16,647 research outputs found
Unlocking the Potential of Flexible Energy Resources to Help Balance the Power Grid
Flexible energy resources can help balance the power grid by providing
different types of ancillary services. However, the balancing potential of most
types of resources is restricted by physical constraints such as the size of
their energy buffer, limits on power-ramp rates, or control delays. Using the
example of Secondary Frequency Regulation, this paper shows how the flexibility
of various resources can be exploited more efficiently by considering multiple
resources with complementary physical properties and controlling them in a
coordinated way. To this end, optimal adjustable control policies are computed
based on robust optimization. Our problem formulation takes into account power
ramp-rate constraints explicitly, and accurately models the different
timescales and lead times of the energy and reserve markets. Simulations
demonstrate that aggregations of select resources can offer significantly more
regulation capacity than the resources could provide individually.Comment: arXiv admin note: text overlap with arXiv:1804.0389
Application of shear layer adapted sub-grid length scale in SST-IDDES
Shear layer adapted sub-grid length scale is applied in Improved Delayed Detached Eddy Simulation with SST background RANS model (SSTIDDES). The objective is to ease the “grey area” through dramatically decreasing the eddy viscosity in the initial region of a free shear layer. Two test cases including a near-sonic jet and a backward-facing step flow are tested to show the advantage of the new solution-dependent definition of sub-grid length scale over the original one in unlocking the Kelvin-Helmholtz (K-H) instability in the free shear laye
Unlocking the deployment of spectrum sharing with a policy enforcement framework
Spectrum sharing has been proposed as a promising way to increase the efficiency of spectrum usage by allowing incumbent operators (IOs) to share their allocated radio resources with licensee operators (LOs), under a set of agreed rules. The goal is to maximize a common utility, such as the sum rate throughput, while maintaining the level of service required by the IOs. However, this is only guaranteed under the assumption that all “players”respect the agreed sharing rules. In this paper, we propose a comprehensive framework for licensed shared access (LSA) networks that discourages LO misbehavior. Our framework is built around three core functions: misbehavior detection via the employment of a dedicated sensing network; a penalization function; and, a behavior-driven resource allocation. To the best of our knowledge, this is the first time that these components are combined for the monitoring/policing of the spectrum under the LSA framework. Moreover, a novel simulator for LSA is provided as an open access tool, serving the purpose of testing and validating our proposed techniques via a set of extensive system-level simulations in the context of mobile network operators, where IOs and several competing LOs are considered. The results demonstrate that violation of the agreed sharing rules can lead to a great loss of resources for the misbehaving LOs, the amount of which is controlled by the system. Finally, we promote that including a policy enforcement function as part of the spectrum sharing system can be beneficial for the LSA system, since it can guarantee compliance with the spectrum sharing rules and limit the short-term benefits arising from misbehavior
Unlocking the potential of the smart metering technology: How can regulation level the playing-field for new services in smart grids?
By integrating a communications system with the existing power grid, smart grids provide end-to-end connectivity. This enables all entities and components integrated in the electricity supply system to exchange information without knowing the network's structure. New services and applications such as demand response or virtual power plants that will aid to improve and optimize the use of electricity depend on the availability of a smart grid communication network. End-to-end communication networks require that the missing communications gap between consumers' premises and the remaining energy network is bridged by deploying an Advanced Metering Infrastructure (AMI). Given the current liberalized electricity markets' structure incumbent distribution system operators (DSOs) will control the AMI and the meter data. This gives rise to concerns about anti-competitiveness. We argue that leveraging the AMI in a social welfare maximizing way requires non-discriminatory access for all entitled parties to the (1) AMI and the (2) meter data through (3) interoperable standards. We discuss possible regulatory remedies to ensure a level playing-field for innovative services in smart grids and consider implications for research and regulation. --Regulation,Smart Grid,Smart Meter,Antitrust
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