Access to distributed generators(DGs)and changes in network structure have increased the complexity of state estimation and measurement placement in the active distribution network(ADN). A multi-objective mathematical model of measurement placement in the ADN is established that takes into account both the cost of placement and estimation accuracy of different network structures

in which the output uncertainty of DG is also considered. The output uncertainty of DG is modeled as a Gaussian mixed model(GMM)

and the correlation of DG is described by the off-diagonal elements in a measurement covariance matrix. In addition

the analytic hierarchy process(AHP)is used to determine the impact factors of the cost of placement

the mesh network as well as other network structures. The measurement placement is determined by the greedy algorithm. Simulation results based on IEEE 33-bus and a 119-bus distribution network have verified the efficiency and feasibility of the method proposed. This work is supported by National Natural Science Foundation of China(No. 51177093).