Long Vu

picture of campanile reflected in window
I am a Research Scientist and Lecturer at MIT MechE. Currently, I am interested in understanding the impact of increasing complexity on the dynamics of the electric power grid - a typical networked CPS. Though this giant system has worked properly for more than 100 years, it may abruptly behave unexpectedly under the large-scale integration of new components it was not designed to work with, e.g., distributed renewable sources and moving electric vehicles. At the same time, the increase of attacks/disasters and the reliance on control and communication are leading to new sources and paths of cascading failures. These shifts pose new challenges in keeping the grid working reliably and seamlessly. In my research, I ask questions such as: How would the power grid behave under extreme and new conditions? What conditions trigger instabilities and blackouts? What is the best action to prevent blackouts? How can the power grid be protected against cyberphysical attacks and disasters? What would a resilient network architecture that can reduce the risk of blackout look like?
Answering these questions can lead to a more secure and resilient power grid. To address them, I focus on creating analytic foundations by exploiting the grid's physical structure, harnessing the available data, and examining analogies with other fields, e.g., the brain and materials science. Also, I draw on tools from, and find ways to push the existing boundaries of, dynamics, control, and optimization. Having received funding from NSF and DOE, my research has resulted in some findings that can lead to changes in the existing paradigms.

Representative Publication:
1. "Reconfigurable microgrid architecture for blackout prevention", 2017 [pdf]
This paper introduces a plug-and-play architecture and a network reconfiguration scheme for resilient multi-microgrid networks. Unexpectedly, this architecture suggests that removing connections from a dense network may favor stability, a phenomenon that is counter-intuitive to the conventional wisdom.
2. "Inverse Stability of Power Systems", IEEE Control Systems Letters (L-CSS), accepted 2017 [pdf] [link]
This paper changes the way we think about the stability assessment problem. Instead of estimating the set of initial states leading to a given operating condition, we characterize the set of operating conditions that a power grid converges to from a given initial state under changes in power injections and lines.
3. "Structural Emergency Control Paradigm", IEEE Journal on Emerging and Selected Topics in Circuits and Systems, accepted 2017 [pdf][link]
This paper gives a non-traditional way to look at the control design problem. Instead of updating the control input to force the power system state to a fixed operating condition, we relocate the operating condition (by adjusting the impedance of some critical lines) to attract the emergency state.
4. "Toward Simulation-free Estimation of Critical Clearing Time", IEEE Trans. Power Systems, accepted 2016 [pdf][link]
This is among the first certificates for power systems transient stability without using any time-domain simulations...
5. "A Framework for Robust Assessment of Power Grid Stability and Resiliency", IEEE Trans. Automatic Control, accepted as a Full Paper, 2016 [pdf][link]
This paper presents robust certificates for the grids' stability w.r.t the fluctuation of power injections, and for the grids' ability to withstand a bunch sources of faults...
6. "Lyapunov Functions Family Approach to Transient Stability Assessment", IEEE Trans. Power Systems, vol. 31, no. 2, pp. 1269-1277, March 2016 [pdf] [link]
This work exploits advanced optimization techniques to significantly reduce conservativeness and computational complexity in the transient stability assessment...

Recent News:
  • Our paper, "Contraction and Robustness of Continuous Time Primal-Dual Dynamics" [pdf], was accepted to publish on the IEEE Control Systems Letters
  • Our paper, "A Robustness Measure of Transient Stability under Operational Constraints in Power Systems" [pdf], was accepted to publish on the IEEE Control Systems Letters
  • Our paper, "Robustness against Disturbances in Power Systemsunder Frequency Constraints" [pdf], was submitted to the IEEE Transactions on Control of Network Systems
  • I will present our group's research (together with Jean-Jacques Slotine) on the plug-and-play architecture of multi-microgrid networks at the 2nd SCONES, October 16-17, 2017. The poster is here: [pdf]
  • Our paper, "Inverse stability of power systems" [pdf], was accepted to publish in the IEEE Control Systems Letters
  • Our paper, "Structural Emergency Control Paradigm" [pdf], was published in the IEEE Journal on Emerging & Selected Topics in Circuits & Systems
  • Our paper, "Structural Emergency Control for Power Grids", was accepted to ACC2017 as an Invited Paper
  • We won the Best Paper Award at the IEEE ICSET2016 for our paper "Robust stability assessment of renewable power grids". Congratulations, Kostya!
  • Our paper, "Contraction Analysis for Nonlinear DAE Systems", was submitted to IEEE Trans. Automatic Control
  • Our proposal, "Structual remedial actions: Enabling high-penetration renewable power grids through intelligent network control", has concept paper accepted by DOE IDEAS program
  • I will serve as the Technical Programme Chair for the 4th IEEE International Conference on Sustainable Energy Technologies 2016
  • Jan 2016: The DOE proposal that I involved in writing with a big PANL-PNNL-MIT-Caltech team was funded. Congratulations!
  • Jan 2016: Our paper, "Towards Electronics-based Emergency Control in Power Grids with High Renewable Penetration" [pdf], was accepted as an invited paper to ACC2016
  • Jan 2016: Our paper, "A Framework for Robust Assessment of Power Grid Stability and Resiliency" [pdf], was accepted to publish in the IEEE Transactions on Automatic Control
  • Jan 2016: Our paper, "Toward Simulation-free Estimation of Critical Clearing Time" [pdf], was accepted to publish in the IEEE Transactions on Power Systems
  • Jul 2015: Our NSF proposal, "EAGER: Renewables: Collaborative Research: Market Designs for Distribution Systems with High Renewable Penetration", was recommended for funding. Congratulations Vijay, Kostya and Takashi!
  • Jun 2015: Our NSF proposal, "Collaborative Research: Computational Methods for Stability Assessment of Renewable Integrated Power Systems", was recommended for funding. Congratulations Kostya, Aranya and Dhagash!
  • Jun 2015: I will be serving as the IEEE Boston Section Control Systems Chapter Chair
  • Apr 2015: Our paper, "Lyapunov Functions Family Approach to Transient Stability Assessment", was accepted to publish on the IEEE Transactions on Power Systems
  • Mar 2015: Three papers were submitted to IEEE CDC 2015
  • Feb 2015: Our paper, "Geometry-based Estimation of Stability Region for A Class of Structure Preserving Power Grids", was accepted to IEEE PES General Meeting 2015
  • Jan 2015: Our invited paper, "Synchronization Stability of Lossy and Uncertain Power Grids", was accepted to ACC 2015
  • Jan 2015: Our paper, "Power Management for Electric Tugboats Through Operating Load Estimation", was accepted to publish on the IEEE Transactions on Control Systems Technology
Last updated 01/30/16