Chapter 3 : Magnetic Materials

Example : 3.1 - Page No : 82

In [2]:
from __future__ import division
#Given data
x = 1000 # in AT/m assumed
y = 0.2 # in T assumed
a = 9.3 # area in cm**2 
# Hysteresis loss/m**3/cycle
H = a*x*y # in J/m**3/cycle
print "Hysteresis loss per cubic meter = %0.f per cycle in J/m**3/cycle " %H
f = 50 # in Hz
# Hystersis loss per cubic meter at a frequency of 50Hz 
h = H*f # in W
h = h * 10**-3 # in kW
print "Hystersis loss per cubic meter at a frequency of 50Hz = %0.f kW " %h

Hysteresis loss per cubic meter = 1860 per cycle in J/m**3/cycle 
Hystersis loss per cubic meter at a frequency of 50Hz = 93 kW 
Hysteresis loss per cubic meter = 1860 per cycle in J/m**3/cycle 
Hystersis loss per cubic meter at a frequency of 50Hz = 93 kW

Example : 3.2 - Page No : 82

In [3]:
 #Given data
a = 93 # in cm**2
x = 0.1 # in Wb/m**2
y = 50 # in AT/m
# Hysteresis loss/m**3/cycle 
H = a*x*y # in J/m**3/cycle
f = 65 # in Hz
V = 1500 # in cm**3
V = V * 10**-6 # in m**3
Ph = H*f*V # in W
print "The hysteresis loss = %0.2f W " %Ph

The hysteresis loss = 45.34 W

Example : 3.3 - Page No : 82

In [4]:
 #Given data
Eta =628 # in J/m**3
Bmax = 1.3 # in T
f = 25 # in Hz
m = 50 # in kg
rho = 7.8*10**3 # in kg/m**3
V = m/rho # in m**3
H = round(Eta*(Bmax**1.6)*f*V) # Hystersis loss in J/s
H = H * 60 *60 # Hystersis loss in J/hour
print "The Hystersis loss per hour = %0.f J " %H
h = Eta*(Bmax**1.6) # Hystersis loss/m**3/cycle
# h = x*y*area of B_H loop
x = 12.5 # in AT/m
y = 0.1 # in T
Area = h/(x*y) # in cm**2
print "The area of B-H loop = %0.f cm**2 " %Area

The Hystersis loss per hour = 550800 J 
The area of B-H loop = 764 cm**2

Example : 3.4 - Page No : 83

In [5]:
 #Given data
Pe1 = 1600 # in W
Bmax1 = 1.2 # in T
f1 = 50 # in Hz
Bmax2 = 1.5 # in T
f2 = 60 # in Hz
Pe2 = Pe1*(Bmax2/Bmax1)**2*(f2/f1)**2 # in W
print "The eddy current loss = %0.f W " %Pe2

The eddy current loss = 3600 W