A Vector Control Strategy for a Multi-Port Bidirectional DC/AC Converter With Emphasis on Power Distribution Between DC Sources

A vector control strategy applied to a multi-DC-port bidirectional DC/AC converter is presented in this paper, which can distribute the power of each DC source in a wide range. Port vectors corresponding to each DC port are defined, and the relationship between port vector and port power is analyzed, which maps the distribution of DC port power to the composition of port vectors. By controlling the magnitude and phase of the port vectors, the magnitude and direction of power flow are controlled for each corresponding port, even with a very low voltage of an auxiliary DC port. Compared with traditional n-level SVPWM, the number of vectors is reduced from 3n to n, which leads to an easier control strategy in multi-port converters. Several typical scenarios are shown in this paper. And the proposed vector control strategy is verified in MATLAB/Simulink.