Voltage Security Margin Assessment

1
Voltage Security Margin Assessment

• Professor Dr. Garng Huang

PSERC
2

• Task 1
• Modeling of control devices, loads and
  transactions for stability evaluations.
• Subtasks
• 1.1 Modeling FACTS devices3
• 1.2 Modeling Tap-changing transformers for
  its reactive power drawing capability8
• 1.3 Modeling exciters for its reactive power
  supporting and voltage regulatingcapability6,8
• 1.4 Modeling loads8
• 1.4 Modeling transactions5,9,10
• Task 2
• Use of Stability Margin and Stability Index
  Calculations
• Subtasks
• 2.1. Develop a program according to the new
  models to simulate the dynamic responses4,8
• 2.2. Analysis of Modeling Impacts6,7
• 2.3. Use of stability indices as a transaction
  scheduler1,2
• 2.4 Use of utilization indices developed in 2.2
  as basis for auxiliary service charges.
  5,6,7,11
• 2.5 Use of 2.4 results as equipment investment
  indicators based on 2.4 results5,6,7

3

• Task 3
• Transaction based stability margin and
  utilization factors calculation
• Subtasks
• 3.1 Formulate the transaction based power
  flow analysis problem9,10,11
• 3.2 Develop software for transaction based power
  flow analysis for
• decompositions9,10
• 3.3 Develop software to calculate utilization
  factor for control equipments6
• 3.4 Develop software for finding decomposed
  utiliziation factors and stability
• margins for individual transactions. 5
• 3.5 Combining results from 3.2 and 3.3 to
  decompose the margins and utilization
• factors to individual transactions. 5,6

4
Publications

• 1. G M Huang, N C Nair, An OPF based Algorithm
  to Evaluate Load Curtailment Incorporating
  Voltage Stability Margin Criterion, Conference
  proceeding of NAPS 2001, TX.
• 2. G M Huang, N C Nair, Voltage Stability
  Constrained Load Curtailment Procedure to
  Evaluate Power System Reliability Measures,
  IEEE/PES WM 2002, NY
• 3. G M Huang, N C Nair, Incorporating TCSC into
  the Voltage Stability Constrained OPF
  Formulation, IEEE/PES Summer meeting 2002,
  Chicago.
• 4. G M Huang, N C Nair, Detection of Dynamic
  Voltage Collapse, IEEE/PES Summer meeting 2002,
  Chicago.
• 5. G M Huang, N C Nair, Allocating Usages of
  Voltage Security Margin in Deregulated Electric
  Markets, Submitted to ISCAS 2003, Thailand.
• 6. G M Huang, K Men, Contribution Allocation
  for Voltage Stability In Deregulated Power
  Systems , IEEE 2002 PES, Summer meeting,
  Chicago.
• 7. G M Huang, L Zhao, X Song, A new bifurcation
  analysis for power system dynamic voltage
  stability studies, IEEE 2002 PES, Summer
  Meeting, Chicago
• 8. G M Huang, H Zhang, Dynamic voltage stability
  reserve studies for deregulated environment
  IEEE 2001 PES, Summer Meeting, Canada
• 9. G M Huang, H Zhang, Transaction-Based Power
  Flow Analysis for Congestion Management and
  Responsibility Evaluation presented at 2001
  IEEE/PES Winter Meeting, Panel Session
  Transmission Congestion Management and
  Reliability, Columbus, Ohio, Jan. 2001.
• 10 . G M Huang, H Zhang, Transaction Based Power
  Flow analysis For Transmission Utilization
  Allocation 2001 IEEE/PES Summer Meeting.
• 11 . G M Huang, H Zhang, Transmission Loss
  Allocations and Pricing Via Bilateral Energy
  Transactions 1999 IEEE/PES Summer Meeting.

5
Voltage Stability Indicator
6
Voltage Stability Constrained OPF Formulation
7
Transaction Based Voltage Margin Allocation
8
TB-VMA Algorithm Step 1
Decompose nodal currents based on transactions
PX Pool type transaction TX NT Bilateral
transactions
Suffix Q represents the system wide reactive
market
9
TB-VMA Algorithm Step 2
Decompose nodal voltage components from
decomposed current components
Suffix , PX Pool type transaction TX NT
Bilateral transactions
Suffix Q represents the system wide reactive
market
10
TB-VMA Algorithm Step 3
Complex Power Delivered at Load buses, based on
scheduled transactions
Suffix, PX Pool type transaction TX NT
Bilateral transactions
11
Step 3 Continued
Index L formulation based on transaction based
voltage decomposition
Suffix, PX Pool type transaction TX NT
Bilateral transactions
12
TRANSACTION PATTERN
13
Line parameters
14
Result of TB-VMA with and without line
contingency of Line 4-9 outage
Index Evaluated at Buses Before Contingency
Index Evaluated at Buses After Contingency

• Transaction 2 of bus 7 increases the load bus 9
  index.
• Because generator at bus 2 is involved in both
  PX1 and TX 2.

• The above effect is magnified in case of a
  contingency.
• Bus 9 is driven closer towards voltage
  collapse. This is because of loss of
• support for bus 9 from generator 1 because of
  loss of line

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TB-VMA Application Scope

• Responsibility Settlement of Voltage Security
• Node-wise Voltage Stability Margin Utilization
  Evaluation
• Evolve Transaction Based Pricing Mechanism for
  Voltage Security
• A Tool to confirm whether a Transaction could be
  committed from voltage security margin viewpoint
• A Tool to decide which transaction if curtailed
  gives maximum effect in case of potential voltage
  collapse situation