Switching High Voltage DC Power in Branching Units of Large-scale Cabled Seafloor Observatories

2018 5th International Conference on Coastal and Ocean Engineering

Zheng, Shaoduo^1 ; Lyu, Feng^1

School of Ocean and Earth Science, Tongji University, Shanghai, China^1

关键词: Branching units;    DC voltage level;    High voltage DC;    HVDC circuit breakers;    Seafloor observatories;    Series-connected;    Switching operations;    Voltage balance;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/171/1/012006/pdf
DOI  :  10.1088/1755-1315/171/1/012006

来源: IOP

【 摘 要 】

Cabled Seafloor Observatories(CSOs) are powered by shore stations with DC voltage levels up to -10kV. When a backbone or spur cable fault occurs, the power system must isolate the fault by disconnecting the faulty segment quickly. So the BUs installed in the backbone cable need to carry out the switching operation under high voltages(HV). However, DC circuits have no zero-current points and the fault currents will rise rapidly, bringing a big challenge to the switching on/off operation. In this paper, we have purposed an HVDC circuit breaker based on series-connected IGBTs with voltage balance. Under the backbone voltage of -10kV and a peak current of around 14A, the simulation results show that the proposed design is feasible, with the switching-off time about 1ms.