Search results for "Ady"
showing 10 items of 565 documents
An Adaptive Robust Predictive Current Control for Three-Phase Grid-Connected Inverters
2011
This paper presents an adaptive robust predictive current control (RPCC) for grid-connected three-phase inverters that exhibit zero steady-state current error. The error correction is achieved by means of an adaptive strategy that works in parallel with the deadbeat algorithm, therefore preserving the typical fast response of the predictive law. The resulting control adapts to any particular L or LCL filter by estimation of the resistive part of the filter. As a variety of the RPCC class of control, it offers the best tradeoff between robustness and speed. © 2009 IEEE.
A semi-empirical multipurpose steady-state model of a fuel cell for household appliances
2013
In this paper, a multipurpose model of a proton exchange membrane fuel cell for household appliances is proposed. According to a conventional mathematical approach, the proposed model is derived from the physical and electro-chemical equations that rule the fuel cell behaviour. Differently from existing models, a parametric analysis is carried out and a few tunable parameters are accurately selected and identified. Furthermore, this paper proposes an innovative technique of unique model architecture which enables the designer to solve by himself the trade-off between complexity and accuracy on the basis of the specific applications. Three different choices could be performed by the designer…
Sensorless low Range Speed Estimation and Parameter Identification of Induction Motor Drives Devoted to Lifts Automatic Rescue Devices
2010
In this paper a sensorless rotor speed estimation and parameter identification algorithm is presented. The algorithm is designed specifically for induction motor (IM) drives devoted to automatic rescue devices (ARD) used in lifts and hoist applications. Its peculiarity is that it is based on the sinusoidal steady state mathematical model of the IM and, therefore, can be implemented on a low cost micro-controller in a simple way, however without lacking in terms of dynamic performance. It is also capable of self tuning so that no information is required about the specific IM used in the ARD drive. Finally the algorithm allows also an appreciable energy saving of the ARD when compared to olde…
Ability of Preissmann slot scheme to simulate smooth pressurisation transient in sewers
2010
Urban drainage networks are generally designed to operate in a free-surface flow condition. However, as a consequence of heavy rainfall events or network malfunctioning, filling of sewers (pressurization) and network overflowing may occur. Several softwares are commonly used to simulate floods in drainage networks and their results are usually thought to be reliable and robust. However, no specific studies have been carried out on the behaviour of these softwares during the pressurization transient. Actually, mathematical models based on the momentum equation appear to be more suitable in correctly simulating the pressurization moving jump but models based on the energy equation are much mo…
A dynamic model for MED-TVC transient operation
2017
Abstract The Multi Effect Distillation (MED) process is often proposed as a key technology for the construction of new thermal desalination plants, especially within solar-powered cogeneration schemes. With this respect, the need for transient behaviour analysis requires the development of dynamic models for the MED process. Only a few have been presented so far in the literature, in which, however, several simplifying assumptions and constrains are still limiting their potential use. The model here proposed addresses most of the aspects still limiting previous models formulations. The powerful equation-based process simulator gPROMS® was chosen for the implementation of the model, develope…
Steady-state security analysis on the transmission grid for various scenarios of wind generation in Sicily
2009
The proposed paper is part of a research aimed at assessing the impact of wind generation on the transmission grid of Sicily, second among the Italian regions for wind power installed. After describing the current state of wind energy generation in Sicily, the paper reports and comments the results of the steady-state security analysis done for various scenarios of wind penetration. For each scenario (maximum and minimum load conditions), the redistribution of power flows on the transmission network, the voltage profiles at nodes, the analysis of contingencies and losses variations are reported.
Simulation of stability and dynamics of multistage flash desalination
2011
gPROMS software was used to study the dynamics of a multistage flash desalination brine circulation system (MSF-BR) as a function of major operating parameters. Most of the previous studies focused on MSF-BR dynamic model development however; it gave very little information on dynamic response of the system to the most significant process independent parameters. The present model was first validated against available industrial data of different plants. System dynamics were obtained upon increasing/decreasing several of the operating parameters over a range of ± 15%. Results show that increase/decrease of the cooling seawater flow rate have limited effect on the system dynamics. Increasing/…
CFD simulations of dense solid–liquid suspensions in baffled stirred tanks: Prediction of solid particle distribution
2013
Abstract Industrial tanks devoted to the mixing of solid particles into liquids are often operated at an impeller speed N less than Njs (defined as the lowest speed allowing the suspension of all particles): under such conditions the distribution of solid-particles is very far from being homogeneous and very significant concentration gradients exist. The present work is devoted to assessing the capability of Computational Fluid Dynamics (CFD) in predicting the particle distribution throughout the tank. The CFD model proposed by Tamburini et al. [58] and successfully applied to the prediction of the sediment amount and shape was adopted here to simulate the particle distribution under partia…
Steady State and Dynamic Models of Multistage Flash Desalination: A Review
2010
This article focuses on a review of literature studies on steady state and dynamic modeling of the multistage flash desalination process (MSF). The review shows that both steady state and dynamic models are based on lumped parameter approach. Differences in literature models are found in the assumptions used to model the flashing stage in addition to the correlations used to determine the heat transfer coefficients, thermodynamic losses, thermodynamic and transport properties. Interestingly, literature indicates a rapid progress made in software used for coding and solution of the model equations. The review shows a limited number of literature models for the internals of the flashing stage…
Engineering design and steady state thermomechanical analysis of the IFMIF European lithium target system
2013
In the framework of the current IFMIF Engineering Validation and Engineering Design Activities (IFMIF/EVEDA) phase, ENEA is responsible for the design of the European concept of the IFMIF lithium target system which foresees the possibility to periodically replace only the most irradiated and thus critical component (i.e., the backplate) while continuing to operate the rest of the target for a longer period (bayonet backplate concept). In this work, the results of the steady state thermomechanical analysis of the IFMIF EU target assembly are briefly reported highlighting the relevant indications obtained with respect to the fulfillment of the design requirements. © 2013 IEEE.