Assessment of Virtual Synchronous Machine based Control in Grid-Tied Power Converters

This paper presents the assessment of virtual synchronous machine (VSM) control schemes applied to grid-tied power converters. Specifically, the paper analyzes first the merits of its usage in reactive power static compensators (STATCOM), and second in generic grid-tied inverters. VSM is compared against standard d-q frame vector control, and key operational aspects like synchronization and startup procedure are discussed in detail. The paper considers both VSM-based and inverter-synchronous machine duality based models for the development of control schemes. As a particularly important outcome of this duality study, it will be shown how converter synchronization can be, in general, realized by scaling down and integrating DC-link voltage of any voltage source converter. The concepts presented will be demonstrated experimentally with a 30 kVA 208 V ac synchronous generator and power converter test bed.