短路冲击下变压器绕组状态在线诊断

摘要

In order to keep safe operation of a power transformer, it is important to monitor the state of the transformer winding on real-time basis. The winding' s state is reflected by its vibration signal measured with accelerometers located on the transformer's tank. In a short-circuit shock test for one large power transformer, the state of every phase of the winding was initially detected with the change of the transformer's vibration intensity. The method of time-frequency analysis was then used to analyze the vibration response signal in order to confirm the winding's state.Compared with the traditional method based on short-circuit reactance measurement, the time-frequency analysis could exactly reveal the fault characteristics of the winding.%在线实时检测变压器绕组状态,对保障变压器正常运行尤为重要.绕组的振动信号能反映出绕组的状态,而这些信号能通过布置在变压器箱体上的加速度传感器测量到.通过对某大型变压器短路冲击实验的在线实时检测,利用振动烈度和基于时频分析的方法对变压器绕组的振动信号进行分析.研究表明,与常规电抗法检测相比较,用时频分析方法能更明确反映出变压器绕组的故障特征.