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. 24, 1998
Filed:
May. 20, 1997
Satoru Kaneko, Urizura-machi, JP;
Ryoso Masaki, Hitachi, JP;
Sanshiro Obara, Tokai-mura, JP;
Yuusuke Takamoto, Hitachi, JP;
Hitachi, Ltd., , JP;
Abstract
In a method and apparatus for motor control in an electric vehicle, current feedback control from an AC motor is performed using a digital arithmetic unit. The motor control equipment includes a power converter having a maximum output frequency of at least 500 Hz for driving the AC motor, and the digital arithmetic unit outputs an AC voltage command to the power converter based on current feedback from the AC motor up to the maximum output frequency of the power converter. The digital arithmetic unit includes a first subtractor for calculating the deviation between a detected value and a command value for the d-axis current, and a second subtractor for calculating the deviation between a detected value and a command value for the q-axis current. A phase calculator calculates a d-axis phase corresponding to the resistance and reactance components of the impedance of the d-axis, and a q-axis phase corresponding to the resistance components of the impedance of the q-axis. A voltage control calculator calculates control signals for the d- and q-axis voltages, due to the d-axis current deviation and the q-axis current deviation, based on the d-axis phase and the q-axis phase. The AC voltage command is output to the power converter based on the d- and q- axis voltage control signals.