Search results for "electrical"
showing 10 items of 11048 documents
Optimization of BESS Capacity Under a Peak Load Shaving Strategy
2018
Battery energy storage systems (BESSs) are becoming increasingly competitive in the global energy landscape, thanks to the strong cost reduction that has taken place in recent years and it is expected to continue in the next future. Among the many benefits BESSs can provide, time shifting can be exploited by electricity consumers to save on the electricity bill, charging the storage during the off-peak hours and discharging when the cost of electricity is high. This paper describes a simple procedure to optimize the BESS capacity under a peak load shaving strategy, in presence of a time-of-use (TOU) electricity rate, able to guarantee, at the same time, the flattest daily power diagram and …
DEMAND Project: A Peak Load Shaving Strategy for End-User Consumers
2018
Battery energy storage systems (BESS) are becoming increasingly widespread in modern power systems, thanks to the important benefits they can provide to the electricity grid. Indeed, BESS can be used in time shifting applications, storing energy during off-peak periods and discharging during peak times (when the cost of electricity is high). When BESS are used for peak shaving purposes, they also contribute to relieve peak demand charges, thus ensuring a saving for the consumers. This paper describes a peak load shaving strategy defined within the DEMAND project. The strategy is able to guarantee the flattest daily power diagram and the maximum benefit for the electricity consumers, reducin…
Iterative Learning Applied to Hydraulic Pressure Control
2018
This paper addresses a performance limiting phenomenon that may occur in the pressure control of hydraulic actuators subjected to external velocity disturbances. It is demonstrated that under certain conditions a severe peaking of the control error may be observed that significantly degrades the performance of the system due to the presence of nonlinearities. The phenomenon is investigated numerically and experimentally using a system that requires pressure control of two hydraulic cylinders. It is demonstrated that the common solution of feed forwarding the velocity disturbance is not effective in reducing the peaking that occurs as a result of this phenomenon. To improve the system perfor…
A Complete, Exact and Efficient Implementation for Computing the Edge-Adjacency Graph of an Arrangement of Quadrics
2011
International audience; We present a complete, exact and efficient implementation to compute the edge-adjacency graph of an arrangement of quadrics, i.e. surfaces of algebraic degree 2. This is a major step towards the computation of the full 3D arrangement. We enhanced an implementation for an exact parameterization of the intersection curves of two quadrics, such that we can compute the exact parameter value for intersection points and from that the edge-adjacency graph of the arrangement. Our implementation is complete in the sense that it can handle all kinds of inputs including all degenerate ones, i.e. singularities or tangential intersection points. It is exact in that it always comp…
Inverse estimation of the cardiac purkinje system from electroanatomical maps
2020
Las enfermedades cardiovasculares son la primera causa de mortalidad en el mundo, con 17.7 millones de muertes cada año, aproximadamente el 31% de las muertes en todo el mundo (Organización Mundial de la Salud (OMS) 2018). Las arritmias ventriculares son una causa importante de muerte súbita, que representa aproximadamente la mitad de la mortalidad cardíaca. Algunas de esas arritmias se atribuyen a la red de Purkinje (PKN), que bajo ciertas condiciones puede generar ritmos focales automáticos, y su configuración de red puede sostener circuitos eléctricos reentrantes. Los ritmos focales originados desde la red de Purkinje pueden servir como puntos de inicio en casos de fibrilación ventricula…
The Effect of the Range of a Modulating Phase Mask on the Retrieval of a Complex Object from Intensity Measurements
2021
The authors have been supported by the postdoctoral project (1.1.1.2/16/I/001, 1.1.1.2/VIAA/1/16/199), the CAMART2 project (grant agreement ID 739508), the Latvian Investment and Development Agency (LIDA) project (KC-PI-2017/105), and the grant for the Latvian State Emeritus Scientists.
Experimental test of the performances of a photovoltaic modules model
2015
In this paper, a measurement-based modeling technique for PV panels oriented to power electronics design is proposed. The proposed modelling approach aims at an accurate modeling of the whole PV curve and not only around a few remarkable points. The proposed approach is based on an experimental characterization of the module under test. In fact, the incompleteness of manufacturers' data and the knowledge of physical parameters are the main source of inaccuracy in existing modelling approaches. The proposed approach is applied to a four lumped parameters model of a Conergy E215P solar module. Tests are performed under natural light. The parameter identification procedure is described in deta…
Extending the Power Range of a Solar Inverter
2018
Solar inverters feature a minimum and maximum limit of the maximum power point voltage. Overcoming these limits leads to a disconnection of the power equipment, thus wasting the solar energy. In this paper, a solution to extend the power range of a solar inverter is presented. The proposed solution extends he minimum maximum power point limit of a commercial solar inverter by means of a battery energy storage system, including a DC/DC power converter. The battery energy storage system is connected in series to the photovoltaic module. If the photovoltaic module voltage drops below the minimum maximum power point limit, the battery energy storage system is enabled thus boosting the input vol…
Numerical procedures and their practical application in PV module analyses. Part III: parameters of atmospheric transparency – determining and correl…
2023
The presented article examines aspects of a PV module testing using natural sunlight in outdoor conditions. The article discusses the physical sense of indexes: atmosphere purity, diffused component content, beam clear sky index. Procedures for their determination are given in relation to both instantaneous and daily values. Their close connection with the values of solar irradiance spectral distribution such as Average Photon Energyand Useful Fractionis demonstrated, as well as their usefulness in moduletesting in outdoor conditions. Their influence on the conversion of modules made from various absorbers and various technologies is demonstrated
Subjective stress, objective heart rate variability-based stress, and recovery on workdays among overweight and psychologically distressed individual…
2015
Background: The present study aimed to investigate how subjective self-reported stress is associated with objective heart rate variability (HRV)-based stress and recovery on workdays. Another aim was to investigate how physical activity (PA), body composition, and age are associated with subjective stress, objective stress, and recovery. Methods: Working-age participants (n = 221; 185 women, 36 men) in this cross-sectional study were overweight (body mass index, 25.3-40.1 kg/m(2)) and psychologically distressed (>= 3/12 points on the General Health Questionnaire). Objective stress and recovery were based on HRV recordings over 1-3 workdays. Subjective stress was assessed by the Perceived St…