可用于50Hz和60Hz的高压开关设备的型式试验对频率的要求

当中国的高压开关设备出口到使用额定频率60 Hz电网的国家和地区时,该产品需要满足额定频率60 Hz系统的型式试验要求。虽然相关IEC标准对高压开关设备在50 Hz和60 Hz下的型式试验已有明确要求和方法且STL导则也进一步明确了具体试验中的要求,但是为了更容易确定在这两种频率下的型式试验项目,笔者经过研究相关标准对型式试验进行了详细归纳。并对高压开关设备在50 Hz和60 Hz下的某些型式试验做了试验参数的可行性分析。结果表明:除温升试验、试验方式T60、T100s(T100s(b))、T100a、近区故障试验和容性电流开合试验外,其他型式试验在50 Hz或60 Hz下进行均可。这就为产品制造商节省了大量的试验时间和资金。     

用50Hz电源完成60Hz电机试验

我国的工频电源为50Hz,但欧美地区一些国家的工频电源都是60Hz,所以要求出口电机的额定频率也是60Hz,这就给电机性能试验带来一定的困难。我厂在试验室现有的条件下完成了出口电机的型式试验及出厂试验。我厂于1982年安装一套35kW变频机组,当时考虑是作为50Hz电机负载试验反馈用的,若作为电源机组用,同步机发出的电源频率只能达到55Hz,达不到60Hz,我们通过对机组励磁回路进行改造,     

60Hz电气设备在50Hz电网中的应用

文章讨论额定频率60Hz的异步电动机、变压器及低压电器应用于50Hz电网时可能出现的问题和解决办法。     

50Hz/60Hz频率互换对不同电气元件的影响

正各国的电网存在一致性和差异性。例如,在监理菲律宾电站项目时,其国家电网频率为60 Hz,故而对我国提供的设备、柜体、附属元件要求必须满足60 Hz要求,而我国电网频率为50 Hz,许多中小型设备供应商无法每个环节都控制的特别严谨,给项目的验收工作带来许多困难。在设备的质量验收过程中,涉及频率要求的一系列问题,给很多人带来疑惑。所以结合自己的一些见解,针对50 Hz与60 Hz元     

交流接触器60Hz线圈参数设计

交流接触器50Hz与60Hz产品通用,这在各相关产品标准上均作了阐述,仅对控制电路方面50Hz与60Hz交流接触器线圈的通用性和参数换算以及电校方法作一介绍。     

静止式60Hz标准电源

我所研制成功了一种静止式60Hz标准电源,可供有关工厂、商检部门、产品质量认证中心和科研单位作为60Hz电器产品的试验电源使用。该系列电源的主要功能指标如下: 1.输入电源:三相四线,50Hz,相电压220V±10%。 2.输出参数: 电压:单相220V、110V或用户指定电压 频率:60Hz±0.l% 波形:正弦波、失真度<5%(一般达3%) (符合国家标准GB1032—85要求) 电压调整率:<±2%(额定输入电压下,负载从10%增至100%) 电压稳定度:<±0.5%(在额定输入电压及75%负载下,8小时)     

《电力设备》市场版诚邀撰文投稿

概述。VS1户内交流高压真空断路器是一种整体式全封闭型，体积小、结构紧凑的高压开关设备。它适用于三相交流50Hz．额定电压12kV的电力系统中．作为线路及电气设备的控制与保护之用。并可用于频繁操作的场所。产品符合GB1984，JB3855以及DL403等相关标准之规定。     

用于60Hz电力系统的高压直流换流阀运行试验等效方法

为保证高压直流(HVDC)工程能够可靠运行,必须进行换流阀运行试验,而运行试验回路工作频率受制于电力系统的频率,如何对不同频率下的产品进行试验是亟待解决的问题。为满足60Hz电力系统的换流阀运行试验要求,以西安高压电器研究院50Hz频率的换流阀运行试验回路为基础,对换流阀的最小单元晶闸管级的结构、运行中各种过程、晶闸管级承受的电流和电压等电气参数及损耗特性进行了研究和比较,提出了进行60Hz换流阀运行试验的等效方法和折算系数。研究结果表明,在1种运行试验回路上进行不同频率的换流阀运行试验的方法可行,但需要根据不同的试验项目进行适当等效折算,以达到试验检测的目的。该方法的提出可为在世界范围内适用不同频率的直流输电工程的研究、检测等工作提供指导和参考的作用。     

XGN20-12型户内交流高压SF6环网开关设备

XGN20-12型户内交流高压SF6环网开关设备是由上海德力西集团有限公司生产的，以SF6负荷开关作为主开关的金属封闭开关设备。该产品整柜空气绝缘，结构紧凑，操作灵活方便，联锁可靠，主要用于三相交流额定频率50～60Hz、额定电压12kV的环网供电或双辐射供电系统，作为电路的控制和保护装置。该装置特别适用于小型二次配电站、箱式变电站、开闭所、工矿企业、城市居民小区、机场、医院、铁路、隧道、高层建筑等场所。     

60Hz电机用于50Hz电源的性能分析与改造方案

分别从理论与实践两方面论述60Hz电机用于50Hz电源时的要求与方法,并对电机的运行性能进行了分析,得出一些实用方法.     

Design considerations for powering 415 Hz computer systems

It is noted that the design of 415 Hz power systems for mainframe computer systems requires additional considerations beyond those of conventional 60 Hz systems. The effects of the higher frequency on the wiring, components, and power system design are explored. Voltage drop, line drop compensation, centralized versus distributed power sources, and the special requirements of typical mainframe computer systems are considered. The power quality requirements of 415 Hz computer systems are significantly different from those of 60 Hz computer systems. The steady-state voltage tolerance is generally much tighter while the frequency tolerance is much broader. Because of the effects of the higher frequency on wiring impedance, 415 Hz wiring practices are different from those for a 60 Hz system. Nonmetallic or nonferrous wireways and relatively short wiring runs are recommended. Wire sizes larger than #2/0 are not effective at reducing wiring voltage drop, parallel conductors in parallel conduits are recommended. For best results, multiconductor cable assemblies such as the seven-conductor 400 Hz cable are recommended. Both passive and active line drop compensation techniques are available to help offset wiring voltage drop. Centralized 415 Hz power sources offer the advantages of economies of scale and ease of redundancy, which having the disadvantages of complicated 415 Hz wiring system design, higher installation costs, lack of flexibility, and potential load interactions. Distributed 415 Hz power sources minimize 415 Hz wiring and make it easier to meet the computer system's power requirements     

Harmonic response tests on distribution circuit potentialtransformers

Experimental data are presented that show the performances of distribution circuit potential transformers operating with nonsinusoidal waveforms. Four standard magnetic voltage transformers designed for 60 Hz power applications and rated from 7.2 kV to 20 kV were tested. Ratio correction factor and phase angle measurements were conducted at rated 60 Hz voltage with harmonic distortion levels at and below 8%. Test results indicate that potential transformers rated up to 20 kV experience errors of less than 5% at harmonic frequencies up to 3500 Hz when operating into typical induction watthour meter burdens. The phase angle response is essentially linear over the frequency range used to test the transformers, with a typical phase angle of about -10° at frequencies of approximately 3 to 3.5 kHz     

400Hz中频单相电压源逆变器的输出控制及其并联运行控制

中频电源由于其较高的输出频率，要想得到较好的输出电压波形和较大的输出功率，则比工频逆变器的控制更加困难。针对400Hz中频逆变器的特点，给出了一种带幅值环的双闭环单相逆变器控制策略，得到了很好输出波形。并提出了一种介于有线和无线并联控制方法之间的共享同步信号的外特性下垂控制方法，以及用于消除直流环流的直流偏置电压下垂方法，将上述方法应用于中频逆变电源的并联运行控制，取得了很好的均流效果。介绍了该方案的理论依据，并搭建了两台1.5kW的实验样机，实验结果证明了该方案的有效性。     

基于DSP150V/50Hz高品质单相逆变电源的设计

针对某型导弹供电电压精度高、频率波动小的特殊要求,采用TMS320LF2407A型DSP为主控芯片、全桥逆变智能功率模块(IPM)为主电路、SPWM为控制方法研制了一个150 V/50 Hz高品质单相逆变电源.应用积分分离式数字PID调节器提高了电源动态响应速度和输出电压的品质,使得电源在额定负载(15 A)时,输出电...     

The evolution of power-line frequencies 133 1/3 to 25 Hz

It is generally understood that 60 Hz as frequency of AC power, has not always been that number. 60 Hz resulted after several trials of values for AC frequency, each determined by different criteria. This article presents a brief overview of the various frequencies beginning with 133 1/3 Hz and traveling through 125, 83 1/3, 66 2/3, 60, 50, 40, 30, and 25 Hz. They did not appear in the chronological order listed here, and their selection was influenced, to a great degree, by the types of applications made of electrical power during the early period of electrical technology     

0.1Hz超低频耐压试验装置在发电机耐压试验中的应用

介绍了0.1Hz超低频耐压试验装置的构成、原理,并在某发电厂机组大修时采用该装置进行发电机超低频耐压试验,在1min内向4号发电机的定子绕组施加50.9 kV测试电压,以此来判断发电机定子绕组局部和槽部的绝缘情况。通过试验证明,采用0.1Hz超低频耐压试验装置与传统工频耐压试验装置的试验结果一致,而超低频耐压试验装置的体积和质量明显减小,可有效降低装置的运输成本。     

Effect of humidity on the breakdown characteristics of air in uniform field for the very low frequency (VLF) band

The paper reports about the role of humidity and frequency on the electrical breakdown of air in uniform field gaps. Experiments were conducted on Rogowski profile electrodes with gap lengths ranging from 5 to 53 mm at power frequency (60 Hz) and frequencies in the range of 18-50 kHz, corresponding to the VLF/LF bands used for long-range communication. The results show that breakdown voltage at VLF decreases with humidity, opposite to that observed at 60 Hz. Breakdown mechanisms for explaining this important phenomenon are proposed. A correction factor to calculate breakdown voltage as a function of humidity for VLF is presented.     

我国供用电频率50Hz的起源

在电力工业的发展初期,世界上存在许多种供电频率;旧中国的汽轮发电机组全部来自外国,因此有多种供电频率。1928年,中国民族资本企业上海亚浦耳公司建议国民政府把50Hz作为中国供用电的标准频率。1930年9月,国民政府建设委员会鉴于当时中国发电厂中半数以上的供电频率是50Hz,把世界多数国家采用的50Hz作为中国的供用电标准频率,制定了"电气事业电压周率标准规则",这是中国第一个供用电电压频率标准。中华人民共和国成立后至今,中央政府电业主管机关也都将供用电标准频率规定为50Hz。从目前技术条件出发,如果能够重新选取一次电力系统供用电标准频率,频率最优值可能是几百赫兹。     

Determination of phase angle and amplitude error of voltage and current transformers up to some 100 Hz for loss measurements on power transformers

Contents  For the load loss measurement of power transformers, current and voltage transformers with usually extremely low errors of phase angle and amplitude are used. However, even small errors of the measuring transformers may result in an error in the measured load loss. Therefore, national and international standards allow the correction of the measured value by the amount caused by phase angle and amplitude error of the measuring equipment [2–4]. The determination of the errors of phase angle and amplitude of measuring transformers is carried out on the basis of calibrated standard measuring transformers which are traceable to national standard equipment at rated frequency, e.g. at 50 and 60 Hz. For some applications – e.g. the load loss measurement of HVDC power transformers according to the draft of IEC standard 61378-2 [1] – a load loss measurement at frequencies other than rated frequency is required. For that, the errors of phase angle and amplitude of the measuring transformers must be known. This paper describes a method how to determine the phase angle and amplitude errors of the measuring transformers at arbitrary frequencies on the basis of the calibrated error values at rated frequency. Received: 9 August 2000