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关键词： IGBT   AlN   cu joint   Brazing   Residual stress   Microstructure  

摘要： The aluminum nitride (AlN) ceramic is a underlying substrate material for high-voltage/power insulated gate bipolar transistors (IGBT), due to its excellent thermal conductivity and low coefficient of thermal expansion (CTE). The high-quality joining between AlN and Cu, which have a huge CTE mismatch and large residual stress remained in the joint, is the prerequisite for the application of AlN in IGBT. In this work, a AgCuTi-Al brazing filler was designed to connect the AlN and pure Cu. The element Al with a low melting point of 660 degrees C would decrease the brazing temperature, alleviating the residual stress level in the joints. In addition, Al could react with Cu and Ti in the liquid filler to in situ produce AlCu2Ti intermetallic compounds (IMCs), contributing to the mitigation of CTE mismatch and amelioration of joint bond strength. A heterogeneous structure in relieving the residual stresses would be driven based on the modulation of filler composition and joining condition, while the microstructural optimization and enhancement in mechanical properties could be achieved. Based on this, effects of Al content, brazing temperature, and soaking duration on the microstructure and mechanical properties of the AlN/Cu joints were investigated. The formation process and strengthening mechanism of the joints were also discussed. The work performed may provide useful strategies for the manufacture of high-performance packaged substrates in IGBT.

关键词： Insulated gate bipolar transistors   Logic gates   Wires   Monitoring   Fatigue   Voltage   Reliability   Chip branch failure   condition monitoring   gate charge   multichip insulated gate bipolar transistor (IGBT) modules  

摘要： The reliability of the multichip insulated gate bipolar transistor (IGBT) modules has been a concern. Condition monitoring is an effective approach to enhance reliability and improve the quality of customer service. This article proposes a method for monitoring the chip branch failure due to bond wires fatigue in the multichip IGBT modules. The idea is based on the cumulative effect of the gate charge deviation when the chip branch fails. By integrating the turn-on gate current of multiple switching cycles, the health state of multichip IGBT modules is characterized by the capacitor voltage as a health-sensitive parameter that can be extracted in the proposed monitoring circuit integrated into the gate driver. The capacitor voltage decreases significantly when the chip branch occurs due to bond wires fatigue. It is stable during sampling and has a strong immunity to junction temperature, collector current, and collector-emitter voltage. Besides, the method is nonintrusive and has the potential for real-time and online monitoring. These characteristics make the method reliable, easy to implement, and convenient for health status identification. The confirmatory experiment is carried out to verify the feasibility of the method.

关键词： IGBT   gate oxide layer degradation   feature fusion   performance prediction   CNN-LSTM network  

摘要： The problem of health status prediction of insulated-gate bipolar transistors (IGBTs) has gained significant attention in the field of health management of power electronic equipment. The performance degradation of the IGBT gate oxide layer is one of the most important failure modes. In view of failure mechanism analysis and the easy implementation of monitoring circuits, this paper selects the gate leakage current of an IGBT as the precursor parameter of gate oxide degradation, and uses time domain characteristic analysis, gray correlation degree, Mahalanobis distance, Kalman filter, and other methods to carry out feature selection and fusion. Finally, it obtains a health indicator, characterizing the degradation of IGBT gate oxide. The degradation prediction model of the IGBT gate oxide layer is constructed by the Convolutional Neural Network and Long Short-Term Memory (CNN-LSTM) Network, which show the highest fitting accuracy compared with Long Short-Term Memory (LSTM), Convolutional Neural Network (CNN), Support Vector Regression (SVR), Gaussian Process Regression (GPR), and CNN-LSTM models in our experiment. The extraction of the health indicator and the construction and verification of the degradation prediction model are carried out on the dataset released by the NASA-Ames Laboratory, and the average absolute error of performance degradation prediction is as low as 0.0216. These results show the feasibility of the gate leakage current as a precursor parameter of IGBT gate oxide layer failure, as well as the accuracy and reliability of the CNN-LSTM prediction model.

关键词： 电动客车   分布式驱动   转矩矢量   控制策略  

摘要： 基于分布式驱动电动客车的特点,采用基于分层控制架构的转矩矢量控制策略。策略上层设计基于LQR的直接横摆力矩控制算法,下层设计基于经济性和稳定性的转矩分配控制策略。并进行实车验证。

关键词： 压接型IGBT   全接触   疲劳寿命   岭回归   多变量拟合  

摘要： 柔性直流输电技术的飞速发展,对换流阀用压接型IGBT器件的可靠性要求进一步提高。目前针对压接IGBT可靠性寿命模型的研究存在不足,一方面,大多数模型对接触问题考虑不全面,物理模型为焊接形式或不能滑动的联合体,不符合实际物理机理,因此可靠性模型不能全面真实反映实际情况。另一方面,解析寿命模型的拟合方法,无法单一控制变量完全解耦,单变量拟合曲线并不能准确反应变量与可靠性寿命的关系。建立了考虑全部接触问题的功率循环计算模型,针对压接型器件的封装特点引入压力作为新变量,提出一种采用改进多元线性回归拟合方法的多变量寿命模型,该分析方法可应用于压接型IGBT在功率循环下的可靠性评估。通过有限元计算结果验证,多变量寿命模型相比单变量拟合更加准确。

关键词： 水处理   HMI   变频器   自动巡检  

摘要： 以某管理中心净水系统进行简要的应用分析,介绍该系统的构成及功能。研究系统中水泵的控制原理,并结合工作经验和自动化控制理念,阐述HMI、变频器等在净水系统中的应用,提出水泵自动巡检功能的可行改进方案,为日后净水处理系统工程建设提供参考意见。

关键词： controllable hole-extracting path   energy loss   frequency characteristics   Si C insulated gate bipolar transistor(IGBT)  

摘要： A novel 4H-Si C trench insulated gate bipolar transistor(IGBT)with a controllable hole-extracting(CHE)path is proposed and investigated in this *** CHE path is controlled by metal semiconductor gate(MES gate)and metal oxide semiconductor gate(MOS gate)in the p-shield *** grounded p-shield region can significantly suppress the high electric field around gate oxide in Si C devices,but it weakens the conductivity modulation in the Si C trench IGBT by rapidly sweeping out *** effect can be eliminated by introducing the CHE *** CHE path is pinched off by the high gate bias voltage at on-state to maintain high conductivity modulation and obtain a comparatively low on-state voltage(VON).During the turn-off transient,the CHE path is formed,which contributes to a decreased turn-off loss(EOFF).Based on numerical simulation,the EOFFof the proposed IGBT is reduced by 89%compared with the conventional IGBT at the same VONand the VONof the proposed IGBT is reduced by 50%compared to the grounded p-shield IGBT at the same *** addition,the average power reduction for the proposed device can be 51.0%to 81.7%and 58.2%to 72.1%with its counterparts at a wide frequency range of 500 Hz to 10 k Hz,revealing a great improvement of frequency characteristics.

关键词： 模糊PID补偿算法   变频器   异步电动机   同步控制   适应度函数  

摘要： 为解决变频器运行功率不稳定的问题,实现对异步电动机的同步性控制,针对基于模糊PID补偿算法的变频器调速异步电动机同步自动控制方法展开研究。根据模糊PID补偿算法应用原则,求解变频适应度函数,实现对变频器元件运行速率的初步调节。对应瞬时无功功率指标的取值范围,求解电流谐波、电压谐波计算式,实现对异步电动机的同步自动控制。对比实验结果表明,模糊PID补偿算法作用下,变频器运行功率能够长时间稳定在400~450 W的额定功率区间内,可以较好地解决变频器运行功率不稳定的问题,符合同步控制异步电动机的实际应用需求。