The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 25, 2025
Filed:
Jun. 01, 2022
Hitachi Astemo, Ltd., Hitachinaka, JP;
Hitachi Astemo, Ltd., Hitachinaka, JP;
Abstract
A synchronous motor driving device which accurately estimates and limits direct current (DC), without a dedicated current detection sensor. The device includes a first DC calculation unit that calculates a first DC based on a first voltage command value, a current value of a winding of a synchronous motor, and a battery voltage; a second DC calculation unit that calculates a second DC based on a current value of the winding of the synchronous motor, a rotation speed of the synchronous motor, and a predetermined motor characteristic; a model error extraction unit calculating inverter efficiency based on the first and second DC; a DC correction unit that calculates an estimated DC on the basis of the first and second DC, and the inverter efficiency; and a DC limiting unit that corrects a current command value of the winding based on the estimated DC and a predetermined DC limit value.