通信交流供电方案初探

在通信供电系统中,与直流供电系统相比,从设计、设备技术,到运行维护管理,交流供电系统都有所滞后。借鉴直流供电系统经验,通过应用N X并联逆变器模块热插拔技术,实行分散式供电,进而改变传统的以UPS为核心的集中供电模式,则可在很大程度上解决一直困扰着我们的交流供电系统成本高和可靠性低的难题。     

可并联逆变器中的同步控制技术及其实现

论述了可并联逆变器中的同步控制技术及其实现方法。在分析了同步的重要性之后，提出了抢占与并发相结合的同步控制策略及其实现方法，实践证明该方法具有很高的控制精度。     

中压变频器在宣钢炼钢厂除尘风机中的应用

本文介绍了SIMOVERT MV中压变频器在宣钢炼钢厂一次除尘风机中的应用情况。变频器现场运行表明，采用中压变频器对转炉除尘风机进行调速节能获得了成功，节能效果明显。     

Evaluation of a proper controller performance for maximum-power point tracking of a stand-alone PV system

In this paper the implementation of a suggested stand-alone PV system, for maximum-power point tracking (MPPT), is carried out. Also, this paper presents a comparative study, through experimental work, between the conventional PI controller and the fuzzy logic controller (FLC) under different atmospheric conditions. The implemented system with both the PI controller and the FLC gives a good maximum-power operation of the PV array, but the tracking capability for different optimum operating points is better and faster for the case of using the FLC compared to the case of using the PI controller.     

Transient analysis of an advanced static var compensator using quad-series voltage-source PAM inverters

This paper deals with an advanced static Var compensator (ASVC) using quad-series voltage-source PAM inverters. The ASVC consists of four three-phase voltage-source inverters with a common dc capacitor and four three-phase transformers, each primary winding of which is connected in series with each other. Each inverter outputs a square-wave voltage, while the synthesized output voltage of the ASVC has a 24-step wave shape. This results not only in a great reduction of harmonic currents and dc voltage ripples but also in fewer switching and snubbing losses. In this paper, transient analysis is performed with the focus on the response of reactive power and the resonance between the dc capacitor and ac reactors. Experimental results obtained from a small-rated laboratory model of 10 kVA are also shown to verify analytical results based on the p-q transformation. The analytical results help in the design of system parameters such as the capacity of the dc capacitor and feedback gains.     

Means of enhancing and promoting the use of solar energy

The development of renewable technologies in the last decade has been exceptional. In photovoltaic (PV) for example, efforts were not only limited to merely improving their efficiency but also to the reduction of the cost of cells and modules via volume production for commercial markets. There are many national schemes promoting the use of PV technology and regional targets for a share of renewable energy production. This paper attempts to relay to the reader a journey, based on experience, approaches for enhancing the prospect of utilising solar energy within the society we live in. The issue of expansion or enhancing the utilisation of solar energy can be undertaken by individuals, groups, institutions and governments. The aim of this paper is to provide some examples, which could serve as a framework in which action could be taken to promote solar technology.     

PLC在环锭捻线机上的应用

介绍了如何使用PLC和数字变频调速技术 ,对传统环锭捻线机进行技术改造 ,使锭速、捻度和卷绕成形变换实现数字化柔性控制 ,扩大了工艺参数的变化范围 ,使整个捻线加工车间实现信息化管理成为可能。     

交流变频调速技术在二辊轧机压下系统中的应用

介绍一种采用变频调速技术控制的二辊轧机压下系统。该系统可控制轧机压下系统的速度在工艺要求的范围内无级可调，压下量以数字动态显示，控制准确、操作方便。文中对系统的组成及工作原理作了较详细的介绍。     

台达变频器在纺织织带盘带机上的应用

盘带机是纺织织带成品分卷设备，需要使用到收放卷控制。本文基于台达变频器在盘带机上的应用案例，论述盘带机自动化系统设计调试过程以及遇到的问题分析。     

Present status and future prospects of PV activities in Japan

The photovoltaic (PV) power systems in Japan made great strides in the past decade. The PV industry in the 1990s greatly depended on the research projects and dissemination programs carried out by the Ministry of International Trade and Industry. However, the industrial structure for full-scale deployment of the PV system is currently being established by the manufacturers’ continuous efforts to reduce the PV system cost and the government’s consecutive supports to create the initial market. It is expected that the synergetic effect of the cost reduction and incentives for introduction will activate the PV industry and its market more and more toward achieving 5000 MW of the capacity in FY 2010.