工频

Moreover, the advantages and disadvantages of various travelling wave based protective theories are analyzed.

目前在输电线路上广泛采用的是反应工频电气量的继电保护装置。

Aiming at the difficulty in the travelling wave based protection, the corresponding measures are proposed.

这些保护装置的构成原理是建立在反应工频电压、电流或由其组合的功率方向、阻抗等基础上的。

The paper focuses on the extracting of travelling wave information, the development of associated technique field and the application of analysis tool based on wavelet transform.

为了保证保护装置能在故障时正确动作，在传统的反应工频电气量的保护装置中，通常采用滤波等方法来消除暂态过程对保护的影响。

Common fault components and differential fault components are introduced into the algorithm to uncouple mutual electromagnetic coupling effect between two parallel circuits.

基于反序故障网络和故障边界条件，本文提出了一种利用双回线单端工频电流量的同杆双回线准确测距新算法。

The purpose: AC filter capacitor complete unit is connected into the power system of power frequency to filter harmful harmonic current out in power system and improve the quality of power, increase power factor.

产品用途：交流滤波电容器成套装置接于工频电力系统中，有以滤除电力系统中有害的谐波电流，改善电能质量提高功率因数。

Its software uses system self-detecting algorithm to assure measurement channel .It uses softening hardware technique software synchronic data sampling to trace the frequency of exterior signal, in other words , it gives sampling control signals 128 times of power net's frequency .It uses Direct Digital Frequency Synthetics algorithm to transform radical sine waveform parameter table into needed current. It uses FFT algorithm to get radical waveform altitude of current ,voltage and resistor .

整个系统在软件设计上采用系统自检验算法保证测量通道可用，采用硬件软化技术--软件锁相环技术，达到对外部信号频率的跟踪，给出频率为电网工频128倍的采样控制信号：直接数字频率合成技术将基波参数表转换成需要的电流信号，采用FFT变换及基波幅度的计算方法得到被测电流、电压基波幅度和电阻大小。

The copper alloys with high strength and high conductivity was melted by a coreless frequency induction furnace and alloying elements were directly added into alloy liquid. It not only reduced the cost, but also improved the production efficiency. So the method was suitable for an industry production.

本文采用将合金元素直接加入有芯工频感应电炉的方法熔炼高强高导铜合金，既降低了成本又提高了生产效率，满足了工业化大生产的要求。

Based on the accidents in test and operation of line-frequency coreless induction furnace , the safety proceedings in furnace lining sintering, furnace drying and the melting operation and the emergency treatment methods of service interruption, leakage of steel and accident of cooling water have been pointed ou

针对无芯工频感应电炉试炉及运行过程中易发生的事故，提出了炉衬烧结和烘炉、熔炼操作过程中应注意的安全事项，以及停电、漏炉、冷却水事故的紧急处理方

Based on the theoretical analysis of the industrial frequency induction heating technique, a detacher used for the bearing inner race was developed.

在理论分析的基础上，研制了基于工频感应加热技术的轴承内环感应拆卸器。

The furnace body is made ф2200×1500 the outer covering main body by the 12mm steel plate, lower part the furnace body 45° the installment has the sensor, the sensor orientation silicon steel plate is made the weight 2 ton induction iron cores by Wuhan Steel Corporation Silicon steel plate Factory production top gear's W-151 the cold rolling 0.35m/m, primary is made the water cooling coil by 10×10×2 the copper pipe, and installs the stainless steel water cooling restricting, the power frequency has the core smelting furnace's metal melt fluid namely for the sensor sencondary coil, the entire electric stove is a transformer actually, the necessary 6 grades from the pair regulating transformer, shift gears by the electricity cabinet control, the voltage may from low to high, divide 6 promotions to arrive at 380V, each grade of voltages are different, the output is also different, the furnace temperature along with the files position is also different, but the height is different, adapts smelts colored or the black and so on melting point different metals, and may make the new furnace lining to smelt diamantine drying furnace fireproof.

炉体由12mm钢板制成Ф2200×1500外壳主体，炉体下部45°安装有感应器，感应器由武钢硅钢片厂生产的最高档的W-151冷轧0.35m/m取向硅钢片制成重2吨感应铁心，初级由10×10×2铜管制成水冷线圈，并安装不锈钢水冷保护套，工频有芯熔炼炉的金属熔液即为感应器的次级线圈，整个电炉实际就是一个变压器，配套一台6档的自耦调压变压器，由电柜控制换档，电压可由低到高，分6级升到380V，每档电压不同，输出功率也不同，炉温也随档位不同而高低不同，以适应熔炼有色或黑色等熔点不同的金属，并可作新炉衬耐火冶金砂烘炉之用。

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。