查询词典 harmonics

Steady-state harmonics and transient performance of the conventional static synchronous compensator controllers are first investigated. Based on the sensitivity analysis of the STATCOM output power, it is found that the voltage magnitude is more effective than the phase angle in controlling the reactive power output. An analytical approach to harmonic analysis of a STATCOM based on Bessel functions of the first kind is described.

本博士论文首先分析传统静态同步补偿器(Static Synchronous Compensator， STATCOM)控制器的优缺点，利用对静态同步补偿器输出功率的灵敏度分析，得知要控制补偿器输出虚功大小时，直接对静态同步补偿器输出电压大小作控制，会比对相角作控制来得有效。

Since the harmonic spectrum of ac-side phase voltage of PWM rectifier is influenced not only by pulse modulation style, but also by the parameters of close-loop adjustors, a three-phase voltage source inverter controlled by TMS320F2812 has been built to obtain the harmonics purely generated by SVPWM and verify the algorithm.

由于PWM整流器交流侧相电压的谐波频谱不仅与脉冲调制方式有关，还受到闭环调节器参数的影响，因此该文搭建了以TMS320F2812为控制核心的三相电压型逆变器系统以得到单纯由SVPWM产生的谐波频谱，并对该算法进行验证。

Since the harmonic spectrum of ac-side phase voltage of PWM rectifier is influenced not only by pulse modulation style, but also by the parameters of close-loop adjustors, a three-phase voltage source inverter controlled by TMS320F2812 has been built to obtain the harmonics purely generated by SVPWM and verify the algorithm. Power analyzer PZ4000 has been adopted to acquire experimental results.

由于PWM整流器交流侧相电压的谐波频谱不仅与脉冲调制方式有关，还受到闭环调节器参数的影响，因此该文搭建了以TMS320F2812为控制核心的三相电压型逆变器系统以得到单纯由SVPWM产生的谐波频谱，并对该算法进行验证。

It leads to higher harmonics amplitudes in lower frequency range.

它产生低频段的高振幅。

With the development of power electronics, nonlinear loads are widely used in power system, which bring about serious harmonics pollution and big current of reactive power. In the same time, the load including high-tech and high precision is developing rapidly, which ask for high quality power. In the other hand, the power net is becoming bigger, the disturbers between different parts of the power net becoming more serious.

随着电力电子技术的发展，越来越多的非线性负载投入电网中，谐波和无功对电网的污染越来越严重，同时，高精密负荷的比重迅速增大，对整个电网电能质量要求越来越高；另一方面，电网的并网规模越来越大，电网各部分之间的干扰也不断加重，这些都严重的威胁着用户电能质量和电网的运行安全。

Unfortunately, too many engineers focus on the effect of harmonics on other electronic devices and tend to overlook the effect of the extra harmonic current that their electrical distribution systems need to carry.

不幸的是，太多的工程师都把注意力放到了其他电子设备产生的谐波干扰上，却往往忽略了电气分布系统载有的额外的谐波电流的影响。

Bartok created a special musical notation such as staffs,Bartok-devised key signatures, accidentals, 1/2pedal, harmonics. Some symbols are used to separate phrases, such as "│",",", fermata, etc., which is not common. Among all,"│" symbol is used most frequently to separate phrases.

巴尔托克独特的记谱法，在《小宇宙》中表露无遗，多元的谱表应用、方便弹奏者视谱的巴尔托克式调号记谱法、临时记号的普遍使用，以及其他特殊记谱方式如1/2踏板记号、泛音音符与分句记号的标示如「|」、「，」与「」等，为二十世纪音乐创作带来丰富的泉源。

Input Power Factor Correction: The rectifier shall be power factor corrected so as to maintain an input power factor of 0.98 lagging to unity at all load levels to ensure generator compatibility and avoid reflected harmonics from disturbing loads sharing the utility power.

UPS模块的设计须可使之作为双变换和在线反向输送系统在下列模式下正常工作。A。正常模式：逆变器须可不断向临界负载输电。整流器/电池充电器须从交流电源获取电能并向逆变器供电，同时以浮动方式给电池充电。

Experimental results of the second harmonic sound pressure level(SPL2)curves in frequency domain show that Prof.MAA's theorydescribes the behavior of the second harmonics satisfactorily in whatis called "Steady Region" of standing wave field.

频域内，大振幅驻波场二次谐波声压级曲线的实验结果，确认马大猷教授的理论为驻波场&稳定区&的极好描述，所提理论在本实验研究中，得到了肯定结果。

It is therefore becoming most significant and valuable to do research on how to reduce capacitance as small as possible or even remove capacitor and how to settle relative issues and to eliminate low order harmonics due to minishing capacitance or removing capacitor.

因此，研究如何减小甚至去除逆变器直流侧电容，以及解决因其产生的低次谐波和相关问题，具有十分重要的理论意义和实用价值。

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％。