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:
Jul. 06, 1999
Filed:
May. 26, 1998
Sanshiro Obara, Tokai-mura, JP;
Kazuyoshi Sasazawa, Hitachinaka, JP;
Nobunori Matsudaira, Hitachi, JP;
Hitachi, Ltd., , JP;
Abstract
In a driving system comprising a permanent magnet type synchronous machine, an electric power converter for the synchronous machine and a driving controller for driving the electric power converter, the driving controller comprises a current command generator for generating a d-axis current command and a q-axis current command of the synchronous machine, a d, q-axis current control uni for generating AC voltage command values Vu*, Vv* and Vw* based on the d-, q-axis currents from the synchronous machines, and a PWM control unit for generating driving signals for the electric power converter based on the AC voltage command values. A phase generator generates a phase signal from zero-cross point information of the AC voltage command values and a phase difference angle .delta. between induced voltage and terminal voltage of the synchronous machine; and a magnet temperature compensating unit generates a phase signal from zero-cross point information of the AC voltage command values and a phase difference angle .delta. of a .delta.-table storing phase difference angles .delta. between induced voltage and terminal voltage of the synchronous machine. The phase difference angle .delta. is compensated based on a magnet temperature.