Minimization Of Losses In Power System

Minimization Of Losses In Power System
Rajendra H.Madhavi , Aniket V. Sangade
Department of Electrical Engineering, Dr.Babasaheb Ambedkar Technological University,Lonere
[email protected] , [email protected]
AbstractThe purpose of this paper is to study the various types of Losses in power system and how it can be
minimized to the appropriate level. Availability of electric power has been the most powerful vehicle
for facilitating industrial, economic and social development of any nation . The power of electric is
transmitted by means of transmission line which deliver bulk power from generating station to load
centers and consumers. For electric power to get to the final consumers in proper form and quality,
losses along the lines must be reduced to the barest minimum. Power system losses are mainly two
types that is Technical losses & Non-technical losses[NTL]. In this paper we study the reasons behind
the losses. Also study of technical losses and deep study of non-technical losses. After that we see the
minimization techniques of power system losses.
Index Term: Electric power, Technical losses, Non-Technical losses, Electricity theft.
I.
INTRODUCTION
Electrical energy is generated at power stations which are usually located far away from load centers. Thus, a
network of conductors between the consumers and power stations is required in order to harness the power
generated. This network of conductors may be divided into two main components, namely, the distribution
system and the transmission system. Accurate knowledge of power losses on transmission lines and there is
a critical component for efficient flow of power in an electrical network. Power losses result in lower power
availability to final consumers. Hence, adequate measures need to be taken to reduce power losses to the
barest minimum Power plants' planning in a way to meet the power network load demand is one of the most
important and essential issues in power systems. Since transmission lines connect substation and generating
plants in power network, the analysis, computation and reduction of transmission losses in these networks
are of great concern to engineers and scientists. Basically, losses in electrical power system can be identified
as those losses caused by internal factors known as Technical losses and those cause by external factors are
called non-technical losses. The phenomenon of hissing noise, violet glow and production of ozone gas in an
overhead transmission line is known as corona. Copper loss is the term referred to the energy which is
dissipated by the resistance in the wire used to wind a coil in electrical devices such as transformer, motors,
and generators and in transmission lines. Copper losses occur due to the flow of currents in the conductors.
Generally, system losses increase the operating cost of electric utilities and consequently result in high cost
of electricity. However, losses transmission system could be achieved by installing generating stations near
the load centers. Losses occur at all level, from generation though transmission and distribution, to the
consumers and the meters. Non-Technical losses mainly electricity theft is a serious problem for utility
companies as they are under threat of survival because of these incurring economic losses. We know that
some utility companies in developing countries are losing about 10 to 30 percent of their total revenue,
which shows that they could not invest on measures to reduce the electricity theft. These economic losses
affect the utility company’s interest in development of the devices in view of improving the quality of supply
or for electrification process.
In this paper we see the minimization process of NTI.
II. TECHNICAL LOSSES
Technical losses in power systems are caused by the physical properties of the components of power
systems. The most obvious examples are the power dissipated in transmission lines and transformers due to
their internal electrical resistance. Technical losses are easy to simulate and calculate; computation tools for
calculating power flow, losses, and equipment status in power systems have been developed for some time.
Improvements in information technology and data acquisition have also made the calculations and
verifications easier. Technical losses are naturally occurring losses (caused by action internal to the power
system) and consist mainly of power dissipation in electrical system component such as transmission lines,
power transformers, measurement system, etc. Technical losses are possible to compute and control,
provided the power system in question consists of known quantities of loads. Technical losses occur during
transmission and distribution and involve substation, transformer, and line related losses. These include
resistive losses of the primary feeders, the distribution transformer losses (resistive loses in windings and
the core losses), resistive losses in secondary network, resistive losses in service drops and losses in kWh
meter. Losses are inherent to the distribution of electricity and cannot be eliminated. Technical losses are
due to current flowing in the electrical network and generate the following types of losses:
(i) Copper losses those are due to I2R losses that are inherent in all inductors because of the finite resistance
of conductors
(ii) Dielectric losses that are losses that result from the heating effect on the dielectric material between
conductors Technical losses are possible to compute and control, provided the power system in question
consists of known quantities of loads.
The following are the causes of technical losses:
(i) Harmonics distortion
(ii) Improper earthling at consumer end
(iii) Long single phase lines
(iv) Unbalanced loading
(v) Losses due to overloading and low voltage
(vi) Losses due to poor standard of equipment’s.
III. NON TECHNICAL LOSSES
Non-Technical losses, on the other hand, are caused by actions external to the power system or are caused by
loads and condition that the Technical losses computation failed to take into account. Non- Technical losses
are more difficult to measure because these losses are often unaccounted for by the system operators and
thus have no recorded information. Nontechnical losses (NTL), on the other hand, occur as a result of theft,
metering inaccuracies and unmetered energy. NTLs, by contrast, relate mainly to power theft in one form or
another. Theft of power is energy delivered to customers that is not measured by the energy meter for the
customer. This can happen as a result of meter tampering or by bypassing the meter. Losses due to metering
inaccuracies are defined as the difference between the amount of energy actually delivered through the
meters and the amount registered by the meters. Generation, transmission and distribution of electrical
energy involve many operational losses. Whereas, losses implicated in generation can be technically defined,
but T&D losses cannot be precisely quantified with the sending end information. This illustrates the
involvement of nontechnical parameters in T&D of electricity. Overall technical losses occur naturally and
are caused because of power dissipation in transmission lines, transformers, and other power system
components. Technical losses in T&D are computed with the information about total load and the total
energy billed .NTL cannot be precisely computed, but can be estimated from the difference between the total
energy supplied to the customers and the total energy billed. NTL are caused by the factors external to the
power system. In many developing countries, NTL are a serious concern for utility companies as they
account to about 10 to 40% of their total generation capacity. Data regarding NTL is uncertain and it is very
difficult to analyze theft in terms of actions that cause these losses. Electricity theft forms a major chunk of
the NTL. Electricity theft includes bypassing, tampering with the energy meter and other physical methods to
evade payment . Illegal tapping of electricity from the feeder and tampering with the meter are the most
identified and accounted ways of theft. Electricity theft can also be defined as, using electricity from the
utility company without a contract or valid obligation to alter its measurement is called electricity theft .
The most probable causes of NTL are:
(i) Tampering with meters to ensure the meter recorded a lower consumption reading
(ii) Errors in technical losses computation
(iii) Tapping (hooking) on LT lines
(iv) Arranging false readings by bribing meter readers
(v) Stealing by bypassing the meter or otherwise makingillegal connections
(vi) By just ignoring unpaid bills
(vii) Faulty energy meters or un-metered supply
(viii) Errors and delay in meter reading and billing
(ix) Non-payment by customers.
IV. SOURCESS OF LOSSES
A. Uncertainty
The term “uncertainty” is the difference between a measured estimated, or calculated value and he true
value that is sought. Uncertainty includes errors in observation and calculation. In this instance, the sources
of uncertainty are varied and include transmission capacity, generation availability, load requirements,
market forces, fuel prices, and forces of nature such as extreme weather.
B. Tariff
The rate at which electrical energy is supplied to consumers is known as tariff. Although tariff should include
the total cost of producing supplying electrical energy plus the profit, yet it can be same for all types of
consumers the tariff structure is based on a point of connection tariff system. The users of the grid are
charged for injection or outtake of electricity at a connection point in the transmission grid. The tariff level is
not dependent on the distance between generation or source of energy, and load.
C. Joints
In distribution system, network reconfiguration and capacitor control ,generally are used to reduce real
power losses and it improve voltage .Since both capacitor control and network reconfiguration belong the
complicated combinatorial optimization problems, it is hard to combine them efficiently for better
optimization result.
D. Energy audit
Energy audit as implied is auditing of billed energy consumption and how the energy is consumed by various
units, and sub-units in the installation and whether there is any wastage due to poor efficiency, higher
hydraulic or power losses etc. and identification of actions for remedy and correction. In respect of energy
conservation, various organizations are working in the field of energy conservation and have done useful
work in evolving measures for energy conservation.
E. Electricity theft
Electricity theft includes bypassing, tampering with the energy meter and other physical methods to evade
payment . Illegal tapping of electricity from the feeder and tampering with the meter are the most identified
and accounted ways of theft. Electricity theft can also be defined as, using electricity from the utility
company without a contract or valid obligation to alter its measurement is called electricity theft.
V. CURRENT SITUATION IN DEVELOPING COUNTRIES
A. South Asia
State-owned utilities are highly predominant in the region. Quite recently Pakistan privatized the Karachi
Electric Supply Company while all the other utilities remain stateowned. Poor operational and financial
performance, with total losses exceeding 30 percent, is typical, including the Karachi Electric Supply
Company. State-owned utilities are in the process of being restructured and corporatized in Bangladesh,
starting from a poor operational and inancial base. Total losses exceed 20 percent in all cases, although
figures vary among the different companies. In ndia, most of distribution activities are carried out by
utilities owned by state governments. The exceptions are eliance (former BSES) and Tata, two private
companies serving Mumbai which have always been private. While both Reliance and Tata show total losses
of about 11–12 percent,3 the performance of stateowned utilities is enerally bad, with losses exceeding 30
percent in most cases. Seven states started reform and restructuring of their power sectors in the 1990s,
involving unbundling and corporatization of state-owned utilities. Privatization of only six distribution
companies has gone forward so far and three of those have failed. The state of Orissa was the first to
unbundle its electricity companies in 1996, followed by three failed attempts at privatizing distribution
companies. Privatization of the New Delhi Vidyut Board in Information obtained from the website of the
Maharashtra Electricity Regulatory Commission (MERC), available at www.merc.org. July 2002 was an
ambitious undertaking, given its more than 4 million customers and losses greater than 50 percent of all
power purchased at the time of takeover by new private owners, Reliance and Tata. The privatized
companies have reduced total losses markedly. The case of the North Delhi Power Limited (NDPL), described
in section 4.3, is probably the most recent example of a great success in sustainable loss reduction using
state-ofthe- art management and information technology tools currently available worldwide. A successful
functional unbundling program from an operational perspective is restructuring of the Andhra Pradesh State
Electricity Board (APSEB). This utility has unbundled and corporatized the units in charge of generation,
transmission, and distribution, while maintaining state ownership of all entities. One transmission and four
distribution companies were created. They managed to reduce transmission and distribution losses from
about 38 percent in 1999 to 26 percent in 2003 and less than 20 percent in 2008—in large part through theft
control, with the utilities regularizing 2.25 million unauthorized connections.
B East Asia
Chinese state-owned provincial electric power companies generally show good operational performance, in
terms of service provided to existing customers, losses which are low, and connection of new consumers in
rural areas. Performance of some companies in the richest South-Eastern region is excellent and comments
made on the Chilean utilities are equally applicable. In the last 10 years, Vietnam has achieved impressive
results in improving operational performance of its state-owned electricity utilities and increasing
electrification rates, despite a 15 percent annual growth in demand. Losses have been drastically reduced
and service quality improved, particularly in urban areas; rural areas still need further improvement. The
Philippines has reasonably well performing private companies serving the capital and more than 100 small,
poorly performing cooperatives in main urban areas characterized by poor operational and financial
performance.
VI. MINIMIZATION OF LOSSES
In this we see the example of two companies who minimize their losses with more amount. From that we
have a idea how to minimize the power system losses. That two companies are as follows.
A. North Delhi Power Limited (NDPL)
North Delhi Power Limited (NDPL) was founded on July 1, 2002 through public/private partnership
framework as a 51:49 joint venture between Tata Power and Government of Delhi. NDPL distributes
electricity in the north and northwest parts of Delhi and serves a population of about 5 million people spread
across 510 square kilometers (km2). It has a registered consumer base of about 1 million, a peak load of
1,180 million volt-amperes, and an annual energy consumption of about 6,200 giga watt-hours. Six years into
its inception, NDPL has achieved impressive results in reducing total losses, moving from 53 percent at
takeover in July 2002 to 18.5 percent at the end of 2008 and 15 percent in April 2009. According to
information published on the company’s website (www.ndplonline.com) and data obtained in personal
meetings with Commercial Direction, the various measures taken to achieve this loss reduction include the
following:
1. Implementation of advanced metering infrastructure (AMI) for metering, reading, and monitoring
consumption of all consumers with demand of 15 kilowatts and above, who represent 30,000 users, or 3
percent of total, but contribute to almost 60 percent of the revenue.
2. Installation of medium voltage distribution (MVD) networks in theft-prone areas, with direct connection of
each consumer to the low voltage terminal of the supply transformer
3. Replacement of old erroneous electromechanical meters with accurate electronic meters
4 .Energy audits up to the distribution transformers (medium to low voltage) level
5. Aggressive enforcement activities with scientific inputs and analysis
6. Public participation in controlling theft through the concept of “social audit”
7.Collaboration with non-governmental organizations for creating awareness in slums regarding the dangers
associated with direct tapping of electricity from live wires.
NDPL’s Commercial Direction considers implementation of AMI for large consumers the reason explaining
90 percent or more of the quantitative results obtained, as the other measures are at less advanced
implementation stages. In addition, the company is taking advantage of the application of a performancebased multiyear tariff regulatory regime. Performance targets (including allowance on total losses) are set
by the regulator for a four-year tariff period. If the company meets or surpasses those targets, it is allowed to
keep the surplus profits (additional revenues and reduced costs) until the next tariff period. NDPL is
operating consistently below the allowed total losses. Thus, the difference between the allowed revenue
(based on the performance target) and the actual amount of energy purchased is retained by the company as
an additional profit. For the next tariff period, the regulator will set new targets for losses starting from the
values actually achieved by NDPL. The performance-based, multi-year tariff regulatory regime has shown to
provide the right incentives to the regulated companies to improve their performance.
B. Privatized distribution companies in Central America: DELSUR in El Salvador
There are five major distribution companies operating in El Salvador, which were privatized at the end of the
1990s. Four of them are owned by the U.S. group AES, while the fifth (DELSUR) was purchased by the U.S.
group PPL Global Inc. for about US$180 million in 1998. At that time the company had about 194,000
customers located in the south central area of the country including a part of San Salvador, the capital city.
Five years after takeover, the number of customers served by DELSUR had reached 255,000, who consumed
about 25 percent of the country’s total electricity demand. PPL’s experience and knowhow in the utility
business significantly improved overall management and operational efficiency of DELSUR. The company
quickly moved to a customer-oriented management approach, the main actions of which included the
following:
1.Implementation of a call center operating 24 hours every day
2. Expanding or improving customer care centers throughout San Salvador to increase contact with
customers and to bemore responsive to their concerns
3. Incorporation of IT-based MIS and execution of field campaigns to develop commercial functions
(metering, billing, payment collection, customer service through call centers and at care centers), including
the construction of a new customer database incorporating historical consumption, billing and payment
records, and other relevant commercial parameters.
This enabled more efficient and transparent development of commercial functions, which led to a sustained
improvement of billing and collection rates. DELSUR reduced total losses from 15 to around 7 percent in just
five years and the loss reduction has been sustained to this day. In the two periodic tariff reviews performed
in 2002 and 2007, the national electricity and telecommunications regulator SIGET set progressively tighter
targets on total losses, which were achieved by the company in the 2002–2007 tariff period (the tariff period
beginning in 2007 runs until 2012).
VII. USEFUL SOLUTION FOR MINIMIZATION OF LOSSES
A. Measures for reducing technical losses
i). Identification of the weakest areas in the distribution system and strengthening /improving them so as to
draw the maximum benefits of the limited resources.
ii) Reducing the length of LT lines by relocation of distribution sub stations/installations of additional
distribution transformers (DTs).
iii) Installation of lower capacity distribution transformers at each consumer premises instead of cluster
formation and substitution of DTs with those having lower no load losses such as amorphous core
transformers.
iv)Installation of shunt capacitors for improvement of power factor.
v) Mapping of complete primary and secondary distribution system clearly depicting the various parameters
such as conductor size line lengths etc..
vi) Carrying out detailed distribution system studies considering the expected load development during the
next 8-10 years.
vii) Preparation of long-term plans for phased strengthening and improvement of the distribution systems
along with associated transmission system.
viii)Estimation of the financial requirements for implementation of the different phases of system
improvement works.
ix) Formulation of comprehensive system improvement schemes with detailed investment program so as to
meet system requirement for first 5 years period.
B. Employee training :
To be effective, training and management development programs need to take into account that
employees learning is based on five ideas:
(i) adults need to know why they are learning something,
(ii) adults need to be self-directed
(iii) adults bring more work-related experiences into the learning situation,
(iv) adults enter into a learning experience with a problemcentered approach to learning
(v) adults are motivated to learn by both extrinsic and intrinsic motivators.
This requires that organizations recognize that different employees will have different needs and that these
needs will change over time as these workers continue in their careers.
C. Consumer training :
(i)Shifting of energy use to off-peak hours Energy conservation
(ii)Efficient choice and utilization of electrical appliances
(iii)Standards, quality and performance
(iv)evaluation of domestic electric equipment’s Energy audit .
VIII. CONCLUSION
One of the outstanding and major problems in the transmission and distribution system is the losses .In this
paper we study the power system losses along with their types. This paper mainly focus on Technical losses
and Non-Technical losses. We see the sources of losses and present situation of developing countries
regarding with power system losses. From the brief study of different papers, books and Thesis we know the
minimization techniques of power system losses
which is helpful for not only reduce the price of electricity but also growth of our nation development. So
from this paper we conclude that the study of power system losses very necessary.
IX. ACKNOWLEDGMENT
The authors would like to thank their parents for their kind support & Mr. Rohit Ramteke for his valuable
guidance to this paper.
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