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Patent Searching and Data

Document Type and Number:
Japanese Patent JP4313203
Kind Code:
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 muF, 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.

Jahkonen, Pekka
Application Number:
Publication Date:
August 12, 2009
Filing Date:
November 13, 2002
Export Citation:
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International Classes:
H02P27/06; H02M1/08; H02M1/088; H02M5/458; H02M7/48; H02M7/797; H02P3/22
Domestic Patent References:
Attorney, Agent or Firm:
Takao Katori