Dual Grid-Forming Converter

TL;DR

This paper introduces a dual grid-forming converter model inspired by synchronous machine symmetry, capable of unbalance compensation and robust recovery from large disturbances without needing a frequency signal.

Contribution

The paper presents a novel dual GFM control approach that independently manages active and reactive power, enhancing stability and unbalance compensation in grid converters.

Findings

Effective unbalance compensation without frequency signal

Robust recovery from large load outages and faults

Independent control of active and reactive power

Abstract

This letter proposes a dual model for grid-forming (GFM) controlled converters. The model is inspired from the observation that the structures of the active and reactive power equations of lossy synchronous machine models are almost symmetrical in terms of armature resistance and transient reactance. The proposed device is able to compensate grid power unbalance without requiring a frequency signal. In fact, the active power control is based on the rate of change of the voltage magnitude. On the other hand, synchronization and frequency control is obtained through the reactive power support. The letter shows that the proposed dual-GFM control is robust and capable of recovering a normal operating condition following large contingencies, such as load outages and three-phase faults.