A literature survey on AC-DC Converter using three phase single stage PFC & PWM Technique

Today to achieve ac-dc power conversions with high input power factor and low harmonic distortions, Power factor correction (PFC) converters are widely used. This paper lays out the research and development done in the field of PFC’s. Converter topologies, control strategies, power quality etc has been discussed here. Higher power ratings, faster switching speed and lower cost are the areas of concern for digital controllers and converters and thus PFC has gained attention

High step up DC-DC converter topology for PV systems and electric vehicles

This thesis presents new high step-up DC-DC converters for photovoltaic and electric vehicle applications. An asymmetric flyback-forward DC-DC converter is proposed for the PV system controlled by the MPPT algorithm. The second converter is a modular switched-capacitor DC-DC converter, it has the capability to operate with transistor and capacitor open-circuit faults in every module. The results from simulations and tests of the asymmetric DC-DC converters have suggested that the proposed converter has a 5% to 10% voltage gain ratio increased to the symmetric structures among 100W – 300W power (such as [3]) range while maintaining efficiency of 89%-93% when input voltage is in the range of 25 – 30 V. they also indicated that the softswitching technique has been achieved, which significantly reduce the power loss by 1.7%, which exceeds the same topology of the proposed converter without the softswitching technique. Moreover, the converters can maintain rated outputs under main transistor open circuit fault situation or capacitor open circuit faults. The simulation and test results of the proposed modularized switched-capacitor DC-DC converters indicate that the proposed converter has the potential of extension, it can be embedded with infinite module in simulation results, however, during experiment. The sign open circuit fault to the transistors and capacitors would have low impact to the proposed converters, only the current ripple on the input source would increase around 25% for 4-module switched-capacitor DC-DC converters. The developed converters can be applied to many applications where DC-DC voltage conversion is alighted. In addition to PVs and EVs. Since they can ride through some electrical faults in the devices, the developed converter will have economic implications to improve the system efficiency and reliability

Resonant Behaviour of Pulse Generators for the Efficient Drive of Optical Radiation Sources Based on Dielectric Barrier Discharges

Dielectric barrier discharge (DBD) excimer lamps emit vacuum-UV optical radiation. This work presents novel methods for efficiently operating DBDs with short, high-voltage pulses. Transformer-less systems utilising SiC power semiconductor switches are presented. Pulse frequencies of up to 3.1 MHz and peak inverter efficiencies of 92 % were achieved. The work encloses both mathematical backgrounds of pulsed resonant circuits and practical implementation of low-inductive power stages

Design and Control of Power Converters 2020

In this book, nine papers focusing on different fields of power electronics are gathered, all of which are in line with the present trends in research and industry. Given the generality of the Special Issue, the covered topics range from electrothermal models and losses models in semiconductors and magnetics to converters used in high-power applications. In this last case, the papers address specific problems such as the distortion due to zero-current detection or fault investigation using the fast Fourier transform, all being focused on analyzing the topologies of high-power high-density applications, such as the dual active bridge or the H-bridge multilevel inverter. All the papers provide enough insight in the analyzed issues to be used as the starting point of any research. Experimental or simulation results are presented to validate and help with the understanding of the proposed ideas. To summarize, this book will help the reader to solve specific problems in industrial equipment or to increase their knowledge in specific fields

Low Power AC-DC and DC-DC Multilevel Converters

AC-DC power electronic converters are widely used for electrical power conversion in many industrial applications such as for telecom equipment, information technology equipment, electric vehicles, space power systems and power systems based on renewable energy resources. Conventional AC-DC converters generally have two conversion stages – an AC-DC front-end stage that operates with some sort of power factor correction to ensure good power quality at the input, and a DC-DC conversion stage that takes the DC output of the front-end converter and converts it to the desired output DC voltage. Due to the cost of having two separate and independent converters, there has been considerable research on so-called single-stage converters – converters that can simultaneously perform AC-DC and DC-DC conversion with only a single converter stage. In spite of the research that has been done on AC-DC single-stage, there is still a need for further research to improve their performance. The main focus of this thesis is on development of new and improved AC-DC single-stage converters that are based on multilevel circuit structures (topologies) and principles instead of conventional two-level ones. The development of a new DC-DC multilevel converter is a secondary focus of this thesis. In this thesis, a literature survey of state of the art AC-DC and DC-DC converters is performed and the drawbacks of previous proposed converters are reviewed. A variety of new power electronic converters including new single-phase and three-phase converters and a new DC-DC converter are then proposed. The steady-state characteristics of each new converter is determined by mathematical analysis, and, once determined, these characteristics are used to develop a procedure for the design of key converter components. The feasibility of all new converters is confirmed by experimental results obtained from proof-of-concept prototype converters. Finally, the contents of the thesis are summarized and conclusions about the effectiveness of using multilevel converter principles to improve the performance of AC-DC and DC-DC converters are made

DC-DC and AC-DC Converters Based on Three-Phase DC-DC Topologies

Power electronics is the field of electrical engineering that uses power semiconductor devices along with passive elements such as inductors, capacitor and transistors to convert electrical power that can be generated by a source to a form that is suitable for user loads. The main focus of this thesis is on the development of new DC-DC and AC-DC topologies that are based on three-phase DC-DC converters. Three-phase DC-DC converters take an input DC voltage, convert it into a high-frequency AC voltage that is then stepped up or down, then rectify and filter this voltage to produce an output DC voltage. They are implemented with a high-frequency three-phase transformer in their topology rather than a single-phase transformer. These converters are very attractive over other topologies that have a single-phase transformer in their topologies for several reasons. First, just one three-phase DC-DC converter can be used instead of using three DC-DC converters in parallel for particular applications; this advantage is especially attractive for higher power applications. In addition, by using three-phase DC-DC converters, the ripple of the source current is significantly reduced and that means less filtering is needed. Moreover, the components of the converter will have less current stress because current is split among three-phases. In this thesis, new DC-DC and AC-DC converters that are based on three-phase DC-DC topology are proposed. The proposed converters use fewer active switches than other previously proposed converters of similar type, thus resulting in lower cost and simpler operation. For each of the proposed converters, its steady-state characteristics are determined by mathematical analysis and procedure for the design of key converter components is developed. The feasibility of each proposed converter has been confirmed with results that have been obtained from experimental prototypes. For one of the proposed converters, a comparison between the operation of one of the proposed converters operating with traditional silicon devices (Si) and that with the converter operating with new silicon-carbide devices (SiC) was made to examine its performance with both types of devices

Resonant Behaviour of Pulse Generators for the Efficient Drive of Optical Radiation Sources Based on Dielectric Barrier Discharges

Excimer-Lampen basierend auf Dielektrisch Behinderten Entladungen (DBD) sind effiziente Quellen ultravioletter Strahlung. Diese Arbeit verbindet theoretische Betrachtungen mit der praktischen Verifikation neu entwickelter Topologien und Betriebsmodi, um DBEs effizient mit kurzen Hochspannungspulsen zu betreiben. Durch transformatorlose Topologien und Nutzung von SiC Leistungshalbleitern konnten Effizienzen von bis zu 92 % und Pulsfrequenzen von bis zu 3.1 MHz erreicht werden

Applications Technology Satellite ATS-6 experiment checkout and continuing spacecraft evaluation report

The activities of the ATS-6 spacecraft are reviewed. The following subsystems and experiments are summarized: (1) radio beacon experiments; (2) spacecraft attitude precision pointing and slewing adaptive control experiment; (3) satellite instruction television experiment; (4) thermal control subsystem; (5) spacecraft propulsion subsystem; (6) telemetry and control subsystem; (7) millimeter wave experiment; and (8) communications subsystem. The results of performance evaluation of its subsystems and experiments are presented

Research and technology, fiscal year 1986, Marshall Space Flight Center

The Marshall Space Flight Center is continuing its vigorous efforts in space-related research and technology. Extensive activities in advanced studies have led to the approval of the Orbital Maneuvering Vehicle as a new start. Significant progress was made in definition studies of liquid rocket engine systems for future space transportation needs and the conceptualization of advanced laucnch vehicles. The space systems definition studies have brought the Advanced X-ray Astrophysics Facility and Gravity Probe-B to a high degree of maturity. Both are ready for project implementation. Also discussed include significant advances in low gravity sciences, solar terrestrial physics, high energy astrophysics, atmospheric sciences, propulsion systems, and on the critical element of the Space Shuttle Main Engine in particular. The goals of improving the productivity of high-cost repetitive operations on reusable transportation systems, and extending the useful life of such systems are examined. The research and technology highlighted provides a foundation for progress on the Hubble Space Telescope, the Space Station, all elements of the Space Transportation System, and the many other projects assigned to this Center