Study on monitoring and self-healing method of AC tampering fault

The intrusion of AC into the DC system will cause protection misoperation and a large area of power grid blackout accident. There are two reasons for AC intrusion into the DC system: first, the on-site safety measures are not in place, and the maintenance personnel are negligent in the wrong wiring of the line, resulting in AC/DC mixed connection. Second, due to equipment quality, aging and other problems lead to equipment insulation performance failure, resulting in AC/DC circuit short circuit. Ac/DC mixed short circuit will bury a huge hidden danger to the safe operation of the State grid..