Search results for "Verters"

Reliability Analysis of Three Homogeneous Fault-tolerant Inverter Topologies

2016

Abstract—In this article, non-redundant fault-tolerant inverter topologies are addressed. A novel fault-tolerant control strategy which enhances performances during post-fault operation is proposed. Benefits from the proposed strategy over conventional fault-tolerant topologies are investigated in terms of system reliability. Cost, post-fault performances, and system reliability of the proposed solution are compared with both a conventional triac-based fault-tolerant inverter and a T-type inverter. The reliability analysis of each selected configuration is carried out by means of Markov chains. The analysis is validated through a comparison of reliability and sensitivity curves. As shown by…

A lossles current sensing technique for flyback converters

2009

Power dispatching of active generators using droop control in grid connected micro-grid

2014

Masteroppgave i fornybar energi ENE 500 Universitetet i Agder 2014 Renewable energy promises a green energy future for the world. However, many technical problems still have to be solved. Almost all renewable energy sources require power electronic converters for power processing and therefore inverter control systems and power dispatching strategies are significant in renewable energy applications. The existing electricity grid architecture is based on centralized power generations while most renewable power generations are distributed and connected to lower or medium voltage networks. Some of important renewable energy resources such as solar and wind power are intermittent in nature. Thi…

Investigation about selective harmonic elimination in unbalanced multilevel inverters

2022

In this paper 5 and 7 levels cascaded H-bridges inverters are considered, feeding by unequal dc voltage sources. The effect of these unbalancing operation is examined concerning harmonic analysis and total harmonic distortion of the output voltages. The system of equations, obtained by the expansion in the Fourier series of phase output voltage, is solved by applying a method of graphic solution that allows obtaining the switching angles able to eliminate the lower order harmonics.

Benefits and Drawbacks of A High Frequency Gan Zvzcps Converter

2017

This paper presents the benefits and drawbacks of replacing the traditional Si Mosfets transistors with enhancement mode GaN transistors in a Half-Bridge Zero Voltage and Zero Current Switching Power Switching (ZVZCPS) converter. This type of converters is usually used as Electronic Power Converters (EPC) for telecommunication satellites travelling-wave tube amplifiers (TWTAs). In this study, firstly the converter is theoretically analysed, obtaining its operation, losses and efficiency equations. From these equations, optimizations maps based on the main system parameters are obtained. These optimization maps are the key to quantify the potential benefits of GaN transistors in this type of…

Design and realization of a DC/DC converter with a partially saturated inductor

2017

DC/DC converters, in some types of applications such as portable equipments, can require more space than it is actually available. The inductor is typically the most bulky element and the possibility to reduce its size can save up to 50% of the converter volume and area [1][2], thus increasing the power density. This reduction, however, comes with nonlinear effects caused by the saturation of the ferromagnetic core. An appropriate modelling of the inductor and of the converter circuit is needed for guaranteeing a good output power quality (Fig. 1). A Boost converter with an inductor in the partially saturated roll-off operating zone was designed and realized to study the behaviour of DC/DC …

Design and Performance Evaluation of a High Power-Density EMI Filter for PWM Inverter-Fed Induction-Motor Drives

2016

This paper presents the design of an electromagnetic interference (EMI) filter for a low-voltage high-current induction-motor drives supplied by dc power grids. In order to effectively design the EMI filter, a suitable common-mode/differential-mode (CM/DM) separation technique has been used. Due to the high operating currents, the software-based separation technique using time-domain measurements has been applied. The proposed technique allows the CM and DM sections of the EMI filter to be properly selected in a more economical way, i.e., without the need of a dedicated hardware or costly radio frequency (RF) instrumentation. The design has been done according to a power-density criterion. …

Development of bidirectional dc-dc converters for hybrid power sources - Final Report

2018

A Bidirectional Isolated Full-Bridge Converter was designed, prototyped and tested. The device is intended to interface a Bank of Supercapacitors with a battery-powered bus, in order to boost the capability of supplying large power peaks. The converter was based on the Isolated Dual Active Bridge configuration. When driven by an external control voltage, it is capable of generating in both directions a train of current pulses, with 2kW peak power, for any battery voltage in the range 24-32V and for any supercapacitor voltage in the range 35-70V. Worst-case battery current was 70A. Pulse duration was 100ms with 50% duty cycle and 1 ms rise time.

Grid-Following and Grid-Forming MODELS in ATP-EMTP for Power Systems Simulation

2022

The paper presents the models of grid-following and grid-forming converters in the software ATP-EMTP for power systems simulation. The models are developed using the MODELS language, they are described in details discussing all issues and aspects related to the implementation, and they are also shared as open source models. The models are validated with a simulation-based approach, comparing the results with the models developed in MATLAB/Simulink and in NEPLAN, considering both the phasor RMS and EMT time domains, and thus performing a comprehensive cross-platform and cross-domain validation. In line with the spirit of the ATP software and community, the models of grid-following and grid-f…

Damping Provision by Different Virtual Synchronous Machine Schemes

2020

The adoption of virtual synchronous machine (VSM) schemes for the control of power converters is gaining more and more attention both in academia and industry. The VSM control strategies fall into the category of grid-forming converter controls, and they are intended for a range of different applications, providing specific services and different kinds of support to the grid. The paper investigates the possibility of damping provision to the system by VSM power converters. Different schemes are considered and compared, showing the opportunity of the investigated solutions through combined modal and time domain analyses. A specific modification of the power synchronization loop is recognized…