DCM-Based Zero-Voltage Switching Control of a Bidirectional DC-DC Converter With Variable Switching Frequency

• Published in: IEEE transactions on power electronics Vol. 31; no. 4; pp. 3273 - 3288
• Main Authors: Konjedic, Tine, Korosec, Lucijan, Truntic, Mitja, Restrepo, Carlos, Rodic, Miran, Milanovic, Miro
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.04.2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Bidirectional dc-dc converter; Circuits; DC-DC power converters; discontinuous conduction mode (DCM); Electric currents; Frequencies; Inductors; resonant switching transitions; Switches; Switching; Switching frequency; Switching loss; synchronous rectification; Transistors; Zero voltage switching; zero-voltage switching (ZVS); discontinuous conduction mode (DCM); synchronous rectification; zero-voltage switching (ZVS); Bidirectional dc–dc converter; resonant switching transitions
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2015.2449322

This paper investigates a control approach for achieving reliable zero-voltage switching transitions within the entire operating range of a conventional nonisolated bidirectional dc-dc converter that utilizes synchronous rectification. The approach is based on operation in the discontinuous conduction mode with a constant reversed current of sufficient amplitude, which is achieved by load-dependent variation of the switching frequency. This paper focuses on the obtained resonant voltage transitions and provides analytical models for determining the reversed current and timing parameters that would ensure safe, reliable, and highly efficient operation of the converter. In addition, the proposed approach solves the synchronous transistor's spurious turn-on and body diode reverse recovery induced issues, does not require any additional components or circuitry for its realization, and can be entirely implemented within a digital signal controller. The effectiveness and performance of the presented control approach was confirmed in a 1-kW experimental bidirectional dc-dc converter that achieved 97% efficiency over a wide range of output powers at switching frequencies above 100 kHz.