课程文献中心 更多>>

关键词： High-speed train   Insulated Gate Bipolar Transistor (IGBT)   Liquid-cooling plate   Sensitivity analysis   Reasonable matching   ORTHOGONAL EXPERIMENTAL-DESIGN   JUNCTION TEMPERATURE   TRANSFER ENHANCEMENT   SINK   PERFORMANCE   OPTIMIZATION   TUNNEL   RIBS  

摘要： High-power insulated gate bipolar transistors (IGBTs) are important components of traction inverter. It is important to ensure the suitable temperature of the IGBT module for keeping the operation of trains efficient and safe. Due to the significant differences in train operating environment and traction performance, the cooling requirements for IGBT are also different. Therefore, identifying and matching various parameters of operating parameters of flow and heat transfer in high-power-density IGBT module liquid-cooling plate is of great significance to achieve optimal energy efficiency. Based on the Reynolds-averaged Navier-Stokes equations, shear stress transport k-omega turbulence model, and orthogonal experimental design, the flow and heat transfer characteristics of the liquid-cooling plate were simulated, and the numerical method and settings were verified experimentally. The results show that the single-parameter mapping relationship between the operating parameters and cooling performance indices (pressure drop, temperature rise, and maximum surface temperature, corresponding to Delta p, Delta T, and T-max, respectively) of the liquid-cooling plate is clear, and the flow rate and physical properties of the cooling liquid have significant effects on the cooling performance. The multi-objective optimization method based on the radial basis function surrogate model and nondominated sorting genetic algorithm II can match operating parameters under the minimum of Delta p, T-max and maximum of Delta T. Considering the appropriate values of the three indexes comprehensively based on Pareto optimal solution set, the error between the calculated value and the predicted value is less than 8 % when the inlet flow rate is 20 L/min, the temperature is 330.68 K, the pressure is 2.2 bar and the calorific value is 75.2 kW/m(2). The results can be to provide a method and database for engineers to design liquid-cooling plate for high-speed train IGBT to achieve the highest e

关键词： Data fusion   Kalman filter   IGBT   Nonstationary signal   Recurrence plots   Recurrence quantification analysis   QUANTIFICATION ANALYSIS   PLOTS  

摘要： Degradation is a nonstationary process that necessitates using a specialized measurement tool. In light of this, a degradation assessment tool has been presented in this study through the use of recurrence analysis. A fused signal has been constructed through the linear Kalman Filter Fusion Application (KFFA) to assess the growing degradation within the system. This approach aims to combine the features provided by different mediums of the system. A case study is presented using the collector-emitter current and package temperature signals collected during an IGBT 's accelerated aging experiment. Time-frequency and recurrence analyses of fused and collected signals are evaluated to interpret the degradation through the nonstationary characteristics of the signals. The study has two main purposes: to investigate the combination capability of KFFA deeply for nonstationary processes and to define recurrence analysis as a degradation assessment tool. The study explores the relationship between degradation mechanisms and chaotic tendencies. Employing recurrence analysis successfully captures the decay moment of the degradation process. The study is distinctive in its investigation of the recurrence characteristics of a fused signal, which is the mixed representation of multiple sensor data. Additionally, the study demonstrated that the linear KFFA is highly effective in providing integrated and more reliable information even for nonstationary signals. With these contributions, the paper proposes a novel degradation assessment tool driven by recurrence analysis and supported by KFFA.

关键词： Insulated gate bipolar transistor   Junction temperature estimation   Thermal management   Inverter   POWER   RELIABILITY   CONVERTERS  

摘要： Insulated gate bipolar transistors (IGBTs) are widely used in grid-connected renewable energy generation. Junction temperature fluctuation is an important factor affecting the operating lifetime of IGBT modules. Many active thermal management methods for suppressing junction temperature fluctuation exist, but research on the implementation of thermal management in converters is limited. Junction temperature extraction is the basis of implementing thermal management. In this study, a thermal network model method and a temperature-sensitive electrical parameter (TSEP) method for junction temperature estimation are analyzed first. Aiming to limit the maximum junction temperature of IGBTs, a thermal management method is proposed by changing switching frequency. Then, for a three-phase two-level inverter, the effectiveness of the proposed thermal management method is analyzed by offline simulation based on the thermal network model method. Lastly, the IGBT junction temperature in the inverter is estimated online by using the TSEP method and the feasibility of the thermal management implementation method is verified on an experimental platform.

关键词： Thermal performance   Energy conservation   Field synergy   Entropy generation   CONVECTIVE HEAT-TRANSFER   TRANSFER ENHANCEMENT   LAMINAR-FLOW   ION BATTERY   PERFORMANCE   MANAGEMENT   SINKS   MICROCHANNELS   PRINCIPLE   EFFICACY  

摘要： A thermal-and-energy-conservation optimization was numerically investigated in this work for a liquid-cooled plate (LCP). Firstly, a three-dimensional model was established, and its numerical analysis was verified with experimental data. Then, the common correlations of heat transfer synergy beta and pressure synergy theta involving the amplification factor, the width of cooling columns, the number of cooling columns, the height and the width of flow passage were derived from the traditional Colburn factor j and Fanning friction factor f correlations, which were later solved by the least-square method and tested with regression and joint hypotheses test. With those correlations, a multi -objective optimization was performed, and its outcomes were assessed by a comprehensive evaluation index Comprehensive synergy gamma for thermal performance and auxiliary entropy generation for energy conservation. At last, Optimized Scheme 2 (OS2) was numerically compared with the original one to confirm improvements. It is found that, over the whole speed range, the maximum error between both results is 6.61 %. The test shows that the fitting correlation may predict 94.79 % of beta with a -0.039 % mean error and 98.96 % of theta with a 0.099 % mean error. Among outcomes, OS2 contributes a better gamma, 51.3465 degrees, for thermal performance and a smaller entropy generation, 0.09175 W/K, for energy conservation. Furthermore, the comparison also supports that finding with the decreased beta of 0.39 %, the decreased theta of 3.33 %, the increased gamma of 0.34 %, and the increased entropy generation of 3.99 % in OS2. The research results can provide a basis for the design and development of a high -power loader.

关键词： Nuclear power plant rod position indicating   and rod control system   IGBT   Feature extraction   SDAE   LSTM   Life prediction  

摘要： To reduce the losses caused by aging failure of insulation gate bipolar transistor (IGBT), which is the core components of nuclear power plant rod position indicating and rod control (RPC) system. It is necessary to conduct studies on its life prediction. The selection of IGBT failure characteristic parameters in existing research relies heavily on failure principles and expert experience. Moreover, the analysis and learning of time-domain degradation data have not been fully conducted, resulting in low prediction efficiency as the monotonicity, time correlation, and poor anti-interference ability of extracted degradation features. This paper utilizes the advantages of the stacked denoising autoencoder(SDAE) network in adaptive feature extraction and denoising capabilities to perform adaptive feature extraction on IGBT time-domain degradation data; establishes a longshort-term memory (LSTM) prediction model, and optimizes the learning rate, number of nodes in the hidden layer, and number of hidden layers using the Gray Wolf Optimization (GWO) algorithm; conducts verification experiments on the IGBT accelerated aging dataset provided by NASA PCoE Research Center, and selects performance evaluation indicators to compare and analyze the prediction results of the SDAE-LSTM model, PSOLSTM model, and BP model. The results show that the SDAE-LSTM model can achieve more accurate and stable IGBT life prediction.

关键词： Conversion unit   DC-AC converter   IGBT   Temperature  

摘要： This research article discusses the impact of climatic changes in South America, with a case study in a tropical zone, particularly the rise in temperature by 1.15 degrees C from 1998 to 2022, reaching a maximum of 45.85 degrees C in 2023. Focusing on the Electronic Conversion Unit, especially IGBT efficiency during El Nino-Southern Oscillation phenomenon in 2023. The case study employs finite element analysis using Navier Stockes-Boussinesq equations, it evaluates the heat dissipation, airflow modeling, and temperature effects, the research proposes enhancements like redesigned air flow grids, centralized air filters, and wind fans. Implementing these improvements reduces the temperature by 5.6 degrees C, enhances airflow speed, and mitigates the climatic impact on electronic devices over the next two decades.

关键词： IGBT并联   均流特性   驱动差压   异步间隙  

摘要： 动态均流问题是限制多IGBT模块并联应用的关键。开通电流时刻，电流上升率和电流峰值等过程变量形式影响多支路IGBT开关过程的一致性。基于并联支路IGBT驱动控制回路的固有参数差异，该文提出并联IGBT差压异步驱动技术，通过调节驱动脉冲异步间隙和改变驱动电压幅值与持续时间，协调控制不同支路的IGBT门极脉冲，驱动各支路IGBT开关过程电流一致。研究开关过程中驱动信号异步间隙、驱动差压与电压调整时间对动态电流斜率不均衡度的影响，分析控制参数耦合关系，优化参数设定方法。基于实际IGBT模块参数，建立器件工作特性数学模型，进行并联IGBT开关仿真分析，开展应用该方法的驱动实际工况测试，结果证明所选优化设计参数可以明显改善并联IGBT模块开关动态均流特性，验证了差压异步驱动控制优化参数设计方法可行性。

关键词： Non-punch-through insulated gate bipolar transistor (NPT-IGBT)   Hot carrier induction   Collision ionization rate   Charge pumping   TCAD simulation  

摘要： In this paper we present measurement results of hot-carrier-induced degradation of NPT-IGBT under the condition of voltage applied on its collector. The effect of hot carriers on NPT-IGBT is investigated in three ways: stress test measurement according to the gate voltage under the voltage of 400 V applied, TCAD (Tsuprem4 and MEDICI) simulation and electric charge pumping test measurement. The experimental results confirm that the proposed structure of NPT-IGBT has sustainable characteristics and enables the hot-carrier-induced degradation to be effectively optimized in order to guarantee the stability of the device.

关键词： 自适应动态规划   折扣衰减项   最优控制   灵活性   神经网络  

摘要： 针对离散仿射非线性系统,利用自适应动态规划提出了一种新的带有折扣衰减项的最优控制方法.首先,引入了衰减项构造性能指标函数,克服了传统研究中折扣因子忽略后续时刻对系统性能的影响,提高了系统的控制性能.其次,不同于传统的折扣因子算法,本文对性能指标函数序列进行分析,证明了折扣衰减项能够提高系统的灵活性,避免传统迭代过程中的局部收敛问题,并利用神经网络实现了该算法.接着,构造了单调递增或递减的迭代性能指标函数序列并证明了系统的渐进稳定性.最后,通过仿真实例验证了算法的有效性.

关键词： IGBT   数据驱动   老化参数   迁移学习  

摘要： 针对绝缘栅双极型晶体管(IGBT)的健康状态及剩余使用寿命评估问题，本文基于迁移学习AdaRNN模型预测IGBT的老化参数。首先分析IGBT的失效机理，选择集电极-发射极导通电压作为评价IGBT健康状态的老化参数；然后搭建IGBT老化实验台，在线采集该老化参数；最后基于采集的老化参数，利用AdaRNN模型实现IGBT老化参数预测。结果表明，使用同一IGBT老化参数作为训练集与测试集时，传统时序模型和AdaRNN模型预测结果的精度与速度相似；使用两组不同IGBT的老化参数作为训练集与测试集时，AdaRNN模型可解决由于器件差异导致的老化参数差异问题，预测的准确度明显高于传统时序模型，模型的泛化能力和鲁棒性强。