Rated overload Characteristics of IGBTs for low-voltage and high-voltage devices

By a vertical shrink of the nonpunchthrough insulated gate bipolar transistor (NPT IGBT) to a structure with a thin n-base and a low-doped field stop layer a new IGBT can be realized with drastically reduced overall losses. In particular, the combination of the field stop concept with the trench transistor cell results in an almost ideal carrier concentration for a device with minimum on-state voltage and lowest switching losses. This concept has been developed for IGBTs and diodes from 600 V up to 6.5 kV. While the tradeoff behavior (on-state voltage V/sub CEsat/ or V/sub F/ to tail charge) and the overall ruggedness (short circuit, positive temperature coefficient in V/sub CEsat/, temperature independence in tail charge, etc.) is independent of voltage and current ratings the switching characteristics of the lower voltage parts (blocking voltage V/sub Br/<2 kV) is different in handling to the high-voltage transistors (V/sub Br/>2kV). With the HE-EMCON diode and the new field stop NPT IGBT up to 1700 V there is almost no limitation in the switching behavior, however, there are some considerations-a certain value in the external gate resistor has to be taken. High-voltage parts usually have lower current density compared to low-voltage transistors so that the "dynamic" electrical field strength is more critical in high-voltage diodes and IGBTs.     

Characterization of high power IGBTs with sinewave current

The IGBTs characteristics are examined in a single-pulse series resonant circuit under controlled temperature. The aim being to reach the highest possible switching frequency for IGBTs with ratings suitable for industrial use, it is found that both switching energy and on-state losses must be measured, as on-state losses also vary with frequency. It is also found that IGBTs, though having the same datasheet rating, can have properties depending on the manufacturers philosophy giving them totally different behavior at high frequencies. The time needed for the conductivity modulation mechanism to get into action is crucial, giving advantages to devices from manufacturers using low carrier lifetime and high bipolar emitter efficiency, such as Toshiba. The same datasheet ratings both in current, voltage and switching speed can be achieved with high carrier lifetime and low bipolar emitter efficiency, like Siemens devices, which in the resonant circuit will have their advantages under other modes of operation than Toshiba     

Experimental modeling of high-voltage corona discharge using design of experiments

Many studies, both experimental and numerical, were devoted to the electric current of corona discharge and some mathematical models were proposed to express it. As it depends on several parameters, it is difficult to find a theoretical or an experimental formula, which considers all the factors. So we opted for the methodology of experimental designs, also called Tagushi’s methodology, which represents a powerful tool generally employed when the process has many factors to consider. The objective of this paper is to model current using this experimental methodology. The factors considered were geometrical factors (interelectrode interval, surface of the grounded plane electrode, curvature radius of the point electrode), climatic factors (temperature and relative humidity), and applied high voltage. Results of experiments made it possible to obtain mathematical models and to analyse the interactions between all factors.     

IGBT的低温特性及计算机仿真

研究了非穿通型(Non-PunchThrough,NPTI)GBT在77～300K之间的暂稳态特性。研究表明,低温环境下NPT-IGBT的通态压降、寄生PNP晶体管电流增益和关断时间均有减小,门槛电压和跨导增加。在总结并改进硅材料主要参数在低温区的温度模型基础上,分析了NPT-IGBT低温特性的物理机制,并实现其关键参数随温度变化趋势的计算机仿真,仿真结果与实验数据取得一致。     

Static and dynamic behavior of paralleled IGBTs

Problems associated with power device characteristics when power devices are connected in parallel, such as thermal stability and balanced switching behavior, can be solved by using insulated gate bipolar transistors (IGBTs). The author deals with parallel IGBT behaviors analyzing both static and dynamic characteristics. The influence of heatsink mounting, layout, and drive circuit are described in order to demonstrate the best way to make IGBTs parallel for optimum performance. In addition, the major advantages of the ISOTOP package are shown     

IGBT并联特性的研究与仿真

为满足大功率逆变器的设计需要,针对功率器件IGBT并联使用时的工作特性进行了研究.主要分析了驱动电路和器件各参数不理想时对IGBT并联工作产生的不利影响,重点研究了电流分配、安全工作范围、散热以及寄生振荡等关键问题.最后结合仿真结果,提出保证多个IGBT并联工作的合理建议.     

面向中高压智能配电网的电力电子变压器建模方法与控制策略研究

分析了传统电力电子变压器建模及控制策略的国内外研究现状,以及面向中高压配电网的电力电子变压器建模及控制策略的局限性。在此基础上,基于谐振变换器的工作特点,提出了面向中高压电网的电力电子变压器统一降阶建模方法及单级控制策略。该策略结构简单,控制能力强。相比于传统电力电子变压器的建模方法与控制策略,所提出的控制策略有效地利用了高频隔离型变换器的工作特点,将高频隔离型变换器与前端级联型变换器结合为一体,简化了控制系统,使其不会随着模块数增加而变得复杂。最后在PSCAD仿真环境中验证了10 kV电力电子变压器的拓扑及其控制策略的可行性。     

通用型IGBT变频电源的研制

提出的ＩＧＢＴ通用变频电源,已完成了实用化和系列化。论述了该装置的主电路,控制系统结构,以及擎住效应,变压器偏磁的抑制方法。给出了控制电路、驱动电路、保护电路的设计原则和单相４ｋＷ变频电源的主要技术指标。     

大功率IGBT并联运行时均流问题研究

绝缘栅双极晶体管(IGBT)的并联运行能够承受更高的负载电流,但同时也带来了动、静态的均流问题．从理论上分析认为导致动、静态不均流的主要因素是器件的饱和导通压降Uce(sat)不同引起的。提出了IGBT并联均流的措施,指出了构建IGBT并联电路的要点,以及应用栅极电阻补偿法进行均流,仿真分析验证了提出的方法措施可行。     

Voltage-balancing method for IGBTs connected in series

This paper presents a new method for balancing voltages of series-connected insulated gate bipolar transistors (IGBTs). This method can be implemented only by adding simple circuits to the gate drive system of the IGBTs, and its effect of balancing the IGBT's collector-emitter voltages during the switching transients is remarkable. This principal strategy and experimental results with series-connected IGBTs are first described. After that, further experimental results are shown from the switching tests of four 2.5-kV flat-packaged IGBTs connected in series. Through the switching tests, superior characteristics of the proposed method have been confirmed.     

压接型IGBT器件内部压力分布

压接型IGBT器件内部各组件直接堆叠在一起,通过外部压力使得各组件间保持良好的机械与电气接触,进而引入一定比例的接触电阻和接触热阻,所以器件内部的压力分布不仅影响器件内部的电流分布和温度分布,还将严重影响器件的可靠性。基于压接型IGBT器件的有限元计算模型和特殊的应用工况,研究压接型IGBT器件内部的压力分布情况,重点探讨器件内部各组件加工误差与内部的布局方式对器件内部压力分布的影响。通过压力夹具和压力纸等进行压接型IGBT器件内部压力分布的实验,实验结果不仅验证了有限元模型和边界条件的正确性,还表明外部压力加载对器件内部压力分布的影响。     

IGBT串联均压方法综述

绝缘栅双极性晶体管IGBT(insulated gate bipolar transistor)在高电压场合应用时需串联使用满足电压需求。由于器件内部的性能差异和外围电路参数不一致等,引起IGBT模块之间电压不均衡问题,威胁其运行安全。综述了国内外IGBT串联均压方法的发展及其研究现状。根据均压方法机理的不同,将IGBT串联均压方法分为被动均压方法和主动均压方法两种,进一步将主动均压方法归纳为无源控制方法和有源控制方法两类。根据各类方法的基本电路拓扑分析了均压原理,梳理了不同方法在电路拓扑、参数选择和控制策略等方面的优化和最新进展。通过均压效果、附加损耗和可靠性等多方面对不同均压方法进行对比,被动均压方法拓扑简单不需外加控制电路更适合在低频应用场合,在高频应用场合中,准有源栅极控制法以单驱动与无源器件相结合的方式,具有良好的发展前景。最后对IGBT串联均压方法进行了展望。     

SiC MOSFETs与Si IGBTs的性能对比研究

通过采用双脉冲测试方法,以具有相同电流额定值的SiC MOSFET CMF10120D(1 200V/24A)和Si IGBT IKW25T120(1 200 V/25 A)作为样本,在相同测试条件下研究了两种器件的动态特性、反并联二极管的反向恢复特性和开关损耗。研究发现,SiC MOSFET的开关速度快,开关损耗仅为Si IGBT的69%。最后,利用IPOSIM对两种器件应用于三相逆变器中的结温进行对比研究。结果表明,在输出频率为50 Hz时,Si IGBT的最大结温为166℃,已超过允许的150℃,结温波动为37℃,而SiC MOSFET的最大结温仅为105℃,结温波动仅为19℃;反并联二极管的结温波动基本相同,但Si IGBT反并联二极管的最大结温要高出26℃。因而,在大功率、高温电力电子变换器的应用中,SiC MOSFET更具优越性。     

基于IGBT串联运行的动态均压研究

绝缘栅双极晶体管IGBT(Insulated Gate Bipolar Transistor)串联运行易于实现IGBT的扩容,但同时也带来了不均压的问题。设计了以L,R为感性负载的实验电路,采用仿真软件PSpiee仿真分析出IGBT串联运行时动态不均压原因是吸收电路参数不一致、门极驱动信号延时不同、门极驱动电路参数不一致引起的。并提出了IGBT串联运行动态均压措施(选同型号IGBT、吸收电路参数与结构一致、门极驱动信号同步、门极电路参数一致)。     

自适应IGBT串联均压电路设计

单个绝缘栅双极型晶体管(IGBT)由于耐压的限制,在节能和改善电网电能质量、柔性直流输电、高压变频器、静止同步补偿器,以及有源滤波器等高压大功率电能变换场合还不能满足需求,而串联使用是一种较好的解决方案。文中提出了一种适用于串联IGBT的自适应动态均压方案,详细分析了其工作原理,并通过仿真和实际电路对其进行了验证。在此基础上研制了一套由4组5只IGBT直接串联桥臂组成的全桥逆变演示系统,串联回路中的每只耐压1 200V的IGBT稳定工作在900V,其电压利用效率达到了75%,具有较高的实用价值。     

大功率IGBT模块并联均流问题研究

介绍了IGBT扩容的并联方法,分析了导致IGBT模块并联运行时不均流的各种因素,提出了相应的解决措施,并进行了仿真分析和实验验证。     

采用电压箝位控制实现串联IGBT的动态均压

IGBT串联应用时面临的最大难题是动态均压。本文研究了电压箝位控制方法,它将IGBT的集?射电压变化快速反馈至门极,改变门极驱动电压的大小,从而将集?射电压实时箝位于控制阈值之内,实现串联IGBT的动态均压。本文通过2个和8个IGBT串联的实验,验证了该方法的有效性。     

基于IGBT串联技术的高压优性能开关

IGBT串联组合应用可以迅速满足硬开关应用场合中的电压等级要求,一个简易可靠的辅助电路可以有效解决串联IGBT正常运行中的电压不均衡问题。应用OrCAD／PSpice仿真软件,对比分析了单管CM600HA-24H（600A／1200V）和两个CM600HA-12H（600A／600V）的串联组合的开关表现。仿真结果表明,和单管IGBT相比较,IGBT串联组合在能量损耗、集电极过电压以及开关频率等方面有着明显的优势,从理论上证明了IGBT串联组合可以有着更好的开关表现,对实践有一定的指导意义。     

计及内部材料疲劳的压接型IGBT器件 可靠性建模与分析

大功率压接型IGBT器件更适合柔性直流输电装备应用工况,必然对压接型绝缘栅极晶体管（IGBT）器件可靠性评估提出要求。提出计及内部材料疲劳的压接型IGBT器件可靠性建模方法,首先,建立单芯片压接型IGBT器件电-热-机械多物理场仿真模型,通过实验验证IGBT仿真模型的有效性;其次,考虑器件内部各层材料的疲劳寿命,建立单芯片压接型IGBT器件可靠性模型,分析了单芯片器件各层材料薄弱点;最后针对多芯片压接型IGBT器件实际结构,建立多芯片压接型IGBT器件多物理场仿真模型,分析器件应力分布,并对各芯片及多芯片器件故障率进行计算。结果表明,压接型IGBT器件内部的温度、von Mises 应力分布不均,最大值分别位于IGBT芯片和发射极钼层接触的轮廓线边缘;多芯片器件内应力分布不均会导致各芯片可靠性有所差异,边角位置处芯片表面应力最大,可靠性最低。