Power System Security Group

Department of Electrical and Computer Engineering

Iowa State University

• A. Ramapuram-Matavalam; V. Ajjarapu, "Sensitivity based Thevenin Index with Systematic Inclusion of Reactive Power Limits", IEEE Transactions on Power Systems, 2017, vol1, issue99, pp1-1 - link

• S. Li; V. Ajjarapu; M. Djukanovic, "Adaptive Online Monitoring of Voltage Stability Margin via Local Regression", IEEE Transactions on Power Systems, 2017, vol1, issue99, pp1-1 - link

• A. Ashok; M. Govindarasu; V. Ajjarapu, "Online Detection of Stealthy False Data Injection Attacks in Power System State Estimation", IEEE Transactions on Smart Grid, 2017, vol1, issue99, pp1-1 - link

• A. R. R. Matavalam; V. Ajjarapu, "Implementation of user defined models in a real-time cyber physical test-bed", 2016 National Power Systems Conference (NPSC), 2016, vol1, issue99, pp1-6 - link

• A. Radaideh; V. Ajjarapu, "Extracting expedient short term services from Homogeneous Group of Thermostatically Controlled Loads", 2016 IEEE Power & Energy Society Innovative Smart Grid Technologies Conference (ISGT), 2016, vol1, issue99, pp1-5 - link

• J. A. V. Vásquez; A. R. R. Matavalam; V. Ajjarapu, "Fast calculation of Thévenin equivalents for real-time steady state voltage stability estimation", 2016 North American Power Symposium (NAPS), 2016, vol1, issue99, pp1-7 - link

• A. Ashok; M. Govindarasu; V. Ajjarapu, "Attack-resilient measurement design methodology for State Estimation to increase robustness against cyber attacks", 2016 IEEE Power and Energy Society General Meeting (PESGM), 2016, vol1, issue99, pp1-5 - link

• A. Tiwari; V. Ajjarapu, "Addressing short term voltage stability problem - Part I: Challenges and plausible solution directions", 2016 IEEE/PES Transmission and Distribution Conference and Exposition (T&D), 2016, vol1, issue99, pp1-5 - link

• A. Tiwari; V. Ajjarapu, "Addressing short term voltage stability problem - Part II: A case study", 2016 IEEE/PES Transmission and Distribution Conference and Exposition (T&D), 2016, vol1, issue99, pp1-5 - link

• A. Radaideh; V. Ajjarapu, "Demand Response planning in day-ahead market for improving power system flexibility with high wind penetration levels", 2015 North American Power Symposium (NAPS), 2015, vol1, issue99, pp1-6 - link

• A. Reddy; V. Ajjarapu, "PMU based real-time monitoring for delayed voltage response", 2015 North American Power Symposium (NAPS), 2015, vol1, issue99, pp1-6 - link

• A. Singhal; V. Ajjarapu, "Impact assessment and sensitivity analysis of distribution systems with DG", 2015 North American Power Symposium (NAPS), 2015, vol1, issue99, pp1-6 - link

• A. R. R. Matavalam; V. Ajjarapu, "Calculating the long term voltage stability margin using a linear index", 2015 IEEE Power & Energy Society General Meeting, 2015, vol1, issue99, pp1-5 - link

• A. Tiwari; V. Ajjarapu, "A computer package for multi-contingency constrained reactive power planning", 2015 IEEE Power & Energy Society General Meeting, 2015, vol1, issue99, pp1-5 - link

• Shiyang Li; V. Ajjarapu, "Real-time monitoring of long-term voltage stability via local linear regression", 2015 IEEE Power & Energy Society General Meeting, 2015, vol1, issue99, pp1-5 - link

• Guangchao Geng; V. Ajjarapu; Quanyuan Jiang, "A hybrid dynamic optimization approach for stability constrained optimal power flow", 2015 IEEE Power & Energy Society General Meeting, 2015, vol1, issue99, pp1-1 - link

• M. Paramasivam; S. Dasgupta; U. Vaidya; V. Ajjarapu, "Entropy-based metric for characterization of delayed voltage recovery", 2015 IEEE Power & Energy Society General Meeting, 2015, vol1, issue99, pp1-1 - link

• M. Paramasivam; S. Dasgupta; V. Ajjarapu; U. Vaidya, "Contingency Analysis and Identification of Dynamic Voltage Control Areas", IEEE Transactions on Power Systems, 2015, vol30, issue6, pp2974-2983 - link

• S. Dasgupta; M. Paramasivam; U. Vaidya; V. Ajjarapu, "Entropy-Based Metric for Characterization of Delayed Voltage Recovery", IEEE Transactions on Power Systems, 2015, vol30, issue5, pp2460-2468 - link

• S. Dasgupta; M. Paramasivam; U. Vaidya; V. Ajjarapu, "PMU-Based Model-Free Approach for Real-Time Rotor Angle Monitoring", IEEE Transactions on Power Systems, 2015, vol30, issue5, pp2818-2819 - link

• A. Reddy; K. Ekmen; V. Ajjarapu; U. Vaidya, "PMU based real-time short term voltage stability monitoring — Analysis and implementation on a real-time test bed", 2014 North American Power Symposium (NAPS), 2014, vol1, issue99, pp1-6 - link

• M. Paramasivam; A. Salloum; V. Ajjarapu; V. Vittal; N. Bhatt; S. Liu, "Dynamic optimization based reactive power planning to mitigate slow voltage recovery and short term voltage instability", 2014 IEEE PES General Meeting | Conference & Exposition, 2014, vol1, issue99, pp1-1 - link

• A. R. R. Matavalam; V. Ajjarapu, "Long term voltage stability thevenin index using voltage locus method", 2014 IEEE PES General Meeting | Conference & Exposition, 2014, vol1, issue99, pp1-5 - link

• S. Dasgupta; M. Paramasivam; U. Vaidya; V. Ajjarapu, "Real-time monitoring of short-term voltage stability using PMU data", 2014 IEEE PES General Meeting | Conference & Exposition, 2014, vol1, issue99, pp1-1 - link

• N. A. Brown; V. Ajjarapu; N. Navid, "Economic dispatch with deliverable ramping capability constraint for high wind penetration", 2014 IEEE PES General Meeting | Conference & Exposition, 2014, vol1, issue99, pp1-5 - link

• G. Geng; V. Ajjarapu; Q. Jiang, "A Hybrid Dynamic Optimization Approach for Stability Constrained Optimal Power Flow", IEEE Transactions on Power Systems, 2014, vol29, issue5, pp2138-2149 - link

• G. Geng; V. Ajjarapu; Q. Jiang, "Application of automatic differentiation in power system trajectory sensitivity analysis", 2014 IEEE PES T&D Conference and Exposition, 2014, vol1, issue99, pp1-5 - link

• J. Yu; W. Li; V. Ajjarapu; W. Yan; X. Zhao, "Identification and location of long-term voltage instability based on branch equivalent", IET Generation, Transmission & Distribution, 2014, vol8, issue1, pp46-54 - link

• G. Geng; Q. Jiang; V. Ajjarapu, "Performance analysis for two-level parallel transient stability constrained optimal power flow", 2013 North American Power Symposium (NAPS), 2013, vol1, issue99, pp1-6 - link

• S. Dasgupta; M. Paramasivam; U. Vaidya; V. Ajjarapu, "Real-Time Monitoring of Short-Term Voltage Stability Using PMU Data", IEEE Transactions on Power Systems, 2013, vol28, issue4, pp3702-3711 - link

• M. Paramasivam; A. Salloum; V. Ajjarapu; V. Vittal; N. B. Bhatt; S. Liu, "Dynamic Optimization Based Reactive Power Planning to Mitigate Slow Voltage Recovery and Short Term Voltage Instability", IEEE Transactions on Power Systems, 2013, vol28, issue4, pp3865-3873 - link

• J. Yu; W. Li; V. Ajjarapu; W. Yan; X. Zhao, "Approach to trace and locate long-term voltage instability risk in power system planning", IET Generation, Transmission & Distribution, 2013, vol7, issue5, pp483-490 - link

• B. Fateh; M. Govindarasu; V. Ajjarapu, "Wireless Network Design for Transmission Line Monitoring in Smart Grid", IEEE Transactions on Smart Grid, 2013, vol4, issue2, pp1076-1086 - link

• B. Leonardi; V. Ajjarapu, "An approach for real time voltage stability margin control via reactive power reserve sensitivities", IEEE Transactions on Power Systems, 2013, vol28, issue2, pp615-625 - link

• K. K. Yagnik; V. Ajjarapu, "Consideration of the wind and solar generation reactive power capability on grid voltage performance", 2012 IEEE Power and Energy Society General Meeting, 2012, vol1, issue99, pp1-7 - link

• S. Dasgupta; M. Paramasivam; U. Vaidya; V. Ajjarapu, "PMU-based model-free approach for short term voltage stability monitoring", 2012 IEEE Power and Energy Society General Meeting, 2012, vol1, issue99, pp1-8 - link

• P. Xu; X. Wang; V. Ajjarapu, "Continuation power flow with adaptive stepsize control via convergence monitor", IET Generation, Transmission & Distribution, 2012, vol6, issue7, pp673-679 - link

• M. H. Fan; C. S. Wang; V. Ajjarapu, "Power system equilibrium tracing and bifurcation detection based on the continuation of the recursive projection method", IET Generation, Transmission & Distribution, 2012, vol6, issue3, pp199-206 - link

• B. Leonardi; V. Ajjarapu; M. Djukanovic; P. Zhang, "A practical two-stage online voltage stability margin estimation method for utility-scale systems", 2011 IEEE Power and Energy Society General Meeting, 2011, vol1, issue99, pp1-9 - link

• S. Sarkar; V. Ajjarapu, "MW Resource Assessment Model for a Hybrid Energy Conversion System With Wind and Solar Resources", IEEE Transactions on Sustainable Energy, 2011, vol2, issue4, pp383-391 - link

• C. Luo; V. Ajjarapu, "Sensitivity-Based Efficient Identification of Oscillatory Stability Margin and Damping Margin Using Continuation of Invariant Subspaces", IEEE Transactions on Power Systems, 2011, vol26, issue3, pp1484-1492 - link

• A. Tiwari; V. Ajjarapu, "Optimal Allocation of Dynamic VAR Support Using Mixed Integer Dynamic Optimization", IEEE Transactions on Power Systems, 2011, vol26, issue1, pp305-314 - link

• C. Luo; V. Ajjarapu, "A New Method of Eigenvalue Sensitivity Calculation Using Continuation of Invariant Subspaces", IEEE Transactions on Power Systems, 2011, vol26, issue1, pp479-480 - link

• B. Leonardi; V. Ajjarapu, "Development of Multilinear Regression Models for Online Voltage Stability Margin Estimation", IEEE Transactions on Power Systems, 2011, vol26, issue1, pp374-383 - link

• H. Bai; V. Ajjarapu, "A Novel Online Load Shedding Strategy for Mitigating Fault-Induced Delayed Voltage Recovery", IEEE Transactions on Power Systems, 2011, vol26, issue1, pp294-304 - link

• M. Fan; V. Ajjarapu; C. Wang; D. Wang; C. Luo, "RPM-Based Approach to Extract Power System Steady State and Small Signal Stability Information From the Time-Domain Simulation", IEEE Transactions on Power Systems, 2011, vol26, issue1, pp261-269 - link

• B. Leonardi; V. Ajjarapu; M. Djukanovic; P. Zhang, "Application of multi-linear regression models and machine learning techniques for online voltage stability margin estimation", 2010 IREP Symposium Bulk Power System Dynamics and Control - VIII (IREP), 2010, vol1, issue99, pp1-10 - link

• S. Yang; V. Ajjarapu, "A Speed-Adaptive Reduced-Order Observer for Sensorless Vector Control of Doubly Fed Induction Generator-Based Variable-Speed Wind Turbines", IEEE Transactions on Energy Conversion, 2010, vol25, issue3, pp891-900 - link

• B. Lee; S. G. Kang; S. Seo; V. Ajjarapu; H. Song, "Generation re-dispatch algorithm against voltage collapse in Jeju island system with a frequency control by high-voltage direct current", IET Generation, Transmission & Distribution, 2010, vol4, issue5, pp609-619 - link

• R. Dai; J. D. McCalley; D. C. Aliprantis; V. Ajjarapu; T. Das; D. Wu; M. A. Riaz; R. U. Imtiaz, "Hierarchical control for hybrid wind systems", 41st North American Power Symposium, 2009, vol1, issue99, pp1-6 - link

• C. Luo; V. Ajjarapu, "Invariant subspace based eigenvalue tracing for power system small-signal stability analysis", 2009 IEEE Power & Energy Society General Meeting, 2009, vol1, issue99, pp1-9 - link

• H. Liu; L. Jin; J. McCalley; R. Kumar; V. Ajjarapu; N. Elia, "Planning reconfigurable reactive control for voltage stability limited power systems", 2009 IEEE Power & Energy Society General Meeting, 2009, vol1, issue99, pp1-1 - link

• P. Vijayan; S. Sarkar; V. Ajjarapu, "A novel voltage stability assessment tool to incorporate wind variability", 2009 IEEE Power & Energy Society General Meeting, 2009, vol1, issue99, pp1-8 - link

• R. J. Konopinski; P. Vijayan; V. Ajjarapu, "Extended Reactive Capability of DFIG Wind Parks for Enhanced System Performance", IEEE Transactions on Power Systems, 2009, vol24, issue3, pp1346-1355 - link

• H. Bai; P. Zhang; V. Ajjarapu, "A Novel Parameter Identification Approach via Hybrid Learning for Aggregate Load Modeling", IEEE Transactions on Power Systems, 2009, vol24, issue3, pp1145-1154 - link

• H. Liu; L. Jin; J. D. McCalley; R. Kumar; V. Ajjarapu; N. Elia, "Planning Reconfigurable Reactive Control for Voltage Stability Limited Power Systems", IEEE Transactions on Power Systems, 2009, vol24, issue2, pp1029-1038 - link

• S. Yang; V. Ajjarapu, "Sensorless Control of the Doubly-Fed Induction Generator for Wind Energy Generations Using a Speed-Adaptive Full-Order Flux Observer", 2009 Twenty-Fourth Annual IEEE Applied Power Electronics Conference and Exposition, 2009, vol1, issue99, pp1951-1957 - link

• H. Song; B. Lee; V. Ajjarapu, "Control strategies against voltage collapse considering undesired relay operations", IET Generation, Transmission & Distribution, 2009, vol3, issue2, pp164-172 - link

• S. Sarkar; P. Vijayan; D. C. Aliprantis; V. Ajjarapu, "Effect of grid voltage unbalance on operation of a bi-directional converter", 2008 40th North American Power Symposium, 2008, vol1, issue99, pp1-7 - link

• C. Luo; V. Ajjarapu, "Fast identification of oscillatory stability margin and damping margin using continuation of invariant subspaces with sensitivity", 2008 40th North American Power Symposium, 2008, vol1, issue99, pp1-7 - link

• Gang Shen; V. Ajjarapu, "Trajectory optimization for voltage control via receding horizon control and mixed-integer programming", 2008 IEEE Power and Energy Society General Meeting - Conversion and Delivery of Electrical Energy in the 21st Century, 2008, vol1, issue99, pp1-7 - link

• A. Tiwari; V. Ajjarapu, "Optimal allocation of dynamic VAR for enhancing stability and power quality", 2008 IEEE Power and Energy Society General Meeting - Conversion and Delivery of Electrical Energy in the 21st Century, 2008, vol1, issue99, pp1-7 - link

• B. Leonardi; V. Ajjarapu, "Investigation of various generator reactive power reserve (GRPR) definitions for online voltage stability/security assessment", 2008 IEEE Power and Energy Society General Meeting - Conversion and Delivery of Electrical Energy in the 21st Century, 2008, vol1, issue99, pp1-7 - link

• Hua Bai; V. Ajjarapu, "Transmission system vulnerability assessment based on practical identification of critical relays and contingencies", 2008 IEEE Power and Energy Society General Meeting - Conversion and Delivery of Electrical Energy in the 21st Century, 2008, vol1, issue99, pp1-8 - link

• M. Anitha; S. Subramanian; R. Gnanadass; V. Ajjarapu, "Transient stability constrained optimal power dispatch with linear ramping model", 2008 IEEE Power and Energy Society General Meeting - Conversion and Delivery of Electrical Energy in the 21st Century, 2008, vol1, issue99, pp1-7 - link

• A. Tiwari; V. Ajjarapu, "Contingency assessment for voltage dip and short term voltage stability analysis", 2007 iREP Symposium - Bulk Power System Dynamics and Control - VII. Revitalizing Operational Reliability, 2007, vol1, issue99, pp1-8 - link

• Cheng Luo; V. Ajjarapu, "Modified algorithm to trace critical eigenvalues of power system with sensitivities via continuation of invariant subspaces", 2007 iREP Symposium - Bulk Power System Dynamics and Control - VII. Revitalizing Operational Reliability, 2007, vol1, issue99, pp1-9 - link

• Hua Bai; Venkataramana Ajjarapu, "Relay margin trajectory based identification of transmission vulnerability for power system security assessment", 2007 iREP Symposium - Bulk Power System Dynamics and Control - VII. Revitalizing Operational Reliability, 2007, vol1, issue99, pp1-9 - link

• A. Tiwari; V. Ajjarapu, "Event Identification and Contingency Assessment for Voltage Stability via PMU", 2007 39th North American Power Symposium, 2007, vol1, issue99, pp413-420 - link

• E. Vittal; J. D. McCalley; V. Ajjarapu; T. Harbour, "Wind Penetration Limited by Thermal Constraints and Frequency Stability", 2007 39th North American Power Symposium, 2007, vol1, issue99, pp353-359 - link

• G. Shen; V. Ajjarapu, "A Novel Algorithm Incorporating System Status to Prevent Undesirable Protection Operation during Voltage Instability", 2007 39th North American Power Symposium, 2007, vol1, issue99, pp373-378 - link

• A. Tiwari; V. Ajjarapu, "Reactive Power Cost Allocation Based On Modified Power Flow Tracing Methodology", 2007 IEEE Power Engineering Society General Meeting, 2007, vol1, issue99, pp1-7 - link

• D. Yang; V. Ajjarapu, "Critical Eigenvalues Tracing for Power System Analysis via Continuation of Invariant Subspaces and Projected Arnoldi Method", 2007 IEEE Power Engineering Society General Meeting, 2007, vol1, issue99, pp1-9 - link

• D. Yang; V. Ajjarapu, "Critical Eigenvalues Tracing for Power System Analysis via Continuation of Invariant Subspaces and Projected Arnoldi Method", IEEE Transactions on Power Systems, 2007, vol22, issue1, pp324-332 - link

• S. Yang; V. Ajjarapu; B. Zhang, "Test Loadability of Power Systems using A Networked Power Electronic Devices Control and Measurement System", 2006 CES/IEEE 5th International Power Electronics and Motion Control Conference, 2006, vol1, issue, pp1-5 - link

• A. Tiwari; V. Ajjarapu, "Modified Methodology for Tracing Power Flow", 2006 38th North American Power Symposium, 2006, vol1, issue99, pp317-322 - link

• Haifeng Liu; Licheng Jin; J. McCalley; R. Kumar; V. Ajjarapu, "Planning minimum reactive compensation to mitigate voltage instability", 2006 IEEE Power Engineering Society General Meeting, 2006, vol1, issue99, pp7 pp.- - link

• Xiaoyu Wen; V. Ajjarapu, "Application of a novel eigenvalue trajectory tracing method to identify both oscillatory stability margin and damping margin", IEEE Transactions on Power Systems, 2006, vol21, issue2, pp817-824 - link

• D. Yang; V. Ajjarapu, "A decoupled time-domain Simulation method via Invariant subspace partition for power system analysis", IEEE Transactions on Power Systems, 2006, vol21, issue1, pp11-18 - link

• Qin Wang; Hwachang Song; V. Ajjarapu, "Continuation-based quasi-steady-state analysis", IEEE Transactions on Power Systems, 2006, vol21, issue1, pp171-179 - link

• Licheng Jin; Haifeng Liu; R. Kumar; J. D. Mc Calley; N. Elia; V. Ajjarapu, "Power system transient stability design using reachability based stability-region computation", Proceedings of the 37th Annual North American Power Symposium, 2005., 2005, vol1, issue99, pp338-343 - link

• Haifeng Liu; Licheng Jin; J. D. McCalley; R. Kumar; V. Ajjarapu, "Linear complexity search algorithm to locate shunt and series compensation for enhancing voltage stability", Proceedings of the 37th Annual North American Power Symposium, 2005., 2005, vol1, issue99, pp344-350 - link

• K. Miu; V. Ajjarapu; K. Butler-Purry; D. Niebur; C. Nwankpa; N. Schulz; A. Stankovic, "Testing of shipboard power systems: a case for remote testing and measurement", IEEE Electric Ship Technologies Symposium, 2005., 2005, vol1, issue99, pp195-201 - link

• Dan Yang; V. Ajjarapu, "A decoupled method for power system time domain simulation via invariant subspace partition", IEEE Power Engineering Society General Meeting, 2005, 2005, pp1330-1335 Vol. 2 - link

• Haifeng Liu; Licheng Jin; V. Ajjarapu; R. Kumar; J. D. McCalley; N. Elia; V. Vittal, "Reachability analysis based minimal load shedding determination", IEEE Power Engineering Society General Meeting, 2005, 2005, pp1775-1781 Vol. 2 - link

• Dan Yang; V. Ajjarapu, "Tracing of critical eigenvalues for power system analysis via continuation of invariant subspaces and projected Arnoldi method", IEEE Power Engineering Society General Meeting, 2005, 2005, pp1630-1636 Vol. 2 - link

• Licheng Jin; Haifeng Liu; R. Kumar; V. Ajjarapu; J. D. McCalley; N. Elia; V. Vittal, "An application of reachable set analysis in power system transient stability assessment", IEEE Power Engineering Society General Meeting, 2005, 2005, pp1715-1719 Vol. 2 - link

• Yuan Zhou; V. Ajjarapu, "A Fast Algorithm for Identification and Tracing of Voltage and Oscillatory Stability Margin Boundaries", Proceedings of the IEEE, 2005, vol93, issue5, pp934-946 - link

• Qin Wang; V. Ajjarapu, "A novel approach to implement generic load restoration in continuation-based quasi-steady-state analysis", IEEE Transactions on Power Systems, 2005, vol20, issue1, pp516-518 - link

• Yuan Zhou; V. Ajjarapu, "A novel approach to trace time-domain trajectories of power systems in multiple time scales", IEEE Transactions on Power Systems, 2005, vol20, issue1, pp149-155 - link

• V. Ajjarapu, "Welcome to NAPS 2005", Proceedings of the 37th Annual North American Power Symposium, 2005., 2005, ppv-vi - link

• X. Wen; V. Ajjarapu, "Critical eigenvalue trajectory tracing for power system oscillatory stability assessment", IEEE Power Engineering Society General Meeting, 2004., 2004, pp1883-1889 Vol.2 - link

• P. Kundur; J. Paserba; V. Ajjarapu; G. Andersson; A. Bose; C. Canizares; N. Hatziargyriou; D. Hill; A. Stankovic; C. Taylor; T. Van Cutsem; V. Vittal, "Definition and classification of power system stability IEEE/CIGRE joint task force on stability terms and definitions", IEEE Transactions on Power Systems, 2004, vol19, issue3, pp1387-1401 - link

• Hwachang Song; Byongjun Lee; Sae-Hyuk Kwon; V. Ajjarapu, "Reactive reserve-based contingency constrained optimal power flow (RCCOPF) for enhancement of voltage stability margins", IEEE Transactions on Power Systems, 2003, vol18, issue4, pp1538-1546 - link

• Byongjun Lee; Hwachang Song; Sae-Hyuk Kwon; Gilsoo Jang; Jun-Hwan Kim; V. Ajjarapu, "A study on determination of interface flow limits in the KEPCO system using modified continuation power flow (MCPF)", IEEE Transactions on Power Systems, 2002, vol17, issue3, pp557-564 - link

• Yuan Zhou; V. Ajjarapu, "Identification and tracing of voltage and oscillatory stability margins", 2002 IEEE Power Engineering Society Winter Meeting. Conference Proceedings (Cat. No.02CH37309), 2002, pp250-255 vol.1 - link

• Yuan Zhou; V. Ajjarapu, "Local parameterization approach for unified time domain simulation of power system dynamics", 2002 IEEE Power Engineering Society Winter Meeting. Conference Proceedings (Cat. No.02CH37309), 2002, pp244-249 vol.1 - link

• H. Song; B. Lee; S. Kim; S. Kwon; J. Kim; V. Ajjarapu, "A Study on Determination of Interface Flow Limits in the KEPCO System Using Modified Continuation Power Flow (MCPF)", IEEE Power Engineering Review, 2002, vol22, issue8, pp67-67 - link

• Qin Wang; V. Ajjarapu, "Quasi-steady-state analysis by using continuation method [power system stability]", 2001 IEEE Power Engineering Society Winter Meeting. Conference Proceedings (Cat. No.01CH37194), 2001, pp1300-1304 vol.3 - link

• H. Song; S. Kim; B. Lee; S. H. Kwon; V. Ajjarapu, "Determination of interface flow margin using the modified continuation power flow in voltage stability analysis", IEE Proceedings - Generation, Transmission and Distribution, 2001, vol148, issue2, pp128-132 - link

• Zhihong Feng; V. Ajjarapu; D. J. Maratukulam, "A comprehensive approach for preventive and corrective control to mitigate voltage collapse", IEEE Transactions on Power Systems, 2000, vol15, issue2, pp791-797 - link

• Zhihong Feng; V. Ajjarapu; D. J. Maratukulam, "A comprehensive approach for preventive and corrective control to mitigate voltage collapse", 2000 IEEE Power Engineering Society Winter Meeting. Conference Proceedings (Cat. No.00CH37077), 2000, vol2, issue, pp1423 vol.2- - link

• Hwachang Song; Seulki Kim; Byongjun Lee; Sae-Hyuk Kwon; V. Ajjarapu, "Determination of interface flow margin for voltage stability analysis using the modified continuation power flow", 2000 Power Engineering Society Summer Meeting (Cat. No.00CH37134), 2000, pp32-37 vol. 1 - link

• Z. Feng; V. Ajjarapu; B. Long, "Identification of voltage collapse through direct equilibrium tracing", IEEE Transactions on Power Systems, 2000, vol15, issue1, pp342-349 - link

• S. Rajagopalan; V. V. Sastry; V. Ajjarapu; S. S. Venkata, "Object-oriented measurement templates for power electronics education and research using DYMOLA (Dynamic Modeling Laboratory)", COMPEL 2000. 7th Workshop on Computers in Power Electronics. Proceedings (Cat. No.00TH8535), 2000, vol1, issue99, pp166-171 - link

• B. Long; V. Ajjarapu, "The sparse formulation of ISPS and its application to voltage stability margin sensitivity and estimation", IEEE Transactions on Power Systems, 1999, vol14, issue3, pp944-951 - link

• Z. Feng; V. Ajjarapu; D. J. Maratukulam, "A practical minimum load shedding strategy to mitigate voltage collapse", IEEE Transactions on Power Systems, 1998, vol13, issue4, pp1285-1290 - link

• V. Ajjarapu; Zhihong Feng, "A novel approach for voltage collapse analysis and control", Power System Technology, 1998. Proceedings. POWERCON '98. 1998 International Conference on, 1998, pp1499-1503 vol.2 - link

• J. D. McCalley; V. Ajjarapu; J. De La Ree; A. G. Phadke; G. B. Sheble; S. S. Venkata; V. Vittal, "Multimedia courseware sparks interest in the industry", IEEE Computer Applications in Power, 1998, vol11, issue4, pp26-32 - link

• V. Ajjarapu; B. Lee, "Bibliography on voltage stability", IEEE Transactions on Power Systems, 1998, vol13, issue1, pp115-125 - link

• A. Ibsais; V. Ajjarapu, "The role of automatic differentiation in power system analysis", IEEE Transactions on Power Systems, 1997, vol12, issue2, pp592-597 - link

• B. Lee; V. Ajjarapu, "Invariant subspace parametric sensitivity (ISPS) of structure-preserving power system models", IEEE Transactions on Power Systems, 1996, vol11, issue2, pp845-850 - link

• J. D. McCalley; V. Ajjarapu; G. B. Sheble; V. Vittal, "Sophomore course development in power system analysis with interactive MATLAB modules", Proceedings of the 39th Midwest Symposium on Circuits and Systems, 1996, pp1101-1104 vol.3 - link

• Byongjun Lee; V. Ajjarapu, "A piecewise global small-disturbance voltage-stability analysis of structure-preserving power system models", IEEE Transactions on Power Systems, 1995, vol10, issue4, pp1963-1971 - link

• V. Ajjarapu, "Application of bifurcation and continuation methods for the analysis of power system dynamics", Proceedings of International Conference on Control Applications, 1995, vol1, issue99, pp52-56 - link

• V. Ajjarapu; Ping Lin Lau; S. Battula, "An optimal reactive power planning strategy against voltage collapse", IEEE Transactions on Power Systems, 1994, vol9, issue2, pp906-917 - link

• Byongjun Lee; V. Ajjarapu, "Factors to be considered in the study of voltage stability of structure preserving power system model", Proceedings of 36th Midwest Symposium on Circuits and Systems, 1993, pp700-703 vol.1 - link

• B. Lee; V. Ajjarapu, "Period-doubling route to chaos in an electrical power system", IEE Proceedings C - Generation, Transmission and Distribution, 1993, vol140, issue6, pp490-496 - link

• V. Ajjarapu, "Nonlinear static and dynamical aspects of power systems: a bifurcation approach", [Proceedings] 1992 IEEE International Symposium on Circuits and Systems, 1992, pp3013-3016 vol.6 - link

• V. Ajjarapu; B. Lee, "Bifurcation theory and its application to nonlinear dynamical phenomena in an electrical power system", IEEE Transactions on Power Systems, 1992, vol7, issue1, pp424-431 - link

• V. Ajjarapu; C. Christy, "The continuation power flow: a tool for steady state voltage stability analysis", IEEE Transactions on Power Systems, 1992, vol7, issue1, pp416-423 - link

• V. Ajjarapu; B. Lee, "A general approach to study static and dynamic aspects of voltage instability", [1992] Proceedings of the 31st IEEE Conference on Decision and Control, 1992, pp2916-2919 vol.3 - link

• V. Ajjarapu; Z. Albanna, "Application of genetic based algorithms to optimal capacitor placement", Proceedings of the First International Forum on Applications of Neural Networks to Power Systems, 1991, vol1, issue99, pp251-255 - link

• V. Ajjarapu; P. L. Lau, "An optimal strategy against voltage collapse", [1991] Proceedings of the 34th Midwest Symposium on Circuits and Systems, 1991, pp656-659 vol.2 - link

• V. Ajjarapu; C. Christy, "The continuation power flow: a tool for steady state voltage stability analysis", [Proceedings] Conference Papers 1991 Power Industry Computer Application Conference, 1991, vol1, issue99, pp304-311 - link

• V. Ajjarapu; B. Lee, "Bifurcation theory and its application to nonlinear dynamical phenomena in an electrical power system", [Proceedings] Conference Papers 1991 Power Industry Computer Application Conference, 1991, vol1, issue99, pp312-319 - link

• V. Ajjarapu; B. Lee, "Observation of bistable behavior in an electrical power system", [1991] Proceedings of the 34th Midwest Symposium on Circuits and Systems, 1991, pp660-661 vol.2 - link

• V. Ajjarapu; B. Lee, "Nonlinear oscillations and voltage collapse phenomenon in electrical power system", Proceedings of the Twenty-Second Annual North American Power Symposium, 1990, vol1, issue99, pp274-282 - link

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