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关键词： Keller-Segel模型   最优控制   Leray-Schauder不动点定理   必要最优性条件  

摘要： 本文研究一类非线性趋化方程的双线性最优控制.首先利用Leray-Schauder不动点定理证明抛物型方程组强解的存在唯一性,其次通过极小化序列讨论最优控制的存在性,最后通过控制状态算子L的Fréchet可微性建立了变分不等式并得出一阶必要条件.

关键词： ABB   电控   自动化岸边集装箱起重机   变频器   PLC   传感器  

摘要： 本文全面解析了ABB电控在岸边集装箱起重机自动化中的应用,展示了ABB电控系统的关键技术优势,探讨了变频器、PLC及传感器技术的特点与优势,分析了其在提升作业精确度、稳定性、安全性等方面的作用,并实现了远程监控和优化作业流程。本文深入剖析了在提升、小车移动、大型车辆行走机构及自动化作业控制系统中的具体应用模式,对我国港口物流的进步具有重要借鉴意义。

关键词： 自转着陆   最优控制   自转轨迹   跟踪控制  

摘要： 针对直升机自转着陆飞行控制问题,设计了多约束条件下的轨迹优化方法,基于积分滑模控制理论提出了轨迹跟踪控制方法,实现自转着陆的自主飞行控制。首先建立自转飞行过程的直升机非线性动力学模型;将自转着陆过程转化为最优控制问题,选取飞行时间和操纵总量为指标,设定飞行状态和着陆条件约束,利用高斯伪谱法快速得到安全自转轨迹;考虑飞行扰动影响,结合积分滑模控制理论设计了外环位置控制器和内环姿态控制器,准确跟踪期望轨迹的同时具有良好的鲁棒性;最后通过数值仿真验证了自转轨迹优化方法和轨迹跟踪控制方法的有效性。

关键词： 变频器故障诊断   建模仿真   小波变换   麻雀优化算法   支持向量机  

摘要： 变频器是矿井提升系统的核心设备,其主电路在高压高频环境下工作易出现故障导致变频器无法正常工作。为提升系统安全性,本文提出一种基于麻雀算法(SSA)优化支持向量机(SVM)的变频器主电路故障诊断模型。首先构建变频器电路模型,分析其输出波形,并通过小波分解提取故障特征信号,构建特征向量。随后,采用SVM作为故障诊断算法,利用特征数据进行训练和测试。针对SVM参数设定问题,本文引入SSA进行参数优化。以ABB公司的ACS800型变频器为实验对象,测试结果显示,该模型在故障诊断方面具有显著效果。

关键词： IGBT module   power loss   robustness   robustness   junction temperature   junction temperature   thermal monitoring   thermal monitoring   reliability   reliability   reliability  

摘要： Online temperature monitoring of IGBTs is a crucial means to enhance the reliability of high-power converters. In the existing thermal model methods, the junction temperature is derived through the device power loss, which is difficult to obtain accurately in real time. This paper proposes a power loss observer to estimate the real-time power loss accurately. Unlike conventional methods, the proposed method only needs measure the heatsink temperature. Moreover, the proposed technique is robust to disturbances such as wind speed fluctuations, solder aging, and temperature dependence of thermal parameters, which helps to improve the temperature estimation accuracy throughout the full life cycle of IGBT modules. This paper analyzes the proposed method's mathematical principle, algorithm, and implementation steps, while the loss observer is validated by simulation and experiment.

关键词： Insulated-gate bipolar transistor (IGBT)   Remaining useful life (RUL)   Multi-precursor prognostics   Machine learning   Classification algorithms  

摘要： The reliability of motor drives plays a crucial role in all motion control applications. Due to circuit overstresses, the IGBTs used in motor drives are prone to degradation and aging, which may result in motor drives failure. The RUL prediction of IGBT gives early warning of the unexpected IGBT failures, by predicting the useful life of IGBT while it is in operating condition. The existing methods for RUL prediction of IGBT focus on the use of a single precursor which cannot effectively determine the level of degradation of IGBT, and the methods are too laborious and have prediction errors. This work employs three precursors VCE(ON), IC and VGE, and uses a simple yet effective method to predict the RUL of IGBT by machine learning techniques, and the results are tested using online-accelerated IGBT aging data from the NASA's Ames Research Centre. The data preprocessing and feature selection are carried out using MATLAB toolboxes, namely Data Cleaner and Diagnostic Feature Designer. Then, the MATLAB Classification Learner toolbox is used to train the various machine learning classifiers, and a comparison is made for various cases involving single, double and multi-precursor parameters in predicting RUL of IGBT. Hyperparameter tuning of the machine learning classifiers is also done, and evaluation metrics such as Precision, Recall, F1 score and ROC-AUC are used to validate the performance of the different ML classifiers. Highest classification accuracy of 99.6% is obtained with ensemble, neural networks and KNN model classifiers after hyperparameters were optimized.

关键词： IGBT   Junction temperature   Temperature uniformity   Thermal management   Thermal resistance   Thermal reliability  

摘要： Renewable energy and electric vehicles are crucial subjects of the global transition towards a sustainable future. Insulated gate bipolar transistors (IGBTs) are essential components of these systems, generating substantial heat during operation. This review provides a comprehensive overview of the thermal control strategies for IGBTs, covering fundamental concepts, heat generation mechanisms, thermal failure modes and state-of-the-art cooling techniques. The review emphasises the reduction of junction temperature, thermal resistance and temperature gradient in IGBT chips and modules. Various cooling technologies are explored, including air and liquid cooling with novel configurations, PCM-based cooling, two-phase cooling (microchannels, thermosyphon and vapour chambers), nanofluid-based cooling, spray and jet impingement and hybrid configurations. This review highlights the significance of flow rate, fluid type, cooling system configuration and flow type (single or two-phase) on cooling performance. Key findings from extensive research are summarised, including the inadequacy of natural air circulation for thermal buffering, the effectiveness of passive cooling techniques for low to moderate heat generation, effectiveness of two-phase cooling for elevated heat flux and the directions for making the cooling systems hybrid (active and passive). This review sums up by discussing the outlook, challenges and future directions in IGBT thermal management, emphasising the need for further investigation into the diverse areas of thermal management leading towards the implications of the research at commercial level.

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

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： Circuit faults   Insulated gate bipolar transistors   Switches   Production   Performance evaluation   Gate drivers   Degradation   Current measurement   Bridge circuits   Topology   failure prognosis   fault analysis   IGBTs   parameter shift   post-fault diagnosis   reliability  

摘要： Modular design is largely applied to Medium Voltage Converters and provides a simple way to replace a set of damaged devices after failure events, allowing a fast return to operation. Arranging the power semiconductors into converter phase modules for instance, allow the system to be taken out of operation only for the defective phase module replacement, which can be sent to the supplier for repair. However, the indication of the failed power semiconductors inside the phase module is usually only given by the gate driver and simple in-circuit tests performed with the aid of a multimeter during the downtime. In this paper, it is demonstrated that a failure occurring in one flat-pack IGBT power semiconductor of any phase can cause escalated consequences and basic tests may not be enough to spot degraded devices in other phase modules. This is performed by the modeling, simulation, and analysis of two consecutive faults in a real case application of a three-level medium voltage converter. Furthermore, post-fault offline tests are performed in flat-pack IGBT samples that apparently survived the real case fault. The results reveal a relevant parameter shift that support questioning the benefits of the modular design. The deteriorated power devices might not fail immediately, but they will have a shorter lifetime expectancy impacting the overall reliability leading to a subsequent fault of likely larger significance [G. Salvador Ferreira et al. 2023], [G. Salvador Ferreira et al. 2024].

关键词： Insulated gate bipolar transistors   Voltage   Resistance   Ion implantation   Performance evaluation   Logic gates   Electrons   Doping profiles   Charge carrier density   Manufacturing processes   Reverse-conducting IGBT   snapback effect   high-energy ion implantation   process-compatible  

摘要： A snapback-free and process-compatible reverse-conducting insulated gate bipolar transistor (RC-IGBT) is proposed and investigated. It features the embedded N-buffer layer introduced by high-energy ion implantation in the drift region. The mechanism, process flow and its simulation validation are presented. In forward conduction, this design facilitates electronic current flow through the increased collector short resistance in unipolar mode, effectively eliminating the snapback effect without compromising other characteristics. Simulation results show the proposed snapback-free RC-IGBT achieves forward voltage drops of 1.49 and 2.09 V forward voltage drop at J(C) = 100 and 200 A/cm(2), and ON-state voltage of 1.6 V for the integrated FWD at 150 A/cm(2) with 52 mu m half- cell pitch. The fabrication process for the proposed device is simple and compatible with current manufacturing processes. These demonstrated device performances, as well as the simple structure make our proposed device highly attractive in future high performance applications.