检索结果-内蒙古大学图书馆

37th Annual IEEE Applied Power Electronics Conference and Exposition (APEC)

作者： Chilukuri, Gopi Reddy Chatterjee, Dipayan Mallik, Ranajay Kapat, Santanu Indian Inst Technol Kharagpur Dept Elect Engn Embedded Power Management Lab Kharagpur 721302 West Bengal India STMicroelectron Private Ltd Syst Lab Delhi India

ISBN: (纸本)9781665406895;9781665406888

LLC converters offer high efficiency, low electromagnetic interference (EMI) and high power density using soft switching, which makes them an attractive solution for data center, electric vehicle and renewable energy applications. While operating over a wide range of input/output voltages and power level, the switching frequency fsw may vary around the resonant frequency f(r) under pulse frequency modulation (PFM) or may be maintained at f(r) using phase shift modulation (PSM) within some limits. Nevertheless, for varying voltage gain and power level, the LLC converter often undergoes structural changes with reduced system dimension, making it difficult in identifying suitable modeling techniques. Small-signal models using first-order-harmonic approximation (FHA) are widely used, which work fine while operating well near f(r);however, the model validity remains a serious concern with increasing harmonic contents when f(sw) deviates from f(r). This digest proposes a unified discrete-time (DT) framework for the derivation of accurate large-signal and small-signal models of an LLC converter by taking into consideration the dimensional change over the entire frequency range. Large-signal models are shown to perfectly capture the actual switch simulation for three possible configurations depending on the relationship between f(sw) and f(r). A 2.5 kW LLC resonant converter hardware prototype is developed and the accuracy of the proposed large-signal models is validated using experimental results, which show close agreement with the analytical prediction. Finally, the proposed discrete-time small-signal models are verified with the SIMetrix/SIMPLIS simulation in the frequency domain and are also compared with traditional Extended Describing Function (EDF) method.

关键词： LLC resonant converter discrete-time model pulse-frequency modulation large-signal model small-signal model extended describing function

来源：评论

学校读者我要写书评

暂无评论

Control Characteristics of Zero-Current-Switching Quasi-Resonant Buck Converter under Variation of Resonant Circuit and Load Parameters 19

Control Characteristics of Zero-Current-Switching Quasi-Reso...

引用

19th International Conference on Smart Technologies (IEEE EUROCON)

作者： Dymerets, Andrii, V Yershov, Roman D. Gorodny, Alexey N. Revko, Anatoliy S. Denisov, Yurii O. Natl Univ Chernihiv Polytech Dept Elect Automat Robot & Mechatron Chernihiv Ukraine

ISBN: (纸本)9781665432993

The investigation of resonant circuit parameters influence on control characteristics in buck half-wave quasi-resonant converter is presented. The dependences of the voltage conversion ratio, control pulses duration, and operating frequency of the converter under variation of resonant circuit parameters and control pulses duty cycle are obtained by dint of numeric simulation. The dependences of these characteristics under variation of load impedance and control duty cycle are also obtained. The research results allow simplifying the development flow and construction of robust table-based or adaptive control systems for quasi-resonant converters.

关键词： half-wave quasi-resonant buck converter zero-current-switching ZCS resonant circuit pulse-frequency modulation PFM control characteristics

来源：评论

学校读者我要写书评

暂无评论

DYNAMIC pulse-frequency modulation IN OBJECTS CONTROL WITH DELAY

引用

ASIAN JOURNAL OF CONTROL 2012年第6期14卷 1662-1668页

作者： Aitchanov, B. Kh. Kurmanov, B. K. Umarov, T. F. Kazakh Natl Tech Univ KazNTU Dept Tech Cybernet Alma Ata 050013 Kazakhstan KBTU Dept Comp Engn Alma Ata 050000 Kazakhstan

This paper describes the development of the method of building mathematical models of dynamic pulse-frequency systems of automatic control of objects with random parameters and delay in the class of stochastic functional series of Voltaire and differential equations of Ito. In order to obtain mathematical descriptions of the system we have used homogenous models equivalent and majorizing processes in which are identical with the processes of the real stochastic dynamic pulse-frequency system of control of objects with delay. Obtained mathematical models of stochastic dynamic pulse-frequency systems of automatic control of objects with delay in the class of functional series of Voltaire and differential equations of Ito represent a further development of methods of description of "input-output" systems and "state space" and serve as a basis for developing methods of analysis and synthesis of the given class of automatic control systems.

关键词： pulse-frequency modulation objects with constant delay time control systems majorizing system homogenous model

来源：评论

学校读者我要写书评

暂无评论

Fully-Integrated Reconfigurable Charge Pump With Two-Dimensional frequency modulation for Self-Powered Internet-of-Things Applications

引用

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS 2020年第11期67卷 4132-4141页

作者： Cheng, Hao-Chung Tsai, Wen-Yuan Chen, Po-Han Chen, Po-Hung Natl Chiao Tung Univ Inst Elect Hsinchu 30010 Taiwan

In this paper, we propose a fully-integrated reconfigurable charge pump in a 0.18-mu m CMOS process;this converter is applicable for self-powered Internet-of-Things applications. The proposed charge pump uses a two-dimensional frequency modulation technique, which combines both the pulse-frequency modulation (PFM) and pulse-skip modulation (PSM) techniques. The PFM technique adjusts the operating frequency of the converter according to the variations in the load current, and the PSM technique regulates the output voltage. The proposed two-dimensional frequency modulation technique can improve the overall power conversion efficiency and the response time of the converter under light load conditions. A photovoltaic cell was chosen as the input source of the proposed converter. To adapt to the variations in the output voltage of a photovoltaic cell under different light illumination intensities, we built a reconfigurable converter core with multiple power conversion ratios of 2, 2.5, and 3 for the regulated output voltage of 1.2 V when the input voltage ranged from 0.53 V to 0.7 V. Our measurement results prove that the proposed capacitive power converter could achieve a peak power conversion efficiency of 80.8%, and the efficiency was more than 70% for the load current that ranged from 10 mu A to 620 mu A.

关键词： Charge pump Internet-of-Things (IoT) reconfigurable pulse-frequency modulation pulse-skip modulation two-dimensional frequency modulation

来源：评论

学校读者我要写书评

暂无评论

Dynamic Characteristics of Zero-Current-Switching Quasi-Resonant Buck Converter under Variation of Resonant Circuit and Load Parameters 40

Dynamic Characteristics of Zero-Current-Switching Quasi-Reso...

引用

IEEE 40th International Conference on Electronics and Nanotechnology (ELNANO)

作者： Dymerets, Andrii, V Yershov, Roman D. Gorodny, Alexey N. Denisov, Yurii O. Boiko, Serhii Kuznetsov, Vitaliy Chernihiv Natl Univ Technol Dept Elect Automat Robot & Mechatron Chernihiv Ukraine Kharkiv Natl Univ Internal Affairs Kremenchuk Flight Coll Dept Energy Supply & Management Syst Kremenchuk Ukraine Natl Met Acad Ukraine Dept Elect Engn & Electromech Dnipro Ukraine

ISBN: (纸本)9781728197135

The investigation of resonant circuit parameters influence on dynamic characteristics and electromagnetic processes in half-wave quasi-resonant buck converter is presented. The dependences of transistor non-zero conductivity duration, transistor switching-off current value, transistor voltage and current peak values under variation of resonant inductance and resonant capacitance are obtained by dint of simulation. The dependences of these characteristics and output voltage under variation of active and reactive part of load impedance are also received. All above allow simplifying construction of robust table-based control system for similar converters.

关键词： half-wave quasi-resonant buck converter resonant circuit pulse-frequency modulation PFM zero-current-switching ZCS

来源：评论

学校读者我要写书评

暂无评论

A Low Output Voltage Ripple Fully-Integrated Switched-Capacitor DC-DC Converter 62

A Low Output Voltage Ripple Fully-Integrated Switched-Capaci...

引用

62nd IEEE International Midwest Symposium on Circuits and Systems (MWSCAS)

作者： Veerabathini, Anurag Furth, Paul M. New Mexico State Univ Klipsch Sch Elect & Comp Engn Las Cruces NM 88003 USA

ISBN: (纸本)9781728127880

A fully-integrated switched-capacitor (SC) DC-DC converter that steps down 3.3 V to 1.5 V with a peak efficiency of 68% is implemented in a 2P3M 0.6-mu m CMOS process with a 555 pF poly-poly flying capacitor and a 1.34 nF MOS tank capacitor. This paper demonstrates a means of applying a low-frequency input clock as part of a time-interleaving technique for a symmetric charge-discharge topology that reduces the output voltage ripple. Burst-mode pulse-frequency modulation is used to maintain high efficiency over a wide range of load currents. A maximum 27 mV in output voltage ripple is measured for load current between 590 mu A and 8 mA. In response to a load transient from 560 mu A to 5.1 mA, the SC converter shows no undershoot and an overshoot of only 19 mV. Measured load regulation is 13.2 mV/mA.

关键词： Switched-capacitor converter pulse-frequency modulation time-interleaving poly-poly capacitor burst-mode PFM fully-integrated SC converter capacitor structures

来源：评论

学校读者我要写书评

暂无评论

Self-adaptation load change control strategy for three-phase staggered parallel LLC resonant converter

引用

IET POWER ELECTRONICS 2018年第14期11卷 2338-2345页

作者： Feng Xingtian Wan Manman Tao Yuanyuan Shao Kang China Univ Petr East China Coll Informat & Control Engn 66 West Changjiang Rd Qingdao 266580 Peoples R China China Inst Atom Energy Beijing 102413 Peoples R China

The resonant frequency of LLC resonant converter has a wide range of switching frequency due to load changes and it easily enters high frequency band during light load and no-load conditions. Therefore, this study proposes a self-adaptation load change control strategy. According to different load conditions, the converter automatically selects the best control mode among three control methods, which are pulse-frequency modulation, symmetrical pulse-width modulation and burst. By fully utilising the characteristics of the load-independent point in the gain curve and the relationship between the resonant current and the load, the switching conditions between the control strategies are further designed and optimised. In addition, based on the adaptive load change control strategy, the design value of k (the ratio of the excitation inductor to the resonant inductance of the transformer) is increased, which solved the disadvantage of large change of the switch range. And the converter can not only effectively control the output voltage during light load, but also works in the soft-switching state, which can improve the working efficiency of the converter to above 91%. Finally, taking a three-phase staggered parallel LLC resonant converter as the research object, an experimental prototype was developed based on SiC devices to verify the correctness and rationality of the proposed control strategy.

关键词： inductors zero voltage switching resonant power convertors zero current switching pulse frequency modulation pulse width modulation adaptive control load regulation optimisation control system synthesis self-adaptation load change control strategy pulse-frequency modulation symmetrical pulse-width modulation burst load-independent point switching conditions resonant inductance resonant frequency high frequency band no-load conditions light load condition three-phase staggered parallel LLC resonant converter gain curve resonant current adaptive load change control strategy design control strategies optimisation excitation inductor output voltage soft-switching state experimental prototype SiC devices

来源：评论

学校读者我要写书评

暂无评论

Clock pulse modulation for ripple reduction in buck-converter circuits

引用

CHAOS SOLITONS & FRACTALS 2018年 111卷 138-145页

作者： Ito, Daisuke Asahara, Hiroyuki Kousaka, Takuji Ueta, Tetsushi Gifu Univ Dept Elect Elect & Comp Engn 1-1 Yanagido Gifu Gifu 5011193 Japan Okayama Univ Sci Fac Engn Dept Elect & Elect Engn Kita Ku 1-1 Ridai Cho Okayama Okayama 7000005 Japan Chukyo Univ Fac Engn Dept Elect & Elect Engn Showa Ku 101-2 Yagoto Honmachi Nagoya Aichi 4668666 Japan Tokushima Univ Ctr Adm Informat Technol 2-1 Minamijyousanjima Cho Tokushima Tokushima 7708506 Japan

DC-DC switching converters which are frequently treated as hybrid dynamical systems exhibit complex behavior due to nonlinear and interrupt characteristics. For synchronous buck-converters, we propose a method to control chaotic behavior by pulse-frequency modulation. An input voltage, a duty ratio of PWMs, and so on, affect to the regulation characteristics of converters directly, but a frequency of PWMs is determined by the frequency characteristics of the converter and is set as a fixed value. The proposed chaos-control method suppresses chaotic responses by slightly perturbing the pulse frequency alone, therefore our method can stabilize unstable periodic orbits without influence on the voltage regulation scheme. To simplify the feedback controller, the condition of dimension reduction for the controlling gain vector is derived. The proposed controller achieves the stabilization without a current sensor. Numerical simulation and circuit implementation demonstrate the validity of this method. (C) 2018 Elsevier Ltd. All rights reserved.

关键词： Controlling chaos Buck converter pulse-frequency modulation

来源：评论

学校读者我要写书评

暂无评论

Off-Time Control of LLC Resonant Half-Bridge Converter to Prevent Audible Noise Generation Under a Light-Load Condition

引用

IEEE TRANSACTIONS ON POWER ELECTRONICS 2018年第10期33卷 8808-8817页

作者： Yoon, Ho-Young Lee, Hyeon-Seok Ham, Seok-Hyeong Choe, Hyung-Jin Kang, Bongkoo Pohang Univ Sci & Technol Dept Elect Engn Pohang 37673 South Korea LG Display Co Ltd Paju 10845 South Korea

This paper presents a control method that can prevent audible noise generation in an LLC resonant half-bridge dc-dc converter under a light-load condition, while achieving the same input voltage range and power-conversion efficiency eta(e) as the burst-control method that generates an audible noise. The proposed method reduces switching and conduction losses at light load by skipping several pairs of switch-control pulses, while varying the switching frequency less than the normal-control method does. This skip-control method enables the LLC resonant converter to have a large magnetizing inductance, and to have high eta(e) over a wide range of load variation. At an input voltage of 385 V, an output voltage of 24 V, and a resonant frequency of 180 kHz, the proposed method achieved eta(e) >= 85.46% for an output power range of 7.2-360 W;the highest eta(e) was 96.08% at P-o = 336 W.

关键词： DC-DC power conversion digital control onoff control pulse-frequency modulation pulse width modulated power converters resonant power conversion

来源：评论

学校读者我要写书评

暂无评论

Dual-phase DC-DC buck converter with light-load performance enhancement for portable applications

引用

IET POWER ELECTRONICS 2018年第4期11卷 719-726页

作者： Zhang, Shuyu Zhao, Menglian Wu, Xiaobo Zhang, Haozhou Zhejiang Univ Inst VLSI Design Hangzhou 310027 Zhejiang Peoples R China

In modern portable devices, except during short periods of busy time, application processors work at low-power state most of the time to prolong battery life. Thus, high efficiency and low consumption are essential for their power management under light-load conditions. This study presents a dual-phase DC-DC buck converter with light-load performance enhancement for power supply. As load decreases, the converter could transfer the adaptive-on-time-based control strategy from pulse-width modulation to pulse-frequency modulation to enhance efficiency. An extra power-save mode is introduced into design to minimise the power consumption at extremely light load. Besides, a novel current-balance circuit with additional offset elimination block is implemented, which results in equal distribution of load current between phases over wide load range. Moreover, instead of a conventional high precision and fast response comparator, a simple comparator with self-calibration is used in zero-current switching circuit to reduce design complexity, as well as to improve light-load efficiency. The converter is fabricated in 0.18-mu m Globalfoundry CMOS process. Experimental results show that91% peak efficiency and 6 mu A standby quiescent current is achieved. With the aid of mode switching, current-balance and zero-current switching, the light-load performance enhancement is verified by measurements.

关键词： DC-DC power convertors PWM power convertors pulse frequency modulation comparators (circuits) calibration switching convertors CMOS integrated circuits zero current switching dual-phase DC-DC buck converter light load performance enhancement portable device application power management adaptive-on-time-based control strategy pulse-width modulation pulse-frequency modulation extra power-save mode power consumption current-balance circuit offset elimination block comparator self-calibration zero-current switching circuit Globalfoundry CMOS process zero-current switching load current distribution size 0.18 mum efficiency 91 percent current 6 muA

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：