Abstract: Focus on the stator winding insulation and voltage oscillation of variable frequency motor，the

transition process of the pulse voltage output by the frequency converter in the transmission path of stator windings，frequency conversion cables，reactors，etc was analyzed，the voltage equivalent mathematical models for stator winding turns，output reactors，and variable frequency cables were derived，and a Simulink simulation model was established and simulated. Taking typical loads of rolling mills in the metallurgical industry as an example，pulse voltage tests were conducted using high-power variable frequency motors and frequency converters to verify the changes in voltage slopes of different wire turns. For the voltage oscillation caused by different frequency conversion cables，the 2nd-order system fitting was used to analyze the voltage spectrum characteristics，and the reactor's suppression effect for voltage oscillation was also verified.

      Key words: vlotage slope du/dt；turn-insulating；voltage oscillation；inverter；variable frequency motor