A study on IGBT junction temperature (Tj) online estimation using gate-emitter voltage (Vge) at turn-off

A novel method is presented for online estimation of the junction temperature (Tj) of semiconductor chips in IGBT modules, based on evaluating the gate-emitter voltage (Vge) during the IGBT switch off process. It is shown that the Miller plateau width (in the Vge waveform) depend linearly on the junction temperature of the IGBT chips. Hence, a method can be proposed for estimating the junction temperature even during converter operation – without the need of additional thermal sensors or complex Rth network models. A measurement circuit was implemented at gate level to measure the involved time duration and its functionality was demonstrated for different types of IGBT modules. A model has been proposed to extract Tj from Vge measurements. Finally, an IGBT module with semiconductor chips at two different temperatures has been measured using Vge method and this method was found to provide the average junction temperature of all the semiconductor chips.     

Investigations on junction temperature estimation based on junction voltage measurements

Reliability and ageing tests on power semiconductor devices require estimation of junction temperatures in order to control thermal stresses and monitor failure criteria. For this purpose, thermo-electrical parameters, such as voltage forward drop dependence with temperature are usually carried out in low injection level. Nevertheless, it is still difficult to evaluate the limits of such exploitation. An analytical model has been developed and validated by experimental measurements in order to evaluate self-heating effects and to understand high temperature effects. This model should also allow to highlight the role of some physical parameters in the voltage–temperature dependence and to clarify such thermal calibration.     

高空飞行器供油驱动系统IGBT模块结温特性研究

对高空飞行器供油驱动系统在特定负载状态下的IGBT模块结温特性进行研究。高空飞行器对供油驱动系统的高功率密度要求高及环境散热条件差的状况,使得其关键部件IGBT模块在功率裕量与结温控制方面更为严格。根据负载特性精确计算结温,对于在特定散热条件下系统的可靠运行非常重要。运用非稳态导热的Foster集总参数法,分析IGBT模块点热源特性及其他热源对计算影响,建立一种含校正系数的热网络模型,并在短时脉冲过载及输出低频两种特有状态下,对IGBT模块的结温特性进行分析。通过对高空飞行器飞行过程中IGBT模块结温特性的计算,结合仿真软件Semisel的对比分析,验证了建模和分析本文所提方法的有效性。     

晶闸管的瞬态热阻抗及其结温温升的研究

系统地阐述了晶闸管的瞬态热阻抗 ,针对晶闸管承受不同的功率脉冲 ,利用不同的计算方法计算瞬态热阻抗值 ,从而确定结温温升 ,并比较了它们的原理、精度及其应用范围。特别是利用了一种新的瞬态热阻抗计算模型 ,当晶闸管承受持续时间极短且周期、占空比均变化的任意波形功率脉冲时 ,它能够比较精确地分析晶闸管的热特性 ,计算半导体结的最大温升     

The effect of electro-thermal parameters on IGBT junction temperature with the aging of module

This paper presents the effect of the change of electro-thermal parameters on IGBT junction temperature with module aging. Five IGBT modules are subjected to advance power thermal cycling, and IGBT I–V characterization, switching loss, and transient thermal impedance curve are measured every 1000 power thermal cycles. Then, electro-thermal models of IGBT module under power thermal cycles were built by change electro-thermal parameters, and the influence of various parameters of the electro-thermal model on the junction temperature was researched respectively. Experimental results demonstrate that IGBT collector-emitter voltage, switching loss and thermal resistance increase more quickly with the aging process of module. Simulation results indicate that the variations of electro-thermal parameters have crucial influences on the IGBT junction temperature. After 6000 power thermal cycles, the IGBT steady state junction temperature mean and variation are increased 1.97 K and 0.1656 K over its initial value, respectively. The relative temperature rise is 38.10% and relative temperature variation is 15.08% after 6000 power thermal cycles. The rise in switching loss increases both the steady state junction temperature mean and variation. The change of thermal impedance has great influence on the steady state junction temperature mean, but has little effect on steady state junction temperature variation.     

Electrical measurement of the junction temperature and thermal resistance of HBTs

A simple method is proposed to derive the junction temperature and the bias- and temperature-dependent thermal resistance of heterojunction bipolar transistors (HBTs) using a radio frequency (RF) signal. The method exploits the thermal dependence of the current gain of a transistor whose dissipated power is modified by applying an RF signal. The new method is used to derive the junction temperature and thermal resistance of a power HBT. The results are compared with state-of-the-art techniques.     

Lifetime estimation for IGBT modules in wind turbine power converter system considering ambient temperature

Power semiconductors in the wind turbine power converter system suffer from two-scale thermal loadings, the fundamental frequency thermal cycling caused by the output frequency of converter and the low frequency thermal cycling due to the variation of long-term wind speed. These two-scale thermal loadings introduce different consumed lifetimes. Accurate lifetime estimation in the wind power application is desired for reliability prediction and health management. This paper adopts the Bayerer lifetime model to evaluate the consumed lifetime of power semiconductors in wind power converter systems based on a numerical junction temperature calculation method. Lifetime estimation can be improved by taking into account the ambient temperature. Studies show that fluctuations of the ambient temperature increase the consumed lifetime due to the low frequency thermal cycling, but have little effect on the consumed lifetime due to the fundamental frequency thermal cycling. Our results also show that the consumed lifetime due to fundamental frequency thermal cycling mainly falls on the high wind speed area, whereas the consumed lifetime due to low frequency thermal cycling is clustered in the area due to large low frequency junction temperature fluctuations. The resulting distribution characteristics can be used in the thermal management for reliability improvement.     

IGBT SPICE model

During the last few years, great progress in the development of new power semiconductor devices has been made. The new generation of power semiconductors is capable of conducting more current and blocking higher voltage. The IGBT (insulated gate bipolar transistor) is an outgrowth of power MOSFET technology. More like a MOSFET than a bipolar transistor in structure, the IGBT has some of the electrical characteristics of both. Like a MOSFET, the gate of the IGBT is isolated, and drive power is very low. The on-state conduction voltage of an IGBT is similar to that of a bipolar transistor. However, SPICE users are constantly faced with the inability to analyze circuits that contain devices that are not in the SPICE library of the semiconductor models. With the authors' own computer program, a complete macromodel of the IGBT for the SPICE simulator has been computed. In this paper, a complete IGBT SPICE macromodel is described and verified with experimental results     

Experimental study on the influence of junction temperature on the relationship between IGBT switching energy loss and device current

Accurate determination of power losses in semiconductor devices is important for optimal design and reliable operation of a power converter. The switching loss is an important component of the total device loss in an insulated-gate bipolar transistor (IGBT) in a voltage source inverter. The objective here is to study experimentally the influence of junction temperature on the turn-on switching energy loss E_on and turn-off switching energy loss E_off. More specifically E_on and E_off are both related to device current I_c; the influence of junction temperature on the relationship between E_on and I_c and that between E_off and I_c is studied. As the operating environmental conditions and load conditions of power converter vary widely, a wide range of junction temperatures between − 35 °C and + 125 °C is considered here. The experimental data enable precise determination of the switching loss in each device in a high-power converter at any practical operating condition. This leads to precise estimation of total device loss and optimal thermal design of the converter. This further helps off-line and/or on-line estimation of device junction temperatures required for study of thermal cycles and reliability.     

Pulse measurements of transient thermal response and temperature of avalanching p?n junction

A method is presented for measuring the junction temperature and the transient thermal response of oscillator-mounted avalanche diodes; the method requires an exact knowledge of the temperature dependence of the diode breakdown voltage. The junction temperature can be measured with unchanged accuracy within the measured temperature range of the breakdown voltage. The transient response as close as a few microseconds after the initiation of the junction-temperature step can be measured.     

IGBT热阻测量方法的综述

通过对近年来国内外IGBT热阻测量技术进行分析,根据各方法测量原理不同归类为四种方法:热敏参数法、数学物理法、实测结温法、红外扫描法。描述了近年来热阻测量的不断改进之处,并总结了各测量方法的优缺点。最后分析了热阻测量的发展趋势和所需解决的关键问题。     

New technique for the measurement of the static and of the transient junction temperature in IGBT devices under operating conditions

A novel technique is presented, which uses dI_ce/dt and the transconductance as a thermo-sensitive parameter for the measurement of the static and of the transient average junction temperature in IGBT devices. The paper describes the physics of the signal generation, provides the experimental setup, and discusses the accuracy and the suitability of the technique under operating conditions of the devices.     

Lifetime estimation of IGBT modules for MMC-HVDC application

Modular multilevel converters (MMCs) usually work in harsh operating environments due to their compact layouts and adverse mission profiles, which accelerate the thermomechanical fatigue process in insulated-gate bipolar transistor modules (IGBTs). Accurate lifetime estimation is desired to conduct reliability prediction and develop maintenance policies. This paper presents an analytical approach to estimating the lifetimes of IGBTs for MMC-HVDC application based on the thermal cycles, which are influenced by the transmission power profile and ambient temperature profile. The structure and operating principle of MMCs are studied to develop an analytical model for computing the IGBT power loss. A thermal equivalent network in the form of a Foster model is adopted to link the power losses and junction temperature. Next, an RC equivalent circuit analytical method for characterizing the fundamental-frequency thermal cycles, developed using electrothermal analogy theory, is proposed. The rainflow counting algorithm is applied to extract the low-frequency thermal cycles from the annual junction temperature data computed at every minute. The Bayerer model is employed to predict the IGBTs lifetime. Finally, the lifetime distribution, mission profiles and comparison of different IGBTs are analyzed via case studies.     

A new IGBT behavioral model

In this paper, we present a new behavioral model valid for insulated gate bipolar transistors (IGBTs). The d.c. part of the model is based on an empirical formula for the IGBT and needs three data points on the I–V curves to generate the entire d.c. characteristics. The dynamic part of the model is based on a Hammerstein-like current source. A template written in the MAST language is created in Saber simulator based on this new model. The theoretical predictions of the model are compared with the experimental data available for IGBTs fabricated by various manufacturers and found to be in excellent agreement. Furthermore, the new model is consistently faster than the existing physical models in simulating various circuit topologies.     

The microwave circuit model of Josephson junction at liquid nitrogen temperature

We have measured the microwave characteristics of Josephson junction at liquid nitrogen temperature by using microwave network analyser. Based upon these experimental results we present a microwave circuit model of Josephson junction at liquid nitrogen temperature and calculate the parameters of microwave circuit model of Josephson junction.

     

Fast and accurate IGBT model for PSpice

A new PSpice IGBT model is presented which combines existing BJT and MOSFET models and equations to give a more realistic drain-gate capacitance model. Electrical simulation performance gives the accuracy of complex equation based models, but involves the computational time of simple inaccurate model based approaches. Simulation and experimental results vindicate the new model     

IGBT模块电流取样电阻模型仿真

绝缘栅双极型晶体管(IGBT)模块作为一款重要的半导体功率开关器件,现已被广泛应用。然而,IGBT在工作中常会因为各种原因导致其失效,如过压、过流、过热等。为了更好的监测IGBT的工作状态,本文采用取样电阻来检测电流,通过对IGBT模块DBC底板集成的分流采样电阻进行建模与仿真,研究取样电阻的测量特性。     

功率半导体IGBT热击穿失效的可靠性研究

针对变频空调使用缘栅双极型晶体管（IGBT）击穿短路故障进行分析,确认IGBT为过压损坏失效。,空调供电电源出现大的波动影响芯片供电电源质量,电压偏低导致IGBT开通异常,不能及时欠压保护,IGBT长时间处于工作在放大状态,IGBT开通损耗大热击穿失效。本文主要从电路设计,工作环境,模拟验证等方面分析研究,确认IGBT击穿短路失效原因,从设计电路与物料选型优化提升产品工作可靠性。     

多角度热红外亮温值的模型拟合与应用

通过二向性反射率分布函数(BRDF)核驱动模型对黑河试验多角度热红外机载数据的拟合,证明了核驱动模型具有热红外波段的外延能力,确定了适用于多角度热红外数据的最佳核函数组合.在热辐射方向性核系数组合因子与地表温度(LST)构成的特征空间中构建、提取了多角度热红外干旱指数(MTDI).在黑河各试验区,MTDI和温度植被干旱...     

An electrical model with junction temperature for light-emitting diodes and the impact on conversion efficiency

We present an electrical model for quantum-well light-emitting diodes (LEDs) with a current-spreading layer. The LEDs studied have a multiquantum well (MQW) between p-GaN and the n-GaN grown on sapphire. The model consists of a diode connected with a series resistor resulting from the combined resistance of the p-n junction, contacts, and current spreader. Based upon this model, the I-V curve of the diode itself without the series resistance is extracted from the measured LED I-V curve. The model also includes an empirical diode current equation which was sought by matching the extracted I-V curve. In the seeking process, junction temperature (T/sub j/) rather than case temperature (T/sub c/) was used in the equation. The diode model allows one to calculate the reduction on conversion efficiency caused by the series resistor. Results show that the current-spreading layer causes 20% of the efficiency reduction at T/sub j/=107/spl deg/C.