The problems in the recursive state estimation for digitalized power grids subjected to cyber attacks under Round-Robin（RR） protocol are investigated. Data transmitted between the state estimators and the sensors of a digitalized power grid are vulnerable to the interception of adversaries. As a result，a recursive state estimator for the digitized power grid is proposed which can guarantee the upper bound of error covariance while reducing the impact of cyber assaults on the accuracy of state estimation. A cyber-attack model that comprises denial of service（DoS）and deception attacks is constructed. Moreover，the RR protocol is employed to handle network congestion problems，and the algebraic Riccati equations and stochastic analysis are employed to deduce the upper bound of error covariance. Finally，a simulation example is given to show that the proposed design of recursive state estimators is valid.
