课程文献中心 更多>>

关键词： 焦炉机车   变频器   高负载运行   故障分析  

摘要： 焦炉机车广泛应用于钢铁生产中的焦炭运输和装卸过程,是焦炉生产线的重要组成部分。分析焦炉机车变频器在高负载运行中的常见故障类型,深入探讨故障原因,在此基础上提出故障解决措施,旨在提升变频器在高负载条件下的可靠性和稳定性。

关键词： 感应电机   矢量控制   SVPWM   自适应模糊PID   电梯系统  

摘要： 通过建立感应电机数学模型,设计改进的空间矢量脉宽调制(SVPWM)策略,并引入自适应模糊PID控制器,实现了电机转速和转矩的精确控制。仿真结果表明,该方法可有效降低电机转速波动,提高转矩响应速度,减少能耗。进一步通过实际电梯系统测试验证了该方法的可行性和优越性,为电梯系统感应电机的设计优化提供了新的思路。

关键词： 改进极限学习机   SVG散热风扇   变频控制   模糊控制   蚁狮优化   变频器  

摘要： 为降低变频控制超调量,设计基于改进极限学习机的SVG散热风扇变频控制方法,提升变频控制效果。通过温度传感器实时采集SVG的运行温度,在极限学习机内引进模糊控制理论,改进极限学习机,并通过蚁狮优化算法,优化改进极限学习机的参数,降低变频控制误差;在参数优化后的改进极限学习机内,输入SVG散热风扇实际运行温度与设定运行温度间的温差,以及温差变化率,输出SVG散热风扇变频器的工作频率,实时控制SVG散热风扇转速与排风量,实现SVG散热风扇变频控制。实验证明,该方法可有效变频控制SVG散热风扇转速与排风量,使SVG运行温度稳定在安全范围内,且该方法的变频控制超调量较小,在不同条件下的应用鲁棒性较强。

关键词： 模块化多电平换流器   误差优化   1D-CNN   开路故障  

摘要： 由于模块化多电平变换器(modular multilevel converters,MMC)实际模型中采样误差、电路参数不准确等因素,现有故障诊断策略存在鲁棒性差、阈值难选取等难题。为解决上述问题,提出了一种基于电容电压预测采样优化的MMC多管开路故障诊断策略。该策略将逐段误差优化后的电容电压、输出电流和环流作为故障诊断显性特征,利用结构简单、适应力强的一维卷积神经网络(one-dimensional convolutional neural network,1D-CNN)作为新的故障定位方案,实现MMC高精度开路故障诊断。所提方法无需增加额外传感器,在故障子模块电容电压变化的初始阶段即可实现子模块多管故障的快速准确定位。相较于现有基于电容电压的诊断策略,该方法极大地降低了系统参数误差,保证了故障诊断网络的鲁棒性。最后,仿真和实验验证了所提故障诊断策略的有效性。

关键词： 变频器   电机   谐波   应对措施  

摘要： 变频器与电机距离较远将会产生较大谐波,对系统运行产生影响。本文主要探讨谐波的实际影响与应对措施,根据谐波产生的基本原理,明确不同类型的谐波影响问题,并结合某谐波治理案例进行分析,发现安装电抗器、滤波器可有效抑制谐波,缩短变频器与电机的距离可避免谐波危害系统,由此提出多相脉冲整流改造系统、科学选择电抗器与滤波器、加强谐波控制三项措施,保障系统稳定运行。

关键词： 共母线   能量回馈   电梯节能   变频器  

摘要： 共母线电梯能量回馈技术是电梯再生能量回收利用的一种有效方法。阐述了曳引电梯的工作原理以及现有2类电梯节能装置的工作原理及其优缺点,介绍了一种共母线交换技术在电梯能量回馈装置中的应用及其主要特点和优势,并跟踪一个实际加装电梯能量回馈装置的实际案例,采用实际工况法对其节能情况进行测量,节电率达到了35.3%,具有良好的社会效益。

关键词： 低压变频器   双机冗余架构   效能评估  

摘要： 低压变频器作为工业电机驱动与控制的关键设备,其运行可靠性直接关乎整个生产流程的安危。本文聚焦低压变频器双机冗余架构在工业环境中的应用,此架构针对故障停机易酿安全事故或有特殊故障停机要求的重点设备,深入探究其工作原理、应用场景、可靠性、成本效益等维度,阐述双机冗余在工业应用中的核心价值。通过构建多维度的效能评估体系,对其可靠性、可用性及成本效益展开全面评估。研究旨在为工业企业在电力驱动系统选型与优化方面提供科学依据,助力提升工业生产的稳定性、效率与经济效益,推动工业自动化技术的持续发展。

关键词： 电梯故障   变频器   电网质量   使用工况  

摘要： 本文针对一起电梯变频器运行质量导致设备停运的原因的调查,进行了详细的现场勘验、检验检测和技术分析。通过综合分析,确定了电梯故障的主要原因是变频器输入转换模块损坏,进一步探讨了导致模块损坏的电网质量、使用工况和运行环境等因素。基于分析结果,提出了针对性的改进措施,旨在提高电梯的安全性和可靠性,同时避免纠纷。

关键词： Germanium   Logic gates   Power electronics   Bonding   Wire   Threshold voltage   Insulated gate bipolar transistors   Current measurement   Voltage measurement   Safety   Die failure sensitive parameters (DFSPs)   gate-auxiliary emitter turn-off voltage overshoot and undershoot   insulated-gate bipolar transistor (IGBT) die failure   multidie IGBT power module (MDPM)  

摘要： High-power converters often employ insulated-gate bipolar transistor (IGBT) modules with multiple dies connected in parallel. Evaluating the die open-circuit failure degree caused by all bonding wire liftoffs can provide failure warnings to enhance reliability. This article proposes the undershoot ( $V_{\text {ge}<^>{\prime }\_{\text {us}}}$ ) and overshoot ( $V_{\text {ge}<^>{\prime }\_{\text {os}}}$ ) based on the gate-auxiliary emitter voltage during the turn-off process as two novel die failure sensitive parameters (DFSPs) for evaluating die failure degrees. First, the analysis reveals that die open-circuit failure leads to a decrease in $V_{\text {ge}<^>{\prime }\_{\text {us}}}$ and $V_{\text {ge}<^>{\prime }\_{\text {os}}}$ , which are unaffected by operating conditions. Then, a double-pulse test platform is constructed to investigate the effects of die failure and various factors on $V_{\text {ge}<^>{\prime }\_{\text {us}}}$ and $V_{\text {ge}<^>{\prime }\_{\text {os}}}$ . The experimental results demonstrate that as the number of failed dies increases, the proposed DFSPs decrease. Moreover, the failure sensitivity is enhanced, and the method remains insensitive to variations in operating conditions. Finally, a pulse counting-based evaluation method and a circuit are proposed. This method relies solely on pulse pattern recognition without requiring precise DFSP sampling, thus offering a novel evaluation mode. The proposed circuit supports plug-and-play functionality without needing high-performance analog-to-digital converters (ADCs) or timers. This method improves robustness and simplicity while ensuring safety, providing a new perspective for failure warning of the multidie modules.

关键词： Insulated gate bipolar transistors   Bonding   Wires   Temperature measurement   Junctions   Degradation   Power electronics   Switches   Monitoring   Temperature sensors   Bonding wires   discrete insulated gate bipolar transistor (IGBT)   health status   stress wave  

摘要： Effective condition monitoring (CM) technology ensures the safe operation of insulated gate bipolar transistors (IGBTs). Most CM methods for IGBTs focus on extracting electrical, thermal, and magnetic parameters. Recent studies indicate that at the switching moment, IGBTs can emit the switching stress wave (SSW) that is detectable by the acoustic emission (AE) sensors. However, using these SSWs to monitor the health status of IGBTs, even for discrete devices with relatively simple package structures, remains challenging. This article investigates how SSWs from discrete IGBTs during power cycling change as bonding wires degrade and whether these waves are promising for monitoring the condition of internal bonding wires. In this work, a power cycle test platform and an SSW test platform for discrete IGBTs are built, and SSWs from discrete IGBTs during power cycling are analyzed. Results show that SSWs vary with the degradation of the device's bonding wires, with changes in the time domain indicator of signal energy, reflecting SSW strength, and the frequency domain indicator of the center of gravity (COG) frequency, reflecting frequency shifts. These findings suggest the possibility for developing AE-based detection technology (AEDT) in CM of the IGBT.