Study on hybrid control strategy for bi-directional power conversion system

In view of harmonic current problems existing in the bi-directional energy control of power conversion system (PCS), an hybrid control strategy of current waveform based on bi-directional main circuit topology is presented. In order to decrease the volume and weight of filter inductance in the DC side, a method of multiple carrier phase-shifting is adopted to restrain ripple and reduce switching loss of converter. In order to improve the power quality of the AC side, total harmonic distortion (THD) in grid-connected current of converter is effectively restrained and high dynamic response speed is ensured. On this basis, a 100kW bi-directional energy storage converter has been developed. The effectiveness and feasibility of the proposed control strategy are verified by the experimental results.