Modeling and Analysis of EVs Aggregation Based on Extended Markov Chain

The precise aggregation method is of great significance for Electric vehicle population (EVP) to participate in grid ancillary services as a flexible resource. In this paper, considering the difference of charge-discharge characteristics and charging power of EV batteries, the Markov chain model of three states is extended to five states, and the one-step transfer probability is calculated according to the relationship between the charging power and the state of charge when calculating the Markov chain state transition matrix, which solves the problem of the explosion of the Monte Carlo method with the increasing number of individuals and parameters. Simulation examples are used to verify that the aggregation model based on extended Markov chain has good accuracy.