有關(guān)絕緣材料中英對照

1、為了使得導(dǎo)線相互隔離并且不接觸到其他的物體，必須采取絕緣措施。在理想的條件下，絕緣應(yīng)做到完全不導(dǎo)電，那樣電流才能會完全束縛在計劃的導(dǎo)體內(nèi)。但事實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。在許多情況下，由于絕緣材料的導(dǎo)電性造成的漏電流很小，以致于可以忽略不計。在一些情況下，采用非常敏感的儀器測量的漏電流可以用來確定某種絕緣措施是否合適。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烈地導(dǎo)致其迅

2、速損壞。在電力系統(tǒng)中有相當(dāng)比例的設(shè)備損壞是由于絕緣故障引起的。絕緣設(shè)計人員面臨的問題包括選擇合適的材料、合適的形狀和尺寸，以及控制破壞性因素等。絕緣材料有許多絕緣材料應(yīng)用于電力系統(tǒng)中，絕緣材料的選擇取決于具體應(yīng)用的需要和費用。在居民小區(qū)，分支線和電線中的導(dǎo)體可以采用橡膠或各種塑料材料絕緣。這些材料可以承受必要的彎曲，但其電器應(yīng)力較低。高壓電纜適用于較大的電氣應(yīng)力場合，在某種情況下，幾百千伏的電壓只采用幾厘米厚的絕緣處理。這些絕緣材料必做成長形的，并且足夠柔軟，以便于將其穿進小口徑的管道。絕緣材料可以是油浸紙質(zhì)、浸漆麻紗或合成材料。發(fā)電機和電動機的繞組可以采用絕緣帶絕緣。一些絕緣帶是通過用膠將云

3、母片粘在一起而制成的，另一些是采用絕緣漆浸的玻璃纖維制成的。這些絕緣方式必須能夠承受很高的溫度、很強的機械力和振動。電力變壓器的繞組的絕緣通常采用油浸紙帶和壓制紙板。紙在油的浸泡下，其絕緣強度大大增加，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。變壓器絕緣要能經(jīng)受高的電氣應(yīng)力和強的機械應(yīng)力。在變壓器的設(shè)計中，導(dǎo)電的金屬不見的形狀和布置必須特別考慮。架空線是通過瓷絕緣子絕緣的。在支撐件之間是采用空氣絕緣的。選用陶瓷材料是用它在暴露于環(huán)境中時，具有抗變質(zhì)能力，并且具有高的介電強度而且在雨中能夠得到清洗。insulation is required to keep ele

4、ctrical conductors separated from each other and from other nearby objects.ideally，insulation should be totally no conducting，for then currents are totally restricted to the intended conductors.however，insulation does conduct some current and so must be regarded as a material of very high resistivel

5、y.in many applications，the current flow due to conduction through the insulation is so small that it may be entirely neglected.in some instances the conduction currents，measured by very sensitive instruments，serve as a test to determine the suitability of the insulation for use in service.although i

6、nsulating materials are very stable under ordinary circumstances，they may change radically in characterstics under extreme conditions of voltage stress or temperature or under the action of certain chemicals.such changer may，in local regions，result in the insulating material becoming highly conducti

7、ve.unwanted current flow brings about intense heating and the rapid destruction of the insulating material.these insulation failures account for a high percentage of the equipment troubles on electric power systems.the selection of proper materials，the choice of proper shapes and dimensons and the c

8、ontrol of destructive agencies are some of the problems of the insulation-system designer.insulating materials many different materials are used as insulation on electric-power system.the choice of material is dictated by the requirements of the particular application and by cost.in residences，the c

9、onductors used in branch circuits and in the cords to appliances may be insulated with rubber or plastics of several different kinds.such materials can withstand necessary bending，are relatively low electrical stress.high-voltage cables are subjected to extreme voltage stress：in some several hundred

10、 kilovolts are impressed across a few centimeters of insulation.they must be manufactured in long section，and must be sufficiently flexible as to permit pulling into ducts of small cross section.the insulation may be oil-impregnated paper，varnished cambric，or synthetic materials such as polyethylene

11、.the coils of generators and motors may be insulated with tapes of various kinds.some of these are made of thin sheets of mica held together by a binder，and others are of fiber glass inpreating with insulating varnish.this insulation must be capable of withstanding quite high operating temperatures，

12、extreme mechanical forces，and vibration.the insulation on power-transformer windings is commonly paper tape and pressboard operated under oil saturates the paper，greatly increasing its insulation strength，and by circulating through ducts，serves as an agent for carrying a way the heat generated due to losses and core losses in the transformer.the shape and arrangement of conducting metal parts is of particular concern in transformer design.overhead lines are supported on porcelain insulators.betw