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关键词： 国际能源署   电力公司   数据显示   能源供应   太阳能光伏   太阳能逆变器  

摘要： 国际能源署的数据显示,到2030年,太阳能光伏(PV)装置的装机容量有望达到3,300TWh,与2019年的水平相比,年增率为15%[1],这意味着能源供应的比例在不断上升。光伏装置的安装是将微型、迷你和电力公司规模的混合,但无论哪种情况都采用类似的PV技术,电池串联可获得较高的可用电压,并联可获得更高的功率。

关键词： 门座起重机   变频器   起升机构   散粮抓斗  

摘要： 门座起重机应用在散粮装卸码头主要通过25 t抓斗对船舱货物进行抓料,主要分为两组钢丝绳进行起升及开闭动作,其驱动方式采用变频调速。本文通过对散粮抓斗与门机变频器的控制关系进行分析,阐述了一起因开闭变频器导致的散粮抓斗无故障报警的异常动作故障的处理,对门机变频器在散粮抓斗时的应用提出了改良方案。

关键词： 高压变频器   事故分析   防范措施  

摘要： 近年来,随着资源节约型和环境友好型社会建设的持续推进,国家越发重视节能降耗工作,尤其是电力行业等高能耗产业,为了积极响应国家的节能降耗政策,其开始广泛应用高压变频器,且获得了较好的节能效果。但是,高压变频器在使用时也存在一些问题,基于此,本文就高压变频器事故展开研究,首先介绍了变频器,其次对其事故进行了分析,并提出了相应的防范措施,希望能够降低高压变频器的事故发生率,确保其运行安全可靠。

关键词： 扩张状态观测器   噪声抑制   异步电机   自抗扰控制器  

摘要： 异步电机矢量控制过程中通过测速装置获取电机转速信息,而检测元件由于受到干扰、量化误差以及电机运行状况等因素影响,导致转速信息中混有噪声需要经过滤波处理,但传统的转速滤波方法不能兼顾实时性和精度要求。线性扩张状态观测器具有系统输出信号滤波的功能,在传统线性扩张状态观测器通道增加滤波环节提高噪声抑制能力,对观测器升阶处理以提高观测能力,进而解决系统响应速度与控制器噪声抑制方面的矛盾。在频域中通过伯德图对线性自抗扰控制器的稳定、跟踪、抗扰性能进行了分析,理论分析表明改进后的自抗扰控制器能够削弱控制器输入与系统反馈处噪声带来的影响,仿真结果也验证了控制器噪声抑制的有效性。

关键词： 着陆制导   可回收运载火箭   最优控制   强化学习   垂直回收  

摘要： 可回收运载火箭的着陆制导需要严格保证着陆位置、速度精度,并尽量减小燃料消耗。基于最优控制的着陆制导方法需要依赖火箭精确模型,不具有对模型偏差的泛化能力。针对此问题,本文基于强化学习方法,通过不基于模型的交互采样,训练了神经网络形式的火箭着陆制导策略。首先,建立火箭着陆制导问题的马尔可夫决策过程模型,根据终端约束和燃料消耗指标设计了分阶段奖励函数;然后,在此基础上设计了多层感知机制导策略网络,并使用不基于模型的邻近策略优化算法,通过与火箭着陆制导马尔可夫决策过程的交互采样,实现对制导策略网络的迭代优化;最后,在可回收运载火箭着陆段仿真场景下对制导策略进行验证。仿真结果表明,本文提出的强化学习着陆制导策略能够保证火箭的着陆精度、燃料消耗与最优解相近,且能够泛化至火箭模型参数存在偏差的工况。

关键词： PLC   变频器   自动化生产线  

摘要： 本文介绍了PLC联合变频器在自动化生产线中应用控制的方法。着重介绍了自动化生产线的系统组成、控制系统中PLC与变频器的硬件连接方法、PLC软件程序编写、变频器参数设置等内容,经验证表明,该方案简单可行,能实现预期的控制要求。

关键词： PIN power diode   Parameters extraction   PSPICE   TCAD   CARRIER LIFETIME   RAMP RECOVERY   SPICE MODEL   EXTRACTION   IGBT  

摘要： This paper aims to present a detailed systematic approach to identify the main design parameters of PIN power diodes. Firstly, the diode physical parameters are initialized using simple analytical equations. The second phase is the optimization of the diode parameters considering PSPICE circuit simulation where an electro-thermal physically based circuit model is utilized depending on a series of dynamic and static measurements. The final optimization step is carried out by using TCAD simulations. First, the diode extracted parameters are used to virtually fabricate the diode by using a process simulator. Then, using the output of the process simulator, a device simulator is used to get the desired output that is validated against experimental data. Three case studies for different power diodes are presented showing a good agreement between circuit/device simulation results and measurements. The presented methodology provides high accuracy like TCAD-based parameter extraction procedure with less time. In addition, it gives higher accuracy than the widely used circuit-based parameter extraction technique. (C) 2021 THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Ain Shams University.d by Elsevier B.V.

关键词： Junction temperature measurement   IGBT   Miller plateau duration  

摘要： A new method is proposed for the measurement of the junction temperature of insulated gate bipolar transistors (IGBTs) during operation. The application of this method overcomes the problems arising from the complexity of measurement circuits or the difficulty of tests. The proposed measurement method uses the turn-on Miller plateau duration (t(mon)), i.e., the duration from the first rising edge to the second rising edge of the gate-emitter voltage, of an IGBT. The obtained results show that t(mon) is strongly linear with respect to temperature. For comparison, the temperature-sensitive electrical parameters (TSEPs) turn-off Miller plateau duration (i.e., the duration between the two falling edges of the Vge-off curve) were also measured. The obtained results show that t(mon) exhibits a high sensitivity that permits accurate determination of the junction temperatures of IGBTs.

关键词： Failure characteristic parameters   Junction temperature prediction   Cuckoo Search   Extreme learning machine   REMAINING USEFUL LIFE   RELIABILITY   MODULE   OPTIMIZATION   PROGNOSTICS   ALGORITHM   EFFICIENT   MODEL   TIME  

摘要： The insulated-gate bipolar transistor (IGBT) is one of the most widely used power transistors in switching and industrial control systems. Its actual junction temperature plays a critical factor in determining the dynamic performance, reliability and life-time of the device. Although some noninvasive measurement methods such as optical and physical contact methods may be used to estimate the junction temperature, the measurement accuracy is very sensitive to the measured position. Therefore, the prediction using cuckoo search-based extreme learning machine for junction temperature is developed to reach a high-accuracy solution without measuredlocation sensitivity. Firstly, the accelerated aging and single pulse tests in IGBT are implemented to collect the IGBT failure related parameters, e.g. collector-emitter saturation voltage (VCE(sat)), junction temperature, collector current (Ic) and the aging cycles number. With the curved surface fitting for the collected data, the relationship between the junction temperature and the other parameters can be formed. Based on the extreme learning machine optimized by the improved Cuckoo Search method, called ICS-ELM, VCE(sat), Ic and the aging cycles number are taken as input, and the output is the predicted junction temperature. The performance results reveal that the determination coefficient (R2) by ICS-ELM model achieves the optimal value, i.e. 0.9975, which is superior to the curved surface fitting method, Cuckoo search optimizing extreme learning machine, support vector machine and extreme learning machine.

关键词： Current source gate driver   Software programmed   Double pulse tester   Output impedance   IGBT  

摘要： Stress test system development is increasingly aimed at meticulous reliability and robustness evaluation for power semiconductors under application conditions as well as qualification purposes. Newly developed silicon (Si) power devices need further investigation in terms of potential new failure mechanisms. A double pulse tester is utilized as a test vehicle for studying hard switching related failure modes. However, setting up such a repetitive reliability test for multiple channels requires substantial manual labour. This paper proposes an open loop current source gate driver (CSGD) with adjustable gate voltage which can be software programmed, enabling an operator to set variable turn on/off speeds without hand-operated switching speed adjustment by gate resistors. The CSGD performance is assessed with various hard switching speeds in experiment and simulation for a discrete TO-247 MOSFET and IGBT respectively. Finally, additional considerations are proposed for faster switching so as to overcome the inherent nonlinearities and the CSGD output impedance effects.