The working voltage of the high-voltage high-power electronic devices is the positive periodic square waveform (PPSW) voltage, which is much different from the conventional AC or DC voltage. For the composite insulation structure of devices, it is important to analyse the transient electric field under the PPSW voltage. However, the existing investigations are often conducted under the electrostatic field due to the high frequency of the PPSW voltage. Thus, the transient characteristics of the electric field are missed. To obtain some qualitative conclusions, this paper focusses on the theoretical analysis of the transient characteristics of electric field for the composite insulation structure under the PPSW voltage. First, the formula of the electric field intensity and the interfacial charge density are derived analytically. Second, the influence of the cycle and the duty cycle on the transient characteristics are investigated. Third, the maximum of the electric field intensity and the interfacial charge density in the positive square waveform steady-state are discussed in detail. Besides, the engineering calculation methods for obtaining these maximum values are also suggested. Lastly, an actual model is employed to testify the validity of the analytical analysis. This work is significant for the numerical calculation of the transient electric field of composite insulation structure under the PPSW voltage in engineering.

中文翻译：

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正周期方波电压下复合绝缘结构的瞬态电场分析与应用

高压大功率电子器件的工作电压为正周期方波（PPSW）电压，与传统的交流或直流电压有很大不同。对于器件的复合绝缘结构，分析PPSW电压下的瞬态电场很重要。然而，由于 PPSW 电压的高频，现有的研究通常在静电场下进行。因此，错过了电场的瞬态特性。为了得到一些定性的结论，本文着重对PPSW电压下复合绝缘结构的电场暂态特性进行理论分析。首先，解析推导出电场强度和界面电荷密度的公式。第二，研究了周期和占空比对瞬态特性的影响。第三，详细讨论了正方波稳态下电场强度的最大值和界面电荷密度。此外，还提出了获得这些最大值的工程计算方法。最后，采用实际模型来验证分析分析的有效性。该工作对工程中PPSW电压下复合绝缘结构瞬态电场的数值计算具有重要意义。还提出了获得这些最大值的工程计算方法。最后，采用实际模型来验证分析分析的有效性。该工作对工程中PPSW电压下复合绝缘结构瞬态电场的数值计算具有重要意义。还提出了获得这些最大值的工程计算方法。最后，采用实际模型来验证分析分析的有效性。该工作对工程中PPSW电压下复合绝缘结构瞬态电场的数值计算具有重要意义。