Here are the answers to the quiz questions: 1. a 2. c 3. c 4. b 5. c

2. Presented To
Engr. Tuheed Ur Rehman
Presented By
Muhammad Faheem 2013-EE-04
M. Waleed Sattar Khan 2013-EE-24
M. Ehtisham ul Haq 2013-EE-36
Saqib Sarmad 2013-EE-52

3. Power Losses in MEPCO

4. FESCOFESCO GEPCOGEPCO HESCOHESCO IESCOIESCO LESCOLESCO PESCOPESCO QESCOQESCO SEPCOSEPCO
An Overview of Power System of Pakistan
13
MEPCOMEPCO
Circle
DivisionDivision
Sub-DivisionSub-Division
WAPDA
(hydro)
GENCOs
2
IPPs
DISCOs
NTDC

5. MEPCO Overview
MEPCOMEPCO
Rahim Yar KhanRahim Yar Khan
MuzzafargarhMuzzafargarh

6. MEPCO Voltage Levels
• 132 kv
• 66 kv
• 33 kv
Transmission Voltages
• 11 kv
• 400 v
• 230 v
Distribution Voltages
1 2

7. Introduction
• Power generated in power stations pass through
large & complex networks and reaches at the end
users.
Consumed
Units
Generated
Units
+ LOSSES

8. Power Losses
• This difference in the generated units and the units
that are actually consumed at the user end is
termed as Power Losses.

9. 1
2
3
Types
Types of Power Losses
•Technical
Losses
•Non Technical
Losses
•Administrative
Losses

10. Technical Losses

11. Technical Losses
• The technical losses are due to energy dissipated in
– Conductors
– Transformer
– Sub- transmission Line
– Distribution Line
• Technical losses of MEPCO are normally 3-5%, and
directly depend on the network characteristics and
the mode of operation.

12. Continued
• The major amount of losses in a power system is
in primary and secondary distribution lines.
While transmission accounts for only about 30%
of the total losses
• Therefore the primary and secondary distribution
systems must be properly planned to ensure
within limits.

14. Fixed Technical Losses
• Fixed losses do not vary according to current.
These losses take the form of heat and noise
and occur as long as a transformer is
energized.
• Between 1/4 and 1/3 of technical losses on
distribution networks are fixed losses.

15. Continued
Fixed losses on a network can be influenced in the
ways set out below.
•Corona Losses
•Open-circuit Losses(Transformer losses at no load)
•Losses caused by continuous load of measuring
elements
•Losses caused by continuous load of control
elements

16. Corona Loss
• There is a power loss due to the formation of
corona that affects the transmission efficiency of
the lines.
• This power loss is affected by both atmospheric and
line conditions.
• Power loss due to corona under healthy condition is
given by

17. Continued
• Power loss due to corona under healthy condition is
given by

18. Open-circuit Losses
• No load losses are the losses which occurred at
core of transformer, hence called core losses.
• These Losses are of constant value at constant
voltage and do not depend upon the load current.
• These are of two types
 Eddy current loss
 hysteresis loss

19. Eddy Current Loss

20. Hysteresis Loss

21. Variable Technical losses
• Variable losses vary with the amount of electricity
distributed and are, more precisely, proportional
to the square of the current.
• Consequently, a 1% increase in current leads to an
increase in losses of more than 1%.
• Between 2/3 and 3/4 of technical (or physical)
losses on distribution networks are variable
Losses.

22. Continued
• The major variable technical loss is the
– Power loss in transmission lines
– Short Circuit Losses

23. Main Reasons for Technical
Losses

24. • In practically 11 KV and 400 volts lines exist, in rural
areas are extended over long distances to feed loads
scattered over large areas.
• Thus the primary and secondary distributions lines in
rural areas are largely radial laid usually extend over
long distances.
• This results in high line resistance and therefore high
I2
R losses in the line
Lengthy Distribution lines

25. • The size of the conductors should be selected on
the basis of KVA x Km capacity of standard
conductor for a required voltage regulation but
rural loads are usually scattered and generally fed
by radial feeders.
• The conductor size of these feeders should be
adequate to lower losses.
Inadequate Size of Conductors of Distribution lines

26. • Distribution Transformers are not located at Load
center on the Secondary Distribution System.
• In many cases, Distribution Transformers are not
located centrally with respect to consumers.
• Consequently, the farthest consumers obtain an
extremity low voltage even though a good voltage
levels maintained at the transformers secondary.
Installation of Distribution transformers away from load centers

27. • In most LT distribution circuits normally the Power Factor
ranges from 0.65 to 0.75. A low Power Factor contributes
towards high distribution losses.
• For a given load, if the Power Factor is low, the current drawn
in high And the losses proportional to square of the current will
be more. Thus, line losses owing to the poor PF can be
reduced by improving the Power Factor. This can be done by
application of shunt capacitors.
• Shunt capacitors can be connected either in secondary side (11
KV side) of the 33/11 KV power transformers or at various point
of Distribution Line.
Low Power Factor in distribution system

28. Continued
• This again leads to higher line losses.
• The reason for the line losses increasing as a result
of decreased voltage at the consumers end.
• Therefore in order to reduce the voltage drop in
the line to the farthest consumers, the distribution
transformer should be located at the load center to
keep voltage drop within permissible limits.

29. • Bad Workmanship contributes significantly
role towards increasing distribution losses.
• Joints are a source of power loss. Therefore
the number of joints should be kept to a
minimum. Proper jointing techniques should
be used to ensure firm connections.
• Connections to the transformer bushing-stem,
drop out fuse, isolator, and LT switch etc.
should be periodically inspected and proper
pressure maintained to avoid sparking and
heating of contacts.
Bad Workmanship

30. • Power consumption of Customer varies throughout
the day and over seasons.
• Residential customers generally draw their highest
power demand in the evening hours.
• Same commercial customer load generally peak in
the early afternoon.
• Because current level (hence, load) is the primary
driver in distribution power losses, keeping power
consumption more level throughout the day will lower
peak power loss and overall energy losses. Load
variation is Called load factor and It varies from 0 to
1.
Load Factor Effect on Losses

31. Switching off transformers
• One method of reducing fixed losses is to switch off
transformers in periods of low demand.
• If two transformers of a certain size are required at
a substation during peak periods, only one might be
required during times of low demand so that the
other transformer might be switched off in order to
reduce fixed losses.

33. Thermography

41. Non Technical Losses

42. Non Technical Losses
• Non-technical losses are due to human
manipulation or errors and are therefore
external to the power systems.
• These losses are very difficult to measure or
quantify. They refer to losses that occur
independently of technical losses in the power
system.

43. Non Technical Losses
• Non-technical losses can also be viewed as
undetected load; customers that the utilities
don’t know exist.
• When an undetected load is attached to the
system, the actual losses increase while the
losses expected by the utilities will remain the
same

44. Causes of Losses
Two main reasons of such losses are:
•1-Component breakdown
System poor Maintenance
•2-Electricity theft
Meter related problems
Billing Problems
Un metered/flat rate supplies

45. Component Breakdown
• Losses incurred by equipment breakdown are include
losses from equipment struck by lightning, equipment
damaged by time and poor maintenance policies.
• Most power companies do not allow equipment to
breakdown in such a way and virtually all companies
maintain some form of maintenance policies.
• Equipment failures due to natural abuses like snow and
wind are also rare, for equipment is selected and
infrastructure designed with local weather and natural
phenomena considered.

46. Continued…
• Non Technical losses in Distribution system
include mainly electricity theft, calculation
errors and accounting mistakes., but also
losses due to poor equipment maintenance

47. Line Breakage

48. Faulty Insulators

49. Tree Trimming

50. Continued…

51. Schematic Diagram

52. Birds On Phase Lines
• If the bird would touch the ground while
sitting on the wire or flap its wings and touch
another electric wire with a different voltage,
then it would get shocked and likely die by
electrocution.
• Birds with high impedance would surely get
shocked and hanged over there and power
continuously dissipated through them.

53. Birds On Phase Lines

54. Electricity theft
• Theft of electricity is now a day’s becoming the
major issue of non technical losses of MEPCO. It has
various forms and causes
• illegal line tapping; (tampering with meters).
• illegal line diversions; theft by bypassing meters or
otherwise making illegal connections.
• Inadequacies and inaccuracies of meter reading.

55. Continued…
• Arranging billing irregularities with the help of
internal employees, such as making out lower bills
and adjusting decimal point position on bills.
• Non-payment of electricity bills.
• Inaccurate estimation of non-metered supplies, e.g.
public lightning, agricultural consumption, rail
traction etc. In efficiency of business and
technology
• management systems.

56. Major Ways of Theft
• There are two main categories for methods of
electricity theft:
I. Tampering with a registered load’s meter in order
to reduce the size of the bill the utility charges that
load.
II.Directly connecting an unregistered load to a power
line.

57. Meter Related Problems
• Meter bypass/ tamper
• “U- TOUCH”
• Magnet Tempering
• High meter position
• Faulty meter
• Meter ratings
• Over aged meters
• Incorrect C.T. multiplying factor

58. Tempering Techniques

59. U-Touch

60. Magnetic Tempering
• In electronic meters, there are transformers(CT, PT
or both) inside the electronic meter, placement of a
magnet as close to this transformer as possible
could cause over fluxing every half a cycle, this
could cause a diode like affect in the meter
electronics, and if the electronics are designed to
eliminate harmonics for calculating energy usage,
then the magnet has let this person pay less for
electricity, i.e. steal electricity.

63. Billing Problems
• Wrong classification
• Customers with zero readings
• Under clocked meter readings

64. Under Clocking
• Decreasing a component’s clock rate causes it
to perform less operations per second is called
Under Clocking or Down Clocking .
• It causes the disk of the energy meter to
revolve slowly than its normal rate of moving.
• It can be done in so many ways. For instance
Making holes inside the meter etc

65. Zero Readings

66. Un metered/flat rate supplies
• Under estimation
• Unpaid bills
• Using Hooks

68. How to overcome losses in
Distribution System?

69. Why should losses be minimized

70. Why should the losses be minimized?
• Technical losses represent an economic loss
for the country.
• Non-technical losses represent an avoidable
financial loss for the utility.

71. Savings from reductions in losses

72. MEPCO Losses

73. MEPCO losses
• Lets have a look at the MEPCO circles losses
in:
two years comparison
two months comparison

74. MEPCO Losses comparison between 7/15-3/16 and 7/14-3/15

75. 9 months MEPCO Losses from 07/2015 to 03/2016

76. 9 months MEPCO percentage Losses from 07/2015 to 03/2016

77. MEPCO Total Losses from 07/2015 to 03/2016

78. Circles losses decrease from 7/15-3/16 to 7/14-3/15

79. Total MEPCO Losses decrease from 7/15-3/16 to 7/14-3/15

80. MEPCO percentage recovery of 03/2016

81. MEPCO Circles March,16 Billing

82. MEPCO Circles March,16 Collection

83. MEPCO Circles Percentage Loss

84. MEPCO 1 month Losses of 03/2016 and 03/2015

85. MEPCO Losses in 03/2016

86. MEPCO Losses in 03/2016

87. MEPCO percentage Losses in 03/2016

88. MEPCO %Losses comparison b/w 03/2015 & 03/2016

89. MEPCO Losses comparison b/w 03/2015 and 03/2016

90. How can we minimize the technical losses?

91. SUGGESTIONS TO MINIMIZE TL
• Non-technical losses of the WAPDA distribution system are
extremely high. It is estimated that these losses are more
than 67% of the total distribution system losses.
• Technical loss can be reduced considerably by:
 Replacement of high capacity transformers by more number
of lower capacity transformers
 Conversion of single-phase lines to three phase lines

92. SUGGESTIONS TO MINIMIZE TL
• Location of the substation
• Use as high as voltage as is practical for the lines to limit the
current in the lines and transformer windings.
• Higher resistivity of aluminium than copper
• High efficiency transformers, which use new core types that is
amorphous metal. They cost 25 to 50% more than silicon
iron(ferromagnetic steel) transformers, they also claim 60 to
70% less losses.

93. SUGGESTIONS TO MINIMIZE TL
• Use of shunt capacitor banks.
for reactive loads a near unity
power factor (Placement).
reduced distribution system
losses by approximately 20 %.
• reducing the amount of harmonics present in the system.
Place costly filters

94. SUGGESTIONS TO MINIMIZE TL
• A final method of reducing distribution system losses is
demand-side management (DSM). reduces the system
loading, especially at peak periods

95. How can the non-technical losses be minimized?

96. SUGGESTIONS TO MINIMIZE NTL
• Non technical losses in distribution systems comprised about
2-3%, of the total system losses(12%). And 33% of total.
• Following are the non-technical strategies by which non
technical losses can be minimized or mitigated:
• Up grading of electricity meters to meet standard accuracy
must be conducted to support reduction of non technical
losses through statistical analysis

97. SUGGESTIONS TO MINIMIZE NTL
• Smart card technology
• Technical training to the
operating personnel plus
enhancing employees
loyalty

98. SUGGESTIONS TO MINIMIZE NTL
• Statistical Meter Data

99. Measures to check illegal
connections

100. Measures to check illegal connections
• Losses Reduction Gang
• Monetary Award
• Zero consumption Report

101. Continue• Consumption analysis Report
.
• Meter bypass penalty
• Meter tempering

102. Measures taken by MEPCO to reduce losses

103. Continue
• M&T
• M&S

104. Continue
• Smart meters(20 kW)
• FIA

105. Costitutions in Pakistan Law

106. Quiz on resistance
losses

107. Quiz
1. Skin effect results in
a)Reduced effective resistance but increased
effective internal reactance of the conductor
b)Increased effective resistance but reduced
effective internal reactance of. the conductor
c)Reduced effective resistance as well as
effective internal reactance
d)Increased effective resistance as well as
effective internal reactance.

108. Quiz
2. What is the effect on corona, if the spacing
between the conductors is increased?
a)Corona increases.
b)Corona is absent.
c)Corona decreases.
d)None of these.

109. Quiz
3. The effect of ice deposition on conductor is
a)Increased skin effect
b)Reduced corona losses
c)Increased weight
d)Reduced sag.

110. Quiz
4. Higher the frequency, _____________
a) Lower the corona loss.
b) Higher is the corona loss.
c)Does not effect.
d)Depends on the physical conditions.

111. Quiz
5. In a given transformer for given applied
voltage, losses which remain constant
irrespective of load changes are
a)Friction and windage losses
b)Copper losses
c)Hysteresis and eddy current losses
d)None of the above