A distributed three-phase state estimation method for active distribution network integrating different types of distributed generators (DGs) is proposed. Firstly

the models of three-phase DGs connected to grids are presented

DGs connected to grids are divided into two types: directly or through pulse width modulation (PWM) converters. The states of AC bus voltage

together with the states of DGs

are selected as state variables

which are estimated using weighted least squares (WLS). A feasible way to add pseudo-measurements for unmonitored DGs is introduced so as to enhance the observability. Furthermore

aimed at increasing computational efficiency and numerical stability

a distributed method that extends sub-areas and sets the estimated values of border buses as pseudo-measurements for the area proper is implemented. Finally

test results have verified the effectiveness of the proposal. This work is supported by National Natural Science Foundation of China (No. 51107032

No. 51277052

No. 61104045

No. 51407125).