Search results for " Inverter"

INVERTER-BASED DISTRIBUTED GENERATORS, MODELING AND CONTROL

In the last few years, electrical power generation is moving from a centralized generation towards distributed generation including on-site Renewable Energy Sources (RESs). In order to overcome RES related issues, as intermittent and fluctuating power, storage elements are included in the on-site generation system. The interaction between distributed generator (DG) units including RES, storage and front-end power converters should be carefully modeled in order to analyze the power system stability. An accurate modeling of DGs is required. In this thesis, a new modeling approach has been proposed for the inverter-based DGs based on the concept of electrostatic synchronous machines. Detailed …

An experimental analysis of power quality in presence of single phase grid connected photovoltaic systems

2004

In this paper, an experimental power quality analysis in presence of single phase grid connected PV systems is performed in a PV system installed at the Department of Electric Engineering of the University of Palermo through a measurement system set up by the Authors. In particular the analysis has been carried out focusing the attention on voltage and current distortion, as the solar radiation varies. The corresponding Total Harmonic Distortions in voltage and current terms are reported and compared with the standards limits. The presence of interharmonic components is also discussed.

Adaptive Feed-Forward Neural Network for Wind Power Delivery

2022

This paper describes a grid connected wind energy conversion system. The interconnecting filter is a simple inductor with a series resistor to minimize three-phase current Total Harmonic Distortion (THD). Using the Recursive Least Squares (RLS) Estimator, an online grid impedance technique is proposed in the stationary reference frame using the Recursive Least Squares (RLS) Estimator. An Adaptive Feedforward Neural (AFN) Controller has also been developed using the inverse of the system to improve the performance of the current Proportional-Integral controller under dynamical conditions and provide better DC link voltage stability. The neural network weights are computed in real-time using …

A Configuration of 3-phase Traction Inverter Employing {SiC} Devices

2022

In the scenario of a more and more sustainable society, an increasing electrification in different fields, such as mobility and industrial applications, is foreseen in the next decades. As far as power electronics is concerned, a challenging perspective is represented by achieving higher and higher switching frequencies while maintaining high voltage and low power losses. To do that, emerging semiconductor technologies are supposed to be increasingly employed, as well as innovative topologies of connections among switching devices. Among them, the cascode configuration can notably contribute to achieve high levels of dV/dt without losing efficiency. In this paper, a 3-phase Pulse Width Modu…

A reexamination of voltage distortion for classical carrier-based vs B-Spline modulation of three-phase Voltage Sources Inverters

2015

Voltage waveform improvement has been the object of several investigations for many years and a manifold of different solutions have been proposed to reduce the harmonic content in Voltage Source Inverters (VSI) power application. In many cases this improvements have been obtained by modifying the reference voltage modulating signal. The recent introduction of cardinal B-spline functions, used as carrier signals, has given rise to a new modulation technique whose main characteristic is a lower value of the Total Harmonic Distortion (THD). After the discussion on the B-Spline modulation principle and on its computational effort, a performance comparisons is carried out by means of Total Harm…

Switching Frequency Effects on the Efficiency and Harmonic Distortion in a Three-Phase Five-Level CHBMI Prototype with Multicarrier PWM Schemes: Expe…

2022

The current climatic scenario requires the use of innovative solutions to increase the production of electricity from renewable energy sources. Multilevel Power Inverters are a promising solution to improve the penetration of renewable energy sources into the electrical grid. Moreover, the performance of MPIs is a function of the modulation strategy employed and of its features (modulation index and switching frequency). This paper presents an extended and experimental analysis of three-phase five-level Cascaded H-Bridges Multilevel Inverter performance in terms of efficiency and harmonic content considering several MC PWM modulation strategies. In detail, the CHBMI performance is analyzed …

Comprehensive Modeling and Experimental Testing of Fault Detection and Management of a Nonredundant Fault-Tolerant VSI

2015

This paper presents an investigation and a comprehensive analysis on fault operations in a conventional three-phase voltage source inverter. After an introductory section dealing with power converter reliability and fault analysis issues in power electronics, a generalized switching function accounting for both healthy and faulty conditions and an easy and feasible method to embed fault diagnosis and reconfiguration within the control algorithm are introduced. The proposed system has simple and compact implementation. Experimental results operating both at open- and closed-loop current control, obtained using a test bench realized using a dSPACE system and the fault-tolerant inverter protot…

Mathematical formulation of pulse amplitude modulation selective harmonic elimination in multilevel three phase inverters

2022

In this paper multilevel cascaded H-bridges (CHB) three phase inverters with 2n dc sources, n=1,2,3,... are considered and a mathematical formulation providing both 2n switching angles and dc voltage source to eliminate n+1 harmonics and their respective multiple from their output voltage waveform, is proposed. The computed angles don't depend on modulation index and the source voltages linearly vary with it. The proposed procedure finds the solution through an analytical formula that avoids to solve transcendental systems and presents very low computational cost. A lot of low order harmonics are eliminated, returning a very low total harmonic distortion (THD). Particularly for 9-level conf…

Experimental Comparative Analysis of Efficiency and THD for a Three-phase Five-level Cascaded H-Bridge Inverter Controlled by Several MC-PWM Schemes

2021

Cascaded H-Bridges Multilevel Inverters are an innovative and promising solution in different application fields. This topology allows obtaining an improvement in the performance (e.g. reduced harmonic content, the low voltage stress on power components, and high efficiency) in respect to the traditional two-level inverters. In this context, the Multicarrier-PWM strategies play an important role thanks to their features. This paper presents an experimental investigation on the performance of a three-phase five-level Cascaded H-Bridge inverter by using different PWM modulation strategies. In particular, the paper is focused on the experimental validation of the main features of Multicarrier …

Mixed Harmonic Elimination Control for a Single-Phase 9 Level Grid-Connected Inverter

2018

The power quality requirements are increasingly stringent, due to the continuous growth of devices connected to the grid that introduce harmonics. These devices include DC to AC energy conversion systems, i.e. grid connected inverters. The design, control and operation of these systems must take into account the rules of interconnection to the electricity grid. To improve the quality of the output waveform of the grid-connected inverter, Multilevel Converters (MC) with selective harmonic elimination modulation technique can be used. This paper presents a single-phase nine level grid-connected inverter with DC/DC input stages. The obtained switching angles for THD minimization are independen…