Bidirectional half-bridge three-level DC-DC converter

In order to achieve bi-directional energy transmission regulation to maintain the stability of electrical energy, this paper proposes a circuit topology of bidirectional three-level half-bridge DC-DC converter. In the circuit topology, two half bridges connected in series, and the two half bridges are controlled to work at the same time so as to output three-levels. When the load connected to the left side, the bidirectional flow of energy can be controlled by controlling the phase difference between the left and right sides. Compared with similar converters based on full bridge arms, this topology can expand the voltage input range, decrease the number of switches, and reduce the voltage stress on components. The voltage balance between the two capacitors and the three-level output control is achieved through the proposed PWM and dual PI closed-loop overall control strategies. Experiments are made to demonstrate the validity of the analysis.