开关电源功率因数的校正技术

从不同角度来说,功率因数校正(PFC)技术有着不同分类方法,若从电网供电的的方式来看,就可分为单相PFC电路与三相PFC电路,若从校正机理来看,又可分为无源功率因数校正(PPFC)与有源功率因数校正(APFC)两种。故文章从开关电源的PFC原理分析入手,对单相与三相PFC技术作一简要分析。     

三相四线制无功与谐波全补偿的并联有源电力滤波器的研究

简要分析了并联有源电力滤波器的工作原理,选取含有裂相电容的三桥臂电压源型逆变器作为系统主电路,输出电流采用动态滞环控制。针对三相四线系统,且考虑到电网电压畸变和不对称的情况,给出了一种基于瞬时功率理论实现无功功率和谐波全补偿的控制策略,并使用Matlab对系统进行了仿真。     

三相四线制无功与谐波全补偿的并联有源电力滤波器的研究

简要分析了并联有源电力滤波器的工作原理，选取含有裂相电容的三桥臂电压源型逆变器作为系统主电路，输出电流采用动态滞环控制。针对三相四线系统，且考虑到电网电压畸变和不对称的情况，给出了一种基于瞬时功率理论实现无功功率和谐波全补偿的控制策略，并使用Matlab对系统进行了仿真。     

正弦波脉宽调制交流稳压电源

在小功率油机发电机供电,逆变电源供电和电网供电频率波动大的用电场合,要求有一个频率恒定的纯正弦波输出稳压电源,以保证用电单元稳定可靠地工作。当要求交流电机转速稳定和可调时,需要有一个输出频率自动或人工控制的纯正弦波输出单相或三相稳压电源。在很多场合还需要三相转换为单相电源,或单相转换成三相电源。采用正弦波脉宽调制技术能方便地设计出上述电源。实现正弦脉宽调制(SPWM)有多种方法。我们在设计中应用了D类音频功率放大器的原理。图1给出了D类音频功率放大器的原理方框图。图中,正     

三相三开关部分有源功率因数校正电路的研究

三相交流电源供电的较大功率变频空调日益得到广泛应用,带来了三相整流器的功率校F问题。在简要分析三相单开关部分有源PFC的基础上,根据三相三线制、三相四线制供电方式的不同,提出了两种结合有源PFC技术和无源PFC技术的Buck型混合三相有源部分PFC方案,在对其工作原理进行简要分析和仿真分析的基础上,进行了实验研究,所得结果验证了所提出的三相部分PFC具有电压与电流应力小、效率高、功率因数高、直流平均电压较高的特点,各种负载下交流输入侧的各次谐波电流均满足IEC61000-3-2标准,中等负载以上时输入功率因数高达0.98。     

准Z源在三相AC/AC变换器中的应用研究

对于传统三相斩控式交流调压器的缺点和不足,提出了 3种新型三相准Z源AC/AC变换器电路拓扑,研究并分析了 其中一种电路的基本结构和工作原理,运用伏秒平衡原理计算出了占空比和输出电压的关系,利用MATLAB/Simulink仿真环境对新型电路拓扑进行仿真,并采用脉冲宽度调制方法(PWM)来控制占空比来调节输出电压。最后根据仿真来搭建实验电路,得出的实验结果验证了新型三相准Z源AC/AC变换器电路的可靠性和可行性。     

矩阵整流器输入与输出滤波器特性的研究

矩阵整流器是一种真正的降压型四象限AC-DC变换器,可以用在各种三相电压供电的直流电源领域。鉴于矩阵整流器采用波形高频合成原理实现输入电压-输出电压的变换和输出电流-输入电流的变换,并非纯硅变换器,输入LC滤波器与输出LC滤波器的设计至关重要,并决定着整流器系统的功能、性能和可靠性。在理论分析矩阵整流器与电流源PWM整流器具有共同变换本质的基础上,采用电路DQ转换方法,建立输入LC滤波器-矩阵整流器-输出LC滤波器系统的DC等效电路,重点分析了DC特性高低对滤波器参数设计要求,进而给出设计原则和参数选择公式,并进行实验验证。     

采用功率因数校正(PFC)技术设计电源

如要利用功率因数校正(FPC)技术来开发电源,必须先了解PFC的含义,以及这类设计所牵涉的规范要求,例如不同类型电源要求的PFC最小输出功率。PFC的基本目的在于使电流和电压波形相同且相位一致。如果电压和电流的波形和相位不一致,功率因数(PF)就小于1(见图1),相反的结果则接近等于1(见图2)。在大多数情况下,含功率因数校正电路的PF值在0.95至0.98之间,而没有采用PFC电源的PF则为0.6左右。举例说,在三相交流供电系统中,如果电压和电流的波形相位不一致,非正弦电流会在中线中产生高次大电流谐波(约为工频的三倍),使供电公司不得不采用…     

基于M30624FGAFP控制的三相逆变电源的研制

本文介绍了由16位单片机M30624FGAFP控制的三相逆变电源的原理,它可在输入电压低、谐波含量大的情况下,仍能输出高质量的稳定可靠的三相正弦电压,保证系统运行的可靠性与连续性。     

利用谐振电抗器实现单相无源功率因数校正

本文详细描述了一种新型基于谐振电抗器原理的单相无源功率因数校正（PFC）技术，可以适用于各种变频家用电器。在对其工作原理进行较为详细理论分析的基础上，进行了完整的仿真分析和实验研究，指出了这种无源PFC的最佳设计目标参数选择方法，给出了有关仿真与实验的波形和数据，并进行了分析比较。结果表明，这种无源PFC方案的输入谐波电流校正效果良好，直流回路电压利用率最高，而且具有散热处理，安装方便与价格低廉等特点，可以作为较大功率的单相C-DC变换器为后级逆变器-压缩机系统供电。     

New three-port DC-AC inverter outputting a single-phase and a set of three-phase AC voltages

A conventional DC-AC inverter can only output either a single-phase AC voltage or a set of three-phase AC voltages. A new three-port DC-AC inverter which can simultaneously output a single-phase AC voltage and a set of three-phase AC voltages is proposed in this paper. This three-port DC-AC inverter is based on the three-port T-type multi-level power converter which is composed of three T-type power electronic legs, a decoupling transformer set, a filter inductor set, a single-phase filter capacitor, and a three-phase filter capacitor set. The DC port of the proposed power converter is connected to a DC power source to act as the input port, and the single-phase AC port and the three-phase AC port serve as two output ports to supply power to the single-phase load and the three-phase load, respectively. The zero-sequence transformer is used to decouple the single-phase and three-phase AC components, which are generated by the three T-type power electronic legs. The operation principle of this three-port DC-AC inverter is analyzed, and a hardware prototype is established to verify the performance of the proposed three-port DC-AC inverter. The experimental results are as expected.     

单周期控制三相VIENNA整流器

电网谐波污染已经引起世界各国的高度重视,功率因数校正（PFC）是治理谐波的一种有效方法。文章对基于单周期控制的三相VIENNA整流器进行了研究,推导了单周期控制三相VIENNA整流器的控制规律,与其它控制方案相比不需要乘法器,不需对电源电压进行检测,控制逻辑比较简单并且以恒定开关频率工作,能够实现单位功率因数校正和低电流畸变。仿真结果验证了理论分析的正确性。     

A digitally controlled switch mode power supply based on matrix converter

High power telecommunication power supply systems consist of a three-phase switch mode rectifier followed by a dc/dc converter to supply loads at -48 V dc. These rectifiers draw significant harmonic currents from the utility, resulting in poor input power factor with high total harmonic distortion (THD). In this paper, a digitally controlled three-phase switch mode power supply based on a matrix converter is proposed for telecommunication applications. In the proposed approach, the matrix converter directly converts the low frequency (50/60Hz, three-phase) input to a high frequency (10/20kHz, one-phase) ac output without a dc-link. The output of the matrix converter is then processed via a high frequency isolation transformer to produce -48V dc. Digital control of the system ensures that the output voltage is regulated and the input currents are of high quality under varying load conditions. Due to the absence of dc-link electrolytic capacitors, power density of the proposed rectifier is expected to be higher. Analysis, design example and experimental results are presented from a three-phase 208-V, 1.5-kW laboratory prototype converter.     

An improved control algorithm of shunt active filter for voltageregulation, harmonic elimination, power-factor correction, and balancingof nonlinear loads

This paper deals with an implementation of a new control algorithm for a three-phase shunt active filter to regulate load terminal voltage, eliminate harmonics, correct supply power-factor, and balance the nonlinear unbalanced loads. A three-phase insulated gate bipolar transistor (IGBT) based current controlled voltage source inverter (CC-VSI) with a DC bus capacitor is used as an active filter (AF). The control algorithm of the AF uses two closed loop PI controllers. The DC bus voltage of the AF and three-phase supply voltages are used as feedback signals in the PI controllers. The control algorithm of the AF provides three-phase reference supply currents. A carrier wave pulse width modulation (PWM) current controller is employed over the reference and sensed supply currents to generate gating pulses of IGBTs of the AF. Test results are presented and discussed to demonstrate the voltage regulation, harmonic elimination, power-factor correction and load balancing capabilities of the AF system     

应用并联型有源滤波器抑制雷达电源的谐波

针对雷达电源工作时产生的谐波电流对电网污染严重的情况，提出了采用并联型有源电力滤波器来抑制雷达电源工作时产生的谐波电流。首先分析了并联型有源电力滤波器的工作原理和基于傅里叶变换理论的谐波电流检测算法；然后介绍了采用二重化方案设计的主电路以及相应控制电路，最后给出了实验结果。实验证明，无论雷达电源工作在稳态还是脉动方式，并联型有源电力滤波器能有效抑制其工作时产生的谐波。     

A new hybrid filter to dampen resonances and compensate harmoniccurrents in industrial power systems with power factor correctionequipment

A new hybrid power filter is presented for three phase industrial power systems which include passive power factor correction equipment (PFC). The hybrid filter damps resonances occurring between line impedances and the PFC. In addition, the hybrid filter topology can be used to compensate harmonic currents. The capacitors of the PFC, which generally cause resonant problems in harmonic distorted networks, can be used for passive filtering by connecting a transformer with a low magnetizing inductance in series hence creating a single harmonic trap. The primary side of the transformer is connected to a low VA-rated three-phase current controlled inverter which builds the active part of the hybrid topology. Simulation results and experimental results are presented verifying the damping and harmonic compensation performance of the proposed topology     

一种输出功率稳定及功率因数改善的激光电源

叙述了输出功率稳定、功率因数改善的激光电源的设计原理及电路构成。该电源输出功率可以不随电网电压变化而基本保持一定,从而可使激光输出能量稳定度大大提高。由于采用了功率因数改善的电路,该电源有效地抑制了谐波噪声,减少了电力设备的输入电流容量,拓宽了电源输入电压的范围。     

Analysis of the Instantaneous Power Flow for Three-Phase PWM Boost Rectifier Under Unbalanced Supply Voltage Conditions

This paper proposes the analysis of the instantaneous power flow of three-phase pulse-width modulation (PWM) boost rectifier under unbalanced supply voltage conditions. An analytical expression for the instantaneous output power has been derived, which provides the link between the output dc link voltage and the instantaneous output power. A direct relationship between the dc link voltage ripples and the second harmonic component in the instantaneous output power has been established. Based on the input and output instantaneous power analytical expressions provided, the presence of the odd order harmonic components in the ac line currents can be explained. A simple cascaded PI control scheme has been developed for the dc output voltage control. The controller ensures that the dc link voltage is maintained constant and the supply side power factor is kept close to unity under the unbalanced supply voltage operating conditions. Simulation and experimental test results are provided on a 1.6-kVA laboratory-based PWM rectifier to validate the proposed analysis and control scheme.      

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.