电网频率

The research result provides an effective approach for the accurate fundamental wave frequency measurement of the power network.

为精确地测量电网基波频率提供了有效的方法。

On the basis of analysis and comparison of conventional and some modern dielectric loss measurement methods in this paper, considering the difficulty consist in the dielectric loss measurement, such as the problem of the locale measurement of dielectric loss the suffering the interference of the electric field in the electrified wire net, the influence of harmonics and the leakiness of frequency spectrum due to the change of the frequency in power supply etc. a new measurement method which the frequency conversion anti-jamming technology combines the fundamental waves phase detachment method is presented.

论文在分析了传统介质损耗测量方法和现代介质损耗测量方法的基础上，针对介质损耗检测中存在的技术问题，如现场测量时工频电网强电场干扰问题、高次谐波影响问题、供电电源频率改变所引起的频谱泄漏和栅栏效应等问题，提出了采用变频抗干扰技术和基波相位分离法相结合的新型测量方法。

One of the main characteristics of circuit breaker is that the breaker can open normal current and short circuit current.

本文综合前人所做工作，详细描述了智能操作断路器控制器的工作原理及其主要控制基础，而电网的信号处理、断路器机构调整的方式、频率跟踪等是控制器的重要组成部分。

The difficulties during developing this technique is that dielectric loss tangent measured is very small, and many factors influence the high-precision measuring, such as the excursion of the primary wave on power line, the existence of the harmonious wave, and the electromagnetic interference in the field and so on.

该检测技术的难点在于待测介质损耗角很小，电网基波频率不稳、高次谐波的存在以及现场电磁干扰等因素都会影响测量准确度的提高。

Those are measured and calculated by computer such as voltage, current, frequency, active power, reactive power and power factor. The errorless of three-phase voltage and current is less than 0.5 percent.

用微机实现对电网电压、电流、频率、有功功率、无功功率、功率因数的测量和计算；计算高压配电线路得出的三相电压、三相电流有效值误差小于0.5％。

But the filtering performance is sensitive to the detuning caused by the change of system frequency and filter' s parameters.

但是，调谐滤波器的滤波效果对电网和滤波器参数的变化比较敏感，随着运行频率的变化和设备老化，滤波器的滤波性能变差。

In MicroGrid if traditional synchronous generators were used as the main power support, the frequency of MicroGrid would fluctuate greatly during MicroGrid operated from isolated mode to grid-connected mode, and some distributed generations maybe were disconnected from the grid by low frequency relay.

如果选择微型燃气轮机作为微网的主要功率支撑手段，在微网从并网向孤网过渡过程中，系统频率波动较大，且部分分布式电源有可能在低频保护动作下与电网隔离，不利于微网的稳定运行；增加储能设备后，储能设备对于微网的稳定运行可发挥重要的作用。

Geo-magnetically induced currents are triggered by geomagnetic storms, the frequency of which ranges from 0.001 Hz to 0.100 Hz. GIC will cause DC bias saturation of transformers, unnecessary relay tripping and blackouts.

中文摘要：磁暴在输电线路引发的地磁感应电流频率为0.001～0.100 Hz，这种准直流的GIC将造成变压器直流偏磁饱和，引发电网保护误动作和停电事故。

The authors analyze the operation characteristic of distance protection of transmission line connecting wind farm with power grid under the variation of parameters such as the amplitude ratio of electromotive force at both sides, the phase difference of electromotive force at both sides, equivalent impedance of sources, system frequency and so on; based on the real-time current and electromotive force at wind farm side as well as the information of wind power generators participating power generation, a method to adaptively set the operation boundary of distance protection by use of the information at wind farm side only is proposed.

文章分析了风电场和电网联络线的距离保护随电源电势幅值比、电势相位差、电源等效阻抗、系统频率等参数变化时的动作特性，并基于风电场侧的实时电流和电势与参与发电的发电机信息，提出了仅利用风电场侧信息量自适应整定保护动作边界的方法。

This device can measure frequency,electric voltage and variety rate quickly, distinguish shortcircuit breakdown, judging the size of power deficiency vacancyinside a system.

一旦电力系统出现不稳定它能快速切除接近于功率缺额的负荷，抑制系统电压频率的快速降低，保证电网安全并保障一些重要用户的供电质量。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。