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关键词： current balance   interleaved   IGBT   two-phase boost converter  

摘要： A zero-current-transition (ZCT) strategy is proposed herein. This strategy is applied to a two-phase boost converter with isolated gate bipolar transistors (IGBTs) used as main switches. However, IGBTs have a current tail during the switch-off interval. Consequently, the proposed constant-frequency ZCT strategy along with common-ground auxiliary switches is employed to decrease the switching loss generated by the current tail. Furthermore, the light-load efficiency can be upgraded by regulating the switch-off instants and switch-on times of the two auxiliary switches. Moreover, two phases are interleaved with one phase having a phase difference of 180 degrees from the other phase, and controlled by a current-sharing controller so that the input current can be distributed between the two phases as evenly as possible. Moreover, only one current sensing circuit is required to obtain information on currents in the two main switches. Above all, the number of phases can be extended with easy control of the ZCT and current balance.

关键词： Multi -chip IGBT module   Thermal analysis   Solder layer aging   Thermal diffusion angle   Thermal coupling   Junction temperature estimation  

摘要： With the continuous increase in the scale of new energy grid-connected, high-power converter IGBT modules are widely used in wind, solar, and other new energy power generation systems. The safe and reliable operation of IGBT modules with parallel chips is becoming more and more important. In the multi-chip module, uneven solder aging will increase the thermal resistance of some chips, which will lead to an inaccurate estimation of the junction temperature of the multi-chip IGBT power module. To this end, this paper proposes to use the recon-structed thermal impedance matrix to modify the multi-chip thermal network model and estimate the junction temperature. By analyzing the nonlinear accelerated deterioration law between the aging degree of the solder layer and the self-thermal impedance and coupled thermal impedance of the IGBT module, the influence mechanism of different solder layer aging degrees inside the module on the thermal conduction radius and thermal diffusion angle is clarified. The thermal impedance matrix is reconstructed with the modified thermal diffusion angle, thus realizing the optimization of the thermal network model of the multi-chip IGBT module. The experimental results show that the junction temperature calculation results of the improved multi-chip IGBT module thermal network model are more in line with the finite element simulation than the traditional unim-proved method, thus verifying the validity and accuracy of the model, and laying a solid foundation for the large-scale integrated multi-chip thermal analysis. Theoretical basis.

关键词： IGBT modeling   parameter extraction  

摘要： Extracting gate-drain overlap oxide capacitance (C-oxd) is a necessary step for almost all kinds of insulated-gate bipolar transistor (IGBT) compact models. There are two datasheet-driven methods that are universally accepted, one is based on reverse capacitance voltage characteristics (C-V method), and the other uses gate charge characteristics (Q-V method). This letter is to reveal the underlying mechanism of these two methods. It is found that the C-V method has an inescapable shortcoming which will mistake the turn-OFF delay time forecasted by IGBT models. In this letter, the internal capacitance system of IGBT is modeled and demonstrated completely. Based on this model, the accuracy and feasibility of the C-V and Q-V methods are analyzed. Moreover, the effect of C-oxd on IGBT compact models is studied and further verified by experiments and circuit simulations.

关键词： IGBT   Dielectric barrier discharge   Drive circuit   Inverter power supply   Protection circuit  

摘要： Purpose This paper aims to improve the general circuit of driving and protection based on insulated gate bipolar transistor (IGBT) in dielectric barrier discharge power supply by designing a novel half-bridge inverter circuit with discrete components. Design/methodology/approach With one SG3524 chip, the structure based on discrete components is used to design the IGBT drive circuit. The driving waveform is isolated and sent out by photo-coupler 6N137. The protection circuit is realized by Hall sensor directly detecting the main circuit current, supplemented by a few components, including diodes, resistors, capacitors and triodes. It improves the reliability of the protection circuit. Findings In the driving circuit, the phase difference of signals from two channels are 180 degrees. Moreover, when the duty cycle is set at 40%, it can ensure sufficient pulse width modulation response time. In the protection circuit, when over-current occurs, an intermittent output signal is automatically sent out. Furthermore, the over-current response time can be controlled independently. The peak voltage can be adjusted continuously from 0 to 30 kV with its frequency from 8 to 25 kHz and the power output up to 150 W. Originality/value The novel circuit of driving and protection makes not only its structure simpler and easier to be realized but also key parameters, such as frequency, the duty cycle and the driving voltage, continuously adjustable. Moreover, the power supply is suitable for other discharges such as corona discharge and jet discharge.

关键词： Insulated gate bipolar transistors   Sensors   Temperature measurement   Temperature sensors   Temperature distribution   Fiber gratings   Junctions   Fiber Bragg grating (FBG) head size   FBG sensor   insulated gate bipolar transistor (IGBT)   junction temperature   on-chip thermal sensing   thermal distribution  

摘要： This article studies the influence of fiber Bragg grating (FBG) head length on insulated gate bipolar transistor (IGBT) direct on-chip thermal sensing performance of FBG sensors. To this end, the surface of a commercial IGBT chip is thermally simulated and experimentally characterized. Uniform FBG sensors with three head sizes are then tested in two promising thermal sensing locations. The study has found that the large thermal gradients in this application create an additional constraint when using longer head lengths. A distortion in the reflected spectrum of the 5-mm FBG sensor is used to illustrate the underlying physical effect, which causes this limitation for IGBT junction temperature measurement. This additionally affects the length of head sizes providing accurate temperature readings of the IGBT surface hotspots, and significantly, this limit is location-dependent in a given IGBT geometry.

标准号: GB/T 32877-2022

摘要： 本文件概述了GB/T 755-2019范围内的电动机在变频器供电时确定损耗和效率的试验方法及插值程序，所述电动机也是GB/T 12668.902-2021所定义的调速电气传动系统（PDS）的一部分。用本文件的比较变频器法所确定的电动机效率仅用来比较不同的电动机设计。

关键词： 德力西集团   不忘初心   成长期   变频器   成长史   萌芽期   发言权   新征程  

摘要： 2004年,隶属于德力西集团旗下德力西变频器成立,当时国内变频器企业也如雨后春笋般的兴起,可以说德力西变频器的成长史见证了中国变频器企业从萌芽期到成长期进入发展壮大的关键时期。谈及变频器的国产替代之路,段龙很有发言权。

关键词： 带式输送机   变频控制系统   变频器  

摘要： 针对煤矿输送设备的快速输送、高承载能力和长输送距离的要求,进行PLC输送机变频控制系统优化设计。通过现场实践验证了优化设计的可行性,该变频控制系统提高了带式输送机的煤炭输送效率同时减少了电力能源损耗,可有效保证输送机设备的工作状态和煤炭资源的安全开采,对煤矿安全生产具有重要的意义。

关键词： 性别结构   稳定性   一致持续   敏感性分析   最优控制  

摘要： 通过考虑同性接触与异性接触来研究HIV/AIDS的传播,建立带有性别结构的HIV/AIDS模型.根据下一代矩阵法求出基本再生数.证明当R_(0)<1时,无病平衡点是全局渐近稳定的,当R_(0)> 1时,地方病平衡点是存在的,并且疾病是一致持续的,并通过数值模拟来验证结论.提出一个最优控制问题并利用庞特里亚金极大值原理进行了求解.拟合结果表明我国未来几年患病人数仍会不断攀升.

关键词： “最优化理论与最优控制”   课程思政   研究生教育  

摘要： “最优化理论与最优控制”是控制科学与工程专业研究生的一门专业基础课。挖掘课程相关的思政元素并将其与专业知识有机融合,有利于培养学生的专业认同感以及锐意进取、严肃认真的学习态度,激发学生爱国热情,增强学生责任感和使命感,让课程教学充分发挥立德树人作用。文章分析了本课程概况及研究生专业课程思政教学中存在的问题,提出合理设计思政元素、设置具有思政特色的教学环节、改进教学方式、优化思政效果评价体系等策略,以期在教学中完成知识的传授并潜移默化地帮助学生树立正确的世界观、人生观、价值观。