Optimal planning approach of network topology and active power filter in port distribution network considering harmonic interaction influence

Considering the shorter electrical distances between multiple renewable distributed generators (RDGs) within the port’s electrical power distribution network (DN), the harmonic power loss of transmission lines and cranes is increased by the primary harmonic currents and harmonic interaction currents. Active power filters (APFs), though a proven solution for suppressing primary harmonic currents, are ineffective in suppressing harmonic interaction currents in DN. Direct current transmission lines with high harmonic impedance effectively suppress harmonic interaction influence (HII) between RDGs. An optimal hierarchical multi-objective planning approach is proposed to collaboratively plan the network topology and APFs and obtain a Pareto optimal solution set. The HII with the planned network topology and the selectable APFs was formulated using explicit formulas. The branch-and-cut algorithm and the non-dominated sorting genetic algorithms Ⅱ (NSGA-Ⅱ) were used to solve the hierarchical model. A comparative analysis of multiple solution algorithms demonstrated the effectiveness of the proposed approach in suppressing the total harmonic current distortion rate to less than 3.5%. Sensitivity analysis indicated optimal economic performance of network topology and APFs when the DC load ratio reaches 20%. Furthermore, considering the future expansion trend of the port, the expansion plan was analysed in this study with 21 bus nodes, 35 transmission lines, and 6 APFs.