Optimal dg placement using multiobjective index and its effect on stability 2

409 views

Published on

Published in: Technology, Business
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
409
On SlideShare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
11
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Optimal dg placement using multiobjective index and its effect on stability 2

  1. 1. INTERNATIONAL JOURNAL OF ELECTRICAL ENGINEERING International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 – 6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME & TECHNOLOGY (IJEET)ISSN 0976 – 6545(Print)ISSN 0976 – 6553(Online)Volume 4, Issue 2, March – April (2013), pp. 202-218 IJEET© IAEME: www.iaeme.com/ijeet.aspJournal Impact Factor (2013): 5.5028 (Calculated by GISI) ©IAEMEwww.jifactor.com OPTIMAL DG PLACEMENT USING MULTIOBJECTIVE INDEX AND ITS EFFECT ON STABILITY AND FIELD RELAYS Dr.T.Ananthapadmanabha1, H Pradeepa2, Likith Kumar. M. V 3, Maruthi Prasanna.H.A.3, Veeresha.A.G.3, Pradeep N4 1 Professor, Dept of EEE, NIE, Mysore, Karnataka, India. 2 Asst. Professor, Dept of EEE, NIE, Mysore, Karnataka, India. 3 Research Scholar, Dept of EEE, NIE, Mysore, Karnataka, India. 4 Lecturer, Dept of EEE, Govt. Polytechnic, Karwar, Karnataka, India. ABSTRACT As the yearly electric energy demand grows, there is a significant increase in the penetration of distributed generation (DG) to fulfil this increase in demand. Increase in the number of DG is partly attributed to the new deregulated environment and the advent of new concepts as the smart grid. Penetration of a DG into an existing distribution system has many impacts on the system, with the power system protection being one of the major issues. DG causes the system to lose its radial power flow, besides the increased fault level of the system caused by the interconnection of the DG. Short circuit power of a distribution system changes when its state changes. This may result in elongation of fault clearing time and hence disconnection of equipments in the distribution system or unnecessary operation of protective devices. This paper presents a Multiobjective performance index (MOI) for distribution networks with distributed generation which considers a wide range of technical issues for optimal placement of DG. Distributed generation is extensively located on the IEEE-9Bus test feeder, IEEE-33Bus Radial Distribution Feeder and Practical 24Bus Distribution Feeder Located at Hassan. The Transient Stability studies are carried out by plotting terminal voltage, frequency and swing curve of DG with respect to main grid. From this we found critical clearing time and angle which is useful for relay co-ordination. The Directional and Non-Directional Over Current Relay Co-ordination (OCR) is carried out for radial 9-Bus radial system by considering without and with DG placement. Keywords: Distributed Generation (DG), Multi objective index (MOI), MiPower, Over Current Relay Co-ordination (ORC).Single line Diagram (SLD). 202
  2. 2. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEMEI. INTRODUCTION Traditional Concept of Power Systems Electricity generation is produced in largepower plants, usually located close to the primary energy source (for instance: coil mines)and far away from the consumer centres. Electricity is delivered to the customers using alarge passive transmission and distribution infrastructure, which involves high voltage (HV),medium voltage (MV) and low voltage (LV) networks. These distribution networks aredesigned to operate radially. The power flows only in one direction: from upper voltagelevels down-to customers situated along the radial feeders. New Concept of Power Systems technologies allow the electricity to be generated insmall sized plants. In this new conception, some of the energy-demand is supplied by thecentralized generation and another part is produced by distributed generation. The electricityis going to be produced closer to the customers [1], [2] Faults generally results in high current levels in electrical power systems. Thesecurrents are used to decide the occurrence of faults and require protection devices, which maydiffer in design depending on the complexity and accuracy necessary. The ordinary type ofprotection devices are thermo-magnetic switches, moulded-case circuit breakers (MCCBs),fuses, and over-current relays. Amongst these types, over-current relay is the most commonprotection device used to counteract excessive currents in power systems [3]. An over-current protection relay is a device able to sense any change in the signal,which it is receiving normally from a current and/or voltage transformer and carry out aspecific operation in case that the incoming signal is outside a predetermined range. Usuallythe relay operates closing or opening electrical contacts, as for example the tripping of acircuit breaker [4], [5]. In this paper case study and their results are presented. Cases gives a solution to theoptimal location of DG considering IMO for same rating of DG with Lag, Lead and Unitypower factor for standard radial test system and also for practical distribution system. Westudied the terminal voltage, frequency and swing curve of DG w.r.t. main grid by conduction3phase to ground fault at buses by using MiPower software [6]. Finally we discussed andproposed a solution of relay co-ordination to a 9bus radial system with and without DG,considering directional and non-directional relays using MiPower software.II. PROBLEM STATEMENT Nowadays, the use of renewable sources of energy has reached greater importance asit promotes sustainable living and with some exceptions (biomass combustion) does notcontaminant. Renewable sources can be used in either small-scale applications away from thelarge sized generation plants or in large-scale applications in locations where the resource isabundant and large conversion systems are used. Nevertheless, problems arise when the newgeneration is integrated with the power distribution network, as the traditional distributionsystems have been designed to operate radially, without considering the integration of thenew generation in the future. In radial systems, the power flows from upper terminal voltagelevels down to customers situated along the radial feeders .Therefore, over-current protectionin radial systems is quite straightforward as the fault current can only flow in one direction.With the increase of penetration of DG, distribution networks are becoming similar totransmission networks where generation and load nodes are mixed (“mesh” system) and morecomplex protection design is needed. In this new configuration, design considerations 203
  3. 3. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEMEregarding the number, size location and technology of the DG connected must be taken intoaccount as the short circuit levels are affected and miss coordination problems withprotection devices may arise. We carried out Relay co-ordination for radial 9 Bus system by placing directionalrelays and Non directional relays without DG connected and after addition of DG as affectsboth the coordination as well as the instantaneous high current setting of the primary andbackup relays. The Plug, Time and instantaneous settings were calculated and relay co-ordination was carried with addition of DG. We tried to investigate transient stability of the power system while the test systemwas subjected to a particular fault. In that case, the test system was investigated by applying afault to a specific distribution line and at the buses afterwards it was assumed that the faulthad been cleared by tripping the faulty line after certain fault duration. Then by plotting thebehavior of the DG rotor angle, voltage and frequency w.r.t main generator the criticalclearing time and angle will be noted down.III. PERFORMANCE INDICES A set of indices is proposed to quantify some of the technical benefits of DG. Theyare ILp, ILq, IVD, ISC1 and ISC3.[1]A. Real and Reactive Power Loss Index (ILp and ILq ) The major potential benefit offered by DG is the reduction in electrical line losses.The loss can be significant under heavy load conditions. With the inclusion of DG, line lossin the distribution system can be reduced. Obviously, line-loss reductions are due toreductions in power flows resulting from the introduction of DG. However, depending on theratings and locations of DG units, it is possible to have an increase in lo(and unrealistic)penetration levels. The first two indices (ILp & ILq) [1] express respectively as, Re{Losses k } ILp k = 1 − Re{Losses 0 } ....… (1) Im{Lossesk } ILqk = 1 − Im{Losses0 } …… (2)Where lossesk is the total complex power losses for the kth distribution networkconfiguration, and losseso is the total complex power losses for the distribution networkwithout DG.B. Voltage Drop Index (IVD) One advantage of careful location and sizing of DG is the enhancement of thevoltage profile. By introducing DG in the system, voltage profile can be improved becauseDG can provide a portion of the real and reactive power to the load, thus helping to decrease 204
  4. 4. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEMEcurrent along a section of the distribution line, which, in turn, will result in a boost in thevoltage magnitude at the customer site.  VΦ 0 − VΦ ki  NN −1 IVD k = 1 − max   VΦ 0  i=1   …… (3)Where Φ are the phases a, b, and c; VΦ 0 are the voltages at the root node (equal inmagnitude for the three phases); Φ ki are the voltages at node i for the kth distributionnetwork configuration; and NN is the number of nodes.C. Three-Phase and Single-Phase-to-Ground Short Circuit Short-Circuit currents introduce potentially destructive energy in the form of heat andmagnetic forces in a power system. Historically the distribution network has been designed toaccommodate power flow from the grid supply points downward through tiers of networksoperating at lower voltage to the electricity consumers. The ISC3 and ISC1 are related to theprotection and selectivity issues since they evaluate the maximum short-circuit currentvariation between the scenarios with and without DG. These indices give the power engineera notion of how the DG impacts on the protection devices that were planned for a networkwithout such generation units. Hence, a low impact on this concern means close-to-unityvalues for ISC3 and ISC1 indices[1] I   SCabc 0  ISC 1 k = 1 − max  i  I   SCabc k   i  …….. (4)  I   SCabc 0  ISC 3 k = 1 − max  i   I   SCabc k   i  ………. (5)Where I is the three-phase fault current value in node i for the kth distribution network SCabc kiconfiguration, I is the three-phase fault current value in node for the distribution SCabc 0 inetwork without DG.IV. PROBLEM FORMULATION A Multiobjective performance index for the performance calculation of distributionsystems for DG location is proposed in this work. It considers all previously mentionedindices by strategically giving a weight for each one. This could be performed, since allimpact indices are normalized (values between 0 and 1). The weighting factors are chosenbased on the importance and criticality of the different loads and according to the objectives 205
  5. 5. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEMEof the system operator that may be assigned from the power quality measures andcomponents capabilities of the power system.The Multiobjective performance index [1] is given by: w1ILp k + w2 ILq k + w3IVD k   k  IMO =   + w4 ISC1 + w5ISC 3  k k   5 ∑ wi = 1.0 Λ wi ∈ [0,1] i =1 ……….. (6) Multiobjective performance index for networks with DG takes into account all indicesby strategically giving a weighting factor to each one. This allows them to be related and aunique index to indicate the extent of DG impact, in a global manner, on a distributionnetwork. These relevance factors are intended to give the corresponding importance to eachtechnical issue (impact indices) due to the presence of DG and depend on the requiredanalysis (e.g., planning, regular operation, emergency operation). Furthermore, the relevancefactors should be flexible since electric utilities present different concerns about losses,voltages, protection schemes, etc. This flexibility makes the proposed methodology evenmore suitable as a tool for finding the most beneficial places where DGs may be inserted,regarding the electric utilities’ technical perspective and, consequently, regarding the DGowner’s economic perspective since utilities may incentivize (or even disincentives)connections points that are more beneficial based on the technical impacts.V. SIMULATION STUDY AND RESULTSA. TYPICAL RADIAL DISTRIBUTION SYSTEM The system under study is nine-bus radial distribution test system typical distributionsystem with a generator connected to a grid. Fig.5.1 Single-line diagram of radial system A total load of 0.8375 pu (on a 400 MVA base) is located unevenly at various buses andthere are 8 transmission lines. First load flow is conducted from this total real power, reactivepower losses and voltages at all the buses are noted down. Then by conducting short circuit 206
  6. 6. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEMEfaults at all the buses (SLG and 3PH-G) short circuit currents are noted down. Placing the DGat bus-2 again load flow analysis and short circuit analysis are conducted then by placing DGat each different bus at each location the above induces are calculated. After finding allindices valves by giving relevant weighing factors total MOI is calculated. Fig.5.2 Single line diagram of Radial 9bus system drawn in MiPower Software Fig.5.3 Graph of ILp& ILq Index Fig.5.4 Graph of Voltage Drop Index The optimal location of Distributed Generator by considering Multiobjective index(MOI) is Bus-8.The above DG considered is of 0.05 pu on 400 MVA base with 0.9 pf. i.e.18MW & 8.717Mvar. The optimal location of DG for lagging power factor will be at bus-6and for unity power factor will be at bus-8. 207
  7. 7. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME Fig.5.5 Graph of Single phase to ground fault & three phase to ground fault index Fig.5.6 Graph of Total Multi objective index valves at each busFig.5.7 Graph of Total Multi objective index valves by considering different power factor for rating of DGB. PRACTICAL DISTRIBUTION SYSTEM The Hassan distribution sub-station is located on the Banglore-Manglore road. It hasundergone many changes in the past few decades. In this system, the 220 kV bus is beingtapped which is running from Shimoga main receiving station to Mysore receiving station.Another line runs from Hassan to Nittur. The 220 kV is stepped down to 66 kV by using two100 MVA power transformers. Then it is again stepped down by using a 20 MVA and12.5MVA transformers in MUSS, Santhepet, Hassan. At present there are 11 feeders whichdistribute power to Hassan town and surrounding areas. Out of these 11 feeders a particularfeeder known as Water Works feeder is taken for analysis. 208
  8. 8. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME Fig.5.8: Simplified Water Works Feeder Network Fig.5.9 Graph of Total Multi objective index valves at each bus for 24-bus system The optimal location of Distributed Generator by considering Multiobjective index (IMO)is Bus-19.C. ANALYSIS OF TERMINAL VOLTAGE, FREQUENCY AND SWING CURVES OFDG For NINE bus system the optimal location of DG is at Bus-8 Case-1: Three Phase toground fault near Grid Starting at 1 sec and clearing at 2.33 sec system is stable (1.33 sec). Fig.5.10 Swing Curve of DG w.r.t. Grid (1-2.33sec) Fig.5.11 Generator terminal voltage of DG w.r.t. Grid (1-2.33sec) 209
  9. 9. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME Fig.5.12 Frequency of DG w.r.t. Grid (1-2.33sec) The three phase to ground fault is applied at bus-1 fault is initiated at 1 sec andcleared at 2.33 sec. The rotor angle of DG w.r.t Grid plot is as shown in fig.5.10. Theterminal voltage and frequency behaviour is shown in fig.5.11 and fig.5.12 respectively,system is stable. Fig.5.13 Swing Curve of DG w.r.t. Grid (1-2.34sec) Fig.5.14 Generator terminal voltage of DG w.r.t. Grid (1-2.34sec) Fig.5.15 Frequency of DG w.r.t. Grid (1-2.34sec) The three phase to ground fault is applied at bus-1 fault is initiated at 1 sec andcleared at 2.34 sec. The rotor angle w.r.t Grid plot is as shown in fig.5.13. The terminalvoltage and frequency behaviour is shown in fig.5.14 and fig.5.15 respectively, system isunstable. 210
  10. 10. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME From the above figures we can conclude that when fault near grid the critical clearingtime is more than the fault near DG. The rotor angle of DG will swings more when fault nearDG than near grid. By knowing Critical clearing time (cct) and critical clearing angle (cca) we cananalyse the generators behaviour, voltage stability range and frequency stability. If the swingrange of DG w.r.t grid crosses 1800 in positive or negative direction then system will lose itssynchronism and leads system to instability. The cct and cca will indicate the over current relay operating time near to grid and or DG,for case 1 when fault near grid the relay should operate with in by 1.33 sec if it fails tooperate then the system will be unstable and DG loses its synchronism.D. OVER CURRENT RELAY CO-ORDINATION FOR 9 BUS RADIAL DISTRIBUTIONSYSTEM Referring to Figure 1, the 9-bus radial system, we will do over current relay (OCR)co-ordination for last feeder for the bus 1, 4, 6, 8.The assumption is done because even iffault occurs near bus 3, 5, 7, 9 it will not effect for last feeder part i.e. for bus 4, 6, 8.Directional over current relay Co-ordination for Last feeder of 9bus without DG Fig.5.16 Directional OCR Co-ordination for last feeder without DG Fig.5.17 Curves for Directional OCR Co-ordination for last feeder without DG The last feeder of 9 bus is as shown in above Fig.5.16 SLD was developed inMiPower software. To do relay co-ordination we need fault current at the buses, byconducting 3phase to ground fault at all the buses the fault currents at each buses is as shownin figure 5.16. 211
  11. 11. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME Since one source is present the fault current will flow from source to load. Here RelayR2 acts back up for R3, R1 is back up for R2 when fault occurs near line3 i.e. between bus3and bus4 R3 will acts instantaneously and isolate the faulty section if this relay fails to senseand not trip then R2 will acts as a backup relay the time of operation for R3 is 0.1 sec if itfails to operate then after a certain delay R2 will sense and trip at 0.5215sec.If fault occurs atline2 R2 will acts instantaneously at 0.25sec. When it fails then R1 will trip at 0.9296 sec asbackup relay for R2.Similarly if fault at line1 R1 will trip at 0.4 sec instantaneously. Faultnear line2 R2 should operate if R3 trips it leads to mal operation.RESULT OP.TIME REMOTE CLOSE IN FAULT PLUG SETTING OP.TIME FOR RELAY TYPE CURRENT(A) PRIM RELAY FAULT(SEC) FAULT(SEC) CHOOSEN CLOSE IN SETTING CT PRIM PRIM(A) RELAY (Amps) NAME PLUG T.D.S (%) 3396.6 0.9296 7100. CDAG- 0.41 0.4 R1 R2 50 175 1 00 31P(NI) 2923.0 0.5215 5900. CDAG- 0.23 0.25 R2 R1 50 100 5 00 31P(NI) DOES NOT BACK- 2138. CDAG- 0.05 *** 0.1 R3 50 50 UP 00 31P(NI)Directional over Current Relay Co-ordination for Last feeder for 9bus with DG Fig.5.18 Directional OCR Co-ordination for last feeder with DG Fig.5.19 Curves for Directional OCR Co-ordination for last feeder with DG 212
  12. 12. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEMEResult: OP.TIME FOR RELAY TYPE PRIM RELAY CURRENT(A) FAULT(SEC) FAULT(SEC) CHOOSEN CLOSE IN CLOSE IN SETTING SETTING REMOTE CT PRIM OP.TIME PRIM(A) RELAY FAULT (Amps) NAME PLUG PLUG T.D.S (%) R1 100 100 0.45 0.35 3396.61 0.8624 3800.00 R2 CDAG- 31P(NI) R2 50 100 0.290 0.20 2923.05 0.4789 6500.00 R1 CDAG- 31P(NI) R3 50 50 0.050 0.05 DOES NOT 5500.00 **** CDAG- BACK-UP 31P(NI) R4 50 50.00 0.600 0.40 317.37 1.6104 636.00 R5 CDAG- 31P(NI) R5 50 50.00 0.450 0.25 313.28 1.2147 630.00 R6 CDAG- 31P(NI) R6 50 50.00 0.300 0.10 DOES NOT 620.00 **** CDAG- BACK-UP 31P(NI) The above results are of directional OCR co-ordination for last feeder of 9bus byconnecting DG As previously discussed in results for Fig5.18 and 5.19 the relays only senseone flow of direction of fault current. After connecting DG at last bus then the radial behaviourof system will change then flow of fault current will be in both direction magnitude will dependon the level of contribution of grid and generator. The Relay co-ordination setting should besuch that w.r.t DG relay R5 should be acts backup to R6 and R4 backup to R5 theserequirements is important because the fault contribution level of DG fault current will bedecreasing for far away fault from DG. R1, R2, andR3 acts as Directional relay for fault currentflowing from grid. R4, R5 and R6 acts as directional relay for fault current flowing from DG.Directional over current relay Co-ordination for Middle feeder for 9bus without DG Fig.5.20 Directional OCR Co-ordination for middle feeder without DG 213
  13. 13. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME Fig.5.21 Curves for Directional OCR Co-ordination for Middle feeder without DGResult: FAULT(SE FAULT(SE CHOOSEN CURRENT CLOSE IN CLOSE IN SETTING SETTING REMOTE OP.TIME OP.TIME CT PRIM PRIM(A)RELAY RELAY RELAY FAULT (Amps)NAME PLUG PLUG TYPE PRIM T.D.S FOR (%) (A) C) C) 31P(NI) 4560.00 380.36 1.1448 93.00 0.630 0.55 100 R1 R2 31P(NI) 3224.72 6800.00 120.00 0.7764 0.460 0.4 R2 R3 50 31P(NI) 2924.54 6000.00 0.3820 73.00 0.250 0.25 R3 R4 50 DOES NOT BACK-UP 31P(NI) 2000.00 50.00 0.050 **** 0.05 R4 50Directional over Current Relay Co-ordination for Middle feeder for 9bus withDistributed Generator Fig.5.22 Directional OCR Co-ordination for middle feeder with DG 214
  14. 14. RELAY R8 R7 R6 R5 R4 R3 R2 R1 NAME Result: CT PRIM 50 50 50 50 50 50 50 100 CHOOSE N (Amps) PLUG 73.00 73.00 120.00 160.00 50.00 73.00 120.00 93.00 SETTING (%) PLUG 0.470 0.340 0.160 0.050 0.050 0.250 0.460 0.630 SETTING PRIM(A) 0.55 0.45 0.35 0.25 0.05 0.20 0.30 0.40 S T. D. DOES DOES CLOSE 316.23 313.28 308.94 NOT NOT 2924.54 3224.72 3803.36 IN215 BACK- BACK- FAULT UP UP CURREN T(A) OP.TIME 1.4911 1.0835 0.6723 0.3820 0.7764 1.1448 FOR CLOSE IN FAULT(S and R8 acts as directional relay for fault current flowing from DG. EC) OP.TIME 635.00 628.00 620.00 610.00 2000.00 6000.00 6800.00 4560.00 REMOTE FAULT(S EC) PRIM R7 R6 R5 **** **** R4 R3 R2 RELAY Fig.5.23 Curves for Directional OCR Co-ordination for Middle feeder with DG RELAY 31P(NI) 31P(NI) 31P(NI) 31P(NI) 31P(NI) 31P(NI) 31P(NI) 31P(NI) TYPE 6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 – R1, R2, R3 and R4 acts as Directional relay for fault current flowing from grid. R5, R6, R7
  15. 15. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME For fault at line 4 R4 will acts instantaneously if fails to operate R3 will acts after acertain delay but R8 will act for contribution of fault current from DG. The relay settingshould be such that R1 acts back up to R2, R2 for R3 and R3 for R4 for fault contributionfrom main generator. R8 acts back up for R7, R7 backup for R6 and R6 backup for R5 forcontribution of fault current from DG.VI. CONCLUSION By introducing DG in the system, voltage profile can be improved because DG canprovide a portion of the real and reactive power to the load locally, thus helping to decreasecurrent along a section of the distribution line, which, in turn, will result in a boost in thevoltage magnitude at the customer site. The proposed Weighting factors are flexible since electric utilities have differentconcerns about losses, voltages, protection schemes, etc. By knowing Critical clearing time (cct) and critical clearing angle (cca) we cananalyse the generators rotor angle behaviour voltage stability range and frequency stability.Integration of the feeder with the DG adds another current source to the whole system. Thisaffects both the coordination as well as the instantaneous high current setting of the primaryand backup relays.VII. REFERENCES[1] Luis F. Ochoa, Student Member, IEEE, Antonio Padilha-Feltrin, Member, IEEE, and Gareth P. Harrison, Member, IEEE “Evaluating Distributed Generation Impacts with a Multiobjective Index” IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 21, NO. 3, JULY 2006[2] Pathomthat Chiradeja, Member, IEEE, and R. Ramakumar, Life Fellow, IEEE “An Approach to Quantify the Technical Benefits of Distributed Generation” IEEE TRANSACTIONS ON ENERGY CONVERSION, VOL. 19, NO. 4, DECEMBER 2004.[3] Hussein. A. Attia, M. El-Shibini, Z.H. Osman, and Ahmed A. Moftah “An Assessment of a Global Performance Index for Distributed Generation Impacts on Distribution Systems” Proceedings of the 14th International Middle East Power Systems Conference (MEPCON’10), Cairo University, Egypt, December 19-21, 2010, Paper ID 310.[4] T.MashauS.KibaaraS.ChowdhuryS.P.Chowdhury, “Impact of Distributed Generation on Protection Coordination in a Radial Distribution Feeder” UPEC 2011 · 46th International Universities Power Engineering Conference · 5-8th September 2011 · Soest · Germany.[5] Impact of distributed generation on distribution system by Angel FernándezSarabia June 2011 Aalborg, Denmark[6] PRDC Technical Document and MiPower Manual.[7] Dr.T.Ananthapadmanabha, MaruthiPrasanna.H.A, Veeresha.A.G and LikithKumar. M. V, “A New Simplified Approach for Optimum Allocation of a Distributed Generation Unit in the Distribution Network for Voltage Improvement and Loss Minimization”, International Journal of Electrical Engineering & Technology (IJEET), Volume 4, Issue 2, 2013, pp. 165 - 178, ISSN Print : 0976-6545, ISSN Online: 0976-6553. 216
  16. 16. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEMEAUTHORS’ DETAIL Dr. T. Ananthapadmanabha received the B.E. degree in Electrical Engineering in 1980, M.Tech degree in Power Systems (1st Rank) in 1984 and Ph.D. degree (Gold Medal) in 1997 from University of Mysore, Mysore. He is presently working as Professor in Department of Electrical and Electronics Engineering and Controller of Examinations at The National Institute of Engineering, Mysore, Karnataka, India. His research interest includes Reactive Power Optimization, Voltage Stability, Distribution Automation and AI applications to Power Systems. Mr. H. Pradeepa obtained his B.E (Electrical) degree from University Visvesvaraya College of Engineering (UVCE) in 2002, M.Tech degree in Power System from NITK, Suratkal . His research interest includes Reactive Power Optimization, Voltage Stability, Distribution Automation and AI applications to Power Systems. Likith Kumar. M. V. received the B.E. degree in Electrical & Electronics Engineering in 2011 from SKIT, Bangalore. He is presently pursuing research work at Department of Electrical and Electronics Engineering, The National Institute of Engineering, Mysore, Karnataka, India. His research interest includes Smart Grid, Communication System, Renewable Energy. Maruthi Prasanna. H. A. received the Diploma in Electrical & Electronics Engineering in 2004 from D.R.R.Government Polytechnic, Davanagere and B.E. degree in Electrical & Electronics Engineering in 2011 from B.M.S.Evening College of Engineering, Bangalore. He is presently pursuing research work at Department of Electrical and Electronics Engineering, The National Institute of Engineering, Mysore, Karnataka, India. His research interest includes Distribution System Optimisation, Power System Stability studies, A.I. applications to power system and Smart Grid. 217
  17. 17. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME Veeresha. A. G. received the B.E. degree in Electrical & Electronics Engineering in 2003 from SJMIT, Chitraduraga. He is presently pursuing research work at Department of Electrical and Electronics Engineering, The National Institute of Engineering, Mysore, Karnataka, India. His research interest includes Wind Energy, Distribution System Design, Distributed Generation. Pradeep. N obtained his B.E (Electrical & Electronics) degree from SIET, Tumkur, India in 2010 and M.Tech in Power System from NIE, Mysore. His research interest includes Wind Energy Systems, Distribution system Automation, Computer Applications to Power System, Distributed Generation, Renewable Energy Sources, Transformers, and Transmission and Distribution. 218

×