Title:
ODD HARMONICS REDUCTION OF PHASE ANGLE CONTROLLED LOADS
Document Type and Number:
WIPO Patent Application WO2003005547
Kind Code:
A3
Abstract:
The present invention relates generally to the reduction of odd harmonics of phase angle controlled loads. One embodiment relates to an apparatus for reducing odd harmonic currents introduced into an alternating current (AC) supply by a load (20) having a zero crossing detector (18) and a processor (14) coupled to the zero crossing detector. The zero crossing detector is coupled to the AC current supply for measuring voltage zero crossings of the AC current supply. The processor receives a user control signal (13) for controlling the load, such as, for example, a speed control, determines phase angles required at the voltage zero crossings of the AC current supply to implement the user control signal, and selectively modulating the phase angles when they are in a predetermined range of undesired phase angles in order to selectively reduce odd harmonics within the AC current supply.
Inventors:
BERRINGER KENNETH A
Application Number:
PCT/US2002/015724
Publication Date:
March 04, 2004
Filing Date:
May 16, 2002
Export Citation:
Assignee:
MOTOROLA INC (US)
International Classes:
H02M5/257; H02P23/00; H02M1/12; (IPC1-7): H02M5/293
Foreign References:
| GB2348749A | 2000-10-11 |
Other References:
PATENT ABSTRACTS OF JAPAN vol. 2000, no. 14 5 March 2001 (2001-03-05)
PATENT ABSTRACTS OF JAPAN vol. 1999, no. 05 31 May 1999 (1999-05-31)
PATENT ABSTRACTS OF JAPAN vol. 1999, no. 05 31 May 1999 (1999-05-31)
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