A Novel Topology of Hybrid DC Fault Current Limiter base on novel fault current limitation theory for DC Line Short Fault in HVDC System

Compared with the traditional AC power transmission system, the short-circuit current of HVDC grid dc side do not has natural zero-crossing, rises rapidly and is larger. Fault current limitation problem has become one of the major effects which constrain the development of high voltage DC transmission network. The most of existing current limitation theory is changing the impedance of DC transmission line by switching on some resistors or inductors in DC transmission line. In this paper, the proposed FCL reduce input voltage of limit current circuit of FCL by chopped wave technique and enhance ability of limit current of inductor by push-pull principle. Compared to other DC current limiters, This FCL not only limit rising rate of fault current in higher efficiency but also can limit the peak of fault current. The operation principle and limit theory is demonstrated in detail.