转换开关

And due to the nature of the data acquisition, three data acquisition circuit board are adopted. They are voltage to digit data converting circuit board, current to digit data converting circuit board and digit data input/output circuit board. These circuit boards are used to acquire the main running parameter of the multifunctional experimentation equipment and to control the output of alarm message.The monitor and control program is developed on Delphi5.0 which is an excellent product of Borland Corp.

数据监控系统的硬件以一台工业控制PC机为核心，并根据采集信号的性质配置了电压-数字量转换板、电流-数字量转换板及开关量输入／输出板，对实验台的主要运行参数进行采集并进行报警控制；监控系统的软件以BORLAND公司的Delphi5.0作为开发平台，采用了面向对象的设计方法，运用了多线程、数据库等技术，做到了界面美观、操作方便。

The transfer function of the LLC resonant converter can be obtained by using the circuit impedance, ratio of resonant inductance, and quality factor. With proper selection of the resonant tank and modulation of the operation switching frequency, the proposed circuit can achieve zero voltage switching, stabilize the output voltage, and then reduce the switching loss.

其后级之半桥LLC谐振式转换器藉由推导电路阻抗、谐振电感比例值与品质因数得到转移函数，以及利用适当的谐振电路的设计与切换频率的调变的方式达到输出电压稳定，并且令功率开关具有零电压切换之功用，以降低功率开关的切换损失。

The physics of the noise mechanism that is based on pair of active first detector understands, noise was used to eliminate a technique in circuit, twinkle in order to reduce what the switch in Gilbert first detector is in charge of noise, introduce an additional inductance and switch to be opposite in all the parasitism capacitance of source node is syntonic, the sonic system of a confusion of voices that improves whole circuit is counted and change gain to wait for crucial function index.

基于对有源混频器的噪声机制的物理理解，电路中采用了噪声消除技术，以减少Gilbert型混频器中开关管的闪烁噪声，并引入一个额外的电感和开关对共源节点的寄生电容谐振，改善整个电路的噪声系数和转换增益等关键性能指标。

Based on two kinds of control strategies of VSR under unbalanced grid condition,the introduction of a new VSR control strategy featuring undamped -oscillation that simplifies the controller structure and effectively improves VSR"s performance under unbalanced grid condition.· A systematic description of the state switching in trilogic PWM signal generation of three-phase CSR by using the conversion between bilogic and trilogic switching functions.· Referenced to the CSR"s trilogic PWM signal generation, an approach to achieve low-stress natural commutation of switching devices by reshuffling the vector composition sequence, resulting reduced switching loss.

在研究了两类电网不平衡时的VSR控制策略基础上，提出了一种新型的基于无阻尼振荡控制器的VSR不平衡控制策略，在简化控制结构的同时，有效地改善了电网不平衡时的VSR控制性能；·通过二、三值逻辑开关函数间的转换，系统地描述了三相CSR三值逻辑PWM信号发生中的状态切换；·结合三相CSR三值逻辑PWM信号发生规律，提出了通过调整矢量合成顺序而使功率管获得自然换相的低电压应力SVPWM控制，从而有效地降低了功率管的开关损耗。

Referenced to the CSR's trilogic PWM signal generation, an approach to achieve lowstress natural commutation of switching devices by reshuffling the vector composition sequence, resulting reduced switching loss. With the background of and well instanced by the Xinjiang Autonomous Region's Key SciTech Project"Solar Photovoltaic grid-connected inverter", the dissertation work implemented the new approach of a grid-connected PV inverter that was of single-phase VSR topology and with MPPT .

在研究了两类电网不平衡时的VSR控制策略基础上，提出了一种新型的基于无阻尼振荡控制器的VSR不平衡控制策略，在简化控制结构的同时，有效地改善了电网不平衡时的VSR控制性能；通过二、三值逻辑开关函数间的转换，系统地描述了三相CSR三值逻辑PWM信号发生中的状态切换；结合三相CSR三值逻辑PWM信号发生规律，提出了通过调整矢量合成顺序而使功率管获得自然换相的低电压应力SVPWM控制，从而有效地降低了功率管的开关损耗。

The stations include converter transformers as well as air-insulated and gas-insulated switchgear.

转换站包括转换变压器以及空气绝缘和气体绝缘开关。

The transfer function of the LLC resonant converter can be obtained by using the circuit impedance, ratio of resonant inductance, and quality factor.

其后级之半桥LLC谐振式转换器藉由推导电路阻抗、谐振电感比例值与品质因数得到转移函数，以及利用适当的谐振电路的设计与切换频率的调变的方式达到输出电压稳定，并且令功率开关具有零电压切换之功用，以降低功率开关的切换损失。

Especially, more attention is paid to the blocking performance of the router with limited wavelength convertible capability. And it is seen by the numerical computing that low conversion degree of the wavelength converter is more realistic to construct a wavelength router system with accurately tunable devices not used, not only switching time is to be minished, but also the complexity of carrying out in engineering is reduced.

尤其在受限波长转换条件下的配置优化分析，可看出波长路由器无需可调谐器件，也能获得灵活的波长转换能力，不但可避免波长路由器因为精确调谐所开销的时间，而且所有的控制均为简单的开关控制，可降低工程实现的复杂度。

In this design, hardware circuit adopts liquid crystal screen and program sensor keyboard as interactive interface, 96 single-chip as chief controller, analog multi-circuit switch as transmission signal. To improve conversion accuracy, I also bond an analog to digital converter%26mdash;AD1674, so the programs mainly contain the display program design of the LCD module, the key-board control program and cyclical monitoring of various parameters and so on.

本文的硬件电路采用液晶显示屏和触摸式键盘作为人机交互界面，用80C196KB作为主控制器，用模拟多路开关传输信号，并且为了提高转换精度，外接了模数转换器AD1674，所以本设计的程序主要包括液晶显示程序、键盘管理程序、控制巡回采样等模块。

Adopt one kind of design plan that PLC controls in the protection the main body of a book has been introduced succeeding an electricity in electric system, that capital is designed time is that the KV circuit imports 10 mainly , change into 380 V voltage grades, before the PLC front and back add front to passage and the queen to passage, change before to passage middle course electric current , voltage a train of, the wave filtering the general is exchanged changing waking up with a start for direct-current, the entering carrying out comparison and switch amounts again , controlling conducting entering PLC, by PLC, The malfunction signal is shown out by lamp light or the alarm signal.

本文介绍了在电力系统继电保护中采用PLC控制的一种设计方案，本次设计主要是将10KV线路输入，转化为380V电压等级，在PLC前后加入前向通道和后向通道，在前向通道中经过一系列的电流、电压转换，将交流转换为直流，进行滤波，再进行比较和开关量的输入，传入PLC，通过PLC的控制，将故障信号通过灯光或者报警信号表现出来。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。