Optimal parameters design of bidirectional buck-boost three-level DC-DC converter based on Pareto front for electrochemical energy storage

Abstract:
DC-DC converters are important means of "one cluster, one management" for battery clusters in electrochemical energy storage systems. They have technical characteristics such as bidirectional energy flow, bidirectional voltage boost and buck, three-level and multiplexing, and involve the comprehensive optimization of multiple system parameters. This paper proposes a parameter optimization design method for a bidirectional buck-boost three-level DC-DC converter for electrochemical energy storage based on the Pareto front. By decoupling the three-level, multiplexing bidirectional boost-buck DC-DC circuit, the coupling relationship between system parameters is analyzed, and a multi-objective optimization model based on the Pareto theory is established. The Pareto feasible domain and Pareto front corresponding to the DC-DC converter are solved, and the optimal solution in the Pareto front is obtained according to the engineering design goals. Finally, the optimality of the obtained design parameters is verified through experimental platform validation: the inductance is small enough, the switching frequency is high enough, and the device junction temperature and current ripple are close enough to the design boundaries.