Adaptive Control of Battery Energy Storage Systems for Suppression of Commutation Failures in Multi-Infeed HVDC System

The complexity of multi-infeed direct current (MIDC) systems has increased the risk of continuous DC commutation failures, posing a challenge to the stability of the power grid. The theoretical mechanism of continuous DC commutation failures during the transient process of ground faults in MIDC systems is clearly demonstrated, and the role of transient reactive power compensation by battery energy storage systems (BESS) in suppressing such failures is analysed. To tackle the limitations of conventional strategies, a staged reactive power control strategy based on the combined criterion of the magnitude of the AC voltage dip and the size of the extinction angle is proposed. This strategy dynamically adjusts reactive power during significant AC voltage dips, maintaining voltage support while minimizing adverse effects on the trigger delay angle during the fault recovery. In addition, the effect of the access location and capacity of the BESS on the suppression of continuous DC commutation failures. The results show that setting the BESS closer to the faulty DC receptor and increasing its capacity significantly improves the suppression effect and provides a practical guide for better stability of MIDC systems.