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电压击穿试验仪的常规反映和允许条件之内的影响因素做出以下解释

时间:2013-04-28      阅读:1013

  北广精仪公司对于电压击穿试验仪的常规反映和允许条件之内的影响因素做出以下解释

 
 
电压击穿测试的影响因素:
 
电压波形及电压作用时间影响。
 
 媒质电性能影响:高压击穿试验往往把样品放在一定媒质(如变压器油)中.其目的为缩小试样尺寸防止飞弧。但媒质本身的电性能对属于电击穿为主的材料有明显影响,而以热击穿为主的材料影响极小.故标准中对要求油的击穿电压 VB>=25kv/2.5m
 
        试样厚度对介电强度的影响:试样厚度与介电强度不成线性关系,通常同种材料在不同厚度下测得的介电强度是不同的,较厚的试样测得的介电强度略低些。 湿度影响:因水分浸入材料而导致其电阻降低,必然降低击穿电压值。
 
        电极倒角的影响:电极边缘处电场强度远远高于内部,但边缘效应极难消除。为避免电极边缘成一直角,需采用一定倒角r 。国家标准中规定r=2.50mm。     
 
 材料在电场作用下,初始时单位时间内材料内部产生的热量大于介质散发出去的热量,进而介质温度升高,温度的升高是一个由快转慢的,若升压速度较慢后发生材料击穿热击穿的成分较大。
 
作用时间的影响多因热量积累而使击穿电压值随电压作用时间增加而下降,处于热击穿形式的试样,基本上随升压速度的提高击穿强度也增大。因此,一般规定试样击穿电压低于20kv时升压速度为1.0kv/s;大于或等于20kv时升压速度为2.0kv/s。 温度的影响:温度的增加普遍介电强度降低。
 
 
:北京北广精仪仪器设备有限公司
 
 

This precision instrument company normal reactions to the breakdown voltage test apparatus and allow the influence factors of conditions within the following interpretation

 

 

The influence factors of breakdown voltage test:

 

Voltage waveform and time influence the voltage effect.

 

Breakdown test medium electrical effects: high pressure tend to put the samples in a certain medium (such as transformer oil). Its purpose is to narrow the sample size to prevent flashover. But medium itself performance to belong to electric breakdown had significant effect on the material, but little effect mainly thermal breakdown of the materials. So the standard require oil breakdown voltage in VB > = 25 kv / 2.5 m

 

Specimen thickness effect on the dielectric strength, thickness and dielectric strength is not a linear relationship, usually the same material under different thickness measured dielectric strength is different, the thicker specimen measured slightly lower dielectric strength. Humidity impact: the resistance caused by the moisture in material to reduce, will reduce the breakdown voltage value.

 

Electrode chamfering: the influence of electric field intensity is much higher than the internal electrode edge and edge effect but very difficult to eliminate. In order to avoid the electrode edge into a right Angle, it is necessary to adopt certain chamfering r. Specified in the national standard r = 2.50 mm.

 

Materials under the effect of electric field, the initial material per unit time when internal heat is greater than the heat coming out of the medium, and medium temperature, temperature increase is a from fast to slow, slower if booster material breakdown happened at last larger thermal breakdown of the components.

 

More action time of impact due to heat accumulation and the breakdown voltage value decline with the increase of voltage effect time, thermal breakdown in the form of samples, basically breakdown strength also increase. The increase of pressure rise speed Therefore, general provisions sample breakdown voltage is lower than 20 kv booster when speed is 1.0 kv/s; Greater than or equal to 20 kv booster when speed is 2.0 kv/s. The effect of temperature: the temperature increase general dielectric strength reduced.

 

 

 

 

 

 

 

 

 

Tech support: Beijing all fine instrument equipment co., LTD

上一篇: 电压击穿试验仪,体积电阻率表面电阻率测试仪 电场作用下,丧失能力的现象 下一篇: 电压击穿试验仪介电击穿强度试验仪检测绝缘材料丧失绝缘能力检测
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