氧化锌避雷器是七十年代发展起来的一种新型避雷器，它主要由氧化锌压敏电阻构成。每一块压敏电阻从制成时就有它的一定开关电压（叫压敏电压），在正常的工作电压下（即小于压敏电压）压敏电阻值很大，相当于绝缘状态，但在冲击电压作用下（大于压敏电压），压敏电阻呈低值被击穿，相当于短路状态。然而压敏电阻被击后，是可以恢复绝缘状态的；当高于压敏电压的电压撤销后，它又恢复了高阻状态。因此，如在电力线上安装氧化锌避雷器后，当雷击时，雷电波的高电压使压敏电阻击穿，雷电流通过压敏电阻流入大地，可以将电源线上的电压控制在安全范围内，从而保护了电气设备的安全。 HY5WX-51/134氧化锌避雷器多少钱
特性
氧化锌避雷器七大特性：
通流能力
这主要体现在避雷器具有吸收各种雷电过电压、工频暂态过电压、操作过电压的能力。
保护特性
氧化锌避雷器是用来保护电力系统中各种电器设备免受过电压损坏的电器产品，具有良好保护性能。因为氧化锌阀片的非线性伏安特性十分优良，使得在正常工作电压下仅有几百微安的电流通过，便于设计成无间隙结构，使其具备保护性能好、重量轻、尺寸小的特征。当过电压侵入时，流过阀片的电流迅速增大，同时限制了过电压的幅值，释放了过电压的能量，此后氧化锌阀片又恢复高阻状态，使电力系统正常工作。HY5WX-51/134氧化锌避雷器多少钱
密封性能
避雷器元件采用老化性能好、气密性好的优质复合外套，采用控制密封圈压缩量和增涂密封胶等措施，陶瓷外套作为密封材料，确保密封可靠，使避雷器的性能稳定。
机械性能
主要考虑以下三方面因素：
A承受的地震力；
B作用于避雷器上的大风压力；
C避雷器的顶端承受导线的大允许拉力。
解污秽性能
无间隙氧化锌避雷器具有较高的耐污秽性能。
国家标准规定的爬电比距等级为：
II级 中等污秽地区：爬电比距20mm/kv
III级 重污秽地区：爬电比距25mm/kv
IV级 特重污秽地区：爬电比距31mm/kv
高运行可靠性
*运行的可靠性取决于产品的质量，及对产品的选型是否合理。影响它的产品质量主要有以下三方面：
A 避雷器整体结构的合理性；
B 氧化锌阀片的伏安特性及耐老化特性；
C 避雷器的密封性能。
工频耐受能力
由于电力系统中如单相接地、长线电容效应以及甩负荷等各种原因，会引起工频电压的升高或产生幅值较高的暂态过电压，避雷器具有在一定时间内承受一定工频电压升高能力。
Zinc oxide arrester is a new type of arrester developed in the 1970s. It is mainly composed of zinc oxide varistor. Each varistor has its own switching voltage (called varistor voltage) from the time it is made. Under normal working voltage (i.e. less than the varistor voltage), the varistor value is very large, which corresponds to the insulation state, but under impulse voltage (greater than the varistor voltage), the varistor is broken down at a low value, which corresponds to the short circuit state. However, when the varistor is struck, the insulation state can be restored; when the voltage higher than the varistor voltage is withdrawn, the high resistance state can be restored. Therefore, if the zinc oxide arrester is installed on the power line, when lightning strikes, the high voltage of the lightning wave breaks down the varistor, and the lightning current flows into the earth through the varistor, the voltage on the power line can be controlled in a safe range, thus protecting the safety of electrical equipment.
Characteristic
Seven characteristics of zinc oxide arrester:
Flow capacity
This is mainly reflected in the arrester has the ability to absorb all kinds of lightning overvoltage, power frequency transient overvoltage, operating overvoltage.
Protection characteristics
Zinc oxide arrester is an electrical product used to protect all kinds of electrical equipment from overvoltage damage in power system. It has good protection performance. Because the non-linear volt-ampere characteristic of zinc oxide valve sheet is very good, only a few hundred microamperes of current pass through under normal working voltage. It is easy to design a gapless structure, which has the characteristics of good protection performance, light weight and small size. When the overvoltage intrudes, the current flowing through the valve plate increases rapidly, at the same time, the amplitude of the overvoltage is limited, and the energy of the overvoltage is released. Then the zinc oxide valve plate resumes its high resistance state and makes the power system work normally.
Sealing performance
Surge arrester components adopt high-quality composite coat with good aging performance and air tightness. Ceramic coat is used as sealing material to ensure reliable sealing and stable performance of surge arrester.
Mechanical properties
The following three factors are considered:
A. The seismic force.
B. Maximum wind pressure acting on the arrester;
The top of the C arrester bears the maximum allowable tension of the conductor.
Decontamination performance
Gapless zinc oxide arrester has high pollution resistance.
The creepage ratio distance classified in the national standard is as follows:
Class II medium polluted area: creepage ratio 20 mm/kv
Class III heavily polluted area: creepage ratio 25 mm/kv
Class IV Extra Heavy Pollution Area: Creep Ratio Distance 31mm/kv
High operational reliability
The reliability of long-term operation depends on the quality of products and the rationality of product selection. There are three main aspects that affect the quality of its products:
Rationality of the overall structure of A arrester;
Volt-ampere characteristics and aging resistance of B zinc oxide valve sheet;
Sealing performance of C arrester.
Power Frequency Tolerance
Due to various reasons in power system, such as single-phase grounding, long-line capacitance effect and load rejection, the power frequency voltage will rise or the transient overvoltage with high amplitude will occur. The arrester has the ability to withstand a certain power frequency voltage rise in a certain period of time.
