Analysis on fast reclosing of line start permanent magnet motor with time-stepping finite element method

Reclosing on a rotating motor after a brief power-off can bring serious dangerous due to excessive current and torque transients, especially to permanent magnet motors of line start. To avoid such potential threats, time-stepping finite element method was used to study the transient processes under different reclosing conditions. Combined with the numerical and theoretical analysis, a practical criterion for favorable reclosing conditions is proposed, which is expected to prevent the permanent magnet motor from damages during reclosing.