The remaining effective life prediction of the relay protection equipment is the key technology of the secondary equipment condition maintenance of the intelligent substation. This paper presents a method for predicting the life of relay protection equipment based on the Markov chain. Based on the Markov chain, the state distribution vector and the state transition matrix are obtained by using the equipment on-line monitoring information and historical operation data, then to predict its remaining effective life based on reliability principle. The results of numerical examples show that the proposed method can effectively predict the future operation state distribution and residual life of the protection device, and the prediction results can provide reference for the operation personnel. At present, this method has been applied in the on-line monitoring system of the intelligent substation secondary equipment, which can help to improve the stability of the intelligent substation.
