1. EE 504.69 1
DEPARTMENT OF TECHNICAL EDUCATION
ANDHRA PRADESH.
Name : P.V.KRISHNA MURTHY
Designation : Senior Lecturer
Branch : Electrical & Electronic Engg.
Institute : G.M.R. Polytechnic., Srisailam
Year/semester : v Semester
Subject : Power systems-II
Subject code : EE 504
Topic : Distribution
Sub topic : Distributors
Duration : 50 min
Teaching Aids : ppt, diagrams.
2. EE 504.69 2
RECAP
We have discussed in the last class about
•Radial distribution system
•Ring distribution system
•Comparison between radial and ring distribution system
3. EE 504.69 3
OBJECTIVES
On the completion of this topic you would be able to
know
• the classification of distributors
4. EE 504.69 4
DISTRIBUTORS
• The conductors from which numerous tapings
are taken for supplying the power to the consumers is called
distributors
5. EE 504.69 5
CLASSIFICATION OF DISTRIBUTORS
Distributor
Loading
Feeding
Concentrated loading
Uniformly distributed
loading
At unequal
voltage
Fed at one
end only
Fed at both
ends
At equal
voltage
Fed at center
Fed at any point
on ring distributor
Fig.1
6. EE 504.69 6
CLASSIFICATION BASED ON LOADING
• Concentrated loading distributors
• Uniformly distributed loading distributors
7. EE 504.69 7
CONCENTRATE LOADING OF DISTRIBUTOR
• The distributor is connected to the supply
at one or both ends and loads are taken at
different points along the length of the distributor.
8. EE 504.69 8
I1 I2 I3 I4
F
I1 r1
D
C
B
A
I2 r2 I3 r3
I4 r4
V1
CONCENTRATED LOADING OF DISTRIBUTOR
Fig.2
9. EE 504.69 9
UNIFORM DISRIBUTED LOADING DISTRIBUTOR
• The distributor is connected to the supply at one or
both ends.
• Loads are taken uniformly at different equal distant points
along the length of the distributor.
11. EE 504.69 11
CLASSIFICATION BASED ON FEEDING ENDS
• Fed at one end only
• Fed at both ends with equal voltages
• Fed at both end with un equal voltages
• Fed at centre of the distributor
• Fed at any point on the ring distributor
12. EE 504.69 12
DISTRIBUTER FED AT ONE END:
• The distributor is connected to the supply at one end and
loads are taken at different points along the length of the
distributor
• The current flowing in different sections of the distributor
away from the feeding point goes on decreasing
• The voltages across the loads away from the feeding
point goes on decreasing
• Continuity of supply is interrupted in case of fault on the
feeder
14. EE 504.69 14
DISTRIBUTOR FED AT BOTH ENDS:
• The distributor is connected to the supply mains
at both ends .
• The loads are taped-off at different points along the
length.
15. EE 504.69 15
• Continuity of supply is maintained even any fault occurs
on any section of the distributor
• Cross sectional area of the conductor required is lesser
than single fed distributor
• Continuity of supply is maintained even any fault occurs
on any fed point
ADVANTAGES
•The load voltage reaches maximum at the other feeding point
16. EE 504.69 16
• The load voltage decreases as we move away from any
feeding point
DISADVANTAGE
17. EE 504.69 17
• Middle point at minimum potential
• The distributor can be imagined to be cut into two at the
middle point
V1
L
i i i i i i i i i i i i
A B
V2
V1=V2
Distributor Fed At Both Ends With Equal Voltages
Fig.5
18. EE 504.69 18
P L/2
i
i
i
i
i
i
B
P
V2
V1 = V2
L/2
i i i i i i
A
V1
X
Distributor imagined to be cut into two equal parts
Fig.6
19. EE 504.69 19
FED AT BOTH ENDS AT DIFFERENT VOLTAGES
L
i i i i i i i i i i i i
A B
V1 V2
x
P
DX
Fig.7
20. EE 504.69 20
DISTRIBUTER FED AT THE CENTRE
The distributor is fed at The centre through supply mains
• The distributor is equivalent to two single fed
distributors with a common feeding point
• Distributor is equivalent to two single fed distributor of
length equal to half of the total length
22. EE 504.69 22
RING MAIN DISTRIBUTOR FED AT ANY POINT
• The distributor is equivalent to a straight distributor with
equal voltages.
• The distributor ring may be fed at one (or) more points
25. EE 504.69 25
QUIZ
1) Distributor can be classified into different types on the
basis of loading as
a) concentrated loading
b) Uniformly distributed loading
c)Concentrated and uniformly distributed loading
d) None of the above
26. EE 504.69 26
2) Distributor can be classified into different types on the
basis of feeding as
a) Fed at one end
b) Fed at both ends with equal voltages
c) Fed at both ends with un equal voltage
d) All of the above
QUIZ
27. EE 504.69 27
PREVIOUS EXAMINATION QUESTIONS
1) Classify the distributors according to
a) loading
b) feeding
2) Write the advantages of feeding the distributor fed at
both ends
3) Write the disadvantages of feeding the distributor fed at
one end
