A Study on Reactive Power Control Using Variable Gain and Voltage Limiter for Grid-Forming Converters

In our previous study, an active power control method called variable gain control (VGC) has been proposed for grid-forming (GFM) converters. In the present paper, a reactive power control method for GFM converters to prevent an overcurrent and an alleviate a voltage oscillation under a three-line-to-ground (3LG) fault. In the proposed method, the magnitude of the voltage output of GFM converters is varied in accordance with the terminal voltage. In addition, a novel idea of variable gain and a voltage limiter is applied to avoid overcurrent. Numerical simulations demonstrate the effectiveness of the proposed method in suppressing overcurrent and voltage variation during 3LG faults.