无功的

With the needs of reducing line loss, to study the method of compensating reactive capacity has been an important task in power department.

为了降低因传输无功功率所造成的线损，无功补偿受到电力工业部门越来越多的重视。

Furthermore, it is not worth to transmit reactive power for long distance. Control provided "on the way" in transmission line, connation nodes, distribution station and other points requires installation of capacitors or\and reactors.

此外， 远距离地传输无功功率是没有必要的，无功功率在传输线路，各个节点，配电站和其他需要安装电容或者电抗器的地方被人为地控制着。

By adding an equivalent harmonic impedance in the branch circuit of power grid, this HAPF could force all the harmonic currents flow into passive power filters, which resulting in eliminating harmonic contamination more effective. And using the capacitive feature of PPF in the fundamental frequency, this HAPF could compensate fixed-capacity reactive power without increasing APF's burden. Moreover, in order to decrease APF's cost, the fundamental voltage will largely be endured by capacitor in view of the series resonance circuit tuned at the fundamental frequency, so the APF just bears little harmonic voltages.

其基本工作原理是：有源部分等效于在电网支路中串联了一个谐波阻抗，该谐波阻抗对基波电流不起作用，而对谐波电流产生很大阻碍作用，迫使谐波电流流入无源滤波器，从而达到滤除谐波的目的；同时新型注入式混合有源滤波器还充分利用了无源滤波器的无功补偿功能，在不增加有源部分容量的前提下，可以提供一定容量的无功功率；由于有源部分承受的电网基波电压不大，也没有基波电流流入，因此逆变器容量小，初期投资较小。

Instantaneous reactive power theory applied on harmonic and reactive current real-time detection is presented in this paper.

介绍了瞬时无功功率理论在谐波和无功电流实时检测方面的应用。

Based on the instantaneous reactive power theory, the method of detecting reactive current of agricultural power network is studied.

为了抑制谐波和补偿无功，国内外研制了许多新型的无功补偿装置和有源电力滤波系统。

For accurate measurement of reactive power in non-sinusoidal circuit, this article introduces a method integrating quasi-synchronous sampling theory with digital-phase-shift network..

在给定定义下，为了准确测量全无功电能，本文介绍了一种结合准同步算法和离散Hilbert的无功测量方法。

The technique made full use of the characteristic of PR controller which can realize zero steady-state error in AC input signal in stationary frame. In the method, the active and reactive current component in the vector control strategy were transformed in the stationary frame to achieve the objective of keeping the DC-link voltage constant, adjusting the power factor and decoupling the active and reactive power. Compared with conventional double close-loop proportional integral controller, the PR technique is better in harmonic compensation without the complex rotating frame transformation and the couple or feedback voltage which is easily influenced by temperature and circuit parameters. The control algorithm is easy to be realized while the robustness and power quality is improved.

该方法充分利用了PR控制器能够在静止坐标系下对交流输入信号无静差控制的优势，将矢量控制策略下的有功电流和无功电流分量转换到静止坐标系下进行调节，实现网侧变换器维持直流电压稳定和调节功率因数的控制任务和双馈电机有功、无功功率的解耦控制，与传统的双闭环PI控制相比，该策略无需繁琐的坐标旋转变换，不存在受温度及电路参数影响的耦合项和前馈补偿项，且易于实现对系统低次谐波电流的补偿，减小了控制算法实现难度，提高了控制系统的鲁棒性和电网电能质量。

To improve the convergence and accuracy in reactive power optimization, this paper proposed a global sequential quadratic programming algorithm to calculate optimum power flow.

为提高无功优化计算的收敛性和精确性，采用全局序列二次规划算法来计算无功优化潮流。

By using the classic calculation method for reactive power compensation, the optimum compensation capacity and compensation position for the network with single power can be easily defined.

通过经典无功优化算法，可以比较简便的计算出在单电源配电网中最佳无功补偿容量和最佳补偿位置。

This series of instruments for low-voltage, medium voltage, high-voltage switchgear and distribution systems, central station monitoring system, generator set systems, building automation systems, energy management system, such as factories, able to measure three-phase three-wire, three-phase four-wire system current, voltage, active power, reactive power, apparent power, active power, reactive power, power factor, frequency, voltage triangular openings, the largest open-shaped voltage power parameters, at the same time with a remote, remote control function.

该系列 仪表适用于低压、中压、高压开关和配电系统、中心电站监测系统、发电机组系统、楼宇自控系统、工厂能量管理系统等，能够测三相三线，三相四线系统的电流、电压、有功功率、无功功率、视在功率、有功电能、无功电能、功率因数、频率、开口三角形电压、最大开口形电压等电力参数，同时带有遥信、遥控功能。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。