工频范围内高压发电机定子线圈绝缘内部气隙群放电行为的研究

Study on Discharge Behavior of Air-gap inside Stator Coil Insulation for High Voltage Generator in Power Frequency

为了分析在工频电源频率范围内高压电机定子线圈主绝缘内部存在气隙群放电(包括无气隙群放电、完全型气隙群放电和非完全型气隙群放电)时对定子线圈绝缘的介质损耗因数(tanδ)与对地电容(C)的影响,测试并分析了主绝缘材料的相对介电常数和介质损耗因数的工频频谱特性、线圈介质损耗因数和电容随电压的变化规律。结果表明:在线圈绝缘内部无气隙群放电的情况下,电源频率与施加电压对线圈绝缘介质损耗因数和电容基本无影响;在线圈绝缘内部存在气隙群放电的情况下,电源频率与施加电压对线圈介质损耗因数和电容的影响很大。

In order to analyze the influence of air-gap discharge inside main insulation of stator coil for high voltage generator in power frequency, including the no air-gap discharge, complete air-gap discharge, and incomplete air-gap discharge, on the dielectric loss factor （tanδ） and capacitance （C） of the stator coil insualtion, we tested and analyzed the relative permittivity and tanδ of the main insulation materials in power frequency and the change of tanδ and C of the stator coil with voltage. The results show that when there is no air-gap discharge inside the coil insulation, the voltage and frequency have no influence on the tanδ and C of the coil insulation. When there is air-gap discharge inside the coil insulation, the voltage and frequency have great influence on the tanδ and C of the coil insulation.