功率MOSFET并联应用及研究

对作用在C类状态下频率为MHz以上的功率MOSFET并联均流情况进行了研究,分析功率MOSFET并联时造成不均流的各种因素,着重解析稳态和暂态电流平衡问题,并通过仿真提出一些解决方法和建议。实验结果表明,使用参数尽量一致的MOSFET管对称分布进行并联,并采取合理的电路布局,通过调节电路参数能获得较好的均流效果。     

SiC MOSFET并联动态电流不均衡的无源补偿策略

SiC MOSFET分立器件的并联结构已在中大功率应用中广泛使用,为了充分利用并联的优势,需解决并联动态电流不均衡问题.在SiC MOSFET特性参数中,阈值电压是影响并联动态均流特性最主要的参数.通过建立SiC MOSFET双管并联的电路模型,探究了并联动态电流不均衡的补偿策略,推导了阈值电压对SiC MOSFET开关管动态均流程度影响的公式.建立了含寄生电感的双管并联电路模型,提出了两种双管并联动态电流不均衡的无源补偿策略,即基于共源极寄生电感的补偿策略以及基于开尔文源极电感和功率源极寄生电感并联的补偿策略.通过仿真比较了两种无源补偿策略下的开关总损耗.最后,优化了基于开尔文源极电感和功率源极寄生电感并联的补偿策略,并通过双脉冲实验验证了此并联补偿策略下的动态均流效果.     

TPAK SiC车用电机控制器功率单元的并联均流设计与实现

SiC金属-氧化物-半导体场效应晶体管(MOSFET)作为车用电机控制器功率单元的核心器件，其并联不均流问题是影响电机控制器安全稳定运行的关键因素。对于热增强塑料封装(TPAK)SiC MOSFET功率模块实际应用中的不均流问题，首先通过理论推导和仿真，对影响SiC并联均流的器件参数、功率回路参数、驱动回路参数进行了全面的分析总结。然后结合仿真结果对电机控制器进行均流优化设计，其中包括对TPAK SiC MOSFET进行测试、筛选和分析，减小器件参数分散性的影响；基于器件开关特性，对功率模块的驱动回路采用单驱动器多推挽结构，减小驱动回路对并联均流的影响；设计了一种叠层母排结构，在ANSYS Q3D中提取到功率回路寄生电感为9.649 nH,采用ANSYS Q3D和Simplorer进行联合双脉冲仿真，电流不均衡度小于3%。最后，进行了电机控制器样机的试制及测试，实际测试结果表明电流不均衡度小于5%,验证了在车用电机控制器应用中TPAK SiC MOSFET模块均流设计的可行性。     

功率MOSFET并联驱动特性分析

并联MOSFET非常适合于在低电压、大电流下工作.基于IRFS4227PBF功率MOSFET,分析和测试了在一定散热环境下MOSFET结温的收敛特性与漏极电流的关系,说明了MOSFET的实际电流容量受散热条件制约,并以此确定在额定电流下需要并联的个数.用PSPICE电路仿真论述了外围电路Q值和功率管参数等因素对并联驱动的动态均流特性的影响.在此基础上搭建实验平台,成功实现了8个MOSFET并联在高频状态下的稳定工作.     

MOSFET器件并联实验研究

采用图腾柱的驱动方式,设计了应用于IXYS公司的功率MOSFET器件DE375-102N12的驱动电路。单个开关在多脉冲下具有良好的脉冲一致性。以该功率MOSFET器件进行的6个并联实验说明,影响并联的MOSFET的动态均流的主要参数是放电回路中的回路电感和寄生电感,电路板的布局与布线对并联的功率MOSFET有很大的影响,良好的布局可以大大提高电路的性能。     

基于电流检测的飞机地面电源同步整流控制

三相整流器作为飞机地面电源的前级为后级电力变换提供稳定的直流母线。飞机地面电源的容量可达100~200kVA,传统的二极管整流方案效率低、损耗大、发热量高、散热问题严峻。针对上述问题提出了一种基于电流检测的大功率同步整流控制方案,其中主电路采用多个功率MOSFET并联取代传统的整流二极管。通过分析整流电路各开关器件的通断状态与输入电流的关系,明确各开关器件的动作规律;进一步检测输入三相电流的大小与方向,提出功率MOSFET的同步整流驱动控制方案。然后考虑实际工程应用因素,设计电流回差方案以产生各功率MOSFET的驱动信号,并考虑霍尔器件、采样电路与控制电路的延迟对回差的各阈值进行修正。最后通过Simulink仿真及工程样机实验平台进行验证,结果显示本文所提方案可有效实现MOSFET的同步整流功能,提高了整流电路的效率,降低了系统的热损耗。     

MOSFET管并联应用时电流分配不均问题探究

并联应用时MOSFET管会产生电流分配不匀的现象,为减小此问题造成的不良影响,只能通过实验确定有关的电路参数。这里用数学方法详细分析MOSFET管的特性参数和电路参数对静态和动态漏极电流分配不匀的影响,推导出反映漏极电流分配不匀程度和对漏极电流上升速度影响程度的精确计算公式,为在实际工作中减小电流分配不匀的影响提供理论依据。     

MOSFET管并联应用时电流分配不均问题探究

并联应用时MOSFET管会产生电流分配不匀的现象,为减小此问题造成的不良影响,只能通过实验确定有关的电路参数.这里用数学方法详细分析MOSFET管的特性参数和电路参数对静态和动态漏极电流分配不匀的影响,推导出反映漏极电流分配不匀程度和对漏极电流上升速度影响程度的精确计算公式,为在实际工作中减小电流分配不匀的影响提供理论依据.     

IGBT芯片参数对瞬态均流特性的影响

IGBT模块一般采用多芯片并联的方式进行封装,但由于模块参数、驱动控制等差异,模块内部存在电流分布不均衡的问题。相比于稳态电流分布,瞬态电流分布的影响因素众多,是研究的热点。针对IGBT的芯片参数开展了模块内部各支路瞬态电流分布特性的研究。通过建立IGBT芯片模型及芯片并联的瞬态电路分析模型,计算单一芯片参数与多种芯片参数作用下IGBT模块的瞬态电流分布,提出新的适用于芯片支路瞬态均流分析的评价指标,得到了IGBT芯片参数对并联瞬态均流影响的规律。研究结果表明阈值电压、跨导和栅极电阻是对瞬态均流影响最大的3个芯片参数,且需要关注阈值电压与跨导的共同影响。研究结果对IGBT的芯片筛选及并联后的瞬态均流计算具有指导意义。     

功率MOSFET参数测试仪的设计

功率MOSFET参数测试仪是用来测试功率MOSFET电特性参数的仪器设备（如阈值电压、跨导等）。以单片机为核心,介绍功率MOSFET参数测试仪的原理、设计及实现,设计了电特性参数测试的具体电路,编写了测试控制程序,通过对设计出的测试仪系统进行实验和调试,可以准确测量功率MOSFET的阈值电压、跨导、栅源漏电流、零栅压漏极电流及耐压。     

一种新型开关电源的并联均流技术的实现方法

随着分布式电源的发展,开关电源并联技术的重要性日益突出。研制大功率、高性能的开关电源是人们不断努力和追求的目标。文中介绍了电源模块并联供电的优势,并论述了几种并联均流电路的工作过程及优缺点,介绍了一种廉价的基于UC3875的并联技术的实现方法。     

Analysis and control design of paralleled DC/DC converters withcurrent sharing

This paper presents a general small-signal stability analysis of paralleled power converter systems. The framework specializes to include both the “democratic” and “master-slave” current-sharing schemes. Design examples illustrate how to obtain stable current sharing. The authors show how paralleled power converters can become unstable (even when active current sharing is absent) and discuss the influence of the number of converters paralleled     

Characteristics Measurements of HTS Tape with Parallel HTS Tapes

Many high temperature superconducting (HTS) tape manufactures make an effort to reduce the transport current loss of HTS tapes. The knowledge of critical current and self-field in an HTS tape is very useful to compute the transport current losses. The spatial distribution and magnitude of self-field are variable due to the neighboring materials. In this paper, the critical currents and the transport current losses of BSCCO and YBCO tapes with paralleled magnetic material (Ni tape) and/or diamagnetic material (BSCCO tape) are experimentally investigated to improve the AC loss properties. The critical currents of HTS tapes with paralleled Ni tape are slightly decreased and the transport current losses are markedly increased. However, the critical currents and transport current losses of HTS tapes with paralleled BSCCO tape have not current carrying are more improved than single HTS tape.     

晶闸管并联静动态均流原理的教学

晶闸管的并联均流是"电力电子技术"课程的一个内容,大多数教科书对该部分的介绍都以定性分析为主,使学生难以建立完整的概念.本文根据目前电力电子技术的发展,从影响晶闸管并联均流的因素,如通态压降、开关时间、器件温度和母线配置等,到实现均流的技术和方法,系统阐述了晶闸管并联的静动态均流特性,从而弥补了现有教科书中的不足.     

固态雷达发射机多路电源的并联均流设计

大功率电源系统的发展趋势是实现电源组件模块化,再通过多个模块的并联以满足负载功率的要求。模块化电源的并联运行是扩大电源系统容量和提高固态雷达发射机可靠性的重要手段,要实现电源模块并联运行的可靠性,各电源模块应具有良好的均流特性。文中通过对不同并联方法的分析比较,介绍了最大电流法自动均流控制电路的工作原理及设计,并由试验给出均流效果。     

应用于并行直流转换电源的均流控制芯片设计

为实现并行直流转换电源系统中转换器电流的均衡分布,降低转换器承受的电、热应力,提高系统可靠性,给出一种采用自动主从控制策略的均流方案,并给出了方案实现的关键部件--均流控制芯片的设计.设计中采用电流反馈环路对输出电压进行调整,降低了PCB板级寄生效应对调整信号的影响;并提出一种启动控制电路用以改善系统的启动时序,加速了启动阶段的电流均衡过程.芯片采用1.5μm BCD(Bipolar-CMOS-DMOS)工艺设计实现,面积为3.6mm2.应用该芯片构成了一个由两个直流转换器组成,具有12V/3A输出能力的并行电源系统.测试结果表明,该并行电源系统满负载时均流误差小于1%.     

Monitoring of paralleled IGBT/diode modules

A method is presented to monitor the state of a converter with an unlimited number of paralleled insulated gate bipolar transistor (IGBT)/diode modules with individual gate drives. The monitoring functions can be implemented without extra signal processing or load-side components. The method is based on the active gate-controlled current balancing (CB) principle. This principle is reviewed in the first part of this paper, and the necessary supplements to implement the monitoring functions are shown. In the second part, experimental measurements are shown. This new control method allows monitoring the state of a converter and balancing the losses and current sharing between paralleled power devices, without the need to match the devices nor the gate drives. Thus, the overall reliability can be increased without increasing the costs. Since no matching of the devices is needed, the handling and logistic costs can be significantly reduced. IGBT/diode modules for standard paralleling are selected, and only modules of the same class can be paralleled without excessive derating. The presented method allows switching off one of the paralleled branches in the case of parameter degradation and to keep the converter operating at a lower power     

大功率整流模块中的开关管并联工作分析

分析了大功率整流模块中并联开关管的静态和动态工作特性,指出并讨论了设计中需要解决的一些问题.给出了容量为230V/25A、开关频率为70kHz的电力充电模块中并联的IGBT的电流波形.     

A novel communication strategy for decentralized control of paralleled multi-inverter systems

A new communication strategy for decentralized control of paralleled multi-inverter systems is introduced in this paper. The proposed strategy utilizes the common mode signal's circuit in the paralleled system as a channel of communication between individual inverters. Source voltage synchronization for paralleled inverters is presented to demonstrate its effectiveness. One inverter module acts as a source and a synchronized signal is sent by means of frequency modulation in this channel to all other modules via the common mode current. Each module will then receive and transform the signal to be used as a synchronized voltage command for individual inverters. The approach enables synchronization in the paralleled multi-inverter system and the method is not affected by external factors such as load change, output voltage variation, and different types of loads. The principle of operation, performance of the proposed strategy, as well as the experimental evaluation with three single-phase paralleled inverters are discussed and presented in this paper.     

Electro-thermal simulation of current sharing in silicon and silicon carbide power modules under short circuit condition of types I and II

Current sharing during short circuit events of types I and II has been investigated by electro-thermal compact simulation of semiconductor devices paralleled in a 650 V power module. The response of silicon IGBTs has been compared to that of silicon carbide MOSFETs. The study of current unbalance due to symmetrical and asymmetrical interconnect topologies has been followed by isothermal and full electro-thermal simulation of the power modules. It has been shown that replacing in the simulation the active devices within the module by resistors leads to misleading results, because the current unbalance under short circuit conditions is mainly due to the difference in the gate-source/gate-emitter voltage among the individual paralleled devices. Finally, it has been demonstrated that in the investigated power modules, self-heating contributes to the mitigation of current unbalance.