直流的

Based on the analysis of three-dimensional power conductor for DC arc furnace, the electric arc deflection model was set up and the control system of the arc direction was configured. According to the bus bar distribution at the bottom electrodes cooled by water, the arc direction control principle and its configuration were described, The simulation results show that the control system can restrain the electric arc deflection and control the arc direction.

在分析直流电弧炉三维导体布置的基础上，建立了直流电弧的偏工以此作为电弧位置控制的依据，针对水冷钢棒式底电极型的直流电弧炉，阐述了其电弧位置控制的原理和系统组成，并进行了仿真研究，结果表明控制系统可以有效地纠正电弧的偏向总是并可控设定点自由控制电弧以位置。

The configuration scheme of lightning arrestor protection for converter station, the principle of insulation coordination and overvoltage protection strategy for converter station are analyzed; the parameters and characteristic of lightning arresters are calculated; after analyzing the overvoltage protection for equipments and insulation level of equipments in detail, the discharge voltage of air clearances in converter station is given preliminarily.

自2005年国家电网公司部署建设±800kV直流特高压输电工程以来，组织国内外直流专业公司、科研院所、设计单位开展了广泛的研究工作[1-5]。从主接线方案的比较、户内外直流开关场的选择到绝缘裕度的确定，都从绝缘配合设计的角度进行了研究和比较，取得了大量研究成果[6-11]。

The DC and AC attenuator circuits provide ranging for the AC and DC functions.

直流和交流衰减器电路提供直流和交流功能的量程切换。

This invention relates to a DC linear motor digital controller including a central processor circuit, a data memory, a program memory, an A/D conversion circuit, a D/A conversion circuit, a linear shift orthogonal code pulse signal circuit, a signal isolation circuit, among which, the center processor circuit is composed of a special DSP chip controlled by the motor, a complicated programmable logic device CPLD combining with a peripheral expanding circuit, said digital controller fully utilizes the motor to control the special DSP chip to integral DSP kernel CZXLP and the rich external circuit in a single chip to make up of a digital controller for controlling high frequency response DC linear motor with small volume, low dissipation and high reliability.

高频响直流直线电机数字控制器，属于电机自动控制技术领域，目的在于获得快速、高精度往返运动的控制效果，实现高频响直流直线电机的精密位置跟踪控制功能。本发明包括中央处理器电路，数据存储器，程序存储器，A/D转换电路，D/A转换电路，直线位移正交编码脉冲信号电路，信号隔离电路；中央处理器电路由一个电机控制专用DSP芯片，复杂可编程逻辑器件CPLD，结合外围扩展电路组成。该数字控制器充分利用电机控制专用DSP芯片将高性能DSP核C2xLP和丰富的功能外设电路集成在单个芯片上这一特点，构成了一个体积小、功耗低、可靠性高和功能比较齐全的高频响直流直线电机控制用的数字控制器，使系统的整体成本大大降低。

Starting from the steady-state performance of three-phase fully-controlled rectified circuit, which is with large inductive load, we take the front two items of the Maclaurin series of the DC voltage average as approximate formula, with considering of the effect of the AC-side inductance first, and further effect of AC resistance on DC voltage and commutation angle.

本文从带有高感性直流负载的三相全控整流电路稳态工作的物理情况出发，首先考虑了交流侧电感的影响，进而考虑交流侧电阻对直流电压、换相角的影响，将直流电压的平均值用麦克劳林级数表示，取前两项作近似，得出了实用的解析计算公式，并给出了计算步骤，实验证明该结果具有较高的精度。

Above all by hand in dc network to the coupling between concerns and be changed stream implement changeover equation, derivation gives rectangular coordinates to fasten matrix of the Jacobi that makes dc system, Hessian, the means that offers section to seek solution in the light of the change that makes dc system control fashion next begs solution voltage to stabilize the usable transmission ability below tie condition.

首先由交直流网络间的耦合关系和换流器转换方程，推导出直角坐标系交直流系统的Jacobi、Hessian矩阵，然后针对交直流系统控制方式的改变提出分段求解的方法求解电压稳定约束条件下的可用传输能力。

This invention relates to a cascade multiple zero-type matrix rectifier, in which, a general input filter is connected between a net and a step-down transformer to get sine-wave input current, the step-down transformer includes n secondary windings with Yn spliced mid lines, the phase of all the three-phase windings is the same, the rectifier array is arrayed in a 1 row x n lines by n zero-matrix rectifier units, each line of which is connected with the seconday winding of the step-down transfornmer, and the outputs of the rectifier units are serial orderly to form a DC output, the general controller is responsible for regulating work of the entire system and connected with the branch controllers by signal cables to control the work of the rectifier units in the array.

本发明涉及一种级联多重化零式矩阵整流器，总输入滤波器连接在电网与降压变压器之间，滤波得到正弦波形的输入电流，降压变压器有n个Yn接带中性线的次级绕组，所有三相绕组相位相同，整流器阵列由n个零式矩阵整流器单元排成1列×n行的阵列，阵列中每一行与降压变压器的一个次级绕组对应连接，阵列中整流器单元的输出依次串联，形成一路直流输出，总控制器负责控制调节整个系统的工作，并通过信号电缆与各个分控制器联络，控制整流器阵列中每个整流器单元的工作。本发明由低压小功率的变换器串联得到幅值可调的高压直流电源，同时在电网侧得到位移为零的输入电流，具有网侧四象限运行能力等优点，适用于中高压直流供电领域。

During the process of solving power flow, the incremental transmission loss of each node can be easily obtained by means of simply solving the transposed matrix of original n-order matrix.

介绍了一种基于直流潮流的网损微增率新算法直流雅可比矩阵法，该方法以直流潮流为基础，引入虚拟网损负荷变量并构造出带有松弛负荷变量的有功不平衡方程雅的可比矩阵，在解潮流过程中只需求解n阶矩阵的转置矩阵，即可获得各个节点的网损微增率。

The harmonical influence due to the HVDC transmission lines on the AC line protection s using of different principles was analyzed theoretically and experimently.

由于三峡工程将把大容量的高压直流输电系统与交流电网连接起来，形成交直流混合运行的电网，这样运行的电网使得靠近换流站的交流线路保护将受到高压直流输电的强烈干扰。

The expert system, worked on rule, adopted the discharge signal and DC leakage current value as its characteristic parameters, and then diagnosed the insulation state of DC feeder cable by the values of the characteristic parameters.

直流馈出电缆绝缘诊断专家系统采用基于规则的专家系统实现，系统通过采用数据处理后提取的放电信息，直流泄漏电流幅值信息作为电缆绝缘性能诊断的特征参数，进而根据所获得的特征参数值来进行直流馈出电缆绝缘性能的判别。

We will see more and more activist government policies that distinguish economic activities according to the nationality of the actors.

我们将看到越来越多激进的政府政策，这些政策根据企业的国籍来区分经济活动。

If we can prove the independence of an axiomatic system, then we can guarantee the conciseness of this system, ie.

如果能够证明某个一阶谓词系统的独立性，那么就能够保证该系统的建立是精炼的，即没有任何一条公理或推理规则是多余的。