Multilevel Converters: An Enabling Technology for High-Power Applications

| Multilevel converters are considered today as the state-of-the-art power-conversion systems for high-power and power-quality demanding applications. This paper presents a tutorial on this technology, covering the operating principle and the different power circuit topologies, modulation methods, technical issues and industry applications. Special attention is given to established technology already found in industry with more in-depth and self-contained information, while recent advances and state-of-the-art contributions are addressed with useful references. This paper serves as an introduction to the subject for the not-familiarized reader, as well as an update or reference for academics and practicing engineers working in the field of industrial and power electronics.Ministerio de Ciencia y Tecnología DPI2001-3089Ministerio de Eduación y Ciencia d TEC2006-0386

Hybrid switched-capacitor/switched-quasi-Z-source bidirectional DC-DC converter with wide-voltage-gain range for hybrid energy sources EVs

In this paper, a hybrid switched-capacitor/ switched-quasi-Z-source bidirectional dc-dc converter is proposed for electric vehicles (EVs) with hybrid energy sources, which has a wide voltage gain range in the bidirectional energy flows. Compared with the traditional quasi-Z-source bidirectional dc-dc converter, the proposed converter only changes the position of the main power switch, and employs a switched-capacitor cell at the output of the high voltage side. Therefore, the advantages of the wide voltage gain range and the lower voltage stresses across the power switches can be achieved. The operating principle, the voltage and current stresses across the power switches and the comparisons with other converters are analyzed in detail. Furthermore, the parameter design of the main components, the dynamic modelling analysis and the voltage control scheme are also presented. Finally, the experimental results obtained from a 400W prototype validate the characteristics and the theoretical analysis of the proposed converter

Issues concerning centralized versus decentralized power deployment

The results of a study of proposed lunar base architectures to identify issues concerning centralized and decentralized power system deployment options are presented. The power system consists of the energy producing system (power plant), the power conditioning components used to convert the generated power into the form desired for transmission, the transmission lines that conduct this power from the power sources to the loads, and the primary power conditioning hardware located at the user end. Three power system architectures, centralized, hybrid, and decentralized, were evaluated during the course of this study. Candidate power sources were characterized with respect to mass and radiator area. Two electrical models were created for each architecture to identify the preferred method of power transmission, dc or ac. Each model allowed the transmission voltage level to be varied at assess the impact on power system mass. The ac power system models also permitted the transmission line configurations and placements to determine the best conductor construction and installation location. Key parameters used to evaluate each configuration were power source and power conditioning component efficiencies, masses, and radiator areas; transmission line masses and operating temperatures; and total system mass

A study of high-frequency-fed AC-DC converter with different DC-DC topologies

In this paper, the operation of high-frequency-fed AC-DC converters with different types of DC-DC topologies is presented. Based on the commonly used DC-DC converter topologies, the possibilities of new converter structure are investigated. Using buck and ZETA topologies as examples, the output voltage gain, output load range and switch stress of the converters are analytically studied. Both converter implementation examples will be given and experimentally demonstrated. © IEEE.published_or_final_versio

An Efficiency-Focused Design of Direct-DC Loads in Buildings

Despite the recent interest in direct current (DC) power distribution in buildings, the market for DC-ready loads remains small. The existing DC loads in various products or research test beds are not always designed to efficiently leverage the benefits of DC. This work addresses a pressing need for a study into the development of efficient DC loads. In particular, it focuses on documenting and demonstrating how to best leverage a DC input to eliminate or improve conversion stages in a load’s power converter. This work identifies how typical building loads can benefit from DC input, including bath fans, refrigerators, task lights, and zone lighting. It then details the development of several prototypes that demonstrate efficiency savings with DC. The most efficient direct-DC loads are explicitly designed for DC from the ground up, rather than from an AC modification

An algorithm for automatically calculating component current ratings in switched capacitor DC-DC converters

OAPA Switched Capacitor (SC) DC-DC converters, which have traditionally been used for on-chip power supplies, are now being considered for medium to high-power applications. This paper presents a method for automatically synthesising SC converters as well as deriving the expressions for their chargemultipliers. Charge multipliers can be used to calculate important design characteristics such as converter output voltage regulation, efficiency and component current ratings, which can then be used to appraise different topologies. However, whilst a full appraisal of converters also requires component voltage ratings, this work is the first step in developing an automatic software tool that will employ a search-based algorithm to generate optimum SC topologies for a given application. The method is based on the proposition that all SC converters can be synthesised from a so-called "basic cell". The automatic derivation and solution of the charge transfer equations for a traditional Fibonacci SC converter is presented as an example of the proposed method, which is validated against existing analytic equations as well as a detailed Spice simulation. The automatic calculation of the charge-multipliers for two other well-known SC converters is also demonstrated, including a new, arbitrarily generated circuit, which again are validated against detailed Spice simulations

Single Switch DC-DC Converter for Battery Feed Electrical Vehicle

A new single-switch transformer less lift DC-DC converter has been suggested that energy component cars could benefit from a new single-switch transformer reduced lift DC-DC converter. The newly developed topology makes use of a different capacitor multiplier and an integrated LC2D yield organise in order to improve the voltage addition of the converter and reduce the voltage load that is placed on the force switch. In addition, the suggested converter features a broad voltage gain range, which allows it to accommodate a broad variety of voltage swings produced by the energy component. The operating standards of the suggested converter as well as its consistent state examinations are presented below. Recreation was utilised in the production of a scaled-down, exploratory model that had 800 V and 1 kW. The outcomes of the re-enactment demonstrate that the framework is sufficient