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 led to some findings that can change the existing paradigms.
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...