Dispatchable Current Source Virtual Oscillator Control Achieving Global Stability

TL;DR

This paper presents a novel dispatchable current source virtual oscillator control (dCVOC) for grid-following converters, ensuring global stability and avoiding low-voltage transients, verified through high-fidelity simulations.

Contribution

It introduces a new dCVOC scheme that guarantees steady-state equilibrium and global stability, addressing issues like low-voltage transients and weak grid instability.

Findings

Ensures global stability under various grid conditions.

Avoids low-voltage transients and weak grid instability.

Validated through electromagnetic transient simulations.

Abstract

This work introduces a novel dispatchable current source virtual oscillator control (dCVOC) scheme for grid-following (GFL) converters, which exhibits duality with dispatchable virtual oscillator control (dVOC) in two ways: a) the current frequency is generated through reactive power control, similar to a PLL ; b) the current magnitude reference is generated through active power control. We formally prove that our proposed control always admits a steady-state equilibrium and ensures global stability under reasonable conditions on grid and converter parameters, even when considering LVRT and current saturation constraints. Our approach avoids low-voltage transients and weak grid instability, which is not the case for conventional GFL control. The effectiveness of our proposed control is verified through high-fidelity electromagnetic transient simulations.