查询词典 constant voltage

Based on varying process of generator terminal parameters after excitation fault, shortages of excitation protective principle of static stability boundary and asynchronous impedance boundary are analyzed. It proposed that excitation fault research relates to large-disturbance stability. Because dynamic power-angle character of generator after excitation fault is non-sinusoidal, there are differences between dynamic power-angle character and static state power-angle character. So it isn't ideal to protective operation result based on small-disturbance stability and static stability boundary criterion. At the same time, it proposed that asynchronous boundary impedance criterion is a constant reactive power circle moving adown j Xd′. It can ensure complete loss-of-excitation generator measuring impedance enter into the circle, but can't ensure the other condition measuring impedance including impossible losing synchronism enter. So loss-of-excitation protection would be maloperation when system voltage drops short and recovers or generator rejects load.③Based on stability principle, it puts forward setting conditions and calculation method of generator loss-of-excitation protection by direct measuring power-angle.

以励磁故障后发电机端的相关参数的变化为基础，通过对以静稳定边界和异步阻抗边界作判据的两类三种现行励磁保护在原理上存在的缺陷分析，发现：励磁故障是一个大干扰稳定性问题，励磁故障后的发电机的动态功角特性与静态功角特性有很大的差异，已远非正弦曲线，因此基于小干扰稳定性原理、以静稳定边界作判据的保护必然动作不理想；异步边界阻抗判据是一个下移j Xd′的等无功阻抗圆，它可以保证完全失磁后的发电机测量阻抗能进入该阻抗圆，但不能保证完全失磁之外的其它状态不会进入该阻抗圆，因此在系统电压短时下降或发电机突然甩负荷等情况下可能启动该保护使之误动。

When the system is at work, IF output power is achieved through adjusting inverter trigger angular frequency, which can always make the power out put be in the biggest state . Through the effect of the voltage and current closed-loop ,IF power achieve constant power output.

由于系统在工作时，中频电源的输出功率是通过调节逆变触发角频率来实现的，这样就可以始终使输出的功率处于给定的最大状态，并且通过电压和电流闭环作用，使中频电源达到恒功率输出。

Results from the experiment on an EHD experiment bench show that condensation heat transfer in a horizontal tube responds strongly to the EHD technique; the effect is greater for lower heat flux but lesser for higher heat flux; the enhancement coefficient is proportional to the exerted voltage for a constant heat flux and reaches as high as 156% under the conditions described in this paper.

在电流体力学强化传热试验台上进行了水平管内凝结传热的强化试验研究，结果表明，EHD技术对水平管内的凝结传热有明显的强化效果；低热流密度时，强化效果较好，增大热流密度时，强化效果减弱；热流密度维持不变时，强化系数随强化电压的升高而增大；在本试验条件下，对凝结传热的最大强化系数为 1 5 6%。

METHODS: On the basis of PMT passive voltage biasing circuit, Bipolar Transistor or Field Effect Transistor were used. Additionally,"adjustable constant current technology" was adopted to avoid the effect of temperature on circuit.

在电阻型光电路倍增管偏置电的基础上，增加双极型晶体管或场效应晶体管构成有源光电倍增管偏置电路；并采用可调恒流技术，以解决温度对电路的影响。

This is because McIntosh maintains the voltage from each screen grid to cathode constant by the unity coupling between the two halves of the bifilar winding.

这是因为麦氏是用单一耦合双线并绕的两半部分来维持廉栅极对阴极的电位恒定。

On the basis of the above results of detecting methods, the instruction signal calculating circuit is designed according to i〓, i〓 calculating mode. Compensation current generating circuit is also designed and implemented. Its current following circuit is designed according to the instantaneous value comparing mode that used constant time control. The source current detection based control mode and composite control mode and their implementation are firstly introduced in our country. The method and the principle of dc side capacitor voltage control are explained clearly.

根据检测方法的研究成果，采用i〓、i〓运算方式构成并联型电力有源滤波器的指令电流运算电路；对补偿电流发生电路进行了电路设计和实施，其中电流跟踪控制电路采用电流跟随性能好、可靠性高的定时控制瞬时值比较方式；在国内首次研究并实施检测电源电流控制方式和复合控制方式；清楚地阐明了并联型电力有源滤波器直流侧电压控制的原理和方法，并在装置中实施。

The product of the input voltage and the charging time of C1 is constant.

输入电压和C1充电时间的乘积为常数。

As an assembled nanostructure, nanoelectrode ensembles or arrays present many advantages such as enhanced mass transport, lower double layer charging current, short time constant, lower electrolyte voltage drop, higher ratio of signal to noise, as well as good maneuverability, with high sensitivity and reliability in electroanalysis. Therefore, they have found broad applications in a variety fields including the study of electrochemical theory, biosensor, electrocatalysis and electrode materials in high energy chemical batteries.

纳米阵列电极作为一种人工组装的纳米结构体系，具有高传质速率、低双电层充电电流、小时间常数、小IR降及高信噪比、可操作性强和测量灵敏度高等优势，因而在电化学理论研究、生物传感器、电催化材料和高能化学电源电极材料等方面具有广阔的应用前景。

In order to eliminate the influence caused by the nonminimum phase characteristic of a common Boost DC／DC converter, Viswanathan K has proposed a novel tristate Boost DC／DC converter. For enhancing performance, the statespace averaging model of this converter was first presented in this paper. Due to the nonlinear nature in this model, an inputoutput feedback linearization technique was adopted, and a complete controllable linear system was obtained. Then a statefeedback control strategy was designed based on this linear system. Simulation results show that the proposed control strategy can assure constant output voltage in a wide range, so as to realize the stability of the system during large fluctuation of power supply and load disturbance. Good dynamic performance can also be achieved.

针对 Viswanathan K为消除普通BOOST DC／DC变换器的非最小相位特性而提出的三态Boost DC／DC变换器，为进一步提高这种电路拓扑的性能，在建立了变换器状态空间平均模型的基础上，针对其多变量、非线性特点，采用输入输出线性化将其转化为一个完全可控的线性系统，在此基础上应用现有成熟的线性控制策略进行了控制系统的设计，并且采用MATLAB进行仿真验证，结果表明：这种非线性控制策略可以确保输出电压在大范围内恒定可调，且即使存在大范围扰动(输入电压和负载变化均较大)的情况下，系统也可以确保稳定性和良好的动态性能。

Disadvantage of this device is high voltage, in order to reduce the operating voltage to achieve the purpose of actual use, screening of high dielectric constant material as the dielectric layer material is topic of future research.

缺点是工作电压偏高，需要进一步筛选出介电系数高的物质来作为介电绝缘层材料，以便降低工作电压，达到实际可以使用的目的。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。