变电所防雷保护几个问题浅见

SOME ASPECTS RELATED TO LIGHTNING PROTECTION OF SUBSTATIONS

提出了对中国现行变电所防雷保护几个主要问题的看法 :1由于东西方国家在防护概念上的差异 ,采用的保护不尽相同。2变电所防雷保护是一个系统工程 ,由三个子系统即三道防线构成一个完整的变电所防雷保护系统。这三道防线之间关系密切 ,互相影响 ,各负其责 ,缺一不可 ,不存在谁替代谁的问题 ,把三道防线弧立地割裂开来是错误的。3电力变压器不论哪侧绕组损坏 ,后果都是一样的 ,因此绕组各侧设定的耐雷可靠性应一致。选用的无间隙金属氧化物避雷器 (WGMOA)的 In 等级应相同。4选用沿架空输电线路导线上侵入变电所的雷电波陡度和幅值不应“一刀切”,应根据被保护物 (如电力变压器 )的技术经济重要性的不同区别选取 ,以获最佳经济效益。

The opinion related to the current practice of lightning protection of substations in China is presented: (1) The practices of lightning protection of substations in East and West countries are different in some aspects because of the difference of their protection concepts; (2) Lightning protection of substations is a systematic project, consisting of three sub-systems, i.e., three defense lines. They form an integrity of protective system of substations against lightning. Close relationship exists among these defense lines. These lines each having its own function, influence each other, and cannot work properly without others' presence. Therefore, each of them cannot be replaced by other(s). It is not correct to isolate and separate these lines from each other; (3) The consequence of damage of transformer windings, no matter on which side, is equal. Therefore, the reliability of lightning protection shall be in conformity for all windings. The surge arresters protecting the windings shall be selected in equal nominal current class; (4) The steepness and amplitude of the surge impinging from overhead lines shall be selected depending on importance of the protected objects, rather than “all cut”, to obtain optimal economic benefit.