三电平高压变频器在供水厂取水泵上的应用

以武汉钢铁(集团)公司12号水站所进行的要频改造为例,介绍了中点钳位的IGBT三电平大功率高压变频器的原理,采用"一拖二"方式运行给出了主电路图。对蓄水池水位信号的远程传送提出了解决方案。工程改造投运后水位稳定、节能效果明显,验证的方案的可行性。     

模数混合分布式逆变器并联控制方法

提出了逆变器并联运行系统一种新的分布式无主从控制策略，同步控制和均流控制解耦。前者以数字方式实现，后者基于数字和模拟混合电路实现；各并联逆变器模块之间同时实现完全电气隔离和瞬时值均流，并允许任一模块热插拔。注重分析了输出电压有效值调节在并联系统中的特性以及与均流调节的相互耦合和不利影响，提出将环流信号引入有效值调节环路，有效地改善了并联系统的均流特性和稳压特性。理论分析和实验结果证明了控制方法的有效性和工程可实现性。     

水工业的节能降耗必须与自动化集成紧密交融

从四十多年工程设计及管理实际经验出发,总结出水工业在采用变频调速、节能降耗的高新技术时必须要解决的关键技术问题,如寻找综合理想的水泵特性曲线,选用最佳的调速方案,制造最理想的网络监控环境等。针对这些应用中的技术问题,提出了见解。     

变频器供电对异步电机绝缘系统可靠性的影响

与电网供电相比，变频器供电的异步电机绝缘系统承受了更高的应力，因而有必要以新的标准对变频电机的绝缘系统进行重新考虑。分析了变频驱动对电机绝缘系统的影响。并在此基础上提出了改进措施。     

An overheating‐tolerant space vector modulation algorithm for multilevel inverters

As promising and suitable candidates for high‐power applications, multilevel inverters have become one of the most promising solutions in various applications. However, power switching devices are highly subjected to thermal overheating, which leads to shortened lifetime and reduced reliability. Thermal overheating may result from the degradation of power switching devices due to continuous overloading and power cycling. In addition, degradation and faults in the cooling system of power switching devices may cause thermal stresses as well. A new overheating‐tolerant space vector modulation algorithm is proposed in this paper to alleviate thermal stresses from overheated power switching device. The proposed algorithm relies on using the redundancy property between switching states in multilevel inverters to continuously evaluate a cost function of the junction temperature of the overheated device for all possible switching sequence sets and then selects the optimal switching sequence. In addition, the proposed algorithm preserves the DC‐link capacitor voltage without reduction in the output current of the inverter. The proposed algorithm is general, which can be applied to n‐level inverters. Both simulation and experimental results reveal the efficient performance of the proposed algorithm using a three‐level T‐type inverter as a case study. Accordingly, the lifetime and reliability of the inverter are enhanced considerably using the proposed algorithm. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Commander SK变频驱动器在摆频控制中的应用

根据纺织摆频的特性,结合CT公司的Commander SK变频器所具备的独特的功能,对Commander SK变频驱动器在纺织摆频控制上的应用进行了研究,并找到一种简单可靠的摆频控制解决方案。     

浅谈给粉机变频调速

变频调速可靠性高,调速性能优越,随着变频器价格的下降,给粉机使用变频器调速已经成为可能。下面就结合车间三台锅炉24台给粉机的实际情况谈一下笔者对变频给粉机的认识。     

新型载波移相同步脉冲发生器的研究

提出一种新型载波移相同步脉冲发生器。该发生器基于工业以太网分布时钟,可以产生纳秒级的高精度同步脉冲信号,信号用来同步链式多电平逆变器所有阀体输出的PWM脉冲。该控制系统成功应用于10 k V/1 Mvar级静止同步补偿器（STATCOM）装置。     

Seamless Transfer Control Strategy for Grid-Interactive Inverters

Abstract—Single-phase microgrids are widely used in residential houses. The energy storage system with grid-interactive inverters in these microgrids should operate in both grid-tied and standalone modes. In this article, proportional resonant controller for the single-phase grid-interactive inverter with LCL-filter is designed and implimented in the both operation modes. Also, a novel seamless transfer strategy based on hysteresis current control is proposed when off-grid transfer operation is needed. With the proposed method, the inverter is able to provide voltage support to the local critical loads during the whole transfer process when the grid fails. For the grid-tied transfer process, a phase difference eliminating method based on inverter frequency regulation is introduced in this article to eliminate the phase difference between the grid voltage and the inverter voltage when the grid recovers. Simulation and experiments are carried out and the results verify the effectiveness of the proposed control method.     

圆盘剪机列电气控制系统的改造

介绍PLC、直流全数字调速装置及交流变频调速器在钛板圆盘剪机列电控系统上的应用。