Patent ID: 9685829
Date: 2017-06-20
CPC Classifications: B60L,H02K,Y02T

Claim:
1. A railroad-vehicle drive system comprising: a permanent magnet-type motor; an inverter that includes switching elements formed of a wide band-gap semiconductor and that drives the permanent magnet-type motor; and a control unit that controls the inverter, wherein the permanent magnet-type motor includes a rotor core in which magnet insertion holes are arranged in a convex shape, facing a center of a rotor, the magnet insertion holes having a plurality of permanent magnets embedded therein for each pole, wherein a permanent magnet group for each pole having the plurality of permanent magnets includes vent holes passing through the rotor core in an axial direction between one of the magnet insertion holes in which the permanent magnets are embedded and adjacent one of the magnet insertion holes or between the one of the magnet insertion holes and outer circumferential portions of the rotor core, wherein the control unit controls the inverter with a target current constant, in an entire control area up to a maximum number of revolutions of the permanent magnet-type motor, and wherein the magnet insertion holes and the vent holes are alternately arranged in a substantially U-shape to be convexed toward a center of the rotor.