DC equipment is very important in power supply system of subway, which directly affects the driving and metro operation. When the DC bus encounters a shell collision fault, it can quickly cut off fault current by setting frame protection to ensure the safety of the person and the equipment. In this paper, by introducing the principle and function of frame protection, optimization solutions are explored to reduce the probability of malfunction through case studies.

DC equipment  /  frame protection  /  malfunction  /  rail potential