基于交—交变频器的同步电机矢量控制算法研究

交交变频同步电机矢量控制系统在风电、冶金等行业的应用日益广泛。本文主要对矢量控制算法中的磁链电流模型、磁链电压模型、功率因数控制、磁链调节与弱磁控制等主要环节的原理及实现方法进行了阐述,并用实验验证了利用交—交变频器实现电机矢量控制能够实现调速性能的优化。     

变频及软启动在恒压供水系统中的应用

本文分析了一般供水系统中存在的问题，阐述了采用交流变频调速结合软启动器控制方案的经济性优越性。介绍了变频器和软启动的控制原理及系统御，给出了运行结果。     

变频调速技术的原理及应用

变频技术主要用于交流电动机转速的调节,是交流电动机最理想、有发展空间的调速装置,具有卓越的调速性能和显著的节能作用。本文就变频器的调速节能原理、变频器的常用功能以及变频器的控制方式,进行了综合分析,结果表明变频器是企业技术改造和产品更新换代的理想调速装置。     

变频及软启动在恒压供水系统中的应用

本文分析了一般供水系统中存在的问题 ,阐述了采用交流变频调速结合软启动器控制方案的经济性和优越性。介绍了变频器和软启动的控制原理及系统特点 ,给出了运行结果。     

中央空调为何要使用变频器

本文简要介绍了变频器节能原理，实际使用实例，三种变风量系统，变风量控制优缺点及其采用温度闭环系统变频器节电效果显著。     

交流变频器应用中的一些体会

通过介绍变频器的发展，使人们对变频器有一定的认识，然后进一步阐述变频器的控制原理，以及对变频器节能进行剖析，使人们能够更好合理经济的利用能源，带来更大的经济效益。     

交流变频器调速和节能综述

本文简述了交流变频器调速的基本工作原理，并了十六家企业使用变频器后的节能效果，提出了庆大力普及，推广变频器的建议，为国家节约宝贵的能源。     

交流变频调速器和节能综述

本文简述了交流变频器调速的基本工作原理，并综述了十六家企业使用变频器后，其节能效果，提出了应大力普及，推广变频器的建议，为国家节约宝贵的能源。     

变频器在锅炉风机中的节能应用

本文论述了变频器在锅炉风机中的节能应用，给出了节能原理和控制系统图，锅炉风机采用变频控制，节能显著。     

交流变频调速异步电动机节能计算方法探析

异步电机的电流大小和电机消耗的功率随负载的轻重而改变,利用电磁调速、恒转矩负载等节能方法,对变频异步电动机节能进行了估算,分析采用变频器对交流异步电动机进行调速控制,可以节省可观的电能.     

Using power ultrasound for the regeneration of dehumidizers in desiccant air-conditioning systems: A review of prospective studies and unexplored issues

Regeneration of dehumidizers is the most important stage in the working cycle of desiccant system. The lower regeneration temperature will be favorable for the energy efficiency of the whole system. Ultrasonic technology may be a promising method of dehydration applied to the regeneration of desiccant. As a non-heating method, the power ultrasonic may help lower the regeneration temperature and bring about energy savings. In the present paper, the mechanism of ultrasonic regeneration is set forth based on the ultrasonic theory as well as the mass transfer model in solid–gas and liquid–gas system. The recent studies related to ultrasonic dehydration are extensively reviewed, which is of significant reference to the study of desiccant regeneration assisted by power ultrasound. In addition, this work gives the basic ideas of ultrasonic dehydrator for solid/liquid-desiccant regeneration, which will promote the development of relevant equipments. Finally, some unexplored issues on this topic are addressed, including insight into the effects of ultrasonic on the regeneration, drying kinetics model for ultrasonic regeneration and the challenges possibly faced for the ultrasonic transducer development.     

柴油机电控系统的转速测量技术研究

分析了差分霍耳传感器的工作原理,介绍了利用差分霍耳传感器实现转速测量的理论基础和实用电路。     

变频调速节能技术在龙门刨床上的应用

就传统龙门刨床使用直流发电机组拖动控制,改造为采用交流变频调速与PLC控制进行深入探讨,并在实践中应用,运行结果表明:采用变频调速控制技术可大大提高龙门刨床的加工能力,超出原有技术指标,同时还能获得明显的经济效益。     

Exergy-based control of electricity demand and microgeneration

As the penetration of weather-dependent embedded generation grows, the variations in apparent demand experienced by distribution network operators will become more extreme. A method for the autonomous control of domestic electricity demand and microgeneration is proposed using the established, but underdeveloped, radio teleswitch technology. The disadvantages of cost or carbon-emission based optimisation using this method are discussed and an alternative approach based on minimisation of exergy loss is described. Results obtained from a computer model demonstrate its potential contribution to the balancing of electricity supply and demand.     

An intelligent discontinuous control strategy for hydroelectricgenerating unit

An intelligent discontinuous control strategy for water turbine regulation is presented in this paper. Taking reliability and the static and dynamic performance of the system as the ultimate goal, it combines the classical fuzzy control theory and tri-state valve technology to form a discontinuous controller. This results in a simplified water turbine governor, both in software and hardware. The proposed control strategy greatly improves system performance and reduces the cost by totally eliminating the electro-hydraulic transducer. Simulation results show it has a satisfactory performance     

涡流法判断铝硅合金活塞变质效果的方法

铝硅合金变质前后组织中共晶硅的形态发生明显变化,导致材料电导率改变,应用涡流传感器采集不同变质效果的试块或活塞的电信号,信信号的大小可判断铸件的变质效果。     

针对并网型风储微网的飞轮储能阵列系统控制方法CSCD

由于新能源发电存在波动性和间歇性,其大量接入时会给电网运行带来新的困难,而利用储能技术提高新能源的可调度性是当前研究的热点。为缓解新能源并网对电力系统的不良影响,针对并网型风储微网提出了一种基于飞轮储能阵列系统的分层优化控制方法,上层优化中心根据功率缺额和各台飞轮的转速建立相应充/放电优化模型,并求解相应飞轮的功率参考值;下层飞轮控制器采用双模双环控制方法,实现飞轮转速和输出功率的控制,最后通过MATLAB/Simulink仿真验证了所提控制方法的有效性和可行性。     

爆燃传感器的工作原理与控制

本文介绍了爆燃传感器的工作原理、安装方法以及振动信号的传输。同时提出了爆燃控制原理、爆燃信号的采集及处理方法。     

Simulation of ultrasonic phased array technique for imaging and sizing of defects using longitudinal waves

Phased array ultrasonics can be used as a rapid tool for imaging and sizing crack-like defects. This paper reports the simulation of phased array ultrasonic wave interaction with the defects using the finite-difference time domain (FDTD) method. Experiments were conducted to validate modeling results for pulse–echo simulations of the phased array transducer on a mild-steel (MS) pipe sample with circumferential internal surface notches of three different sizes. Experiments were carried out on the MS pipe specimen using a conventional ultrasonic technique with a 5 MHz transducer at 45° refracted angle within the specimen and the defects were imaged and sized using the relative arrival time technique (RATT). The experimental B-scans obtained using the conventional ultrasonic techniques were compared with the experimental B-scans obtained using the phased array instrument. Simulation studies were also carried out by steering the beam to the requisite angles by the phased array transducer to study the effect of various angles of incidence on the defect definition, i.e., with respect to imaging and sizing, using the RATT.