A Novel Control Mechanism For Hybrid 5 Level Dc Dc Converter For Higher Switching Frequency And Lower Voltage Ripple
DOWNLOAD
Download A Novel Control Mechanism For Hybrid 5 Level Dc Dc Converter For Higher Switching Frequency And Lower Voltage Ripple PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get A Novel Control Mechanism For Hybrid 5 Level Dc Dc Converter For Higher Switching Frequency And Lower Voltage Ripple book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages. If the content not found or just blank you must refresh this page
A Novel Control Mechanism For Hybrid 5 Level Dc Dc Converter For Higher Switching Frequency And Lower Voltage Ripple
DOWNLOAD
Author : Mohamed Samir Mazloum
language : en
Publisher:
Release Date : 2017
A Novel Control Mechanism For Hybrid 5 Level Dc Dc Converter For Higher Switching Frequency And Lower Voltage Ripple written by Mohamed Samir Mazloum and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2017 with DC-to-DC converters categories.
Abstract: The introduction and development of hybrid DC-DC converters present a valuable opportunity in on-chip power management, as they combine the advantages of buck and switched-capacitor converters while alleviating shortcomings such as conversion efficiency and sizing requirements. In this paper, a new control methodology is presented for the recently developed 5-level hybrid DC-DC converter, which utilizes the Virtex 5 LX50T FPGA to drive the converter. This control method allows for a higher switching frequency of 1MHz and an improved conversion efficiency while also allowing for dynamic voltage control based on the desired output voltage. Simulations as well as a test circuit are used to illustrate the proper control functionality, with tabulated results that showcase the efficiency advantage over prior control methods as well as the buck and 3-level hybrid converters.
Integrated Switching Dc Dc Converters With Hybrid Control Schemes
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2009
Integrated Switching Dc Dc Converters With Hybrid Control Schemes written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2009 with categories.
In the modern world of technology, highly sophisticated electronic systems pave the way for future's information technology breakthroughs. However, rapid growth on complexity and functions in such systems has also been a harbinger for the power increase. Power management techniques have thus been introduced to mitigate this urgent power crisis. Switching power converters are considered to be the best candidate due to their high efficiency and voltage conversion flexibility. Moreover, switching power converter systems are highly nonlinear, discontinuous in time, and variable. This makes it viable over a wide operating range, under various load and line disturbances. However, only one control scheme cannot optimize the whole system in different scenarios. Hybrid control schemes are thus employed in the power converters to operate jointly and seamlessly for performance optimization during start-up, steady state and dynamic voltage/load transient state. In this dissertation, three switching power converter topologies, along with different hybrid control schemes are studied. First, an integrated switching buck converter with a dual-mode control scheme is proposed. A pulse-train (PT) control, employing a combination of four pulse control patterns, is proposed to achieve optimal regulation performance. Meanwhile, a high-frequency pulse-width modulation (PWM) control is adopted to ensure low output ripples and avoid digital limit cycling. Second, an integrated buck-boost converter with a tri-mode digital control is presented. It employs adaptive step-up/down voltage conversion to enable a wide range of output voltage. This is beneficial to ever-increasing dynamic voltage scaling (DVS) enabled, modern power-efficient VLSI systems. DVS adaptively adjusts the supply voltage and operation frequency according to instantaneous power and performance demand, such that a system is constantly operated at the lowest possible power level without compromising its performance. Third, a digital integrated single-inductor multiple-output (SIMO) converter, tailored for DVS-enabled multicore systems is addressed. With a multi-mode control algorithm, DVS tracking speed and line/load regulation are significantly improved, while the converter still retains low cross regulation. All three integrated CMOS DC-DC converters have been designed and fabricated successfully, demonstrating the techniques proposed in this research. The measurements results illustrate superior line and load regulation performances and dynamic response in all these designs.
Schiff Base Metal Complexes
DOWNLOAD
Author : Pranjit Barman
language : en
Publisher: John Wiley & Sons
Release Date : 2023-05-11
Schiff Base Metal Complexes written by Pranjit Barman and has been published by John Wiley & Sons this book supported file pdf, txt, epub, kindle and other format this book has been release on 2023-05-11 with Science categories.
Schiff Base Metal Complexes Schiff bases are compounds created from a condensed amino compounds, which frequently form complexes with metal ions. They have diverse applications in biology, catalysis, material science and industry. Understanding these compounds, their properties, and the available methods for synthesizing them is a key to unlocking industrial innovation. Schiff Base Metal Complexes provides a comprehensive overview of these compounds. It introduces the compounds and their properties before discussing their various synthesizing methods. A survey of existing and potential applications gives a complete picture and makes this a crucial guide for researchers and industry professionals looking to work with Schiff base complexes. Schiff Base Metal Complexes readers will also find: A systematic and organized structure designed to make information instantly accessible Detailed coverage of thermal synthesis, photochemical synthesis, and more Challenges with different methods described in order to help readers make the correct choice for their own work Schiff Base Metal Complexes is a useful reference for organic chemists, materials scientists, and researchers or industry professionals working with organometallics.
High Performance Integrated Controller With Variable Frequency Control For Switching Dc Dc Converters
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2004
High Performance Integrated Controller With Variable Frequency Control For Switching Dc Dc Converters written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2004 with categories.
Development of digital core chips poses serious challenges to the power supply design. High performance switching DC-DC converter must meet requirements of high current, low voltage tolerance, fast transient response, high power efficiency, small profile and low cost. The conventional PWM control with constant switching frequency has limitation to improve both transient response and power efficiency because there is a conflicting requirement on switching frequency. The control scheme with variable frequency has promising features to achieve better overall performance, but the issues in the reported design approaches limit their usefulness in the practical applications. This dissertation reviews and summarizes the issues and the design considerations in the high current switching DC-DC converters. To improve the system performance, novel control architecture with variable switching frequency and novel implementation of the integrated controller are proposed in this dissertation. The proposed control architecture is modeled and analyzed. Fully differential circuits are designed to implement the control core functions. The design methodology and the design considerations are discussed. The control concept and the proposed circuits are verified by the prototype controller chip.
Analysis Modeling And Control Of Highly Efficient Hybrid Dc Dc Conversion Systems
DOWNLOAD
Author : Ruichen Zhao
language : en
Publisher:
Release Date : 2012
Analysis Modeling And Control Of Highly Efficient Hybrid Dc Dc Conversion Systems written by Ruichen Zhao and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012 with categories.
This dissertation studies hybrid dc-dc power conversion systems based on multiple-input converters (MICs), or more generally, multiport converters. MICs allow for the integration of multiple distributed generation sources and loads. Thanks to the modular design, an MIC yields a scalable system with independent control in all sources. Additional characteristics of MICs include the improved reliability and reduced cost. This dissertation mainly studies three issues of MICs: efficiency improvement, modeling, and control. First, this work develops a cost-effective design of a highly-efficient non-isolated MIC without additional components. Time-multiplexing (TM) MICs, which are driven by a time-multiplexing switching control scheme, contain forward-conducting-bidirectional-blocking (FCBB) switches. TM-MICs are considered to be subject to low efficiency because of high power loss introduced by FCBB switches. In order to reduce the power loss in FCBB switches, this work adopts a modified realization of the FCBB switch and proposes a novel switching control strategy. The design and experimental verifications are motivated through a multiple-input (MI) SEPIC converter. Through the design modifications, the switching transients are improved (comparing to the switching transients in a conventional MI-SEPIC) and the power loss is significantly reduced. Moreover, this design maintains a low parts-count because of the absence of additional components. Experimental results show that for output power ranging from 1 W to 220 W, the modified MIC presents high efficiency (96 % optimally). The design can be readily extended to a general n-input SEPIC. The same modifications can be applied to an MI-Ćuk converter. Second, this dissertation examines the modeling of TM-MICs. In the dynamic equations of a TM-MIC, a state variable from one input leg is possible to be affected by state variables and switching functions associated with other input legs. In this way, inputs are coupled both topologically and in terms of control actions through switching functions. Coupling among the state variable and the time-multiplexing switching functions complicate TM-MICs' behavior. Consequently, substantial modeling errors may occur when a classical averaging approach is used to model an MIC even with moderately high switching frequencies or small ripples. The errors may increase with incremental number of input legs. In addition to demonstrating the special features on MIC modeling, this dissertation uses the generalized averaging approach to generate a more accurate model, which is also used to derive a small-signal model. The proposed model is an important tool that yields better results when analyzing power budgeting, performing large-signal simulations, and designing controllers for TM-MICs via a more precise representation than classical averaging methods. Analyses are supported by simulations and experimental results. Third, this dissertation studies application of a decentralized controller on an MI-SEPIC. For an MIC, a multiple-input-multiple-output (MIMO) state-space representation can be derived by an averaging method. Based on the averaged MIMO model, an MIMO small-signal model can be generated. Both conventional method and modern multivariable frequency analysis are applied to the small-signal model of an MI-SEPIC to evaluate open-loop and closed-loop characteristics. In addition to verifying the nominal stability and nominal performance, this work evaluates robust stability and robust performance with the structured singular value. The robust performance test shows that a compromised performance may be expected under the decentralized control. Simulations and experimental results verify the theoretical analysis on stability and demonstrate that the decentralized PI controller could be effective to regulate the output of an MIC under uncertainties. Finally, this work studies the control of the MIMO dc-dc converter serving as an active distribution node in an intelligent dc distribution grid. The unified model of a MIMO converter is derived, enabling a systematical analysis and control design that allows this converter to control power flow in all its ports and to act as a power buffer that compensates for mismatches between power generation and consumption. Based on the derived high-order multivariable model, a robust controller is designed with disturbance-attenuation and pole-placement constraints via the linear matrix inequality (LMI) synthesis. The closed-loop robust stability and robust performance are tested through the structured singular value synthesis. Again, the desirable stability and performance are verified by simulations and experimental results.
Advanced Control Methodologies For Power Converter Systems
DOWNLOAD
Author : Wensheng Luo
language : en
Publisher: Springer Nature
Release Date : 2022-02-16
Advanced Control Methodologies For Power Converter Systems written by Wensheng Luo and has been published by Springer Nature this book supported file pdf, txt, epub, kindle and other format this book has been release on 2022-02-16 with Technology & Engineering categories.
This book aims to present some advanced control methodologies for power converters. Power electronic converters have become indispensable devices for plenty of industrial applications over the last decades. Composed by controllable power switches, they can be controlled by effective strategies to achieve desirable transient response and steady-state performance, to ensure the stability, reliability and safety of the system. The most popular control strategy of power converters is the linear proportional–integral–derivative series control which is adopted as industry standard. However, when there exist parameter changes, nonlinearities and load disturbances in the system, the performance of the controller will be significantly degraded. To overcome this problem, many advanced control methodologies and techniques have been developed to improve the converter performance. This book presents the research work on some advanced control methodologies for several types of power converters, including three-phase two-level AC/DC power converter, three-phase NPC AC/DC power converter, and DC/DC buck converter. The effectiveness and advantage of the proposed control strategies are verified via simulations and experiments. The content of this book can be divided into two parts. The first part focuses on disturbance observer-based control methods for power converters under investigation. The second part investigates intelligent control methods. These methodologies provide a framework for controller design, observer design, stability and performance analysis for the considered power converter systems.
Bi Directional Dcm Dc To Dc Converter For Hybrid Electric Vehicles
DOWNLOAD
Author : Michael James Pepper
language : en
Publisher:
Release Date : 2009
Bi Directional Dcm Dc To Dc Converter For Hybrid Electric Vehicles written by Michael James Pepper and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2009 with DC-to-DC converters categories.
With the recent revival of the hybrid vehicle much advancement in power management has been made. The most popular hybrid vehicle, the hybrid electric vehicle, has many topologies developed to realize this hybrid vehicle. From these topologies, as sub set was created to define a particular group of vehicles where the converter discussed in this thesis has the most advantage. This sub set is defined by two electric sources of power coupled together at a common bus. This set up presents many unique operating conditions which can be handled seamlessly by the DC-to-DC converter when designed properly. The DC-to-DC converter discussed in this thesis is operated in Discontinuous Conduction Mode (DCM) of operation because of its unique advantages over the Continuous Conduction Mode (CCM) operated converter. The most relevant being the reduction of size of the magnetic components such as inductor, capacitor and transformers. However, the DC-to-DC converter operated in DCM does not have the inherent capability of bi-directional power flow. This problem can be overcome with a unique digital control technique developed here. The control is developed in a hierarchical fashion to separate the functions required for this sub set of hybrid electric vehicle topologies. This layered approach for the controller allows for the seamless integration of this converter into the vehicle. The first and lowest level of control includes a group of voltage and controller regulators. The average and small signal model of these controllers were developed here to be stable and have a relatively fast recovery time to handle the transient dynamics of the vehicle system. The second level of control commands and organizes the regulators from the first level of control to perform high level task that is more specific to the operation of the vehicle. This level of control is divided into three modes called hybrid boost, hybrid buck and electric vehicle mode. These modes are developed to handle the specific operating conditions found when the vehicle is operated in the specific mode. The third level of control is used to command the second level of control and is left opened via a communication area network (CAN) bus controller. This level of control is intended to come from the vehicle's system controller. Because the DC-to-DC converter is operated in DCM, this introduces added voltage ripple on the output voltage as well as higher current ripple demand from the input voltage. Since this is generally undesirable, the converter is split into three phases and properly interleaved. The interleaving operation is used to counteract the effects of the added voltage and current ripple. Finally, a level of protection is added to protect the converter and surrounding components from harm. All protection is designed and implemented digitally in DSP.
Design And Characterization Of Differentially Enhanced Duty Ripple Control For Switching Dc Dc Converter
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2001
Design And Characterization Of Differentially Enhanced Duty Ripple Control For Switching Dc Dc Converter written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2001 with categories.
This dissertation proposes a new control method, Differentially Enhanced Duty Ripple Control (DE-DRC), for step-down converters in portable applications. With the development of handheld equipment, more power management blocks are required to support multi-functions in a single piece of equipment. The noisy working environment created by different application circuits and also the power supplies themselves, requires the power supplies to be very resistant to the effects of noise. At the same time, the powerful digital computing devices require the power supply to have a fast load transient response in order to achieve high computing efficiency and reliable working support. Because of the large duty ripple voltage with a big noise margin and the low pass filter effect of DDAs, the proposed DE-DRC has good noise immunity. The easily configured positive and negative DDA gains can separately adjust the high and low frequency portion of the loop transfer function, and push the control bandwidth to high frequency in order to achieve fast transient response. Because of a unique first order character of the inner duty ripple loop, this control can also completely eliminate the double pole peaking from output impedance and achieve ideal closed loop output impedance in the control bandwidth, which is preferred for adaptive voltage position designs. These characteristics make this new control method a good candidate for powering next generation digital computing devices in portable applications. Based on the DE-DRC control method, a monolithic Buck converter is designed and fabricated using TI's LBC7 process. It changes the on-time width according to the input and output voltage to keep the switching frequency relatively constant, and the control part and the power stage are integrated into one chip. The test results show good noise immunity performance and fast load transient response, as predicted.
Hybrid Switched Capacitor Power Converter Techniques
DOWNLOAD
Author : Nathan Miles Ellis
language : en
Publisher:
Release Date : 2020
Hybrid Switched Capacitor Power Converter Techniques written by Nathan Miles Ellis and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2020 with categories.
Power conversion is a necessity in almost all modern electric systems and machines: energy must be regulated and delivered in the intended manner if a system is to perform well, or at all. Power converters, the electronic circuits used to control this energy flow, have been a subject of intense study and rapid development in recent years and are widely acknowledged to be a fundamental enabler for modern day human societal capabilities. Many market sectors have strongly advocated for further development of energy conversion systems with improved efficiency and power density as these traits often directly dictate practical viability. While advancements in semiconductor device physics have yielded improved parts for use inconverter solutions, it is becoming apparent that there is additional massive potential and merit in revisiting fundamental converter topologies and circuit techniques. To date, power converters that use capacitors as their primary energy transfer elements (termed "switchedcapacitor" power converters) are far less ubiquitous than their switched-inductor counterparts, and seemingly for good reason: characteristics such as poor output regulation and intrinsic transient inrush currents that lead to inefficiency have largely prevented switched-capacitor topologies from gaining practical consideration in general power converter markets. Solutions to these negative attributes are strongly desired as capacitors can offer energy densities up to three orders of magnitude greater than inductors, with these energy transfer elements typically consuming the majority of a power converter's weight/volume. Recent work has demonstrated significant potential for hybrid switched-capacitor-inductor converter techniques: here, small inductive element(s) are used to eliminate the conventional drawbacks of a converter which is predominantly capacitor based. The hybridized approach helps unlock the full potential of capacitor-based converters and has been demonstrated to offer compelling results at the cost of added complexity. This work offers an exploration into a collection of state-of-the-art power converter techniques and topological methods, primarily within the field of hybridized switched-capacitor-inductor converters. The first two chapters give a background on fundamental considerations such as conventional loss mechanisms and the slow-switching-limit (SSL), as well as several established loss mitigation techniques. An integrated converter system and its associated functional blocks is then discussed in Chapters 3 and 4, exemplifying a hybridized two-stage converter and illustrating the implementation of several loss mitigation methods and practical circuit techniques. Next, several hybridized variations of the Dickson topology are discussed: this family of DC-DC converters is well suited for non-isolated large voltage conversion ratios. A number of these variants are proposed here for the first time, illustrating significant potential for further converter development. The steady-state bias points, resonant switching frequency, duty cycle and voltage ripple as a function of load are calculated for several example converters, including the non-trivial case of a converter undergoing split-phase operation and whose operating points exhibit a strong load dependence. To facilitate comparative analysis between topologies, a mathematical method is presented that characterizes the total energy density utilization of fly capacitors throughout a converter, accounting for large voltage ripple and iii highly nonlinear reverse-bias transitions. This analysis assists with optimal topology selection as energy density utilization directly dictates the required capacitor volume at a specified power level and switching frequency. An expanded family of fly capacitor networks is then introduced in Chapter 6; here it is shown that there are a large number of unexplored yet practical fly capacitor configurations that are eligible for use in hybridized converters. It is calculated that a 6-7 % reduction in capacitor volume can be achieved relative to conventional Dickson fly capacitor networks, while preserving the desirable characteristic of equal voltage ripple on its branches. N-phase and split-phase switching methods and their respective trade-offs are then discussed in detail, offering control techniques that allow a departure from conventional two-phase operation while retaining high-efficiency zero-voltage and zero-current switching (ZVS/ZCS) conditions. A Cockcroft-Walton prototype demonstrates both methods implemented on the same piece of hardware, significantly improving the efficiency range with respect to load and resulting in a state-of-the-art power density of 483.3 kW/liter (7, 920W/inch3). Next, a method termed "resonant charge redistribution" (RCR) is proposed that greatly reduces output capacitance (C[subscript OSS]) related switching losses in all switches of a complex switched-capacitor network. Despite little effort being put towards optimization, a prototype using RCR measures a 61 % reduction in total losses at light load for a near negligible 0.74 % increase in total solution volume. Lastly, resonant gate drive techniques are discussed. Here, within a proposed resonant gate-driver topology, a capacitive decoupling technique is demonstrated that allows power to be delivered to a "flying" high-side N-channel device which commutes between two variable voltages. The implemented prototype achieves up to a 72 % reduction in gating loss when switching over 20 MHz and with rise/fall times ≤ 7 ns. Combining several of the novel techniques described herein can result in near complete mitigation of all primary switching loss mechanisms observed throughout the complex structure of a switched-capacitor converter network. This relatively new field of hybridized converter design has already yielded converters with record-breaking performance, as is demonstrated here. With contemporary techniques, including those described in this work, the field of power electronics is on the cusp of seeing widespread dramatic improvements in energy handling capability, power density, specific power and efficiency at reduced cost, with huge potential for growth and improved energy consumption in both developed and emerging markets.
High Current Density Low Voltage Isolated Dc Dc Converters With Fast Transient Response
DOWNLOAD
Author : Liangbin Yao
language : en
Publisher:
Release Date : 2007
High Current Density Low Voltage Isolated Dc Dc Converters With Fast Transient Response written by Liangbin Yao and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2007 with DC-to-DC converters categories.
With the rapid development of microprocessor and semiconductor technology, industry continues to update the requirements for power supplies. For telecommunication and computing system applications, power supplies require increasing current level while the supply voltage keeps decreasing. For example, the Intel's CPU core voltage decreased from 2 volt in 1999 to 1 volt in 2005 while the supply current increased from 20A in 1999 to up to 100A in 2005. As a result, low-voltage high-current high efficiency dc-dc converters with high power-density are demanded for state-of-the-art applications and also the future applications. Half-bridge dc-dc converter with current-doubler rectification is regarded as a good topology that is suitable for high-current low-voltage applications. There are three control schemes for half-bridge dc-dc converters and in order to provide a valid unified analog model for optimal compensator design, the analog state-space modeling and small signal modeling are studied in the dissertation and unified state-space and analog small signal model are derived. In addition, the digital control gains a lot of attentions due to its flexibility and re-programmability. In this dissertation, a unified digital small signal model for half-bridge dc-dc converter with current doubler rectifier is also developed and the digital compensator based on the derived model is implemented and verified by the experiments with the TI DSP chip. In addition, although current doubler rectifier is widely used in industry, the key issue is the current sharing between two inductors. The current imbalance is well studied and solved in non-isolated multi-phase buck converters, yet few discusse this issue in the current doubler rectification topology within academia and industry. This dissertation analyze the current sharing issue in comparison with multi-phase buck and one modified current doubler rectifier topology is proposed to achieve passive current sharing. The performance is evaluated with half bridge dc-dc converter; good current sharing is achieved without additional circuitry. Due to increasing demands for high-efficiency high-power-density low-voltage high current topologies for future applications, the thermal management is challenging. Since the secondary-side conduction loss dominates the overall power loss in low-voltage high-current isolated dc-dc converters, a novel current tripler rectification topology is proposed. Theoretical analysis, comparison and experimental results verify that the proposed rectification technique has good thermal management and well-distributed power dissipation, simplified magnetic design and low copper loss for inductors and transformer. That is due to the fact that the load current is better distributed in three inductors and the rms current in transformer windings is reduced. Another challenge in telecommunication and computing applications is fast transient response of the converter to the increasing slew-rate of load current change. For instance, from Intel's roadmap, it can be observed that the current slew rate of the age regulator has dramatically increased from 25A/uS in 1999 to 400A/us in 2005. One of the solutions to achieve fast transient response is secondary-side control technique to eliminate the delay of optocoupler to increase the system bandwidth. Active-clamp half bridge dc-dc converter with secondary-side control is presented and one industry standard 16th prototype is built and tested; good efficiency and transient response are shown in the experimental section. However, one key issue for implementation of secondary-side control is start-up. A new zero-voltage-switching buck-flyback isolated dc-dc converter with synchronous rectification is proposed, and it is only suitable for start-up circuit for secondary-side controlled converter, but also for house-keeping power supplies and standalone power supplies requiring multi-outputs.