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:
Oct. 04, 2011
Filed:
Jul. 26, 2007
Yutaka Higuchi, Tokyo, JP;
Yutaka Higuchi, Tokyo, JP;
Mitsubishi Electric Corporation, Chiyoda-Ku, Tokyo, JP;
Abstract
To reduce, in a power converting apparatus for an electric locomotive, a sixth-order harmonic noise induced by a torque ripple component equivalent to a sixth-order frequency of an inverter frequency. When a motor is driven in a three-pulse mode to drive the electric locomotive, three pulses included within a ½ cycle of the inverter frequency in a PWM waveform, which is used for controlling a switching element of an inverter unit that drives the motor, are set to satisfy Tq≧T/8, Tp≦Tq/2, and Tr≦Tq/2 where, assuming that the three pulses include a first pulse, a second pulse, and a third pulse from an order of generation, Tp is a pulse width of the first pulse, Tq is ½ of a pulse width (full width at half maximum of a pulse) of the second pulse, Tr is a pulse width of the third pulse, and T is a cycle of the inverter frequency.