电压

To improve the stability of Arcjet discharge plasma in low current and high voltage mode, research on the demand of output characteristics of Arcjet Power Conditioning Unit was conducted. In this paper, based on PWM invertors and current mode control, using MOSFET as the main power device, an Arcjet Power Conditioning Unit was developed. Through adding a closed loop feedback circuit of output voltage, it can make the output characteristics of PCU be positive resistance to ensure the stability of Arcjet discharge plasma. The experiment indicates that this PCU can make Arcjet engine work at high voltage mode (100 V, 10 A) and ensure the stability of arcjet discharge plasma. Finally, it provides the experimental data of Arcjet when working.

为了解决小电流、高电压下电弧火箭等离子体的稳定性问题，研究了电弧火箭发动机对电源调理单元的输出特性要求，基于逆变电源脉宽调制技术与峰值电流型控制原理，以MOSFET为主功率器件，研制了一台电弧火箭电源调理单元，给出了Arcjet工作时的实验数据，通过增加PCU输出电压的闭环反馈电路，可以使PCU的输出外特性呈现正阻性，保证电弧的稳定燃烧，实验结果表明，该电源调理单元能使电弧火箭发动机达到高电压工作模式(100V， 10A)，保持电弧工作的稳定性。

The objective of design optimization for the current loop is to maximize the cross-over frequency. The results show the stability is improved and the capability of suppressing the switching noise is far better than the original. The objective of design optimization for the voltage loop is to minimize the gain of the line ripple voltage.As a result the bandwidth minishes obviously and optimization design excelles in restraining the ripple.

主电路以总体积最小为优化目标，优化结果表明电路的体积减少了0.5%；电流环以开环穿越频率最大为目标，优化结果表明电流环的稳定性能得到了改善，开关噪声抑制能力明显优于优化前的；电压环以线纹波电压增益最小为目标，优化结果表明电压环的带宽明显减小，纹波抑制能力远远优于优化前的。

The output is measured by a voltmeter or detector, such as precision voltmeters, ac measurement standards, ac/dc transfer standards, or thermal voltage converters, fitting them to a wide variety of metrology applications.

输出电压的测量或检测器，如精密电压表，交流计量标准，交流/直流转换标准，或热电压转换器，适合他们的各种计量应用。

The voltage converted into 0～5 V using convering circuit can be used directly by microprocessor ,and con2 verted into digital signals by A/ D converting. So this simplifies the design of the circuits.

通过电压转换电路可以将- 10～+ 10 V 的输出电压转变成为0～5V 的电压，便于带有A/ D 转化电路的单片机系统直接进行A/ D 转换，简化了电路设计。

In order to solve this problem, a control strategy is developed. A control algorithm to suppress negative sequence current through ASVG caused by slight asymmetry of system is also developed based on the modeling method in function of switchings and the definition of instantaneous negative sequence voltage. The ASVG can generate a negative sequence voltage component against that in the system while it generating positive sequence voltage with this algorithm.

在系统轻度不对称时，本文提出了通过控制ASVG触发脉冲使其产生与系统电压负序分量大小和相角完全相同的负序电压以抵消系统电压负序分量，从而抑制ASVG负序电流的方法，并用&开关函数&建模法给出了具体的控制算法。

An injection type shunt hybrid active power filter was analyzed, it can suppress harmonic currents and compensate high capacity reactive power, nevertheless, a sharp boosting on DC-side voltage was found in application. Based on the analyses of the reasons, different solutions was proposed such as adoption of main circuit of multiple performances, the use of hysteretic control method, fore-feed control of reflowing current or direct control on DC-side voltage without a rectifier to supply.

研究一种兼具大容量无功补偿能力的注入式并联混合有源滤波器，并分析其在工程应用中发现的直流侧电压抬升现象及这种现象产生的原因，在此基础上提出从采用多重化主电路结构、滞环控制法、回灌电流前馈控制法和脱离整流电源直接对直流侧电压进行控制等几个方面来抑制直流侧电压抬升的方法。

Supply Taiwan 3 assist energy-saving axis sheds import environmental protection fan FP-108K brand: 3 assist dimension: 2220 × of 20 × 60mm voltage: AC230V wind force: 360CFM power: 46/40W revolution: 2850/3400RPM noise: 50/53DB producing area: Material of the casing outside Taiwan is qualitative: Aluminium alloy motor: Overspread extremely motor structure; Frame: Die-casting of aluminium alloy of the black lacquer that bake is anticorrosive, water-vapor proof structure; Wind leaf: High temperatu

供给中国台湾三协入口环境保护节省能源轴流风机FP-108K品牌：三协大小：220×220×60mm电压：AC230V风力：360CFM码率：46/40W转数：2850/3400RPM噪声：50/53DB生产地方：中国台湾外框材料：铝合金发动机：罩极发动机构架；范围：黑烤漆铝合金压铸防止腐败、防湿构架；风叶：耐温高塑胶扇叶；轴承：高细度、长命命双滚珠轴承；绝缘：漆包线使用B级绝缘，耐温高80慑氏度；绝缘电诅：800兆欧以上；耐电压：泻走电流0.5mA，耐电压2300V/1分钟；运行温度：-25慑氏度到+55慑氏度周围的环境温度40度时课接连着工作3200钟头储存温度：-25慑氏度到+55慑氏度

This paper describes the importance of neutral point connection in the secondary circuit of voltage transformer reflected in relay ant-accident measures.It gives the test methods in detail to.The solution is also given.

本文详细描述了判断电压互感器中性点电压异常的试验过程和方法，提出了电压互感器二次回路中性点未接地的解决办法。

The coil voltage and duration of closing course is derived from calculation result of the dynamic characteristic.

根据新型永磁机构在不同线圈电压下的动态特性进行计算结果，得到线圈的吸合电压，并根据该电压下动态特性计算结果确定吸合时间。

Since the voltage not only has relationship with both the reactive power and the balance of reactive load, but also relies on the structure of network and capability of voltage regulation, the system takes all the factors above into consideration and adopts the methods as follows: realizing grading control and management according to the voltage level and region partition, realizing jointly regulation and information pool by the application of advanced software in local and central station, realizing the optimal control of reactive voltage based on the measurement data from the regulative automation system and the angle of the whole system, realizing the exact application of reactive compensator and the on-load tap appropriate changer for voltage regulation transformers , and realizing the balance of reactive voltage in local site.

随着调度自动化系统的日益普及，以及越来越多的电网中的有载调压分接开关和电容器补偿装置投入使用，本课题研究开发基于分级递阶的地调/中心站模式无功电压控制系统，由于电压既与无功功率和无功负荷平衡有关，又与电网结构、调压能力有关，所以系统考虑电压等级、按区域实施分级控制、分级管理，利用中心站和地调的电力系统高级应用软件的作用实现众多装置的联合调整，信息共享。

Shop assistant: Please check at the door.

店员：请您到门口柜台交费。

In the end, transportation of PAHs in the environmental matrix was preliminarily investigated and discussed according to PAHs data of soils and sediments from a certain region in Shanghai. The result indicated that there are two or more pathways on PAHs transportation in the environmental matrix.

最后，对上海特定地区内PAHs在环境介质中的迁移径途进行了分析讨论，结果表明上海市土壤和沉积物等环境介质中PAHs的迁移存在多种途径。