1 Working principle of distance protection
Distance relays use voltages and currents acquired at the relay location to calculate the apparent impedance of the line from relay point to the fault point. The calcu- lated apparent impedance Z is compared with the set- ting impedance Zset to decide whether the fault is inter- nal or external. During normal operation, the apparent impedance is generally larger than the Zset. If the apparent impedance is less than Zset, then it is concluded that a fault has probably occurred in the protected line. Under fault conditions, the distance relay energizes the circuits to trip relevant circuit breakers to isolate the faulted line from the rest of the system[8].
Fig.1 shows the working principle of distance protection. The startup element starts protection devices or fault calculating programs when fault occurs in the pro- tected line. The measuring element, which is the center of distance protection, calculates the line impedance between the fault point and relay point. The time delay element determines different time delays according to the result of the measuring element. The output element executes the decision of protection.
2 Configuration of simulation system
The dynamic simulation system for distance protec- tion proposed in this paper is designed according to its working principle and elementary configuration. As shown in Fig.2, the simulation system is composed of electromagnetic transient computing module, PT & CT module, data reading module, U & I display module, startup module, Fourier algorithm module, phase selec- tion module, impedance computing module, impedance comparison module and so on. In this closed-loop simu- lation, the relay trip signal is fed back to control the cir- cuit breaker of power system model. This closed-loop simulation approach has greatly enhanced the accuracy of simulation and made it possible to simulate the dynamic interactions between power systems and protection systems.
2.1 Fault transient computing based on PSB
The PSB was designed to provide a modern design tool that will allow users to rapidly and easily build models that simulate power systems. The blockset uses the Simulink environment, allowing a model to be built using simple click and drag procedures.
The libraries contain models of typical power equipment, such as transformers, lines, machines, and power electronics. These model’s validity is based on the experience of the Power Systems Testing and Simulation Laboratory of Hydro-Québec, a large North American utility located in Canada.
Matlab and its time domain solver Simulink create a friendly and open system. New models and libraries of power equipments may just be added to this package. In this developing environment, we can finish all kinds of power system simulations[5—7]
希望专业人士给回答下,以上的翻译都是用软件翻译的,什么PSB 被翻译成公安局,印尼,国际米兰都来了,很不地道。我自己已经翻译完了可有些语句表达不顺畅,望高手好好解答,谢谢了
电气英文翻译,论文的部分-看不懂,还请高手帮忙
If the apparent impedance is less than Zset, then it is concluded that a fault has probably occurred in the protected line.如果明显阻抗小于Zset ,那么得出的结论是有可能发生故障的保护线。 Under fault conditions, the distance relay energizes the circuits to trip relevant circuit breakers...
英译汉,一段英文论文,看不太懂,请高手帮忙翻译下,不胜感激!
Electronic Commerce on the New Silk Road: A Cornucopia of Research Opportunities 新丝绸之路电子商务:丰富的研究机会 The Silk Road was an important trade route between Europe and Asia a thousand years ago.千年以前,丝绸之路是欧洲和亚洲之间重要的商贸路线 It connected locations in Central ...
求高手帮忙翻译下面几段的电气专业英语。。。谢谢了
7 Unbalanced Faults 不平衡故障 A very common application of symmetrical components is in calculating currents arising from unblanced short circuits. For three-phase systems, the possible unbalanced faults are:对称部件的一个常见应用是在计算不平衡短路产生的电流。对于三相系统,可能的不平衡故障...
求英语高手帮忙翻译一段电气方面的英语课文
对任何电气系统的重要组成部分,是连接所有的电线连接的components.the布线可以分为三个部分:1,服务的入口:这些是提供从供电系统的能量被服务单位的导体。导体是他们的入口点附近将终止在装备建设服务。这项服务是主要的控制设备和手段根据供应截止。在一个大的前提的情况下,电力通常是由电力公司提供在中...
电气专业英语翻译!高手帮忙!
4)公共汽车平分优势iselectrically联锁电路断路器,所以它既可以不封闭除非一个人引用的断路器是开着的。5)当一个引用的料,380V公共汽车旅行平分优势是关闭的,自动延迟行动利用其他来料机是可载整个负荷电流及开关设备能力足够提供参考。6)自动转380V系统临界负荷值则会加载在柴油发电机当停电时在公共汽车...
电气专业英语翻译!高手帮忙!Voltage stability
(2)小扰动下的电压稳定性是指系统在受到小的扰动时,譬如系统负荷的小幅增加,系统控制电压的能力。这种能力是由负荷特性,连续控制和某指定时刻的离散控制来决定的。一个衡量小扰动下电压稳定性的标准是不论系统的哪一个节点,当给该节点注入无功功率时,其电压幅值会随之升高。若系统中至少有一个...
电气英文高手帮忙:Limits for harmonic current emission..._百度...
极限为泛音当前的emission(equipment 当前的s 16.A 每阶段)
哪位高手帮忙翻译一下这段电气方面的材料~!不胜受恩感激!
Using hybrid packaging technology, seven unit in traditional three-phase full bridge main circuit, using 1200 v \/ 1200 a IGBT and FRD tube core, integrated a complete reversible power circuit, drive and protection circuit, control circuit and current sensing hopefully, adopts digital ...
英文简历给外企的有好多地方不明白高手帮帮忙,线上等,之后还追分
急:英文简历,有些地方不会翻译,英文高手帮忙~~ 你的回答我已看到,我主要看你帖子挂了好多天,没有满意答复,所以征求下你的意见,现我已翻好,质量可以保证,请明鉴。 1.熟练运用UG软体进行实体建模,并熟悉结构分析及运动分析模组(可提供相关作品) 1.Be proficient in using UG sofare to carry out solid model...
高手帮忙找篇外文---论文的外文翻译要用,,急。
高手们,帮我找个关于:“商业街或步行街”的外文的文章。要有作者的。然后在帮我翻译下(要求3000以上哦)。对了,别用翻译工具或网业翻译,要好点,呵呵。本人的全部分数将全部奉上... 高手们,帮我找个关于:“商业街或步行街”的外文的文章。要有作者的。 然后在帮我翻译下(要求3000以上哦)。对了,别用翻译...