A dVOC-Based Mode-Switching Strategy for Grid-Forming Converters

To reduce the current and voltage surges when DERs changes from off-grid mode to grid-connected mode, a dispatchable virtual oscillator control-based mode-switching strategy for power converters is proposed. This paper analyzes the droop characteristic of the grid-forming converters, and realizes seamless mode-switching by introducing a virtual power-based pre-synchronization skill, the currents show no inrush when mode switches, and quick dynamic responses since the phase-locked loop is no more required. Finally, the availability of the mode-switching strategy is verified, and the converters applying this strategy have good dynamic performance and stability.