Search results for "Electrical & Electronic"

Arc Fault Detection Method Based on CZT Low-Frequency Harmonic Current Analysis

2017

This paper presents a method for the detection of series arc faults in electrical circuits, which has been developed starting from an experimental characterization of the arc fault phenomenon and an arcing current study in several test conditions. Starting from this, the authors have found that is it possible to suitably detect arc faults by means of a high-resolution low-frequency harmonic analysis of current signal, based on chirp zeta transform, and a proper set of indicators. The proposed method effectiveness is shown by means of experimental tests, which were carried in both arcing and nonarcing conditions and in the presence of different loads, chosen according to the UL 1699 standard…

Charging management of grid integrated battery for overcoming the intermittency of RE sources

2016

Grid integration of distributed generation (DG) systems with energy storage system can help not only in increasing the more penetration of DG systems into the network but it is also going to help in improving the power system dynamics, stability and control as well as helping in demand side management. In this work, a method for integrating an energy storage with the grid which can provide the prescribed active and reactive power to the grid is presented. The main objective is to ensure a high state of charge (SOC) of the battery with the innovative control system for taking part in power system control. Active and reactive power dispatching using a bi-directional DC-DC converters and a vol…

The Bologna Process in Academic Basic Units: Finnish Universities and Competitive Horizons

2008

Harmonic mitigation of a grid-connected photovoltaic system using shunt active filter

2017

Conventional LC filters cannot compensate effectively harmonics due to non-linear loads in a grid-connected photovoltaic (PV) system. Thus, active power filters (APF) are introduced due to its characteristics and performances, for compensation of harmonics from non-linear loads in the grid-connected photovoltaic (PV) system. This work presents a three-phase voltage-fed shunt active power filter implementation to mitigate the harmonics in which the filter control system focuses on generating reference source current for compensating harmonic effects from non-linear loads. Furthermore, the developed model is verified with an experimental data from a nonlinear load.

Identification and Experimental Validation of an Induction Motor Thermal Model for Improved Drivetrain Design

2017

The ability of an electric powertrain to perform according to mechanical specifications is equally important as assessing its thermal protection limits, which are affected by its electrical and thermal properties. Although rated parameters (such as power, torque, etc.) are easily accessible in catalogs of equipment producers, more specific properties like mass/length of copper winding, heat dissipation factor, etc., are not available to customers. Therefore, an effective selection of drivetrain components is limited due to the lack of sufficient data and the need to consult critical design decisions with suppliers. To overcome this limitation, we propose a method to estimate the temperature…

Radio measurements on a customized software defined radio module: A case study of energy detection spectrum sensing

2017

In this paper, we developed a software defined radio (SDR) system for implementing energy detection spectrum sensing. The SDR module can be used for a wide range of applications. The use of the SDR module is motivated by its high interoperability, availability for relatively cheaper prices and being software independent. Energy detection for cognitive radios is chosen for its simplicity and popularity. However, it is chosen as a representative for a very wide range of measurements and algorithms that can be implemented in the SDR. We have used probabilities of detection and false alarm with the receiver operating characteristics (ROC) curves as performance metrics for the implemented energy…

Impedance estimation of FEA's grid in fiji islands by V-I measurement by using the synchronous reference frame-PLL

2017

In recent years there has been a significant increase in distributed renewable energy generation feeding into the grid, with resulting detriment of the stability of the network, since present networks have not been designed for this purpose. To feed-in these renewable energy sources with minimum impact, it is essential to know a few grid parameters (voltage, current, grid impedance) at the point in which power supply is convenient. For this purpose in this paper an algorithm is proposed to obtain the estimated network impedance. This algorithm operates in time domain by a synchronous reference coordinate transformation, it requires only the measurement of the phase voltage with no-load and …

Control of solid-state fault current limiter for DG-integrated distribution systems

2017

Fault current limier (FCL) is a device that limits the system current under fault conditions without disconnecting the system and affecting the power system protection components such as circuit breakers. Many types of FCLs have been proposed to limit the magnitude of the fault current. Solid-state fault current limiters (SSFCLs) can limit the peak value of the fault current by applying several methods, such as controlling the system impedance or controlling the voltage that appears across the fault. In this paper, a new control scheme for the SSFCL circuit is presented. The control method is based on controlling the duty cycle of solid state switches to control the rms value of the system …

Development of a Coupling System for Medium Voltage Power Line Communication in the CENELEC A Frequency Band

2016

In this paper the performances of a new power line communication (PLC) coupling system for medium voltage (MV) smart grids are investigated in the CENELEC A frequency band (i.e. 3 - 95 kHz). The new coupling solution is based on the use of the capacitive divider of the voltage detecting system (VDS) as PLC coupler to the MV network. According to IEC 61243-5, VDS are worldwide used to reveal the presence of the mains voltage to ensure the safety of the operators. A proper interface circuit has been invented and patented to couple the PLC signal through the VDS. In this way no dedicated MV PLC coupler is required, thus avoiding the related costs of the coupler, of its installation, and those …

Independent energetic grids for a smart island: Model and design of a microgrid for a small Italian island

2016

Unlike many Italian peninsular areas, which are increasingly turning to a diverse supply of renewable resources to generate electricity, Italian not-interconnected small islands continue to rely on oil for their electricity and other energy needs (e.g. transports). Small-scale electricity systems, that are not connected to a larger electricity grid, are usually more expensive. The present paper proposes the functional design of an innovative Smart Grid which allows changing an Italian small not-interconnected island, Pantelleria, into a smart island, towards a more sustainable energy model. In detail, a techno-economic feasibility study is performed in order to design a Smart Grid at Pantel…