绝缘材料TSC测试方法的研究

Thermally stimulated current investigations on the insulation

热刺激电流测试是一种研究电介质电荷存储及陷阱能级等参数的重要手段,已经广泛应用在绝缘材料的性能测试中,然而测试中寄生电导电流的存在对测试结果会产生一定的影响。本文首先探讨了热刺激电流和寄生电导电流的形成机理,然后对变频电机绝缘材料中广泛应用的聚酰亚胺膜进行了寄生电导电流和热刺激电流测试,测试结果表明寄生电导电流随温度的升高而逐渐变化,严重影响了热刺激电流测试的精度。最后,本文提出了一种消除上述干扰的方法,以便从热刺激电流曲线中得到反映电机绝缘材料特性的更精确的参数。

Thermally stimulated current （TSC） is an important trapping parameter in dielectrics. This method is used to obtain method to study the space charge accumulation and the the parameter of dielectrics, but the background current existing in test influences the results. In this paper, the mechanism of TSC and parasitic conduction current is discussed. The tests of parasitic conduction current and TSC to polyimide （PI） used in inverter-fed motor have been done. It is shown by the test results that the parasitic conduction current changes with the temperature rising, and the precision of TSC is affected seriously. To eliminate the interference mentioned above, a correction approach for TSC test is presented. The material parameter could be obtained more precisely from the corrected TSC curve.