Download
1 / 9
90 likes | 219 Views
This report details the advanced modeling and assessment of control devices, loads, and transactions essential for evaluating voltage stability in power systems. Tasks include modeling FACTS devices, tap-changing transformers, exciters, and loads, achieving various completion levels. Key findings reveal the optimism in static analysis margins, the significant role of dynamic reserves, and limitations of PV curve indicators. Additionally, a transaction-based stability margin and utilization factors calculation have been developed, showcasing the effectiveness of the new indices in predicting voltage stability issues.
E N D
Voltage Security Margin Assessment By Drs. G. Huang and A. AburStudents: N. Nair, L. Zhao H. Zhang( not paid through pserc)
Task 1: Modeling of control devices, loads and transactions for stability evaluations. • Modeling FACTS devices 70% Finished • Modeling Tap-changing transformers for its reactive power drawing capability 70% Finished • Modeling exciters 70% Finished • Modeling loads 70% Finished • Modeling transactions 40% Finished
Highlights: • Insight on Dynamic Reserve vs Static Reserve ( dynamic reserve paper) • Margin based on Static Analysis is 10% too optimistic for most cases • TCUL has major impacts on dynamic margin 30% or more • Voltage regulating exciters cannot be replaced by static var reserve.
Task 2 :Use of Stability Margin and Stability Index Calculations • Develop a program according to the new models to simulate the dynamic responses 70% Finished • Analysis of Modeling Impacts 40% Finished • Use of stability indices as a transaction scheduler • Use of utilization indices as basis for auxiliary service charges • Develop equipment investment indicators • Tests and documentation
Highlights • Weakness of PV curves are found. For some loads, the lower part of the PV curve do not indicate instability. • Indicator L gives an information as regards to the stability margin from the steady state voltage collapse point. • It has been observed that L calculated on the simulated dynamic data at the instance of the largest dip in the voltage at the load bus following a disturbance can give information as regards to the voltage stability margin. • An OPF based algorithm to evaluate load curtailment incorporating voltage stability margin has been formulated based on the proposed index L.
Task 3: Transaction based stability margin and utilization factors calculation • Formulate the transaction based power flow analysis problem 70% finished • Develop software for transaction based power flow analysis for decompositions 50% finished • Develop software to calculate utilization factor for control equipments • Develop software for finding decomposed utiliziation factors and stability margins for individual transactions. • Test case and documentation
Highlights • A transaction based power flow (TBPF) analysis and prototype program has been developed. • The utilization of MW flows, Mvar flows, MVA flows, transmission losses and reactive power losses of bilateral transactions is part of the TBPF solution. • Potentials for the deregulated power market, such as loss allocation, parallel flow evaluation, congestion management and settlement, reactive power pricing, Flowgate and ATC assessment etc • High computation efficiency • With appropriate logic modification, common power flow programs embedded in EMS function can be readily extended for TBPF purpose.
Desired Input from Industry: • Real measurement data that records voltage stability scenarios for us to check if our L index will correctly predict the problem. • Real measurement data that indicate PV curve monitoring do not work for lighting or resistance loads. But we will demonstrate that our L indicator will work.
