Passivity-Based Multi-Sampled Single-Loop Voltage Control for Grid-Forming VSCs

Grid-side current feedforward can effectively enhance the dissipativity for single-loop voltage control of grid-forming voltage source converters. However, the dissipative characteristic of converter output impedance is seriously impacted by the LC-filter parameters deviation. Moreover, the LC-filter resonance frequency should be designed larger than the critical frequency, which may impact the switching harmonics filtering. To address this challenge, a multi-sampling voltage control scheme is proposed with converter-side current, capacitor current, and capacitor voltage feedforward. First, the grid-side current feedforward is replaced by converter-side current and capacitor current feedforward, and the LC-filter resonance frequency can be freely designed. In addition, the dissipativity robustness is enhanced through the capacitor voltage feedforward. Finally, the effectiveness of the proposed method is demonstrated through simulation.