1. SEMINORON DG(distributiongeneration)
PLACEMENTIN DISTRIBUTIONNETWORK
PRESENTED BY
AJAY PRAKASH SINGH
PSE 152603
EEE NIT WARANGAL
Under the guidance of
SREE B. Nagu
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2. REFRENCE
IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 28, NO. 1
Voltage Stability Based DG Placement in Distribution Networks
BY
H. Ghasemi , S. Vaez Zadeh (senior member ,IEEE)
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3. content
1. What is DG?
2. Why DG?
3. Earlier used techniques
4. Techniques used in this paper
5. Case study
6. Application
7. Conclusion
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4. WhatisDistributedGeneration?
 The small energy-generation units which are connected to
distribution system are referred to as "Distributed Generation”.
 The best definition for DG is, "the source of electrical energy is
connected to distribution networks or directly to the consumer
side".
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5. POWERSYSTEMWITHOUTDG
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6. DistributedGenerationDiagram
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7. POWERSYSTEMWITHDG
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8. WHYDG?
 System Security
 Reliability
 Efficiency
 Quality
 Active Management of distribution network
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9. earlierusetechnique’s,How tooselectbestlocationfordg
 voltage stability index – most sensitive bus too voltage
collapse in radial distribution system
Problem – an equivalent two bus system is used for the
analysis of voltage stability
 bus indices – for considering the effect of aggregated dg in
voltage security of transmission grid are developed
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10. Newtechniquesfordgplacement
 Voltage stability technique –
• Modal analysis
• Continuous power flow
 Ranking method – priority list for dg location for compensating
reactive power
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11. ModalAnalysisforVoltageStabilityEvaluation
 A system is voltage unstable if for at least one bus in the system
bus voltage magnitude decreases as the reactive power injection at
the same bus is increased.
 other words, a system is voltage stable if V-Q sensitivity is
positive or every bus and unstable if V-Q sensitivity is negative
for at least one bus.
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12. ReducedJacobianMatrix
 The linearized steady state system power voltage equations are
given by-
∆P = incremental change in bus real power.
∆Q=incremental change in bus reactive power injection.
∆θ = incremental change in bus voltage angle.
∆V= incremental change in bus voltage magnitude.
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13. at each operating point we keep P constant and evaluate
voltage stability by considering the incremental relationship
between Q and V. To reduce the above equations we assume
∆P= ∆P=0.
 JR is called the reduced Jacobian matrix of the system. JR is
the matrix which directly relates the bus voltage magnitude and
bus reactive power injection.
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14. The ith mode of the Q-V response is defined by the ith eigenvalue ,
and the corresponding right and left eigenvectors.
Since
Using this in ∆V, we get
By defining v=η∆V vector of modal voltage variation
q= η∆Q vector of modal reactive power variation
We can write uncoupled first order equation as-
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15. Thus for ith mode voltage variation is -
Vi=1/ λi * qi
 If λi >0 , the ith modal voltage and the ith modal reactive power
variations move in the same direction, indicating voltage stability of
the system.
 whereas λi <0 refers to instability of the system.
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16. The relative contribution of the power at bus k in mode
i is
given by the bus participation factor
Pki= ℰ ki* η ki
Participation factors determine the most critical areas
which
 lead the system to instability.
 Higher the magnitude bus participation factor
better be the remedial action taken too stabilize the
mode.
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17. Continuouspowerflowmethodology
 Determination of max loading is one of the most important problem
in voltage stability analysis that can’t be calculated by model analysis.
This uses successive solution, to compute the voltage profile up too
the collapse point
 there jacobian become singular to determine voltage security margin
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18. DgplacementALGORITHM
DG Placement Process
The DG placement problem is solved here by using
modal analysis and the CPF method by an objective
of voltage security margin enhancement and loss
reduction.
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20. Dgplacementevaluationindices
 ALR – active loss reduction
 RLR – reactive loss reduction
higher values indicate better performance
VI index – lower value
better the performance of dg units
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21. SHORTTERMREACTIVEPOWERRANKING
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22. CASE STUDY
Application of DG placement Algorithm
Application of the placement method and the corresponding indices are
examined on the well-known 33-bus radial distribution network.
The system total apparent load is 4.3694 MVA and DG penetration in all
cases is considered to be 40% (i.e., 1.7477 MVA).
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23. MODIFIEDEQUIVALENTREACTIVEPOWERCOMPENSATION
METHOD(MERC)
 Uses (QLI) – to determine priority list of dg to compensate reactive
power shortages
It will not seek VSM
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24. APPLICATIONOFPLACEMENTALGORITHM
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25. System active and reactive losses for different placement scenarios
when DGs active power is limited to 0.4 total load and no voltage
regulation is performed by DGs.
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26. VOLTAGEPROFILEFORDIFFERENTPLACEMENTSCENARIOS
. osk
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27. The proposed placement algorithm is implementable in different DG
penetration scenarios
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28. Due to the radial nature of distribution networks, the buses of each
network branch, from the tail to the main feeder, usually have
participation factors in a descending order for a specific mode.
the 33-bus radial networks participation factors for mode 1 in descending
order when DG at bus 18
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29. APPLICATIONOFRANKINGMETHOD
.
Application of the ranking method is examined on all candidate buses
obtained from the placement algorithm, bus 28 is the best site for reactive
power compensation in the case of shortage.
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30. The places are ranked using an MERC method, which
determines a priority list of DG locations for reactive
power compensation during occasions of reactive power
shortage.
 The placement algorithm is executed and remedial
effect of DGs, both in loss reduction and voltage profile
improvement in normal operation, and enhancement of
the loading parameter in the case of voltage instability
The ranking method is executed over the obtained
candidates to provide a priority list from the view point of
reactive power compensation in the case of shortage.
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31. CONCLUSION
DG placement is different from the best location for reactive
power compensation and VSM in the presence of a voltage-
stability problem.
Long-term DG placement problem can be solved by CPF and
modal analysis while the short-term reactive power issues can be
addressed by the ranking method
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32. REFRENCES
R. Cossent, T. Gomez, and P. Fras, “Towards a future with large penetration of
distributed generation: Is the current regulation of electricity
distribution ready? Regulatory recommendations under a European perspective,” Int. J.
Energy Policy, vol. 37, pp. 1145–1155, 2009.
. Chakravorty and D. Das, “Voltage stability analysis of radial
distribution networks,
M. E. Baran and F. F. Wu, “Network recon figuration in distribution
systems for loss reduction and load balancing,” IEEE Trans. Power
H. A. Gil, M. E. Chehaly, G. Joos, and C. A. Caizares, “Bus-based
indices for assessing the contribution of DG to the voltage security
margin of the transmission grid,” presented at the IEEE Power Energy
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