Screening Index of Severe AC Faults in Multi-infeed HVDC System Considering Electromagnetic Transient Process

The existing AC fault screening indicators for multi-infeed HVDC systems cannot accurately reflect the AC-DC coupling effect and DC electromagnetic transient process, and it is difficult to accurately evaluate the impact of AC faults on DC operation. Therefore, this paper proposes an AC fault screening index for multi-infeed systems that takes into account the fault transient process. Firstly, the electromechanical-electromagnetic hybrid simulation model of the multi-infeed HVDC system is constructed based on PSD-PSModel; secondly, considering the AC-DC coupling effect and the DC control link, the multi-infeed AC-DC interaction factor (MIADIF) and Continuous commutation failure time window (CCFTW) indicators can accurately reflect the impact of AC faults on the electromagnetic transient process of key state variables of a multi-infeed system. Finally, a simulation of a multi-infeed HVDC system is carried out. Validation and analysis verify the effectiveness of the proposed indicators.