Current Source Mode Bidirectional DC/DC Converter With Multiple-Level Output Conversion Ratios Based on the Hybrid PWM Control of the Switched-Capacitor Structure

The current source (CS) mode bidirectional dc/dc converter (Bi-DCC) with multiple-level output current ratios is presented. Using the hybrid pulsewidth modulation (PWM) method to control the conversion selection mechanism realizes the multiple-level conversion options in both bidirectional energy flows. It is suitable for future all-electrical driving and braking systems in electric vehicles, supplying power to adjust the motor dynamics control during vehicle driving and collecting the energy generated during braking, especially on different road conditions. Moreover, the function that one single converter provides multiple-level conversion ratios, makes the design highly suitable for smart manufacturing as it can simplify the design by type and configuration variations. This design mainly focuses on dealing with applications directly powered by the CS, for example, the connection of photovoltaic (PV) units, CS mode motor controller, current-based power systems, and CS mode light-emitting diodes. A 300 W prototype with a conversion selection structure (CSS), which contains three switching orders and ten levels of current options, has been established. It validated multiple conversion ratio selections for step-down and step-up operation modes, high stability, and low power cost through the simulation and experiment results.