无系统的

In order to improve the power quality of distribution network system, one of the most effective methods is reactive power compensation. In this paper, the Distribution Static Synchronous Compensator for reactive power compensation was studied, and then the digital controller based on One-cycle control was designed. The waveforms of experimental device based on DSTATCOM of one-cycle control were given in this paper. It can be seen from the results that the fluctuation of DC capacitor voltage is lower, the dynamic response speed of DSTATCOM providing or absorbing reactive power is fast, and the accuracy of steady-state compensation can achieve the requirements of reactive power compensation in engineering basically

为了提高配电网系统的电能质量，对无功功率进行精确补偿是非常有效的方法之一；本文研究了配电网静止同步补偿器用于无功补偿，并设计了单周控制的数字控制器；文中给出了基于单周控制的DSTATCOM无功补偿试验装置工作过程中的波形曲线，从试验结果可见，本文设计的单周控制DSTATCOM无功补偿装置的直流侧电容电压在工作过程中波动较小，装置发出或者吸收无功功率的动态响应速度较快，稳态补偿精度基本能够达到工程中无功补偿的要求。

A convex combination condition and a switching strategy are derived.

针对离散单时滞切换系统，提出了一个使系统渐近稳定的充分性条件，给出了该系统的无记忆状态反馈镇定和无记忆输出反馈镇定，并将结果推广到不确定离散时滞切换系统的鲁棒镇定。

The discrete reactive power optimization in power system is studied in this dissertation From the existing mathematical and ...

本文对电力系统及配电系统的离散无功优化问题进行了详细系统的研究，提出了离散无功优化的各种模型与算法。

From the perspective of minimum transmission losses, an instantaneous reactive power theory for systems with any number of phases and with or without neutral line is developed. Under the new definition, each quantity has its own physical meaning, and the zero sequence current can be decomposed into active and reactive components. Furthermore, a generalized compensation method for zero sequence current is developed.

从输电损耗最小的角度出发，提出了任意相无中性线或有中性线系统的瞬时无功功率理论，在新的理论下，每个量都有清晰的物理意义，且能分解出零序电流的有功分量和无功分量，并给出了通用的零序电流补偿方法，揭示了瞬时无功功率理论与传统平均意义下的无功功率理论的联系及本质区别，从而为研究HVDC-VSC及各种FACTS装置的无功功率控制奠定了理论基础。

The joint effect of active and reactive power on the voltage stability of a typical power system was considered by analysing the two parameter bifurcation problem related to nonlinear oscillation phenomena. Numerically, as the active power P1 increases, the Hopf points get closer and eventually coincide at P1=1.455 43 the cyclic fold curve gets closer and closer to the Hopf curve and finally intersects the Hopf curve at a singular point the period-doubling points also get closer and finally coincide at P1≈0.65. The stability behaviour is pre-determined using the normal form approach near the limit point of the Hopf curve. Hence, in the power system attention should be paid to both the consumption of active power and the decrease in the reactive power to prevent nonlinear oscillations. A controller can be designed to absorb some active power and to avoid the nonlinear oscillations that damage the system components.

针对一个典型的单机无穷大电力系统，通过分析系统的双参数分岔的非线性振荡现象，综合考虑有功和无功功率对电压稳定性的影响数值分析表明，随着有功功率的增加，电力系统的Hopf点越来越靠近，最终合为一点在P1=1.455 43处同时圈折cyclic fold 曲线也越来越靠近Hopf曲线，并在Hopf曲线的稳定与不稳定临界点处与Hopf曲线相交倍周期分岔点也随着越来越靠近，最终在P1≈0.65 合为一点应用正规形理论方法，初步确定了Hopf曲线极限点附近的稳定性态因而，电力系统应注意让负荷利用有功功率，减少无功功率的产生以防止非线性振荡另外，可以设计一个稍微吸收网络的有功功率的控制器，以避免因周期振荡而造成电力系统仪器的损坏或电压崩溃

According to the reactive characteristics of the distributed generation and the shortcomings of the compensation system for static var compensator, based on the instantanous reactive theory and symmetrical component method, a real-time method for calculating the value of reactive power of the system is presented.

根据分布式发电的无功特点及现在SVC补偿系统的不足，利用瞬时无功理论和对称分量法，提出一种实时求取电力系统无功功率的方法。

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。

Focusing on some disadvantages in standard BP algorithm, such as low convergence rate, easily falling into local minimum point and weak global search capability, Genetic algorithm is used to optimal the connection weight of BP Algorithm in this paper, and construct a GA-BP algorithm of evolutionary neural network, and the algorithm is applied to the control of BLDCM speed adjusting system.

针对标准BP算法存在全局搜索能力弱和易陷入局部极小点等缺点，本文将遗传算法与BP神经网络相结合，构造了一种新的进化神经网络GA-BP算法，并将该算法应用于无刷直流电机调速系统的控制，仿真结果表明，与传统的PI控制系统相比，该算法得出的电机控制曲线几乎无超调，与基于BP算法的速度控制系统相比较，具有收敛速度快、不易陷入局部极小的优点。

In order to adapt the rural electricity system which has the character load fluctuate frequentand the range of fluctuate is large, this paper apply instantaneous reactive power theory to detectreactive current of the system, this method enhance the speed of detection, at the same time, it canassure the detection precision when the load of rural electricity system is dissymmetric.

为了适应农电系统负荷波动频繁且波动范围大的特点，本文应用瞬时无功功率理论检测系统的无功电流，这种检测方法即提高了检测的速度，同时在农电系统负荷不对称的情况下也能保证检测精度。

Furthermore, we discussed and pointed out the exact distinction of the meanings of reactive current, irregular current, reactive power and irregular power, then we give them proper mathematic definition with uniformed conception respectively, we established new power system, which is helpful for people to understand about nonsinusoidal system and its energy conversion much more deeply and substantialy, especially to gain new ideas on depressing and eliminating harmonic waves, and some new design method for more satisfying correcting power function, and different kinds of compensation and eliminating harmonic wave systems.

本文分析了传统的正弦系统有关定义及其与非正弦系统的异同，指出了前者存在的缺点，结合所给特例，讨论并确定了时域中非正弦系统有功电流和有功功率的严格定义，阐明了畸变功率在非正弦系统能量转换过程中所起的作用，在上述基础上，进而讨论并严格区分子无功电流、畸变电流、无功功率、畸变功率等的含义，并利用变分法给出了与上述含义相一致的各个概念的严格的数学定义；提出了新的功率体系。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。