基于Havriliak-Negami介电模型的油纸绝缘老化参数提取

电力变压器是电能传输中最重要的设备之一,检测变压器老化状态具有重要意义。为了对变压器内油纸绝缘的老化状态进行有效评估,文中通过频域介电谱法(FDS)研究了不同老化程度下油纸绝缘的介电特性,并通过引入Havriliak-Negami(H-N)模型建立了特征参量与老化时间之间的关系,最后将此方法应用于现场变压器的测试,进行了验证。结果表明:随着老化程度的加深,FDS曲线在高、低频段变化不明显,中频段显著增大,总体曲线呈“枣核”状;依据H-N模型提取的特征参量与老化程度具有良好的对应关系;对现场变压器的应用验证了此方法对于评估变压器老化状态的可行性。

Extraction of oil-paper insulation aging parameters based on Havriliak-Negami dielectric model

Power transformer is one of the most important equipments in power transmission, and it is of great significance to detect the aging state of transformers. In order to effectively evaluate the aging condition of oil paper insulation in transformers, the dielectric properties of oil-paper insulation under different aging degrees are studied by frequency domain spectroscopy (FDS). Besides, the relationship between the characteristic parameters and aging time is established by Havriliak-Negami (H-N) model. Then, this method is applied to the field transformer test. The results show that with the deepening of aging degree, the FDS curve increases significantly in the middle frequency band, but does not change significantly in the high and low frequency bands. The overall curve is in the shape of ''jujube nucleus''. According to the H-N model, the characteristic parameters have a good correspondence with the aging degree. This method that evaluates the aging condition of transformers is verified by the application of the field transformer.