Chapter 35 Current Transformers and Their Applications

Example 35_1 pgno:659

In [5]:
i=5;
r=.1;
va=i**2*r;
j=10+2*va;
print"the Ct of  VA and A may be used",j,i

the Ct of  VA and A may be used 15.0 5

Example 35_2 pgno:660

In [6]:
iS=5.;
pr=2.;
ir=2.5;
pe=pr*(iS/ir)**2
print"the burden on transformer Pe=VA",pe

the burden on transformer Pe=VA 8.0

Example 35_3 pgno:664

In [7]:
from math import sqrt
ct=2000./5.;
i=40e3;
r1=.31;
a=28.45e-4;
r2=2.;
iS=i/ct;
e=iS*(r1+r2);
f=50.;
B=e/(4.4*f*ct*a);
C=B/sqrt(2);
C=round(C*10)/10;
print"saturation magnetic field max=Wb\t rms value=Wb",B,C

saturation magnetic field max=Wb	 rms value=Wb 0.922671353251 0.7

Example 35_4 pgno:667

In [8]:
r1=.1;
r2=.4;
r=r1+r2;
i=1e3/10;
ip=100*5/50;
ie=10.;
e=45.;
y=i-ie;
per=-(ie*y-(10*i))/(i*10);
print"the percentage R.E at 1000A =percent",per*100

the percentage R.E at 1000A =percent 10.0