Reactive Power Control for Bidirectional Isolated High-Frequency Link Converter

Single stage dc-ac high-frequency link matrix converters (HFLC) are suitable for numerous applications where dc-ac conversion is required along with voltage matching and/or galvanic isolation. However, when bidirectional and reactive power processing is required, HFLCs lack effective modulation methods that would allow for operation without additional circuits or reduced performance. This paper presents a phase-shift modulation (PSM) method suited for bidirectional operation of HFLC. The proposed modulation can be used for both rectifier and inverter operating modes, with control over the power factor. Zero voltage switching (ZVS) of the dc-side switches and zero current switching (ZCS) of the ac-side switches is achieved in all operating conditions. Furthermore, two switches operate at line frequency, eliminating their switching loss. There is no need for auxiliary circuits and the same commutation principles are used in both power conversion directions. The modulation was verified on a PSIM simulation model