A structural approach to synthesizing,analyzing, and modeling quasi‐resonant converters

This paper presents a structural approach to synthesizing, analyzing, and modeling quasi‐resonant converters (QRCs) based on the concept of basic converter units (BCUs). Typical QRCs include the well‐known topologies of buck, boost, buck‐boost, Cuk, Zeta, and Sepic. With proper reconfiguration, these QRCs can be synthesized from either buck‐QRC BCU or boost‐QRC BCU plus certain linear networks. Thus, the BCUs and general configurations of the converters can be identified. Analysis of steady state operation and derivation of small‐signal models for the converters then can be conveniently performed from the general configurations, reducing the complexity significantly. Moreover, the proposed structural approach can explore more physical insights into the converters in a family, and can reveal more relationships among converters over conventional approaches. Copyright © 2011 John Wiley & Sons, Ltd.     

Application of duality principle to synthesis of single‐stage power‐factor‐correction voltage regulators

The duality principle is applied to derive new single‐stage power‐factor‐correction (PFC) voltage regulators. This paper begins with an application of duality transformation to conventional discontinuous‐conduction‐mode buck, buck‐boost and boost converters. The resulting dual converters operate in the discontinuous capacitor voltage mode. These new converters provide the same PFC property, but in the dual manner. It is proved that in the practical case of the input being a voltage source, the mandatory insertion of inductance between the voltage input and the ‘dual PFC converter’ does not affect the power‐factor‐correcting property. A new single‐stage PFC regulator is derived by taking the dual of a well‐known circuit based on a cascade of conventional boost and buck converters. Analytical design expressions are derived, illustrating the relation between current stress and component values. Experiments are performed to confirm the operation of the circuit and its power‐factor‐correcting capability. Copyright © 2003 John Wiley & Sons, Ltd.     

High‐efficiency transformerless buck–boost DC–DC converter

A novel high‐efficiency transformerless buck–boost DC–DC converter is proposed in this paper. The presented converter voltage gain is higher than that of the conventional boost, buck–boost, CUK, SEPIC and ZETA converters, and high voltage gain can be obtained with a suitable duty cycle. The voltage stress across the power switch is low. Hence, the low on‐state resistance of the power switch can be selected to decrease conduction loss of the switch and improve efficiency. The input current ripple in the presented converter is low. The principle of operation and the mathematical analyses of the proposed converter are explained. The validity of the presented converter is verified by the simulation results in PSCAD/EMTDC software and experimental results based on the prototype circuit with 250 W and 40 kHz. Copyright © 2017 John Wiley & Sons, Ltd.     

Single‐Inductor Dual‐Output DC–DC Converter Design Using RC Ripple Regulator Method

In this paper, we have proposed Single‐Inductor Dual‐Output (SIDO) buck–buck and boost–boost dc–dc converter using improved RC ripple regulator control. The proposed SIDO buck–buck converter has the characteristics of low‐ripple and high control frequency. RC ripple regulator control cannot be applied to SIDO boost–boost converter because RC ripple regulator undergoes self‐excited oscillation and two self‐excited oscillating controllers make the SIDO converter unstable. Thus we proposed the priority circuit for RC ripple regulator control. The proposed control circuit improves response characteristic and simplicity of the control circuit. Simulations are performed to verify the validity of the proposed SIDO converter. Simulation results indicate good performance of the proposed SIDO converter.     

Transient analysis of multi‐state dc–dc converters using system energy characteristics

The study of multi‐state dc–dc power conversion techniques is restricted by the complicated inner switching behaviors. This paper presents a general and unified transient analysis for various sorts of multi‐state dc–dc converters from a viewpoint of their system energy characteristics. With the applications to the boost converters, the proposed analytical method has indicated its advantages of high convenience and practicability to the multi‐state converters. The generalized concepts of system energy parameters of dc–dc converters are introduced and applied to the transient analysis. Consequently, the expressions of system model parameters of multi‐state dc–dc converters are deduced. The new 2nd order transfer functions are obtained to describe the large‐ and small‐signal mathematical models accurately. The model simulation and experimental results are provided to support the theoretical analysis. Copyright © 2007 John Wiley & Sons, Ltd.     

A new single‐phase high‐power‐factor converter with buck and buck–boost hybrid operation

In recent years, a wide variety of high‐power‐factor converter schemes have been proposed to solve the harmonic problem. The schemes are based on conventional boost, buck, or buck–boost topology, and their performance, such as output voltage control range in the boost and buck topology or efficiency in the buck–boost topology, is limited. To solve this, the authors propose a single‐phase high‐power‐factor converter with a new topology obtained from a combination of buck and buck–boost topology. The power stage performs the buck and buck–boost operations by a compact single‐stage converter circuit while the simple controller/modulator appropriately controls the alternation of the buck and buck–boost operation and maintains a high‐quality input current during both the buck and buck–boost operations. The proposed scheme results in a high‐performance rectifier with no limitation of output voltage control range and a high efficiency. In this paper, the principle and operation of the proposed converter scheme are described in detail and the theory is confirmed through experimental results obtained from 2‐kW prototype converter. © 2000 Scripta Technica, Electr Eng Jpn, 131(3): 91–100, 2000     

DC/DC变换器自适应模糊逻辑控制器设计

为DC/DC变换器设计了一种自适应模糊逻辑控制器（AFLC）。所提出的AFLC不需要专家系统提供决策参数和控制规则,而是使用模型数据文件来产生参数和规则,该模型数据文件包含输入输出对的整体概况。所提出的控制器使用8位微控制器来实现降压、升压和降压-升压变换器。     

A Multi-Functional Single-Stage Power Electronic Interface for Plug-In Electric Vehicles Application

This paper proposes a Zeta-derived non-isolated single-stage power electronic interface for on-board application of plug-in electric vehicles, which provides all modes (plug-in charging, propulsion, and regenerative braking) of vehicle operation. In addition, the proposed converter can charge the battery through universal input voltage range, i.e., 90–260 V due to buck/boost operations in plug-in charging mode. In propulsion and regenerative braking modes, the proposed converter operates as conventional boost and buck DC/DC converter, respectively. Compared to existing single-stage converters, the proposed converter has least components to those converters which have buck/boost operation in plug-in charging mode. A voltage/current stresses and loss analysis of the converter have been investigated for each mode of converter operation. Detailed simulation and experimental results are given to show the effectiveness of the proposed converter.     

一种可以建立软开关PWM变换器的系统方法

以结合开关理论为基础,提出了一种可以建立软开关PWM变换器的系统方法。应用这种方法,许多种无源和有源软开关PWM变换器家族中所派生出的变换器,如：Buck—Boost变换器、Cuk变换器、Sepic变换器和Zeta变换器都能够通过Buck变换器和Boost变换器这两种最基本的变换器得到,不仅对变换器家族可以进行更加深入的了解,还可以揭示出软开关变换器之间的内在联系。通过对结合开关理论的具体介绍,在对有源PWM软开关变换器中的零电压转换（ZVT）PWMDC／DC变换器的派生变换器电路拓扑的建立原理和得出过程重点阐述的同时。将有源软开关PWM变换器进一步分成了Buck和Boost家族两大类,并证明了所提出的这种建立软开关PWM变换器的方法的正确性和可行性。     

A White LED Driver Using a Buck–Boost Converter

For mobile backlighting applications, a white LED (WLED) driver using a buck–boost converter is proposed in this letter. Unlike conventional converters using boost converters, 2×/1.5× charge pumps, and so on, the proposed converter offers the negative stepped‐down voltage to drive the LED's cathode only when the input voltage is insufficient to drive a 1× transfer mode. Furthermore, unlike the LED backlight using charge pumps, the proposed converter can adjust the output voltage by controlling the duty factor of the clock pulse. Thus, the proposed converter can realize high power efficiency. The validity of the proposed converter is confirmed by simulations and experiments. © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

电压源换流器开关器件损耗建模

IGBT在电力电子装置中得到了大量应用,尤其是在高压大功率电压源换流器领域,而电压源换流器损耗分析一直是电力电子领域的一个研究热点。为了能对电压源换流器损耗进行精确分析,提出一种基于波形拟合理论的绝缘栅双极晶体管与二极管的损耗分析模型。建立的损耗模型充分考虑了电压源换流器不同开关里导通电流变化对于二极管反向恢复过程参数及损耗的影响,该模型还考虑了二极管与IGBT器件相互关系,器件电压、电流、结温变化对损耗的影响,特别计入了电流拖尾过程、电路杂散电感参数的影响。搭建了2.5kV输出Boost实验电路对该损耗模型进行验证,实验结果对比证明了该损耗模型的正确性和有效性。提出的损耗模型适用于电压源换流器型直流输电(voltage sourceconverter high voltage direct current,VSC-HVDC)、静止无功补偿器(static synchronous compensator,STATCON)、统一潮流控制器(unified power flow controller,UPFC)等高压大功率应用场合的电压源换流器损耗分析。     

一种开关变换器统一能量守恒平均模型

针对不同开关变换器模型与拓扑结构密切相关,转换困难的问题,依据能量守恒平均原理,建立连续模式下隔离和非隔离buck、boost、buck-boost变换器统一直流和小信号模型,并给出开环传递函数。将变换器中寄生参数及储能电感折算到与输出电容串联的支路中,在考虑寄生参数影响的同时,减小变换器结构上的差异。所建立的模型可以通过拓扑因数的选择,方便的实现不同变换器模型的转换,有利于各种变换器的比较研究。该模型同样适用于含有同步整流结构的情况。仿真分析表明,模型能够准确描述变换器的频域特性,验证了理论推导的有效性。     

Calculation of steady‐state solution of parallel‐connected buck converters with active current sharing and its parameter sensitivity

In this paper, the effect of active current‐sharing control on the steady‐state operation of parallel‐connected buck converters is investigated. The system under study consists of N voltage‐mode‐controlled buck converters connected in parallel. Three kinds of active current‐sharing schemes are considered, namely, master–slave scheme with automatic master, master–slave scheme with dedicated master, and democratic scheme. Using the principle of charge balance, the mechanism of the operating point drift arising from active current sharing is examined. A general formulation of the steady‐state solution under active current sharing is derived. Moreover, detailed parameter sensitivity analysis is performed to evaluate the effect of parameters' variation on the operating point. The results from sensitivity analysis can be used to categorize parameters for facilitating practical design. Computer simulations are presented to verify the analytical results. Copyright © 2010 John Wiley & Sons, Ltd.     

单开关DC/DC变换器的一种软开关实现策略

该文提出了一种适用于Buck、Boost、Buck-boost、Flyback等各种单开关DC／DC拓扑的软开关实现策略，即同步整流加上电感电流反向的策略。根据两个开关管实现软开关的条件不同，提出了强管和弱管的概念，给出了满足软开关条件的设计方法。一个24V输入，40V／2．5A输出，开关频率为200KHz的同步Boost变换器样机，进一步验证了上述软开关实现策略的正确性，其满载效率达到了96．9％。     

A new topology for nonisolated multiport zero voltage switching dc‐dc converter

In this paper, a new multiport zero voltage switching dc‐dc converter is proposed. Multiport dc‐dc converters are widely applicable in hybrid energy generating systems to provide substantial power to sensitive loads. The proposed topology can operate in 3 operational modes of boost, buck, and buck‐boost. Moreover, it has zero voltage switching operation for all switches and has the ability to eliminate the input current ripple; also, at low voltage side, the input sources can be extended. In addition, it has the ability of interfacing 3 different voltages only by using 3 switches. In this paper, the proposed topology is analyzed theoretically for all operating modes; besides, the voltage and current equations of all components are calculated. Furthermore, the required soft switching and zero input currents ripple conditions are analyzed. Finally, to demonstrate the accurate performance of the proposed converter, the Power System Computer Aided Design(PSCAD)/Electro Magnetic Transient Design and Control(EMTDC) simulation and experimental results are extracted and presented.     

A modified dual current mode control method with an adaptive current bandwidth

In this paper, a new adaptive dual current mode control method (ADCMC) is presented, being a result of the modification of existing dual current mode control (DCMC) by introducing an adaptive current bandwidth. The ADCMC offers several important advantages over DCMC, such as no peak‐to‐average error in the inductor current, better transient response of current loop, and improved line regulation. A detailed analysis of the proposed ADCMC is performed for three types of DC–DC power electronics converters: buck, boost, and non‐inverting buck–boost converter. The performances of the ADCMC are tested with simulations and experiments. The obtained results confirm the analysis and validity of the proposed ADCMC method. Copyright © 2015 John Wiley & Sons, Ltd.     

DSP based proportional integral sliding mode controller for photo-voltaic system

The buck–boost converter is controlled using different algorithms like voltage mode control, current mode control, V² control, enhanced V² control, Sliding Mode Control (SMC), and Proportional Integral (PI) control. In all these algorithms the steady state error is more. On combining PI control and sliding mode control the steady error can be minimized. In industry and commercial applications involving Photo-Voltaic (PV) systems, uses buck–boost converter. In this converter above control algorithms are implemented using hardware circuitry or microcontroller. In industry and commercial applications Digital Signal Processor (DSP) is used for automation purposes and the same DSP can be used to implement control algorithms so as to get maximum electrical energy from solar energy. The efficient utilization of resources such as DSP is achieved as we are using the same DSP for implementing control algorithm. In the proposed study, PI control method and sliding mode control methods are combined to obtain a Proportional Integral Sliding Mode Control (PISMC) and it is used to control the buck–boost converter which is used to drive the electrical loads from solar energy. The buck–boost converter is designed, simulated and implemented. The algorithms PI, SMC and PISMC are simulated in using MATLAB simulink and then implemented in DSP TMS 320 2808. In the proposed study PISMC, a stable and efficient output voltage is obtained in which the steady state error and maximum overshoot are minimum. The PISMC is better in terms of transient and steady state performances as validated by our experiments. The proposed study will work in real-time since DSP is used for implementing the control algorithms and found to be better in terms of speed and regulation. The proposed DSP based PISMC can also be used to control other types of DC–DC converters.     

Signal flow graph modeling of two-cell cascade buck converters

This paper presents signal flow graph nonlinear modeling of two-cell cascade buck converters. A systematic procedure for developing the unified flow graph model of the cascade converter is discussed. A simplified procedure is described that can be used to deduce large, small-signal and steady-state models from the unified signal flow graph of the converter. Converter performance expressions, and small-signal and steady-state transfer functions are derived. The large-signal model is developed and programmed into a TUTSIM simulator. Converter large-signal responses are obtained against supply and load disturbances. The validity of the proposed signal flow graph modeling of cascade converters is verified and comparisons are made via PSIM simulator results. A few experimental results are provided to verify the proposed method.     

Unified Pulse‐Width Modulation Scheme for Improved Digital‐Peak‐Voltage Control of Switching DC‐DC Converters

Contrast to conventional dependent double‐edge (DDE) pulse‐width modulation (PWM), independent double‐edge (IDE) PWM is investigated and applied to the control of switching dc‐dc converters, with improved digital‐peak‐voltage (IDPV) controlled buck converter in this paper. IDE modulation unifies all the PWM schemes reported up to now and is thus called as unified PWM. It is revealed that conventional trailing‐edge, leading‐edge, trailing‐triangle, and leading‐triangle modulations are special cases of IDE modulation. The control laws of IDPV controlled buck converter with IDE modulation are investigated and compared with those of IDPV with DDE modulation. Their stabilities and robustness are analyzed subsequently. Digital implementation of the unified PWM is also carried out. Steady‐state and transient performances of IDPV controlled buck converters with IDE modulation and DDE modulation are compared and verified by experimental results. It is concluded that steady‐state and transient performances of IDPV with IDE are better than those of IDPV with DDE modulation. Copyright © 2012 John Wiley & Sons, Ltd.     

Controller Design Using Ant Colony Algorithm for a Non-inverting Buck–Boost Chopper Based on a Detailed Average Model

In this article, the non-inverting buck–boost converter and its operation modes are scrutinized. The closed-loop stability of the converter in buck and boost modes is analyzed, and the necessity of using an appropriated controller is demonstrated. Then the application of an adapted ant colony optimization to design a feedback controller is proposed, and a controller based on its existing model is tuned. Simulation and experimental results obtained from the ant colony optimization designed controller are then compared with a controller designed with the classic method. Although the simulation and experimental results prove the efficiency of the proposed control approach, a significant difference between controller behavior in practice and simulation is obvious. Finding these differences, more detailed models, including all parasitic elements, in the buck and boost modes are derived. Applying the proposed model in controller design illustrates that the desired performance of the converter can be guaranteed with a simple proportional-integral (PI) controller. The suggested ant colony-based controller is again tuned based on the more detailed model, which improves the performance of the converter system even more. Furthermore, good agreement between analytical and experimental outputs validates the accuracy of the modeling and simulation.