Low-Inertia Grid-Forming Control with Large Phase Angle Jump Capability for Converters With Small Energy Storage

Traditional Grid-Forming (GFM) converter control requires additional energy storage. The cost of additional storage makes GFM control less attractive for distributed generation than grid-following (GFL) control. Sufficiently small converter inertia may be solely provided by the DC-Link capacitor, avoiding the cost of additional hardware, while still improving grid stability locally. Reducing total system inertia without loss of stability is a challenging task that we tackled with the help of Linear Quadratic Gaussian (LQG) controller design. Like tradititional grid-forming control, the proposed control strategy allows operation under very low short-circuit ratio, while providing similarly tight DC link voltage regulation as GFL control.