同步电动机励磁控制装置的改造

针对同步电动机KGLF-10型励磁控制系统采用模拟插件控制方式时,存在工作不稳定、线路繁杂、故障率高、调试困难等问题,确定了采用基于PLC励磁控制装置的改造方案.     

On-line broken-bar fault diagnosis system of induction motor

Induction motor faults including mechanical and electrical faults are reviewed. The fault diagnosis methods are summarized. To analyze the influence of stator current, torque, speed and rotor current on faulted bars, a time-stepping transient finite element (FE) model of induction motor with bars faulted is created in this paper. With wavelet package analysis method and FFT method, the simulation result of finite element is analyzed. Based on the simulation analysis, the on-line fault diagnosis system of induction motor with bars faulted is developed. With the speed of broken bars motor changed from 1 478 r/min to 1 445 r/min, the FFT power spectra and the wavelet package decoupling factors are given. The comparison result shows that the on-line diagnosis system can detect broken-bar fault efficiently.     

韶山7E电力机车交流变频电动机的技术特点

交流变频电动机是电力机车的一种新装置，本文主要介绍了韶山7E电力机车交流变频电动机的技术特点。     

Zero-voltage switching converter absorbing parasitic parameters for super high frequency induction heating

This paper presents a novel mega-Hz-level super high frequency zero-voltage soft-switching converter for induction heating power supplies. The prominent advantage of this topology is that it can absorb both inductive and capacitive parasitic components in the converter. The switch devices operate in a zero-voltage soft-switching mode. Consequently, the high voltage and high current spikes caused by parasitic inductors or capacitors oscillation do not occur in this circuit, and the high power loss caused by high frequency switching can be greatly reduced. A large value inductor is adopted between the input capacitor and the switches, thus, this novel converter shares the benefits of both voltage-type and current-type circuits simultaneously, and there are no needs of dead time between two switches. The working principles in different modes are introduced. Results of simulation and experiments operated at around 1 MHz frequency verify the validity of parasitic components absorption and show that this convener is competent for super high frequency applications.     

开关图的谱

首先根据开关图的定义用原图的邻接矩阵表示其开关图的邻接矩阵,然后用原图的特征多项式表示其开关图的特征多项式．对于正则图,用正则图的谱表示其开关图的谱．     

无刷直流电动机闭环调速系统虚拟实验平台设计

利用Matlab图形用户界面开发工具GUI设计无刷直流电动机单、双闭环调速系统的虚拟仿真实验平台。采用Simulink仿真技术搭建后台无刷直流电动机单、双闭环调速系统仿真模型。针对无刷直流电动机参考转速变化、负载转矩变化等情形,在虚拟仿真实验平台进行无刷直流电动机单、双闭环调速系统虚拟仿真实验,实验结果验证了所建立仿真模型的正确性和虚拟实验平台的实用性。通过仿真实验教学,加深学生对所学内容的理解,激发学生的学习兴趣,加强学生创新思维和创新能力的培养。     

三相异步电动机节能的技术分析

本文主要阐述了电机节能原理、电机节能存在的主要问题、提高电机运行效率、减少有功损耗等问题.     

宝钢三期2000千瓦4极交交变频隐极式同步电动机的设计特点

本文简要介绍2000千瓦4极交交变频隐极式同步电动机的设计特点,包括如何确定电动机的额定功率,选择电磁负荷参数,对于电动机连接到变频电源的三种接法作了分析比较。     

一种单管ZVS-ZCS-Buck-PWM变换器

本文介绍了一种单管ZVS-ZCS-Buck-PWM变换器,简述了其工作原理。讨论了相关器件的参数设计问题,仿真证明了理论分析的正确,该变换器在高频开关电源中有很好的应用前景。     

10kV配电变压器保护配置方式的合理选择

10 kV配电变压器的保护配置主要有断路器、负荷开关或负荷开关加熔断器等。负荷开关投资省,但不能开断短路电流,很少采用;断路器技术性能好,但设备投资较高,使用复杂,广泛应用不现实;负荷开关加熔断器组合的保护配置方式,既可避免采用操作复杂、价格昂贵的断路器,弥补负荷开关不能开断短路电流的缺点,又可满足实际运行的需要,该配置可作为配电变压器的保护方式,值得大力推广,为此,对10kV环网供电单元和终端用户10kV配电变压器采用断路器、负荷开关加熔断器组合的保护配置方式进行技术-经济比较,供配电网的设计和运行管理部门参考。