共查询到20条相似文献，搜索用时 218 毫秒
1.
何跃军 《深圳职业技术学院学报》2014,(5):8-12
介绍一种基于主从控制方式、采用无刷直流电动机驱动、中型电动车驱动控制器的设计方案,以及驱动系统的总体构成、主电路与驱动电路的设计原理、参数设计方法和主、从控制板通信原理.阐述了系统母线电流检测电路、蓄电池电压检测电路的设计原理,以及系统母线电流保护电路、蓄电池电压保护电路、启动加速预警保护等多种保护电路的设计方法.试验表明,该驱动控制系统制造成本低、调速控制性能好,保护措施完善,达到了设计目的. 相似文献
2.
马占标 《淮南职业技术学院学报》2007,7(1):35-36,40
用单片机AT89C52完成对电动机断相、过流、短路、接地、低电压、过电压、起动时间过长等故障的保护,当出现上述任何一种故障时,系统在进行处理和判断后,发出跳闸报警信号,并显示故障信息,从而提高了保护的可靠性。 相似文献
3.
马汝星 《金华职业技术学院学报》2006,6(1):4-6
研制以P87LPC768单片机为核心的电动代步车智能控制器,具有过流、欠压保护及调速电位器、和刹车故障保护及报警功能。经试车运行表明该控制器运行平稳、可靠性高。文中介绍了控制器的软硬件设计。 相似文献
4.
Vacuum interrupter, high reliability component of distribution switches, circuit breakers and contactors 总被引：1，自引：0，他引：1
SLADE Paul G LI Wang-pei MAYO Stephen SMITH R. Kirkland TAYLOR Erik D 《浙江大学学报(A卷英文版)》2007,8(3):335-342
The use of vacuum interrupters(VIs)as the current interruption component for switches,circuit breakers,reclosers and contactors operating at distribution voltages has escalated since their introduction in the mid-1950’s.This electrical product has developed a dominating position for switching and protecting distribution circuits.VIs are even being introduced into switching products operating at transmission voltages.Among the reasons for the VI’s popularity are its compactness,its range of application,its low cost,its superb electrical and mechanical life and its ease of application.Its major advantage is its well-established reliability.In this paper we show how this reliability has been achieved by design,by mechanical life testing and by electrical performance testing.We introduce the“sealed for life”concept for the VI’s integrity.We discuss this in terms of what is meant by a practical leak rate for VIs with a life of over 30 years.We show that a simple high voltage withstand test is an easy and effective method for monitoring the long-term vacuum integrity.Finally we evaluate the need for routine inspection of this electrical product when it is used in adverse ambient environments. 相似文献
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杨建湘 《广西梧州师范高等专科学校学报》2014,(2):143-146
介绍了一种用于织物表面处理常压低温等离子体电源的工作原理及控制方法。根据纺织物表面处理工艺要求,高压电源采用前级PWM控制Buck电路DC／DC变换,后级H桥逆变经变压器升压结构产生稳定、均匀、柔和的低温等离子体。自动调节以计算机为控制单元,利用传感器技术实现自动控制,提高电源的可靠性。实际应用等离子体高频高压电源在纺织材料中的结果表明：该技术在提高了电源效率的同时,快速有效地抑制浪涌电压和峰值电流,改善了纺织材料表面处理的性能。 相似文献
7.
Research on the overload protection reliability of moulded case circuit-breakers and its test device 总被引：1，自引：0，他引：1
LI Kui LU Jian-guo WU Yi QIN Zhi-jun YAO Dong-mei 《浙江大学学报(A卷英文版)》2007,8(3):453-458
This paper analyzed the reliability and put forward the reliability index of overload protection for moulded case circuit breaker. The success rate was adopted as its reliability index of overload protection. Based on the reliability index and the reli- ability level, the reliability examination plan was analyzed and a test device for the overload protection of moulded case cir- cuit-breaker was developed. In the reliability test of overload protection, two power sources were used, which reduced the time of conversion and regulation between two different test currents in the overload protection test, which made the characteristic test more accurate. The test device was designed on the base of a Windows system, which made its operation simple and friendly. 相似文献
8.
赵渝青 《温州职业技术学院学报》2003,3(4):36-37,40
本文提出了设计一种应用电磁感应加热、高效率、水电完全隔离、安全的即热式电热水器的主要构思，并说明了该热水器中功率及驱动电路、检测与功率调节电路及保护电路的主要设计思想和部分有关问题的解决方法。 相似文献
9.
刘鹏 《河北能源职业技术学院学报》2012,(1):64-66
针对洗煤厂耙式浓缩机频发电气短路事故导致全厂急停车,使煤泥设备跑水,运输设备被煤压住,恢复生产所需时间长,严重制约生产效益的问题,对循环水系统增加液位监控,自动变频排水,增强滑环绝缘强度,浓缩机高度异位报警,查找供电线路保护失效烧毁元件的原因针对性的选择电气保护开关并加装漏电断路器等改进方法,缩小故障范围,减少电气元件的损坏,解决耙式浓缩机电气事故频发问题,避免了事故导致全厂长时间停产,确保洗煤生产的正常进行,增加了生产效益。 相似文献
10.
在电源主电路中利用三极管集电极-发射极间的等效电阻作为LM317调节端可变电阻,解决了宽范围输出电压源中运算放大器需要较高电压供电的问题,并采用二档自动调节LM317输入电压的方法和电感负载保护电路,降低了故障率;以8位微控制器AT89S52为核心构成串级控制系统,提高了输出电压的响应速度和控制精度;设计了LCD实时显示和键盘、编码器输出电压设定电路,操作方便,减少了操作时间,适应了实验教学需要。 相似文献
11.
卜向锋 《河北能源职业技术学院学报》2012,(3):56-57
鉴于煤矿井下供电系统在煤矿安全生产中的重要作用,矿用隔爆型低压馈电开关的保护装置显得尤其重要,通过对低压馈电开关保护器漏电保护电路改进,对零序电压及零序电流的相位关系来定性确定是本回路发生漏电还是其他回路发生漏电,利用附加直流原理来定量确定绝缘电阻值是否降低到动作规定值,通过在煤矿井下的使用取得了较好的效果,值得推广使用。 相似文献
12.
Reliability of substation protection system based on IEC61850 总被引：1，自引：0，他引：1
Although the new technology of protection and automation system of substation based on IEC61850 standard has developed rapidly in China, reliability measures depending on this technology need to be further research＇ed. By taking advantage of convenient information sharing, two kinds of new schemes, shared backup protection unit （SBPU） and signal backup （SB）, have been proposed to solve the failure problem of protective devices and current/voltage transducers respectively, and the working principle of these two schemes are also described. Furthermore, the key technologies of on-line diagnosis of protective devices＇ failure and on-line status diagnosis of optical or electronic current/voltage transducers to realize the two schemes are proposed. 相似文献
13.
介绍了一种将可控硅调整与晶体管串联稳压电源有机地结合在一起、输出电压连续可调的高压大功率直流稳压电源。该电源不仅具有输出纹波小、输出特性好、瞬时响应快等线性电源的优点,还具有调整管的管压降小、可靠性高、使用方便等特点,可作为高压铝电解电容器充电测试的高性能电源而用于自动分选机中。 相似文献
14.
LU Na XU L.J Miedzifiski B 《浙江大学学报(A卷英文版)》2007,8(3):393-396
Undesirable repulsive force between contact members due to both a current path shrink near a real contact area and/or so-called pinch effect is particularly onerous for power switch applications, and results in either contact floating or bouncing which are associated with an electric arc following contact welding. This problem is of great importance for any circuit breaker especially for compact low voltage vacuum circuit breakers. To avoid contact floating at closure and during any inrush current under short circuit conditions, the electrodynamic repulsive force can be employed successfully if we use a special compensation system flexibly combined with the contact itself. However to select and design the compensation system properly, its efficiency has to be known. This paper presents an approach to obtain the electrodynamic force value depending on different shaped (rectangular, square, circle and arch) copper plates used in the compensator by using ANSYS for current values 40 kA RMS. Curve-fitting was done according to the calculating results, the optimization designing of compensation unit is based on them. 相似文献
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SA Peng-fei ZHAO Min FANG Shu-hua 《重庆大学学报(英文版)》2006,5(1):19-23
1 Introduction [1-3]The permanent magnetic actuator (PMA) technology first showed up in 1990s. It adopts a new working theory and a novel structure. With the combination of electrical magnetism and permanent magnetism, it can realize all functions of a br… 相似文献
17.
杨飒 《广东教育学院学报》2003,23(2):35-37
利用反馈元件与电路输入、输出端的连接方式,来简化反馈类型的判别过程,并根据电压和电流的相互转换关系,采用“瞬时电流法”判别反馈电路的性质．通过对四种反馈电路的分析,来证明该方法的可行性和优越性． 相似文献
18.
侯学峰 《河北能源职业技术学院学报》2008,8(3):67-69
目前在10kV及以下电压等级配电网络中,真空断路器已逐步取代油断路。在无油化改造过程中发挥了积极作用。但使用过程中也应注意几个问题,使它的优越性得到充分发挥。 相似文献
19.
常辉 《兰州石化职业技术学院学报》2012,(3):10-12
石化厂丙烯腈变低压进线控制回路采用三相低压继电器,单触点触发的控制方式来实现备自投动作;时间继电器为断电延时。在全所失电时,会出现来电跳闸的情况,延误系统恢复时间,影响供电质量。基于对低压进线控制系统的分析,阐述了低电压继电器及时间继电器选取的重要意义,将进线柜内的三相低电压继电器更换为三个单相低电压继电器,时间继电器选为通电延时型。通过对控制系统的改进,缩短操作人员的系统恢复时间,提高了供电系统的稳定、可靠性。 相似文献
20.
真空断路器的绝缘性能 总被引：1，自引：0，他引：1
叶永卫 《黄冈职业技术学院学报》2009,11(3):27-28
对真空断路器的电气性能进行分析,找到了影响真空断路器绝缘性能的原因,提出了一些提高真空断路器的绝缘性能的办法。提高真空断路器的绝缘性能,有助于它在高电压使用领域发展,也利于输电系统的运行。 相似文献