Bidirectional Power Conversion Techniques in Electrical Systems

Bidirectional power conversion techniques enable controlled energy flow in both directions between sources, storage elements and the grid, addressing the growing need for efficient integration of renewable generation, electric vehicles and grid services. Central to these systems are converter topologies that allow seamless reverse and forward power transfer, typically realised through DC–DC, DC–AC and AC–DC stages. Non-isolated bidirectional DC–DC converters offer compact designs and high efficiency for low-voltage applications, while isolated configurations such as dual-active-bridge (DAB) converters provide galvanic separation and high power density for medium- to high-voltage platforms. Control strategies revolve around phase-shift modulation, resonant switching and advanced control loops to achieve soft-switching, fast dynamic response and optimal efficiency under varying load and voltage conditions. Recent advances in wide-bandgap semiconductors, digital control and electro-thermal co-modelling have further elevated performance, enabling robust solutions for vehicle-to-grid interaction, microgrid stability and bidirectional charging infrastructures. These developments underscore the global significance of bidirectional conversion in decarbonising energy systems and enhancing grid resilience.

Research from Nature Portfolio

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Research from all publishers

Researchers have developed an electro-thermal co-modelling approach for onboard chargers in hybrid and fully electric vehicles, integrating GaN and SiC devices within a single simulation environment. This method captures both electrical switching dynamics and thermal behaviour, enabling accurate device sizing, improved control robustness and reduced development time for bidirectional AC/DC–DC converter architectures.

A novel power management scheme for DC microgrids employs dual-active-bridge converters to balance renewable input and battery storage. A nonlinear robust control algorithm maintains common-bus voltage stability under constant-power loads and dynamic interactions, while a state-of-charge-based strategy optimises power sharing between photovoltaic arrays and energy storage units in islanded operation.

A modular input-series/output-parallel DC–DC converter has been proposed for low-speed electric-vehicle fast chargers. By arranging multiple DAB modules in series and parallel, the design achieves high charging power from a single-phase supply with uniform current sharing. Direct current-sharing control obviates the need for complex voltage-sharing loops, ensuring stable operation under parameter mismatches.

Bidirectional Power Conversion Techniques in Electrical Systems publication trend

The graph below shows the total number of articles in bidirectional power conversion techniques in electrical systems across all publications each year (not limited to Nature Index journals).

Technical terms

Bidirectional converter: Power electronic device allowing energy flow in both forward and reverse directions.

Dual-active-bridge (DAB): Isolated DC–DC converter topology with two H-bridge circuits and a high-frequency transformer.

Phase-shift modulation: Control technique adjusting the relative timing of bridge voltages to regulate power flow and achieve soft-switching.

Zero-voltage-switching (ZVS): Soft-switching condition in which the voltage across a power switch is zero at turn-on, reducing switching losses.

Wide-bandgap semiconductor: Semiconductor material (e.g., GaN, SiC) with high breakdown voltage and switching frequency capabilities.

Microgrid: Locally controlled network of distributed energy resources and loads that can operate connected to or isolated from the main grid.

References

1. Topologies and Control Schemes of Bidirectional DC–DC Power Converters: An Overview. IEEE Access (2019).
2. Electro-Thermal Model-Based Design of Bidirectional On-Board Chargers in Hybrid and Full Electric Vehicles. Electronics (2021).
3. Bidirectional Power Sharing for DC Microgrid Enabled by Dual Active Bridge DC-DC Converter. Energies (2021).
4. Development of Modular DC-DC Converters for Low-Speed Electric Vehicles Fast Chargers. Alexandria Engineering Journal (2021).