US00573 1965A
United States Patent [191
[11]
[45]
Cheng et al.
[54] POWER LINE HARMONIC REDUCTION BY
HYBRID PARALLEL ACTIVIUPASSIVE
FILTER SYSTEM WITH SQUARE WAVE
INVERTER AND DC BUS CONTROL
[75] Inventors: Po-Tai Cheng; Subhashish
Bhnttacharya; Deepakraj M. Divan.
all of Madison. Wis.
5,731,965
Mar. 24, 1998
D.M. Divan. “Non Dissipative Switched Networks for High
Power Applications". Electronics Letters. vol. 20. No. 7 . pp.
277-279. Mar. 1984.
EZ. Peng. et al.. “A New Approach to Harmonic Compen
sation in Power Systems”. IEEE-IAS Conf. Rec. pp.
874-880. 1988.
Hideaki Fujita & Hirofumi Akagi. “A Practical Approach to
Harmonic Compensation in Power Systems-Series Con
nection of Passive and Active Filters—”. IEEE-IAS Conf.
Rec.. pp. 1107-1112. 1990.
Assignee: Wisconsin Alumni Research
Foundation. Madison. Wis.
(List continued on next page.)
Primary Examiner-Stuart N. Hecker
Attorney, Agent, or Firm--Foley & Lardner
Appl. No.: 669,010
Filed:
Patent Number:
Date of Patent:
Jun. 21, 1996
Int. Cl.6 ............................ .. H02M 1/12; H02M 1/14
[57]
ABSTRACT
US. Cl. .............................. .. 363/41; 363140.307/105
Field of Search .......................... .. 307/105; 327/552;
A hybrid parallel active/passive ?lter system is provided
363/40. 41
sation for power systems connected to high power non
linear loads. The hybrid ?lter includes a passive ?lter
which provides line power harmonic isolation and compen
References Cited
connected in series with an active ?lter inverter. The active
U.S. PATENT DOCUMENTS
?lter inverter is controlled to generate inverter voltages such
that the ?lter terminal voltage tracks the supply voltage
4,053,820 10/1977
Peterson et al. .
harmonics at a selected dominant harmonic frequency to
5,198,746 3/1993
5,329,222 7/1994
5,355,025 10/1994
5,465,203 11/1995
Gyugyi et al. .
Gyugyi et a1. .
regulate the supply current harmonics to zero. A synchro
nous reference frame (SRF) based controller is used to
generate harmonic inverter voltage commands based on
measured supplyr current values. A feed forward command
signal generator may be used to improve the response of the
control system The active ?lter inverter is preferably imple
5,513,090
5,548,165
5,567,994
5,614,770
4/1996
8/1996
Moran et al. .
Bhattacharya et al. .
Bhattacharya et al. .
Mohan et al. .......................... .. 363/39
10/1996 Davis et al. .
3/1997
363/41
Suelzle .............................. .. 307/105
OTHER PUBLICATIONS
L. Gyugyi & E.C. Strycula. “Active AC Power Filters".
[BEE-1A8 Conf. Rec.. pp. 529-535. 1976.
N. Mohan. et al., “Active Filters for AC Harmonic Suppre
sion”. lEEE/PES Winter Power Meeting. pp. 168-174.
1977.
I. Takahashi & A. Nabae. “Universal Power Distortion
compensator of Line Commutated Thyristor Converter”,
Proc. IEEFJIAS Annu. Meeting. pp. 858-864. 1980.
Hirofumi Akagi, et al.. “Instantaneous Reactive Power Com
pensators Comprising Switching Devices without Energy
Storage Components". IEEE Trans. Indus. App., vol. IA-20.
No. 3. pp. 625-630. 1984.
mented as a square-wave inverter. The active ?lter inverter
DC bus is controlled to achieve power balancing and to
provide real power to compensate for losses of the inverter.
Power balancing is achieved by exchanging energy at the
fundamental and dominant harmonic frequency of the active
?lter inverter. Control of the active ?lter inverter to achieve
DC bus control and harmonic isolation simultaneously is
accomplished using DC bus control inverter voltage com
mand signals generated at the fundamental frequency in
combination with harmonic inverter voltage command car
rier signals at the dominant harmonic frequency to form low
frequency switching signals for the square-wave inverter
switching devices.
54 Claims, 38 Drawing Sheets
5,731,965
Page 2
UI‘HER PUBLICATIONS
H. Akagi. “New Trends in Active Filter". EPE ‘91 Conf.
Rec.. vol. 0. pp. 017-026. 1995.
N. Balbo. et al.. “Hybrid Active Filter for Parallel Harmonic
Mukul Rastogi. et al.. “Hybrid-Active Filtering of Har
monic Currents in Power Systems”. presented at the 1995
Compensation”.
Isao Takahashi. et al.. “Low Price and High Power Active
Filter”. IEEE Japan National Convention. pp. E95-E98.
1991.
S. Bhattacharya. et al.. “Synchronous Frame Harmonic
isolator Using Active Series Filter". EPE’ 91 Conf. Rec..
vol. 3. pp. 30-35. Florence. 1991.
S. Bhattacharya. “A Uni?ed Power Flow Control to Flexible
AC Transmission Systems”. ECE 714 Project Report. Univ.
of Wisconsin-Madison. May 1992.
Hirohito Funato & Atsuo Kawamura. “Proposal of Variable
Active-Passive Reactance”. IEEE IECON Conf. Rec.. vol.
1. pp. 381-388. 1992.
Hirohito Funato & Atsuo Kawamura. “Analysis of Variable
Active-Passive Reactance”. IEEE PCC Conf. Rec.. pp.
647-652. 1993.
S. Bhattacharya. et al.. “Control and Reduction of Terminal
Voltage Total Harmonic Distortion (THD) in a Hybrid Series
Active and Parallel Passive Filter System”. IEEE PESC
Conf.Rec.. pp. 779-786. 1993.
IEIEIPES Winter Meeting. New York. I an. 29-Feb. 2. 1995.
Ned Mohan & Girish R. Kamath. “A Novel. Per-Phase
Interface of Power Electronic Apparatus for Power System
Applications". presented at NAPS 95. Bozeman. Montana.
1995.
J. Hafner. et a1. . “A Combined System of a Passive Filter and
a Shunt Active Power Filter to Reduce Line Current Har
monies”. Proc. 1995 IPEC. Yokohama. Japan. pp. 388-393.
1995.
S. Bhattacharya. et al.. “Optimizing Three Phase Current
Regulators for Low Inductance Loads”. IEEE-LAS Conf.
Rec.. pp. 2357-2364. 1995.
Subhashish Bhattacharya 8: Deepak Divan. “Synchronous
Frame Based Controller Implementation for a Hybrid Series
Active Filter System”. IEEE-IAS Con. Rec.. pp.
2531-2540. 1995.
S. Bhattacharya. et al.. “Active Filter Solutions for Utility
Interface”. [EEE-ISIE Conf. Rec.. pp. 53-63. 1995.
Hirohito Funato & Atsuo Kawamura. “Control of Variable
Subhashish Bhattacharya & Deepak Divan. “Design and
Active-Passive Reactance (VAPAR) and Negative Induc
Implementation of a Hybrid Series Active Filter Syste ”.
IEE PESC Conf. Rec.. pp. 189-195. 1995.
tance”. IEEE PESC Conf.. Rec.. pp. 189-196. 1994.
US. Patent
Mar. 24, 1998
Sheet 1 of 33
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Mar. 24, 1998
Sheet 3 of 38
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US. Patent
Mar. 24, 1998
Sheet 5 of 38
5,731,965
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US. Patent
Mar. 24, 1998
Sheet 17 of 38
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