Bus differential protection method for realizing sectional dead zone protection based on virtual bus

The invention relates to a bus differential protection method for realizing sectional dead zone protection based on a virtual bus. The bus differential protection method comprises the following steps: independently arranging a bus differential protection device for each section of bus in a plurality of single bus sections; virtualizing the corresponding bus according to the position and the quantity of sectional switches connected with each section of bus; after the current equivalence of each sectional switch is taken, calculating into a side bus differential protection device logic; and when a dead zone in a sectional switch generation zone fails, jumping the sectional switch at the side and then sending out a command to jump a virtual bus sectional switch or borrowing a bus differential protection exit loop of a virtual bus self. The bus differential protection method has the benefits that due to the arrangement of the virtual bus, when the dead zone in the generation zone fails, a CT signal is not required to be alternately sealed by a side bus differential protection device and an opposite side bus differential protection device; the protection function of dead zone failure of the sectional switches is realized inside the side bus differential protection device through the virtual bus; and an external signal is not required to be connected, so that a connecting line between the side bus differential protection device and the opposite side bus differential protection device is reduced.