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. 13, 2007
Filed:
May. 15, 2006
Pekka Jahkonen, Hyvinkää, FI;
Pekka Jahkonen, Hyvinkää, FI;
Kone Corporation, Helsinki, FI;
Abstract
The invention relates to an electric motor drive for operating an alternating-current motor. The electric motor drive comprises a frequency converter for controlling the motor, which frequency converter comprises a rectifier and an inverter implemented using semiconductor switches arranged in a bridge, and an intermediate circuit placed between the rectifier and the inverter and comprising a capacitor. According to the invention, the electric motor drive additionally comprises two regulating units, the first one of which contains an inductor unit provided at the input of the frequency converter and at the same time at the input of the rectifier, the inductors comprised in the unit being connected to each phase; and an intermediate circuit with a low-value capacitor, of the order of 50 μF, while the second one contains an auxiliary switch, to which the supply of electric power is arranged to occur via a safety relay, the auxiliary switch being so connected to selected semiconductor switches of the inverter bridge that the control signal for a selected semiconductor switch will pass via the auxiliary switch when the latter is in a conducting state; and a current measuring unit for measuring and/or monitoring the supply current to the electric motor.