Countermeasures on abnormal data in the signal acquisition system of digital substations

Abnormal data would appear in the signal acquisition system of a digital substation as a result of the disturbance from external environment. A data processing algorithm is proposed in this paper in order to meet the challenge of the abnormal data. It is proved in this paper that any three consecutive sampling values should satisfy a certain constraint condition in the ideal situation of the power system. The constraint condition is used to judge whether a real sampling value is abnormal. A complete algorithm is presented including three main steps. Simulation work verifies the effectiveness of the algorithm.