1.School of Electrical and Electronic Engineering, North China Electric Power University, Beijing 102206, China;2.China Electric Power Research Institute, Beijing 100192, China;3.State Grid Economic and Technological Research Institute Co., Ltd., Beijing 102209, China

For the complexity of operation mode of the power electronic transformer (PET) ports and their multiple combinations in hybrid AC/DC grid composed of several PETs, an optimal combination method of operation strategy for PETs based on generalized AC/DC droop control (GADDC) is proposed, the objective of which is to fully utilize the renewable energy while maintaining the stability operation of power system. The switching between different control modes of PET ports could be approximated by adjusting the coefficients of GADDC, which avoids importing integer variables in the non-linear programming model, thus effectively reducing the complexity of the proposed model. Based on this, a robust combined optimization model of PET operation strategy considering the uncertainty of renewable energy is established. Furthermore, a bi-level optimization method is adopted to solve the proposed model. Simulation results verify the effectiveness and feasibility of the proposed method.

This work is supported by National Key R&D Program of China (No. 2017YFB0903300) and National Natural Science Foundation of China (No. 51777065).