切换

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。

Furthermore, the relationship between HO parameters and performance metrics is studied in detail based on RAU selection.

此外，在RAU选择的基础上，详细分析了2种切换方式中切换参数和切换性能指标之间的关系。

The fuzzy control method was adopted to design a fuzzy switching function to replace the sliding mode signum function, and the chattering phenomenon was restrained greatly.

针对滑模切换函数的高频"抖动"现象，采用模糊控制方法，设计了模糊切换函数，削弱了滑模切换函数的"抖动"。

The design method for the switching functional which leads to stable sliding modes is presented if the system is spectrally controllable.

摘要研究一类状态变量具有时滞的线性系统的变结构控制问题，指出传统的切换函数在时滞系统中应当是一个切换泛函，给出了在系统谱能控条件下具有稳定滑动模态的切换泛函的设计方法。

In order to realize the compatible communications system between digital TETRA and analogy MPT1327. Communications protocol between digital radio and control center is defined. Emergency call software flow for TETRA and MPT module is designed, and also state information sending and receiving for TETRA and MPT module is designed in this communication system. By comparing several solutions, switch methods between analogy TETRA communications and digital TETRA communications are designed including manual-switch and soft-switch. In the article, coding module of receiving and sending equipments in TATT analogy TETRA communications is described, so that it can be compatible with NOKIA network equipments and it also can improve the availability rate of the trunk system. In order to realize the integration of digital TETRA communication and analogy MPT1327 communications, double- frequency antenna system is researched.

通过几种车载电台解决方案比较，设计了相应的模拟集群通信系统与数字集群通信系统的切换方法，其中包括人工切换和软切换，实现了模拟与数字集群兼容的一体化移动列车调度电台解决方案；为了实现数字集群通信系统与模拟集群通信系统以及NOKIA与TAIT模拟集群通信系统之间的相互兼容，设计了新的数字车载电台与控制中心之间的通信协议；系统设计了用于数字集群通信模块的紧急呼叫通讯流程，以及设计了用于模拟集群通信模块状态信息发送与接收流程，以满足列车无线调度的运营要求；论文还论述了对TAIT模拟集群收发设备编码模块的改造，使之能与NOKIA的集群设备相兼容，提高了集群设备的利用率，为在NOKIA模拟集群通讯模块停产后寻找了一种可替代的兼容解决方案；为了实现数字集群通信系统与模拟集群通信系统设备的综合，论文还探讨了本工作所需专用的双频段的天线系统。

The proposed inverter has a new auxiliary resonant commutation cell. It provides that all main switching power devices in the soft-switching inverter operate at zero-voltage-switching turned-on and the auxiliary switches operate at zero-current-switching turned-off. In addition, this thesis presents an improved control scheme to minimize the operation of auxiliary resonant circuit for efficiency improvement.

所研制之柔切式数位变流器，系利用新型辅助谐振单元，使主功率开关操作於零电压切换，辅助开关操作於零电流切换，在此也提出改善之控制方案，以避免多余的辅助开关切换，因此能有效降低谐振电流所造成的额外导通损失，以提升系统之效率。

A switching strategy and an algorithm which guarantee that the system is uniformly ultimately bounded are given.

给出了切换策略，以及使切换系统在此切换策略下是终极一致有界的算法。

Said invented method for and device adopt MCU or logic or logic chip detecting said ringing current signal, backboard ringing current signal and mutual sent signal, and sequential control sequential control, avoiding switch device hard switching and arcking, raising switch device and backboard reliability.

本发明方法及装置通过采用MCU或逻辑芯片检测本板铃流信号，背板铃流信号和互送信号，并采用时序控制，避免了在铃流开机和切换时的开关器件硬切换，以及铃流的在开关电路切换时的拉弧，提高了开关器件的可靠性；而且把开关电路从通讯设备插框背板转移到单板上来，提高了背板的可靠性，降低了后续的维护和检修困难。

When the system is composed of unstable subsystems and stable subsystems, it is proved that if the activation time of stable subsystems is relatively large compared with that of unstable subsystems, then the boundness is guaranteed.

当切换系统中含有不稳定子系统时，证明了当切换规则满足一定条件时，仍可保证切换系统是有界的。

By switching with these two brakes and the clutch, the vehicle may be switched in different driving modes; and controlling the rotation speed of the inner rotor can control the switching of the electrical stepless speed variator in different mixed driving modes.

切换两个制动器(9、5)，开闭离合器，车辆可在两种混联混合动力模式和纯电动模式之间自由切换。控制内转子(2)的转速可控制电力无级变速器在混联混合动力模式和并联混合动力模式间切换。

Fancy gold-plated dangling earrings with facetted White Opal crystals.

花式镀金悬垂耳环与facetted白欧泊水晶。

This essay chooses the study aim from biology teachers in middle school in Shi Jiazhuang which tells us that most of the middle school biology teachers in Shi Jiazhuang have the"burnout", lower successfulness, individualize.

本文选取石家庄市初中生物教师作为研究对象，运用问卷调查的方法对石家庄市初中生物教师职业倦怠的现状进行调查，调查结果发现，石家庄市初中生物教师这一群体普遍存在职业倦怠，情感枯竭程度偏高，成就感偏低，去个性化程度最为严重。