A Unity Power Factor Correction Preregulator With Fast Dynamic Response Based on a Low-Cost Microcontroller

Low cost passive power factor correction (PFC) and single-stage PFC converters cannot draw a sinusoidal input current and are only suitable solutions to supply low power levels. PFC preregulators based on the use of a multiplier solve such drawbacks, but a second stage dc-dc converter is needed to obtain fast output voltage dynamics. The output voltage response of PFC preregulators can be improved by increasing the corner frequency of the output voltage feedback loop. The main drawback to obtaining a faster converter output response is the distortion of the input current. This paper describes a simple control strategy to obtain a sinusoidal input current. Based on the static analysis of output voltage ripple, a modified sinusoidal reference is created using a low cost microcontroller in order to obtain an input sinusoidal current. This reference replaces the traditional rectified sinusoidal input voltage reference in PFC preregulators with multiplier control. Using this circuitry, PFC preregulator topologies with galvanic isolation are suitable solutions to design a power supply with fast output voltage response (10 or 8.33 ms) and low line current distortion. Finally, theoretical and simulated results are validated using a 500 W prototype.     

A Novel AC UPS With High Power Factor and Fast Dynamic Response

This paper presents a novel ac uninterruptible-power-system (UPS) scheme with high power factor, which offers excellent characteristics such as sinusoidal input current, sinusoidal output voltage, fast regulation of the ac mains, galvanic isolation, and fast transient response. The proposed converter includes the offline–online concept, which avoids the continuous charging and discharging of the battery as it occurs in a typical online UPS. Analysis and design considerations, as well as simulation and experimental results, are given in this paper.      

High Power Factor Operation of a Three-Phase Rectifier for an Adjustable-Speed Drive

This paper presents a novel approach to improve the power factor (PF) and reduce the harmonics generated by an adjustable-speed drive (ASD). A high-frequency (HF) current injection technique is used to improve the PF and harmonic performance. The HF current at the same switching frequency (33 kHz) is injected into the input of a front-end rectifier from the output of an HF inverter. The main feature of the circuit is that it does not require any additional active devices for current injection. The inverter driving the induction motor is operated using a sinusoidal pulsewidth-modulation technique. The circuit simulation and experimental prototype results are presented for 67-hp (50 kW) and 3-hp three-phase induction motors, respectively.     

一种快速瞬态响应Buck变换器设计

提出了一种基于锁相环锁频锁相ACOT控制模式的Buck变换器。该变换器具有快速瞬态响应的特点。分析发现,在负载阶跃时,传统ACOT控制模式Buck变换器受到最小关断时间和锁相环速度的限制,不能完全发挥其瞬态响应快的优势。设计了一种根据设定的开关频率可自适应调节环路参数的Buck变换器,它在较宽的开关频率下具有快速的瞬态响应特性。采用0.18 μm BCD工艺对提出的Buck变换器进行仿真验证。结果表明,负载电流从1 A跳变到5 A时,输出电压下冲恢复时间减小为1.68 μs。     

Analysis and Implementation of a Hybrid High-Power-Factor Three-Phase Unidirectional Rectifier

This paper describes the conception and analysis of a unidirectional hybrid three-phase rectifier suitable for medium- and high-power applications. The rectifier is composed of a single-switch diode bridge boost-type rectifier in parallel with a pulsewidth modulation (PWM) three-phase unidirectional boost rectifier. The objective is to obtain a structure capable of providing sinusoidal input currents with low harmonic distortion and dc output voltage regulation. The diode rectifier operates at low frequency and has a higher output power rating. Therefore, the PWM unidirectional rectifier is designed to operate with a small power rating and at a high switching frequency. The total harmonic distortion of the proposed structure varies between 0% and 32%, depending only on the amount of power processed by the PWM three-phase unidirectional rectifier. The rectifier topology conception, principle of operation, control scheme, and simulation and experimental results of a 20-kW laboratory prototype are also presented in this paper.     

Analysis and Design of a Novel Three-Phase AC–DC Buck-Boost Converter

This paper proposes a novel three-phase ac-dc buck-boost converter. The proposed converter uses four active switches, which are driven by only one control signal. This converter is operated in discontinuous conduction mode (DCM) by using the pulsewidth modulation (PWM) technique, and the control scheme very easily and simply achieves purely sinusoidal input current, high power factor, low total harmonic distortion of the input current and step-up/down output voltage. Also, the proposed converter provides a constant average current to the output capacitor and load in each switching period. Thus, the ripple component of sixth times line frequency will not appear in the output voltage. Therefore, a smaller output capacitor can be used in the proposed converter. Moreover, the steady-state analysis of voltage gain and boundary operating condition are presented. Also, the selections of inductor, output capacitor and input filter are depicted. Finally, a prototype circuit with simple control logic is implemented to illustrate the theoretical analysis.     

高功率因数整流器系统设计与仿真研究

在三相VSR主电路结构的基础上,分析PWM整流器在dq坐标系下的数学模型,并在此模型上建立了电压调节器解耦dq轴电流的简化模型结构,给出了工程上的PI调节器参数的设计方法。通过MATLAB仿真,验证了在模型可运行在单位功率因数下,并可实现能量回馈,且对负载的突变有较强的适应性。最后,把模糊控制应用到电压环中,使直流母线电压在动态响应过程中的超调量控制在一定的范围内,通过MATLAB仿真,验证了其可行性。     

直接电流控制的三相桥式PWM整流电路的设计与分析

文章对直接电流控制的PWM整流电路开展研究,主要内容如下：（1）设计BOOST型三相桥式PWM整流器的主电路。（2）设计基于直接电流控制的PWM整流电路的控制系统。（3）建立直接电流控制系统Simulink仿真模型,进行仿真分析。仿真结果证明直接电流控制方案使得PWM整流器功率因数接近于1,流入电网的电流基本接近正弦波,对电网的谐波污染小。     

A Comprehensive Analysis of Hybrid Phase-Modulated Converter With Current-Doubler Rectifier and Comparison With Its Center-Tapped Counterpart

A hybrid phase-modulated converter (HPMC) is a recent innovation in the family of soft-switching converters. It is a promising solution to most soft-switching issues. The principal bottleneck in achieving higher efficiency with this topology is the secondary side loss-mainly the losses in the transformer and the rectifier. For low-voltage high-current power supplies, the current-doubler rectification of HPMC addresses both the transformer conduction losses and the rectifier losses. The presence of an additional path for quiescent current in this scheme gives rise to a third mode of operation. There is also the possibility of magnetic integration of all the magnetic components into one, which can cause substantial reduction in magnetic requirements. These facts make the analysis of current doubler important. In this paper, all the operating modes are identified and corresponding equations and equivalent circuits that aid in filter and control design are derived. The zero-voltage-switching (ZVS) characteristics, filter requirement, small-signal transfer characteristics, device ratings, and magnetics size requirement are considered to compare this configuration with its center-tapped counterpart. The current-doubler scheme is found to have superior soft-switching characteristics in that it can achieve ZVS at lighter loads with a much lower peak magnetizing current in the transformer and leakage inductance. Also, a judicious choice of output current ripple can give an overall reduced magnetics requirement. The analyses are verified by simulation and hardware implementation. HPMC is found to be most advantageous for applications with input voltages essentially constant, but the output voltage widely varying, for example in battery chargers and converters with power factor correction front end     

一种加入动态补偿电路的快速响应LDO设计

当输入电压或者负载电流变化时低压差线性稳压器(LDO)系统稳定性是其研究热点和设计难点.针对这一问题,设计了一款加入动态补偿电路的快速响应LDO,这种新颖的LDO结构能有效改善在不同负载电流或者输入电压下系统的稳定性能.其适用电压范围为4.5～16.0V,输出电压5.0V,具有低功耗、带宽宽等特性.使用Hspice软件对设计的LDO进行了仿真验证,在典型工艺角下,负载电流经100 mA/μs突变时,输出电压突变量最大为105 mV,响应恢复时间平均约2.1 μs.环路特性仿真结果表明,该LDO带宽为4.9 MHz,3 dB带宽为3.5MHz,相位裕度为约76°,且片内补偿电容仅0.3 pF.     

一种高速大功率半导体脉冲激光电源的设计与仿真

主要分析了影响电容充放电类型高速大功率脉冲电源性能的主要因素 ,并运用SPICE对其特性进行仿真 ,介绍了一种基于高速大功率MOSFET管实现高速大功率半导体脉冲激光电源的方法     

Analysis and Design of a Photovoltaic System DC Connected to the Utility With a Power Factor Corrector

This paper presents a photovoltaic (PV) system parallel connected to an electric power grid with a power factor corrector (PFC) for supplying the DC loads. The operation principles and design considerations for the presented PV system are analyzed and discussed. The balanced distribution of the power flows between the utility and the PV panels is achieved automatically by regulating the output DC voltage of the PFC. Experimental results are shown to verify the feasibility of the proposed topology, which can effectively transfer the tracked maximum power from the PV system to the DC load, while the unity power factor is obtained at the utility side.     

IPM智能功率模块的设计与分析

引言 IPM智能功率模块是先进的混合集成功率器件,由高速、低功耗的IGBT芯片和优化的门极驱动以及保护电路构成.由于采用了能连续监测功率器件电流的、有电流传感功能的IGBT芯片,从而可实现高效的过流保护和短路保护.由于IPM智能功率模块集成了过热和欠压锁定保护电路,因而系统的可靠性得到了进一步提高.     

A Three-Level Resonant Single-Stage Power Factor Correction Converter: Analysis, Design, and Implementation

This paper presents a new single-stage power factor correction ac/dc converter based on a three-level half-bridge resonant converter topology. The proposed circuit integrates the operation of the boost power factor preregulator and the three-level resonant dc/dc converter. A variable-frequency asymmetrical pulsewidth modulation controller is proposed for this converter. This control technique is based on two integrated control loops: the output voltage is regulated by controlling the switching frequency of the resonant converter, whereas the dc-bus voltage and input current are regulated by means of duty cycle control of the boost part of the converter. This provides a regulated output voltage and a nearly constant dc-bus voltage regardless of the loading condition; this, in turn, allows using smaller switches and consequently having a lower on resistance helping to reduce conduction losses. Zero-voltage switching is also achieved for a wide range of loading and input voltage. The resulting circuit, therefore, has high conversion efficiency making it suitable for high-power wide-input-voltage-range applications. The effectiveness of this method is verified on a 2.3-kW 48-V converter with input voltage (90–265 Vrms).      

Design of a 1-MHz LLC Resonant Converter Based on a DSP-Driven SOI Half-Bridge Power MOS Module

In this paper, the design of a 1-MHz LLC resonant converter prototype is presented. Aiming to provide an integrated solution of the resonant converter, a half-bridge (HB) power metal oxide semiconductor (MOS) module employing silicon-on-insulator technology has been designed. Such a technology, which is suitable for high-voltage and high-frequency applications, allows enabling HB power MOSFET modules operating up to 3MHz with a rated voltage of 400V. The power device integrates the driving stages of the high-side and low-side switch along with a latch circuit used to implement over-voltage/over-current protection. The module has been designed to be driven by a digital signal processor device, which has been adopted to perform frequency modulation of the resonant converter. By this way, output voltage regulation against variations from light- to full-loaded conditions has been achieved. The issues related to the transformer design of the LLC resonant converter are discussed, too. Owing to the high switching frequency experienced by the converter, 3F4 ferrite cores have been selected for their low magnetic power losses between 0.5 and 3 MHz and core temperatures up to 120degC. The resonant converter has been designed to operate in an input voltage range of 300-400V with an output voltage of 12V and a maximum output power of 120W. Within these design specifications, a performance analysis of the LLC converter has been conducted, comparing the results obtained at the switching frequencies of 500kHz and 1MHz. A suitable model of the LLC resonant converter has been developed to aid the prototype design.     

Analysis and Design of a High-Frequency Resonant Converter Using LCC-Type Commutation

The modeling, analysis, and design of a high-frequency resonant converter using an LCC-type commutation circuit is presented. Constant-current model and state-space approaches are used for the analysis. Closed-form solutions are derived for the inverter under steady-state conditions. Experimental results obtained from a prototype converter under different loading conditions are compared with the theory.     

三相全控整流感性负载谐波与功率因数的仿真

通过对Matlab的Simulink建立三相全控整流的仿真模型进行动态仿真.阻感负载整流电路作为电力电子装置输入端电路之一,是电力系统中的主要谐波源.从工程实际出发,忽略换相过程和直流侧电流脉动,对阻感负载三相桥式全控整流电路的功率因数和谐波情况进行动态仿真.仿真结果证实了模型的正确性,可以看出仿真使复杂的计算变得简单...     

Analysis and Design for a Novel Single-Stage High Power Factor Correction Diagonal Half-Bridge Forward AC–DC Converter

By means of components placement, the buck-boost and diagonal half-bridge forward converters are combined to create a novel single-stage high power factor correction (HPFC) diagonal half-bridge forward converter. When both the PFC cell and dc–dc cell operate in DCM, the proposed converter can achieve HPFC and lower voltage stress of the bulk capacitor. The circuit analysis of the proposed converter operating in$ DCM+ DCM$mode is presented. In order to design controllers for the output voltage regulation, the ac small-signal model of the proposed converter is derived by the averaging method. Based on the derived model, the proportional integral (PI) controller and minor-loop controller are then designed. The simulation and experimental results show that the proposed converter with the minor-loop controller has faster output voltage regulation than that with the PI controller despite the variations of line voltage and load. Finally, a 100-W prototype of the proposed ac–dc converter is implemented and the theoretical result is experimentally verified.     

SiC宽带功率放大器模块设计分析

功率放大器是射频前端中的关键部件,宽带是目前功率放大器的主要发展趋势。基于碳化硅(SiC)宽禁带功率器件,利用ADS仿真软件,依据宽带功率放大器的各项指标进行电路的设计、优化和仿真,制作了500~2 000 MHz波段宽带功率放大器,并对放大器进行了性能测试和环境实验。测试结果表明利用该方法设计宽带功率放大器是可行的,SiC宽禁带功率器件具有较宽的工作带宽。     

Design and Application for PV Generation System Using a Soft-Switching Boost Converter With SARC

In order to improve the efficiency of energy conversion for a photovoltaic (PV) system, a soft-switching boost converter using a simple auxiliary resonant circuit, which is composed of an auxiliary switch, a diode, a resonant inductor, and a resonant capacitor, is adopted in this paper. The conventional boost converter decreases the efficiency because of hard switching, which generates losses when the switches are turned on/off. During this interval, all switches in the adopted circuit perform zero-current switching by the resonant inductor at turn-on, and zero-voltage switching by the resonant capacitor at turn-off. This switching pattern can reduce the switching losses, voltage and current stress of the switching device. Moreover, it is very easy to control. In this paper, we have analyzed the operational principles of the adopted soft-switching boost converter, and it is designed for PV generation system. Simulation and experimental results are presented to confirm the theoretical analysis.