瞬时电流

It analyzes the principles of technology which consists of ip-iq harmonic current detecting method based on the instantaneous reactive power theory and the hysteretic control of compensating current method.

分析了基于瞬时无功功率理论的ip-iq谐波电流检测技术和电流滞环比较控制的补偿电流技术。

Considering the variation of the equivalent instantaneous inductance, an new algorithm based on the normalized equivalent instantaneous inductance for the discrimination between inrush and fault current is creatively proposed.

另外，从分析等效瞬时电感的变化入手，创造性地提出了一种基于归一化等效瞬时电感分布特性的识别励磁涌流和故障电流的方法。

The commonly used real time detecting theory of instaneous reactive and harmonic current based on vector transform has the shortcomings of complexity of vector transform and illegibility of physics meanings.

针对建立在瞬时无功功率理论的基础上的瞬时无功和谐波电流检测算法存在的矢量变换复杂，物理意义不明确的缺陷。

The paper introduces an improved harmonic and reactive current detecting method based on there-phase reactive current using instantaneous reactive power theory. By using matlab, simulation model is built, and the results show that this model can exactly detect harmonic and reactive current in time and it is feasible in DSP system.

本文在三相瞬时无功功率理论的基础提出了一种改进的单相无功电流检测算法，并建立了仿真模型，仿真结果表明：该算法可以及时、准确地检测出三相电路中的谐波电流和无功电流，同时也验证了此算法在DSP系统中的可行性。

Based on the instantaneous output voltage and filter inductor current double closed loop feedback control and through sharing the same voltage regulator, the current sharing is achieved.

基于主从控制的逆变器并联系统由3个采用输出电压瞬时值和滤波电感电流瞬时值双闭环反馈控制的逆变器模块构成，通过共用电压调节器实现负载均分。

The results show that the equiaxed zone ratio of the casting billet is greatly increased,with its soidification structure is obviously improved,and the momentum values of the electromagnetic forces both parallel to and perpendicular to the direction of the traveling magnetic field pulsate periodically with time.

采用三相通入不同电流的非平衡线性电磁搅拌技术进行了铸坯的静态浇铸实验，并对电磁搅拌过程中钢液内的电磁力各分量的瞬时值进行了理论分析·结果表明，当采用将电磁搅拌器的三相通入不同电流的非平衡线性电磁搅拌时，在钢液内所产生的电磁力是脉动的，其大小呈周期性变化，尤其是垂直于磁场运动方向上的电磁力，其脉动的幅度很大·由此认为，当采用将搅拌器的三相通入不同电流的非平衡线性电磁搅拌时，所产生的垂直于磁场运动方向上的脉动电磁力是提高等轴晶比率，改善铸坯凝固组织的一个重要原

The result indicates that the harmonic detection means based on instantaneous reactive power theory can detect harmonic and reactive component in three-phase current precisely and real-time, to supply reliable harmonic and reactive current for harmonic restraint and reactive power compensation.

仿真结果表明：基于瞬时无功功率理论谐波检测方法可以准确、实时地检测出三相电流中的谐波电流及无功电流，可为抑制谐波和无功补偿提供可靠的谐波及无功电流分量。

The instantaneous power theory was employed to analyze the instantaneous power of the control winding and the control scheme for the DWIG system with diode bridge load was obtained. The component of the currents on the control-winding flux determines the instantaneous reactive power, and the component on the perpendicular direction of the flux decides the reactive power. The former one influences the DC voltage of the diode bridge on power winding and the latter one influences the DC voltage of the static excitation controller of control windings.

基于瞬时功率理论，推导出按控制绕组磁场定向时控制绕组的瞬时功率，在此基础上分析了带整流桥负载的定子双绕组感应电机发电系统在宽转速运行时的电压调节机理，即：控制绕组电流在控制绕组磁场及其法线上的分量，分别决定着发电系统功率绕组整流桥直流侧电压和控制绕组静止励磁控制器(static excitation controller，SEC)直流侧电压，据此提出宽转速运行时DWIG发电系统电压控制策略。

It is introduced that harmonic current in the electric network and harmonic current detecting method based on instantaneous reactive power theory in the paper,and then it presents the current detecting method in the anisomerous mains voltage,aberrance circuit based on instantaneous reactive power theory .

通过对电网谐波和瞬时无功功率理论在谐波检测中应用的分析研究，作者给出了基于瞬时无功功率理论的检测方法在电网电压不对称、存在畸变时的电流检测方法。

3The dissertation makes a deep analysis on the calculation of the equivalent instantaneous inductance of wye-connected transformer. It concludes that the looping current in the winding of delta side of transformer, which is hard to obtain from line current, severely influences the calculation result of equivalent instantaneous inductance. In that case, a new scheme of transformer differential protection is proposed.

深入分析了变压器 Y/Δ接线方式下等效瞬时电感的计算问题，针对Δ侧绕组环流对等效瞬时电感计算结果影响大，而又无法通过线电流计算得到的特点，提出一种变压器差动保护 TA 配置新方案。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。