285 citations · 846 across the 16 of their papers we have counts for
18 papers
On the Convergence of Success Conditioning for Policy Optimization
Matthew Brun, Xu Andy Sun
Success conditioning is a strategy for improving decision-making policies in stochastic environments; it updates a policy by increasing the probability of taking actions that yield…
Modeling Adversarial Wildfires for Power Grid Disruption
Matthew Brun, Xu Andy Sun, Jean-Paul Watson
Electric power infrastructure faces increasing risk of damage and disruption due to wildfire. Operators of power grids in wildfire-prone regions must consider the potential impacts…
Nonlinear conjugate gradient methods: worst-case convergence rates via computer-assisted analyses
Shuvomoy Das Gupta, Robert M. Freund, Xu Andy Sun +1
We propose a computer-assisted approach to the analysis of the worst-case convergence of nonlinear conjugate gradient methods (NCGMs). Those methods are known for their generally g…
On Distributionally Robust Multistage Convex Optimization: Data-driven Models and Performance
Shixuan Zhang, Xu Andy Sun
This paper presents a novel algorithmic study with extensive numerical experiments of distributionally robust multistage convex optimization (DR-MCO). Following the previous work o…
Recent Developments in Security-Constrained AC Optimal Power Flow: Overview of Challenge 1 in the ARPA-E Grid Optimization Competition
Ignacio Aravena, Daniel K. Molzahn, Shixuan Zhang +12
The optimal power flow problem is central to many tasks in the design and operation of electric power grids. This problem seeks the minimum cost operating point for an electric pow…
An ADMM-based Distributed Optimization Method for Solving Security-Constrained AC Optimal Power Flow
Amin Gholami, Kaizhao Sun, Shixuan Zhang +1
In this paper, we study efficient and robust computational methods for solving the security-constrained alternating current optimal power flow (SC-ACOPF) problem, a two-stage nonli…
On Distributionally Robust Multistage Convex Optimization: New Algorithms and Complexity Analysis
Shixuan Zhang, Xu Andy Sun
This paper presents an algorithmic study and complexity analysis for solving distributionally robust multistage convex optimization (DR-MCO) problems. Our main contribution is a no…
A Fast Certificate for Power System Small-Signal Stability
Amin Gholami, Xu Andy Sun
Swing equations are an integral part of a large class of power system dynamical models used in rotor angle stability assessment. Despite intensive studies, some fundamental propert…
Stochastic Dual Dynamic Programming for Multistage Stochastic Mixed-Integer Nonlinear Optimization
Shixuan Zhang, Xu Andy Sun
In this paper, we study multistage stochastic mixed-integer nonlinear programs (MS-MINLP). This general class of problems encompasses, as important special cases, multistage stocha…
Solvability of Power Flow Equations Through Existence and Uniqueness of Complex Fixed Point
Bai Cui, Xu Andy Sun
Variations of loading level and changes in system topological property may cause the operating point of an electric power systems to move gradually towards the verge of its transmi…
Towards Resilient Operation of Multi-Microgrids: An MISOCP-Based Frequency-Constrained Approach
Amin Gholami, Xu Andy Sun
High penetration of distributed energy resources (DERs) is transforming the paradigm in power system operation. The ability to provide electricity to customers while the main grid…
A New Voltage Stability-Constrained Optimal Power Flow Model: Sufficient Condition, SOCP Representation, and Relaxation
Bai Cui, Xu Andy Sun
A simple characterization of the solvability of power flow equations is of great importance in the monitoring, control, and protection of power systems. In this paper, we introduce…
Matrix Minor Reformulation and SOCP-based Spatial Branch-and-Cut Method for the AC Optimal Power Flow Problem
Burak Kocuk, Santanu S. Dey, X. Andy Sun
Alternating current optimal power flow (AC OPF) is one of the most fundamental optimization problems in electrical power systems. It can be formulated as a semidefinite program (SD…
Multistage Robust Unit Commitment with Dynamic Uncertainty Sets and Energy Storage
Alvaro Lorca, Xu Andy Sun
The deep penetration of wind and solar power is a critical component of the future power grid. However, the intermittency and stochasticity of these renewable resources bring signi…
New Formulation and Strong MISOCP Relaxations for AC Optimal Transmission Switching Problem
Burak Kocuk, Santanu S. Dey, X. Andy Sun
As the modern transmission control and relay technologies evolve, transmission line switching has become an important option in power system operators' toolkits to reduce operation…
Strong SOCP Relaxations for the Optimal Power Flow Problem
Burak Kocuk, Santanu S. Dey, X. Andy Sun
This paper proposes three strong second order cone programming (SOCP) relaxations for the AC optimal power flow (OPF) problem. These three relaxations are incomparable to each othe…
A Cycle-Based Formulation and Valid Inequalities for DC Power Transmission Problems with Switching
Burak Kocuk, Hyemin Jeon, Santanu S. Dey +3
It is well-known that optimizing network topology by switching on and off transmission lines improves the efficiency of power delivery in electrical networks. In fact, the USA Ener…
Inexactness of SDP Relaxation and Valid Inequalities for Optimal Power Flow
Burak Kocuk, Santanu S. Dey, X. Andy Sun
It has been recently proven that the semidefinite programming (SDP) relaxation of the optimal power flow problem over radial networks is exact under technical conditions such as no…