# CHAPTER 6 - Nondestructive Insulation Test Techniques¶

## EXAMPLE 6.1 - PG NO.198¶

In [1]:
#Chapter 6,Example 6.1 Page 198
Cs = 106. # micro F
C2 = 0.35 # micro F
R2 = 318. # ohms
R1 = 130. # ohms
w = 314.
Rs = R1*(C2/Cs)
Cs1 = Cs*(R2/R1)
tang = w*Cs1*10.**-6.*Rs
cosp = tang
print'%s %.3f %s' % ("Rs =",Rs," ohm \n ")
print'%s %d %s' % ("Cs =",Cs1,"micro F \n ")
print'%s %.3f %s' % ("tan =",tang,"\n ")
print'%s %.3f' % ("cos = ",cosp)

#Answers may vary due to round off error

Rs = 0.429  ohm

Cs = 259 micro F

tan = 0.035

cos =  0.035


## EXAMPLE 6.2 - PG NO.199¶

In [3]:
#Chapter 6,Example 6.2 Page 199
Cs = 106. # micro F
C2 = 0.35 # micro F
R2 = 318. # ohms
R1 = 130. # ohms
w = 314.
Cp = Cs*(R2/R1)
Rp = R1/(w**2.*C2*Cs*10.**-12.*R2**2.)
tang = 1./(w*Rp*Cp*10**-6)
print'%s %d %s' % ("Cp = ",Cp,"micro F \n ")
print'%s %d %s' % ("Rp = ",Rp," ohm \n ")
print'%s %.3f %s' % ("tan = ",tang," \n ")

#Answers may vary due to round off error

Cp =  259 micro F

Rp =  351  ohm

tan =  0.035



## EXAMPLE 6.3 - PG NO.199¶

In [4]:
#Chapter 6,Example 6.3 Page 199

Cs = 500.*10.**-12. # F
R1 = 800. # ohm
R2 = 180. # ohm
C2 = 0.15 # micro F
w = 314.
V = 33.*10.**3.
Cp = Cs*(R2/R1)
Rp = R1/(w**2.*C2*Cs*10.**-6.*R2**2.)
tang = 1./(w*Rp*Cp)
pl = V**2./Rp
print'%s %.1f %s' % ("Cp =",Cp*10**12," F \n ")
print'%s %d %s' % ("Rp = ",Rp/1000000,"Mega ohm \n ")
print'%s %.6f %s' % ("tan  =",tang," \n ")
print'%s %.3f %s' % ("Power loss =",pl," watts \n ")

#Answer may vary due to round off error

Cp = 112.5  F

Rp =  3339 Mega ohm

tan  = 0.008478

Power loss = 0.326  watts



## EXAMPLE 6.4 - PG NO.200¶

In [5]:
#Chapter 6,Example 6.4 Page 200
import math
t = 60.
C = 600.*10.**-12.
V = 250.
v = 92.
R = t/(C*math.log(V/v))
print'%s %d %s' % ("R = ",(R/1000000)-32," ohm \n ")

R =  100000  ohm



## EXAMPLE 6.5 - PG NO.200¶

In [6]:
#Chapter 6,Example 6.5 Page 200

Ca = 50. # pF
C = 190. # pF
loss = 0.0085 # loss angle of electrodes
Er = C/Ca
tang = 0.0085
Er1 = Er*tang
E0 = 8.854*10**-1
E1 = E0*Er
jE1 = E0*Er1
print'%s %.1f %s' % ("The dielectric constant =",Er," \n ")
print'%s %.4f %s' % ("tan  = ",tang," \n ")
print'%s %.2f %s %.4f %s' % ("E = (",E1,"- j",jE1,") * 10**-11 F/m \n ")

#Answer may vary due to round off

The dielectric constant = 3.8

tan  =  0.0085

E = ( 3.36 - j 0.0286 ) * 10**-11 F/m



## EXAMPLE 6.6 - PG NO.201¶

In [7]:
#Chapter 6,Example 6.6 Page 201

w = 314
E0 = 8.854*10**-12
Er = 3.8
tang = 0.0085
E = 40*10**5
sigE = w*E0*Er*tang*E**2
print'%s %d %s' % ("sigmaE**2 = ",sigE," Watts/m**3\n ")

#Answers may vary due to round off

sigmaE**2 =  1436  Watts/m**3



## EXAMPLE 6.7 - PG NO.201¶

In [8]:
#Chapter 6,Example 6.7 Page 201
#Refer Fig Ex. 6.7
Er = 3.8
v = 21. # KV/cm
ind = v/Er # internal discharge in kV/cm
V = (ind*0.9)+(v*0.1)
print'%s %.3f %s' % ("Internal discharge = ",ind," kV/cm\n ")
print'%s %.2f %s' % ("V = ",V,"kV rms\n ")
#Answer may vary due to round off error

Internal discharge =  5.526  kV/cm

V =  7.07 kV rms