| Abstract |
A bipolar multi terminal HVDC transmission system has been investigated, particularly with respect to a safe and fast recovery after different types of disturbances in the AC and DC systems. Overvoltage phenomena caused by DC line-to-ground faults possibly lead to commutation failures in the unfaulted pole if no preventive measures are taken. In this respect the influence of two parallel DC lines per pole, the station power rating, the location of the station, and the location of the fault is discussed. The fault recovery times applying both DC circuit breakers and conventional fault clearing by DC current zero in the affected pole are compared at DC line faults and faults within a station. |
