Browsing by Subject "Distributed Energy Resources"

Now showing 1 - 3 of 3
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    Control Paradigms For Distributed Energy Resources (Ders) To Engineer Inertial And Primary Frequency Response In Power Grids
    (2020-02) Guggilam, Swaroop
    Power networks have to withstand a variety of disturbances that affect system frequency, and the problem is compounded with the increasing integration of intermittent renewable generation. Following a large-signal generation or load disturbance, system frequency is arrested, leveraging primary frequency control provided by governor action in synchronous generators. This work proposes a framework for distributed energy resources (DERs) deployed in transmission and distribution networks to provide (supplemental) inertial and primary frequency response. This work is divided into two parts, transmission and distribution level design process. Particularly, we demonstrate how synthetic inertia and power-frequency droop slopes for individual DERs can be designed so that the system frequency conforms to prescribed transient and steady-state performance specifications at the transmission level and the distribution feeder presents guaranteed frequency-regulation characteristics at the feeder head. Furthermore, the droop and inertial coefficients are engineered such that injections of individual DERs conform to a well-defined fairness objective that does not penalize them for their location on the distribution feeder. At the transmission level, our approach is grounded in a second-order lumped-parameter model that captures the dynamics of synchronous generators, and frequency-responsive DERs endowed with inertial and droop control. A key feature of this reduced-order model is that its parameters can be related to those of the originating higher-order dynamical model. This allows one to systematically design the DER inertial and droop-control coefficients leveraging classical frequency-domain response characteristics of second-order systems. At the distribution level, the approach we adopt leverages an optimization-based perspective and suitable linearizations of the power-flow equations to embed notions of fairness and information regarding the physics of the power flows within the distribution network into the droop slopes. This optimization-based method is centered around classical economic dispatch. The accuracy of the model-reduction method and demonstration of how DER controllers can be designed to meet steady-state-regulation and transient-performance specifications for an illustrative network composed of a combined transmission and distribution network with frequency-responsive DERs is also presented.
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    Distributed Coordination and Control -- A bottom up design framework for Highly Renewable Grids and
    (2021-07) Patel, Sourav
    The modern power grid is undergoing an inflection point where the role of distributed energy resources (DERs) including renewable energy sources (RESs) has surpassed parity with conventional bulk power generation system as the prevalent source of energy generation. This transition from the conventional to modern power grids is also favored by economies of integrating distributed generation technologies, proliferation of intelligent communication devices such as sensors and data acquisition systems providing a global and persistent view into the state of the power system and, low footprint computational devices that have accelerated the distributed nature of the coordination of these DER units and if desired, to appear as a single aggregated unit to leverage the benefits of scale that a large centralized bulk power system can provide. Most of the design philosophy for the power-electronics interfaced DERs and highly renewable grid has been developed keeping in mind the operation of a conventional power system which is a large inertial system and highly centralized in nature. The existing grid needs to undergo transformations including control design methodologies keeping DERs and RESs at the focus and utilization of distributed communication algorithms at DERs allowing renewable energy resources and battery energy storage systems to participate in grid interactive services that can meet aggressive response timescales to maintain the operation and stability of the power system. This thesis makes several contributions, firstly towards enabling better active and harmonic power sharing in multi-inverter microgrid systems (MMGs) with DERs interfaced with low-inertia voltage source inverters (VSIs) while reducing the complexity of reactive power sharing and control. Secondly, investigations and contributions towards developing a novel aggregation strategy and implementation methodology for smaller DER units for enabling challenging grid interactive services in presence of real-world non-idealities such as time delay in communication channel are also presented and validated by developing a novel end-to-end power-hardware-in-the-loop (PHIL) configuration. The finite-time termination distributed schemes suffer from vulnerability to cyber-attacks that are aimed at manipulating data and control flow. In the final part we develop a novel distributed method for detecting the presence of such intruders for a multi-agent system implementing ratio consensus protocol.
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    Looking Beyond Demand Response: Barriers and Opportunities to Deploying Virtual Power Plants among Rural Electric Cooperatives in the United States
    (2024-05-16) Datta, Mayukh K.
    Rural electric cooperatives (co-ops) find themselves in a unique position regarding deploying virtual power plants. Co-ops, which are consumer-owned utilities, have a vast history of deploying controllable demand-side management technologies that can fit perfectly into a VPP framework, with almost a gigawatt of demand-side management capacity across four generation and transmission cooperatives in Minnesota (G. Chan et al. 2019; Matthew Grimley and Chan 2023). This more than forty-year-long experience deploying controllable resources and their nonprofit, consumer-owned structure makes rural electric cooperatives perfectly positioned to deploy virtual power plants. However, several challenges, such as high upfront costs and uncertainties around market rules, hinder VPP deployment for rural co-ops. Furthermore, the fact that most co-ops comprise a complex network of distribution cooperatives that make up larger generation and transmission (G&T) cooperatives also complicates how VPPs can be deployed by rural coops.