Reducing the minimum output power of soft-switching inverter arc welding power supplies

The full-bridge zero-voltage and zero-current switching inverter, which can adjust the output power by keeping the duty-cycle of lagging arm constant, changing the duty-cycle of leading arm, is a common circuit topology of soft-switching inverter arc welding power supplies. However, the output power still remains a certain value when the duty-cycle of leading arm decreases to zero. The working-mode of soft-switching inverter and the waveforms of major parameters with the condition of duty-cycle of leading arm being zero are studied in this paper. U-1 characteristic experiments prove that the minimum output power of soft-switching circuit, which depends on the charged voltage of capacitors in parallel with leading arm, can be decreased by reducing the duty-cycle of lagging arm. By switching working-modes between half-bridge and full-bridge, the output power can swing from zero to the power rating.

Soft switching arc welding power source using output inductor as resonant inductor

Full bridge Zero Voltage Switch PWM converter combines advantages of the PWM control technique and resonant technique. However, Full ZVS is achieved only under large load current because resonant tank of this circuit is made up of the parasitic capacitance of the power semiconductors and the leakage inductor of the transformer primary. In this paper two saturable inductors as magnetic switches are added to secondary, so output inductor is always reflected to primary and assists resonant transition. Full ZVS is achieved under lower load current. The above mentioned investigated results are validated by the computerized simulation and hardware circuit experiment.

Air-Water Cooling System for Switch-Mode Power Supplies

The results are presented of an experimental investigation of heat transfer in an air-liquid cooling system for a Switch-Mode Power Supply (SMPS) for TV digital power amplifiers. Since these SMPSs are characterized by high power and high compactness, thereby making the standard cooling techniques difficult to be used, a new cooling system is developed, using water and air as the cooling media. The active components (MOSFETs) are cooled with a liquid cold-plate, the passive ones (condensers, transformers, coils) with an air flow, in turn cooled by the cold-plate. By inserting the cooling system in an experimental tool where it is possible to control the cooling water, measurements are made of temperature in the significant points of the SMPS. The electric efficiency is also measured. The evaluation of the thermal performance of this cooling system is useful in order to limit its maximum operational temperature. The efficacy of the cooling system is demonstrated;the trends of efficiency and power dissipation are evidenced.

Simulation realization of skip cycle mode integrated control circuit in the switching power supply with low standby loss

This paper explores and proposes a design solution of an integrated skip cycle mode （SCM） control circuit with a simple structure. The design is simulated and implemented with XD10H-1.0μm modular DIMOS 650 V process. In order to meet the requirement of a wide temperature range and high yields of products, the schematic extracted from the layout is simulated with five process corners at 27℃ and 90℃. Simulation results demonstrate that the proposed integrated circuit is immune to noise and achieves skipping cycle control when switching mode power supply （SMPS） works with low load or without load.

High-power High-efficient and Simplified High-frequency Switching Power Supply for Electrolytic Plating

针对大功率电解电镀开关电源的输入整流级引起的无功和谐波等电能质量问题,研究了一种基于高效PWM整流的高频开关电源。该电源前级整流器仅用4个开关管来进行PWM整流,后级采用半桥逆变器进行高频变换,显著减少了开关数量。针对三相四开关PWM整流器,推导一种基于开关模型的无差拍控制方法,该方法可实现系统的快速、无差整流。针对多台开关电源的并联均流问题,提出一种基于虚拟阻抗的自均流控制方法,可实现多台电源的均流稳定运行。通过仿真与实验验证了所提结构和控制方法的正确性。

Analysis of Switching Overvoltage in Regional Grid with Small Hydropower Plants

Present-day small hydropower plants (SHPs) have a large development potential because of the increasing interest in renewable resources and distributed energy generation, therefore, there are many SHPs in places of China where are rich in water resources. However, it has caused overvoltages in the distribution network, and which is even worse for the switching overvoltage such as isolated network operation, changing power supply path. The simple network model is used to analyze the reasons of the switching overvoltage, and the simulation software DIgSILENT/PowerFactory is used to check out the results of the theoretical analysis.

Analysis and Design of a Kind of Improved Parallel Resonant Converters

Traditional transformer in high-voltage power supplies has many disadvantages such as high turn’s ratio, large volume and great design difficulties. Parallel resonant converters (PRCs) are widely used in high-voltage power supplies. A kind of high-voltage circuit topology can be formed by combining PRCs and voltage-doubler rectifier, which is called parallel resonant dual voltage converters (PRDVCs). In PRDVCs both voltage-doubler rectifier and transformer can boost voltage, which reduced turn’s ratio and volume of the transformer, making it easier to produce. Thus it not only realizes the high-voltage output, but also realizes the miniaturization of high-voltage power supply. Three modes of the converters were researched and simulated. Converting conditions of three modes were given. At last, PRDVCs was used to design a 5000V/50mA high-voltage power supply. The waveforms and results of the experiment were given, which validated the feasibility of the converters and its conversion efficiency might be improved to 93%.

A Study of High-Power Thyristor Switch of Poloidal-Field Power Supply System in HT-7U Super-Conductive Tokamak

Through theoretical analysis of thyristor switch, criterion of turn-off was derived for the design of thyristor switch. The expression of parameter design and its math model during the turn-off were deduced. The simulation and experiment have been accomplished to validate the analysis.

Features and Prototypes of HTS High Q Resonant Circuit

High Te superconductor （HTS） technology has been used to develop a unique high Q resonant circuit. Such circuit or device has some special characteristics such as very high voltage generation. Theoretical study and experimental approaches have proceeded for the concept verification. This paper presents the theory about this high Q resonant circuit. The operation principle of the circuit is described. A practical prototype for HTS high voltage generation is also demonstrated. The experiment result shows that very high voltages can be achieved by the developed method using HTS technology.

Research on protection system of resonant network in CSNS magnet power supplies

Purpose Chinese Spallation Neutron Source(CSNS)is one of the key projects of China,in which the main magnet power supplies adopt the structures of resonant networks(Wang et al.in Sci China Phys Mech Astron 54(Suppl 2):239-244,2011).Since each network contains a lot of components,and the working state of all the components will affect the whole accelerator,it is necessary to monitor the operation of each part in the resonant network.Methods In this protections system,a supervision to 314 switch signals and 118 analog signals is realized using a chip of field programmable gate array(FPGA).The details about the hardware and software designs are introduced in this paper.Results This protection system has been used in CSNS project,and the result proves that the RCS has been well monitored by this system.Conclusions This system is a self-developed protection system according to the engineering needs of CSNS.It can realize the real-time monitoring and protection of the working state of resonance network by processing a large number of data using FPGA.

智能开关电源集成电路TOPSwitch的分析

近年来 ,由于便携设备的增多 ,对供电单元电路小型化的要求越来越迫切 ;各国政府对电源系统环保 节能的要求也更加严格。这些都要求有效率更高、集成度更高的开关电源加以配合。本文反向剖析了美国 Power Integration公司的 TOPSwitch系列智能开关电源集成电路芯片 ,在系统地分析及全面的计算机仿真的基础之上 ,给出该电路的工作原理、设计方法及其应用。该集成电路除了一般的 PWM控制功能外 ,还集成了自动重启功能 ,过流、过热保护功能 ,大功率 MOSFET等。具有效率高 ( AC/DC转换效率可高达 90 % )。外围元件少等特点 ,具有多项专利。是目前国际上最先进的智能开关电源产品之一。该电路的芯片生产工艺 ,更是集高压 ( 70 0 V)大功率 (数十瓦 )、数模混合、双极 /CMOS兼容等最先进的半导体技术于一体 ,世界上目前只有极少数几家公司具有生产该类电路的能力。

基于TOPSwitchⅡ的开关电源设计

TOPSwitchⅡ系列芯片是PowerIntegration公司生产的开关电源专用集成电路,他将脉宽调制电路与高压MOSFET开关管及驱动电路等集成在一起,具备完善的保护功能。使用该芯片设计的小功率开关电源,可大大减少外围电路,降低成本,提高可靠性。介绍其内部结构和工作原理,给出几种应用于反激式功率变换电路的典型用法,并给出一种反激式开关电源的实用电路。

用Topswitch芯片设计的反激式开关电源

Topswitch系列芯片是PowerIntegration公司生产的开关电源专用集成电路 ,它将脉宽调制电路 (PWM )与高压MOSFET开关管及驱动电路等集成在一起。使用该芯片设计的小功率开关电源 ,可大大减少外围电路 ,降低成本 ,提高可靠性。本文介绍了Topswitch系列芯片的工作原理及用该芯片制作的 3 0W反激式开关电源 。

一种基于TOPSwitch—GX的变频器开关电源

设计了一种基于TOPSwitch—GX的变频器专用开关稳压电源。该电源给系统控制板以及IGBT驱动电路供电,并保证该开关电源的电压稳定。文中主要介绍了TOPSwitch—GX系列芯片的特点、工作原理以及开关电源的设计,并着重分析了变压器的设计。该开关电源经现场检验,性能良好,满足设计的要求。

基于TOPSwitch-GX芯片的开关电源设计

采用将PWM控制器和MOSFET功率开关自启动电路、功率开关管、PWM控制电路及保护电路一体化的开关电源集成模块芯片是新一代中、小功率开关电源设计的主流发展趋势。电路的高度集成化有助于改善电源的电磁兼容性,极大地提高了电源的效率,简化开关电源的设计和缩短新产品的开发周期。详细阐述了TOPSwitch-GX系列芯片的特点,以无线电动钻充电电源为例,介绍了其电路设计的方法,其中着重介绍了运用计算机辅助软件PI Expert进行电源模块设计以及外围电路设计的情况。最后,给出了该开关电源性能测试结果。

一种基于Topswitch-GX的变频器专用开关电源

设计了一种基于Topswitch-GX的电机调速开关稳压电源。该电源给系统控制板以及IGBT驱动电路供电,并保证该开关电源的电压稳定。着重介绍了Topswitch-GX系列芯片的特点及工作原理以及开关电源的设计,并重点分析了变压器的设计。该开关电源经现场检验,性能良好,满足设计的要求。

基于TOPSwitch-GX系列芯片的开关电源设计与实现

介绍了美国PowerIntegration公司最新研制的开关电源集成芯片TOP-Switch-GX系列的主要特点,设计了一款基于此系列芯片的多路输出单端反激式开关电源,阐述了设计的主要步骤,给出了设计注意事项及试验结果。

基于TOPSwitch器件的单片开关电源设计

介绍了基于TOPSwtich器件设计实现的单片开关电源,分析了其基本的工作原理,给出了实用电路及主要单元电路的设计方法。

基于DPA-Switch的反激式开关电源设计

DPA-Switch是高集成度DC/DC转换芯片,集PWM控制器和MOSFET于一体,其电路简单,性能优异。文中利用DPA-Switch设计了一个单端反激式多路输出开关电源,简要介绍了变压器的绕制。实验结果表明该电源运行可靠,输出稳定。

TOPSwitch器件及其在开关电源功率因数校正电路的应用

介绍TOPSwitch器件的工作原理、特性以及在开关电源的功率因数校正中的应用,讨论了功率因数校正原理并给出了由TOPSwitch器件组成的开关电源的功率因数校正的实用电路。