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The energy balance equations and exergy balance equations of beat exchanger and power equipment in the combined power cycle were established. Taking condensation temperature of Rankine cycle, inlet and outlet pressure of turbine of Rankine cycle, inlet and outlet pressures of turbine of LNG cycle as key parameters, the influences of these parameters on the thermal efficiency and exergy efficiency of the combined power cycle were analyzed.

建立了混合动力循环中换热和动力设备的能量平衡方程和可用能平衡方程，并以朗肯循环冷凝温度、朗肯循环透平进出口压力、液化天然气循环透平进出口压力为关键参数，分析了上述关键参数对混合动力循环热效率和可用能效率的影响。

Now,the use of wind power is becoming a hot-point during the reacher of renewable power.And many kind of technologies applied to wind power generation are in the ascendant,among which the technology of variable pitch is getting increasing recognition for its characteristic of high-effiiciency and practicability.

目前各种风力发电技术得到迅速发展，变桨风力发电技术和定桨距发电机组相比，因其高效性和实用性越来越受到重视。

College of Electrical Engineering, Zhengzhou University摘要: In order to understand and calculate the reactive power of the nonsinusoidal electric circuit accurately and analyses the the influence of the reactive power in the nonsinusoidal electric circuit on reactive energy measurement .the calculation formula of the reactive power is concluded by means of the Fourier analysis method.

为了能够准确地理解和计算非正弦电路的无功功率，分析非正弦无功对无功电能计量的影响，本文采用傅立叶分析方法，导出非正弦电路的无功功率的计算公式，分析了公式中每一项的物理意义。

The definition of instantaneous reactive power in sinusoidal circuit is still a pending problem and should be studied further. The authors consider that the theory of instantaneous power should be studied on the basis of the original definitions of instantaneous active and reactive power.

针对研究近一个世纪还没有解决的瞬时无功功率界定与定义的问题，该文认为应从原始瞬时有功功率、瞬时无功功率界定来研究瞬时功率理论。

In order to ensure that self-compensating devices for reactive power work stably and reliably in low-voltage electric power system, this paper introduces a new method and steps of selecting compensating devices by comparing their types, based on the theory of reactive power in non-sinusoidal alternating circuit.

产生谐波的根本原因是电力系统中器件、设备的非线性，即使供给这些器件、设备的电源是理想的正弦波形电压，电网供给它们的电流也是非正弦波形，即产生了谐波电流，当谐波电流流过线路后，产生谐波压降，使电网电压失真。

It calculates the active power and reactive power of the net side of the rectification system on-line, which based on the three-phase circuit instantaneous reactive power theory. To provide fast and accurate real-time measurements of active and reactive for new type static var compensators, this paper designs a optimization digital low-pass filter with the approach by combining the Butterworth filters with mean filter.

基于改进的瞬时无功功率理论，在线计算整流系统网侧有功和无功功率，将Butterworth滤波器和均值滤波器相结合，优化设计高性能的数字低通滤波器，为新型SVC提供快速而准确的有功与无功在线测量值。

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。

When a power failure has occurred, the recording head is demagnetized with power in case of a power failure.

当电源故障已经发生时，用在电源故障情况下的电力去磁记录磁头。

Solution: For regular power supply instability, we can purchase UPS or 130-260V power supply for wide computer switching power supply to ensure stability.

解决方法：对于经常性供电不稳的地区，我们可以购置UPS电源或130－260V的宽幅开关电源来保证计算机稳定工作。

With the development of electric power industry and the increase of large-scale substation, the requirement of protection and control of power system is getting higher, and the computer relay protection of power system is also developed with the techniques of intelligent computer, networking and integration.

随着电力工业的发展和大面积多变电所用户的急剧增加，对电力系统的保护及监控提出了更高的要求，电力系统微机继电保护向智能化、网络化和集成化方向发展。

Nowadays, most of research are to build a transmutative Petri Nets through adding controlling place sets, controlling arc sets and controlling policy to the basic Petri Nets, while the Controlled Petri Nets could be used to argue many controlling theory problems conveniently and to induce many logically and physically supervisory and solve the Event Feedback Controlling Problems and State Feedback Controlling Problem in DEDS supervisory theory.

目前大多数的研究表现为在变形后的受控Petri网基础上，利用各种方法求得各种逻辑型、结构型控制器，解决DEDS监控理论中的事件反馈控制问题与状态反馈控制问题。

On one hand, there are discussions with the works council and union about extension of short time working up to the end of September.

一方面，有讨论，工程理事会和联盟关于延长工作时间短至9月底。