Search results for "Electric power system"
showing 10 items of 169 documents
Numerical Analysis of Medium Scale PV Plants and Their Power-Flow Control System With a Simple Three Phase Inverter
2012
This paper presents a mathematical analysis of a medium scale Photovoltaic (PV) power generation system connected to the distribution network and of its control system, in which the conversion stage is unique thanks to the absence of a boost chopper. Boost choppers are usually used as actuator for maximum power point tracking (MPPT). The conducted analysis leads to the conclusion that the used inverter presents two degrees of freedom that can be easily exploited in a control system in which the inverter simultaneously realizes the interconnection to the grid and at the same time realizes the MPPT control. The structure of the control system is then presented, discussed and then validated by…
Uprating an Overhead Line. Italian TSO Applications for Integration of RES
2013
The increase of Renewable Energy Sources (RES) production units has caused significant changes in the electrical system configuration. The existing structural asset isn't adequate to dispatch these new power flows that, at same time, should be favorite by various TSOs in order to obtain incentives. The outage of primary substations on the grid and the increase of consumptions have caused growing load currents on existing overhead line. This paper, after introducing thermal resistant conductors and Dynamic Rating (DR) solutions, reports an applications used by TERNA Group S.p.A. (Italian TSO). These systems are already installed on lines and they are contributing to increase power flows than…
A suitable control technique for fault-tolerant converters in Distributed Generation
2011
The penetration of Distributed Generation (DG) in power systems is deeply changing the existing distribution networks which is becoming a very sophisticated and complex systems incorporating both active (generators) and passive systems (distribution systems, converters and loads). The necessary simplification can be obtained dealing with small networks, namely Micro-Grids, reproducing, in a smaller scale, the structure and the problems of large networks including production, transmission and distribution of the electrical energy. In order to achieve an adequate level of reliability, fault-tolerant operations of micro-grids become very important. This result can be achieved only using power …
A New Device for the Control and the Connection to the Grid of Combined RES-based Generators and Electric Storage Systems
2013
In this paper a new device for the control and the connection to the supply utility grid of combined RES-based generators and electric storage systems is presented. The device is a bidirectional converter that can be controlled so as to facilitate the interface between the low voltage grid and photovoltaic or wind generators combined with batteries, contemporary addressing the requirements of the reference technical standards for users connection and providing different ancillary services. In the paper the functioning of the device and its circuit diagram are described, the single parts are shown and the potentiality of its control system are commented. © 2013 IEEE.
A novel fuel cell-based power system modeling approach
2013
Nowadays, fuel cells are the most promising source of energy for stationary applications. Unfortunately, the power density of fuel cells is not adequate for modern applications. A fuel cell - based hybrid power supply is required. The fuel cell is coupled with a high-energy density power source to improve performances of the composite power source. A power management stage is introduced between the two basic sources to control the power flow path from the fuel cell to the auxiliary source and the load. In order to avoid effects of a limited power density of the fuel cell on the whole power supply, sophisticated power management algorithms are implemented. Accurate modeling is required to te…
Narrowband power line communications for medium voltage smart grids
2014
The aim of the paper is to show how narrowband power line communications (NB-PLCs) can be a valid solution for medium voltage grids. Advantages and drawbacks of this solution are analyzed, starting from some experimental communication results, which were carried out on the medium power system networks of the islands of Ustica and Favignana, in the presence of the net voltage. Furthermore, some communication architectures and hardware prototypes based on NB-PLCs are proposed for different smart grids applications.
Analysis of driving cycles effects on power supply requirements of a fuel cell powered light-weight electric vehicle
2015
In this paper, fuel cell powered lightweight vehicles are addressed. A MATLAB/Simulink simulation model including motor, electrical drive, the fuel cell and power electronics systems is implemented. The model is well suited to perform the driving cycle test, which reproduces the speed pattern of an electric vehicle through urban, rural or motorway routes. This paper aims at investigating the most suited driving cycle to design high performances hybrid power supply for electric vehicles in terms of cruising range, cost and size of the power supply equipment. For this purpose, a legislative and a real-world driving cycles are selected. Effects of driving cycles on the power system requirement…
Impact of integrating photovoltaic based DG on distribution network harmonics
2017
The process of integrating various distributed generation (DG) technologies in power system networks is increasing rapidly in the recent years. One major concern about the integration of DGs is their impact on network harmonics. The aim of this paper is to investigate the effects caused by the integration of photovoltaic DG in distribution networks on system harmonics. The penetration level, number of DG units, and their location are used as parameters in order to verify the effects of DG on system harmonics. Moreover, a study of single and double tuned filters is conducted as harmonics mitigation techniques. Detailed simulations using Matlab/Simulink are inserted in order to explain and ve…
Urban Energy Hubs and Microgrids: Smart Energy Planning for Cities
2017
In this chapter, we try to connect the urban design features with energy consumption and consequent pollution parameters. After a review of a selected set of approaches to Urban Energy Systems study with a special focus on electrical power systems, urban energy systems are proposed as networks of multi-source hybrid energy hubs, where different energy flows are collected at the same bus and can be stored, delivered or transformed as needed. Resources at the hub and infrastructures interact with each other; therefore, both definition and boundaries of such energy systems at urban level are difficult to be clearly outlined. Similarly, the possibility to generate new operational models based o…
A Technique for Power Supply Harmonic Impedance Estimation Using a Controlled Voltage Disturbance
2002
A method for power system impedance estimation is presented. The method employs a power converter to inject a voltage transient onto the supply system. As the technique employs controlled power electronic devices it may be used as a stand alone piece of a portable measurement equipment, or it may be embedded into the functions of an active shunt filter for improved harmonic control. The impedance is estimated through correlation of the measured voltage and current transients. Simulations and experimental results demonstrate the measurement technique is highly accurate and effective.