A Simplified Index of Fast Evaluation of Commutation Failure Risk in Multi-infeed HVDC Systems

Considering the actual operation conditions and the general conditions of simulation calculations, this paper presents a simplified critical AC-DC system voltage interaction factor (SCADVIF) index and a method to fast evaluate the commutation failure risk of multi-infeed HVDC systems. The method still does not require modeling power system components in detail for dynamic simulation. By calculating and comparing all the ADVIFs and SCADVIFs of an AC/DC system, the receiving-end AC buses at which faults are applied may cause commutation failure of multi-infeed HVDC system can be found quickly: if ADVIF(jm) >= SCADVIF(jm), a fault occurring at receiving-end system AC bus m would result in commutation failure at HVDC j. In this way, it is possible to quickly identify all AC buses where a three phase fault would cause single or multiple commutation failures. The validity and accuracy of the proposed approach are demonstrated by comparing with simulations results using an actual planning large power grid. The proposed method instead of time-domain simulation analysis tool greatly reduces the computing time of researchers, and improves their work efficiency. The proposed index and method can be widely used in the planning, design and operation of AC/DC power grids.