Search results for "Energy engineering"
showing 10 items of 1099 documents
Economic evaluation of PV system for EV charging stations: Comparison between matching maximum orientation and storage system employment
2016
This article addresses the problem of the choice of a generation system to be implemented to reduce the impact of charging electric vehicles at University. Based on the behaviour of the student population, it is identified the electrical load. Two possible solutions are evaluated in order to manage the peak load: an orientation of the panels in order to increase the power at defined time and the use of storage system. The main strength and weakness points of two systems are investigated by taking into account the Levelized Cost of Energy.
Electrostatic synchronous generator model of an Inverter-Based Distributed Generators
2015
In this paper, the idea of modelling the Inverter-Based Distributed Generators by using the concept of Electrostatic synchronous machines is discussed. A mathematical model of the inverter has been established which depends on the dc bus voltage, modulation index and frequency of the system. Two mathematical models have been developed: a small signal model and a steady-state model. These mathematical models will be helpful in studying the stability of a microgrid; especially when studying the transient stability performance of on-grid operation of converter-based distributed generator with multi-machine microgrid. Simulation results using Matlab/Simulink are carried out.
Optimal Electrical Distribution Systems Reinforcement Planning Using Gas Micro Turbines by Dynamic Ant Colony Search Algorithm
2007
Distribution systems management is becoming an increasingly complicated issue due to the introduction of new energy trading strategies and new technologies. In this paper, an optimal reinforcement strategy to provide reliable and economic service to customers in a given time frame is investigated. In the new deregulated energy market and considering the incentives coming from the political and economical fields, it is reasonable to consider distributed generation (DG) as a viable option for systems reinforcement. In the paper, the DG technology is considered as a possible solution for distribution systems capacity problems, along several years. Therefore, compound solutions comprising the i…
Service restoration in compensated distribution networks using a hybrid genetic algorithm
1998
In this paper a genetic algorithm (GA) based approach to the service restoration (SR) problem in automated distribution networks is presented. Normal operation within the network comprises both automatic reconfiguration and compensation so as to reduce power losses, allow load balancing and improve the voltage profile. In the restorative state, the reconfiguration is performed together with compensation, taking mainly into account the load supply requirement and secondarily, the losses reduction requirement. After a general discussion on the restoration problem together with a short review of recent papers on the topic, a solution strategy is proposed. Then, a short account about classical …
A Multi-Objective Approach to Optimize a Periodic Maintenance Policy
2012
The present paper proposes a multi-objective approach to find out an optimal periodic maintenance policy for a repairable and stochastically deteriorating multi-component system over a finite time horizon. The tackled problem concerns the determination of the system elements to replace at each scheduled and periodical system inspection by ensuring the simultaneous minimization of both the expected total maintenance cost and the expected global system unavailability time. It is assumed that in the case of system elements failure they are instantaneously detected and repaired by means of minimal repair actions in order to rapidly restore the system. A nonlinear integer mathematical programmi…
ECONOMIC-STATISTICAL DESIGN APPROACH FOR A VSSI X-BAR CHART CONSIDERING TAGUCHI LOSS FUNCTION AND RANDOM PROCESS SHIFTS
2014
Economic design approaches of control charts are commonly based on the assumption that various cost parameters values and the occurrence risk of assignable causes have to be a priori known with precision. However, in real operative contexts, such parameters can be really difficult to accurately estimate, especially considering costs arising from out-of-control conditions of the process. As consequence, pure economic design approaches can involve chart schemes with low statistical performance. To overcome such limitation, it is herein proposed a multi-objective economic-statistical design approach for an adaptive X-bar chart. In particular, such approach aims at the minimization of both the…
EABOT – Energetic analysis as a basis for robust optimization of trigeneration systems by linear programming
2008
Abstract The optimization of synthesis, design and operation in trigeneration systems for building applications is a quite complex task, due to the high number of decision variables, the presence of irregular heat, cooling and electric load profiles and the variable electricity price. Consequently, computer-aided techniques are usually adopted to achieve the optimal solution, based either on iterative techniques, linear or non-linear programming or evolutionary search. Large efforts have been made in improving algorithm efficiency, which have resulted in an increasingly rapid convergence to the optimal solution and in reduced calculation time; robust algorithm have also been formulated, ass…
Energy and Network Models for the Intelligent Control of Distributed Systems
2014
This paper presents detailed energy and network models for the intelligent control of a distributed system which also comprises power generation from renewables. The two models provide interactive energy monitoring, intelligent control and power demand balancing at home, block and neighbor level. Particularly, it is here described how the energy model works and also details of how it has been validated are here given. Moreover, it is shown how the energy model simulation results are transferred to the network simulation software SynerGEE, set up by GL Noble Denton Industrial Services Ltd (UK), in order to fully perform network simulations.
Risk Assessment of a compound feed process based on HAZOP analysis and linguistic terms
2016
[EN] The size and complexity of industrial plants, along with the characteristics of the products used, require a study, analysis and control of the existing risks in every industrial process. In this paper, a methodology for risk assessment in industrial plants, based on the combination of risks identification through the Hazard and Operability (HAZOP) analysis and the risks evaluation through linguistic variables and fuzzy numbers is applied to a case study consisting on a compound feed plant located in the town of Silla (Valencia, Spain). The results from this study show that the main risk in the compound feed production process is the formation of explosive atmospheres (ATEX). Therefore…
Nonlinear droop control for minimum power losses operation in islanded microgrids
2017
In this work, a modified primary regulation technique is proposed to control one of the inverter interfaced units feeding an islanded microgrid. The proposed approach employs an off-line minimum losses Optimal Power Flow, OPF, to extract a lookup table for the composition of the droop curve. Simulations prove that generators reach an operating point that corresponds to a minimum loss operation for the relevant power flow distribution. Since OPF has been implemented with frequency and voltage dependent models, the results of the modified droop are stable and also energy efficient. Further studies will address further analysis on systems showing different R/X ratio and modeling of more genera…