Snubber combined with brake circuit in inverter for bifilar winding motor and surge suppression circuit embeded in such motor

摘要

PURPOSE: A snubber and a surge suppression circuit are provided to effectively reduce spike voltages of surge, while simplifying the circuit configuration. CONSTITUTION: A snubber(2') comprises a plurality of snubber diodes connected to the nodes of the cables and semiconductor switching elements, wherein the snubber diodes bypass the over voltage generated by the inductance of the cables during the turn-off operation of the semiconductor switching elements; a plurality of snubber condensers connected in parallel to the anodes of the snubber diodes and the DC link of the cables so as to be charged with the bypassed voltage; and a brake circuit(3) which discharges the snubber condensers by operating when the charge voltages of the snubber condensers and the DC link voltage of the inverter rise to the level higher than the predetermined voltage level.