What caused the large-scale power outage in Shanghai?

Power failure caused by equipment failure, such as short circuit and disconnection of overhead lines, cable failure, explosion of switchgear and other failures, usually takes a long time to troubleshoot and maintain. If you are an urban user, congratulations, because the urban distribution network structure is usually relatively developed, which can form a ring network, and the fault load can be transferred to other substations for power supply. This time is usually determined by the scope of the fault and the degree of automation of the local distribution network (once a substation with 10kV switchgear was destroyed by explosion in the most important area of a developed province, and the distribution network dispatch transferred all the loads of this substation in only 46 minutes. At this time, the cars going to the scene for treatment are basically stuck on the road because of traffic lights. However, if the power grid in rural areas is not developed enough, if the above accidents occur, the power supply can only be restored after the fault is solved slowly. Because all substations are unattended now, we must go to the substation to check the fault information first, then find the fault according to the information, and then take safety measures before maintenance. This usually takes more than 2 hours, and it usually takes the manpower of the whole power supply bureau to repair it for 3 or 4 days to restore power supply. At that time, the customer department of the power company will inform all the property power outage information the next morning.