Search results for "Power System"
showing 10 items of 322 documents
Applicational Aspects of a New Diagnostic Methodology for Fault Location in MV Networks: Problems, Solutions and Improvements
2005
The electrical energy market liberalization has encouraged utilities to make new investments at distribution level so as to attain higher quality levels. Service continuity is one of the aspects of greater importance in the definition of the quality of the electrical energy, for this reason, the research in the field of faults diagnostic for distribution systems is spreading ever more. The Authors have just developed a new methodology for diagnostic management of automated distribution systems. The technique is based on the use of circuital models of the electrical system resulting from the composition of quadripoles. In this paper, after a brief description of the proposed approach, the is…
Optimization of photovoltaic energy production through an efficient switching matrix
2013
This work presents a preliminary study on the implementation of a new system for power output maximization of photovoltaic generators under non-homogeneous conditions. The study evaluates the performance of an efficient switching matrix and the relevant automatic reconfiguration control algorithms. The switching matrix is installed between the PV generator and the inverter, allowing a large number of possible module configurations. PV generator, switching matrix and the intelligent controller have been simulated in Simulink. The proposed reconfiguration system improved the energy extracted by the PV generator under non-uniform solar irradiation conditions. Short calculation times of the pro…
Economic analysis on dynamic photovoltaic systems in new Italian “feed in tariffs” context
2013
Dynamic photovoltaic generators, based on the application of solar-trackers, are able to give an increment to the electric energy production from solar source. Their realization and maintenance costs are certainly higher than those of fixed ones. In this paper the Authors propose a method to estimate the increment of electrical energy generation that must be guaranteed by a dynamic photovoltaic generator, so as its realization could be more favorable with respect to that of a fixed generator one with the same rated power. This method, developed by means of classical economic indexes like the Pay-Back-Period and the Net Present Value, takes in to account the economic incentives for the PV sy…
Heuristic-Based Shiftable Loads Optimal Management in Smart Micro-Grids
2015
In this paper, an optimal power dispatch problem on a 24-h basis for distribution systems with distributed energy resources (DER) also including directly controlled shiftable loads is presented. In the literature, the optimal energy management problems in smart grids (SGs) where such types of loads exist are formulated using integer or mixed integer variables. In this paper, a new formulation of shiftable loads is employed. Such formulation allows reduction in the number of optimization variables and the adoption of real valued optimization methods such as the one proposed in this paper. The method applied is a novel nature-inspired multiobjective optimization algorithm based on an original…
Photovoltaic based active generator: Energy control system using stateflow analysis
2015
At present, most of the grid connected photovoltaic (PV) systems are operating at maximum power points and injecting power in uncontrolled way. Thus, active generator will be a good solution to support instantaneous power balance, frequency control and maintaining the power quality with controllable power injection. This new mode of active generator needs innovative power management. The new proposed energy control system for active generator might help to manage the energy within the micro-grid environment. In this work, the focus is to manage the energy among the PV based active generator, load and interconnected grid and energy controller architecture for that purpose is presented. It co…
A new modified Inc-Cond MPPT technique and its testing in a whole PV simulator under PSC
2015
In this paper a new modified Inc-Cond MPPT technique able to lead PV plants to work in the real MPP (Maximum Power Point) under PSC (Partial Shading Condition) is proposed. The new Inc-Cond MPPT technique working principle is fully explained, discussed and then successfully tested in a whole and reliable PV simulator conceived and set-up by the Authors in order to test and compare several new MPPT algorithms. The simulation results show that the proposed Inc-Cond MPPT technique is able to successfully lead the PV plant to work in the real MPP both in the cases of instantaneous and gradual changing of shading and of temperature conditions.
Photovoltaic plant array reconfiguration: Design of a new device
2014
An efficient strategy to improve unequally irradiated PV plants performances is based on the reconfiguration of the connections between the modules. In this paper, an algorithm, for this purpose conceived, is presented. Moreover, the design, realization and finally also the set up of a new reconfiguration system device is fully shown and discussed. The algorithm conceived simulates several possible series-parallel connections under varying irradiation conditions, and determines the optimal modules connection in order to get the maximum output power. In this way, the reconfiguration system may set up the reconfiguration strategy. The reconfiguration system prototype set up, basically consist…
Achieving maximum power transfer in a multi-source renewable system
2014
In this paper, a multi-source DC-DC power system is proposed for renewable applications. A multi-input, single inductor power converter controlled by two interacting control loops is designed. The steady-state and small-signal analysis of the designed system is carried out. A battery-photovoltaic system is designed as an application example. Both the output voltage and maximum power point of solar panels are properly controlled to achieve high performances of the whole system. Experimental results on a 48 V laboratory prototype are presented to discuss system performances.
Measurement Issues for the Characterization of Medium Voltage Grids Communications
2013
This paper is focused on the measurement issues and procedures for the characterization of medium voltage grids for narrowband power line communications (NB-PLCs), in the perspective of the use and integration of such technology into smart grids communication networks. The fundamentals are given for the characterization of the PLC channel, by means of noise and attenuation measurements. Suitable procedures are also developed for the characterization and modeling of the power system components in the frequency range of interest. Furthermore, the complete model of the PLC system is experimentally validated in a real case study.
NARX Models of an Industrial Power Plant Gas Turbine
2005
This brief reports the experience with the identification of a nonlinear autoregressive with exogenous inputs (NARX) model for the PGT10B1 power plant gas turbine manufactured by General Electric-Nuovo Pignone. Two operating conditions of the turbine are considered: isolated mode and nonisolated mode. The NARX model parameters are estimated iteratively with a Gram-Schmidt procedure, exploiting both forward and stepwise regression. Many indexes have been evaluated and compared in order to perform subset selection in the functional basis set and determine the structure of the nonlinear model. Various input signals (from narrow to broadband) for identification and validation have been consider…