Best Practices in Distribution Systems Operation and Maintenanace

DRUM – TRAINING PROGRAM
A U.S. Agency for International Development (USAID)

Funded Program
BEST PRACTICES IN DISTRIBUTION

SYSTEMS
OPERATION AND MAINTENANACE
Power Systems Training Institute

Aug 28-Sep1, 06. Bangalore
Power Finance Corporation Ltd.

(A Govt. of India Undertaking)
BEST PRACTICES IN DISTRIBUTION SYSTEMS
OPERATION AND MAINTENANACE
Distribution Planning, Analysis

& Design
Sh. Venkatesh, Sr. Manager, PRDC, Bangalore

2
Contents of Presentation
 About PRDC
 Over View of the Project
 11kV feeder Analysis Methodology
 GPS- An Overview
 Case Studies
 11kV Feeder improvement schemes

About PRDC…
 PRDC is the leading power system consultant in
India and abroad.
 PRDC has provided many consulting services to
BESCOM towards the system improvement.
 PRDC has successfully completed the
distribution transformer wise energy audit in the
selected cities and towns of BESCOM.
 Currently PRDC is mapping and analyzing the
11kV rural feeders and suggesting improvement
schemes.
About PRDC…
PRDC Services to M/s KPTCL/ESCOMS…
 Grid support charges for the Jindal Vijayanagar Steel Limited, Toranagallu
 Shunt reactor requirement study for the Joint Venture Company-KPTCL
 Almatti and Upper Krishna Power project power evacuation study
 Supply of power system analysis software MiPower
 MVAR compensation study for the year 1998-99 under PFC loan
 Transmission planning and loss assessment studies for the year 1999-2012
 Season wise loss assessment for the transmission system for the year 2001-
02
 Voltage improvement and loss minimization for 11 kV feeders
 Macro level load forecasting
 Energy and Power loss computation for the HVDS system of Budhigere
feeder.
 Energy loss assessment with and without solar heaters in BESCom system.
 Energy audit of 11 kV feeders in MESCom area.
 DTC wise Energy Audit in Towns/Cities of BESCom.
Project Title…
 Feeder Wise Analysis of 11 kV Feeders
in Rural Areas of BESCOM.

 Abstract of the Results of Analysis…
 The abstract of the 11 kV feeder analysis results for

174 feeders submitted to BESCom:
Abstract of Results…
 Feasibility analysis report for the Improvement

cases:
Feasibility Report…

Scope of the Work…
Down loading the data from ETV meters provided
to 11 KV feeders at MUSS.
Survey of 11 KV line with location of the
Distribution Transformers center using GPS.
Plotting 11 KV line with Distribution Transformer
centers/conductor on the Map.
Calculation of the technical losses using the soft
ware.
Preparation of detailed project report for
improving the system and to reduce energy
losses.
Methodology…
 Creation of Digital Map is the first step in computer aided
Distribution Planning.
 The GPS Survey is ideal for utility mapping as it is fast and
accurate.
 The identified 11 kV feeder digitized map will be prepared by
walk over survey using a GPS instrument indicating the
following details.
 Type of pole.
 Span length.
 Size of conductor.
 Reference numbers of pole, etc,
Methodology…
 The following details of 11 kV feeder will be
collected from the sub-station:
 Peak load.
 Data of electrical parameters for 24 hour.
 Energy Sent-out.
 11 kV feeder digitized map will be generated
by GIS soft ware and down loading GPS data

Methodology…
 The technical losses and voltage regulation of the 11
kV feeder is computed using “MiPower” software.
 Various alternatives for improvement of the 11kV
feeder will be examined.
 The most techno-economically feasible proposal for
reduction of technical losses and improvement of
voltage regulation in the 11 kV feeder will be
evolved.

GPS Instrument…
An Overview

Salient features of GPS technology and its
relative advantages…
 GPS gives the position of location in Global Co-ordinate system
directly, whereas other types of surveys give only “X”, “Y”
coordinates of location.
 The “X”, “Y” values of location in map are dependent upon
location of origin and scale of Map, whereas identification of
location by Global Co-ordinate system i.e., latitude and
longitude is unique globally for each location and is not
dependent upon the origin or scale as in the case of Cartesian
or X, Y coordinate system.
 Survey based on GPS technology provides directly latitude and
longitude of the location of asset on the ground.
GPS- Principle of operation…
 GPS technology is based on measurement of the distance of
the position of GPS rover/ receiver on the earth from a group of
satellites in space known as satellite ranging.
 Department of Defense (DOD) of US Government operates a
group of 24 GPS satellites placed near circular orbits arranged
in a six orbital planes of 55 degree inclination at 20,200 km
above the earth’s surface, so that at least 4 satellites are
available for observations for positioning on ground/sea/air at
any time throughout the year anywhere in the world.
 These satellites complete two orbits per day, thus providing 24
hours GPS coverage for any location on the Earth and signals
are available to all users across the globe at no cost.
 A GPS rover unit is taken to every electric utility point to
determine its latitude and longitude.
 While making measurements at any place using GPS receiver
at least four satellites must be available for the reason.
 The three satellites are required to determine
three dimensional positions precisely
 the fourth one is needed to measure time of the
radio signal to travel from the satellite transmitter
to the receiver.
 The positional fix at the Asset is summed and averaged for
30 seconds
Satellite Coverage Constellation

F- 1, Chikkanahalli Feeder…
Case Study-1…
 Chikkanahalli, F-1 feeder is catered from

Avaregere, 66/11 kV sub-station of Davangere
circle.
 Technical analysis and improvement proposals
for the feeder is furnished in this case study.
Existing Diagram

 Power supply to the following villages and surrounding

areas of Avaregere O&M unit of Davangere district are
being catered from 11kV Chikkanahalli F-1 feeder.
 S R Pura
 Basapura
 Chikkanahalli.
 Lingadahalli.
 Hale Lingadahalli
 Vaddanahalli
 Reddy’s Camp …etc…

 The abstract of the DTCs connected to 11 kV, F-1,

Chikkanahalli Feeder is furnished in Table.
Abstract of the DTCs

Sl Capacity of Total capacity of the
Nos
No DTCS DTCs in kVA
1 15 kVA 7 105
2 25 kVA 4 100
3 63 kVA 24 1512
4 100 kVA 16 1600
5 250 kVA 1 250
Total 52 3567
 Conductors used in the Feeder.
11 kV Conductor/Cable details of F-1, Chikkanahalli

Feeder
Sl No Conductor type Distance (km) Distance (%)
1 Coyote 0.89 3.6
2 Rabbit 4.41 17.6
3 Weasel 12.5 49.9
4 Squirrel 7.21 28.8
5 U.G Cable 0.045 0.2
Total 25.06 100
 Trunk line length ………13.85 KM

 Spur line length ……….11.21 KM

 Monthly energy sent out & peak load.
Monthly Energy Sent out, Peak Load and Load Factor
Monthly Energy Peak load Monthly load
Sl No Month & Year
sent out in kw hr in Amps factor
1 Nov-04 465200 110 0.26
2 Dec-04 593400 170 0.34
3 Jan-05 688000 170 0.57
4 Feb-05 682400 170 0.27
5 Mar-05 740000 160 0.34
6 Apr-05 539400 170 0.43
7 May-05 636400 160 0.17
8 Jun-05 446400 145 0.27
9 Jul-05 334000 160 0.32
10 Aug-05 124000 50 0.23
11 Sep-05 191600 100 0.28
12 Oct-05 217600 110 0.24
Total 5658400 0.32
 Load shedding of 6 hours per day has been

considered for calculating the load factor.
 Energy sent out & load factor during the period of
one year from November 2004 to October 2005.
 The energy sent out through the 11 kV feeder: - 5658400
kWhr (5.66 M.U).
 The peak load recorded during the year: - 170 Amps.
 The annual load factor: - 0.32

 Load flow analysis result of the existing feeder.
The annual energy sent out from the feeder 5658400 kWhr
kW / kVAR load supplied at station end 2822/1625
Number of feeder sections over-loaded 21
Power factor of the feeder 0.8
Minimum voltage observed at tail end 8.63
Percentage voltage regulation 22%
Peak power losses in the system in Kw 522
Percentage of peak power losses 18.61%
Annual load factor 0.32
Annual loss load factor 0.17
Annual energy losses in Kwh 5,83,021
Percentage annual energy losses 10.30

 Improvement Proposals….
The energy loss in the 11 kV line during the year is

5,83,021 Kwh & percentage loss is 10.30%, which is
beyond the acceptable limits of 4.0%.
The percentage voltage regulation is 22%, which is
beyond the acceptable limits of 9.0%.
Several alternate proposals have been examined and the
following best alternate technically feasible and
economical viable proposals have been suggested to
improve the poor voltage levels & reduce the high
technical losses.
i. Conductor Replacement:
Replacement of the existing Weasel conductors by

Rabbit ACSR conductors of 11kV H.T line for a distance
of about 11 km at an estimated cost of about Rs. 9.72
lakhs.
Replacement of the existing Squirrel ACSR by Rabbit
conductors of 11 kV H.T line for a distance of about 6.7
km at an estimated cost of about Rs. 5.92 lakhs.

ii. Express Feeder:
An independent Express 11 kV Feeder with Rabbit ACSR

conductor to be drawn from the sub-station after the 11 kV
switchgear & station Isolator to Pole No P-65 for a distance 3
km by disconnecting the line between the spans P48 & P54
at an estimated cost of Rs.6.59 lakhs.
The new 11 KV line (express feeder) is proposed to cater 31
no. of DTCs with the total capacity of 2093 KVA and the
existing 11 KV line up to pole No: P-60, will cater26 DTCs
with the total capacity of 1767 KVA.
iii. Reconfiguration:
The 11 KV line to be reconfigured by constructing a

Line with Rabbit ACSR conductor from pole number P-
130 to Pole No P-112 for a distance 0.719 km (Rounded
off to 0.8 km with 10% extra for some deviations etc) at
an estimated cost of Rs.1.60 lakhs. The Existing line to
be opened between poll no P-48 and P-54.

 Cost Estimation for the proposed Improvement
Scheme….
Abstract cost estimates for the improvement works as per
proposal
Cost Estimate in Rs
Sl No Improvement Proposal Unit
Qty Proposal
Replacing the existing weasel &
1 squirrel ACSR conductors by km 17.7 15,64,253
Rabbit ACSR conductor.
Running an express feeder with
2 Rabbit ACSR conductor for km 3 6,59,247
bifurcation of loads
Construction of line for
3 km 0.8 1,60,500
Reconfiguration
Total 23,84,000
Detailed Cost Estimate of the Improvement Case…

 Load Flow Analysis Result of proposed Improvement
Scheme..
Load Flow Analysis Result for Improved Case
kW / kVAR load supplied at station end 2366/1466
Peak power losses of the system 75 kW
Percentage Peak power losses of the system 3.17%
The Reduction of peak power losses in kW 447 Kw
Percentage reduction of peak power losses 15.44%
Annual energy loss in Kwhr 83,768
Percentage of annual energy losses 1.48%
Reduction in annual energy losses in kWhr 4,99,253
% Reduction of annual energy losses 8.82%
Voltage at tail end 10.45 kV (0.95 P.U)
Percentage voltage regulation 5%

 Comparison of Load Flow Analysis Results…
Comparision between Existing & Improved Case

Parameters Existing Improved
kW / kVAR load supplied at station end 2822/1625 2366/1466
Minimum voltage observed at tail end in kV 8.63 10.45
Percentage voltage regulation 22 5

Peak power losses in the system in kW 522 75
Percentage of peak power losses 18.61 3.17

Annual energy losses in kwhr 5,83,021 83,768
Percentage annual energy losses 10.30 1.48
Single Line Diagram of Improved Feeder…

 Feasibility Analysis Report…
Techno-Economical Analysis
Annual Interest Charges 7.50%
O and M Charges 1.10%
Project Life 25 Years
Capital Investment in Rs 23,84,000
Purchase rate of energy Rs 2.52 / KWhr
Cont. Next Page…

 Feasibility Analysis Report…(cont..)
O&M Expenses at 1.1% 26,224
Present Worth of Annual Expenses in Rs 2,92,318
Present Worth of Cash Outflow in Rs 26,76,318
Annual Saving in Energy 4,99,253 kWhr
Cost of reduction of annual Energy losses Rs 12,58,118
Present Worth of cash Inflow in Rs 1,40,24,168
Net Present Worth in Rs 1,13,47,850
Net Benefit in Rs 1,37,31,850
Benefit to Cost Ratio 5.76
Pay back period 3 Years
Internal Rate of Return (IRR) 51%
Technical feasibility Feasible
Economical viability Viable
Techno-economical feasibility Feasible
Case Study-2…
F-02, Jalamangala Feeder…
Ramanagaram , 66/11 kV MUSS of

Bangalore Rural Circle.

 Analysis Report of F-02, Jalamangala Feeder …
 Technical analysis and improvement proposals for
Jalamangala 11 kV, F-02 feeder of Ramanagaram-
66/11 kV sub-station is given in this detailed report
Analysis Report of F-02, Jalamangala Feeder …
SLD of Existing F-02, Jalamangala Feeder …
SLD of Improved F-02, Jalamangala Feeder …

F- 2, Jalamangala Feeder…
 Verification from the field …
 During the analysis of Jalamanagala feeder of

Ramanagaram MUSS, we observed the tail end
voltage is only 190 Volts for a peak load of 246
Amps during January, 2005.
 To verify this we have collected the filed

measurement data at the tail end on 20th Feb-06,
at 2.00PM. The voltage at this point during the
measurement was 188 Volts for a peak load of
243 Amps.
Project Title…
 DTC wise Energy Audit in Towns/Cities
of BESCom.
BESCom had entrusted M/s PRDCL to conduct

Energy Audit of 549 Nos. of Distribution
Transformer Centers. PRDC had successfully
completes the project and the results are as
below:
Abstract of the Results …

Thank You…
Power Research & Development Consultants Pvt. Ltd.

#4, I B Main, I N Block, Rajajinagar, Bangalore 560 010
Phone: (080) 23322321
Fax: (080) 23427321
Email: prdc@vsnl.com
www.prdcinfotech.com

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DRUM – TRAINING PROGRAM

A U.S. Agency for International Development (USAID)

BEST PRACTICES IN DISTRIBUTION

Power Systems Training Institute

Power Finance Corporation Ltd.

Distribution Planning, Analysis

Sh. Venkatesh, Sr. Manager, PRDC, Bangalore

Power Finance Corporation Ltd.

Power Finance Corporation Ltd.

Power Finance Corporation Ltd.

 The abstract of the 11 kV feeder analysis results for

 Feasibility analysis report for the Improvement

Power Finance Corporation Ltd.

Power Finance Corporation Ltd.

Power Finance Corporation Ltd.

Power Finance Corporation Ltd.

Satellite Coverage Constellation

 Chikkanahalli, F-1 feeder is catered from

Power Finance Corporation Ltd.

 Power supply to the following villages and surrounding

Power Finance Corporation Ltd.

 The abstract of the DTCs connected to 11 kV, F-1,

Abstract of the DTCs

11 kV Conductor/Cable details of F-1, Chikkanahalli

 Trunk line length ………13.85 KM

Power Finance Corporation Ltd.

 Load shedding of 6 hours per day has been

Power Finance Corporation Ltd.

Number of feeder sections over-loaded 21

Power factor of the feeder 0.8

Minimum voltage observed at tail end 8.63

Percentage voltage regulation 22%

Peak power losses in the system in Kw 522

Percentage of peak power losses 18.61%

Annual load factor 0.32

Annual loss load factor 0.17

Annual energy losses in Kwh 5,83,021

Percentage annual energy losses 10.30

Power Finance Corporation Ltd.

The energy loss in the 11 kV line during the year is

Replacement of the existing Weasel conductors by

Power Finance Corporation Ltd.

ii. Express Feeder:

An independent Express 11 kV Feeder with Rabbit ACSR

The 11 KV line to be reconfigured by constructing a

Power Finance Corporation Ltd.

Detailed Cost Estimate of the Improvement Case…

Power Finance Corporation Ltd.

Comparision between Existing & Improved Case

Percentage voltage regulation 22 5

Percentage of peak power losses 18.61 3.17

Percentage annual energy losses 10.30 1.48

Single Line Diagram of Improved Feeder…

Cont. Next Page…

Power Finance Corporation Ltd.

F-02, Jalamangala Feeder…

Ramanagaram , 66/11 kV MUSS of

Power Finance Corporation Ltd.

Analysis Report of F-02, Jalamangala Feeder …