IGBT加速老化实验研究

绝缘栅双极型晶体管(IGBT)功率模块作为电力电子设备的关键器件被广泛应用,其工作寿命与可靠性将影响到整个装置或系统的正常运行,对于IGBT可靠性研究具有重要意义。IGBT加速老化实验是研究IGBT可靠性问题的重要方法,其在不改变产品故障机制的前提下,提高实验应力,加速产品的故障进程,能有效缩短实验时间,节约成本。分析了IGBT的失效机理,依据IEC标准,设计了IGBT直流功率循环加速老化实验,自行设计搭建了IGBT加速老化实验系统,能够完成器件的老化以及监测老化前后器件参数的变化。研究成果为IGBT模块的可靠性研究以及健康状态评估提供了重要依据。     

大功率IGBT模块软关断短路保护策略

大功率绝缘栅双极晶体管(IGBT)模块在电力电子设备中的运用越来越广泛,其对驱动器的性能要求也越来越高。IGBT可以承受短路的时间非常短,短路时最大电流远远超过额定值,单位时间功耗也远远高于正常工作状态,且直接关断IGBT会产生非常高的关断尖峰电压。提出缓慢降低IGBT门级电压的软关断策略,驱动器检测到IGBT短路后用0 V驱动电压立即执行软关断动作,当电流降到一定值后再使用负压正常关断。此策略可以使驱动器更早地采取保护措施,限制IGBT短路电流,减小IGBT短路功耗并控制关断尖峰电压。硬关断策略短路保护实验和软关断策略短路保护实验的结果对比验证了软关断策略的优势。     

基于IGBT芯片疲劳机理的关断时间可靠性模型

基于绝缘栅双极型晶体管(IGBT)芯片疲劳机理,提出采用关断时间对IGBT健康状态进行监控的可靠性评估方法。采用理论分析与解析描述相结合的方法,建立了IGBT关断电流下降时间模型,进而通过研究IGBT关断时间特征量疲劳机理,建立了IGBT关断时间可靠性评估模型。仿真和实验验证了该模型的正确性与准确性。通过该模型可对IGBT的健康状况进行准确评估。     

4 500 V沟槽栅IGBT芯片的设计与研制

为提升IGBT单芯片的电流密度,掌握高压沟槽栅IGBT技术,进行4500 V沟槽栅IGBT芯片的研制。使用TCAD仿真软件,对4500 V沟槽栅IGBT的衬底材料、载流子储存层设计、沟槽宽度、沟槽深度、假栅结构等方面进行研究和仿真分析,明确各方面设计与芯片性能的关系。根据总体设计目标,确定相应的芯片结构和工艺参数,并对4500 V沟槽栅IGBT芯片进行流片验证。验证结果显示：4500 V沟槽栅IGBT芯片的测试结果符合设计预期,芯片的额定电流、导通压降、开通损耗和关断损耗等关键参数相比平面栅IGBT芯片有明显优化。     

4 500 V沟槽栅IGBT芯片的设计与研制

为提升IGBT单芯片的电流密度,掌握高压沟槽栅IGBT技术,进行4500 V沟槽栅IGBT芯片的研制。使用TCAD仿真软件,对4500 V沟槽栅IGBT的衬底材料、载流子储存层设计、沟槽宽度、沟槽深度、假栅结构等方面进行研究和仿真分析,明确各方面设计与芯片性能的关系。根据总体设计目标,确定相应的芯片结构和工艺参数,并对4500 V沟槽栅IGBT芯片进行流片验证。验证结果显示：4500 V沟槽栅IGBT芯片的测试结果符合设计预期,芯片的额定电流、导通压降、开通损耗和关断损耗等关键参数相比平面栅IGBT芯片有明显优化。     

PSPICE和Matlab在IGBT动态仿真中应用

简要分析了目前常用的电力电子仿真软件PSPICE(Simulation Program with IC Emphasis)和Matlab的主要性能特点及在电力电子仿真中的适用程度。绝缘栅双极型晶体管IGBT(Insulated Gate Bipolar Transistor)开关回路在关断瞬间由于感性负载的作用常会伴随着擎住效应,对IGBT器件本身会造成严重的损伤,因此必须在IGBT器件两端并联缓冲电路．以实现对器件的过压保护。缓冲电路的拓扑结构有多种．过压保护的效果也不一样。应用以上两种仿真软件对IGBT开关回路进行动态仿真研究．比较并分析了两种缓冲电路在IGBT关断瞬间的不同过压保护效果。并且说明了PSPICE和Matlab仿真结果的差异及其原因。     

一种基于调节缓冲电容的IGBT热管理方法

针对结温波动加快绝缘栅双极型晶体管(IGBT)老化失效的问题,提出一种基于调节缓冲电容改变IGBT关断轨迹的热管理方法。依据IGBT寿命模型,通过关断轨迹调节关断损耗大小以平滑结温波动的方法能提高IGBT使用寿命。与现有的热管理方法相比,该方法具有对主电路影响小、实现简单等优点。首先,阐述热管理电路的工作原理,分析缓冲电路对IGBT关断损耗的影响。然后,建立IGBT损耗计算模型,归纳关断轨迹热管理调节能力的评估方法,以1.2 MW直驱风机系统为例,关断轨迹热管理可以平滑20%额定功率的负载变化造成的结温波动。最后,对该热管理方法进行小功率的实验验证。     

基于EXB 841的IGBT驱动电路设计及优化

介绍了绝缘栅双极型晶体管IGBT(Insulated Gate Bipolar Transistor)器件驱动电路设计的一般要求．对EXB841芯片的工作过程作了深入的分析,研究了EXB841对IGBT的开通和关断以及过流保护的原理．指出了用EXB841直接驱动IGBT时存在的问题和不足,主要是过流保护的阀值太高、关断不可靠及在软关断时没有对外部输入信号进行封锁。同时,提出了针对这些不足在设计驱动电路时应当采取的几种有效方法最后,运用EXB841及其他器件设计和优化了一个IGBT的驱动电路．该驱动电路通过电力电子仿真软件PSPICE(Simulation Program with IC Emphasis)仿真和试验证明能够有效地对IGBT器件进行驱动和过电流保护。     

基于循环神经网络的IGBT退化特性参数研究

绝缘栅双极型晶体管(IGBT)在应用中存在器件退化问题,分析了采用数据驱动技术实现退化特性参数识别的合理性,并提出了一种基于循环神经网络的分析方法.该方法通过选择集电极-发射极关断峰值电压作为退化特性参数,采用循环神经网络建模,实现退化特征参数的预测.采用了NASA PCoE研究中心提供的IGBT加速老化数据集,进行数据预处理,得到IGBT关断尖峰电压序列,并划分出训练集和测试集,其中训练集用于训练循环神经网络,测试集用于评估方法的准确性,实验结果表明循环网络相比于经典机器学习算法具有更高的预测精度.     

不间断电源中的IGBT关断过电压抑制

由于电路中杂散电感及绝缘栅双极型晶体管(IGBT)反并联二极管浪涌电压的影响,IGBT在关断过程中会产生过电压尖峰。分析了IGBT关断过程,提出了一种由过电压采样电路和动态过电压抑制电路构成的有源IGBT过电压抑制电路方案,并对该方案进行仿真及实验,结果表明,该过电压抑制电路能有效抑制IGBT过电压产生,防止IGBT过电压损坏,提高了UPS电源的可靠性和工作效率。     

IGBT模块直接串联电压均衡驱动控制技术

高压绝缘栅双极型晶体管(IGBT)模块直接串联技术是实现柔性直流输电、高压直流断路器等高压大功率控制设备的一个重要基础,其中最难解决的是串联IGBT模块之间的电压均衡问题。文中分析了电压不平衡的机制,得出了实现电压均衡的关键在于解决断态电压不平衡和关断电压不平衡问题,门极侧均衡控制方法是较好的解决手段。对基于有源电压控制技术的驱动设计和基于延时补偿的控制策略进行了探讨,并分别采用在有源区对关断波形进行跟随控制和补偿IGBT器件间关断延时的方法,有效实现了串联器件的电压均衡。最后,通过6只3 300V/1 200AIGBT模块直接串联的阀段脉冲和基于该阀段的三相换流阀运行测试,对这两种方法进行了验证,所述方法获得了较好的电压均衡效果。     

高速集电极沟槽绝缘栅双极晶体管

在前期高速绝缘栅双极晶体管(IGBT)的基础上提出一种高速集电极沟槽绝缘栅双极晶体管(CT-IGBT)。该器件沟槽集电极与漂移区的内建电势差感应形成电子沟道而加快关断速度,且集电极沟槽具有不同于传统电场截止层(FS)的电场截止机制,并引入低浓度N型层以降低集电极沟槽对空穴注入的抑制作用。硅基材料有限元仿真结果表明,新结构CT-IGBT的关断下降时间比传统沟槽FS-IGBT少49%,且前者耐受的雪崩能量比后者高32%。因此,新结构CT-IGBT具有比FS-IGBT更优越的关断速度和强度,可应用于大功率高速电力电子系统。     

Characteristics and utilization of a new class of low on-resistanceMOS-gated power device

A new class of MOS-gated power semiconductor devices Cool MOS (Cool MOS is a trademark of Infineon Technologies, Germany) has been introduced with a supreme conducting characteristic that overcomes the high on-state resistance limitations of high-voltage power MOSFETs. From the application point of view, a very frequently asked question immediately arises: does this device behave like a MOSFET or an insulated gate bipolar transistor (IGBT)? The goal of this paper is to compare and contrast the major similarities and differences between this device and the traditional MOSFET and IGBT. In this paper, the new device is fully characterized for its: (1) conduction characteristics; (2) switching voltage, current, and energy characteristics; (3) gate drive resistance effects; (4) output capacitance; and (5) reverse-bias safe operating areas. Experimental results indicate that the conduction characteristics of the new device are similar to the MOSFET but with much smaller on-resistance for the same chip and package size. The switching characteristics of the Cool MOS are also similar to the MOSFET in that they have fast switching speeds and do not have a current tail at turn-off. However, the effect of the gate drive resistance on the turn-off voltage rate of rise (dv/dt) is more like an IGBT. In other words, a very large gate drive resistance is required to have a significant change on dv/dt, resulting in a large turn-off delay. Overall, the device was found to behave more like a power MOSFET than like an IGBT     

智能化IGBT驱动电路研究

研究并设计了一种基于复杂可编程逻辑器件(CPLD)的智能化IGBT驱动电路.该电路由CPLD实现各种控制、保护逻辑.驱动电路的高、低电平驱动方式可通过改写CPLD中VHDL源代码来实现.同时,该电路可以选择两路直接驱动和桥臂互补驱动两种工作模式.电路具有开通盲区设置,死区时间设置功能,短路保护运用软降栅压结合软关断技术,软降栅压时间,软关断斜率可通过外接电路自由整定.电路本身自带隔离驱动电源.试验证明该电路具有良好的驱动及保护能力.     

EMTP modeling of IGBT dynamic performance for power dissipationestimation

A new approach to the modeling of insulated gate bipolar transistors (IGBTs) for electromagnetic transients program (EMTP) simulation is developed. Other commercially available simulators, such as PSPICE, model the devices on an exact semiconductor physics basis. They suffer from large amounts of CPU time for sinewave pulsewidth modulation (PWM) inverter applications which require a complete cycle simulation at fundamental frequency with a small time step to cover the details of IGBT switching transients. This approach uses a curve-fitting method, combined with the point-by-point user-defined function available in EMTP, to model the dynamic characteristics of IGBTs. Since there is no device physics modeling required, this simulation is much faster than the conventional approach. The proposed method is applicable to both static and dynamic modeling, on a cycle-by-cycle basis, which is important for dynamic power dissipation and thermal analysis. The simulation includes IGBT turn-on and turn-off transients, IGBT saturation, free-wheeling diode forward voltage and reverse recovery characteristics. The simulation results are verified by comparison with experimental measured data. Measurements show a close agreement with simulations     

Double-stage gate drive circuit for parallel connected IGBT modules

Solid state modulators are increasingly being used in pulsed power applications. In these applications IGBT modules must often be connected in parallel due to their limited power capacity. In a previous paper, we introduced a control method for balancing the currents in the IGBTs. In this paper, we investigate techniques to minimize the modules' rise and fall times, which can positively impact the modulator's output pulse parameters, which in turn must meet the application's specifications. Further, a reduction in rise and fall times lowers switching losses and thus increases the modulator's efficiency. To reduce the voltage rise time of the pulse without increasing the maximal over-voltage of the parallel IGBTs we have investigated a double-stage gate driver with protection circuits to avoid over-voltages and over-currents. Additionally voltage edge detection has been implemented to improve current balancing. Our measurement results reveal the dependency of the rise-time and turnoff losses on the design parameters of the gate drive. We show that our design achieves a 62% reduction in the turn-off rise time, and a 32% reduction in the turn-off losses.     

Degradation state analysis of the IGBT module based on apparent junction temperature

The multi-chip parallel insulated gate bipolar transistor (IGBT) is the core device in large-capacity power electronic equipment, but its operational reliability is of considerable concern to industry. The application of IGBT online degradation state analysis technology can be benefcial to the improvement of system reliability. The failure mechanism of IGBT devices is discussed in this paper, and a technique for analyzing the degradation state of IGBT based on apparent junction temperature is proposed. First, the distortion consistency of the voltage rise time in various failures is discussed, and the junction temperature dependence of the voltage rise time is then demonstrated. Subsequently, an apparent junction temperature model based on the voltage rise time is established (the ftting accuracy is as high as 94.3%). From the high-frequency model in the switching process of the device, an online extraction technology of key parameters (e.g., voltage rise time) is developed. Finally, an experimental platform for IGBT degradation state estimation is established, and the feasibility of IGBT degradation state estimation based on apparent junction temperature is proved, especially the degradation of bonding-wire and the gate-oxide-layer. The experimental results show that the proposed IGBT degradation state estimation technique based on apparent junction temperature is a reliable online estimation method with non-contact, high accuracy, and comprehensiveness.     

Degradation state analysis of the IGBT module based on apparent junction temperature

The multi-chip parallel insulated gate bipolar transistor (IGBT) is the core device in large-capacity power electronic equipment, but its operational reliability is of considerable concern to industry. The application of IGBT online degradation state analysis technology can be benefcial to the improvement of system reliability. The failure mechanism of IGBT devices is discussed in this paper, and a technique for analyzing the degradation state of IGBT based on apparent junction temperature is proposed. First, the distortion consistency of the voltage rise time in various failures is discussed, and the junction temperature dependence of the voltage rise time is then demonstrated. Subsequently, an apparent junction temperature model based on the voltage rise time is established (the ftting accuracy is as high as 94.3%). From the high-frequency model in the switching process of the device, an online extraction technology of key parameters (e.g., voltage rise time) is developed. Finally, an experimental platform for IGBT degradation state estimation is established, and the feasibility of IGBT degradation state estimation based on apparent junction temperature is proved, especially the degradation of bonding-wire and the gate-oxide-layer. The experimental results show that the proposed IGBT degradation state estimation technique based on apparent junction temperature is a reliable online estimation method with non-contact, high accuracy, and comprehensiveness.