The DC choppers (DCCs) can not only effectively address the issue of surplus power caused by the grid faults at the receiving end of large-scale offshore wind power transmission systems

but also significantly reduce the load weight of offshore converter platforms

which are the key technologies for lightweight and reliable offshore wind power transmission systems. This paper presents a comprehensive review of various DCC technologies reported in recent literature. Firstly

the existing DCC topologies are classified and their technical routes are sorted out

with a comparative analysis of the characteristics of different technical routes. Secondly

the key technologies of DCCs are summarized

focusing on power electronic switches

snubber circuits

low DC-link voltage ripple control

voltage balancing

and energy absorption. Then

different technologies are compared based on topological and operational characteristics. Finally

various challenges related to the design of DCCs are discussed from an engineering application perspective

with a view to advancing the development of DCC technologies.