Title:
METHOD FOR STARTING A BRUSHLESS D.C. MOTOR
Document Type and Number:
WIPO Patent Application WO2003052919
Kind Code:
A3
Abstract:
The invention relates to a method for starting a brushless d.c. motor comprising a multi-phase stator winding. According to the invention, a plurality of current pulses is applied to the stator winding while the rotor is stationary, a current build-up period is measured in the stator winding for each current pulse until a current threshold has been reached and the rotor position is derived from the current build-up periods that have been measured. The aim of the invention is to obtain a controlled acceleration without the use of a sensor and to precisely determine the rotor position without using complex control technology. To achieve this, a plurality of test current pulses is successively applied to the stator winding in such a way that the test current pulses in the stator generate stator flow vectors across 360 DEG , which are electrically offset by identical angular increments. The current build-up period is measured in the aggregate current of the stator winding for each stator flow vector and the phase angle of the stator flow vector with the shortest current build-up period is determined as the rotor position.
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Inventors:
HEIDRICH TORSTEN (DE)
Application Number:
PCT/DE2002/004582
Publication Date:
November 06, 2003
Filing Date:
December 16, 2002
Export Citation:
Assignee:
BOSCH GMBH ROBERT (DE)
HEIDRICH TORSTEN (DE)
HEIDRICH TORSTEN (DE)
International Classes:
H02P6/185; H02P6/22; (IPC1-7): H02P6/20; H02P6/16
Foreign References:
| US5117165A | 1992-05-26 | |||
| US5254914A | 1993-10-19 | |||
| US4876491A | 1989-10-24 |
Other References:
See also references of EP 1459436A2
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