基于扫频电流法的电力变压器绕组变形诊断

Method of power transformer winding deformation diagnosis based on sweep frequency current method

目前对变压器绕组检测的方法大都是对绕组的变形类型和故障程度进行诊断,对绕组故障位置的定位效果不够理想。为此,文中提出一种基于扫频电流法对变压器绕组变形进行诊断的方法。该方法在绕组的首端注入600 kHz~1 MHz频率范围的扫频信号源,对绕组运行时测得的首端和末端扫频电流信号数据进行处理;再利用计算得到的CDC值与电流偏移量对变压器绕组故障进行诊断。最后通过建立变压器的绕组等值仿真电路检验方法的可行性。结果表明,文中方法不仅可以对绕组是否发生故障进行检测,还可以对绕组发生故障的类型、程度、变形进行判断。该方法对变压器绕组变形检测技术的发展具有重要意义。

At present,most of the proposed detection methods for transformer windings are to diagnose the deformation type and fault degree of the windings,and the positioning effect of the winding fault location is not ideal. On this basis,a method of transformer winding deformation diagnosis based on sweep frequency current method is proposed. In this method,the sweep frequency signal source in the frequency range of 600 kHz~1 MHz is injected into the head end of the winding to process the head end and end sweep current signal data measured when the winding is running,and then the calculated CDC value and current offset are used to diagnose the transformer winding fault. The feasibility of the method is tested by establishing the equivalent simulation circuit of the transformer winding. The results show that the proposed method can not only detect whether the winding is faulty,but also judge the type,degree and deformation of the winding fault. This method is also of great significance to the development of transformer winding deformation detection technology.