Patent · US Expired

Control device for electric motor

US7005828B2 · kind B2 · utility

393Cited by
9References
40Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJul 30, 2003
Grant dateFeb 28, 2006
Priority date
Expiry dateJan 28, 2024

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH02P2207/05
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

Corresponding to a target torque, the control device calculates a target value of a feature based on at least one of the length of a long axis of a current vector locus and the length of the short axis and further superimposes a superimposed current on a drive current for the motor, the superimposed current having a frequency different from the frequency of the drive current. Further, the control device detects an actual value of the feature based on at least one of the length of a long axis of a current vector locus of the superimposed current and the length of the short axis of the same and finally detects a phase angle of the motor based on the target value and the actual value for the feature. The manipulation of a detecting phase is performed by feedback of a feature obtained by the magnitude of the superimposed current. That is, when the actual feature is more than the target value, the detecting phase is advanced. Conversely, when the actual feature is less than the target value, the detecting phase is delayed.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.