MIT - MIT EESG Seminar Series Spring 2023

Speaker: Dr. Honghao Zheng (ComEd)
Title: Towards an Interoperable and Equitable Distribution Operation Framework
Abstract: This presentation will review several interesting ComEd Smart Grid investments in the past decade, share the learnings and hint on a series of future challenges. The topics span from distributed energy resources management system (DERMS), electric vehicle demonstration pilots, microgrid management system (MGMS), advanced sensor deployment and grid-edge intelligence.



Speaker: Prof. Mads Almassalkhi (University of Vermont)
Title: The Battle for Grid Flexibility: Control architectures, information gaps, and grid optimization
Abstract: As energy policies push electrification and renewable generation, responsive behind-the-meter DERs, such as smart thermostats, heat-pumps, EV chargers, and residential batteries, are being lifted into the ether to become part of 3rd-party aggregator platforms that can supply wholesale energy market services (as virtual power plants or VPPs) or utility services (as a retail VPP). The services are delivered by coordinating the response of DERs in (near) real-time based on changing market/grid/emission reference (power) signals (i.e., feedback). This talk will discuss different control architectures for DER coordination and the role of what is measured/estimated to enable closed-loop feedback control. In addition, as electrification efforts scale up, large-scale actuation of DERs can impact local distribution feeders, which begs the question of who is in charge of distribution grid reliability, if utilities cannot control the DERs and aggregators cannot observe the grid? The talk will discuss this asymmetry of information and propose a dynamic hosting-capacity mechanism through which utilities and aggregators can co-exist without one becoming the other or sacrificing grid reliability. Lastly, I will share some new directions from incoming projects.



Speaker: Dr. Guangya Yang (DTU)
Title: Transient stability assessment of grid following converter for offshore wind applications
Abstract: In recent years, the application of transient stability analysis methods on conventional power systems has been extended to grid-connected converters. The dynamics of converters within a certain frequency region can be modeled using two-order differential equations with similar configuration to the swing equations. This presentation will first discuss the performance of various transient stability assessment methods such as time-domain simulations, phase portrait analysis, equal-area criteria, and Lyapunov`s direct method. These methods are used to estimate the region of attraction (ROA) of a post-disturbance converter with grid-following control. However, the dynamics of the dynamic equations of converters are control parameter-dependent with time dependency due to the control actions during the post-fault disturbance period. Insights are provided into the equations and analysis is extended to include certain nonlinear and time dependency characteristics of the converter control in the ROA estimation, which is verified by time-domain simulation. At the end, the potential and challenges of nonlinear stability assessment for offshore wind power plants is discussed.



Speaker: Dr. Marcelo Elizondo (PNNL)
Title: Resilience and interregional transmission needs for the power grid transformation
Abstract: The power grid is currently undergoing a significant transformation with recently increased penetration of inverter based resources and with the expected significant changes towards zero emission energy systems. Expanding the interregional bulk transmission systems is expected to benefit the transition, in particular large HVDC transmission systems have been proposed to connect remote renewables to load centers. At the same time, the transmission system should be resilient to extreme weather events like hurricanes. In this talk, I will cover related work on interregional transmission and resilience related to hurricane events. I will cover work on HVDC transmission overlay on continental U.S. and work on studying transmission resilience in Puerto Rico with scenarios of high penetration or renewables.



Speaker: Dr. Wei Du (Pacific Northwest National Lab)
Title: Grid-Forming Inverters at Scale: A journey from a single microgrid to a bulk power system with 10,000+ inverters
Abstract: This presentation will be a journey from a single microgrid to an integrated transmission & distribution system with 10,000+ inverters. The presentation includes three parts. First, it will review the basic concepts of droop control and share the field experience on how CERTS Microgrid deals with overload events through autonomous control design. Second, it will provide a comparative study of two widely used grid-forming controls: single- and multi-loop droop controls. An insight will be provided to help understand the differences between the two widely used control strategies. EMT simulation, small signal analysis, and HIL testing will be provided to verify and explain this understanding. Finally, this presentation will share some simulation work performed on an integrated T&D co-simulation platform that has 10,000+ grid-forming and grid-following inverters leveraging the U.S. DOE invested open-source tools. The stability boundary identified through this case study will be discussed.



Speaker: Prof. Yang Weng (Arizona State University)
Title: Assured AI for Distribution Systems
Abstract: Deep penetration of distributed energy resources (DERs) calls for improved monitoring of power systems against reliability. For example, the low observability in some distribution grids makes monitoring DERs hard due to limited investment and vast coverage of distribution grids. Past methods proposed machine learning models with limited explainability. However, critical energy infrastructure needs assurance. For such a need, this talk shows how to design assured machine learning for power system monitoring via a twin structure of two learning agents, namely the AI-based and physics-guided models. The twins will collaborate adaptively to minimize the learning error while maximizing physical consistency. The structure ensures good generalization properties of the learned models. Finally, we will show how the ideas grow into several Department of Energy (DOE) projects, showing collaborations between industry and academic members. The talk will end with open future problems in distribution grids.