A New Perspective for Power Oscillation in Paralleled DSG-VSGs System With Low-Frequency Pulsed Load

The paralleled DSG-VSGs system provides an effective solution for supplying the low-frequency pulsed load (LFPL). By strategically matching the number of paralleled VSGs to the peak power of the LFPL, the capacity requirement of the DSG can be significantly reduced. Nonetheless, the system encounters power oscillation issues, with the oscillation characteristics varying in response to LFPL pulse frequency and peak-to-average ratio. For this, a transient power deviation model is established to elucidate the power oscillation mechanism, and the underlying causes of oscillation intensification due to LFPL are explored. Moreover, the impact of the pulse frequency and peak-to-average ratio on oscillation characteristics is analyzed. Then, a power oscillation suppression method is proposed to narrow the transient power deviation between the VSGs and DSG, which incorporates a transient compensation component within the VSG excitation system. Thus, the active power oscillation caused by parameter mismatch is effectively suppressed, and the oscillation intensification due to LFPL is alleviated. Finally, experimental validation confirms theoretical analysis and control effectiveness.