A high-power-factor PWM rectifier without voltage sensors

Pulsewidth modulation (PWM) control techniques for rectifiers are widely used to improve the source current waveform and the input power factor. Recently, methods to reduce the number of detectors have been studied to simplify the system configuration and control of such rectifiers. It is known that a voltage detector on the ac side can be omitted, though a voltage detector on the dc side is needed for adjustment of the dc output of a PWM rectifier. In this paper, a method for controlling a single-phase rectifier without any voltage sensor is proposed. The ac-side voltage can be estimated from the input-reactor voltage when the ac side of the bridge is short-circuited. The reactor voltage is easily obtained by multiplying the inductance of the reactor by the derivative of the source current measured. The dc side voltage can be estimated by calculating the difference between the source voltage at the beginning of every switching period and the reactor voltage sampled and held in the previous bridge conduction mode. This paper describes the control scheme, its implementation, and the performance characteristics of the rectifier. The usefulness of the rectifier is confirmed by experiment. This method is applicable to various types of PWM rectifiers. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 120(4): 90–96, 1997     

三相高功率因数PWM整流器双闭环控制系统设计

引入电压干扰补偿,建立三相高功率因数脉宽调制(PWM)整流器的简化数学模型,该模型既能真实反映PWM整流器的运行状态,又便于控制系统设计。针对电流内环的控制要求,根据电流内环的斜坡响应特性设计其比例积分(PI)调节参数,提出依照I“TAE性能最佳准则”的PI调节参数设计方法;针对电压外环的控制要求,根据电压外环的阶跃响应特性设计其PI调节参数,提出依照“阶跃响应最佳准则”的PI调节参数设计方法。仿真波形和实验数据验证了简化数学模型和PI调节参数设计方法的正确性。     

A single-reset-integrator-based implementation ofline-current-shaping controller for high-power-factor operation offlyback rectifier

The objective of this paper is to present a simple yet accurate implementation of a resistor-emulator-type line-current-shaping controller for high-power-factor operation of a flyback rectifier. The important feature is that input voltage sensing is not required. In the circuit realization of the controller, no multiplier is used. Current shaping is performed directly on the input filter inductor current. The modulator uses only one reset integrator for the generation of duty ratio. The analysis presented in this paper shows the effect of input filter capacitance on discontinuous conduction mode of operation of the flyback inductor. Design equations for selection of the input filter components are derived. A low-frequency small-signal model of the rectifier is developed and verified by measurement up to 1 kHz. The performance of the controller is first tested by the SABER circuit simulator package. Then, a 100-W 110-V AC input 50-V DC output single-phase flyback rectifier prototype is built for experimental verification     

Force commutated three level boost type rectifier

A new force commutated three level boost type rectifier is proposed in this paper. The rectifier has the characteristics of drawing nearly sinusoidal current from the utility with unity fundamental power factor. High reliability is possible due to its shoot-through free structure. A doubled DC bus voltage compared to a normal two-level rectifier is also possible because of the neutral point clamping. The operating principle, steady state analysis, input current and neutral point voltage control schemes, as well as detailed experimental results are presented in this paper     

Harmonics reduction of three-phase boost rectifier by modulating duty ratio

Line currents of three-phase diode bridge rectifier suffer from high THD. This THD is higher than IEEE standards. Injection of six harmonic components from the DC bus back to the duty ratio of the boost converter connected to the three-phase diode bridge rectifier reduces the THD of the utility line current. In this study a sine wave and a triangle wave with six times the fundamental frequency is presented. The analysis has been carried out to reduce THD of the utility line current of three-phase boost rectifier. The THD of the utility line currents depends on the amplitude and phase-shift of the six-order component injected to the duty ratio of the boost converter. A complete mathematical and simulation analysis of the injection technique has been carried out. The mathematical analysis and simulation results of 6 kW prototype system show the superiority of the proposed injection technique.     

Elimination of low-frequency harmonics caused by PWM in athree-phase soft-switched boost rectifier

This paper presents three major causes of low-frequency harmonics in a high-frequency soft-switched three-phase pulsewidth modulation (PWM) boost rectifier: pulsewidth limits; an improper space-vector modulation scheme; and dead time. Among these, the pulsewidth limits are related to soft-switching techniques. To eliminate undesirable low-frequency harmonics, each cause is illustrated and a solution is provided. Both simulation and experimental results prove the effectiveness of the proposed solutions. Due to the similarities between boost rectifiers and voltage-source inverters, the conclusions of this paper are also applicable to high-frequency PWM voltage-source inverters     

软开关逆变器的研究

介绍了软开关逆变器的基本构成和软开关的工作原理,分析了DC/DC直流变换、吸收电路和DC/AC逆变电路。据工程技术要求对电路的关键参数进行了详细的分析和计算。通过计算确定直流环节开关频率Fs为50 kHz,占空比D取0.45,变压器变比系数选择1.1,滤波电感3 mH,DC/DC功率管的选择选择PHILIPS公司生产的BYV26C超快软恢复二极管,DC/DC整流管的选择IXYS公司生产的快速软恢复二极管DSEI30-06。最后通过实验分析了不同输入电压时满载的效率值。     

A novel slip‐power recovery system using a PWM boost rectifier

A novel compact slip‐power recovery system having sinusoidal rotor currents is proposed. In this system, a PWM boost rectifier is used as a substitute for a diode rectifier and a boost chopper in a conventional compact slip‐power recovery system. The conventional compact system has the disadvantage that it has a rectangular rotor current, and a motor torque with large ripple, because a diode rectifier remains in the system. Also, the rotor current cannot reach the current reference value near the synchronous speed, because the voltage drop caused by the resistance of the semiconductor devices and so on cannot be neglected when the rotor voltage becomes smaller near the synchronous speed. The use of the system proposed in this paper has solved these problems. The effectiveness of the proposed system was verified through computer simulations and experiments. As a result, the proposed system brings the sinusoidal rotor current, the small torque ripple, and wide controllable range near the synchronous speed. © 2002 Scripta Technica, Electr Eng Jpn, 139(2): 52–60, 2002; DOI 10.1002/eej.10012     

Fuzzy controller tuning of a boost rectifier unity power factor correction by experimental designs

This paper shows the validity of experimental designs as an efficient on-site tuning tool for fuzzy controllers, dedicated to electrical engineering applications with multi-objective criteria. Our purpose is to improve the input and output system characteristics that is to say the global quality of the electrical power in a boost rectifier with unity power factor correction. The desirability notion here combines the time dynamic and harmonic criteria and illustrates the trade-off that has to be satisfied between different properties.     

铁硅铝磁芯升压电感的设计

铁硅铝粉芯饱和磁感应强度高,同时具有良好的高频磁性能及低损耗、低成本等特点,而获得广泛应用.选择铁硅铝粉芯作为Boost升压电感磁芯,采用迭代方法对铁硅铝磁芯进行优化选择,归纳出铁硅铝磁芯的设计过程,并通过实例证实了铁硅铝磁芯在大电流下不易饱和及低损耗的特点.     

全数字升压逆变器设计

介绍用ADMC331 DSP为控制核心的升压型逆变器的设计与实现，阐述了逆变器的总体构成和PWM信号的产生，实践证明该系统有很好的运行性能和实用价值。     

三相SVPWM整流器主电路参数的设计

用状态空间法建立三相SVPWM整流器VSR的数学模型,并根据此模型建立了三相SVPWM整流器的等效电路模型,在理论上分析了该模型的交流侧和直流侧的稳态工作情况,分析了交流侧电感和直流侧电容对整个主电路起着至关重要的作用,并提出了完整的主电路参数计算方法。     

Design and application of semiconductor rectifier transformers

The design of semiconductor rectifiers made obsolete the older mercury-arc rectifiers. Accordingly, the transformer standards were modified to address the differences in the two types of transformers supplied for these applications. Short-circuit problems were reduced with the new technology, but harmonic heating became a bigger problem. The Transformers Committee of the IEEE Power Engineering Society developed the new standard for semiconductor power rectifier transformers. This paper intends to highlight some of the major aspects of how specification, design, and testing of semiconductor rectifier transformers have changed based on the new standard, as well as other design and application consideration.     

Analysis and elimination of the output voltage imbalance for a half‐bridge boost rectifier under mismatched loads

In this letter, the voltage imbalance between the dual output DC voltages of a half‐bridge boost rectifier with mismatched loads is analyzed by adopting an averaged circuit model. A compensating signal proportional to the voltage difference is added in the current command to eliminate the voltage imbalance. In addition, the adverse effects of the compensating current to the input power factor are discussed. Experimental results on a prototype circuit are given to confirm the theoretical analysis. Copyright © 2007 John Wiley & Sons, Ltd.     

Three-phase buck/boost-type high-power-factor switching converter

The harmonic pollution caused by ac-to-dc converters has been of great concern. To overcome this problem, several power-factor-correction (PFC) converters have been developed and applied in recent years. However, several power converter systems, such as the motor drive system, with a wide V/F control range, uninterruptible power supply system and dc power supply system with universal input voltage range, require an ac-to-dc converter or an off-line converter (preregulator) with a wide output-voltage control range in order to be highly efficient. However, the most conventional PFC converters employ a voltage-fed or current-fed type topology and they have a lower or upper limitation of the output-voltage control range. Thus, they do not realize sufficiently high-system efficiency. On the other hand, a buck/boost converter has a wide control range of the output voltage and acts in PFC operation under an appropriate control technique. Thus, study of the possibility of using the buck/boost ac-to-dc converter with PFC and a wide output-voltage control range is important to the realization of harmonic-free and efficient power conversion systems. In this paper, the author proposes a three-phase bridge-type ac-to-dc converter system with a high input power factor and a wide output-voltage control range. The controller of the proposed system includes the following two new techniques. One is the pulse integral value modulation that compensates modulation errors in conventional pulse-width-modulation caused by dc current ripples or fluctuations of the current pulse amplitude. The other is a switching pulse pattern generator, using the idea of equivalent pulse current source for the bridge as a way to simplify the pulse pattern generation process. This paper describes the proposed converter system, the control and modulation principles, and experimental results that show the reliability and usefulness of the proposed buck/boost converter system. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 118 (2): 41–55, 1997     

双向高效高功率因数电动汽车充电机研究

电动汽车作为一种高效、节能、零排放的交通工具,将成为未来城市的主导。而对充电机的研究,将直接影响未来电动汽车的发展。针对传统电动汽车充电机的结构,提出了一种高效且高功率因数、低谐波含量、能量双向流动的充电机结构。该结构前级采用三相电压型PWM整流器,后级DC/DC变换电路采用电流可逆斩波电路。针对前级,推导了一种功率前馈的无差拍控制,该方法实现了系统的快速、无差整流。针对后级,提出了一种基于马斯定律的自适应多阶段恒流充电控制,能够有效地延长蓄电池的使用寿命和缩短充电时间。最后通过仿真与实验验证了所提结构与方法能够实现充电机的双向高效、高功率因数、低谐波功能。     

KHS-15000/75整流电源的数字化设计

介绍了KHS-15000/75整流电源的基本情况.该电源为稳流型直流电源,输出为直流15 kA/75 V.主电路由双反星整流电路组成,采用全数字双CPU控制.主控制系统采用16位的80C196KC单片机,数字触发器由8位的89C51单片机组成,2片单片杌采用并行接口通信.控制系统的监控软件运用了模块化编程,给出了系统主控软件、系统初始化与运行前自诊断、调压稳流运行方式等流程图.对设计的难点和关键技术问题:数字触发控制系统、系统自诊断、故障识别与保护等提出了相应的解决方案.     

PWM整流器中优化变结构控制策略的设计

提出了PWM整流器的等效电路并在dq坐标系下进行了建模分析,对采用变结构的电流控制环和PI 电压控制环的双闭环的控制器进行了深入分析。针对变结构控制存在的不足,采用PID趋近率来减小变结构控制的抖振及到达滑模面的时间,在对PID趋近率设计进行理论分析的基础上提出了一种优化变结构控制策略。对该优化控制器的设计进行了详细的分析并进行了仿真与实验验证,结果表明所提出的优化变结构控制策略可以实现PWM整流器的单位功率因数运行,且输入电流畸变较小,在负载变化时可以保证系统的快速调节,动、静态调控特性较好。     

Design and control of an LCL-filter-based three-phase active rectifier

This paper proposes a step-by-step procedure for designing the LCL filter of a front-end three-phase active rectifier. The primary goal is to reduce the switching frequency ripple at a reasonable cost, while at the same time achieving a high-performance front-end rectifier (as characterized by a rapid dynamic response and good stability margin). An example LCL filter design is reported and a filter has been built and tested using the values obtained from this design. The experimental results demonstrate the performance of the design procedure both for the LCL filter and for the rectifier controller. The system is stable and the grid current harmonic content is low both in the lowand high-frequency ranges. Moreover, the good agreement that was obtained between simulation and experimental results validates the proposed approach. Hence, the design procedure and the simulation model provide a powerful tool to design an LCL-filter-based active rectifier while avoiding trial-and-error procedures that can result in having to build several filter prototypes.     

一种对高速脉冲边沿整形、调整的设计方案

随着高速脉冲的广泛应用,作为决定脉冲质量的重要参数,脉冲上升、下降时间也越来越受到重视。针对高速脉冲发生中对脉冲边沿陡峭、可控的要求,本文提出了一种使用隧道二极管对脉冲边沿整形,利用场效应管开关和恒流源充放电电路控制脉冲边沿时间的方案,并对其电路和隧道二极管的工作原理进行了具体分析。从试验结果看,该方案能将脉冲的边沿时间整形至800ps左右,同时实现边沿时间的可控调整。