电压

The RMS—to—DC transformation is used for collecting virtual value of Ac. The voltage election elects the range of voltage. The analog—to—digital transformation realize transformation of measured voltage to corresponding digital figure. Finally the Sample Digital Display Ac Millivoltmeter is obtained.

其中RMS/DC专用芯AD637用来采集交流有效值转换，电压范围选择模块选择电压量程，模数转换使测量电压转换，最终得到所要求的数字显示交流毫伏表。

There are two loops in the control circuit which the feedback of the output voltage is the outer loop. In this loop there is a voltage error amplifier, a squarer, a divider and a multiplicator.

控制电路采用双闭环，外环输出电压反馈构成电压环，由电压误差放大器和一个平方器，一个除法器，及一个乘法器构成。

When the amplifier output is in either the positive or negative saturated state, the positive feedback network provides a voltage at the non-inverting input which is determined by the attenuation of the feedback loop and the saturation voltage of the amplifier.

不论放大器输出是正是负，只要OP达到输出饱和状态，OP正反馈路径就会在OP同相输入端加上一个电压，该电压的大小由OP正反馈路径的衰减和OP输出饱和时的电压共同决定。

When numberical reading of the voltmeter is available, the power of each phase can be measured through the alternation switch of the voltmeter.

电源部分接有电压表，当控制台有电压读数以后，可通过电压转换开关1HK测量各相的电。

The realize method of ITC strategy in FSTP induction generation system is studied. In order to improve stable performance of FSTP induction generation system, SVM-ITC (ITC based on space vector modulation) is investigated. Creation method of reference voltage vector which includes change trend and magnitude information of flux link and torque is presented. Because there is no zero voltage vector in four-switch system, a method which employs opposite vector in equal time to replace zero voltage vector is proposed. Two vector modulation schemes are presented.

为提高容错型四开关三相异步发电系统的稳态性能，进行了基于空间矢量调制的瞬时转矩控制研究，提出了包含磁链与转矩变化趋势与大小信息的电压参考矢量生成方法；针对四开关系统无零电压矢量的情况，提出用等时间相反矢量来代替零电压矢量的作用，并给出了两种矢量调制方案。

The paper presents the most efficient means to prevent the occurrence of resonance overvoltage often happening in extinction coil earth ed networks, namely,overcompensation pattern, after analyzing shift voltages in formal operation and broken wire condition.

摘 要：针对消弧线圈接地电网中普遍存在的谐振过电压问题，分析了正常运行及断线故障时各种补偿方式下位移电压的大小，得出防止产生谐振过电压的首要方案是：消弧线圈采用过补偿运行方式。

In the proposed device to remedy the defect that overhigh withstand voltage of thyristors used in converter are needed due to the overhigh DC link voltage, a method to control DC link voltage is put forward, that is, a special control logic for full-controllable switching elements is designed to make them equivalent to half-controllable switching elements which are naturally turned on and turned off by triggering, then connecting such a half-controllable switching element in series with DC link the defect of overhigh DC link voltage is effectively solved.

为了克服该装置直流母线电压过高，因而对逆变器开关管耐压要求过高的缺点，提出一种对直流母线电压进行控制的方法。对全控型开关器件设计一种特殊的控制逻辑，使其等效为一个自然导通、触发关断的半控型开关器件，将该半控型开关串联在直流母线上，有效解决了直流母线电压过高的问题。

The methods of parametric calculation and circuit equation calculation are also introduced.

阐述了超高压电压互感器冲击电压分布计算的电路模型、参数计算和电路方程计算的方法，计算了三种不同结构的模型，并就这些结构的特点对冲击电压分布的影响进行了比较。

This peak voltage setting becomes the threshold used for calculation of the voltage response curve for the instrument.

这个峰值电压设置为阈值电压，用来计算仪器的电压响应曲线。

In which VL is the lower voltage setting and VS is the voltage at the peak center, and

其中，VL是低电压， VS是峰值中心电压；其中，Vu是高电压

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。