The hybrid cascaded high-voltage direct-current (HVDC) system

combining the advantages of line-commutated converters (LCC) and modular multilevel converters (MMC)

exhibits promising engineering application potential. This paper conducts research on the prediction and suppression of subsequent commutation failures in such systems. First

the risk of subsequent commutation failures caused by both the interaction between controllers during each phase of the commutation failure recovery period and commutation voltage sags was clarified. Secondly

after considering the DC voltage interactions between MMC and LCC terminals and the roles of controllers in the hybrid cascaded HVDC system

a prediction method for subsequent commutation failures is proposed by comparing the effective value of commutation voltage with a threshold voltage. Then

a coordinated control strategy is presented

involving continuous reactive power support from MMC and dynamic modification of the extinction angle reference in constant extinction angle control (CEAC)

to achieve suppression of subsequent commutation failures. Finally

an electromagnetic transient simulation model of the hybrid cascaded system is established in PSCAD/EMTDC

verifying the accuracy of the prediction method and the effectiveness of the suppression strategy.