Investigation of several new technologies for mega city power grid issues

New challenges are rising with the fast development of power grids in mega cities, especially huge short circuit current levels and reduced voltage stability. In this paper, two solutions based on new technologies are proposed. The first solution consists of a new short circuit fault current limiter (called DYNACUR) together with STATCOMs (called SVC Light). Another consists of voltage source converter based HVDC (HVDC Light) together with a small short circuit fault current limiter(DYNACUR). The schemes and their corresponding performances are investigated based on a mega city power grid similar to Shanghai. The results show that both proposed solutions are effective. The costs and benefits are compared related to the approximate performance. Finally, two real cases of STATCOMs and HVDC Light are introduced briefly.