【正文】
架空線是通過瓷絕緣子絕緣的 。 絕緣材料可以是油浸紙質(zhì)、浸漆麻紗或合成材料 。 盡管在正常情形下絕緣材料的性能會很穩(wěn)定 , 但在極端情況下 , 比如電壓過高、高溫或在某種化學(xué)物質(zhì)的作用下 , 絕緣材料的性能會遭到完全的破壞 , 絕緣材料的性能的改變會導(dǎo)致其成為良導(dǎo)體 , 由此而造成的不應(yīng)有的電流會使得絕緣材料被強(qiáng)烈地導(dǎo)致其迅速損壞 。但事實(shí)上即使采用絕緣措施也會有少許漏電流 , 因此絕緣材料應(yīng)當(dāng)當(dāng)作具有高電阻率的材料看待 。這些材料可以承受必要的彎曲 , 但其電器應(yīng)力較低 。 紙?jiān)谟偷慕菹?,其絕緣強(qiáng)度大大增加 , 而且令油在管道中循環(huán) , 還可以帶走變壓器中的歐姆損耗和鐵芯損耗引起的熱量 。 Insulation is required to keep electrical conductors separated from each other and from other nearby , insulation should be totally no conducting, for then currents are totally restricted to the intended , insulation does conduct some current and so must be regarded as a material of very high many applications, the current flow due to conduction through the insulation is so small that it may be entirely some instances the conduction currents,measured by very