保定电气厂家价格-交流无间隙金属氧化物避雷器

金属氧化物避雷器的结构特性

The structural characteristics of metal oxide arresters

金属氧化物避雷器的基本结构是阀片[ 5 2 ]，阀片用氧化锌（ZnO）为主要材料，掺以少量其他金属氧化物添加剂经高温焙烧而成，具有良好的非线性压敏电阻特性，因此又叫压敏避雷器。

The basic structure of metal oxide arrester is the valve [52], Zinc Oxide valve (ZnO) as the main material, mixed with a small amount of other metal oxide additives by high temperature roasting, has good characteristics of nonlinear varistor, so called varistor arrester.

这种烧结体的基本结构是高电导的氧化锌晶粒，电阻率为1 Ω⋅ cm。边缘由高电阻性的（主要是金属氧化物附加物）粒界层包围，电阻率在低电场强度下约为1010 ~ 1014Ω⋅cm。在较高的电压作用下，金属氧化物附加物的粒界层中的价电子被拉出，或者由于碰撞电离产生电子崩而使载流子大量增加[ 5 4 ]。当电场强度达到104 ~ 105V / cm时，其电阻率即降到1 Ω⋅ cm；当外加作用电压降低时，由于复合使载流子减少，电阻又变大，因此具有良好的非线性。且它的非线性伏安特性在正、反极性是对称的。

The basic structure of the sintered body is Zinc Oxide grain high conductivity, resistivity of 1 ohm cm. The edge from the high resistive (mainly metal oxide additives) grain boundary layer surrounded by resistivity under low field strength is about 1010 ~ 1014 cm. When the applied voltage is high, the valence electron grain boundary layer of metal oxide additions in being pulled out, or due to impact ionization avalanche caused a large increase in carrier [54]. When the electric field reaches 104 ~ 105V / cm, the resistivity is reduced to 1 cm; when the applied voltage is decreased, the composite carrier reduced resistance and larger, so it has good nonlinear. And its nonlinear volt ampere characteristic is symmetrical in positive and reverse polarity.

金属氧化物阀片在正常工作电压下， 通过的阻性电流很小， 一般约为10 ~ 15μA，接近绝缘状态。作用于阀片上的电压升高时，电流加大。把通过阀片的阻性电流为1mA时，作用于避雷器上的电压mA U1 为起始动作电压。由于氧化锌阀片有良好的非线性特性，在通过10kA冲击电流时残压与mA U1 的比值一般不大于1.9，压比越小，其保护性能越好。mA U1 的值约为最大允许工作电压峰值的1.05～1.15倍。

Metal oxide valve at normal operating voltage through the resistance of the current is very small, generally about 10 ~ 15 A, close to the insulation state. When the voltage on the valve plate rises, the current increases. When the resistance current through the valve plate is 1mA, the voltage mA U1 acting on the arrester is the starting action voltage. Since the Zinc Oxide valve has good nonlinear characteristics, the ratio of residual pressure to mA U1 is generally no more than 1.9 when the impact current is passed through the 10kA. The smaller the pressure ratio is, the better the protection performance is. The value of the mA U1 is about 1.05 to 1.15 times the maximum allowable operating voltage peak.