查询词典 transient current

A computer-aided local transient flow property measuring system was developed using a high speed CCD camera coupled with optical fibers in order to study the Gas-liquid-solid three-phase jet loop reactors. SnO2 crystal films were orientally deposited on the alkoxysilane molecule-coated hydroxyl glass substrates so as to prepare surface-marked particles as the tracers. An image analysis system was established to identify different phases. Stroboscopic photography was utilized to extend the measure range. The developed measuring and analysis system was capable of determining accurately the local transient flow property in a G-L-S jet loop reactor. Based on the above system, local transient flow properties of gas, liquid, and solid phase were measured and studied the influences of fluid property, operation and configuration parameters on the reactor.

中文摘要：以气液固三相喷射环流反应器为研究对象，将高速CCD和光纤束耦合制成局部瞬态流动特性微机数据采集及图象处理系统，利用MPS硅烷分子在带有羟基的玻璃基底上的自组装引导SnO2晶态膜层在功能化表面上进行沉积，以获得表面标记的示踪粒子，解决图象处理技术与相的识别的问题，利用频闪技术拓展了测量上限，得到可以准确测定气液固三相喷射环流反应器中局部瞬态流动特性的测试系统；采用上述测试技术进行喷射环流反应器中局部气相、液相与固相瞬态流动特性的实验研究，并考察物性参数、操作参数与结构参数的影响规律。

By using this method, the angular frequency, amplitude, initial phase angle, decay constant of each component in transient voltage and/or current waveforms can be precisely extracted. Also, all other kinds of transient procedure can be analyzed by this method. Thirdly, a new definition of generalized instantaneous reactive power and generalized instantaneous reactive current in dq0 coordinates under any nonsinusoidal and unbalanced three-phase circuit is proposed for the first time. The detection and compensation method for different instantaneous reactive currents are also concerned.

本文首先提出了用于快速高精度频谱分析的一种改进快速傅立叶变换方法，该法具有速度快、精度高、抗混迭、不受采样定理约束、可以分析出谐次大于N／2的频谱系数等特点，可方便地应用于电力系统谐波分析及其它各类频谱分析；然后提出了基于非线性最小二乘优化法的电力系统暂态波形分析方法，可准确求出电力系统暂态电压、电流波形中各个分量的角频率、幅值、初相角及衰减常数，并可广泛应用于各类暂态过程波形分析。

Boundary polynomial point interpolation mesh-free method and boundary radial point interpolation mesh-free method were presented, based on polynomial basis and radial basis respectively for transient eddy current analysis, and their interpolation shape functions satisfy the Kronecker delta function and the essential boundary conditions can be directly imposed on the boundary nodes. An example on analyzing transient eddy current of a square metal column was set to prove the validity of the proposed methods, and a comparison on accuracy between BPPIM and BRPIM was analyzed as well.

运用多项式点插值法和径向基点插值法构造形函数，推导了适合于工程电磁场瞬态涡流问题的多项式基点插值边界无单元方法和径向基点播值边界无单元方法，这两种方法的空间插值形函数满足Kronecker delta条件，从而强加边界条件可以直接施加在边界点上，以金属长方柱的瞬态涡流分析作为数值算例，证实了两种方法的正确性和有效性，并对两种基类的点插值法进行了精度分析和比较。

So, When the power system is in transient, the sliding mode control rule is chose directly to make transient component decrease quickly, and when the power system is in stability, the direct current control method based on voltage space vector method is imported to make the error current reduce to zero by inches and avoid surge.

为此，当系统处于暂态时，论文直接选择滑模控制率使暂态分量迅速减小，当系统处于稳态时，引入基于电压空间矢量的直接电流控制方法，使误差电流趋于0缓慢变化，在有效补偿系统无功的同时，提高了系统的动态特性，并大大降低了系统振荡的可能性。

On the basis of the analysis of the transient negative current, a compensated voltage can be generated with multiplying the rms value of the negative sequence transient current of the feeder by a settable compensated reactance, then combined with the magnitude of the zero-sequence voltage to consist of the compounded compensated voltage, which can be utilized to revise the characteristics of the inverse time-delay.

其基本保护采用零序过电压保护，动作时间采用反时限特性；在分析接地故障负序暂态电流分布特点的基础上，利用线路负序电流暂态有效值与一个可整定的补偿电抗相乘，形成补偿电压，并与零序电压幅值合成复合补偿电压，利用该电压对基本的反时限动作特性曲线进行修正，使零序过电压保护具有选择性。

The inverse time delay characteristic is adopted by the basic zero-sequence over-voltage protection. On the basis of the analysis of the transient negative current, a compensated voltage can be generated with multiplying the rms value of the negative sequence transient current of the feeder by a settable compensated reactance, then combined with the magnitude of the zero-sequence voltage to consist of the compounded compensated voltage, which can be utilized to revise the characteristics of the inverse time-delay.

其基本保护采用零序过电压保护，动作时间采用反时限特性；在分析接地故障负序暂态电流分布特点的基础上，利用线路负序电流暂态有效值与一个可整定的补偿电抗相乘，形成补偿电压，并与零序电压幅值合成复合补偿电压，利用该电压对基本的反时限动作特性曲线进行修正，使零序过电压保护具有选择性。

Moreover, second-winding current waveform of a current transformer is calculated under the transient current of the typical short-circuit fault by numerical method. The analysis shows that the relevant protection equipment may refuse to trip when the fault current is extra high. It will result in the maloperation of protective relays for loss of their selectivity, and cause other protective relays to operate beyond range, and extend the scope of shutdown of power supply.

在这些回路出口处发生相间直接短路等严重故障时，流过相应TA一次侧的故障电流可能达到TA额定工作电流的100倍以上，大大超过了保护用TA的10%误差容许倍数，将使TA严重饱和，从而影响相关的保护设备的动作性能，因此有必要对在这种特大电流作用下的TA的传变特性做一些探讨，以分析其对继电保护装置动作特性的影响及应采取的措施。

In summary, the drive current by Alfvén waves can be enhanced by plasma rotation The negative magnetic shear is favorable for the efficiency of the current drive by Alfvén waves Moreover, in the reversed shear configuration the current drive due to Alfvén waves in an rotation plasma can obviously change the plasma current profile The Alfvén wave current drive may be useful in controlling the current profile in order to suppress magnetohydrodynamic instabilities.

另外，我们还发现负剪切区域愈大，同时安全因子极小值q〓愈小，对阿尔芬波电流驱动愈好。总之，等离子体极向旋转能够增强阿尔芬波电流驱动，负磁剪切对阿尔芬波电流驱动是有利的。另外，反磁剪切位形下旋转等离子体的阿尔芬波电流驱动可以明显改善等离子体电流剖面。

The topic research, standard device for resistive current tester for zinc oxide surge arrester, can be used for calibration for resistive current tester for zinc oxide surge arrester. The equip functions involve: total current, resistive component of current, capacitance component of current, active power, reference voltage, phase angle, harmonic component of current.

课题研制的氧化锌避雷器阻性电流测试仪标准装置可用于开展氧化锌避雷器阻性电流测试仪的校准工作，项目涉及：全电流、阻性电流、容性电流、有功功率、参比电压、相位角、各次谐波电流分量。

Week 14 Magnetic effect of current, Ampere molecule current hypothesis, current intensity and current density vector, condition of steady current, magnetic field of steady current, magnetic induction vector B;Biot-Savar- Laplace law and its application.

第14周电流的磁效应；安培分子电流假说；电流强度和电流密度矢量；稳恒电流的条件；稳恒电流的磁场；磁感应强度矢量B；毕奥-萨伐尔-拉普拉斯定律及应用。

Foods high in this vitamin include oily fish such as salmon, tuna and, and fish liver oils.

维生素D含量高的食物包括诸如大麻哈鱼、金枪鱼和鲭鱼之类的油鱼以及鱼肝油。

We need you to cosign our public letter demanding that press intimidation cease immediately, and that all charges be dropped.

我们需要您cosign我们的公共信，要求记者立即停止恐吓，并要求所有收费下降。