Repetitive controller to compensate for odd harmonics

Details Repetitive controller to compensate for odd harmonics Repetitive controller to compensate for odd harmonics

2011-03-08

2011-03-08

Bullock, Jr., Lewis A (Department: 2193)

Electrical computers: arithmetic processing and calculating

Electrical digital calculating computer

Particular function performed

C708S309000, C708S311000, C700S044000, C700S045000

Reexamination Certificate

active

07904495

ABSTRACT:
A repetitive controller scheme with negative feedback and feedforward introduces infinitely many poles on the imaginary axis located at the resonant peaks. The feedforward introduces zeros, which produce notches located in between two consecutive resonant peaks. The latter has the advantage of making the controllers more selective, in the sense that the original overlapping (appearing at the valleys) or interaction between consecutive resonant peaks is removed by the notches. This would allow, in principle, peaks of higher gains and slightly wider bandwidth, avoiding, at the same time, the excitation of harmonics located in between two consecutive peaks. A negative feedback compensator with feedforward is especially useful when only the compensation of odd harmonics is required, but not the even harmonics, like in many power electronic systems. In contrast, the positive feedback controller would try to reinject, and indeed amplify, any small noise, which has components on the even frequencies. The negative feedback repetitive controller includes a simple Low Pass Filter (LPF). This modification restricts the bandwidth of the controller, and at the same time reinforces the stability when the controller is inserted in a closed-loop system.

REFERENCES:
patent: 4852034 (1989-07-01), Takayama
patent: 4920507 (1990-04-01), Takeda
patent: 5563794 (1996-10-01), Cosner et al.
patent: 5638794 (1997-06-01), Kubo et al.
patent: 5740090 (1998-04-01), Steinbuch et al.
patent: 5856934 (1999-01-01), Nakajima et al.
patent: 7123850 (2006-10-01), Hamby et al.
patent: 7145746 (2006-12-01), Hirano et al.
patent: 7265932 (2007-09-01), De Hoog
patent: 2003/0004591 (2003-01-01), Fontana et al.
Hara et al, Repetitive Control System: A New Type Servo System for Periodic Exogenous Signals, IEEE Transactions on Automatic Control, vol. 33, No. 7, Jul. 1988.
Broberg et al, A New Approach to Phase Cancellation in Repetitive Control, Industry Applications Society Annual Meeting, 1994., Conference Record of the 1994 IEEE.
Steinbuch, Repetitive control for systems with uncertain period-time, Automatica 38 (2002), p. 2103-2109.
Lin et al, Compensation of MR Head Non-Linearities Using a Saturable Transfer Function, IEEE Transactions on Magnetics, vol. 36, No. 5, Sep. 2000.
Bodson et al, Harmonic Generation in Adaptive Feedforward Cancellation Schemes, IEEE Transactions on Automatic Control, vol. 39, No. 9, Sep. 1994.
Costa-Castello et al, Odd-Harmonic Digital Repetitive Control of a Single-Phase Current Active Filter, IEEE Transactions on Power Electronics, vol. 19, No. 4, Jul. 2004.
Non-final Office Action in U.S. Appl. No. 11/217,682, mailed Jun. 12, 2009, 7 pages.

Affiliated with

Also associated with

Rating

Repetitive controller to compensate for odd harmonics does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Repetitive controller to compensate for odd harmonics, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Repetitive controller to compensate for odd harmonics will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2686355