Load Flow Analysis of 66 kV substation using ETAP Software
1 like192 views
This document summarizes a study that performed load flow analysis of a 66kV substation in India using ETAP software. The analysis found under voltages at two feeder buses. Capacitor banks were added in the model to address this. With the capacitor banks, load flow analysis showed the under voltages were overcome and losses were reduced. The study demonstrates how software can accurately model real systems and identify issues like under voltage for improvement.
![International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056
Volume: 04 Issue: 02 | Feb -2017 www.irjet.net p-ISSN: 2395-0072
© 2017, IRJET | Impact Factor value: 5.181 | ISO 9001:2008 Certified Journal | Page 770
Load Flow Analysis of 66 kV substation using ETAP Software
Kanchana Baby1, K. L. Sreekumar2
1PG student, Dept. of Electrical and Electronics, Govt. Engineering College, Barton Hill, Trivandrum, India
2 Associate Professor, Dept. of Electrical and Electronics, Govt. Engineering College, Barton Hill,Trivandrum, India
---------------------------------------------------------------------***---------------------------------------------------------------------
Abstract - Power is essentiallyrequiredforthedevelopment
of any country. To maintain the generation of electric power
at adequate level the power has to be transmitted in proper
form and quality to the consumer. This research paper deals
with the simulation of 66 kV substation in ElectricalTransient
Analyzer Program (ETAP)withdetailedloadflowanalysisand
also to overcome the problem of an under voltage. The results
are based on actual data received from 66 kV substation.
Key Words: Capacitor bank placement, demand andLosses,
Load Flow Analysis using ETAP software, need of Load Flow
Analysis, reactive power transmission, the problem of an
under voltage, voltage profile
1.INTRODUCTION
Load flow analysis using software is accurate and gives
highly reliable results. This research makes effective use of
Electrical Transient Analyzer Program (ETAP) to carry out
load flow analysis of 66 kV substation [1],[2]. The actual
ratings of Power Transformers, Circuit Breakers, Current
Transformers,Potential TransformersandIsolatingswitches
are taken and modelled accordingly in ETAP. This 66 kV
substation is located in Trivandrum, Veli under Kerala State
Electricity Board Limited (KSEB) which comprises of 3
Power Transformers, 13 Circuit Breakers, 13 Current
Transformers, 3 Potential Transformers and 6 Isolating
switches.
The major cause of almost all the major power system
disturbance is under voltage. Reactive power (Vars) cannot
be transmitted very far especially under heavy load
conditions so it must be generated close to the point of
consumption. This isbecausethedifferenceinvoltagecauses
reactive power (Vars) to flow and voltages on a power
system are only +/- 5 percent of nominal and this small
voltage difference does not cause substantial reactivepower
(Vars) to flow over long distances. So if that reactive power
(Vars) is not available at the load centre, the voltage level go
down. Chronic under voltages can cause excess wear and
tear on certain devices like motor as they will tend to run
overly hot if the voltage is low[4].
The single line diagram of the substation is simulated in
ETAP based upon actual data and it is seen that at both the
11 kV feeder buses there is under voltage. To overcome the
under voltage at both the 11 kV feeder buses capacitor bank
of suitable ratings are placed in shunt.
Section 2 is the details of the components. Section 3 is the
simulation of single line diagramof66kVsubstationinETAP
based upon practical data. Section 4 is the Load Flow
Analysis of the substation. Section 5 contains the Alert
summary report generated afterloadflowanalysis.Section6
is the load flow analysis of the substation with an
improvement to surmount the problem of under voltage.
Section 7 is the conclusion of this research work.
2. DETAILS OF COMPONENTS
TABLE 1
Component Name Rating
Power Transformer T1 10MVA
T2 8MVA
T5 8MVA
Circuit Breaker CB1-CB17 140kV/2500A
Current Transformer CT1-CT14 400/200/100/
50-1-1-1-1A
Potential Transformer PT1-PT6 66kV/√3-
110V/√3
Feeders Station Auxiliary 10A
General Hospital 190A
Karikkakom 180A
Muttathara 280A
Airport 220A
Aspirin 150A
Pettah 260A
Chakkai 160A
Aerodrome 200A
Industrial 230A](https://image.slidesharecdn.com/irjet-v4i2149-171115095623/85/Load-Flow-Analysis-of-66-kV-substation-using-ETAP-Software-1-320.jpg)
![International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056
Volume: 04 Issue: 02 | Feb -2017 www.irjet.net p-ISSN: 2395-0072
© 2017, IRJET | Impact Factor value: 5.181 | ISO 9001:2008 Certified Journal | Page 771
3. SIMULATION OF 66 KV SUBSTATION IN ETAP
Fig. 1. Simulated diagram of 66 kV substation
4 LOAD FLOW ANALYSIS
Fig. 2 shows the Load Flow Analysis of the 66 kV
substation carried outusingETAPinwhichNewton-Raphson
method [5],[6] is used and it is observed that at the Bus3and
Bus 4 there is under voltage which can be clearly seen from
Fig. 2 (a) showing the sectional view of the feeders. At Bus 2
the voltage level is 92.70% and at bus 3 he voltage level is
93.30%.
Fig. 2. Load Flow Analysis of 66 kV substation
Fig. 3. Sectional View of the Feeders
TABLE 2 shows that the real power on swing bus i.e. BUS
1 is 24.463 MW and the reactive power is 16.088 Mvar and
the power factor is 83.6% which is very low.
TABLE 2
Point kV MW Mvar %PF
Bus 2 11 10.214 6.33 81.022
Bus 3 11 19.244 11.926 86.211
TABLE 3 shows the Demand and Losses summary report
which tells us about the total demand of the system and
also about the losses that occurs in a system.
TABLE 3
Type MW Mvar
Load 32.433 20.1
Generation 32.716 24.253
Loss 0.283 4.153
5 ETAP ALERTS DURING LOAD FLOW ANALYSIS
TABLE 4 After carrying out load flow analysis using ETAP
an alert summary report is generated which tells us which
part of the system needs immediate attention and it can
be clearly seen from the Table 4 that the Bus 2 and
Bus 3 are operating at an under voltage.
TABLE 4
Device Condition Rating Operating %Operating
Bus 2 UnderVoltage 11kV 10.196 92.7
Bus 3 UnderVoltage 11kV 10.259 93.3](https://image.slidesharecdn.com/irjet-v4i2149-171115095623/85/Load-Flow-Analysis-of-66-kV-substation-using-ETAP-Software-2-320.jpg)
![International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056
Volume: 04 Issue: 02 | Feb -2017 www.irjet.net p-ISSN: 2395-0072
© 2017, IRJET | Impact Factor value: 5.181 | ISO 9001:2008 Certified Journal | Page 773
Also, they are useful in determining the system voltages
under conditions of suddenly applied or disconnectedloads.
Load flow studies determine if system voltages remain
within specifiedlimitsunder variouscontingencyconditions,
and whether equipment such as transformers and
conductors are overloaded. Load-flowstudiesareoftenused
to identify the need for additional generation, capacitive, or
inductive VAR support, or the placement of capacitors
and/or reactors to maintain systemvoltageswithinspecified
limits.
References
[1] Keith Brown, Herminio Abcede, Farookh Shokooh,
Gary Donner “Interactive Simulation of Power
Systems: ETAP applications and techniques”,
Page(s): 1930-1941,IEEE ,1990.
[2] J. Arrillaga, N.R. Watson “Computer Modelling of
Electrical Power Systems”, second edition, ISBN :
978-0-471-87249-8 , John Wiley and Sons[2001].
[3] Rohit Kapahi “Load Flow Analysis of 132 kV
substation using ETAP Software’ International
Journal of Scientific &EngineeringResearchVolume
4, Issue 2, February-2013 ISSN 2229-5518
[4] Charles Mozina, “Undervoltage Load Shedding”,
ISBN: 978-1-4244-0855-9, IEEE, Page(s): 39-54.
[5] Glenn W. Stagg and Ahmed H. El-Abiad, “Computer
Methods in Power System Analysis”, McGraw-Hill
[1968].
[6] M.A.Pai, “Computer Techniques in Power System
Analysis”, second edition, ISBN: 0-07-059363-9,
Tata McGraw Hill [2005].](https://image.slidesharecdn.com/irjet-v4i2149-171115095623/85/Load-Flow-Analysis-of-66-kV-substation-using-ETAP-Software-4-320.jpg)
Load Flow Analysis of 66 kV substation using ETAP Software
- 1. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 04 Issue: 02 | Feb -2017 www.irjet.net p-ISSN: 2395-0072 © 2017, IRJET | Impact Factor value: 5.181 | ISO 9001:2008 Certified Journal | Page 770 Load Flow Analysis of 66 kV substation using ETAP Software Kanchana Baby1, K. L. Sreekumar2 1PG student, Dept. of Electrical and Electronics, Govt. Engineering College, Barton Hill, Trivandrum, India 2 Associate Professor, Dept. of Electrical and Electronics, Govt. Engineering College, Barton Hill,Trivandrum, India ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - Power is essentiallyrequiredforthedevelopment of any country. To maintain the generation of electric power at adequate level the power has to be transmitted in proper form and quality to the consumer. This research paper deals with the simulation of 66 kV substation in ElectricalTransient Analyzer Program (ETAP)withdetailedloadflowanalysisand also to overcome the problem of an under voltage. The results are based on actual data received from 66 kV substation. Key Words: Capacitor bank placement, demand andLosses, Load Flow Analysis using ETAP software, need of Load Flow Analysis, reactive power transmission, the problem of an under voltage, voltage profile 1.INTRODUCTION Load flow analysis using software is accurate and gives highly reliable results. This research makes effective use of Electrical Transient Analyzer Program (ETAP) to carry out load flow analysis of 66 kV substation [1],[2]. The actual ratings of Power Transformers, Circuit Breakers, Current Transformers,Potential TransformersandIsolatingswitches are taken and modelled accordingly in ETAP. This 66 kV substation is located in Trivandrum, Veli under Kerala State Electricity Board Limited (KSEB) which comprises of 3 Power Transformers, 13 Circuit Breakers, 13 Current Transformers, 3 Potential Transformers and 6 Isolating switches. The major cause of almost all the major power system disturbance is under voltage. Reactive power (Vars) cannot be transmitted very far especially under heavy load conditions so it must be generated close to the point of consumption. This isbecausethedifferenceinvoltagecauses reactive power (Vars) to flow and voltages on a power system are only +/- 5 percent of nominal and this small voltage difference does not cause substantial reactivepower (Vars) to flow over long distances. So if that reactive power (Vars) is not available at the load centre, the voltage level go down. Chronic under voltages can cause excess wear and tear on certain devices like motor as they will tend to run overly hot if the voltage is low[4]. The single line diagram of the substation is simulated in ETAP based upon actual data and it is seen that at both the 11 kV feeder buses there is under voltage. To overcome the under voltage at both the 11 kV feeder buses capacitor bank of suitable ratings are placed in shunt. Section 2 is the details of the components. Section 3 is the simulation of single line diagramof66kVsubstationinETAP based upon practical data. Section 4 is the Load Flow Analysis of the substation. Section 5 contains the Alert summary report generated afterloadflowanalysis.Section6 is the load flow analysis of the substation with an improvement to surmount the problem of under voltage. Section 7 is the conclusion of this research work. 2. DETAILS OF COMPONENTS TABLE 1 Component Name Rating Power Transformer T1 10MVA T2 8MVA T5 8MVA Circuit Breaker CB1-CB17 140kV/2500A Current Transformer CT1-CT14 400/200/100/ 50-1-1-1-1A Potential Transformer PT1-PT6 66kV/√3- 110V/√3 Feeders Station Auxiliary 10A General Hospital 190A Karikkakom 180A Muttathara 280A Airport 220A Aspirin 150A Pettah 260A Chakkai 160A Aerodrome 200A Industrial 230A
- 2. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 04 Issue: 02 | Feb -2017 www.irjet.net p-ISSN: 2395-0072 © 2017, IRJET | Impact Factor value: 5.181 | ISO 9001:2008 Certified Journal | Page 771 3. SIMULATION OF 66 KV SUBSTATION IN ETAP Fig. 1. Simulated diagram of 66 kV substation 4 LOAD FLOW ANALYSIS Fig. 2 shows the Load Flow Analysis of the 66 kV substation carried outusingETAPinwhichNewton-Raphson method [5],[6] is used and it is observed that at the Bus3and Bus 4 there is under voltage which can be clearly seen from Fig. 2 (a) showing the sectional view of the feeders. At Bus 2 the voltage level is 92.70% and at bus 3 he voltage level is 93.30%. Fig. 2. Load Flow Analysis of 66 kV substation Fig. 3. Sectional View of the Feeders TABLE 2 shows that the real power on swing bus i.e. BUS 1 is 24.463 MW and the reactive power is 16.088 Mvar and the power factor is 83.6% which is very low. TABLE 2 Point kV MW Mvar %PF Bus 2 11 10.214 6.33 81.022 Bus 3 11 19.244 11.926 86.211 TABLE 3 shows the Demand and Losses summary report which tells us about the total demand of the system and also about the losses that occurs in a system. TABLE 3 Type MW Mvar Load 32.433 20.1 Generation 32.716 24.253 Loss 0.283 4.153 5 ETAP ALERTS DURING LOAD FLOW ANALYSIS TABLE 4 After carrying out load flow analysis using ETAP an alert summary report is generated which tells us which part of the system needs immediate attention and it can be clearly seen from the Table 4 that the Bus 2 and Bus 3 are operating at an under voltage. TABLE 4 Device Condition Rating Operating %Operating Bus 2 UnderVoltage 11kV 10.196 92.7 Bus 3 UnderVoltage 11kV 10.259 93.3
- 3. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 04 Issue: 02 | Feb -2017 www.irjet.net p-ISSN: 2395-0072 © 2017, IRJET | Impact Factor value: 5.181 | ISO 9001:2008 Certified Journal | Page 772 6 LOAD FLOW ANALYSIS WITH AN IMPROVEMENT TO OVERCOME THE PROBLEM OF UNDER VOLTAGE Fig. 4 The simulation of the 66 kV substation is carried out in ETAP by placing the capacitor banks in shunt with the feeders. The rating of capacitor bank 1 is 5.5 Mvar and that of capacitor bank 2 is 8 Mvar. Fig. 2 shows the load flow analysis of the substation. From Fig. 3 which shows the sectional view of the feeders it can be clearly seen that the operating voltage of Bus 2 has improved from 92.7% to 97.8% and that of Bus 3 from 93.3% (Fig.2) to 96.9%. Fig. 4. Simulated diagram of 66 kV substation using ETAP Fig. 5. Load Flow Analysis of 66 kV substation after placing capacitor banks TABLE 5 shows the load flow results and by comparing it with TABLE 2 it can be clearly seen that there is an improvement in the power factor. TABLE 5 Monitoring kV MW MVar %PF Bus 2 11 10.419 6.457 84.34 Bus 3 11 19.514 12.094 86.26 TABLE 6 shows the Demand and Losses summary report and the losses are far less as compared to the losses shown in TABLE 3. TABLE 6 Type MW Mvar Load 32.908 7.627 Generation 33.11 10.58 Loss 0.202 2.953 By comparing TABLE 7 to TABLE 4 it can clearly be seen that the problem of an under voltage at both the buses is surmounted by the placement of capacitor banks in shunt to the feeders. TABLE 7 Device Condition Ratin g Operating %Operating Bus2 Under Voltage 11kV 10.758 97.8 Bus 3 Under Voltage 11kV 10.655 96.9 7 CONCLUSION In this paper Load Flow study using ETAP software is carried out with an approach to overcome the problemof an under voltage. Load Flow Studies using ETAP Software is an excellent tool for system planning. A number of operating procedures can be analyzed such as the loss of generator, a transmission line, a transformer or a load. Load flow studies can be used to determine the optimum size and location of capacitors to surmount the problem of an under voltage.
- 4. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 04 Issue: 02 | Feb -2017 www.irjet.net p-ISSN: 2395-0072 © 2017, IRJET | Impact Factor value: 5.181 | ISO 9001:2008 Certified Journal | Page 773 Also, they are useful in determining the system voltages under conditions of suddenly applied or disconnectedloads. Load flow studies determine if system voltages remain within specifiedlimitsunder variouscontingencyconditions, and whether equipment such as transformers and conductors are overloaded. Load-flowstudiesareoftenused to identify the need for additional generation, capacitive, or inductive VAR support, or the placement of capacitors and/or reactors to maintain systemvoltageswithinspecified limits. References [1] Keith Brown, Herminio Abcede, Farookh Shokooh, Gary Donner “Interactive Simulation of Power Systems: ETAP applications and techniques”, Page(s): 1930-1941,IEEE ,1990. [2] J. Arrillaga, N.R. Watson “Computer Modelling of Electrical Power Systems”, second edition, ISBN : 978-0-471-87249-8 , John Wiley and Sons[2001]. [3] Rohit Kapahi “Load Flow Analysis of 132 kV substation using ETAP Software’ International Journal of Scientific &EngineeringResearchVolume 4, Issue 2, February-2013 ISSN 2229-5518 [4] Charles Mozina, “Undervoltage Load Shedding”, ISBN: 978-1-4244-0855-9, IEEE, Page(s): 39-54. [5] Glenn W. Stagg and Ahmed H. El-Abiad, “Computer Methods in Power System Analysis”, McGraw-Hill [1968]. [6] M.A.Pai, “Computer Techniques in Power System Analysis”, second edition, ISBN: 0-07-059363-9, Tata McGraw Hill [2005].