大直径球-板结构改进间隙系数及其在特高压直流换流站空气间隙净距计算中的应用  

Improved Gap Factor of Large Sphere-plane and Its Application in Calculating Air Gap Clearance in UHVDC Converter Station

作　　者：陈赦[1] 庄池杰[1] 曾嵘[1] 丁玉剑[2] 宿志一[2] 廖蔚明[2] 

机构地区：[1]清华大学电机工程与应用电子技术系,北京100084 [2]中国电力科学研究院,北京100192

出　　处：《高电压技术》2013年第6期1360-1366,共7页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(2011CB209403)~~

摘　　要：换流站阀厅空气间隙净距的选择直接关系到特高压直流工程的安全稳定运行和工程造价。以往工程主要采用IEC提供的方法计算空气间隙净距,方法中关于间隙系数K的考虑相对简单。为此,基于阀厅内典型电极结构50%放电电压U50的试验数据,提出了新的典型间隙系数值,用于阀厅空气间隙净距的选取计算。相对于以往方法,新的间隙系数包含了间隙尺寸和电极结构的影响。在间隙距离为4～9m的情况下,对于相同球直径,随着间隙距离L的增大,K值逐渐减小;对于相同间隙距离,随着球直径D的减小,K值逐渐减小。临近一面墙使K减小1.06倍,因此需要更大的空气间隙净距。该改进方法对优化阀厅结构、减小阀厅尺寸作用明显。以±800kV工程为例的计算结果证明,部分阀厅典型空气间隙净距可缩小尺寸0.6～0.9m,优化比例达8%～34%。The choice of air gap clearance in valve hall has great impact on the costs and safe operation of UHVI）U projects. In former designs, the air gap clearance was normally calculated using the method in IEC standards, which only simply took the gap factor K into consideration. Thus, on the basis of U^0 experiments of typical electrodes, we proposed a novel gap factor for calculating air gap clearance, in which the influence of electrode dimension, gap distance, and the proximity of wall were taken into consideration. The results reveal that, with the increase of gap distance L{within 4--9 m）, the gap factor decreases. The gap factor also decreases as the diameter D of a sphere electrode decreases. At the proximity of a wall, the gap factor is reduced by 0.06 times, which requires a larger air gap clearance. The modified air gap clearance calculation method is of great significance to structure optimizing and size reducing of valve hall. Taking a ±800 kV project for example, by the modified method, the air gap clearance of some gaps can be reduced by 0.6±0.9 m, i.e. 8%-34% of the original values. Key words： UHVDC; converter station; valve hall; air gap clearance; parameter g; gap factor

关 键 词：特高压直流 换流站 阀厅 空气间隙净距 g参数法 间隙系数 

分 类 号：TM721.1[电气工程—电力系统及自动化]