The secondary arc problem of the half-wavelength transmission lines is very serious.If the secondary arc is not promptly extinguished

it would lead to the failure of the single-phase auto-reclosing.Considering the particularity of the half-wavelength transmission line structure

we proposed an on-line suppression method of secondary arc based on the instantaneous power injection.With the establishment of the half-wavelength transmission line model and the secondary arc model

the method was analyzed and studied.Results show that the proposed arc arc suppression method can effectively reduce the amplitude of secondary current and recovery voltage along the transmission lines

so as to speed up the arc extinction

improving the success rate of the single-phase auto-reclosing.The suppression technique can be used as an effective control measure for the secondary arc of the half-wavelength transmission line

but its practical application technology still needs to be further studied.