电压

The voltage distribution of Y-type insulator strings for AC/DC 500 kV transmission line is measured by sphere gap method and corresponding measures are adopted to reduce the impacts of environmental factors on measured results, thus the voltage distribution curve of Y-type insulator strings under AC/DC 500 kV conditions.

采用球隙法测量了交、直流500 kV输电线路中Y型串绝缘子的电压分布，采取相应措施减小了环境因素对测量结果的影响，得到了交、直流500 kV电压下Y型串的电压分布曲线。

When heavy load is transmitted along a 750 kV transmission line, the connected shunt reactors can lead to big voltage decreasing, so transmitting capacity of line is limited greatly.

为解决线路传输能力与抑制过电压的矛盾，分析研究了并联电抗器在抑制750kV线路跳闸过电压、加速潜供电弧熄灭以及抑制合闸过电压等方面的作用，并由此提出了750kV线路保护与并联电抗器之间动作配合关系。

Based on particular analysis of characteristic of presented scheme on different working condition, the setting rule is given.

利用正、反方向故障时补偿电压与母线电压故障分量的变化规律，本文提出了基于补偿电压故障分量的方向判别原理。

Then, flaw of existing full-digital voltage commutation method is pointed out after the change of the critical area which switch sequence will encounter corresponding to the variety of displacement angle at the input-side of converter has been explicated, then several rules have been presented and used to instruct detailed voltage commutati.

通过分析输入侧功率角变化对矩阵变换器全数字电压换流技术的影响，指出现有全数字化电压换流方案的缺陷，并提出新的改进原则，接着给出详细的数字化电压换流策略实现方法，分析新方法对变换器换流次数的影响。

Then, flaw of existing full-digital voltage commutation method is pointed out after the change of the critical area which switch sequence will encounter corresponding to the variety of displacement angle at the input-side of converter has been explicated, then several rules have been presented and used to instruct detailed voltage commutation method built. Increment of switches' commutation-times, thanks to the new method employed, is analyzed in succession.

通过分析输入侧功率角变化对矩阵变换器全数字电压换流技术的影响，指出现有全数字化电压换流方案的缺陷，并提出新的改进原则，接着给出详细的数字化电压换流策略实现方法，分析新方法对变换器换流次数的影响。

This thesis proposed the design and implementation of an ASIC for the motor control with DTC technology. Note that this ASIC is implemented by cell-based Design style with Verilog language.The basic principle of the Direct Torque Control is to select the switch sequence of the inverter. Those switches will control the magnetism and torque of the stator, to induce a fast response of the induction motor. Furthermore, the d-q axle's static coordinate, which is transferred from both the three-phase current and voltage, is used to compute the stator's magnetism and torque. By comparing with original values, those magnetism and torque will be calculated and set to new data. Then the switching table and the hysteresis controller are decided with the new data to generate a voltage vector and to control the stator magnetism and torque.

直接转矩控制的基本原理为经由侦测马达定子磁通与转子转速，来适当的选择变频器功率电晶体的切换状态，以获得快速且不易受外在环境影响的马达控制响应；首先，根据量测三相电流与利用变频器的切换状态取得马达的三相电压，将其转换至d-q轴静止座标，然后藉此估测马达的磁通量与转矩量，再分别与侦测的定子磁通量和转矩量比较后，得到定子磁通量与转矩量比较的结果，再利用DTC电压向量切换表(DTC Voltage Vector Switching table)，依定子磁通与转矩的比较值及马达所在的角度位置，来选择一个适当的电压向量，进而依切换顺序来激发功率电晶体，达到控制感应马达的目的。

For a voltage selector switch , the test voltage is to be based on the highest rated voltage.

对电压选择器开关，测试电压用最高额定电压。

There are some important and novel conclusions deduced: 1. The curve of resonance output vs excitation voltage shows that electrostatically excited resonator could be easily excited by low excitation voltage and could be well protected when overloaded due to the good structure design.

静电激励微谐振器谐振峰值与交流激励电压的关系曲线表明该谐振器在较低的电压激励下即可获得较大的振幅，同时该谐振器具有良好的过载保护功能，在用于精确测量时，必须保证激励电压处于该曲线的线性段。

The main purpose of this thesis is to research and develop three different kinds of battery chargers of resonant-switch converters. Starting with the zero voltage switch and the zero current switch converters, which employ the quasi-resonant converter technique, we gain the best parameters of the resonance components from the characteristic curve diagrams of these two converters. Then we design battery chargers based on these two structures and use them to experiment on lead-acid batteries.

中文摘要本论文之主要目的在於研制三种不同的共振开关式转换器蓄电池充电器，先探讨半共振式技术的零电压以及零电流转换器，利用这两种转换器的特性曲线图设计出共振元件最佳的参数值，以这两种架构作为蓄电池充电器，来对铅酸蓄电池做充电测试，经实验测得，零电压切换半共振式降压型转换器之充电器的开关在零电压的时候导通和截止。

The whole system, which is powered by a single 5V power, supplies steady core voltage (1.8V) and I/O voltage (3.3V) with high-efficiency synchronous step-down dc/dc converter TPS54314 and TPS54316, presents a power supply sequencing solution for dual supply voltage DSPs and includes a supervisor on the power supplies and reset circuit in order to make the system more stable and efficient.

整个供电系统采用单一的5V电源供电，用高效率的同步电压转换芯片TPS54314和TPS54316芯片分别产生TMS320C6711B DSPs的内核电压（1.8V）和周边I/O接口电压(3.3V)，同时巧妙地解决了两种供电的顺序问题，并增设了电源监控和复位电路，确保供电系统稳定、高效地工作。

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。