Download or read book Adaptive Control of a Step up Full bridge DC DC Converter for Variable Low Input Voltage Applications written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis shows the implementation of a novel control scheme DC-DC converter. The converter is a phase-shifted full-bridge PWM converter that is designed to operate as a front stage of a power conversion system where the input is a variable low voltage high current source. The converter is designed to step-up the low voltage input to an acceptable level that can be inverted to a 120/240 VAC 60Hz voltage for residential power. A DSP based adaptive control model is developed, taking into account line variations introduced by the input source while providing very good load dynamics for the converter in both discontinuous and continuous conduction modes. The adaptive controller is implemented using two voltage sensors that read the input and the output voltages of the converter. The controller's bandwidth is comparable to current mode control, without the need for an expensive current sensor, yet providing the noise immunity seen in voltage mode controllers. The intended input source was a fuel cell but in its absence a DC supply is utilized instead. The system is simulated for both discontinuous and continuous conduction modes and implemented and demonstrated for the continuous conduction mode. The test results are shown to match the simulation results very closely.
Download or read book Entire Load Efficiency and Dynamic Performance Improvements for DC DC Converters written by Osama A. Abdel-Rahman and published by . This book was released on 2007 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: Demands for DC-DC converters are continuously increasing for the application in many areas such as telecommunications, cellular telephones, networking products, notebook and desktop computers, industrial instrumentation, and automotive electronics. These areas are continually being upgraded with regard to their specifications and power requirements; this puts the emphasis on power electronics and power management. DC-DC converters are able to supply energy at high standards and specifications, which leads DC-DC converters to be continually upgraded in order to fulfill other application requirements such as efficiency, dynamic performance, thermo, noise and size.
Download or read book Electric Vehicles written by Seref Soylu and published by BoD – Books on Demand. This book was released on 2011-09-12 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, modeling and simulation of electric vehicles and their components have been emphasized chapter by chapter with valuable contribution of many researchers who work on both technical and regulatory sides of the field. Mathematical models for electrical vehicles and their components were introduced and merged together to make this book a guide for industry, academia and policy makers.
Download or read book Dynamics and Control of DC DC Converters written by Farzin Asadi and published by Springer Nature. This book was released on 2022-05-31 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: DC-DC converters have many applications in the modern world. They provide the required power to the communication backbones, they are used in digital devices like laptops and cell phones, and they have widespread applications in electric cars, to just name a few. DC-DC converters require negative feedback to provide a suitable output voltage or current for the load. Obtaining a stable output voltage or current in presence of disturbances such as: input voltage changes and/or output load changes seems impossible without some form of control. This book tries to train the art of controller design for DC-DC converters. Chapter 1 introduces the DC-DC converters briefly. It is assumed that the reader has the basic knowledge of DC-DC converter (i.e., a basic course in power electronics). The reader learns the disadvantages of open loop control in Chapter 2. Simulation of DC-DC converters with the aid of Simulink® is discussed in this chapter as well. Extracting the dynamic models of DC-DC converters is studied in Chapter 3. We show how MATLAB® and a software named KUCA can be used to do the cumbersome and error-prone process of modeling automatically. Obtaining the transfer functions using PSIM® is studied as well. These days, softwares are an integral part of engineering sciences. Control engineering is not an exception by any means. Keeping this in mind, we design the controllers using MATLAB® in Chapter 4. Finally, references are provided at the end of each chapter to suggest more information for an interested reader. The intended audiencies for this book are practice engineers and academians.
Download or read book High Frequency Isolated Bidirectional Dual Active Bridge DC DC Converters with Wide Voltage Gain written by Deshang Sha and published by Springer. This book was released on 2018-05-17 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by experts, this book is based on recent research findings in high-frequency isolated bidirectional DC-DC converters with wide voltage range. It presents advanced power control methods and new isolated bidirectional DC-DC topologies to improve the performance of isolated bidirectional converters. Providing valuable insights, advanced methods and practical design guides on the DC-DC conversion that can be considered in applications such as microgrid, bidirectional EV chargers, and solid state transformers, it is a valuable resource for researchers, scientists, and engineers in the field of isolated bidirectional DC-DC converters.
Download or read book Adaptive Control Methods for DC DC Switching Power Converters written by VaraPrasad Arikatla and published by . This book was released on 2011 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tight regulation of the output voltage is often required in many power supply applications, despite the highly dynamic nature of the loads. This is conventionally obtained by the design of high bandwidth feedback loop or recently by using adaptive control methods. The control loop is designed with specified safe bandwidth and gain and phase margins such that it maintains stable operation under variable conditions and parameters. However, this results in a compromise between achievable dynamic performance and robustness of control loop. The large variations in operating points and load makes the system design challenging. The tight regulation requirements, in addition to size and weight requirements, are getting stricter by time, which makes it necessary to investigate new control concepts in order to meet these requirements. Not meeting the tight regulation requirements may result in either the malfunctioning of the device (load) being powered or the destruction of that device. This work focuses on the development and implementation of adaptive control methods that result in the improvement of the dynamic performance of power converter, by utilizing the flexibility of digital controllers to realize advanced control schemes. Four different methods are proposed that improve the dynamic performance of converter without compromising the steady-state performance. A Sensorless Adaptive Voltage Positioning (SLAVP) control scheme is proposed in Chapter 2, in order to realize Adaptive Voltage Positioning (AVP) control without the need for load or inductor current sensing and high-resolution high-speed Analog-to-Digital Converter (ADC) sampling. The SLAVP control law utilizes the readily available error signal of the conventional voltage-mode closed-loop compensated controller, or in other words the duty cycle of a DC-DC buck converter, in order to realize AVP control. The elimination of the need for high-speed and accurate sensing and sampling of currents using the proposed SLAVP control reduces the size and cost of the digital controller, reduces the power losses associated with current sensing and sampling, and simplifies hardware design, apart from improving dynamic performance. In Chapter 3, an Adaptive Digital PID (AD-PID) controller scheme is proposed. The controller adaptively adjusts the integral constant (K_i) and the proportional constant (K_p) of the compensator following a new control law. The control law is a function of the magnitude change in the error signal and its peak value during dynamic transients. The proposed AD-PID controller adaptively detects the peak value of the error signal which is a function of the transient nature and magnitude and utilize it in the control law such that no ocillations are generated as a result of the adaptive operation. As a result, the dynamic output voltage deviation and the settling time of the output voltage are reduced. A novel Compensator Error Observe and Modulate method (CEO & M) for online closed-loop-compensator auto-tuning of digital power controller is proposed in Chapter 4. The proposed method is relatively simple and does not require the knowledge and/or measurement of the power stage or closed-loop frequency response. Moreover, the proposed method does not depend on conventional design methods and the associated rule of thumb design criteria in order to tune closed-loop feedback controllers of power converter for high, and possibly optimum, dynamic performance. Furthermore, two approaches for dynamic variable switching frequency digital control scheme under dynamic transients are proposed in Chapter 5 in order to improve the dynamic performance of the DC-DC switching power converter. The proposed controller varies the switching frequency of the converter, higher or lower than the steady-state frequency, during the transient as a function of peak and magnitude of error signal depending on the amount and type of the transient. Finally, Chapter 6 summarizes this work and provides conclusions before discussing future related research direction.
Download or read book Average Current Mode Control of DC DC Power Converters written by Marian K. Kazimierczuk and published by John Wiley & Sons. This book was released on 2022-03-14 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: AVERAGE CURRENT-MODE CONTROL OF DC-DC POWER CONVERTERS An authoritative one-stop guide to the analysis, design, development, and control of a variety of power converter systems Average Current-Mode Control of DC-DC Power Converters provides comprehensive and up-to-date information about average current-mode control (ACMC) of pulse-width modulated (PWM) dc-dc converters. This invaluable one-stop resource covers both fundamental and state-of-the-art techniques in average current-mode control of power electronic converters???featuring novel small-signal models of non-isolated and isolated converter topologies with joint and disjoint switching elements and coverage of frequency and time domain analysis of controlled circuits. The authors employ a systematic theoretical framework supported by step-by-step derivations, design procedures for measuring transfer functions, challenging end-of-chapter problems, easy-to-follow diagrams and illustrations, numerous examples for different power supply specifications, and practical tips for developing power-stage small-signal models using circuit-averaging techniques. The text addresses all essential aspects of modeling, design, analysis, and simulation of average current-mode control of power converter topologies, such as buck, boost, buck-boost, and flyback converters in operating continuous-conduction mode (CCM). Bridging the gap between fundamental modeling methods and their application in a variety of switched-mode power supplies, this book: Discusses the development of small-signal models and transfer functions related to the inner current and outer voltage loops Analyzes inner current loops with average current-mode control and describes their dynamic characteristics Presents dynamic properties of the poles and zeros, time-domain responses of the control circuits, and comparison of relevant modeling techniques Contains a detailed chapter on the analysis and design of control circuits in time-domain and frequency-domain Provides techniques required to produce professional MATLAB plots and schematics for circuit simulations, including example MATLAB codes for the complete design of PWM buck, boost, buck-boost, and flyback DC-DC converters Includes appendices with design equations for steady-state operation in CCM for power converters, parameters of commonly used power MOSFETs and diodes, SPICE models of selected MOSFETs and diodes, simulation tools including introductions to SPICE, MATLAB, and SABER, and MATLAB codes for transfer functions and transient responses Average Current-Mode Control of DC-DC Power Converters is a must-have reference and guide for researchers, advanced graduate students, and instructors in the area of power electronics, and for practicing engineers and scientists specializing in advanced circuit modeling methods for various converters at different operating conditions.
Download or read book Coordination and Control of Power Converters in Modern Power Systems written by Hao Tian and published by Frontiers Media SA. This book was released on 2023-12-12 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design of Area and Power efficient Dual output Switched capacitor DC DC Converters written by Zhe Hua and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Power management integrated circuits have found wide applications in all battery-powered electronic systems like smartphones, wireless sensors, etc., to convert a time-varying unregulated battery voltage to constant regulated DC output voltages for different internal functional blocks of the system. With the increase in the complexity of today’s electronic systems, a multiple-output power management system is desired to optimize the power consumption of each loading block such that the power dissipation of the whole system can be minimized to extend the battery run-time. Driven by the demands for high power efficiency and high area efficiency in generating multiple outputs for energy-harvesting and portable applications, the multiple-output switched-capacitor (SC) DC-DC converter is becoming a popular candidate as it does not require any costly and bulky inductor for energy storage, thereby minimizing the overall converter volume and EMI noise. Moreover, flying capacitors as energy-storage components and power transistors as energy-transfer paths in the multiple-output SC DC-DC converters can be shared by different outputs such that the number of required flying capacitors and power transistors can be minimized to optimize both area efficiency and energy density. In the first part of this research, a reconfigurable step-up dual-output SC DC-DC regulator is introduced, analyzed and verified for low power energy-harvesting applications. A sub-harmonic adaptive-on-time (SHAOT) control scheme is proposed to improve the light-load power efficiency under different load currents, maintain low output ripples under different input voltages, provide predictable output noise spectrum, and minimize output cross regulation between both outputs in the SC DC-DC regulator. In the second part of this research, a battery-connected reconfigurable step-down dual-output SC DC-DC regulator is developed to deliver a maximum load of 1.2A for portable applications. With flying-capacitor sharing and an all-nMOS power stage, the proposed dual-output SC power stage is efficient in both chip and board areas. A switch-resistance-modulation (SRM) control scheme is also proposed to provide small output voltage ripples with a small load capacitance under 100s-of-mA load and to minimize output cross regulation between two outputs under large load-step variations.
Download or read book A Line and Load Independent Zero Voltage Switching DC DC Full Bridge Converter Topology written by Wen Kang and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Full bridge dc/de converter topology is extensively applied in medium to high power conversion. In a power level up to 3 kW, the full bridge converter now employs MOSFET switches. High efficiency, high power density, high reliability and low EMI are some of the most desirable features in these applications, particularly for computer and telecom systems. To achieve these features, soft switching techniques are normally employed. However, the conventional soft switching full bridge converter topologies would either lose the soft switching at some operating conditions, or become rather complex in design and implementation for a few kilo watts applications. This thesis presents and analyzes an improved zero voltage switching dc/dc full bridge converter topology. The proposed topology employs asymmetrical auxiliary circuits that consist of only a few passive components. However, the advantage of the proposed topology is significant: it achieves soft switching independent of line and load conditions. Detailed steady state and dynamic analyses are performed to understand the operating principle of the proposed topology and its performance. A dc blocking capacitor is essential to prevent the current sense transformer from saturation, and the study of this thesis shows that contrary to the conventional pulse width modulated full bridge converter, the peak current mode control can still be used along with the blocking capacitor in a phase shift full bridge converter. Design procedure for industrial application is presented. Experimental and simulation results of a prototype 500 W 350-400 Vdc to 55 Vdc converter operating at 100 kHz verify the analysis and design, and show an overall efficiency of greater than 97% at full load.
Download or read book A HIGH STEP UP THREE PORT DC DC CONVERTER FOR STAND ALONE PV BATTERY POWER SYSTEMS WITH GRID CONNECTED MODE written by N. MALLA REDDY and published by Lulu.com. This book was released on 2016-06-13 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: Integrated multiport converters for interfacing several power sources and storage devices are widely used in recent years. Instead of using individual power electronic converters for each of the energy sources, multiport converters have the advantages including less components, lower cost, more compact size, and better dynamic performance. In many cases, at least one energy storage device should be incorporated. So, it is very important for the port connected to the energy storage to allow bidirectional power flow.
Download or read book Adaptive Efficiency Optimization for Digitally Controlled DC DC Converters written by Wisam M. Al-Hoor and published by . This book was released on 2009 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: The design optimization of DC-DC converters requires the optimum selection of several parameters to achieve improved efficiency and performance. Some of these parameters are load dependent, line dependent, components dependent, and/or temperature dependent. Designing such parameters for a specific load, input and output, components, and temperature may improve single design point efficiency but will not result in maximum efficiency at different conditions, and will not guarantee improvement at that design point because of the components, temperature, and operating point variations. The ability of digital controllers to perform sophisticated algorithms makes it easy to apply adaptive control, where system parameters can be adaptively adjusted in response to system behavior in order to achieve better performance and stability. The use of adaptive control for power electronics is first applied with the Adaptive Frequency Optimization (AFO) method, which presents an auto-tuning adaptive digital controller with maximum efficiency point tracking to optimize DC-DC converter switching frequency. The AFO controller adjusts the DC-DC converter switching frequency while tracking the converter minimum input power point, under variable operating conditions, to find the optimum switching frequency that will result in minimum total loss and thus the maximum efficiency. Implementing variable switching frequencies in digital controllers introduces two main issues, namely, limit cycle oscillation and system instability. Dynamic Limit Cycle Algorithms (DLCA) is a dynamic technique tailored to improve system stability and to reduce limit cycle oscillation under variable switching frequency operation. The convergence speed and stability of AFO algorithm is further improved by presenting the analysis and design of a digital controller with adaptive auto-tuning algorithm that has a variable step size to track and detect the optimum switching frequency for a DC-DC converter. The Variable-Step-Size (VSS) algorithm is theoretically analyzed and developed based on buck DC-DC converter loss model and directed towered improving the convergence speed and accuracy of AFO adaptive loop by adjusting the converter switching frequency with variable step size. Finally, the efficiency of DC-DC converters is a function of several variables. Optimizing single variable alone may not result in maximum or global efficiency point. The issue of adjusting more than one variable at the same time is addressed by the Multivariable Adaptive digital Controller (MVAC). The MVAC is an adaptive method that continuously adjusts the DC-DC converter switching frequency and dead-time at the same time, while tracking the converter minimum input power, to find the maximum global efficiency point under variable conditions. In this research work, all adaptive methods were discussed, theoretically analyzed and its digital control algorithm along with experimental implementations were presented.
Download or read book New Topologies and Modulation Schemes for Soft Switching Isolated DC DC Converters written by Zhiqiang Guo and published by Springer Nature. This book was released on 2019-09-20 with total page 243 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a series of new topologies and modulation schemes for soft-switching in isolated DC–DC converters. Providing detailed analyses and design procedures for converters used in a broad range of applications, it offers a wealth of engineering insights for researchers and students in the field of power electronics, as well as stimulating new ideas for future research.
Download or read book Integrated Switching DC DC Converters with Hybrid Control Schemes written by and published by . This book was released on 2009 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book DC DC Converter Topologies written by Gerry Moschopoulos and published by John Wiley & Sons. This book was released on 2023-12-18 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: DC-DC Converter Topologies A comprehensive look at DC-DC converters and advanced power converter topologies for all skills levels As it can be rare for source voltage to meet the requirements of a Direct Current (DC) load, DC-DC converters are essential to access service. DC-DC power converters employ power semiconductor devices (like MOSFETs and IGBTs) as switches and passive elements such as capacitors, inductors, and transformers to alter the voltage provided by a DC source into the necessary DC voltage as is required by a DC load. This source can be a battery, solar panels, fuel cells, or a DC bus voltage fed by rectified AC utility voltage. As the many components of DC-DC converters can be differently arranged into circuit structures called topologies, there are as many possible circuit topologies as there are possible combinations of circuit elements. Focusing on DC-DC switch-mode power converters ranging from 50 W to 10kW, DC-DC Converter Topologies provides a survey of all converter topology types within this power range. General principles are described for each topology type using a representative converter as an example. Variations that can be found that differ from the example are then examined, with a helpful discussion of comparisons when relevant. A broad range of topics is covered within the book, from simple, low-power converters to complex, high-power converters and everywhere in between. DC-DC Converter Topologies readers will also find: A detailed discussion of four key DC-DC converter topologies Description of isolated two-switch pulse-width modulated (PWM) topologies including push-pull, half-bridge, and interleaved converters An exploration of high-gain converters such as coupled inductors, voltage multipliers, and switched capacitor converters This book provides the tools so that a non-expert will be equipped to deal with the vast array of DC-DC converters that presently exist. As such, DC-DC Converter Topologies is a useful reference for electrical engineers, professors, and graduate students studying in the field.
Download or read book Investigation and Application of High efficiency Large step down Power Conversion Architectures written by Samantha Joellyn Gunter and published by . This book was released on 2016 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, we introduce two large-step-down dc-dc converter architectures that are designed to provide zero-voltage switching of the power devices. While the techniques used in these converters can be used in a wide range of applications, the operating voltage and power levels used in this thesis are for data centers, where dc distribution power delivery is expected to see its first deployment. The nominal 380 V bus voltage will need to be converted to 12 V using a high-efficiency dc-dc converter that can deliver several hundred watts of power to each rack to power the servers. The converters are expected to operate efficiently across a wide input voltage range of 260 V to 410 V and down to powers in the tens of watts range. The first converter architecture is based on the concept of an Impedance Control Network (ICN) resonant converter. Using phase-shift control along with a specifically designed impedance network, this converter can maintain resistive loading of the inverters as the input voltage varies. To back down in power, the converter can be efficiently operated using burst (on/off) mode control. To deliver lower power, we introduce an additional control technique using Variable Frequency Multiplier (VFX) inverters and/or rectifiers. The second converter architecture combines the properties of an active bridge converter with multiple stacked inverters, a multi-winding single core transformer, and a reconfigurable rectifier. The stacked inverter topology improves the range of powers over which zero-voltage switching can be achieved. The multi-winding transformer and reconfigurable rectifier further extend the efficient operating range to very low powers by reducing core loss and increasing zero-voltage switching capability. Both proposed architectures are suitable for large-step-down, wide-input voltage, wide-output power applications such as dc-dc converters for dc distribution.
Download or read book Pulsewidth Modulated DC to DC Power Conversion written by Byungcho Choi and published by John Wiley & Sons. This book was released on 2021-10-19 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt: ORGANIC REACTIONS CYCLIZATION REACTIONS OF NITROGEN-CENTERED RADICALS Stuart W. McCombie, Béatrice Quiclet-Sire, and Samir Z. Zard TRANSITION-METAL-CATALYZED AMINOOXYGENATION OF ALKENES Sherry R. Chemler, Dake Chen, Shuklendu D. Karyakarte, Jonathan M. Shikora, and Tomasz Wdowik
