The traditional protection and control of distribution network face a considerable challenge due to the integration of a large number of distributed generators(DGs). In order to solve problems of active distribution network

a distributed fault self-healing scheme based on smart terminal unit(STU)is proposed. The scheme uses current differential protection and fault current amplitude comparison as the fault location principle

which is adaptive to the active distribution network with different DG types and penetration rates. Under the condition that all load switches are circuit breakers

the scheme can realize the fast location

isolation of faulted sections and the power restoration of non-faulted sections. The scheme fully considers the coordination with anti-islanding protection and low voltage ride-through of DGs. Each STU has the function of automatic network topology recognition

therefore can change the related control strategy based on real-time network topology. Finally

using the developed STUs

a closed loop test of a 10 kV active distribution network is carried out on RTDS platform. The test result shows that the scheme can adapt to the change of network structure

and the self-healing time is within one second.