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:
Feb. 10, 2015
Filed:
Jun. 23, 2011
Hideki Ayano, Tokai, JP;
Katsumi Ishikawa, Hitachinaka, JP;
Kazutoshi Ogawa, Hitachi, JP;
Tsutomu Kominami, Hitachinaka, JP;
Mami Kunihiro, Hitachi, JP;
Hideki Ayano, Tokai, JP;
Katsumi Ishikawa, Hitachinaka, JP;
Kazutoshi Ogawa, Hitachi, JP;
Tsutomu Kominami, Hitachinaka, JP;
Mami Kunihiro, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
Temperature rise in semiconductor switching element that is part of a power conversion device is estimated to assess the degradation and remaining lifetime of the switching element. This is accomplished with a heat generation amount calculation unit in a calculation processor, where current command values Id* and Iq* and voltage command values vu*, vv* and vw* are used to calculate a chip loss. Current values iu*, iv* and iw* of all output phases are estimated from the current command values. The ON/OFF loss of the chip is represented by a function of an estimated value for a current flowing in each output phase, and the loss can be derived by integration with a PWM carrier frequency f. With respect to a conduction loss, a conduction time is integrated with the estimated current value and a saturation voltage, which is a function of the estimated current value.