A new high-performance AC/DC power factor correction switching converter based on one-cycle control technology and active floating-charge technology

A new family of converters,high-performance AC/DC power factor correction(PFC) switching converters with one-cycle control technology and active floating-charge technology,was derived and experimentally verified.The topology of a single-phase CCM and DCM Boost-PFC switching converter was also analyzed.Its operating prniciples and control methods were expounded.Based on these,a new type of AC/DC switching converter circuits for PFC combined with one-cycle control technology was presented herein.The proposed AC/DC switching converter significantly helps improve the converter efficiency and its power factor value.

Design and Simulation for the Pulse High-Voltage DC Power Supply (HVPS) of 1.2 MW/2.45 GHz HT-7U Lower Hybrid Current Drive System

The superconducting tokamak HT-7U [1] has been designed by the Institute of Plasma Physics since 1998 and will be set up before 2003. The 1.2 MW /2.45 GHz HT-7U LHCD (Lower hybrid current drive) system which being the most efficient non-induction device can heat the plasma and drive the plasma current has been efficiently in operation 'owl and a particular design of the 2.8 MW/-35 kV high-voltage DC power supply has been already completed and will apply to the klystron of LHCD on HT-7 and the future HT-7U, and the project of the power supply has been examined and approved professionally by an authorized group of high-level specialist in the institute of Plasma Physics. The detailed design of the power supply and the simulation results are referred in the paper.

Operation Control Method of Relay Protection in Flexible DC Distribution Network Compatible with Distributed Power Supply

A novel operation control method for relay protection in flexible DC distribution networks with distributed power supply is proposed to address the issue of inaccurate fault location during relay protection,leading to poor performance.The method combines a fault-tolerant fault location method based on long-term and short-term memory networks to accurately locate the fault section.Then,an operation control method for relay protection based on adaptive weight and whale optimization algorithm(WOA)is used to construct an objective function considering the shortest relay protection action time and the smallest impulse current.The adaptive weight and WOA are employed to obtain the optimal strategy for relay protection operation control,reducing the action time and impulse current.Experimental results demonstrate the effectiveness of the proposed method in accurately locating faults and improving relay protection performance.The longest operation time is reduced by 4.7023 s,and the maximum impulse current is limited to 0.3 A,effectively controlling the impact of large impulse currents and enhancing control efficiency.

Programmable Voltage Regulating Method for 15 kV High Voltage DC Power Supply

In order to solve the disadvantages caused by mechanical slide rheostat that has big errors and low precision,a novel voltage regulation method for high voltage DC power supply was introduced.The key of this method were digital potentiometer MAXIM 5455 and linear photoelectric coupling LOC110,and application programs were compiled using Visual Basic which was graphical compiling language,furthermore the communication between exterior and computer was carried out by ICP7044D module,in consequence the output value of high voltage DC power supply could be regulated with computer.The measured results showed that this method could accurately,conveniently and rapidly regulate the output value of high voltage DC power supply.

TOPSwitch集成电路在DC/DC电源设计中的应用

文章介绍了PWM/MOSFET二合一的TOPSwitch系列集成电路及其在DC/DC电源设计中的应用,还介绍了基本反馈方式的DC/DC拓扑结构及其改进措施,并对由TOPSwitch集成电路构成的DC/DC电源进行了抗中子实验。

集成有源开关电感和Y源倍压单元的高增益DC-DC变换器

针对光伏发电系统中光伏组件电压等级的提升,提出一种集成有源开关电感和Y源倍压单元的高增益DC-DC变换器。所提变换器能够实现低开关管电压应力,具有高自由度电压调节能力,在满足一定升压条件下仍能保证电路的效率,在光伏发电中具有较大的应用潜力。对变换器的工作模态、器件电压电流应力、参数设计和损耗效率进行详细阐述。最后通过实验验证所提拓扑结构的可行性。

基于QFSK调制的DC-DC变换器功率/数据复合传输方法

传统电力线通信方案的硬件设计较为复杂。DC-DC变换器具有发送数据的潜能,可进行功率/数据复合传输。文中提出一种基于四进制频移键控(QFSK)调制的电力电子开关调制方案,通过调制开关频率将数据信息嵌入原始脉宽调制(PWM)信号中,使得电压纹波携带数据的频率特征;再通过基于滑动离散傅里叶变换的解调方案实现数据接收,最终实现功率/数据的同步传输。首先,证明了PWM信号与电压纹波频率一致的关系;然后,给出数据调制与解调的方案;以负载突变工况为例,通过对Buck变换器建模,分析功率变换暂态过程对通信的干扰影响;最后,搭建由两个Buck变换器组成的实验平台,验证了所提方案可实现20 kbit/s的通信速率;并以光伏优化器为应用背景,验证了所提方案的有效性。

一种应用于车载辅助电源的DC-DC变换器

以应用于车载辅助电源模块APM(auxiliary power module)的DC-DC变换器设计为研究对象,提出1种由三电平升压型TL-Boost(three-level Boost)拓扑和半桥LLC谐振拓扑构成的两级式DC-DC变换器拓扑结构,分析其工作原理。前级TL-Boost拓扑将宽范围的输入电压转换为稳定电压,保证了后级半桥LLC谐振拓扑的高效率运行。通过搭建实验平台并进行相关实验,结果验证了所提DC-DC变换器的可行性和正确性。

一种新型软开关双向大变比DC-DC变换器研究

目前,开关电源等电力电子设备主要的能量损耗集中在开关器件上的开关损耗,因此国内外学者对软开关技术进行了大量的深入研究,以期提高电力电子设备的效率。提出一种新型软开关双向大变比DC-DC变换器,通过软开关方案的设计与应用,减小了功率开关管电压尖峰,实现了各功率开关管相应的零电压开通与关断、零电流开通与关断,提升了变换器的效率。对所提变换器的工作原理和模态变化进行了详细的理论分析,并搭建了1台48~400 V、400 W实验样机,验证了理论分析的正确性。

AC/DC通信电源模块远场电磁辐射发射预测研究

AC/DC通信电源产生的电磁辐射易超过限值,对其电磁辐射机理和预测方法开展研究有助于改善电磁兼容性设计。首先,在分析AC/DC通信电源模块共模电磁噪声的形成源头和传播路径后,提出其远场电磁辐射可分解为由“输入端口”、“输出端口”共模电压驱动的2类辐射。然后,提出将共模电压驱动源与寄生辐射体的辐射传递函数相结合,进行远场电磁辐射预测的新方法;设计频谱分析仪+电阻衰减器,实现各共模电压驱动源的频谱测量;采用FEKO电磁仿真软件,通过数值计算得到各寄生辐射体的辐射传递函数。最后,实现了4 kW AC/DC通信电源模块辐射预测,并实测验证了其有效性。

增程式汽车12V DC/DC变换器输出熔断丝熔断问题分析及改进

增程式汽车作为当代传统燃油车向纯电动汽车过渡的车型,在汽车发展中占据着重要地位。DC/DC变换器作为增程式汽车的关键零部件之一,起着至关重要的作用。它将高压电池包输出的高压电转换为合适的电压,为整车及蓄电池供电,确保整车用电器正常用电需求的同时,保证低压蓄电池处于满电状态,是整车供电系统中不可或缺的一环。文章结合某增程式汽车DC/DC变换器输出熔断丝熔断导致蓄电池馈电的问题,进行深入排查,并确认问题发生的根本原因,进而提出优化改进方案,对提高增程式汽车供电系统的可靠性具有重要意义。

基于单片机的AC-DC变换电路设计

传统的AC-DC变换电路由于要通过高频变压器来实现电压变换,存在效率较低、电源的波纹很难降低等问题。因此,设计一种以单片机为核心控制器件的新型单相AC-DC变换电路。单相AC-DC变换电路设计结合BOOST开关器、输入负反馈和脉冲宽度调制,采用单片机辅助控制相结合的方式实现闭环控制,保证输出的稳定和高效。该电路包括全波桥式整流电路、BOOST开关器、电压反馈电路、电流采样电路和功率因数测量电路,通过负反馈控制UC3845芯片来改变PWM控制信号,从而调整BOOST开关器开关的通断,使输出电压稳定在36 V。单相AC-DC变换电路具有PFC功能,可通过LCD将实时的PF值进行检测,显示输出电流、输出电压、功率因数等数据。另外,在输出端设计了过流保护报警功能,该设计选取STC51单片机系列中的89C52RC芯片作为控制核心,结合电流电压检测共同来实现。实验结果表明,实测负载调整率为0.28%,电压调整率为0.28%,功率因数为0.91,说明所设计电路优于传统的AC-DC变换电路,具有转换率高的特点。

高功率密度DC/DC电源模块结构设计与封装

高效率、高功率密度是DC/DC电源模块永恒的发展趋势。以一种封装尺寸为38.72 mm×22.80 mm×7.21 mm、输出功率为320 W的DC/DC模块电源为研制对象,从结构设计、热设计、封装工艺等方面进行了系统的研究。DC/DC电源模块采用“夹心”工艺结构,以高导热塑封工艺封装,工作温度范围为-55~125℃,可靠性满足航空航天领域高可靠要求。

DCS系统冗余切换试验分析

DCS系统作为核电站的控制中心,其设备运行周期越长,存在的缺陷和隐患越多,设备故障率越高。为了排查重要设备的潜在故障和安全隐患,保证核电站设备的安全稳定运行,必须定期对DCS设备进行冗余切换试验,检查设备的可用性和冗余功能。冗余试验一方面检查长期运行设备的可用性,另一方面检查系统自动无扰切换功能。在核电停堆检修期间,仪控人员根据试验程序对DCS系统设备进行切换试验,检验系统中冗余设备的可用性。通过对设备的冗余切换试验,仪控人员全面完整地检查了DCS系统设备的健康状态和运行参数,并对存在隐患的设备进行了更换和维修。

Multi-converter Approach to Higher Power Density DC-DC Converter for 380 V DC Distribution System

Multi-converter approach based on the series and parallel connection topology of modular power converters has been proposed to realize higher power density DC-DC converter. The availability of the proposed approach has been verified through the design consideration and the experiment. The design consideration for two DC-DC converters has been carried out by utilizing the power converter exact loss simulator, and the design parameters to maximize their power densities have been extracted taking the trade-off between the conversion efficiency and the power density into account. The prototypes of a 2,400 W, 256-384 V boost chopper using SiC-MOSFETs and a 300 W, 32-48 V GaN-FETs boost chopper have been also developed based on the design. The SiC chopper achieved the efficiency of 97.8% and the power density of 12,8 W/cm3, and the GaN chopper accomplished 98.9% and 18.6 W/cm3 in the experiment. These results show the validity of the design and the availability of the proposed approach. The multi-converter approach enables the cost reduction of the modular power converters, and contributes to realizing the widespread use of power electronics converters in the future 380 V DC distribution system.

高效率DC/DC转换器在通信电源中的应用研究

文章旨在评估高效率直流/直流(Direct Current/Direct Current,DC/DC)转换器在通信电源中的应用,着重考察最小输出电压、效率、功耗以及瞬态响应等关键性能参数。通过深入研究TPS54160芯片,揭示在不同工作频率下该芯片的性能特点。最后,通过实验验证TPS54160芯片在通信电源中的性能表现,旨在为通信系统的电源设计提供参考和指导。

Exact Dynamic Modeling of PWM DC-to-DC Power Converters—Part I: Continuous Conduction Mode

A general approach is presented by which the exact frequency response of any transfer function of switched linear networks can be determined. This is achieved with a describing function approach using a state space equation formulation. This work presents a somewhat simplified set of equations to one previously given by one of the authors. To demonstrate application of the general formulation, the frequency responses of switched networks used as PWM DC-to-DC converters operating in continuous conduction mode (CCM) under voltage mode control are derived. (The accompanying paper, Part II, will present results for converters operating in discontinuous conduction mode (DCM)). From the general sets of equations developed here, both the control to output and input source variation to output frequency responses are derived. The describing function approach enables exact frequency response determination, even at high frequencies where the accuracy using average models may be compromised. Confirmation of the accuracy of the derived models is provided by comparing the responses with those obtained using the commercial simulator PSIM on a PWM boost converter. The magnitude and phase responses are shown to match perfectly over the full range of frequencies up to close to half the switching frequency. Matlab code that implements the models is given such that the user can easily adapt for use with other PWM converter topologies.

Exact Dynamic Modeling of PWM DC-to-DC Power Converters—Part II: Discontinuous Conduction Mode

This paper follows on from the first paper, Part I, where a general formulation of a describing function approach to frequency response determination of switched linear networks, such as PWM converters, was simplified and updated. The models assume a piecewise linear state space equation description of the system and results in a closed form solution for the sought after frequency response. In Part I, model derivation was demonstrated for the case of PWM converters operating in the continuous conduction mode (CCM). This operating mode does not feature any state dependent switching times. In this paper, Part II, frequency response models for any transfer function for PWM converters operating in discontinuous conduction mode (DCM) are derived based on the theory presented in Part I. This operating model features state dependent switching times. The describing function models developed are exact and therefore, in terms of accuracy, are to be preferred over averaged models which are widely used. The example of a boost dc-to-dc converter operating in DCM is simulated to obtain the control to output and input to output frequency responses and are compared with the models derived here. Excellent agreement between the simulated and model responses was found. Matlab code implementing the analytical models is also presented which the user can adapt for any other PWM converter topology. The models derived here may be used as a basis from which simplified models may be derived while still preserving required accuracy.

基于切换线性系统理论的DC-DC变换器控制系统的能控性和能达性

该文将电力电子电路视为一类混杂动态系统,尝试在DC-DC变换器控制系统研究中引入切换线性系统的概念和理论。将基本DC-DC变换器建立为切换线性模型,由此提出DC-DC变换器能控性和能达性等基本控制特性,为DC-DC变换器控制系统的优化控制和其它控制策略的实现提供理论依据。以Buck变换器控制系统设计为例进行仿真验证,分析了能控性和能达性研究的理论意义。该文的研究还表明,研究方法也适应于其它电力电子电路能控性和能达性的研究。

基于双重移相控制的双向全桥DC-DC变换器动态建模与最小回流功率控制

通过分析双重移相控制下双向全桥DC-DC变换器的软开关约束条件及功率传输特性,提出了满足软开关条件的基于最小回流功率的双重移相控制策略,建立了双重移相控制下变换器的动态小信号模型。最后,通过实验样机,分析了基于最小回流功率双重移相控制策略的变换器动态和稳态特性,对动态模型和最小回流功率控制策略进行了验证。实验结果表明了采用基于最小回流功率控制对提高变换器效率的有效性。