When the micro-grids and renewable energy are generally integrated into the urban power grid

the computational burden of state estimator will be much increased and the speed will be too slow. This paper propose a novel distributed state estimation algorithm based on PMU measurements and the characteristics of urban power grid. Through the algorithm

the power grid is divided into different levels and multi-areas. At the subsystem level

the local estimation can be executed in a parallel way

and the linear estimation can be carried out at the coordinated level. Finally

the novel algorithm can sharply improve the computational efficiency. Case studies in the IEEE 118-bus system can validate the quality and efficiency of the proposed algorithm.