有源高功率因数电子镇流器

为了提高电子整流器的功率因数,讨论了高性能电子镇流器系统必须具备的电路结构和功率因数校正电路(PFC)的基本原理。介绍了一种以L6561为功率因数校正控制器的有源高功率因数电子镇流器,说明该镇流器的电路组成及L6561的主要特点,并给出详细的电路原理图及主要元器件的选型。     

单相PWM整流器能量双向传输的实现技术

本文论证了高功率因数电能转换和负载电能回馈电网的实现是电力节能的关键问题.在对电压型单相PWM整流器的拓扑结构以及其工作原理分析的基础上,提出了相应的控制方法,并分别对主电路参数和PI调节器参数进行了选择和设计,重点对IGBT的驱动电路进行了详细的设计.基于Matlab计算机仿真软件,文中对整个单相PWM整流器控制系统进行了建模和仿真,结果表明,PWM整流器控制系统能很好地实现高功率因数电能转换和电能的双向传输.     

单相可逆PWM整流器能量双向传输的研究

高功率因数电能交换和负载电能回馈电网的实现是电力节能的关键问题.在对电压型单相PWM(Pulse-width Modulation)整流器的拓扑结构以及其工作原理的分析基础上,提出了相应的控制方法并分别对主电路参数和PI调节器参数进行了选择和设计.基于Matlab计算机仿真软件对整个单相PWM整流器控制系统进行了建模和仿真,结果表明PWM整流器控制系统能很好实现高功率因数电能变换和电能的双向流动.     

一种混合整流技术在航空AC/DC变换器中的应用

本文研究了一种新的高功率因数、低电流谐波整流器,它适用于航空115VAC到270VDC的AC/DC变换器。该整流器采用了PWM整流与二极管整流并联结构,其中二极管整流承担绝大多数功率输出,通过适当控制PWM整流器得到低谐波、高功率因数的交流侧电流。该论文对该整流器的模型进行了分析,提出采用基于内模原理和重复控制的控制方法,并且对嵌入内模控制的重复控制器进行了稳定性分析与设计,仿真结果证明该控制器使这种半控型整流系统取得理想的性能。     

基于SVPWM的航空高功率因数整流器设计

为了消除电网谐波污染、提高整流器的功率因数,对具有输出电压稳定、能够获得单位功率因数特点的三相电压型PWM整流器的控制策略进行了研究.介绍了空间矢量PWM(SVPWM)控制技术,并将该技术应用于航空整流器的设计;完成数字控制电路中网侧电压调理电路和直流侧输出电压调理电路以及相关软件的设计.实验结果表明,采用SVPWM电流控制技术能够使网侧电压与电流同相位,实现单位功率因数整流.     

三相整流器功率因数校正电路的现状与发展

对近年来几种典型三相整流器功率因数校正电路作了简要的比较和归纳总结，在此基础上分析了三相整流器功率因数校正电路今后的发展动向。     

软开关APFC倍频感应加热电源的研究

针对倍频感应加热电源整流器的非线性特性引起网侧电流畸变,功率因数低等问题,采用一种新型的软开关Boost电路取代传统LC滤波环节进行功率因数校正。整个电源系统采用DSP＋CPLD实现了CCM模式下的平均电流PFC控制和倍频逆变模块的分时一移相控制策略。仿真与试验结果实现了输入侧单位功率因数,升压电路的开关管在高频开关状态下实现ZCS开启与ZVS关断,开关损耗大大降低。     

IGBT整流器功率因数控制方法及CT损坏对整流器的影响

IGBT整流器通过采用功率因数以及PWM矢量控制技术,使网侧输入功率因数达到1.0,既保证了有功功率传输的最大化,又可减少电网侧无功补偿的设备。高功率因数控制的IGBT整流器完全满足了现场实际使用要求。此外,还阐述了CT异常对整流器的影响。     

21kW18脉冲自耦型变压整流器的分析与实现

结合机载电子设备低谐波污染的需求,针对机载变频器设备研制三相输入、高功率因数、高可靠的变压整流器.考虑到谐波电流和体积重量的要求,选取18脉冲不对称式自耦变压整流器方案.详细分析了电路的工作原理,忽略直流侧的电流脉动,推导了电路的输出电压和输入电流特性,给出了自耦变压器的设计依据.最后完成了21 kW18脉冲变压整流器的电路参数设计和硬件实验.额定条件下,整流器功率因数为0.996,总谐波电流含量为7.6%,变换效率为0.977.系统总重约为12 kg,其中所设计的R型三相自耦变压器重量为4.45 kg.     

115V/400Hz三相高功率因数高压电源的设计

介绍了115 V/400 Hz三相高功率因数高压电源的工作原理,阐述了三相脉宽调制整流器的电路拓扑、数学模型、dp轴两相解耦的双闭环控制方法以及基于TMS320F2808全数字控制器的硬件配置和软件流程,说明了全桥逆变电路和倍压整流电路的设计方法,最后分析了样机的实验波形和测试结果,证明了高功率因数高压电源设计方法的正确性和有效性。     

Implementation of a three-level rectifier for power factorcorrection

In this paper, a new single-phase switching mode rectifier (SMR) for three-level pulse width modulation (PWM) is proposed to achieve high input power factor, low current harmonics, low total harmonic distortion (THD) and simple control scheme. The mains circuit of the proposed SMR consists of six power switches, one boost inductor, and two DC capacitors. The control algorithm is based on a look-up table. There are five control signals in the input of the look-up table. These control signals are used to control the power flow of the adopted rectifier, compensate the capacitor voltages for the balance problem, draw a sinusoidal line current with nearly unity power factor, and generate a three-level PWM pattern on the AC side of adopted rectifier. The advantages of using three-level PWM scheme compared with two-level PWM scheme are using low voltage stress of power switches, decreasing input current harmonics, and reducing the conduction losses. The performances of the proposed multilevel SMR are measured and shown in this paper. The high power factor and low harmonic currents at the input of the rectifier are verified by software simulations and experimental results from a laboratory prototype     

A new control scheme for single-phase PWM multilevel rectifier withpower-factor correction

A new control scheme for a single-phase bridge rectifier with three-level pulsewidth modulation is proposed to achieve high power factor and low current distortion. The main circuit consists of a diode-bridge rectifier, a boost inductor, two AC power switches, and two capacitors. According to the proposed control scheme based on a voltage comparator and hysteresis current control technique, the output capacitor voltages are balanced and the line current will follow the supply current command. The supply current command is derived from a DC-link voltage regulator and an output power estimator. The major advantage of using a three-level rectifier is that the blocking voltage of each AC power device is clamping to half of the DC-link voltage and the generated harmonics of the three-level rectifier are less than those of the conventional two-level rectifier. There are five voltage levels (0, ±V_DC/2, ±V_DC) on the AC side of the diode rectifier. The high power factor and low harmonic currents at the input of the rectifier are verified by software simulations and experimental tests     

Dynamic and steady state analysis of a three phase buck rectifier

Current source rectifiers among other alternatives, offer several advantages over line commutated rectifiers. Advantages include displacement power factor control and reduced line current harmonic distortion. This paper analyzes the current source rectifier (CSR) in transient and steady state, the models are developed in a synchronous reference frame. The load behavior is characterized for two load conditions, resistive load or, in general, increasing current for increasing voltage, and constant output power, decreasing output current for increasing voltage. Constant power operation can occur for a converter system supplying a pulse width modulation (PWM) inverter with high dynamics. Several static converter characteristics such as power factor, real and reactive power are analyzed for both types of load. Transient characteristics are analyzed for both types of load by exact small-signal model with full set of equations     

A Simple Control Method for a Switching Rectifier with Power Transistors

A very simple control method for a high-frequency switching rectifier with power transistors is presented. The converter uses six semiconductor switches with turn-off capability to connect directly the three-phase source to the load. Each semiconductor switch is composed by two power MOSFET transistors. The control method is based on the fictitious bipolar source concept. A two-level controller with hysteresis is used to control the load current. The converter accepts power flow in both directions, does not need large storage elements, works with good power factor, and can generate output frequencies higher than the source frequency, without affecting the quality of the output current. The control and logic circuits of the rectifier are very simple, due to the high controllability of the bidirectional switches. The performance of the converter is investigated experimentally in the four-quadrant speed control of a dc machine.     

Control techniques for a high power factor multilevel rectifier based on double boost converter

In this paper three novel control schemes for the single-phase ac/dc converter with two-level or three-level pulse width modulation are proposed to improve the power quality. A diode rectifier with two power switches is adopted as a power factor correction circuit to achieve high power factor and low harmonic distortion. The proposed control schemes are based on look-up tables with a hysteresis current controller instead of the conventional complex control algorithm. The proposed control scheme can (1) draw a sinusoidal line current, (2) achieve a unity power factor and (3) improve voltage unbalance problem on the dc bus capacitors. The software simulations and experimental results are shown to verify the proposed control algorithms. It is shown that the measured harmonic currents and input power factor satisfy the international standard requirements such as International Electrotechnical Commission 1000-3-2.     

Single-phase integrated power quality compensator based oncapacitor-clamped configuration

A control scheme of an integrated power quality compensator, which employs an active rectifier to work simultaneously as an active power filter (APF) to decrease current harmonics, is proposed. The employed rectifier is based on a capacitor-clamped configuration to produce multilevel pulsewidth modulation waveforms which result in low voltage stress and low conduction loss on the power switches. The proposed active rectifier is controlled to track the supply current to be a sinusoidal wave with low current harmonics. The advantages of the proposed control scheme are high power factor, low current harmonics, no complicated calculations for current harmonics elimination, and no dedicated APF needed for harmonic elimination. The experimental results are used to verify the validity and effectiveness of the proposed control scheme     

Digital implementation of a line current shaping algorithm for three phase high power factor boost rectifier without input voltage sensing

In this paper the implementation of a simple yet high performance digital current mode controller that achieves high power factor operation for three phase boost rectifier is described. The indicated objective is achieved without input voltage sensing and without transformation of the control variables into rotating reference frame. The controller uses the concept of resistance emulation for shaping of input current like input voltage in digital implementation. Two decoupled fixed frequency current mode controllers calculate the switching instants for equivalent single phase boost rectifiers. A combined switching strategy is developed in the form of space vectors to simultaneously satisfy the timing requirements of both the current mode controllers in a switching period. Conventional phase locked loop (PLL) is not required as converter switching is self-synchronized with the input voltage. Analytical formula is derived to obtain the steady state stability condition of the converter. A linear, low frequency, small signal model of the three phase boost rectifier is developed and verified by measurement of the voltage control transfer function. In implementation Texas Instruments's DSP TMS320F240F is used as the digital controller. The algorithm is tested on a 10-kW, 700-V dc, three phase boost rectifier.     

Vienna整流器单周控制技术研究

通过分析三相三开关三电平(Vienna)整流器的工作原理,研究了该整流器的单周控制策略,并采用电压外环和电流内环的双闭环控制,实现了Vienna整流器的可靠稳定、低谐波畸变特性。基于Matlab仿真平台,搭建了Vienna整流器的仿真模型,仿真结果表明,基于单周控制方法的8 kW三相PFC整流器,控制结构简单,系统可靠稳定,谐波畸变率＜3%,功率因数可达99%。     

A DSP-based implementation of a nonlinear model reference adaptive control for a three-phase three-level NPC boost rectifier prototype

In this paper, the design and the implementation of a model reference adaptive control (MRAC) applied to a three-phase three-level neutral-point-clamped (NPC) boost rectifier are presented. This control strategy is developed with a view to regulate dc output and neutral point voltages and to reduce the influence of parameter variations while maintaining unity power factor. A nonlinear multiple-input multiple-output (MIMO) state space model of the rectifier is then developed in dq0 reference frame. The proposed controller is based on the use of a feedback linearization technique followed by a robust MRAC scheme allowing the design of a suitable controller applied to the plant. The control law is designed in Simulink/Matlab and applied to the converter via a 1920-Hz pulse width modulator both executed in real time using the DS1104 DSP of dSPACE. A 1.25 kW laboratory prototype is developed for validation. The experimental results are given for different operating conditions: nominal power operation, balanced and unbalanced dc load steps, boost inductor variation, and reactive power control. The proposed control law performs perfectly in a wide operation range giving low output voltage ripple, low line-current THD, a small overshoot and a fast settling time under system parameters variation.