Wind energy is the most useful type of renewable energy and wind farms are also expanding following the development of renewable energy and energy marketing. One of the types of wind farms used in the world are offshore wind farms with a length of more than 200 km, which use HVDC lines. the key concern of the offshore wind farms extensive implementation is its sensitivity in the short circuit faults. Increasing the short-circuit level and fast raising nature of the DC fault currents are some reasons for importance of protection system and choosing the appropriate protection component that is critical issue for development of offshore wind farms. Breakers are one of the main components of protection and therefore choosing a suitable breaker is vital. Breaker main features in various types of DCCB is different based on its topology characteristic. This paper aim to survey breaker main features in types of DCCBs. @en

This article presents a novel high-temperature superconductive (HTS) power flow controller and current limiter (PFCCL), which limits fault currents and manages power flow in the intended transmission line. The proposed device includes series HTS reactors, HTS controlling dc coil, recovery resistive coil, and power electronic switches, which protects the microgrid from the upstream ac grid, short-circuit faults, and it controls the power flow between a microgrid and the upstream grid. Performance of the proposed PFCCL is mathematically analyzed, utilizing MATLAB and Maxwell software, and then validated by laboratory scaled-down experimental setup. It is shown that the simulation results are in fair agreement with the developed experimental laboratory setup results.@en