Common Mode Circulating Currents Suppression and Power Distribution Methods of Parallel SOPs

Due to the limited capacity of a soft open point (SOP), multiple SOPs are typically paralleled to enhance the power transfer between the grids. Therefore, this paper develops a reliable control scheme for parallel SOPs. However, the parallel SOPs can lead to common mode circulating currents, increasing power losses. Based on this challenge, this paper proposes a common mode circulating currents suppression method that effectively suppresses the low frequency components of the circulating currents. Additionally, this paper explores the power automatic distribution methods of the parallel SOPs, with the capability of smooth switching between grid connected and islanded states. Finally, simulation models are established in MATLAB/Simulink and Typhoon HIL, and the results validate the effectiveness of the proposed methods.