Patent ID: 11926378
Assignee: NIDEC CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC B  H | IPC B  H

Claim 9:
10. A power steering comprising:
a drive controller;
a three-phase motor that is driven under control of the drive controller; and
a power steering mechanism that is driven by the three-phase motor, wherein
the drive controller comprises:
an electric value calculation unit configured to calculate an electric value in each of coordinate axes of rotating coordinates of the three-phase motor based on an electric value that is at least one of a current value or a voltage value generated in the three-phase motor;
a sign information storage unit storing sign information; and
a fault determination unit configured to
combine, for each of the coordinate axes, positive-negative information on at least one of
(i) a difference between the electric value calculated by the electric value calculation unit and a target electric value indicating a control target of an electric value in said each of the coordinate axes, or
(ii) a variation of the difference, and

determine, among phases of the three-phase motor, a phase with the sign information coinciding with the combined positive-negative information as a fault phase having a fault, and

the drive controller is configured to, in response to determining the fault phase, switch control of the three-phase motor to a control of the three-phase motor under abnormal conditions.