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关键词： IGBT   gate oxide layer degradation   feature fusion   performance prediction   MultiScaleFormer network  

摘要： Insulated gate bipolar transistors (IGBTs) are widely used in power electronic devices, and their health prediction problems have attracted much attention in the field of power electronic equipment health management. The performance degradation of IGBT gate oxide is one of the most important failure modes. In order to analyze this failure mechanism and the ease of implementation of a monitoring circuit, the gate leakage current of IGBTs was selected as the fault precursor parameter for the degradation of their gate oxide performance, and feature selection and fusion were carried out by using time domain characteristic analysis, grayscale correlation, Mahalanobis distance, Kalman filter, and other methods. Thus, a health indicator was obtained to characterize the degradation of IGBT performance, which was used to indicate the degree of aging of the IGBT gate oxide layer. In this paper, we propose an improved degradation prediction model called MultiScaleFormer, inspired by advanced design ideas of the iTransformer network architecture, combined with the health parameters of IGBTs to construct a degradation prediction model for the IGBT gate oxide layer. MultiScaleFormer showed the highest fitting accuracy compared with the Long Short-Term Memory (LSTM), Convolutional Neural Network (CNN), Support Vector Regression (SVR), Gaussian Process Regression (GPR), CNN-LSTM, and Transformer models in our experiment. The mean absolute error (MAE) of the MultiScaleFormer prediction was as low as 0.0087. Extraction of the health indicator and the construction and verification of the degradation prediction model were carried out on the dataset released by the NASA-Ames Laboratory. These results demonstrate the feasibility of the gate leakage current as a fault precursor parameter for IGBT gate oxide failure, and the feasibility and accuracy of the MultiScaleFormer prediction model for IGBT performance degradation.

关键词： IGBT   Gate charge   Collector current model   Double-pulse experiment  

摘要： In this study, a dynamic and static collector current (IC) model of the IGBT based on the gate charge is proposed. The gate charge could be easily obtained by measuring the voltage across the gate mirror circuit capacitance, and the transconductance obtained from the IC-VGE curve is mainly used. This model does not need the device structure parameters such as doping concentration, length, and thickness, thus is low cost and highly convenient. First, the gate charge is derived by integrating the currents of the variable capacitors CGE and CGC during the turn-on and turn-off transients, and an analytical relationship between the dynamic IC and QG is researched. Second, a static collector current IC is established, and the gate charge is obtained through current integration during the period of the Miller capacitance plateau. The influence of the temperature on the static transconductance is studied, and the accuracy of the static current model is improved. Finally, the performance of the model is optimized with various voltages, temperatures, and currents. The experimental results reveal that the proposed model achieves a collector current error of less than 5.6 % under various operating conditions, which verifies the accuracy of the proposed model.

关键词： Temperature measurement  

摘要： Thin-film thermocouple are widely used to measure the local temperature on the surface, which can adapt to the narrow working space of the device and be applied to the temperature measurement field of IGBT chip. Ni 90%Cr 10% and Ni 97%Si 3% thin-film thermocouple were prepared on polyimide thin-film substrates by magnetron sputtering technique, and static calibration and repeatability calibration were carried out, and the results showed that the Seebeck coefficients of the prepared thin-film thermocouple temperature sensors were 40.23 μV/°C and with the increase of the temperature, the repeatability error tended to be 0.3%. In this paper, the IGBT output current of different sizes, add heat sink, switching frequency and control signal duty cycle, etc. © 2024, The Authors. All rights reserved.

关键词： Junction temperature model   Solder layer voids   Heat flow distribution   Temperature difference  

摘要： The presence of voids in a solder layer affects the thermal reliability of an insulated-gate bipolar transistor (IGBT). In this work, the effects of the size and fraction of solder layer voids and the power losses of chips on heat flow distribution, junction temperature and thermal resistance were investigated. It was found that it was difficult for the heat to flow through the voids due to the high thermal resistance of air. Therefore, the heat above the voids could only flow horizontally, and then avoid the voids and move downward in the solder layer and the following layers, leading to a temperature difference in the surface chip layer. An improved junction temperature model based on the heat flow distribution (HD) considering the solder layer voids was established, the horizontal thermal resistance and horizontal heat capacity are introduced to characterize the effect of the solder layer voids, and the parameter extraction method was proposed. The temperature difference on the surface of the module increased with the increase of the void fraction, and when the void fraction increased from 0 % to 40 %, the surface temperature difference increased from 9.591 degrees C to 109.86 degrees C. The results showed that the proposed model not only had a higher accuracy in the estimation of the junction temperature compared with the traditional Cauer model and the improved Cauer model, but also monitored the horizontal temperature differences in the chip layer precisely.

关键词： Insulated gate bipolar transistors (IGBT)  

摘要： A fast-switching low-loss field-stop insulated gate bipolar transistor with a dual control gate (DIGBT) of a semi-insulating polycrytalline silicon (SIPOS) material is proposed in this paper. Because the SIPOS has uniform high resistance, it has an approximate linear electric potential distribution. When DIGBT conducts, the higher electric potential on SIPOS causes the P-type drift region (P-drift) to generate an inversion layer of electrons, adjusting the number of carriers and making the generation of non-equilibrium carriers no longer dependent on the doping concentration in P-drift (N-d) but on the electric potential distribution on SIPOS. Therefore, it can solve the contradiction among the breakdown voltage, forward voltage drop [V-CE(sat)], turn-off time (t(off)), and turn-off loss (E-off) caused by the N-d. Through Technology Computer Aided Design (TCAD) simulation, the V-CE(sat) of DIGBT is 30.6% lower than that of SJFS IGBT. Meanwhile, DIGBT reduces the t(off) by 62.8% while reducing the E-off by 83.0% compared to SJFS IGBT. In addition, the static latch-up I-V and the forward biased safe operating area of the DIGBT have been significantly improved. This paper adjusts the number of carriers through the characteristics of SIPOS material, enabling the above-mentioned physical phenomena to be applied in insulated gate bipolar transistor power devices and achieving device performance breakthroughs.

关键词： PV array   Multi-level inverter   IGBT   Open-circuit faults   diagnosis   DT-TC   Fault-tolerant   reconfigurable  

摘要： A lot of previous studies have shown a great interest in connecting photovoltaic (PV) arrays to electric power grids. A Maximum Power Point Tracker (MPPT) controlled 100 kW PV array to boost its power that feeds the grid with the help of a three-level inverter. This paper investigated the effects of open-circuit faults of three-level inverter IGBT switches on the performance of the PV array system. This paper proposes a new diagnostic method called the Double Threshold-Trigonometric Coordinates (DT-TC) that relies on the double threshold technique and the trigonometric coordinates, respectively, for early detection and the precise location of open-circuit faults. To the best knowledge of the authors, two simultaneous open-circuit faults were not considered in the previous studies. The obtained simulation results prove the great success of the proposed diagnosis method even under noticeable changes in irradiation, temperature, and the number of PV array connected in series and in parallel. In this study, the reconfigurable fault-tolerant inverter was included to ensure the perfect continuity of the PV array system and its recovery in an extremely very short time up to 7 ms.

关键词： 苯基改性有机硅凝胶   绝缘封装   热稳定性   击穿强度   高温耐电  

摘要： 随着绝缘栅双极型晶体管(insulated gate bipolar transistor,IGBT)向高电压、大功率化方向发展,其产生的热量和运行温度快速上升,致使其绝缘封装系统失效问题愈发突出。为满足IGBT日益严苛的工作环境,亟需研发一种高性能的有机硅灌封材料。该文通过化学合成制备苯基改性有机硅凝胶(phenyl modified silicone gel,PMSG),研究其耐热和介电性能。结果表明:PMSG失重5%的热失重温度为383℃,室温击穿场强可达32.62 kV/mm,比纯有机硅凝胶(pure silicone gel,PSG)提高17.42%,且150℃击穿场强相较于室温击穿场强仅下降25.38%,展现出更优良的高温耐电特性。同时,其相比于PSG具有更低的介电损耗。因此,PMSG作为IGBT封装材料时,整体性能更加优良。该研究将为IGBT封装用新型高性能绝缘材料的研制提供有效思路和理论基础。

关键词： 故障电弧   故障检测及选线   变分模态分解   核主成分分析   支持向量机  

摘要： 串联故障电弧的高温是引发电气火灾的主要原因之一,针对工业变频器负载回路中串联故障电弧尚无有效保护手段的问题,提出了一种新的串联故障电弧检测及选线方法。首先,针对工业领域常用的三相变频器负载回路开展了不同线路中发生串联故障电弧的实验;其次,利用基于能量收敛原则改进的变分模态分解将变频器前端A相电流信号自适应分解为多个模态分量,依次将单个模态分量乘以能量系数并重构,得到多个电流信号的特征增强信号,并建立特征矩阵;再次,对特征矩阵进行分块,利用核主成分分析对每块矩阵进行降维,并对降维信号组成的矩阵进行二次降维构建故障特征向量;最后,利用鹈鹕算法优化的支持向量机对串联故障电弧进行检测及选线。结果表明:该方法仅通过分析变频器前端A相电流可以实现变频器整个回路中6条线路的串联故障电弧检测及选线,检测及选线准确率均达到98%以上。

关键词： IGBT   驱动电路   串并联  

摘要： 基于绝缘栅双极型晶体管(IGBT),分析其基本参数,通过电压驱动方式,以平面变压器为基础,设计快速驱动电路,实验结果表明:IGBT集电极电流上升率(di/dt)约为10.13A/ns,提高了约8.1倍。通过分析IGBT失效模式和串并联均压均流的影响,利用瞬态抑制二极管(TVS)的特性,设计串联有源钳位电路;通过电路布局优化等方式设计并联均流电路,并进行2串2并的IGBT阵列实验,通过实验验证均流均压效果,并根据典型寿命预测模型计算Nf为124005。

关键词： 热连轧机   板形控制   平直度   凸度   最优控制  

摘要： 为进一步提升热连轧机板形控制效果,满足理想板形的生产需求,在综合分析影响热连轧钢材板形控制因素的基础上,提出从算法和策略层面对板形控制等方面进行优化的总体思路,设计了板形凸度、平直度的二次反馈控制框图和基于最优控制算法的体系控制系统,并通过仿真验证了板形控制优化的效果。