Publications (29)
The role of convexity on saddle-point dynamics: Lyapunov function and robustness
Ashish Cherukuri, Enrique Mallada, Steven Low +1
This paper studies the projected saddle-point dynamics associated to a convex-concave function, which we term saddle function. The dynamics consists of gradient descent of the sadd…
The Role of a Market Maker in Networked Cournot Competition
Subhonmesh Bose, Desmond Cai, Steven Low +1
We study the role of a market maker (or market operator) in a transmission constrained electricity market. We model the market as a one-shot networked Cournot competition where gen…
Solving the power flow equations: a monotone operator approach
Krishnamurthy Dvijotham, Steven Low, Michael Chertkov
The AC power flow equations underlie all operational aspects of power systems. They are solved routinely in operational practice using the Newton-Raphson method and its variants. T…
Risk-Sensitive Online Algorithms
Nicolas Christianson, Bo Sun, Steven Low +1
We study the design of risk-sensitive online algorithms, in which risk measures are used in the competitive analysis of randomized online algorithms. We introduce the CVaR-com…
Distributed Optimal Frequency Control Considering a Nonlinear Network-Preserving Model
Zhaojian Wang, Feng Liu, John Z. F. Pang +2
This paper addresses the distributed optimal frequency control of power systems considering a network-preserving model with nonlinear power flows and excitation voltage dynamics. S…
Convexity of Energy-Like Functions: Theoretical Results and Applications to Power System Operations
Krishnamurthy Dvijotham, Steven Low, Michael Chertkov
Power systems are undergoing unprecedented transformations with the incorporation of larger amounts of renewable energy sources, distributed generation and demand response. All the…
Decentralized Parametric Stability Certificates for Grid-Forming Converter Control
Verena Häberle, Xiuqiang He, Linbin Huang +2
We propose a decentralized framework to analytically guarantee the small-signal stability of future power systems with grid-forming converters. Our approach leverages dynamic loop-…
Data-Driven Successive Linearization for Optimal Voltage Control
Yiwei Dong, Wenqi Cui, Han Xu +2
Power distribution systems are increasingly exposed to large voltage fluctuations driven by intermittent renewable generation and time varying loads (e.g., electric vehicles and st…
Decentralized Primary Frequency Control in Power Networks
Changhong Zhao, Steven Low
We augment existing generator-side primary frequency control with load-side control that are local, ubiquitous, and continuous. The mechanisms on both the generator and the load si…
Stability Constrained Reinforcement Learning for Real-Time Voltage Control
Yuanyuan Shi, Guannan Qu, Steven Low +2
Deep reinforcement learning (RL) has been recognized as a promising tool to address the challenges in real-time control of power systems. However, its deployment in real-world powe…
Reverse and Forward Engineering of Local Voltage Control in Distribution Networks
Xinyang Zhou, Masoud Farivar, Zhiyuan Liu +2
The increasing penetration of renewable and distributed energy resources in distribution networks calls for real-time and distributed voltage control. In this paper we investigate…
Uncertainty-Aware Capacity Expansion for Real-World DER Deployment via End-to-End Network Integration
Yiyuan Pan, Yiheng Xie, Steven Low
The deployment of distributed energy resource (DER) devices plays a critical role in distribution grids, offering multiple value streams, including decarbonization, provision of an…
Leveraging Predictions in Power System Voltage Control: An Adaptive Approach
Wenqi Cui, Yiheng Xie, Steven Low +2
High variability of solar PV and sudden changes in load (e.g., electric vehicles and storage) can lead to large voltage fluctuations in the distribution system. In recent years, a…
Synchrophasors and Synchrowaveforms for the Distribution Grid: The SoCal 28-Bus Dataset
Yiheng Xie, Lucien Werner, Kaibo Chen +3
We provide an open-access dataset of phasor & waveform measurement units (PMUs/WMUs) of a real-world electrical distribution network. The network consists of diverse sets of genera…
Breaking Diversity Restriction: Distributed Optimal Control of Stand-alone DC Microgrids
Zhaojian Wang, Feng Liu, Ying Chen +2
Stand-alone direct current (DC) microgrids may belong to different owners and adopt various control strategies. This brings great challenge to its optimal operation due to the diff…
Fast and Reliable Contingency Screening with Input-Convex Neural Networks
Nicolas Christianson, Wenqi Cui, Steven Low +2
Power system operators must ensure that dispatch decisions remain feasible in case of grid outages or contingencies to prevent cascading failures and ensure reliable operation. How…
Distributed Algorithm for Optimal Power Flow on Unbalanced Multiphase Distribution Networks
Qiuyu Peng, Steven Low
The optimal power flow (OPF) problem is funda- mental in power distribution networks control and operation that underlies many important applications such as volt/var control and d…
Inverse Power Flow Problem
Ye Yuan, Steven Low, Omid Ardakanian +1
This paper formulates an inverse power flow problem which is to infer a nodal admittance matrix (hence the network structure of a power system) from voltage and current phasors mea…
System Level Synthesis
James Anderson, John C. Doyle, Steven Low +1
This article surveys the System Level Synthesis framework, which presents a novel perspective on constrained robust and optimal controller synthesis for linear systems. We show how…
Event Detection and Localization in Distribution Grids with Phasor Measurement Units
Omid Ardakanian, Ye Yuan, Roel Dobbe +3
The recent introduction of synchrophasor technology into power distribution systems has given impetus to various monitoring, diagnostic, and control applications, such as system id…
Learning Optimal Power Flow: Worst-Case Guarantees for Neural Networks
Andreas Venzke, Guannan Qu, Steven Low +1
This paper introduces for the first time a framework to obtain provable worst-case guarantees for neural network performance, using learning for optimal power flow (OPF) problems a…
Optimal Inverter VAR Control in Distribution Systems with High PV Penetration
Masoud Farivar, Russell Neal, Christopher Clarke +1
The intent of the study detailed in this paper is to demonstrate the benefits of inverter var control on a fast timescale to mitigate rapid and large voltage fluctuations due to th…
Reinforcement Learning for Selective Key Applications in Power Systems: Recent Advances and Future Challenges
Xin Chen, Guannan Qu, Yujie Tang +2
With large-scale integration of renewable generation and distributed energy resources, modern power systems are confronted with new operational challenges, such as growing complexi…
A differential analysis of the power flow equations
Krishnamurthy Dvijotham, Michael Chertkov, Steven Low
The AC power flow equations are fundamental in all aspects of power systems planning and operations. They are routinely solved using Newton-Raphson like methods. However, there is…
Combining Model-Based and Model-Free Methods for Nonlinear Control: A Provably Convergent Policy Gradient Approach
Guannan Qu, Chenkai Yu, Steven Low +1
Model-free learning-based control methods have seen great success recently. However, such methods typically suffer from poor sample complexity and limited convergence guarantees. T…
Tractable Identification of Electric Distribution Networks
Ognjen Stanojev, Lucien Werner, Steven Low +1
The identification of distribution network topology and parameters is a critical problem that lays the foundation for improving network efficiency, enhancing reliability, and incre…
Equipping Black-Box Policies with Model-Based Advice for Stable Nonlinear Control
Tongxin Li, Ruixiao Yang, Guannan Qu +3
Machine-learned black-box policies are ubiquitous for nonlinear control problems. Meanwhile, crude model information is often available for these problems from, e.g., linear approx…
Design and Stability of Load-Side Primary Frequency Control in Power Systems
Changhong Zhao, Ufuk Topcu, Na Li +1
We present a systematic method to design ubiquitous continuous fast-acting distributed load control for primary frequency regulation in power networks, by formulating an optimal lo…
Running Primal-Dual Gradient Method for Time-Varying Nonconvex Problems
Yujie Tang, Emiliano Dall'Anese, Andrey Bernstein +1
This paper considers a nonconvex optimization problem that evolves over time, and addresses the synthesis and analysis of regularized primal-dual gradient methods to track a Karush…