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关键词： PLC   变频器   触摸屏   联机运行   调速系统  

摘要： 电动机的调速控制是工业实际中常用的功能,也是工程技术人员需较好掌握的技能。本论文基于西门子s7-1200系列PLC(1214)和V20变频器,配套SIMATIC HMI屏,通过一个小型案例,完成电机的多种调速控制,利于对简易自动控制系统的理解,帮助读者实现PLC、变频器、触摸屏的联机运行,同时掌握电动机固定速度、模拟量调速、随机定速的一种实现方法。

关键词： 双有源桥   DC-DC变换器   电流应力   动态性能  

摘要： 针对双有源桥DC-DC变换器电流应力及动态性能问题,提出一种基于双重移相控制、结合电流应力优化方案,引入负载电流前馈的方法。首先,通过Karush-Kuhn-Tucker(KKT)算法得到双重移相控制下双有源全桥最小电流应力的移相角关系;其次,对变换器引入负载电流前馈控制,使得电流应力减小的同时,提高变换器的动态响应能力。仿真结果表明,与传统单移相控制相比,在输入电压突降、负载突增等情况下,优化控制策略提高了变换器动态性能,降低了电流应力。

关键词： 双向DC-DC变换器   串联谐振变换器   零电压开通   模式切换  

摘要： 串联谐振变换器由于其高效率、低电磁干扰等优良性能,在新能源系统中得到了广泛的应用。针对传统双向谐振变换器增益范围较窄、双向工作模式切换困难的问题,本文提出了一种双向串联谐振变换器固定载频积-移相控制策略。该控制策略采用变频移相调制方式,维持品质因数与频率相关变量的乘积为优化选取的固定值,实现了变换器所有开关管的零电压开通,并通过改变副边全桥相对于原边全桥的移相角实现宽范围的双向电压增益调节。通过对载频积参数的优化设计,抑制了谐振腔环流能量,提高了变换器的效率。此外,控制策略可以实现双向工作模式的自动切换,切换过程快速、平滑,适用于能量双向流动的储能系统应用场合。最后搭建了原边电压340 V、副边电压52 V、额定功率2 kW的实验样机,验证了控制策略的可行性和优越性。

关键词： 超声波焊接   PIN针超声焊接   焊接工艺参数  

摘要： 在功率模块中,PIN针的连接强度对IGBT的性能和使用寿命产生了直接影响.使用超声波焊接工艺代替传统的钎焊工艺,具有较高的精度和较好的焊接强度.基于此,对焊接工艺参数进行实验,研究PIN针超声焊接的焊接强度随焊接压力的变化规律.通过对超声波焊接工艺的进一步研究,有望为工业界提供更加优良的焊接方案.

关键词： S120   变频器   故障   方法  

摘要： S120系列的变频器在冶金、造纸、石油、化工等领域得到广泛应用,在企业中发挥着重要的作用。但在应用中还会出现一些故障,需要对产生的故障进行深入的分析,提出行之有效的解决方法,降低故障率。同时更有效地控制及调节电机速度,使其在更优的状态下运行,更好地为生产服务。文中介绍了S120系列变频器的结构及工作原理,对现场变频器在使用过程中出现的常见故障问题进行详细的分析,提出了相应的解决方法,确保设备快速恢复运行,同时也为其他用户在S120系列变频器出现类似故障时提供借鉴。

关键词： 模拟主轴   数控系统   变频器   倍率调速  

摘要： 为满足经济型数控机床对主轴部分控制功能的需求,采用FANUC 0i-MF Plus数控系统和三菱FR-D700变频器开发数控机床模拟主轴控制功能。给出设计方案和电气原理图,以及详细的开发调试过程,包括CNC主轴参数设置、变频器参数设置、PMC程序编制,同时分析4种实现倍率调速的方法。调试结果表明:所开发的模拟主轴能很好地满足启停换向和倍率调速的控制要求,具有良好的实用价值和经济效益。

关键词： 变频技术   皮带输送机   主从控制   变频器  

摘要： 皮带运输是煤矿井下最主要的运煤方式,现在大多数煤矿皮带输送机的驱动电机通过液力耦合装置实现起动,但使用这种方式会出现起动时不平稳、皮带承受张力过大和多个电动机扭矩难以均衡等问题,产生很大的功率消耗问题。为解决这一问题,对皮带运输机进行变频技术改造,使用变频调速系统,皮带运输机启动将缓慢平稳,延长皮带的使用寿命。采用主-从控制变频调速系统,可以使多个电机转矩平衡,减少电能损耗。本文着重研究煤矿皮带输送机变频技术改造的优点,以及面临的技术困难。

关键词： Inverter paralleling   Radiated electromagnetic interference   Circuit radiation model   Field-circuit coupling  

摘要： The electromagnetic radiation interference mechanism from multiple noise sources on the parallel topology of SiC MOSFET and Si IGBT Inverter is blurred, which will seriously affect the high reliability application of the structure. In order to solve this problem, a topological radiation EMI prediction method is proposed, the method includes the establishment of radiation equivalent models and radiation guidelines, the proposed inverter parallel topology radiation. The modeling method of electromagnetic interference can effectively analyze the influence of radiation interference of SiC and Si devices coupled with each other, and the established PCB radiation near and far field simulation can effectively realize the accurate prediction of radiation interference of inverter parallel topology, and finally the experimental platform of the parallel SiC MOSFET and Si IGBT inverter is built and tested, the test results demonstrate the accuracy of the proposed method.& COPY;2023 Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://***/licenses/by-nc-nd/4.0/).

关键词： Insulated gate bipolar transistors   Circuit faults   Interference   Integrated circuit modeling   Equivalent circuits   Inductance   Electromagnetics   Electromagnetic interference   high-voltage dc circuit breaker   overcurrent protection   stray parameter   wide-band model  

摘要： As a highly integrated high-voltage power electronic equipment in the power grid, the dc circuit breaker (dcCB) has misjudged overcurrent protection caused by the insulated gate bipolar translator (IGBT) pseudodesaturation effect (PDE) in dc short-circuit fault. To analyze the reasons for the effect, this article established a wide-band equivalent circuit model of a hybrid high-voltage dcCB at the initial stage of dc fault. And revealed the mechanism of PDE: the stray inductance of series-connected solid-state switches, the junction capacitance of metal oxide varistors, and the parasitic capacitance to the ground of dcCB form multiple resonant circuits. The external disturbance is converted into the interference of dcCB port through these stray parameters, and the interference would exceed the IGBT desaturation detection threshold. Furthermore, an equivalent experimental circuit that reproduces the electromagnetic interference of dcCB at the dc fault transient process was proposed, and the correctness of the mechanism analysis was verified by the scaled prototype of dcCB, the main resonance frequency error is less than 15%. Finally, the frequency domain and time domain characteristics of electromagnetic interference on the IGBT desaturation detection monitoring ports in 200 kV dcCB at the initial stage of dc fault were analyzed. Based on these characteristics, a scheme of adding a delay time to the overcurrent protection criterion to avoid electromagnetic interference was proposed, which is adopted by an industrial project.

关键词： Insulated gate bipolar transistors (IGBT)  

摘要： Real-time temperature monitoring of power semiconductors is a powerful tool for the predictive maintenance and lifetime prediction of power converters, and is typically performed by measuring temperature sensitive electrical parameters (TSEP). In this work, we demonstrate a machine learning-based method to estimate the on-state voltage of a real converter prototype featuring variable load of electric vehicle (EV) and photovoltaic (PV) systems under different ambient temperatures induced in a climate chamber. The method provides for the first-time insights on the uncertainties and feature importance for the predictions, and is aimed to be industrial compatible by applying only methods that are well established in industry. The approach is further flexible to any converter system, independently of its specifications. We have used the Support Vector Machine, K-Nearest Neighbors, and Decision Tree algorithms to predict the on-state voltage as functions of the readily measured parameters of a converter. We show that for the PV case, the K-Nearest Neighbor method yields the lowest mean absolute error of about 0.75 % for prediction, while for EV, the K-Nearest Neighbor algorithm gives the lowest mean absolute error of 5 %. © 2023 The Author(s)