Computer-Aided Modeling and Analysis of Power Processing Systems (CAMAPPS), phase 1

The large-signal behaviors of a regulator depend largely on the type of power circuit topology and control. Thus, for maximum flexibility, it is best to develop models for each functional block a independent modules. A regulator can then be configured by collecting appropriate pre-defined modules for each functional block. In order to complete the component model generation for a comprehensive spacecraft power system, the following modules were developed: solar array switching unit and control; shunt regulators; and battery discharger. The capability of each module is demonstrated using a simplified Direct Energy Transfer (DET) system. Large-signal behaviors of solar array power systems were analyzed. Stability of the solar array system operating points with a nonlinear load is analyzed. The state-plane analysis illustrates trajectories of the system operating point under various conditions. Stability and transient responses of the system operating near the solar array's maximum power point are also analyzed. The solar array system mode of operation is described using the DET spacecraft power system. The DET system is simulated for various operating conditions. Transfer of the software program CAMAPPS (Computer Aided Modeling and Analysis of Power Processing Systems) to NASA/GSFC (Goddard Space Flight Center) was accomplished

Design and implementation of 30kW 200/900V LCL modular multilevel based DC/DC converter for high power applications

This paper presents the design, development and testing of a 30kW, 200V/900V modular multilevel converter (MMC) based DC/DC converter prototype. An internal LCL circuit is used to provide voltage stepping and fault tolerance property. The converter comprises two five level MMC based on insulated gate bipolar transistors (IGBTs) and metal oxide semiconductor field effect transistor (MOSFET). Due to low number of levels, selective harmonic elimination modulation (SHE) is used, which determines the switching angles in such a way that third harmonic is minimized whereas the fundamental component is a linear function of the modulation index. In addition, instead of using an expensive control board, three commercial control boards are embedded. This is required to implement the sophisticated DC/DC converter control algorithm. Simulation and experimental results are presented to demonstrate the converter performance in step up and down modes

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

One-Quadrant Switched-Mode Power Converters

This article presents the main topics related to one-quadrant power converters. The basic topologies are analysed and a simple methodology to obtain the steady-state output-input voltage ratio is set out. A short discussion of different methods to control one-quadrant power converters is presented. Some of the reported derived topologies of one-quadrant power converters are also considered. Some topics related to one-quadrant power converters such as synchronous rectification, hard and soft commutation, and interleaved converters are discussed. Finally, a brief introduction to resonant converters is given.Comment: 25 pages, contribution to the 2014 CAS - CERN Accelerator School: Power Converters, Baden, Switzerland, 7-14 May 201

Passivity-based harmonic control through series/parallel damping of an H-bridge rectifier

Nowadays the H-bridge is one of the preferred solutions to connect DC loads or distributed sources to the single-phase grid. The control aims are: sinusoidal grid current with unity power factor and optimal DC voltage regulation capability. These objectives should be satisfied, regardless the conditions of the grid, the DC load/source and the converter nonlinearities. In this paper a passivity-based approach is thoroughly investigated proposing a damping-based solution for the error dynamics. Practical experiments with a real converter validate the analysis.

Robust H8 design for resonant control in a CVCF inverter application over load uncertainties

CVCF (constant voltage, constant frequency) inverters are electronic devices used to supply AC loads from DC storage elements such as batteries or photovoltaic cells. These devices are used to feed different kinds of loads; this uncertainty requires that the controller fulfills robust stability conditions while keeping required performance. To address this, a robust H8 design is proposed based on resonant control to track a pure sinusoidal voltage signal and to reject the most common harmonic signals in a wide range of loads. The design is based on the definition of performance bounds in error signal and weighting functions for covering most uncertainty ranges in loads. Experimentally, the H8 controller achieves high-quality output voltage signal with a total harmonic distortion less than 2%Peer ReviewedPostprint (published version

High-Performance Isolated Bidirectional DC-DC Converter

Conversores DC-DC bidireccionais têm vindo a ganhar atenção na área da eletrónica de potência devido ao aumento da necessidade de um fluxo de potência controlado entre dois barramentos DC. Aplicações típicas podem ser facilmente listadas, indo desde unidades de produção de energia renovável até veículos elétricos e híbridos. Estes conversores podem apresentar funcionalidades como elevada densidade energética e performance, assim como isolamento galvânico entre cada porto. Desta forma, a AddVolt requisitou que tal conversor fosse incluído na sua solução de travagem regenerativa. Com esta dissertação, um conversor DC-DC bidireccional e isolado é proposto, sendo que todos os aspetos desde revisão bibliográfica, modelação, design, simulação, implementação, teste e validação são abrangidos. Um conversor Dual-Active Bridge (DAB) de média potência e alta frequência é a topologia escolhida. Após validação de quer a topologia como a malha de controlo desenhada num ambiente computacional, um protótipo experimental é assemblado e testado com sucesso. O isolamento galvânico é garantido e atingido através de um transformador de alta frequência desenhado e enrolado pelo autor.Bidirectional DC-DC converters have been gaining attention in the field of power electronics due to the increasing need of a controlled power flow between two DC buses. Typical applications can be easily listed, ranging from renewable energy production units to electric and hybrid vehicles. Such converters can feature characteristics as high power density and performance as well as isolation between each port. As a result, AddVolt has commissioned that such a converter should be included in its regenerative breaking solution. Within this dissertation, a bidirectional isolated DC-DC converter is proposed, and all aspects from literature review, modelling, design, simulation, implementation, testing and validation are deeply covered. A medium-power high frequency Dual-Active Bridge (DAB) converter is the chosen topology. After validation of both the topology and control structure in a computational environment, an experimental prototype is assembled and successfully tested. Galvanic isolation is granted and achieved by a self-designed and in-house wound high frequency transformer