A method of reactor turn-to-turn protection, comprising: determining a virtual zero sequence voltage U • 0 ' based on an actual zero sequence current I • 0 f; and/or determining a virtual negative sequence voltage U • 2 ' based on an actual negative sequence current I • 2 f; determining a zero sequence operation quantity ( U op. 0) and a zero sequence restraining quantity ( U res. 0) based on an actual zero sequence voltage U • 0 and the virtual zero sequence voltage ( U̇ 0 '); and/or determining a negative sequence operation quantity ( U op.2) and a negative sequence restraining quantity ( U res. 2) based on an actual negative sequence voltage U • 2 and the virtual negative sequence voltage U • 2 ′; and performing a turn-to-turn protection when the zero sequence operation quantity ( U op. 0) is greater than the zero sequence restraining quantity ( U res. 0), and/or when the negative sequence operation quantity ( U op.2) is greater than the negative sequence restraining quantity ( U res.2); calculating the virtual zero sequence voltage U • 0 ′, U • 0 ' = − I • 0 f Z L + Z s 0 '; Wherein I • 0 f represents the actual zero sequence current, Z L represents phase reactance of the reactor, Z s0 ' represents neutral point reactance; calculating the virtual negative sequence voltage U • 2 ′; U • 2 ' = − I 2 f • Z L; I • 2 f represents the actual negative sequence current, Z L represents phase reactance of the reactor; U o p.0 = | U • 0 − U • 0 ' |; U r e s.0 = | U • 0 + U • 0 ' |; U op.0 represents the zero sequence operation quantity, U res. 0 represents the zero sequence restraining quantity, U̇ 0 represents the actual zero sequence voltage, U • 0 ′ represents the virtual zero sequence voltage; U o p.2 = | U • 2 − U • 2 ' |; U r e s.2 = | U • 2 + U • 2 ' |; U op.2 represents the negative sequence operation quantity, U res. 2 represents the negative sequence restraining quantity, U • 2 represents the actual negative sequence voltage, U • 2 ′ represents the virtual negative sequence voltage. determining a virtual zero sequence voltage U • 0 ' based on an actual zero sequence current I • 0 f; and/or determining a virtual negative sequence voltage U • 2 ' based on an actual negative sequence current I • 2 f; determining a zero sequence operation quantity ( U op. 0) and a zero sequence restraining quantity ( U res. 0) based on an actual zero sequence voltage U • 0 and the virtual zero sequence voltage ( U̇ 0 '); and/or determining a negative sequence operation quantity ( U op.2) and a negative sequence restraining quantity ( U res. 2) based on an actual negative sequence voltage U • 2 and the virtual negative sequence voltage U • 2 ′; and performing a turn-to-turn protection when the zero sequence operation quantity ( U op. 0) is greater than the zero sequence restraining quantity ( U res. 0), and/or when the negative sequence operation quantity ( U op.2) is greater than the negative sequence restraining quantity ( U res.2); calculating the virtual zero sequence voltage U • 0 ′, U • 0 ' = − I • 0 f Z L + Z s 0 '; Wherein I • 0 f represents the actual zero sequence current, Z L represents phase reactance of the reactor, Z s0 ' represents neutral point reactance; calculating the virtual negative sequence voltage U • 2 ′; U • 2 ' = − I 2 f • Z L; I • 2 f represents the actual negative sequence current, Z L represents phase reactance of the reactor; U o p.0 = | U • 0 − U • 0 ' |; U r e s.0 = | U • 0 + U • 0 ' |; U op.0 represents the zero sequence operation quantity, U res. 0 represents the zero sequence restraining quantity, U̇ 0 represents the actual zero sequence voltage, U • 0 ′ represents the virtual zero sequence voltage; U o p.2 = | U • 2 − U • 2 ' |; U r e s.2 = | U • 2 + U • 2 ' |; U op.2 represents the negative sequence operation quantity, U res. 2 represents the negative sequence restraining quantity, U • 2 represents the actual negative sequence voltage, U • 2 ′ represents the virtual negative sequence voltage.