过电压

For the first time, it is revealed that the low frequency component of secondary arc current of series capacitor compensated transmission lines has great influence on extinguishing secondary arc and success ratio of singlephase reclosing.

3通过理论分析和仿真计算，讨论了串补装置对输电线路工频过电压、操作过电压和雷电过电压的影响，并对串补电容器组在以上过电压作用时的工作条件进行了计算分析。

The scheme can effectively restrict operation over-voltage, and has the function of the lightning arrester, and serves as a reference for other projects.

电力系统中普遍存在过电压情况，根据引发原因主要有以下几种：谐振过电压、操作过电压和雷电过电压。

This paper deals with the surge protection of a 220kV H—GIS and analyzes the effects of metal oxide surge attesters on reducing the incoming lightning overvolrages by means of numercal method Meanwhile, there is a kind of over-voltagey which may be rather critical for GIS, e·g·the switching surges with extremely high frequeuly produces by GIS-G switching-off of some loadless duses.

本文讨论220kV混合式GIS变电站过电压保护，用数值计算方法分析氧化锌避雷器对降低过电压的作用，并讨论了有一种类型的过电压可能对GIS要求更为严格，即在主回路中用GIS隔离开关切除空母线引起某些高频操作过电压，因此在绝缘配合时要相应考虑。

On the base of practical transformer substation main connection, electric components and system circuit model are first formed in the paper; analyze vacuum arc characteristic and medium resume are analyzed, then, according to vacuum chamber physical process of switching AC arc, resume process are divided into three stages: sheath development, neutral particles diffusion and static characteristic, with that, calculating model of medium resume strength is erected and applied in the computing of vacuum circuit breaker interrupting transform overvoltage; In the paper, Saber software is used to simulate a whole switching process; As follows, overvoltage characteristic of vacuum circuit breaker switching no load and load transformers, kinds of influence factors are analyzed in detail; At last, vacuum circuit breaker switching capacitance group overvoltage formative causes and electrode refining for lessening reignition are discuss.

本文针对中低压变电站的实际主接线建立各电气元件及系统的电路模型；在真空电弧的特点及间隙的介质恢复特性上，依据真空断路器灭弧室分断电弧的物理过程，将真空电弧熄灭后的恢复过程分为鞘层发展、中性粒子扩散和静态特性三个阶段，建立了相应的介质恢复强度的计算模型，应用到切除变压器操作过电压的计算中；采用Saber仿真软件模拟计算真空断路器切除变压器操作过电压；并分别对真空断路器切除空载及负载变压器操作过电压的特点与影响操作过电压的各种因素做了详细的分析；最后简要分析了真空断路器开断电容器组过电压的形成原因及为减少重燃的电极老炼措施。

But in practical operating, overvoltage caused by reignition of the vacuum switching device frequently appears, and it result in damage of the capacitor bank or the switchgear itself. Ensuring the switchgear against reignition and installing a protective device are two main approaches to avoid the phenomenon. In this paper, a study on overvoltage caused by reignition due to capacitor bank switching with the vacuum switching device and its preventive measures are carried out. The main work which has been done and researches are as follows: 1. The producing mechanism of overvoltage and its influence factor are analyzed. It is pointed out that single-phase reignition is the main reason for damage of the switchgear and two-phase reignition is the main reason for damage of the capacitor bank,so overvoltage of single-phase reignition and two-phase reignition are the emphases of prevention. 2. Analysis of the special working condition of the operating switch for capacitor bank is carried out. It indicates that the vacuum switching device is difficult to realize no-reignition under this operation condition, so it is more practical to adopt protection devices. 3. Analyses of protection effect of RC and MOA and their shortages are carried out. It shows that the two methods can only restrain effectively overvoltage caused by single-phase reignition, and they cannot protect the capacitor bank when reignition of two-phase occurs. 4. The operation principle of G-R damping device is analyzed and discussed emphatically.

本文针对真空开关投切电容器组时因重燃而产生的过电压及其防治措施进行了研究，所开展的主要工作和研究结果如下： 1、对过电压的产生机理及其影响因素进行了分析，指出单相重燃是导致开关设备损坏的主要原因，而两相重燃则是导致电容器组损坏的主要原因，因此单相重燃和两相重燃过电压是防护的重点； 2、对电容器组操作开关的特殊运行条件进行了分析，指出在这种运行条件真空开关难于实现不重燃，因此采用保护装置更具有现实意义； 3、对RC与MOA的保护效果和存在的不足进行了分析，指出这两种方法均只能有效抑制单相重燃过电压，而不能在发生两相重燃时保护电容器组； 4、重点对G-R阻尼装置的工作原理进行了分析和讨论，指出该装置接入后线路中将会出现两种频率的高频振荡，而电容器组上的过电压是由这两种振荡共同决定的； 5、根据对上述两种振荡的分析指出存在一个最佳电阻值使得过电压最低，并提出了电容器组电压和最佳电阻值的近似求解方法； 6、使用电气暂态分析软件MATLAB对G-R装置的保护效果进行了仿真计算，证实该装置确实可以有效抑制重燃时的电容器组过电压； 7、根据仿真与近似计算结果的偏差提出了近似计算的修正方法，经过修正后的过电压计算结果与仿真结果吻合较好； 8、对G-R装置中放电装置G与阻尼电阻R的要求进行了分析，指出采用编织电阻和真空间隙可能是最佳选择。

On the base of practical transformer substation main connection,electriccomponents and system circuit model are first formed in the paper;analyze vacuum arccharacteristic and medium resume are analyzed,then,according to vacuum chamberphysical process of switching AC arc,resume process are divided into three stages:sheathdevelopment,neutral particles diffusion and static characteristic,with that,calculatingmodel of medium resume strength is erected and applied in the computing of vacuumcircuit breaker interrupting transform overvoltage;In the paper,Saber software is used tosimulate a whole switching process;As follows,overvoltage characteristic of vacuumcircuit breaker switching no load and load transformers,kinds of influence factors areanalyzed in detail;At last,vacuum circuit breaker switching capacitance groupovervoltage formative causes and electrode refining for lessening reignition are discuss.

本文针对中低压变电站的实际主接线建立各电气元件及系统的电路模型；在真空电弧的特点及间隙的介质恢复特性上，依据真空断路器灭弧室分断电弧的物理过程，将真空电弧熄灭后的恢复过程分为鞘层发展、中性粒子扩散和静态特性三个阶段，建立了相应的介质恢复强度的计算模型，应用到切除变压器作过电压的计算中；采用Saber仿真软件模拟计算真空断路器切除变压器作过电压；并分别对真空断路器切除空载及负载变压器作过电压的特点与影响作过电压的各种因素做了详细的分析；最后简要分析了真空断路器开断电容器组过电压的形成原因及为减少重燃的电极老炼措施。

On the base of practical transformer substation main connection,electriccomponents and system circuit model are first formed in the paper;analyze vacuum arccharacteristic and medium resume are analyzed,then,according to vacuum chamberphysical process of switching AC arc,resume process are divided into three stages:sheathdevelopment,neutral particles diffusion and static characteristic,with that,calculatingmodel of medium resume strength is erected and applied in the computing of vacuumcircuit breaker interrupting transform overvoltage;In the paper,Saber software is used tosimulate a whole switching process;As follows,overvoltage characteristic of vacuumcircuit breaker switching no load and load transformers,kinds of influence factors areanalyzed in detail;At last,vacuum circuit breaker switching capacitance groupovervoltage formative causes and electrode refining for lessening reignition are discuss.

本文针对中低压变电站的实际主接线建立各电气元件及系统的电路模型；在真空电弧的特点及间隙的介质恢复特性上，依据真空断路器灭弧室分断电弧的物理过程，将真空电弧熄灭后的恢复过程分为鞘层发展、中性粒子扩散和静态特性三个阶段，建立了相应的介质恢复强度的计算模型，应用到切除变压器操作过电压的计算中；采用Saber仿真软件模拟计算真空断路器切除变压器操作过电压；并分别对真空断路器切除空载及负载变压器操作过电压的特点与影响操作过电压的各种因素做了详细的分析；最后简要分析了真空断路器开断电容器组过电压的形成原因及为减少重燃的电极老炼措施。

When compensating devices are switched by vacuum switches, if they are switched on group, the inrush current can be controlled by inserting suitable current-restrained reactance in-series. Since the restriking overvoltage is pertinent to the capacity of compensating devices and the time of restriking and igniting, the overvoltage can be restrained by arresters with asterism connection at the entrance of the capacitors. Although switching capacitance devices will bring up high interception cross overvoltage, the metal-oxide arrester can limit this overvoltage in the system designed in the thesis, and naturally the compensating devices can operate normally.

使用真空开关投切并联无功补偿装置，在分组投入并联电容器时，串联合适的限流电抗，合闸涌流可以得到控制；重燃时的过电压值与并补装置补偿容量，重燃发生时刻和燃弧时间有关，电容器进线端的三星接法避雷器可以抑制其过电压；切并联电抗器时会产生较高的截流过电压，金属氧化物避雷器可以使本文中所建系统的截流过电压得到限制，并联无功补偿装置可以正常切合。

Our main products are: microprocessor-based arc, harmonic elimination and PT counters, high-capacity three-phase modular overvoltage protectors, Intelligent Switchgear control devices (SC-8), current mutual inductance Secondary over-voltage protectors, large-capacity high-speed switching device, de-excitation of synchronous generator rotor Switchgear, composite over-voltage protectors, low-voltage modular overvoltage protectors ( SCB-400), high voltage current-limiting fuse combination switch cabinet, computer integrated protection device and other products.

公司主要产品有：微机型消弧、消谐及PT柜、高能容三相组合式过电压保护器、开关柜智能操控装置（SC-8）、电流互感器二次过电压保护器、大容量高速开关装置、同步发电机转子灭磁开关柜、复合式过电压保护器、低压组合式过电压保护器（SCB-400）、高压限流熔断器组合开关柜、微机综合保护装置等产品。

One thing is to analysis the overvoltage due to the switches of compensating capacitorusing ATP-EMTP program, the other thing is to develop an ovevoltage monitoring system to monitorthe overvoltage at the substation. Based on a real 10kV substation model, the simulation resultsunder various operating modes indicate that the overvoltage of the capacitor is much greater whenthe 10KV bus is light-loaded or the switch is multi-reburning.

论文主要进行两方面的工作，一方面以某一10kV变电站为原型，建立了补偿电容器投切过程过电压的仿真计算模型，利用ATP-EMTP电磁暂态计算程序对多种工况下电容器上的过电压情况进行了仿真计算；另一方面设计组建变电站配网过电压测试分析系统，开展现场实际过电压的监测。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。