摘要
本文就氧化锌压敏电阻器的工频过电压特性(以下称TOV特性)的重要性、正确表征和影响因素展开讨论。提出TOV特性应以TOV幅值及对应的耐受时间来表述,称为TOV耐受时间特性,作为给SPD应用的氧化锌压敏电阻器的设计应用资料,则应提供两个数据,一是TOV耐受时间特性,二是暂态过电压施加时温度随时间变化数据。氧化锌压敏电阻器的TOV耐受时间特性,直接与耐受TOV能量的能力以及TOV工作区(1mA～10A)V-I特性曲线相关,制约耐受TOV能量的能力的因素,是配方与工艺引起的晶相差异和结构的均匀性,以及热稳定性。TOV工作区(1mA～10A)V-I特性曲线,除了受配方与工艺影响外,还受工作历史的影响。电阻体均匀性好的TOV特性好,而TOV工作区(1mA～10A)V-I特性曲线非线性差或电压正温度数引起加载TOV时电流变小,可以提高TOV耐受时间。
The article focuses on the importance, proper representation and influential factors of TOV for ZnO varistors. It states that TOV stlould be represented as TOV maximum value and relevant tolerance time, thus being referred to as TOV feature of tolerence time. For applicable data to design ZnO varistors for SPD application, two data should be provided： one is TOV tolerance time, the other is data related to temperature change in accordance with time after implementing transient overvoltage. The TOV tolerance time feature of ZnO varistors is directly related to TOV caPacity of energy and TOV work zone V-I curve（lmA - 10A）. The factor that restricts TOV capacity of energy is thermostability and the crystal phase difference and structural uniformity which results from formula and technology. Besides the.influence of formula and technology, TOV work zone（1mA - 10A） V-I curve is also affected by work process. The better the uniformity of the resistors, the better performance TOV will be. TOV tolerance time can be improved when the current turns smaller resulting from the loading of TOV because of the nonlinear difference or voltage positive temperature of TOV work zone （ 1mA- 10A） V-I curve.
出处
《电源世界》
2012年第1期58-61,64,共5页
The World of Power Supply
