Projeto e análise de rendimento de uma UPS monofásica de três braços e construção de um calorímetro fechado de dupla caixa-Autor:Renato Atila Silva Santana---Universidade Federal de Minas Gerais Escola de Engenharia Programa de Pós-Graduação em Engenharia Elétrica

 Abstract: An UPS is an equipment that provides continuous power supply, with high levels of quality and reliability. This equipment is usually employed for supplying mission-critical systems, in which disturbances or power interruptions can cause financial losses or damages (e.g., hospitals, bank offices, datacenters, etc.). In the literature, several topologies have been proposed as an alternative to the classical configuration with low-frequency transformers, as a solution for enhancing efficiency and power density and decreasing overall costs. Among these alternatives, transformerless solutions (i.e., without transformers) become promising, as they do not require low-frequency transformers which comprise an expressive part of overall weight and volume of a conventional UPS. In this context, a three-arm UPS is often reported as a suitable transformerless topology for low- and medium-power single-phase UPS, with high efficiency and power density. This thesis aimed to assess the performance of the single-phase three-arm UPS, concerning efficiency and power density. An alternative connection for battery set was also evaluated. Furthermore, a prototype of a direct double-jacketed calorimeter was built in order to measure the losses of power converters. The adopted methodology was based on the comparison of several three-arm UPS designs with devices made by different materials (silicon, silicon carbide and gallium nitride) and of various technologies (IGBTs, MOSFETs and cascode configuration with silicon MOSFET and GaN HFET) and packages (TO-247-3, TO-247-4, SMT top and HSOF-8). The UPS was also simulated in MATLAB/Simulink, in order to validate the modulation strategies and the techniques adopted for controlling, synchronizing and commutating between the normal state and the stored energy mode, as well as the alternative connection of the battery set. These simulations demonstrated the operation in asynchronous and synchronous modes, i.e., with an output frequency that can be decoupled or not to the means frequency. All details related to construction, dimensioning and calibration of the double-jacketed calorimeter were also presented. Preliminary experimental results were also discussed in this thesis.

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https://repositorio.ufmg.br/bitstream/1843/RAOA-BC2HSD/1/main_dissertacao_renato_atila_silva_santana.pdf

A Practical Guide for Advanced Methods in Solar Photovoltaic Systems editado por Adel Mellit, Mohamed Benghanem- GOOGLE BOOK DEMO

 

Analysis and Design of Power Converter Topologies for Application in Future ... Por Amit Kumar Singh-GOOGLE BOOK

 

Model Predictive Control for Paralleled Uninterruptible Power Supplies with an Additional Inverter Leg for Load-Side Neutral Connection Tiago Oliveira , Luís Caseiro , André Mendes , Sérgio Cruz and Marina Perdigão Department of Electrical and Computer Engineering, University of Coimbra-

Abstract Uninterruptible Power Supplies (UPS) have been demonstrated to be the key technology in feeding either single- and three-phase loads in a wide range of critical applications, such as high-tier datacenters and medical facilities. To increase the overall system power capacity and resilience, UPS systems are usually connected in parallel. When UPS systems are parallel connected, a circulating current can rise, inhibiting correct system operation. Moreover, having a controlled load power distribution is another fundamental requirement in paralleled UPS systems. However, strategies to ensure these two topics have not been explored to date for UPS systems with a load-side neutral connection. This paper proposes an innovative Finite Control Set Model Predictive Control (FCS-MPC) strategy that ensures circulating current elimination and controlled load power distribution for paralleled UPS systems that use an additional inverter leg for load neutral point connection. Additionally, a system topology based on two parallel-connected UPS systems that can simultaneously supply single- and three-phase critical loads is proposed. Experimental results show the effectiveness and robustness of the proposed control techniques even when different types of loads are connected to the UPS systems. 

VIEW FULL TEXT WEB: https://www.mdpi.com/1996-1073/14/8/2270

LINK : https://www.mdpi.com/1996-1073/14/8/2270/pdf

High-Power-Density GaN-Based Single-Phase Online Uninterruptible Power Supply Danish Shahzad, Nauman Zaffar*, Khurram K. Afridi Department of Electrical and Computer Engineering Cornell University Ithaca, New York, USA ds2358@cornell.edu, afridi@cornell.edu *Lahore University of Management Sciences Lahore, Pakistan

Abstract— This paper introduces a new topology suitable for a high-power-density single-phase online uninterruptible power supply (UPS) with a common neutral between its input and output ac ports while avoiding a split dc bus. The proposed topology enables high power density by utilizing half-bridge switch structures compatible with MHz-frequency operation. High efficiency is maintained in this converter by achieving soft-switching in rectifier stage with a boundary conduction mode control strategy. A comprehensive design methodology is developed to optimize the design of this converter. A 1-kVA prototype online UPS based on the proposed topology that utilizes GaN transistors and operates at switching frequencies up to 2 MHz is built and tested. The prototyped UPS achieves a power density of 26.4 W/in3.

 LINK:https://www.semanticscholar.org/paper/High-Power-Density-GaN-Based-Single-Phase-Online-Shahzad-Zaffar/4423c3c34e093b91970248d1de813d8db2016d91