Inlet wire emergency power supply automatic switch-in control method and system

The invention discloses an inlet wire emergency power supply automatic switch-in control method which is used for a sectionalized single-bus configuration circuit in a transformer substation, wherein the circuit comprises a first busbar, a second busbar, a bus coupler switch which is located between the first busbar and the second busbar and capable of controlling the connection and disconnection of the two sections of busbars, an inlet wire emergency power supply automatic switch-in device, a first main transformer connected with the first busbar, and a second main transformer connected with the second busbar; the method comprises the steps of after the first main transformer or the second main transformer does protective actions, judging whether the bus coupler switch is switched off, if yes, the inlet wire emergency power supply automatic switch-in device is controlled to act, and an emergency power supply starts to supply power; otherwise, the inlet wire emergency power supply automatic switch-in device is controlled to do no action, and the emergency power supply does not come into use. The method has less influence on the normal running of the transformer substation, and does not affect the safety of power grid and equipment. The invention also discloses an inlet wire emergency power supply automatic switch-in control system.