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关键词： Voltage   Time-frequency analysis   Insulation   Needles   Electrodes   Insulated gate bipolar transistors   Dielectrics and electrical insulation   Electrical tree   encapsulation   power electronic module   repetitive square voltage   silicone gel  

摘要： The insulating properties of silicone gel, which is widely used as the encapsulation of power electronic modules, directly determine their electrical insulation reliability, so the effects of applied voltage parameters in practical application scenarios should be investigated. In this article, the effects of the frequency, rise time, and duty cycle of the positive repetitive square voltage on the initiation and growth characteristics of electrical trees in silicone gel are investigated by means of a pin-plate electrode structure to simulate spike-like defects in power electronic modules. The frequency mainly affected the growth characteristics of electrical trees after the initiation of electrical trees. The rise time has an effect on the tree inception voltage (TIV) and the duty cycle not only affects the growth characteristics of electrical trees but also the TIV. The related mechanisms are discussed and explained in detail. The findings are expected to provide guidance for the design optimization and reliability improvement of the encapsulation in high-voltage power electronic modules.

关键词： Dynamic 2-D excess carrier distribution   dynamic control lumped-charge (DCLC)-based physical model   injection enhancement (IE) effect   insulated gate bipolar transistors (IGBTs)   micropattern trench (MPT)  

摘要： Due to the injection enhancement (IE) effect, the novel micropattern-trench (MPT) insulated gate bipolar transistor (IGBT) technique could accomplish a superior balance between the ON-state voltage drop and the switching loss. Nevertheless, modeling research regarding the MPT IGBT has yet been seldom conducted. When conventional models reliant on quasi-static assumptions are employed directly, the estimation of turn-off losses may be subject to substantial error. Thus, a novel physical paradigm for the MPT IGBT based on dynamic control lumped charge (DCLC) is introduced in this article. We newly propose a charge concentration expression for a MOS end region geometry-dependent charge concentration for an MPT structure that accounts for the dynamic 2-D excess carrier distribution. Meanwhile, a DCLC power diode model is established as a more accurate representation of the IGBT's turn-on characteristic. On the assumption that device parameters are known, the carrier turn-off dynamic of the proposed IGBT model is validated through comparison with TCAD simulation. The precision of the suggested model is additionally validated through experiments that encompass both static and transient attributes.

关键词： Insulated gate bipolar transistors   Degradation   Thermal degradation   Temperature measurement   Temperature sensors   Thermal resistance   Monitoring   Case temperature matrix   condition monitoring   degradation type and level   insulated gate bipolar transistor (IGBT) module  

摘要： This article presents an intelligent approach for monitoring various thermal degradations in insulated gate bipolar transistor (IGBT) modules. Thermal degradation at the baseplate solder and thermal interface material (TIM) both induce changes in the case temperature distribution, offering insights into the corresponding degradation type and level. To capture this information, a strategically placed thermocouple array forms a temperature matrix on the case surface. The normalization of the case temperature matrix effectively mitigates the influence of working conditions, such as load current or heatsink temperature. Furthermore, a model augmented with a convolutional neural network is utilized to classify the degradation type and level based on temperature matrixes. To generate datasets under diverse operational conditions, a finite-element model of a conventional IGBT module is developed. The model includes various degradation locations (baseplate solder fatigue, TIM degradation, baseplate solder, and TIM degradation) and levels (health, early degradation, severe degradation, failure). Gaussian noise is introduced to the simulation data to enhance both training and prediction accuracy. Additionally, experimental data from a two-level inverter is incorporated into the training dataset to further refine accuracy. The results affirm that this approach excels in accurately distinguishing the degradation type and evaluating the degradation level.

关键词： Temperature measurement   Temperature sensors   Junctions   Monitoring   Degradation   Logic gates   Threshold voltage   Condition monitoring   junction temperature   multichip IGBT power module   solder layer degradation  

摘要： Asymmetric chip placement and initial die-attach defects within a multichip IGBT power module (MIPM) can cause uneven junction temperature distribution and further accelerate the solder layer degradation. This is one of the main factors which affect the performance and reliability. This study uses the auxiliary emitter voltage v(eE) to indirectly measure the turn-on delay time and the maximum rate of change of the collector current. The physical significance of the virtual junction temperature extracted from the two measurands is clarified. The correspondence between the v(eE) and the degradation level of the solder layer is established using the difference between the two estimated temperatures. A novel condition monitoring method is then proposed in this article to identify the degradation level of individual solder layers using v(eE), which separates the effects of solder layer fatigue and bonding wires lift-off. The current dependence of the proposed method is negligible. Simulation and experimental results indicate that the proposed method can sensitively detect the highest degradation level of the chip in a MIPM in real-time.

关键词： Collector-emitter voltage rise slope (dV(CE)/dt)   dynamic conduction current (DCC)   near-zero current turn-off (near-ZCT)   space-charge region (SCR)   trench gate/field-stop insulated-gate bipolar transistor (Trench-FS IGBT)  

摘要： When high-power trench gate/field-stop insulated-gate bipolar transistor (Trench-FS IGBT) modules operate at near-zero current turn-off (near-ZCT), the conventional collector-emitter voltage rise slope (dV(CE)/dt) model does not consider the extension behavior of the space-charge region (SCR) into the FS layer. In addition, it does not account for the effect of dynamic conduction current (DCC), resulting in poor model generality. To address these issues, this article first derives an expression for the voltage at the turning point where V-CE exhibits a two-stage slope, occurring as the N-base region expands into the FS layer. Furthermore, the boundary conditions for V-CE exhibiting a two-stage slope are determined. Second, based on the proposed expression and boundary conditions, accounting for the effect of DCC on the excess carrier concentration in the N-base region, a segmented analytical model for dV(CE)/dt is proposed. Finally, IGBT modules with various technologies and voltage ratings were experimentally tested. The results from simulations and hardware experiments validate the effectiveness and accuracy of the proposed method.

关键词： IGBT life prediction   successive variational mode decomposition   pelican optimization algorithm   bidirectional long short-term memory  

摘要： The precise estimation of the operational lifespan of insulated gate bipolar transistors (IGBT) holds paramount significance for ensuring the efficient and uncompromised safety of industrial equipment. However, numerous methodologies and models currently employed for this purpose often fall short of delivering highly accurate predictions. The analytical approach that combines the Pattern Optimization Algorithm (POA) with Successive Variational Mode Decomposition (SVMD) and Bidirectional Long Short-term Memory (BiLSTM) network is introduced. Firstly, SVMD is employed as an unsupervised feature learning method to partition the data into intrinsic modal functions (IMFs), which are used to eliminate noise and preserve the essential signal. Secondly, the BiLSTM network is integrated for supervised learning purposes, enabling the prediction of the decomposed sequence. Additionally, the hyperparameters of BiLSTM and the penalty coefficients of SVMD are optimized utilizing the POA technique. Subsequently, the various modal functions are predicted utilizing the trained prediction model, and the individual mode predictions are subsequently aggregated to yield the model's definitive final life prediction. Through case studies involving IGBT aging datasets, the optimal prediction model was formulated and its lifespan prediction capability was validated. The superiority of the proposed method is demonstrated by comparing it with benchmark models and other state-of-the-art methods.

关键词： Diamonds   Silicon   Insulated gate bipolar transistors   Liquids   Substrates   Surface treatment   Films   Diamond   hot-filament chemical vapor deposition (HFCVD)   insulated gate bipolar transistor (IGBT)   liquid metal   polycrystalline diamond (PCD)  

摘要： Diamond-on-Si insulated gate bipolar transistors (IGBTs) on a floating zone (FZ) silicon wafer is fabricated and investigated. The polycrystalline diamond (PCD) of the Diamond-on-Si IGBT is used for a heat spreader of high-power devices, which helps to raise the breakdown voltage and short time at the on-state so as to cool down temperature in the N-drift region in IGBT operating and reduce the turn-off power. Moreover, the Diamond-on-Si IGBT could improve more current extremely, and nano diamond particles (NDs) grain size near the interface Si/Diamond that led to a higher in-plane thermal dissipation compared with the conventional IGBT. By fine control of the seed size and areal density, thermal conductivity near multihole collector contacts region can therefore be improved. Measurement results of diamond of 140 mu m IGBT show that under turn-off loss (E-off ) of 1.24 mJ/cm(2 ), breakdown voltage (V-BR) of 1.32 kV and collector-emitter current (I-ce) is as high as 150 A/cm(2), which is superior to most of conventional IGBTs. In addition, the reasons for the Diamond-on-Si IGBTs results are also discussed in this article. Finally, the advantages of Diamond-on-Si IGBTs in terms of thermal performances are verified by measurement, and this article also provides a guideline for the process of Diamond IGBTs by the liquid Ga catalysis.

关键词： MMC-SST   PEEK   Surface partial discharge   DC voltage  

摘要： Modular multilevel converters (MMCs) have been utilized in solid-state transformers (SSTs). With the increasing demand in high-voltage power module in MMC-SST, press-pack IGBTs are very promising. The poly-ether-ether-ketone (PEEK) frame is utilized in the submodules of press-pack IGBT to withstand the high voltage. The electric field simulation in this paper reveals that electric field concentrates on the surface of the PEEK frame. Thus, the surface partial discharge characteristics under direct current (DC) voltage is investigated by the developed test bench. The results show that surface partial discharge model of PEEK sample has polarity effect. Under positive and negative polarity voltage, the average discharge quantity, maximum discharge quantity and discharge repetition rate of the PEEK sample all increase with the voltage amplitude. Moreover, the front time of the surface partial discharge waveform reaches 20 ns, and its frequency spectrum is concentrated in range of 10-20 MHz.

关键词： AC-DC power converters   Power electronics   Pulse-width modulation converters   Submarine battery  

摘要： This innovative charger-discharger utilizing the technology of IGBT, designed for lead-acid submarine batteries, is discussed in the present manuscript. Within the system, a bidirectional DC-DC converter links the Battery-Ultra Capacitor system, ensuring Depth of Charge and State of Charge are controlled very precisely to avoid sulfation. Over 12 months of field tests, IGBT chargers succeeded in obtaining 93 % charge efficiency;at its turn, the one with linear charging, provided by traditional rectifiers, for instance, was already 85 %, meaning it literally snatched huge energy savings and was cost-wise beneficial. The system showed a better thermal stability at just 2.3 degrees C standard deviation fluctuation. As per the regression, if the efficiency is improved by 1 %, the life of the battery is extended to nearly 0.53 months. The result was further confirmed by ANOVA, and the fall of batteries was predicted with 92 % accuracy with the help of a Random Forest model. As such, on balance of performance, cost, and reliability, the most appropriate technology for the submarine application is that of the IGBT rather than the SiC MOSFETs or GaN transistors. It conserves power and gas generation for improved operational efficiency and higher battery life, and improves overall sustainability.

关键词： Insulated gate bipolar transistors   Monitoring   Short-circuit currents   Logic gates   Wires   Bonding   Aging   Bonding wire   condition monitoring   health state   IGBT module   short-circuit current   temperature criterion  

摘要： The bonding wires and busbars in IGBT modules may have open points and breaks during long-term use, causing changes in short-circuit current. The health status of the IGBT module can be analyzed by detecting and judging the short-circuit current. The self-excited short circuit monitoring technology controls the gate voltage to cause small current short circuits in the IGBT. By detecting the magnitude of the self-excited short circuit current, the damage to the IGBT module bonding wire is determined. The accuracy of the monitoring results of this method is affected by changes in device junction temperature. Based on the application scenario of urban rail traction inverters, this article proposes an improved temperature criterion for the self-excited short-circuit monitoring method. The multidimensional relationship between IGBT module short circuit current, health level, and temperature changes is analyzed. The temperature ranges for self-excited short circuit detection based on the actual operating conditions of urban rail inverter is studied, and the driving module status judgment is set to only determine the health status of effective data points within the temperature range. This method can suppress the influence of IGBT working temperature on short-circuit condition detection and improve the accuracy of the criterion. At last, a current detection experiment was conducted to simulate the fracture of bonding wires, verifying the effectiveness of the proposed method.