基于Prony分析的励磁涌流识别方法

目前电力变压器差动保护的主要问题仍是如何准确识别出励磁涌流。励磁涌流中包含大量谐波分量,各谐波分量除幅值信息之外还包括衰减信息,如何有效地利用这些信息来提高保护动作的正确率是一个值得关注的问题。利用Prony分析方法可以直接计算出各分量的频率、幅值、衰减等信息,本文利用Matlab语言实现Prony分析方法,获得了涌流中谐波衰减特征,利用二次谐波衰减因数和基波衰减因数之比构成识别涌流的新方法,通过对动模试验数据的分析计算验证了本方法的有效性。

An inrush current identification method based on Prony analysis

Now the main problem in differential protection of transformer is how to identify inrush current.Inrush current contains a mass of harmonic components,which have the information of attenuation besides of magnitude.How to use these information to improve the performance of transformer protection is worthy studying.The information of frequency,magnitude and attenuation can be calculated directly with Prony analysis method.In the paper,Prony method is realized with Matlab program and the attenuation characteristic of all harmonic components are obtained.A new method to recognize inrush is put forward based on the ratio between the attenuation of the second harmonic component and the primary component.The availability of the method is proved by data analyzing from dynamic analog test.