In AC/DC hybrid distribution network with power electronic transformer (PET), the topology is more complex and the operation mode is more flexible. As a result, it is of significance to study the state estimation method of hybrid network. This paper starts from PET steady state model considering the converter loss, and then analyses its control method for AC/DC hybrid network. By adding the virtual nodes, a unified state estimation model for power electronic equipment is established. The pseudo-measurement equation is formulated according to the control equation of power electronic equipment to improve the redundancy of data. Finally, a state estimation method for AC/DC hybrid networks with PET is proposed. A test case of an AC/DC hybrid network with PET is used to verify the effectiveness of the proposed method.
Keywords Power Electronic Transformer (PET), Steady State Model, Hybrid AC/DC Network, Three-Phase State Estimation, Pseudo-Measurements