load pf
lpf=0.8 //lagging pf
reg=0.05; //%regulation at 0.8 pf
//
//SOLUTION
loss=(1-eff)*va/eff; //=Pc+Pcu losses
//simultaneous equation to be solved
//eq 1: Pc+Pcu=loss;
//fractipon of copper/ ohmic losses
f=(0.6)^2; // 60% of full load
//the 2nd equation is Pc+f*Pcu=loss
//now the matrix
M=[1,1;1,f];
A=[loss,loss*0.6];
Mi=inv(M);
Ans=A*inv(M);
Pc=Ans(1,1);
Pcu=Ans(1,2);
//disp(sprintf("The Pc is %f",Pc));
//disp(sprintf("The Pcu is %f",Pcu));
//LV side
R_e2=Pcu/va;
//from %reg find X_e2
phi=acos(lpf);
X_e2=(reg-R_e2*cos(phi))/sin(phi);
//in oms units
R_e2=R_e2*v2^2/va; // in ohms
X_e2=X_e2*v2^2/va; // in ohms
disp(sprintf("The Re2 is %f Ω",R_e2));
disp(sprintf("The Xe2 is %f Ω",X_e2));
//
Rc=v2^2/Pc;
Ie2=Pc/(v2*0.25);
Ic=Pc/v2;
Iphi=sqrt(Ie2^2-Ic^2);
Xphi=v2/Iphi;
disp(sprintf("The Rc is %f Ω",Rc));
disp(sprintf("The Ie2 is %f A",Ie2));
disp(sprintf("The Ic is %f A",Ic));
disp(sprintf("The Iphi is %f A",Iphi));
disp(sprintf("The Xphi is %f Ω",Xphi));
disp(" ");
//
//END
|
