MAIN

ABOUT APCPDCL

With a vision to fulfill the expectations of the Government, the Central Power Distribution Company of A.P. Limited, which came into being on 1st April 2000 as a sequel to the A.P. Electricity Reforms Act. 1998, with an objective of electricity to the people at an affordable price. With its headquarters at Hyderabad, the APCPDCL encompasses an area of seven districts viz., Anantapur, Kurnool, Mahaboobnagar, Nalgonda, Medak and Rangareddy, Catering to the power requirements of 76 million consumers.

APCPDCL has a vast infrastructure facility in its operating area with 1,338 Nos. of 33/11 KV substations, 2,039 Nos. of power transformers, 720 Nos. of 33 KV feeders, 5,257 Nos. of 11 KV feeders and around 2,46,426 Nos. of distribution transformers of various capacities.A number of new initiatives for improving the quality supply of power were introduced by APCPDCL such as:

Electronic Spot Billing.Pass Books to individual customers.Web-enabled Customer Service Centers.Tie up with e-Seva centers for bill payment.On line billing enquiry system.Tie up with e-Seva centers for bill payment.Electronic control and complaint center etc.Tims, Mats, Cat.Vidyut Sadassus, Sub-station wise Meeting.

Having electrified 6,489 villages, 5,600 general hamlets, 2,059 tribal hamlets, 12,105 Dalit wadas and 5,806 weaker sections colonies, APCPDCL is looking forward to meet many challenges with promise to deliver quality customer services through innovative programmes. The philosophy of APCPDCL is to continually striving to enhance its performance and emerge stronger by the day to offer its customers the best and value for money.The company is managed by a Board of Directors consisting of the following members: Chairman and Managing Director: Mr. M.T. Krishna Babu,IAS Director (IPC,RAC ): Mr. B. Ravindra Reddy B.E.Director (P & MM): Mr. KH. Ghulam Ahmed, B.E. Director (Commercial & Customer Services): Mr. A. Srinivasa Rao, B.E. Director (Finance): Mr. P. Rajagopal ReddyDirector (Operation - Rural): Mr. B. Veera Reddy Director (Projects & IT ): Mr. G.Raghuma Reddy Director (HRD & IR, Operations -Greater Hyderabad ): Mr. K.Venkata Narayana.

ABSTRACT

In India the losses in low voltages network constitute about 30% of total

energy, these losses occur in commercial, domestic, Industrial and agricultural sectors.

Among these agricultural sectors plays a prominent role. The existing distribution system is

low voltage distribution system. The characteristics of the system are installation of 3-

phase transformer of considerable capacity (100KV/63KVA) and extension of LV lines to

cater group of loads.

This is an agricultural demand side management project that may reduce the

technical and commercial losses by enhancing the distribution system efficiency using high

voltage distribution system i.e., high voltage line is taken as near the load as possible and

distribution transformer of appropriate capacity (16/25KV A) are installed to feed one or small

group of loads, such that the length of the LV line is minimized.

By this project in agricultural demand side area the line losses can be reduce up to

10% to 12% than the losses present in existing system. There are many advantages in

implementing HVDS system such as failures of distribution transformer, minimization of

interruptions etc. HVDS is the solution for the reduction of power losses by utilizing the same pole

structure as economic point of view and it is cost effective with low pay back period.

HIGH VOLTAGE DISTRIBUTION SYSTEM 01

CHAPTER-1

INTRODUCTION

1.1 GENERAL:

The pump loads consume nearly 30 to 40% of the total Electrical Energy

production and are growing rapidly. At the same time, the agricultural tariffs do not

provide sufficient revenue to cover the cost of production. The studies on end use

efficiency of pump sets have also indicated that the overall efficiency of the pump sets is

as low as 20% against achievable efficiency of 60% one of the main contributing factor

for low efficiency of the pump sets is the prevailing Low voltages(as low as 70% of rated

voltage) at the pump sets terminals. The low voltages have also resulted in high technical

loses in low voltage network (about 10%).Another menace of Distribution network is

rampant taping from long LV lines and extracting energy illegally. An agricultural

Demand side management program comprising enhancing Distribution system efficiency

by using 11KV High voltage Distribution System (HVDS).HVDS envisages installation

of small capacity Distribution Transformers to feed 2 or 3 pump sets with a view to

minimize LV loss extending HV lines near the load as possible by the method of clusters.

1.2 CONCEPT OF HVDS:

The loads in Rural distributions are widely dispersed and to fetch a small load

of 4 KW (5 HP) LT lines are run for long distances. For a 400 KVA load, the amperage

at 11 KV is 5 Amperes, whereas at LT it is 140 Amps. Prior to introduction of HVDS , 11

KV, 3-phase lines are run up to large sized 3-phase transformers 11KV / 433V from

which lengthy 3-phase LT Lines are run. Such a system is found not suitable for Indian

conditions, especially Rural, as voltage profiles is poor, losses are high and outages in

supply are also high.


HVDS envisages running 11 KV lines right up to a cluster 2 or 3 pump sets,

employ small sized distribution transformers (15 KVA) and extend supply to these 2 or 3

pump sets with least (or almost nil) LT lines.

1.3 SCOPE OF THE PROJECT:

The existing Distribution System is based on European practice and is called

Low Voltage Distribution System .The characteristics of this system are Insulation of 3-

phase transformer of considerable capacity (100KVA/63KVA) and extension of LV lines

to cater group of loads. This system is best suited to meet the concentrated loads of high

load density normally incident in European countries. The adoption of this system is to

feed scattered loads of low density has resulted in serious problems of low voltage high

losses, poor reliability and theft of energy.

In short, the existing LV distribution system consisting of Distribution

Transformers of high capacity (100 KVA/63KVA) is considered not suitable for feeding

dispersed loads like agriculture pump sets. Reconstructing Distribution network as high

voltage distribution system (HVDS) where HV lines are taken as near the pump sets as

possible and small capacity Distribution network problems. HVDS is the solution for

reduction of power losses by utilizing the same pole structures as economic point of view

and is cost effective with back period below 8 years.


CHAPTER II

LT DISTRIBUTION SYSTEM (LVDS)

2.1 INTRODUCTION: The existing LT distribution system is based on European practices. The characteristics of this system are installation of 3-phase transformer of considerable capacity and extension of long low voltage lines to cater a group of loads. This system is best suited to meet the concentrated loads of high load density in European countries. The adoption of this system to feed scattered loads of low density has resulted in serious problem of low voltage, high losses, poor reliability and rampant theft of energy etc. Therefore it has become necessary to convert existing distribution system as HVDS to overcome the problems faced in LVDS.

2.2 DISADVANTAGES OF EXISTING LT DISTRIBUTION SYSTEM

2.2.1 LINE LOSSES:

The long LV lines of small conductor size cause high line losses. The low voltage network energy losses alone are estimated to be 8% to 10% of total energy handled in other words, the LV network contributes to about 30% of total energy losses. The international norm for energy loss in low voltage network is 1% to 2%.Thus the energy losses of LV network are 5 to 6 international norms.

2.2.2 VOLTAGE DROP:

The voltage drop in LVDS is very high as the lines are long and conductor sizes are

small. The sample studies made in Andhra Pradesh distribution system indicated the 50% of

LV feeders have more than 10% voltage drop and another 25% have 5 -10% voltage drop . The

maximum permissible voltage drop on LV feeders is 6% in accordance with IE rules - Rule 56.


2.2.3 FAILURE OF DISTRIBUTION TRANSFORMERS:

The present failure rate of 3-phase distribution transformers is 19.91%. The major

contributing factors for this high failure rate are LT line faults and indiscriminate loading of

transformers over and about its capacity. The lengthy LT lines LVDS coupled with poor

construction standards are the cause work for large number of LT faults. Further the fault

current due to a fault at tail end of lengthy feeders may not be adequate enough to cause

protective device operation and it reflects as load on the network. Thus these faults cause

frequent failure of transformers. The overloading of transformers could not be effectively

checked, as it serves large number of consumers spread over a wide area.

Original 3ph 100KVA Dist. Transformer replaced 3ph 15KVA Dist. Transformer erected

with 11KV.CTPT set. under HVDS to cater 2 to 3 services


2.2.4 THEFT OF ENERGY:

Theft of energy by direct tapping of long LT lines passing through agricultural

fields in rural areas and colonies in urban areas has become a menace in recent years. It is

estimated to be as high as 25% of total number of services connected. These unauthorized

tapings are mainly responsible for over loading of the system and consequential failure of

transformers, high energy losses and high voltage drop.

2.2.5 END EQUIPMENT EFFICIENCY:

The high voltage drops in the LV network in low voltages at consumer

premises particularly agricultural pump sets. This has resulted in large scale burning of

pump set motors. It is estimated that motors are rewound once in 2 years and efficiency

of rewound motor is generally lower than that of new motor. Further efficiency of motors

is lower than rated efficiency, when operated at voltages lower Grated voltage. Thus the

end equipment efficiency is low resulting in wastage of energy.

2.2.6 VOLTAGE FLUCTUATIONS:

Due to high drop on LV lines the consumers are subjected to wide voltage

fluctuations with variation of load. All the modem electrical and electronic equipment are

sensitive to voltage variations and the consumers are forced to use stabilizers to provide

stable supply. The voltage stabilizers draw reactive power from the system causing

associated reactive power management problems on the upstream side of the power

system.


2.3 RELIABILITY:

Reliability of the Distribution System is largely dependent on the

performers. The existing Distribution Transformers are fully over loading. The over

loading is. due to non-location of transformers at load centers and extension of LT lines

haphazardly. This had resulted in poor voltage levels, high distribution losses and failure

of distribution transformers. Replacement of fail distribution transformer, consumer's

precious time in terms of unwarranted interruptions to consumers and the company's

revenue also gets effected due to non sale of power till the time the failed transformer is

replaced with healthy transformer, besides expenditure towards repairs of failed

distribution transformers.

In order to reduce the failure rate distribution transformers to meet the

reliability of supply to all categories of consumers to provide distribution transformers at

convenient load centers and to reduce the lengthy lines the present proposal covers

erection of 15KVA or 25 KVA 3-phase distribution transformers for reducing full load

copper losses.

Reliability of the distribution system is largely dependent on the

performance of the distribution transformers, distribution lines etc, occurrence of the

break down on any LT or HT feeders' consumers' precious time.

2.4 DESCRIPTION OF THE PROJECT AREA:

The project area selected is Thipparthy mandal in Nalgonda district of Andhra Pradesh

that comes under APCPDCL where the agricultural loads are concentrated more under

which 4 feeders of distribution transformers are considered which are

1. A. D. Pally feeder

2. Velugupally feeder

3. Vempati feeder

4. Thungathurthy Rural


Here we have selected A.D.Pally feeder with implementation of HVDS has done

fully. Under the A.D.Pally feeder consisting 05 Nos of 63KVA and 24Nos, of 100 KVA

transformers and 662 Nos, of agricultural services with the connected load of 2760 HP

and it having a length of LT and HT lines are 56.5 Km and 13.2 Km's. The crap pattern

under this feeder mainly consists of paddy and part of land is cultivated with horticulture.

Existing LT distribution system consist of 3-phase distribution transformer with a

capacity of 100KVA or 63KVA in rural areas, which feeds supply to all the consumers

through 3-phase 4-wire LT network.


Existing LT Distribution in A.D.Pally feeder:

THE PROBLEMS QCCURING IN THE EXISTING DISTRIBUTION SYSTEM

(PROJECT AREA) IS

Voltage drop at the consumer end as such the lines are lengthy High I2R losses as

such lines are in LVDS.

Frequent motor burn outs due to low voltage and consequent expenditure on

repairs.

Transformer failures- expenditure towards repairs and Inconvenience to the

consumers. Damage to standing crops, due Lo delay in replacement of failed

distribution transformers.

Fluctuations in voltages due to more number of consumers connected under this

transformer (say 25 to 30 consumers).

Nobody owns the transformer since everybody thinks that others will take care of

the transformer.


CHAPTER 3

HIGH VOLTAGE DISTRIBUTION SYSTEM(HVDS)

3.1 IMPORTANCE OF SWITCHING OVER TO HVDS:

HVDS is based on North American practices where 3-phase or S-ph HV

line is taken as near the load and distribution transformer of appropriate capacity either S-

ph or 3-ph are installed to feed one or a small group of loads, such that the length of the

tow voltage line is minimum or is eliminated altogether. This system is best suited to

meet the scattered loads of low density normally incident in the developing countries like

India.

The existing system in Andhra Pradesh Is based on European practices and is

called low voltage distribution system (LVDS). The adoption of this system to feed

scattered loads of low density has resulted in serious problems of low voltage, high

losses, poor reliability, rampant theft of energy etc .Therefore, it has become necessary to

convert the existing distribution system as HVDS to overcome the problems faced in

LVDS. The table shows the importance of change over to HVDS.

TABLE 3.1 Characteristics of the HVDS and LVDS system for distribution of some

quantum of power.


PARTICULARS HVDS as % of LVDS

Current

11.0

Power loss

0.85

Voltage drop

0.85

The HV line is taken as near the load as possible and a LV service cable is run

to feed loads. Thus the losses in LV network are negligible. The voltage drop for

Distribution of quantum of power is less than 1% as against that in LVDS and this ensures

proper voltage profile at all customer points. The length of the LT lines are minimum.

Further the AB cables are used for LT lines as current ratings are low. Thus the

failure of transformers due to LV line faults is eliminated. Consumer, whom it serves, as

its failures will affect their supply, will effectively prevent the loading of transformers

over above its capacity. The LT lines are virtually eliminated and even the short LT lines

required would be AB cable. This makes direct tapping of lines of a very difficult task. Each

transformer caters to 2 or 3 consumers and they can be made responsible to prevent any

unauthorized connection on the transformer.


The voltage drop for distribution of same amount of power is less than 1% as against that

in LVDS and this ensures proper voltage profile at all customer premises can be

maintained satisfactorily. This will avoid burning of motors. The LT line network is

replaced with HT network by substituting transformers of 16KVA and 25KVA supplying

3 to 4 nearest loads making LT lines as small as possible.

HT and LT Layout of HVD System in A. D. Pally feeder


The efficiency of end use equipment is also kept high, bringing in

considerable benefits by way of energy conservation. The LT lines are short and

insulated, avoiding all LT faults. The majority faults on HT line will come to the notice

of the operation immediately due to tripping of substation breaker. The reliability of HV

system can easily be improved by providing sectionalizes or auto re-closures on the line.

The failure of transformer will affect a very small number of consumers served by it.

Thus the reliability of power supply is very high.

The voltage drop on the LT line is negligible. The additional drop due to

extension of HV line of consumer premises is also negligible. Thus the voltage profile is

very stable and there will be no need to use voltage stabilizer. Further, any voltage

fluctuations occurring can be remedied by installation of automatic voltage. Summing up

it can be stated that HVDS is technically superior and provides ready solution to the

problem of distribution system.

3.2 REQUIREMENTS FOR IMPLEMENTATION OF HVDS:

Existing LT lines converted in to HV lines by replacing

LT 3-phase cross-arm by 11KV - V cross-arm.


Replacement of 3 numbers LT pin insulators with 3 number 11KV pin insulators.

Erection of additional supports wherever clearances are inadequate.

Replacement of 100KVA distribution transformer and erection of smaller

capacity three phase distribution transformers of 11 Nos. 15KVA capacities for every

2 to 3 pump sets.

Connection of existing pump sets from the newly erected 15KVA distribution

transformers with air bunched cable (ABC).


3.3 CONCEPT INVOLVED IN HVDS FOR I2R LOSSES REDUCTION:

The main concept of HVDS is to reduce the losses occurring in the distribution system.

Losses in the distribution system can be identified as

Technical losses Commercial losses

3.3.1 I2R LOSSES/COPPER LOSSES:

Copper losses come under technical losses. As the name itself indicates, these

losses depend on current (I) and resistance (R).

R which is resistance is directly proportional to length and inversely proportional

to its area.

R= L/A


Where, = specific resistivity of the material used for conductor

L = length of the conductor

A = cross- sectional area of the conductor,

Here, and L cannot be altered as they are not under our control. The only

alternative is to increase the size of the conductor used.

A study has been made in our project by increasing the size of the

conductor from 30sq.mm to 55sq.mm the loss reduction was significant. The losses have

come down from 5.3% to 3.75%. Now let us think about reducing I, i.e. current

We all know very well that for a given load, the current is determined by the formula,

I = Load / 3 V cos

Where, I = current in amps

V = voltage Is In Volts

Load in Watts.

To reduce the current we need to reduce the numerator or increase denominator. It is not possible to reduce the numerator since we don't have any control over the load or demand in the system. Hence, the other alternative is to increase the denominator. That means we have to increase V or increase cos0 (power factor). The existing power factor of almost all 11 KV feeders is in the range of 0.9 to 0.95 i.e. nearly unity. Hence, the other alternative is only to increase the voltage.


An attempt has been made to increase V up grading existing LT system to HV

system, the distribution system voltage was increased from 415 Volts to 11,000 Volts

and reducing LT line lengths.

We can call this system as "LT less system" or "HT system" or HVDS.

3.4 ADVANTAGES OF HVDS:

The registered customer will feel ownership and take responsibility and not

allow to meddle the LT network.

Prevention of unauthorized loads by the customers themselves since the

distribution transformer may fail if loaded beyond its capacity.

Failure will be minimal because of no over loading and no meddling of LT

lines.

In the event of equipment failure only 2 or 3 customers will get affected

instead of 25 to 30 customers in original system.

High quality of supply since there Is practically no voltage drop.

Less burn out of motors because of good voltage and less fluctuations.

Considerable reduction in line losses and consequent savings in power

purchase cost.

Since losses are reduced considerably, power can be supplied to additional

loads without any further investment or infrastructure.

No additional generation capacity needed for giving new loads due to

reduction in power drawls.

Accidents due to touching of snapped conductors reduced due to the fact that

the breaker trips at substation since the line is a 11 KV potential.


3.5 CONSUMER OPINION:

The motors are drawing lesser currents and hence life span of motor is increased.

The rate of motor burn outs is also reduced.

The motors running smoothly without hissing noise.

The transformer failures are almost avoided.

Theft of energy eliminated since the consumers will not allow others to pilfer from

their distribution transformer.

Interruptions have been minimized and quality of supply is assured,

Due to reliability of supply, 2 crops can be raised and can increase the

productivity.


CHAPTER-IV

COMPARTSION BETWEEN HVDS AND LVDS

4.1 BENEFITS OF HVDS OVER LVDS

4.1.1 Voltage Fluctuations:

Due to high voltage drop on LV lines the consumers are subjected to wide

voltage fluctuations with variation of load. All the modern electrical equipment is

sensitive to voltage variations and the consumers are forced to use stabilizers to

provide stable supply.

The voltage drop on the LT line is negligible. The additional drop due

to extension of HV line up to consumer premises is also negligible. Thus the voltage

profile is very stable and there will no need to use voltage stabilizer Thus voltage

fluctuations get minimized by the regulators on HV line.

4.1.2 Reliability of power supply:

The frequent faults on LT lines cause blowing off fuses at Distribution

transformers resulting in interruption of supply to the consumers. This interruption will

come to the notice unless it is reported by the affected consumers. This failure will affect

supply to large number of consumers served by it. Thus reliability of power supply is

poor in LVDS.

The LT lines are short and insulated, avoiding all LT faults. The reliability of

HV system can easily be improved by providing sectionalizes or autoreclosures on the

line. The failure of transformer will affect a very small number of consumers served by it.

Thus the reliability of power supply is very high in HVDS.


Existing LT 3Phase 4 wire line Same support with HVD System. on support.

4.1.3 End use Equipment Efficiency:

The high voltage drops in the LV network results in low voltages at customer

premises particularly agricultural pump sets. This resulted in large scale burning of pump set

motors the efficiency of motors is lower than rated voltage. Thus the end use equipment efficiency is

low resulting in wastage of energy in LVDS.

The voltage drop for distribution of same amount of power is less than 1% that of

LVDS and thus the voltages at the consumer premises can be maintained satisfactorily. This

will avoid burning of motors. Thus the end use equipment efficiency is very high in LVDS.


4.1.4 Failures of DTRS:

The major factors involved in the failure of DTRS in LVDS are LT line faults and

indiscriminate loading of transformers over and above its capacity. The over loading of

transformers could not be alternatively checked, as It serves large number of consumers spread

over a wide area. The following figure shows distribution transformer.

The length of LT lines is minimum, Further the AB cables are used for LT lines, as the

current ratings are low and as AB cable is cheaper than bare conductor at low current ratings.

Thus the failure of transformers due to UV line faults is eliminated. The loading of

transformer over and above its capacity will be effectively prevented by consumers

whom it serves, as its failure will affect their supply in HVDS.


4.1.5 Prevention of Theft Energy:

Theft of energy by direct tapping in agricultural and urban areas became a serious

problem. It is estimated that the number of direct tapping for pump sets is estimated to be as

high as 25% of total number of services connected. These unauthorized tapping are mainly

responsible for over loading of the system ant consequential failure by using LVDS.

The LT lines are virtually eliminated and even the short LT lines required will be AB

cable. This makes direct tapping of lines a very difficult task and the eliminating

unauthorized connections by using HVDS.

4.1.6 Line losses:

In LVDS, the long LV lines of small conductor size cause high line losses.

The international norm for energy loss in low voltage network is 1% to 2%. Thus the

energy loss of LV network of LVDS is 5 to 6 times the international norms. The HV line

is taken as near the load as possible and the LV service cable is used to feed loads. Thus

the LV networks are negligible in HVDS.

4.1.7 Voltage Drop:

The voltage drop in LVDS system is very high as the lines are long and

conductor sizes are small. The voltage drop for distribution of same quantum of power is

less than 1% as against that in LVDS and this ensures proper voltage profiles at all

customer points.


4.2 BENEFITS DUE TO IMPLEMENTATION OF HVDS SCHEME:

A study has been made by the CPDCL after implementing the HVDS

scheme in Nalgonda district. The study has resulted in the following benefits of HVDS

over LVDS.

The following details show the result of total benefits in the revenue form.

4.2.1 Benefits due to saving in Losses:

DTR capacity proposed

No. KVA total KVA

2907 25 72675

908 16 14528

Total 87023KVA

87.203MVA

Loss reduction per MVA - 1.12 LU

Total loss reduction - 97.67 LU

LRMC (Net Revenue) -1.83 per unit

Financial benefit due to reduction in energy loss - Rs. 178.73 Lakhs


4.2.2 Benefits due to reduction in failure rate:

Existing failure rate (actual) -12%

Total no. of transformers existing - 786 No

No. of transformers failed - 94 No

Average cost of repair of transformer -Rs 0.1 Lakhs

Cost of repairing of failed transformers - Rs 9.4 Lakhs

No. of transformers after implementing of scheme - 3.815

Expected failure rate - 1%

No. of transformers failed - 38 Average cost of repair of transformer - Rs. 0.1 Lakhs

Cost of repairing of failed transformers -Rs. 3.8 Lakhs

Saving due to reduction in failure of DTR’s - Rs. 5.7 Lakhs

4.2.3 Benefits due to reduction in peak power loss:

Loss reduction per MVA - 280.75 KW

MVA capacity of HVDS system - 87.203

Loss reduction for all transformers - 24482.242 KW

Saving/KW - Rs 3520 per KW

Total saving - Rs 861.77 Lakhs


4.2.4 Benefits due to reduction in avoidance of theft:

No. of unauthorized agricultural services - 1500

Average HP per service - 5 HP

Load factor - 0.0522 LU (for 7 hours only)

Likely consumption per service - 78.30 LU

Annual consumption to be metered of realization rate - 2.74 per unit

Revenue expected to be received -Rs. 214.54 Lakhs

Financial benefit due to avoiding the unauthorized Connections - Rs. 214.54 Lakhs

Considering all the above benefits, the total benefits in lakhs is

i Benefits due to saving in tosses -178.73

ii. Benefit due to reduction in failure rate - 5.62

iii. Benefit due to reduction in avoidance of theft - 214.54

iv. Benefits due to peak power loss reduction - 861.77

Total benefits -1260.67


Pictorial representation of line losses in both HT and LT distribution systems

4.3 A CASE STUDY

Details of a case where LVDS Is changed in to 11 KV HVDS under Rainigudem

substation A.D.Pally feeder and the results are explained below.

All the LT lines under Rainigudem sub-station A.D.Pally feeder of all 100KVA,63KVA

and 50KVA distribution transformers are replaced with high voltage distribution system

with a 185 numbers of 16KVA and 97 Nos, of 25KVA transformers are energized at the

load centers scattered all over the entire line.


Energy audit is conducted on HVDS. HV meters are provided at the feeders

output and the meters are provided though a cubical transformer (CT & PT) in place of

all 16KVA and 25KVA transformers to record the energy sent out on HVDS system.

CALCULATION OF LOSSES AFTER HVDS IMPLEMENTED:

The total energy input at the Raigiri feeder is 4, 72,000 units according to the energy recordings.

Therefore, total input energy = 4, 72,000 units

HT LOSS IN RAIGIRI FEEDER:

No. of 16KVA transformers erected = 135 Nos.

Average no of units drawn in each 16KVA DTP = 1,290 units


No. of 25KVA transformers erected = 97

Nos. Average no of units drawn by each 25KVA DTR = 1,815 units

Total no of units drawn = (no. of 16KVA DTR's Avg. no. of units drawn) + (no. of 25KVA DTR's Avg. no. of units drawn) = (185*1,290) + (97*1,815) = 4, 14,705 units

% Line losses = ((input – output)/input )*100

= ((4,72,000 – 4,14,705)/4,72,000)*100

= 12.13%

LT LINE LOSSES IN RAIGIRI FEEDER:

Total energy input at all 16KVA + 25KVA transformers = 4, 02,263.85 units

(Total units at feeder output - 3% of transformer losses)

Energy output of all agricultural services:

1) No. of 3 HP agricultural services = 102 Avg. no of units from each services = 590

Total units = 102 590

= 60,180 units


2) No. of 5 HP agricultural services = 450

Avg. no of units from each services = 723

Total units = 450 723 = 3, 25,350 units

Total energy output at all agricultural services = 60,180 + 3, 25,350

= 3, 85,530 units

% LT line losses = ((input – output)/input) x 100

= ((402263.85 - 385530)/4, 02,263.85) x 100 = 4.15%


RESULTS AND CONCLUSION

COMPARISION OF LOSSES: The losses in Low Voltage Distribution System (LVDS) calculated are 28.09% and after Implementation of High Voltage Distribution System {HVDS) the losses calculated is 16.28%. So the net reduction of losses is about 11.81 %.

Table: Comparison of losses and line lengths:

S.No. Particulars LVDS HVDS

1 Length of HT line 13.2 Km 85.7Km

2 Length of LT line 56.5Krn 25.39Km

3 No. of DTR's(50,63 and 100KVA) 25 -

4 No. of DTR's(16 KVA & 25 KVA) - 282

5 Voltage at tail end 325 volts 425 volts

6 % Line losses 28.09% 16.26%


Table showing losses in HVDS:

S.NO. Particulars Raigiri Feeder

1 No. of 16KVA DTR’S

erected

185

2 No. of 25KVA DTR’S

erected

97

3 No. of days 30

4 Input units 402263.85

5 Output units 385530

6 Losses 16733.85

7 % Line losses on LT after

HVDS implemented

4.15%

8 % Line losses on earlier

LVDS

18%

9 % Net production in line

losses

13.85%

Documents

MAIN