arXiv subjects

Rodrigo Ramos

Publications and source records attributed to Rodrigo Ramos.

3 recordsLinked to original sources

arXiv2022

Day-ahead Schedule Considering the Participation of Electric Vehicles in Primary Frequency Response

The insertion of renewable sources in power systems may cause a decrease in the system's equivalent inertia, which result in the instability of the power system. On the other hand, energy storage systems have proven to be an effective tool to increase the flexibility in the operation of energy systems, which may favor integrating renewable energy sources. In this way, plug-in electric vehicle (PEVs) batteries can be used as storages when such vehicles are parked and connected to the grid. In this work, the contribution of PEVs to primary frequency response is analyzed in systems dominated by renewable sources. A day-ahead scheduling model is developed considering PEVs groups can actively participate in electricity markets, supporting day-ahead reserve capacity and providing primary frequency response. The proposed model is implemented in the distribution system of the Federal University of Amap\'a.

eess.SY↗

arXiv2021

An approach for the aggregation of power system controllers with different topologies

This paper proposes an approach to aggregate nonstructured power system controllers preserving the dynamical characteristics of the original devices. The method is based on linear operations that use the frequency response of the elements, resulting in an accurate input-output description of the equivalent controller when compared to the original ones. The developed method was applied to a model of the future interconnected Paraguayan-Argentinean power system to produce a dynamic equivalent used in a real-time simulator to test the special protection scheme needed for the safe operation of the this future system. Transient and small-signal stability studies presented matching simulation results in the time domain with significantly reduced computational burden and processing time.

eess.SY↗

arXiv2018

P3HT-Fullerene Blends: a Classical Molecular Dynamics Simulation

Blends of polymer and C$_{60}$-derived molecules are in the spotlight in recent years for application in organic photovoltaics, forming what is known as bulk-heterojunction active layers. The character of the heterojunction is determinant, with clear relevance of morphology and phase separation. To better understand the morphology of the systems, we present a classical molecular dynamics (CMD) simulation of polymer/fullerene (P3HT/C$_{60}$) blends, coming from different starting points, using the specifically designed Nanomol Force Field based on the Universal Force Field. We use not-so-short regioregular polymers with 30 hexyl-thiophene units ($\sim$5kg$\cdot$mol$^{-1}$ molecular weight) and, adopting a $\sim$ 1:1 mass proportion for the polymer:molecule blend, we simulate cells of $\sim$ 40 thousand atoms, at room temperature and normal pressure conditions. We find that, independently of the starting-point spatial distribution of C$_{60}$ molecules relative to P3HT chains, segregated or isotropic, the fullerene molecules show a tendency to segregate, and phase separation is the dominating regime.

cond-mat.mtrl-sci↗