公开(公告)号：US10526010B2

公开(公告)日：2020-01-07

申请号：US16063428

申请日：2017-11-08

Applicant: NSK LTD.

Inventor： Takahiro Tsubaki ,  Haruhiko Kamiguchi ,  Tomohiro Miura ,  Nobuaki Kogure

IPC: B62D5/04 ,  H02H7/08 ,  H02P21/22 ,  H02P21/16

Abstract: An electric power steering apparatus includes a control substrate that controls a poly-phase motor having a multi-system motor winding, including a temperature sensor that detects a substrate temperature of said control substrate; and a coil temperature estimating section that obtains coil calorific values of respective phases of said poly-phase motor and a substrate calorific value of said control substrate by a motor current of said phase, and estimates a coil temperature of said phase by said coil calorific value, said substrate calorific value and said substrate temperature based on a heat transfer phenomenon between said respective phases that is caused by a difference in temperature between coils of said respective phases and a heat transfer phenomenon between said coil and said control substrate.