一种改进的ZCT无桥功率因数校正电路设计

为了降低开关损耗,提高变换器的效率,提出了一种改进的零电流转化软开关无桥功率因数校正电路,实现了变换器主开关管和辅助开关管的零电流导通和零电流关断,有效地减小了导通损耗,提高了电路的效率。详细分析了电路的工作模态、工作条件和主开关管的导通损耗。仿真和实验结果表明,该功率因数校正电路实现了输入电流对输入电压的良好跟踪,功率因数高,谐波含量少,效率较传统的全桥功率因数校正电路有明显的提高。 关键词：全桥;零电流转换;无桥;功率因数校正     

Power factor correction converter using delay control

A low cost universal input voltage single-controller power factor correction converter for a 200 W power supply is proposed. It consists of the PFC part followed by a DC-DC converter as in a conventional two-stage scheme. However a single PWM controller is used as in a single-stage PFC scheme. The switch in the PFC part is synchronized with the switch in the DC-DC converter and has a fixed frequency. Employing an adaptive delay scheme, the PPC switch is controlled to limit the capacitor voltage within a desired range for optimum efficiency and to reduce input current harmonic distortion. The design procedures of the delay scheme, the feedback loop, and experimented results are presented to verify the performance     

A single-stage fast regulator with PFC based on an asymmetrical half-bridge topology

This work presents single-stage regulators with power-factor correction (PFC) based on an asymmetrical half-bridge topology. The proposed regulator is formed from a boost converter with two coupled inductors and an asymmetrical half-bridge converter with the synchronous switch technique, and it is controlled with pulsewidth modulation to achieve zero-voltage switching (ZVS). The boost converter is operated in discontinues conduction mode to achieve PFC. With the coupled inductors, input current ripple and power factor can be improved significantly. The proposed regulator has the features of constant-frequency operation, ZVS, and low voltage stress imposed on the active switches. Moreover, the regulator can achieve high power factor, high power density, high efficiency, low switching loss, and low component count, which makes its applications at medium-power levels feasible. Experimental results have verified the discussed features of the proposed regulator.     

Fast-scale instability of single-stage power-factor-correction power supplies

This paper describes the fast-scale bifurcation phenomena of a single-stage power-factor-correction (PFC) power supply which is a cost effective design for low-power applications. The circuit employs a cascade configuration of a boost converter and a forward converter, which share an active switch and operate in discontinuous conduction mode, to provide input PFC and tight output regulation. Main results are illustrated by "exact" circuit simulations as well as theoretical analysis based on the use of Jacobians. This work provides a convenient means of predicting stability boundaries which can facilitate the selection of practical parameter values for maintaining stable operation.     

A high-efficiency single-stage single-switch high-power-factorAC/DC converter with universal input

A single-stage single-switch power-factor-correction (PFC) AC/DC converter with universal input is presented in this paper. The PFC can be achieved based upon the charge-pump concept, and the PFC stage operates in the continuous current mode (CCM). The switch has less current and voltage stresses over a wide range of load variation so that a low-voltage rating device can be used. The presented converter features high power factor, high efficiency, and low cost. An 80-W prototype was implemented to show that it has 85% efficiency with low-voltage stress from 0.5% to 100% load variation over universal line input     

Novel zero-voltage-transition current-fed full-bridge PWM converterfor single-stage power factor correction

A novel zero-voltage-transition (ZVT) current-fed full-bridge pulsewidth modulation (PWM) power converter for single-stage power factor correction (PFC) is presented to improve the performance of the previously presented ZVT converter. A simple auxiliary circuit which includes only one active switch provides a zero-voltage-switching (ZVS) condition to all semiconductor devices (two active switches are required for the previous ZVT converter). This leads to reduced cost and a simplified control circuit compared to the previous ZVT converter. The ZVS is achieved for wide line and load ranges with minimum device voltage and current stresses. Operation principle, control strategy and features of the proposed power converter are presented and verified by the experimental results from a 1.5 kW 100 kHz laboratory prototype     

A Novel Single-Switch Single-Stage Electronic Ballast

A single-stage single-switch high- frequency electronic ballast topology is presented. The circuit topology is the integration of a buck power- factor-correction （PFC） converter and a class E resonant inverter with only one active power switch. The buck converter is operated in discontinuous conduction mode and at a fixed switching frequency, and constant duty cycle to achieve high power factor and it can be controlled easily. Detailed analysis of the operation and characteristics of the circuit is provided. Simulation results satisfy present standard requirements.     

A PFC voltage regulator with low input current distortion derived from a rectifierless topology

This paper presents an ac-dc converter topology for realization of power factor correction (PFC) voltage regulators for applications where the mains frequency is high and a low input current harmonic is required, e.g., in aircraft power systems. The proposed converter represents a minimal configuration consisting of two basic converters, which can be systematically derived from a previously proposed general synthesis procedure for rectifierless ac-dc converters. The proposed PFC converter has incorporated a control method which drastically reduces the circulating power and hence raises the efficiency to a level comparable to existing PFC converters. The proposed PFC converter can completely eliminate any crossover distortion, which can be significant for supply systems having a high mains frequency. In addition, the proposed converter allows bidirectional energy flow ensuring all inductors work in continuous conduction mode hence eliminating the distortion due to the abrupt change of dynamic response when the operating mode changes. Analysis and design of the power and control circuits will be given and discussed. An experimental system will be presented for verification purposes.     

An isolated bridgeless AC-DC PFC converter using a LC resonant voltage doubler rectifier

This paper proposed an isolated bridgeless AC–DC power factor correction (PFC) converter using a LC resonant voltage doubler rectifier. The proposed converter is based on isolated conventional single-ended primary inductance converter (SEPIC) PFC converter. The conduction loss of rectification is reduced than a conventional one because the proposed converter is designed to eliminate a full-bridge rectifier at an input stage. Moreover, for zero-current switching (ZCS) operation and low voltage stresses of output diodes, the secondary of the proposed converter is designed as voltage doubler with a LC resonant tank. Additionally, an input–output electrical isolation is provided for safety standard. In conclusion, high power factor is achieved and efficiency is improved. The operational principles, steady-state analysis and design equations of the proposed converter are described in detail. Experimental results from a 60 W prototype at a constant switching frequency 100 kHz are presented to verify the performance of the proposed converter.     

The zero Voltage switching (ZVS) critical conduction mode (CRM) buck Converter With tapped-inductor

The critical conduction mode (CRM) control has some disadvantages such as the increase of switching loss and conduction loss of the main switch at extreme high/low voltage conversion applications. In this paper, a CRM buck converter with tapped inductor is proposed to overcome these problems. In this converter, both the active switch and the diode have soft switching operation by the resonance between the switch parasitic capacitors and the filter inductor. Furthermore, the peak current of the main switch is reduced by tapped inductor operation, thus the conduction loss and switching loss levels of the main switch are lowered. Consequently, this tapped inductor scheme with CRM control alleviates the severe power stress and enhances device utilization. For the proposed converter evaluation, this paper provides the operation analysis and design procedures of the converter, and also presents the hardware verification for a 50-W prototype operating at maximum 70 kHz. Finally, a new topology family derived by combination of CRM operation with the basic tapped-inductor converter is included.     

新颖的含PFC的PWM ZVS AC-DC变换器

提出了一种新的具有功率因数补偿(PFC)功能的零电压开关(ZVS)AC-DC变换器,该变换器基于不连续导电模式(DCM)下的Boost环节实现PFC功能,但其具有ZVS机制,从而解决了DCM下因开关关断大的峰值电流引起的关断损耗高、EMI严重的问题,同时还消除了由于开关的寄生电容引起的开通损耗.该变换器可以采用通用控制芯片并工作在PWM模式.文中分析了提出变换器的工作原理,并给出了基本设计原则.模拟和实验结果证明了提出的电路是可行的.     

A novel one-stage forward-type power-factor-correction circuit

A novel power-factor-correction (PFC) circuit is proposed which is constructed with one stage by using a single forward converter. This PFC circuit has functions of high power factor and suppression of the output voltage ripple. The high power factor is accomplished by making the PFC circuit operate in the discontinuous conduction mode and the suppression of the output voltage ripple by using the exciting energy of the transformer in the forward converter     

基于GaN的图腾柱PFC电流过零点问题的研究

在连续导通模式下,图腾柱无桥拓扑结构功率因数校正器(PFC)的损耗非常大,导致拓扑结构的效率降低,在输入电压过零点处电流容易发生畸变。针对此问题,提出了一种改进的过零点控制方法。将输入电压过零时段划分为两个控制阶段,即高频桥臂主开关管完成软启动,采用双极控制方法有效校正输入电流,使其跟随输入电压。搭建一台1 kW实验样机,并利用DSP开发板进行实验验证。测试结果表明,当开关频率为100 kHz时,功率因数为0.99,PFC模块效率最大可达98.5%,总谐波失真在输出功率大于200 W时小于3%。     

A research to high-performance multi-level single-phase AC/DC power factor correct switching converter

This letter studies and analyzes the working features of main circuit of tri-level boost Power Factor Correct （PFC） converter and the advantages of tri-level switch converter in aspects of bearing high-voltage of power components, overall system loss and magnetic component selection based upon the single-level boost PFC switch converter. Besides, relying on the application of microprocessor in power converter technology and DSP （Digital Signal Processing） chip＇s strong calculating capacity, the letter presents the adoption of modified scheme of tri-level boost PFC converter under the control of predictive control algorithm. Moreover, the operating principle and control method are specified, the results of circuit test and analysis are provided and the advantages of predictive control technology-based multi-level boost PFC converter is verified.     

软开关隔离型升压DC-DC变换器设计与实现

为了满足升压型变换器低成本和大功率密度的需求,本文提出了一种软开关单极隔离型DC-DC变换器。该变换器电路包含一个无损耗缓冲器,通过漏电感固定住开关的电压峰值,从而实现开关的ZVS关断。在失谐状态下,使用Lr-Cr串联谐振电路来实现二极管的ZCS关断。由于磁化电流低,相较于传统的基于反激的变换器,变压器的容量更少。在输出功率250W和开关频率100kHz的条件下进行了实际测试,提出的变换器的最大测量效率为97.0%。     

一种新型低成本双极型组合转换器设计

为了降低直流微电网dc-dc转换器的成本,提出了一种新型低压直流双极型组合转换器。相比传统的转换器,该双极型组合转换器采用新的拓扑结构,结合了单端初级电感转换器（single ended Primary Inductance Converter,SEPIC）和Cuk转换器,并且共享开关节点。该拓扑结构的主要优势在于不需要严格控制各种开关的同步性,并且控制终端连接到了地面,从而大大简化了栅级驱动的设计,降低了实现成本。不同的负载条件下对提出的转换器进行了性能测试验证,实验结果表明提出的转换器十分适用于直流微电网,即使在失衡情况下也能完成电压调节能力,实测转换效率均保持在84%与87%之间。     

Buck–Boost-Type Unity Power Factor Rectifier With Extended Voltage Conversion Ratio

A buck-boost-type unity power factor rectifier is proposed in this paper. The main advantage of the proposed rectifier over the conventional buck-boost type is that it can perform input power factor correction (PFC) over a wider voltage conversion range. With a single switch, a fast well-regulated output voltage is achieved with a zero-current switch at turn-on. Moreover, the switch voltage stress is independent of converter load variation. The proposed converter is well suited for universal offline PFC applications for a low power range (<150 W ). The feasibility of the converter is confirmed with results obtained from a computer simulation and from an experimental prototype.     

An improved automotive power distribution system using nonlinearresonant switch converters

An improved automotive electrical system is proposed in which the generator is a high-efficiency AC machine connected to the battery by an AC-DC converter. The electrical loads are isolated from the battery by a DC-DC converter. This will allow gradual conversion to higher battery voltage, regulation of DC distribution voltage, and multiple distribution voltage levels. In the low-voltage, high-current, high-temperature environment of the automobile, in addition to packaging and thermal management, a major problem is the switching loss caused by leakage, package, and other parasitic inductances. The nonlinear resonant switch can remove this source of loss, achieving zero current switching without sacrificing conduction loss or MOSFET switch utilization. For the nonlinear resonant switch in a 1.5 kW load converter application, the upper limit is approximately 20 nH. Hence, device interconnections have low inductance, and MOSFET package inductances are taken into account. A low-voltage, high-current nonlinear resonant switch converter operating at 700 kHz an producing 600 W is described     

Design and analysis of a novel zero-voltage-transition interleaved boost converter for renewable power applications

High-efficiency stepping up operation is an important feature of the converters used in renewable power applications due to the low voltage level of photo-voltaic arrays and fuel cells. Decreasing the switching losses of the converters is an effective solution for increasing the converter efficiency, especially in high-power applications. This article presents a novel zero-voltage-transition (ZVT) interleaved dc–dc boost converter that can be used in renewable power sources to reduce switching losses. The auxiliary circuit used in the proposed converter is composed of only one auxiliary switch and a minimum number of passive components without an important increase in the cost and complexity. The main advantage of the proposed converter is that it not only provides ZVT in the boost switches but also provides soft switching in the auxiliary switch. Another advantage of the proposed topology is that the semiconductor devices used in the converter do not have any additional voltage or current stresses. Also, it has a simple structure, low cost and ease of control. In this article, a detailed steady-state analysis of the proposed converter is presented. The theoretical analysis is verified via simulation and experimental studies which are in very good agreement.     

基于单周期控制的Boost—PFC变换器的研究

单周期控制技术(One-Cycle-Control,简称OCC)是一种新型非线性大信号PWM控制技术,是一种不需要乘法器的新颖功率因数校正(Power Factor Correction,简称PFC)控制方法,它将非线性开关变为线性开关。当输入电压发生扰动或负载快速变化情况时,仅在一个周期内就可实现控制目标,本文论述了单周期控制技术的基本原理,应用单周期控制芯片IR1150制作了一台原理样机,并进行了实验论证。实验结果证明,单周期控制BoostPFC变换器具有功率因数高、效率高,结构简单,工作稳定等优点。