氧化鋅壓敏電阻器的工頻過電壓（TOV）特性

摘要：本文就氧化鋅壓敏電阻器的工頻過電壓特性（以下稱TOV特性）的重要性、正確表征和影響因素展開討論。提出TOV特性應以TOV幅值及對應的耐受時間來表述，稱為TOV耐受時間特性，作為給SPD應用的氧化鋅壓敏電阻器的設計應用資料，則應提供兩個數據，一是TOV耐受時間特性，二是暫態過電壓施加時溫度隨時間變化數據。氧化鋅壓敏電阻器的TOV耐受時間特性，直接與耐受TOV能量的能力以及TOV工作區（1mA～10A）V-I特性曲線相關，制約耐受TOV能量的能力的因素，是配方與工藝引起的晶相差異和結構的均勻性，以及熱穩定性。TOV工作區（1mA~10A）V-I特性曲線，除了受配方與工藝影響外，還受工作歷史的影響。電阻體均勻性好的TOV特性好，而TOV工作區（1mA～10A）V-I特性曲線非線性差或電壓正溫度數引起加載TOV時電流變小，可以提高TOV耐受時間。 敘詞：氧化鋅壓敏電阻器 工頻過電壓(TOV) TOV耐受時間特性 表征 影響因素 Abstract：The article focuses on the importance, proper representation and influential factors of TOV for ZnO varistors. It states that TOV should 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(1mA10A). 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 zone1mA10A 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 zone1mA10A V-I curve. Keyword：ZnO varistor, TOV, TOV Feature of tolerance time, Representation, Influential factors