INVESTIGATION ON FAULT ENERGY DISSIPATION FOR MVDC DISTRIBUTION NETWORK

The medium voltage direct current (MVDC) power distribution system is the promising direction of the future distribution network. However, there exist some problems including large fault current, high short-circuit energy and long energy dissipation time, which restrict the development of DC distribution network. Therefore, this paper studies the key issues of fault energy dissipation in MVDC distribution system. By comparing the differences between different current limiting and breaking schemes and analysing the distribution and dissipation characteristics of the system short-circuit energy, the key factors affecting the short-circuit energy and energy dissipation time are extracted. Then the simulation cases based on the PSCAD/EMTDC platform are performed to verify the influence of different current limiting-breaking schemes and system parameters on energy dissipation results. Furthermore, by optimizing the parameter coordination between the converter, the fault current limiter (FCL) and the DC circuit breaker (DCCB), the capacity requirement of the energy dissipation module of DCCB is further reduced, and the short-circuit fault energy is quickly dissipated.