| 1. | Among them , the action of the reactive current testing circuit is testing the reactive current component in the compensated object current 其中,无功电流检测电路的作用是检测出补偿对象电流中的无功电流分量。 |
| 2. | When zero sequence or high secondary harmonic current component appear in the circuit , the total current in the shield is zero , no electromagnetic interference with outside 当线路出现零序或高次谐波电流分量时,屏蔽层内电流总和为零,不对外界产生电磁干扰。 |
| 3. | In this paper , the on - line monitoring technique of leakage current , especially of the resistive leakage current through the zno surge arresters under operating voltage is discussed . the existing different monitoring methods are investigated at fist 本文对氧化锌避雷器运行电压下的泄漏电流、尤其是阻性电流分量的监测技术进行了研究。在综合现有监测方法的基础上,基于阻性电流基波法提出了一种改进的基波法。 |
| 4. | This approach is called fas . this approach uses characteristics of trigonometric function , respectively computes the amplitude of fundamental component and inactive power current separates them by low pass filter and acquires and inactive power current 该方法利用三角函数的特性,对畸变电流中的基波成分和无功电流分量的振幅分别进行计算,然后经过低通滤波器把它们分离出来,最后得到基波有功和无功电流分量。 |
| 5. | The paper lucubrated the control theory of induction motor ' s vector transform and the method of calculating speed by induction motor ' s torque current weight , based on which , the paper designed a close - loop speed - sensorless vector control vwf system and realized the system in matlab / simulink 本文深入研究了感应电动机矢量变换的控制理论和利用电动机转矩电流分量进行速度推算的方法。在此基础上设计了一个闭环的无速度传感器矢量控制变频调速系统。 |
| 6. | Motion control is a comprehensive subject . modern ac drive is a important embranchment in the field of motion control . however , it is difficult to rea1ize high - performance ac drive systems because induction motors are a kind of strongly - coupled nonlinear system with many variables and the torque is not easy to control . with vector control technology decoupling and torque control of ac motor are solved . the basic idea of vector control is that three - phase system is equiva1ent to two - phase system by coordinate transformation and it realizes the decoupling between field current and torque current of the stator in order to control the flux and current respectively , thus induction motor can be considered dc motor and high performance is achieved easily . with the progress of electric and electronic technology and the development of computer , high - integrated special modules and high - precision digital signal processor ( dsp ) are applied to ac drive so that vector control has been developed rapidly 但是高性能的交流调速系统实现很困难,这是因为交流电机是多变量、强耦合的非线性系统,不易实现高性能转矩控制。矢量控制技术则解决了交流电机解耦与转矩控制问题,其基本思路? ?应用坐标变换将三相等效为二相,实现定子励磁电流分量与转矩电流分量之间的解耦,达到对交流电机磁链与电流分别控制的目的,交流电机等效为直流电机实现高性能调速。随着电力电子技术的进步,计算机技术飞跃发展,高度集成的专用模块和高精度的数字信号处理器应用于交流传动系统中,促进矢量控制迅猛发展,日趋成熟。 |
| 7. | Then , this thesis presents an algorithn of 2 - terminal quantity fault location based on synchronous gps sampling . this algorithm conducts fault location with only the 3 - phase fundemental wave voltage and current phasors of the 2 terminals of transmission lines and apples to lines of both symmetrical and asymmetrical parameters , irrelerant to the impedence , fault types and transitional resistance of the 2 terminals of lines 然后,本文提出了一种基于gps同步采样的双端量故障测距算法。该算法仅利用输电线路两端的三相基波电压、电流分量来进行故障定位,不受线路两端系统阻抗、故障类型、过渡电阻等因素的影响,对参数对称线路和非对称线路均适用。 |
| 8. | It is found that the electron beam may approach ideal bunching . high power microwave pulses with tunable frequency can be generated by post - accelerating the electron beam and carefully designing the extraction cavity . in terms of the pic simulation , the output power of 1 . 25gw at 2 . 2ghz and 480mw at 4 . 4ghz in axial acceletron have been obtained 用增加中间腔的办法,大大提高了前两阶谐波电流分量,数值计算结果表明,其中一阶谐波电流调制系数达到了140 ,二阶谐波电流调制系数达到了68 ,通过改变提取腔的设计,可选择不同频率的输出,其一次谐波频率为2 . 2ghz ,输出功率为1 . 25gw ,效率为9 . 33 ,二次谐波频率为4 . 4ghz时,输出功率为0 . 48gw ,效率为3 . 6 。 |
| 9. | Space vector control according as ac induction motor two - axis theory speed separates the stator current into two components . one is the torque component ; the other is the flux component . a structure similar a dc machine structure where torque and field can be controlled independently is given 矢量变换控制是以交流电动机的双轴理论为依据,在同步旋转坐标系中把定子电流矢量分解为两个分量:一个分量与转子磁链矢量重合,称为励磁电流分量;另一个分量与转子磁链矢量垂直,称为转矩电流分量。 |