电能

A power line harmonic analyzer based on industrial PC is introduced.The system structure,the basic circuit design of si gnal pre-processing card,the basic HW and SW composition of data acquisition ca rd,and the system software design are described.

介绍了用PC机组成的电能质量分析仪的整体构成，信号预处理卡的基本电路设计，数据采集板的基本软、硬件结构及整个系统的软件设计。

It has harmonic analysis function and power energy accumulation function. It can analyze voltage, 2-50 times harmonic capacity of current, total harmonic capacity.

具有谐波分析功能，能同时分析电压、电流2～40次谐波含量及总谐波含量；电能累计功能。

We choose the TMS320VC5402, digital signal processor, as the computing unit, filtering the sampled signal, truncating the harmonic whose frequence greater than 2500hz, then we use the window-interpolation FFT algorithm to get the refined frequence, amplitude, phase of harmonic in sampled voltage and current, other parameter such as harmonic ratio, active power, reactive power, power factor, three-phase unbalance can be also computed base one the result of window-interpolation FFT.

选用TMS320VC5402高速数字信号处理器作为运算单元，先对采样信号进行数字滤波，去除50次以上谐波分量，然后应用加窗双峰插值FFT算法计算电压电流的各次谐波频率、幅值和相位，以及谐波含有率、有功功率、无功功率、三相不平衡度等各项电能指标，同时利用锁相环电路硬件跟踪电网频率以减小采样失步度。

It is the premise and reference of improve and harness power quality.

这是治理和改善电能质量的必要前提和依据。

The primary goal is to maintain proper alignment at the head, torso and lower body, so as to minimize resistance and encourage the transfer of energy through muscle elasticity and coordination.

首要的目标是让头、躯干和下背部保持正确的线条，从而降低水的阻力，将肌肉协作和收缩的电能做为能量传递出去。

The effect of piston heating temperature on the piston assembling of 4125 diesel engine has been studied.

试验研究4125柴油机活塞加热温度对装配性的影响，从而降低了装配活塞的加热温度，节约了电能，改善了装配性。

It shoewd that nonlinear load injects hormonic power to system, and creates the negative error to energy metering.

实验结果表明，非线性负荷向电力系统注入谐波功率，并对电能计量装置产生负误差影响。

Hot plate is a thermal energy to electrical energy conversion devices.

发热盘是一将电能转换成热能的装置。

The government wants hydro to supply 80% or more of Greenland's power.

岛政府希望水电可以占到岛内电能来源的至少80%。

Its performance exerts important influence on the quality of electric energy and operational reliability of the hydro power plants.

它调节发电机频率、运行方式以及水轮机功率的输出，其性能的好坏直接影响着电能品质和水电站的安全运行。

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％。