Energy Saving Using D STATCOM Placement in Radial Distribution System under Reconfigured Network 1876 6102 © 2016 The Authors Published by Elsevier Ltd This is an open access article under the CC BY N[.]
Available online at www.sciencedirect.com ScienceDirect Energy Procedia 90 (2016) 124 – 136 5th International Conference on Advances in Energy Research, ICAER 2015, 15-17 December 2015, Mumbai, India Energy saving using D-STATCOM placement in radial distribution system under reconfigured network Atma Ram Guptaa*, Ashwani Kumarb a,b Department of Electrical Engineering, National Institute of Technology, Kurukshetra-136119, India Abstract High R/X ratio and significant voltage drop causes substantial power losses along the distribution network In this paper optimal location and size for D-STATCOM is determined for radial distribution networks under reconfigured network to reduce the power loss which in turns save the energy and environment The main contribution of the paper is: • D-STATCOM allocation using index vector method for radial distribution network with and without reconfiguration, • D-STATCOM size calculation using variational techniques for RDS with and without reconfiguration, • Impact of CP,CI,CZ, and realistic ZIP load model including load growth on D-STATCOM placement, • Energy Saving with improvement in voltage profile, reduction in power losses with D-STATCOM placement under reconfigured network, • Cost analysis with and without D-STATCOM Placement under reconfigured network, • Results are compared with existing technique proposed in literature The proposed method is tested for D-STATCOM allocation in IEEE 69-bus radial distribution systems Results show the considerable improvement in voltage profile, reduction in losses and, energy saving under reconfigured network © 2016 2016The TheAuthors Authors Published by Elsevier Ltd is an open access article under the CC BY-NC-ND license © Published by Elsevier Ltd This Peer-review under responsibility of the organizing committee of ICAER 2015 (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the organizing committee of ICAER 2015 Keywords: D-STATCOM; Radial distribution system; Optimum location; Optimum size; Reconfigured network Main text Around 13% of the total power generation is wasted as line losses in distribution system due to high R/X ratio and significant voltage drop along the distribution network Reduction of power loss is needed for economic operation of * Corresponding author Tel.: +91-9896279046 E-mail address: argupta@nitkkr.ac.in 1876-6102 © 2016 The Authors Published by Elsevier Ltd This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the organizing committee of ICAER 2015 doi:10.1016/j.egypro.2016.11.177 Atma Ram Gupta and Ashwani Kumar / Energy Procedia 90 (2016) 124 – 136 power system and it is main challenge of various researchers Many authors have proposed the network reconfiguration technique for reducing losses, load balancing, improving voltage profile as well as increasing the system loadability of RDS The network reconfiguration of RDS is a technique to find best configuration, which provides reduced power loss with maintaining all operating constraints, like voltage profile of all nodes, current capacity of the feeder, and radial structure of the network [1] Network reconfiguration technique was proposed for distribution network to reduce TPL and TQL as well as for load balancing in [2] Voltage stability of distribution system can also be improved by network reconfiguration as discussed in [3] Nomenclature RDS DG D-FACTS D-STATCOM Index[n] V[n] Iq[k] Ip[k] Qeff[n] total Q TPL TQL Vmin IV Radial distribution system Distributed generation Distribution Flexible AC Transmission System Distribution Static Compensator "Index” for nth bus Voltage at nth bus Imaginary component of current in branch Real component of current in branch Effective load at nth bus Total reactive load of the given distribution system Total Active Power loss Total Reactive Power loss Minimum bus voltage Index vector A two-stage algorithm for reconfiguration of balanced and unbalanced systems has been developed for reduction of losses in [4] Current flow is used instead of power flow for deciding the opening of switches in first stage and exchange of branch is proposed for loss reduction in next stage Hourly switching operation for improvement of voltage stability index considering different load at every bus is proposed in [5] Discrete Artificial Bee Colony is used for reconfiguring of network in [6] for improving the loadability of distribution network A new hybrid evolutionary algorithm based on combination of a New Fuzzy Adaptive Particle Swarm Optimization and Nelder– Mead simplex search method is used for reconfiguration in [7] Various researchers implemented series voltage regulator, shunt capacitors, distributed generation (DG) for maintaining voltages at an acceptable range and reducing losses of the distribution system But, series voltage regulator and shunt capacitors have some disadvantages, like conventional series voltage regulators cannot generate reactive power and have quite slow response because of their step by step operations The disadvantage with the shunt capacitors is that they cannot generate continuously variable reactive power Now-a-days, D-FACTS devices are used in the distribution systems at strategic locations to improve the system performance and overcome on the problems of series voltage regulator and shunt capacitors Immune algorithm is used to find optimal location and size of D-STATCOM in [8] Capacitors are placed in unbalanced distribution network to reduce losses as well as improvement in voltage profile [9, 10] D-STATCOM is placed in RDS for voltage profile improvement using voltage stability indicator in [11] An effective ways of D-STATCOM placement for various loading conditions are proposed in [12] Few, Authors have implemented simultaneous placement of DG and D-STATCOM [13], reconfiguration and DG [14], reconfiguration and capacitor [15], D-STATCOM and reconfiguration [16] to reduce power loss and improving the voltage profile The combination of distribution system reconfiguration and optimal placement of D-STATCOM is the effective way to reduce the losses in distribution network Reconfiguration also allows integrating more renewable energy sources in system [17] Simultaneous placement of both DG and DSTATCOM in reconfigured network is proposed for reduction of losses, improvement in voltage profile as well as for load balancing in [18] 125 126 Atma Ram Gupta and Ashwani Kumar / Energy Procedia 90 (2016) 124 – 136 It is found from literature survey that researchers have worked for D-STATCOM placement in reconfigured network by taking CP load But, in real power system loads are not constant This paper presents placement of DSTATCOM under reconfigured network for CP, CI, CZ and realistic ZIP load model including load growth Reconfiguration with D-STATCOM placement is a very effective technique for voltage profile improvement which in turns reduces the line losses and saves the energy In this study, load growth of % is considered for planning of distribution system for years First the load flow analysis is conducted on RDS for calculating line losses and voltage profile After this, index vector method [23] is used for finding optimal location of D-STATCOM for radial distribution network with and without reconfiguration The bus having the highest index vector as well as its normalized voltage is less than 1.01 is selected as candidate bus for D-STATCOM placement After identifying the optimal location, place the D-STATCOM at its optimal location and vary its size in steps from minimum value to a value equal to feeder loading capacity and run the load flow in each step in order to compute the losses The DSTATCOM size at which minimum real power loss occurs is selected as the optimal size Finally the load flow is carried out by compensating the obtained optimal size of D-STATCOM at the candidate bus for IEEE 69-bus test system for finding the improvement in voltage profile, reduction in losses and, energy saving under reconfigured network using MATLAB software version 7.8, 2009 [19] The organization of the paper is as follows Section explains the load flow analysis of RDS, modelling of load and index vector method for determination of optimal location of D-STATCOM and section describes the variational technique for finding optimum size of DSTATCOM for radial distribution network with and without reconfiguration Section explains the reconfiguration technique and section shows the results and comparison tables for the IEEE 69 bus RDS Load Flow Analysis of RDS Load flow analysis of distribution system differs from the transmission system The conventional Gauss Seidel and Newton Raphson method is used for transmission systems and their use in distribution system usually does not provide good results and very often solution diverges Load flow analysis used in this paper for RDS is based on forward and backward sweep algorithm on power basis [24] The complete flow chart for load flow analysis for RDS is shown in Fig Start Read the load data and line data of RDS Assume initial voltage, V=1pu at all bus Calculate net real and reactive power flows of all branches using backward propagation Update bus voltages and phase angles using forward propagation Is Load Flow Converged ? YES Find TPL, TQL and Voltage profile of all bus Stop Fig.1 Flow Chart for backward forward sweep method NO 127 Atma Ram Gupta and Ashwani Kumar / Energy Procedia 90 (2016) 124 – 136 In power basis load flow, the backward sweep is used to determine effective power at each node from far end of the feeder to sending end and the forward sweep is mainly bus voltage and power loss calculation from sending end to receiving end of a feeder or a lateral 2.1 Load Modeling The active and reactive powers for the static load models can be expressed in an exponential form as: ⎛V ⎞ P = P0 ⎜ ⎟ ⎝ V0 ⎠ np ⎛V ⎞ Q = Q0 ⎜ ⎟ ⎝ V0 ⎠ nq (1) (2) Where, and are the active and reactive powers at bus nominal voltage stands for bus load voltage and and are the load exponents [20] Here the value of both and is equal to zero for constant power (CP) load model Both and is equal to one, for constant current (CI) load model The value of and is equal to two for constant impedance (CZ) load model • ZIP load model ⎡ ⎤ ⎛V ⎞ ⎛V ⎞ P = Po ⎢ a p ⎜ ⎟ + bp ⎜ ⎟ + cp ⎥ V V ⎢ ⎥ ⎝ o ⎠ ⎝ o ⎠ ⎣ ⎦ ⎡ ⎤ ⎛V ⎞ ⎛V ⎞ Q = Qo ⎢ aq ⎜ ⎟ + bq ⎜ ⎟ + cq ⎥ V V ⎢ ⎥ ⎝ o ⎠ ⎝ o ⎠ ⎣ ⎦ (3) (4) where, the sum of the ZIP load coefficients for both P, and Q loads is equal to a p + bp + c p = , aq + bq + cq = , In this paper work 69 bus systems = =0.1, =0.1, =0.8, Po and Qo are the real and reactive power consumed at a reference voltage Vo 2.2 Load growth model Load i =Load × (1 + r) m (5) Where, r =annual growth rate, m=plan period up to which feeder can take the load and r=0.07 and m=5 for 69 bus test system 2.3 Index Vector Method Index Vector is calculated using the base case load flow of RDS, and calculating reactive component of current in the branches and reactive power load absorption at each bus [23] The line and load data of IEEE 69 bus RDS is taken from [20] The total active and reactive power loads of the system are 3802.19 kW and 2694.60 KVAr respectively First the base MVA and base kV used in this paper is 100 and 11 respectively, and then the results are also obtained with base value of 100 MVA and 12.66 kV respectively The Index-Vector for bus n is given by Index[n] = Iq[k] Qeff [n] + + Vn Ip[k ] total Q (6) After calculating index vectors at all buses, the magnitudes of normalized voltage are determined for all the buses by the following formula 128 Atma Ram Gupta and Ashwani Kumar / Energy Procedia 90 (2016) 124 – 136 Norm [i ] = V [i ] 0.95 (7) The node which has highest Index Vector as well as its normalized voltage is less than 1.01 will be considered as the optimal node for the placement of D-STATCOM The index vector profile for ZIP load model without load growth is shown in Fig It shows that index vector is maximum for 61st bus and hence selected for optimum DSTATCOM placement Index Vector profile shows 61st bus is the optimum bus for D-STATCOM placement for all CP, CI, CZ load model including realistic ZIP load model with load growth INDEX VECTOR 2.5 2.25 INDEX VECTOR 1.75 1.5 1.25 0.75 0.5 0.25 0 10 15 20 25 30 35 40 BUS NUMBER 45 50 55 60 65 70 Fig 2.The index vector profile without reconfiguration Variational technique 350 160 300 140 Active Power Loss in KW Active Power Loss in KW The size of D-STATCOM is calculated using the variational technique [10] D-STATCOM is placed at its optimal location and the variation of real power loss with D-STATCOM size for RDS with and without reconfiguration is determined and shown in Fig 3(a) and 3(b) respectively for 100 MVA and 11 kV base values Fig 4(a) and 4(b) shows the results of variational technique for 100 MVA and 12.66 kV base values The size gives the minimum loss is taken as optimum size of D-STATCOM Without reconfiguration optimum size is 1350 KVAr and with reconfiguration it reduces to 1075 KVAr for CP load model at both base values For ZIP load model the optimal size of D-STATCOM without and with reconfiguration are found 1200 and 1000 KVAr respectively Load growth of is also considered for planning of distribution system In this study, load growth of % is considered for years The optimal size of D-STATCOM for ZIP load model with load growth are found 1150 KVAr without reconfiguration and 1000 KVAr with reconfiguration 250 200 150 100 50 120 100 80 60 40 20 0 500 1000 1500 2000 2500 3000 Size of D-STATCOM in KVAR Fig 3(a) Variational Technique without reconfiguration 500 1000 1500 2000 2500 Size of D-STATCOM in KVAr Fig 3(b) Variational Technique with reconfigured network 129 250 120 200 100 TPL in KW TPL in KW Atma Ram Gupta and Ashwani Kumar / Energy Procedia 90 (2016) 124 – 136 150 100 50 80 60 40 20 0 500 1000 1500 2000 2500 Size of D-STATCOM in KVAr Fig 4(a) Variational Technique without reconfiguration 0 500 1000 1500 2000 2500 Size of D-STATCOM in KVAr Fig 4(b) Variational Technique with reconfigured network Reconfiguration procedure Distribution systems consist of two types of switches sectionalizing-switches (normally closed) and tie-switches (normally open) The design of RDS can be changed by opening sectionalizing switches and closing tie switches so that the radial arrangement of the network is maintained and all of the loads are supported at reduced power losses, improved voltage profile, improved power quality and increased system security The reconfiguration used in this paper for IEEE-69 bus RDS and the complete flow chart for reconfiguration procedure is explained in [20] Results The results are obtained for IEEE 69 bus RDS with various load model without and with D-STATCOM placement in reconfigured network The analysis has been carried out by developing codes in MATLAB version 7.8 on Windows Intel® Core™ i7 Processor ,1.8 GHz, RAM GB Impact of various load models along with load growth on system performance is evaluated in terms of voltage profile, power losses, cost of energy losses and annual energy savings enhancement Cost function of energy loss and D-STATCOM is taken from [21] and [22] respectively The complete steps of finding results without and with reconfiguration are shown in the flow chart of Fig 5(a) and 5(b) respectively Following four cases have been considered for analysis of results • Case-1: Without reconfiguration and without D-STATCOM placement • Case-2: Without reconfiguration and with D-STATCOM placement • Case-3: With reconfiguration and without D-STATCOM placement • Case-4: With reconfiguration and with D-STATCOM placement Table compares the results for CP load model at 100 MVA and 11 kV base values for all four cases It is found that line loss are reduced from 317.906 KW to 210.71 KW after D-STATCOM placement, further it is reduced to 134.616 KW after reconfiguring the network, then D-STATCOM is placed in reconfigured network and with implementation losses reduced to 98.993 KW Again, it has been found that line losses of the system reduce if the base kV values are increased by keeping base MVA constant Here, the base case losses are reduced from 317.906 KW to 225.13 KW by increasing the base kV from 11 to 12.66 kV Table compares the results of all four cases for CP load model at 100 MVA and 12.66 kV base values Table and Table compare the results for CI and CZ load model at 100 MVA and 11 kV base values for all four cases 130 Atma Ram Gupta and Ashwani Kumar / Energy Procedia 90 (2016) 124 – 136 Start Read the input Network Data ( load data and line data) Run Load Flow and find TPL and TQL Calculate Index Vector for each bus Find the bus offers maximum value of Index Vector (suppose jth bus ) Set optimum Location of D-STATCOM = jth bus Set QDSTATCOM = at bus jth Run Load Flow and Find TPLDSTATCOM TPLDSTATCOM New < TPLDSTATCOM QDSTATCOM = QDSTATCOM +SZ (SZ= Step Size) Yes No Set QDSTATCOM as optimum Size of DSTATCOM Set QDSTATCOM as optimum Size at optimal location jth bus Run Load Flow after DSTATCOM placement find Total Power Losses Stop Fig 5(a) Flow chart without reconfiguration Table Results obtained for D-STATCOM placement for CP load @ base MVA=100 and base kV=11 Parameters Case-1 Case-2 Case-3 Case-4 Total Active Power loss (KW) 317.906 210.71 134.616 98.993 Total Reactive Power loss (KVAr) 143.834 97.3747 125.451 91.001 Optimum Location for D-STATCOM Placement - @61st bus - @61st bus Optimum Size of D-STATCOM (KVAr) - 1350 - 1075 Minimum Bus Voltage (p.u) 0.8754 0.9062 0.93191 0.9547 Total Power loss reduction (KW) - 107.196 183.29 218.913 Annual Energy Loss (KWh) 2784856.60 1845819.60 1179236.20 867178.68 Annual Energy Saving (KWh) - 939036.96 1605620.40 1917677.90 Cost of Energy Loss in US $ ( 80.5 US $/ KWh) 224180953 148588478 94928514 69807884 Cost of D-STATCOM in US $ (70 US $/ KVAr) - 94500 - 75250 Annual Cost saving in US $ - 75497975 129252439 154297819 131 Atma Ram Gupta and Ashwani Kumar / Energy Procedia 90 (2016) 124 – 136 Start Read the input Network Data ( load data and line data) Reconfigure the network Run Load Flow and find TPL and TQL Calculate Index Vector for each bus Find the bus offers maximum value of Index Vector (suppose jth bus ) Set optimum Location of D-STATCOM = jth bus Set QDSTATCOM = at bus jth Run Load Flow and Find TPLDSTATCOM TPLDSTATCOM New < TPLDSTATCOM QDSTATCOM = QDSTATCOM +SZ (SZ= Step Size) Yes No Set QDSTATCOM as optimum Size of DSTATCOM Set QDSTATCOM as optimum Size at optimal location jth bus Run Load Flow after DSTATCOM placement find Total Power Losses Stop Fig 5(b) Flow chart with reconfigured network Table Results obtained for D-STATCOM placement for CP load @ base MVA=100 and base kV=12.66 Parameters Case-1 Case-2 Case-3 Case-4 Total Active Power loss (KW) 225.13 152.15 98.64 73.23 Total Reactive Power loss (KVAr) 102.22 70.53 92.06 67.38 Optimum Location for D-STATCOM Placement - @61st bus - @61st bus Optimum Size of D-STATCOM (KVAr) - 1350 - 1075 Minimum Bus Voltage (p.u) 0.90917 0.93101 0.94947 0.9663 Total Power loss reduction (KW) - 72.98 126.49 151.90 Annual Energy Loss (KWh) 1972138.80 1332834 864086.40 641494.80 Annual Energy Saving (KWh) - 639304.80 1108052.40 1330644 Cost of Energy Loss in US $ ( 80.5 US $/ KWh) 158757173.40 107293137 69558955.20 51640331.40 Cost of D-STATCOM in US $ (70 US $/ KVAr) - 94500 - 75250 Annual Cost saving in US $ - 51369536.40 89198218.2 107041592 132 Atma Ram Gupta and Ashwani Kumar / Energy Procedia 90 (2016) 124 – 136 Table Results obtained for D-STATCOM placement for CI load @ base MVA=100 and base kV=11 Parameters Case-1 Case-2 Case-3 Total Active Power loss (KW) Case-4 253.776 178.198 141.17 109.97 Total Reactive Power loss (KVAr) 116.34 83.37 115.70 95.18 Optimum Location for D-STATCOM Placement - @61st bus - @61st bus Optimum Size of D-STATCOM (KVAr) - 1300 - 1050 Minimum Bus Voltage (p.u) 0.9166 0.9374 0.9581 0.97168 Total Power loss reduction (KW) - 75.578 112.60 143.80 Annual Energy Loss (KWh) 2223077.760 1561014.4 1236649.20 963337.20 Annual Energy Saving (KWh) - 662063.36 986428.56 1259740.56 Cost of Energy Loss in US $ ( 80.5 US $/ KWh) 178957759.68 125661659.20 99550260.60 77548644.60 Cost of D-STATCOM in US $ (70 US $/ KVAr) - 91000 - 73500 Annual Cost saving in US $ - 53205100.48 79407499.08 101335615.08 The size of D-STATCOM reduces from 1300 to 1050 KVAr after reconfiguration of network with CI load model and line loss are reduced from 253.776 KW to 178.198 KW after D-STATCOM placement, further it is reduced to 141.17 KW after reconfiguring the network, then D-STATCOM is placed in reconfigured network and with implementation losses reduced to 109.17 KW.Table compares the results for realistic ZIP load model at 100 MVA and 11 kV base values for all four cases The size of D-STATCOM reduces from 1200 to 1000 KVAr after reconfiguration of network It is observed that line loss are reduced from 285.39 KW to 207.89 KW after DSTATCOM placement, further it is reduced to 144.672 KW after reconfiguring the network, then D-STATCOM is placed in reconfigured network and with implementation losses reduced to 115.525 KW Fig 6, Fig and Fig compares the voltage profile of all four cases for CP, CI and CZ load respectively at base MVA of 100 and base kV of 11 Table compares the results of above four cases for CP load at both base values with the existing results available in literature Table Results obtained for D-STATCOM placement for CZ load @ base MVA=100 and base kV=11 Parameters Case-1 Case-2 Case-3 Case-4 Total Active Power loss (KW) 229.03 156.35 136.52 103.53 Total Reactive Power loss (KVAr) 105.78 74.02 112.69 89.90 Optimum Location for D-STATCOM Placement - @61st bus - @61st bus Optimum Size of D-STATCOM (KVAr) - 1350 - 1050 Minimum Bus Voltage (p.u) 0.9219 0.94107 0.9598 0.9723 Total Power loss reduction (KW) - 72.68 92.51 125.50 Annual Energy Loss (KWh) 2006302.80 1369626.00 1195915.20 906922.80 Annual Energy Saving (KWh) - 636676.80 810387.60 1099380 Cost of Energy Loss in US $ ( 80.5 US $/ KWh) 161507375.40 110254893 96271173.60 73007285.40 Cost of D-STATCOM in US $ (70 US $/ KVAr) - 94500 - 73500 Annual Cost saving in US $ - 51157982.40 65236201.80 88426590 Load growth of is also considered for planning of distribution system In this study, load growth of % is considered for years and the results are given in Table Finally, the comparison of annual energy loss reduction and comparison of cost reduction by proposed technique in all four cases for CP load model, realistic ZIP load model and ZIP load model with load growth are shown in Fig and Fig 10 respectively Results show the considerable improvement in voltage profile, reduction in losses and, energy saving with D-STATCOM placement under reconfigured network 133 Atma Ram Gupta and Ashwani Kumar / Energy Procedia 90 (2016) 124 – 136 Table Results obtained for D-STATCOM placement for ZIP load @ base MVA=100 and base kV=11 Parameters Case-1 Case-2 Case-3 Case-4 Total Active Power loss (KW) 285.39 207.89 144.672 Total Reactive Power loss (KVAr) 129.82 96.13 117.95 115.525 100.00 Optimum Location for D-STATCOM Placement - @61st bus - @61st bus Optimum Size of D-STATCOM (KVAr) - 1200 - 1000 Minimum Bus Voltage (p.u) 0.91311 0.93087 0.9572 0.9707 Total Power loss reduction (KW) - 77.5 140.72 169.865 Annual Energy Loss (KWh) 2500016.40 1821116.40 1267326.72 1011999 Annual Energy Saving (KWh) - 678900 1232707.20 1488017.40 Cost of Energy Loss in US $ ( 80.5 US $/ KWh) 201251320.20 146599870.20 102019800.96 81465919.50 Cost of D-STATCOM in US $ (70 US $/ KVAr) - 84000 - 70000 Annual Cost saving in US $ - 54567450.00 99231519.24 119715400.70 Table Comparison of results obtained for D-STATCOM placement for CP load in reconfigured network Parameters [16], [18], Proposed Technique Proposed Technique 69 bus 33bus @12.66 kV base, 69 bus @ 11 kV base, 69 bus TPL in KW for Case-1 225 202.50 225.13 317.906 TPL in KW Case-4 78.59 110.22 73.23 98.993 TPL reduction (%) 65.07 45.57 67.47 68.86 Case-1 1.02 Case-2 Case-3 Case-4 Voltage in P.U 0.98 0.96 0.94 0.92 0.9 0.88 1.01 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67 Bus Number Fig Comparison of voltage profile for CP load @ base MVA=100 and base kV=11 Case-1 Case-2 Case-3 Case-4 Voltage in P.U 0.99 0.98 0.97 0.96 0.95 0.94 0.93 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 Bus Number Fig Comparison of voltage profile for CI load @ base MVA=100 and base kV=11 134 Atma Ram Gupta and Ashwani Kumar / Energy Procedia 90 (2016) 124 – 136 Case-1 Voltage in P.U 1.02 Case-2 Case-3 Case-4 0.98 0.96 0.94 0.92 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 Bus Number Annual Energy Loss in (KWh) Fig Comparison of voltage profile for CZ load @ base MVA=100 and base kV=11 6000000 5000000 Annual Energy Loss (KWh) for ZIP load model with load growth 4000000 3000000 Annual Energy Loss (KWh) for CP load model 2000000 1000000 Case-1 Case-2 Case-3 Case-4 Cost of Energy Loss in US Million $ Fig Comparison of Annual Energy loss reduction 450 400 Cost of Energy Loss in US million $ for ZIP load with load growth Cost of Energy Loss in US million $ for CP load 350 300 250 200 Cost of Energy Loss in US million $ for ZIP load 150 100 50 Case-1 Case-2 Case-3 Case-4 Fig 10 Comparison of Cost reduction Table Results obtained for D-STATCOM placement for ZIP load with load growth @ base MVA=100 and base kV=11 Parameters Case-1 Case-2 Case-3 Case-4 Total Active Power loss (KW) 596.56 441.55 287.79 231.85 Total Reactive Power loss (KVAr) 270.35 203.08 234.11 200.27 Optimum Location for D-STATCOM Placement - @61st bus - @61st bus Optimum Size of D-STATCOM (KVAr) - 1150 - 1000 135 Atma Ram Gupta and Ashwani Kumar / Energy Procedia 90 (2016) 124 – 136 Minimum Bus Voltage (p.u) 0.8703 0.9002 0.93844 0.9579 Total Power loss reduction (KW) - 155.01 308.77 364.71 Annual Energy Loss (KWh) 5225865.60 3867978 2521040.40 2031006 Annual Energy Saving (KWh) - 1357887.60 2704825.19 3194859.60 Cost of Energy Loss in US $ ( 80.5 US $/ KWh) 420682180.80 311372229 202943752.20 163495983 Cost of D-STATCOM in US $ (70 US $/ KVAr) - 80500 - 70000 Annual Cost saving in US $ - 109229451.80 217738428.60 257116197.80 Conclusions In this paper optimal D-STATCOM placement and size is obtained based on index vector method The analysis has been carried out on IEEE 69 bus distribution network with CP, CI, CZ, realistic ZIP and ZIP load model including load growth Based on the analysis carried out, the following conclusions are made: • Average CP load is slightly higher than ZIP load model, thereby D-STACOM rating is also slightly higher in CP than ZIP load model • With the D-STATCOM, there is significant improvement in voltage profile, reduction in power losses and cost of energy losses and there by annual energy savings are higher • Power losses increases with load growth accordingly, the required D-STATCOM KVAR support also increases to meet the load growth Annual energy savings obtained due to energy loss reduction is higher with load growth after installation of D-STATCOM For the optimal D-STATCOM size it is essential to determine the optimal location of the device due to its cost involved The selection of the location must result into optimal D-STATCOM ratings for better voltage profile, reduced losses, and lower cost of reactive support/KVAR The annual savings obtained with D-STATCOM without and with load growth are observed higher when the device is placed at 61st bus Hence, this study can help the system operator to plan the better distribution system with optimal reactive power planning Further, this work can also be extended with residential, commercial and industrial load model Acknowledgements The authors gratefully acknowledge the contribution of the MHRD, Govt of India for providing research facilities to the work reported in this paper References [1] Baran, M.E.and Wu, F.F., Network reconfiguration in distribution systems for loss reduction and load balancing, IEEE Transactions on Power Delivery, 1989; 4(2), 1401-1407 [2] Rao R S., Narasimham S.V.L., Raju M.R., and Rao A S., Optimal Network Reconfiguration of large-scale distribution system using harmony search algorithm, IEEE Trans on Power Syst., 2011; 26: 1080-1088 [3] # " )& !)& "))& ! ! ! " ! "! % ! 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Read the input Network Data ( load data and line data) Reconfigure the network Run Load Flow and find TPL and TQL Calculate Index Vector for each bus Find the bus offers maximum value of Index... Ashwani Kumar / Energy Procedia 90 (2016) 124 – 136 Start Read the input Network Data ( load data and line data) Run Load Flow and find TPL and TQL Calculate Index Vector for each bus Find the bus... value of Index Vector (suppose jth bus ) Set optimum Location of D- STATCOM = jth bus Set QDSTATCOM = at bus jth Run Load Flow and Find TPLDSTATCOM TPLDSTATCOM New < TPLDSTATCOM QDSTATCOM = QDSTATCOM