CA1166690A - Static reactive power compensator - Google Patents
Static reactive power compensatorInfo
- Publication number
- CA1166690A CA1166690A CA000390775A CA390775A CA1166690A CA 1166690 A CA1166690 A CA 1166690A CA 000390775 A CA000390775 A CA 000390775A CA 390775 A CA390775 A CA 390775A CA 1166690 A CA1166690 A CA 1166690A
- Authority
- CA
- Canada
- Prior art keywords
- transformer
- reactive power
- power
- static reactive
- power compensator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000003068 static effect Effects 0.000 title claims abstract description 9
- 239000003990 capacitor Substances 0.000 claims abstract description 20
- 238000004804 winding Methods 0.000 claims abstract description 17
- 238000006243 chemical reaction Methods 0.000 abstract description 6
- 230000000875 corresponding effect Effects 0.000 description 2
- 230000002730 additional effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 230000010349 pulsation Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for AC mains or AC distribution networks
- H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
- H02J3/1821—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators
- H02J3/1835—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators with stepless control
- H02J3/1864—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators with stepless control wherein the stepless control of reactive power is obtained by at least one reactive element connected in series with a semiconductor switch
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/10—Flexible AC transmission systems [FACTS]
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Control Of Electrical Variables (AREA)
Abstract
Abstract of the Disclosure Disclosed is a static reactive power compensator connected to the secondary winding of a power transformer. The compensator is formed of a parallel connection of fixed cap-acitors individually connectable to the power line and of thyristor-adjusted inductors, a booster transformer having phase-varying secondary windings being connected between the secondary winding of the power transformer and the thyristor-adjustable inductors. With this arrangement, the capacitors can be connected singly with little effort without a 6-pulse reaction occurring on the power line, and without the capacitors being loaded via harmonic currents of the 5th and 7th order.
Description
The invention relates to a static reactive power compen-sator connected to the secondary winding of a power transformer formed by a parallel connection of fixed capacitors individually connectable to a power line and thyristor-adjusted inductors. Such a compensator is described in "electro-warme international", No.
30 (1972~, pages 267 to 274.
To avoid the disadvantage of a 6-pulse reaction of such a configuration on the power line, 12-pulse configurations are used in manycases, where~y the formation that is required here of two 3-phase systems mutually offset by 30 is produced by two se-condary windings, one of which is star-connected and the other delta-connected (Wiss. Berichte AEG-TELEFUNKEN 49 (1976) No. 4/5, pages 198 to 203).
The variant indicated at the beginning without two se-condary windings of the power transformer has, as already mentioned, the disadvantage of a 6-pulse reaction (feedback). To keep the current harmonics of the 5th and 7th harmonics from the power line, a part of the capacitance can be developed to form correspond-ing filter circuits (frequency-selective circuits). However, these ~ 20 filters may not be switched off then if their effect is not to be lost. The inductive portion of the compensator must be amply laid out in accordance with the capacitive power of the filter circuits.
Thus, it may be necessary to provide a plurality of adjustable in-ductor branchea that are triggeredin succession so that the size of the harmonic oscillations produced does not increase excessive-ly. mhe inductor effort increases as well through this.
For the circuit variant with the two secondary windings '; offset in phase, the current harmonics of the 5th and 7th order of : ~, ., .
~, .
6~0 the individual secondary circuits nullify each other in the coupling transformer so that 12 pulsations are given. However, this applies only if both secondary circuits are loaded equally. If, for example one of the capacitor groups is switched off, the necessary symmetry is no longer given, and despite the additional effort for the transformer 6-pulse reactions on the power line result. For this reason, switching an individual capacitor branch off must be ruled out if need be. Despite the existence of two switchable capacitor branches, only a relatively coarse gradation is then lQ possible. Also, the one capacitor branch cannot be considered a redundancy to the second branch.
It is the purpose of the invention to design the reactive power compensator in such a way that the capacitors can be con-nected singly with little effort without a 6-pulse reaction occur-ring on the supply mains, and without the capacitors being loaded via harmonic currents of the 5th and 7th order.
This object is solved according to the invention in that a ~ooster transformer with phase-varying secondary windings is connected between the secondary winding of the power transformer and the thyristor-adjustable inductors.
With this 12-pulse circuit it is possible to obtain ab-solute symmetry with respect to the connector rail. The capacitor groups may advantageously be connected singly without having to accept a 6-pulse reaction. At the same time, *hrough the finer capacitive subdivision the inductor regulating unit used for the precision adjustment can be designed smaller. If need be the filter branchQs are mutually available as reserve. The finer sub-divis;on of the overall range of adjustment results in a more U
favourable loss characteristic. The capacitors are no longer load-ed via harmonic currents o~ the 5th and 7th order since they have already nullified each other in the booster transformer.
The invention will now be further explained in the fol-lowing on the basis of the exemplary embodiments illustrated in the drawing, in which:
Figure 1 shows the basic wiring of a reactive power com-pensator according to the invention with separate power and booster transformers.
Figure 2 shows the hasic wiring of a reactive power com-pensator with a booster transformer integrated in the power trans-former.
According to Figure l a static reactive power com-pensator, formed by the capacitors 4 and the inductors 1, is con-nected to a power line 7, the reactive power of which it is to compensate. The capacitors 4 are individually connectable to a bus bar 9 via thyristor switch 8. The bus bar 9 is connected on the one hand to the power line 7 via a power transformer 2, and on the other hand is connected to the inductors 1 via a booster transformer 3. The inductors 1 are continuously adjustable via the thyristors 10. The booster transformer 3 is provided with two secondary windings connected to the bus bars 11. The individ-ual thyristor-adjusted inductors 1 are connected to different bus bars 11.
The power transformer 2 can be designed as a usual two-winaing transformer with as small a specific short-circuit voltage Uk as possible. Through the small uk the voltage increase at the rail 9 in the capacitive range is held lower, which benefits the the capacitor design.
In the booster transformer 3, which can be designed as an autotransformer, a phase variation of ~ 15 occurs via the circuit of the secondary winding with respect to the bus bar 11, so that there is absolute symmetry with respect to the rail 9. Independent of the number of capacitors 4 connected via the switch 8, a 12-pulse compensation with respect to the power line 7 is achieved by excitation of the inductors 1 via the thyristors 10.
Figure 2 shows that the booster transformer 3 according to Figure 1 can also be integrated in the power transformer 2. If the capacitors 4 are delta-connected cyclically, as shown, to dif-ferent phases of the two secondary 3-phase systems 5, 6 that are brought out, then bringing out the intermediate voltage correspond-ing to rail 9 in Figure 1 can be dispensed with. Since the addit-ional voltages for the phase variation are each isolated, this connection of the capacitors is almost identical with the connection to the rail 9 which in this case is inaccessible.
In Figure 2 the inductors 1 are arranged radially.
However, a triangular arrangement is also possible, whereby the inductors 1 are each connected to the phases of one system, i.e.
to rl-sl; sl-tl; tL-rl; and r2-s2; s2-t2; t2-r2.
30 (1972~, pages 267 to 274.
To avoid the disadvantage of a 6-pulse reaction of such a configuration on the power line, 12-pulse configurations are used in manycases, where~y the formation that is required here of two 3-phase systems mutually offset by 30 is produced by two se-condary windings, one of which is star-connected and the other delta-connected (Wiss. Berichte AEG-TELEFUNKEN 49 (1976) No. 4/5, pages 198 to 203).
The variant indicated at the beginning without two se-condary windings of the power transformer has, as already mentioned, the disadvantage of a 6-pulse reaction (feedback). To keep the current harmonics of the 5th and 7th harmonics from the power line, a part of the capacitance can be developed to form correspond-ing filter circuits (frequency-selective circuits). However, these ~ 20 filters may not be switched off then if their effect is not to be lost. The inductive portion of the compensator must be amply laid out in accordance with the capacitive power of the filter circuits.
Thus, it may be necessary to provide a plurality of adjustable in-ductor branchea that are triggeredin succession so that the size of the harmonic oscillations produced does not increase excessive-ly. mhe inductor effort increases as well through this.
For the circuit variant with the two secondary windings '; offset in phase, the current harmonics of the 5th and 7th order of : ~, ., .
~, .
6~0 the individual secondary circuits nullify each other in the coupling transformer so that 12 pulsations are given. However, this applies only if both secondary circuits are loaded equally. If, for example one of the capacitor groups is switched off, the necessary symmetry is no longer given, and despite the additional effort for the transformer 6-pulse reactions on the power line result. For this reason, switching an individual capacitor branch off must be ruled out if need be. Despite the existence of two switchable capacitor branches, only a relatively coarse gradation is then lQ possible. Also, the one capacitor branch cannot be considered a redundancy to the second branch.
It is the purpose of the invention to design the reactive power compensator in such a way that the capacitors can be con-nected singly with little effort without a 6-pulse reaction occur-ring on the supply mains, and without the capacitors being loaded via harmonic currents of the 5th and 7th order.
This object is solved according to the invention in that a ~ooster transformer with phase-varying secondary windings is connected between the secondary winding of the power transformer and the thyristor-adjustable inductors.
With this 12-pulse circuit it is possible to obtain ab-solute symmetry with respect to the connector rail. The capacitor groups may advantageously be connected singly without having to accept a 6-pulse reaction. At the same time, *hrough the finer capacitive subdivision the inductor regulating unit used for the precision adjustment can be designed smaller. If need be the filter branchQs are mutually available as reserve. The finer sub-divis;on of the overall range of adjustment results in a more U
favourable loss characteristic. The capacitors are no longer load-ed via harmonic currents o~ the 5th and 7th order since they have already nullified each other in the booster transformer.
The invention will now be further explained in the fol-lowing on the basis of the exemplary embodiments illustrated in the drawing, in which:
Figure 1 shows the basic wiring of a reactive power com-pensator according to the invention with separate power and booster transformers.
Figure 2 shows the hasic wiring of a reactive power com-pensator with a booster transformer integrated in the power trans-former.
According to Figure l a static reactive power com-pensator, formed by the capacitors 4 and the inductors 1, is con-nected to a power line 7, the reactive power of which it is to compensate. The capacitors 4 are individually connectable to a bus bar 9 via thyristor switch 8. The bus bar 9 is connected on the one hand to the power line 7 via a power transformer 2, and on the other hand is connected to the inductors 1 via a booster transformer 3. The inductors 1 are continuously adjustable via the thyristors 10. The booster transformer 3 is provided with two secondary windings connected to the bus bars 11. The individ-ual thyristor-adjusted inductors 1 are connected to different bus bars 11.
The power transformer 2 can be designed as a usual two-winaing transformer with as small a specific short-circuit voltage Uk as possible. Through the small uk the voltage increase at the rail 9 in the capacitive range is held lower, which benefits the the capacitor design.
In the booster transformer 3, which can be designed as an autotransformer, a phase variation of ~ 15 occurs via the circuit of the secondary winding with respect to the bus bar 11, so that there is absolute symmetry with respect to the rail 9. Independent of the number of capacitors 4 connected via the switch 8, a 12-pulse compensation with respect to the power line 7 is achieved by excitation of the inductors 1 via the thyristors 10.
Figure 2 shows that the booster transformer 3 according to Figure 1 can also be integrated in the power transformer 2. If the capacitors 4 are delta-connected cyclically, as shown, to dif-ferent phases of the two secondary 3-phase systems 5, 6 that are brought out, then bringing out the intermediate voltage correspond-ing to rail 9 in Figure 1 can be dispensed with. Since the addit-ional voltages for the phase variation are each isolated, this connection of the capacitors is almost identical with the connection to the rail 9 which in this case is inaccessible.
In Figure 2 the inductors 1 are arranged radially.
However, a triangular arrangement is also possible, whereby the inductors 1 are each connected to the phases of one system, i.e.
to rl-sl; sl-tl; tL-rl; and r2-s2; s2-t2; t2-r2.
Claims (5)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A static reactive power compensator connected to the secondary winding of a power transformer formed by a parallel connection of fixed capa-citors individually connectable to a power line and thyristor-adjusted induct-ors, characterized in that a booster transformer with phase-varying secondary windings is connected between the secondary winding of the power transformer and the thyristor-adjustable inductors.
2. A static reactive power compensator according to claim 1, characterized in that the booster transformer is designed as an autotransformer.
3. A static reactive power compensator according to claim 1, charac-terized in that the secondary windings of the booster transformer cause a phase variation of + 15°.
4. A static reactive power compensator according to claim 1, 2 or 3 characterized in that the power transformer is designed as a two-winding transformer with a small, specific short-circuit voltage.
5. A static reactive power compensator according to claim 1, or 3, characterized in that the booster transformer is integrated in the power trans-former via additional phase-varying secondary windings, and the connectable capacitors are delta-connected cyclically to different phases.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3045574.4 | 1980-11-29 | ||
| DE3045574A DE3045574C2 (en) | 1980-11-29 | 1980-11-29 | Static reactive power compensator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1166690A true CA1166690A (en) | 1984-05-01 |
Family
ID=6118223
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000390775A Expired CA1166690A (en) | 1980-11-29 | 1981-11-24 | Static reactive power compensator |
Country Status (3)
| Country | Link |
|---|---|
| CA (1) | CA1166690A (en) |
| DE (1) | DE3045574C2 (en) |
| ZA (1) | ZA818272B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103238258A (en) * | 2010-12-01 | 2013-08-07 | Abb技术有限公司 | Reactive power compensator, computer programs and computer program products |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19748147A1 (en) * | 1997-10-31 | 1999-05-06 | Asea Brown Boveri | Static compensator for reactive power compensation in electrical power supply network |
| ATE308150T1 (en) * | 2000-08-18 | 2005-11-15 | John Vithayathil | CIRCUIT ARRANGEMENT FOR STATIC GENERATION OF A VARIABLE ELECTRICAL POWER |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2195860B1 (en) * | 1972-08-09 | 1976-08-13 | Jeumont Schneider |
-
1980
- 1980-11-29 DE DE3045574A patent/DE3045574C2/en not_active Expired
-
1981
- 1981-11-24 CA CA000390775A patent/CA1166690A/en not_active Expired
- 1981-11-27 ZA ZA818272A patent/ZA818272B/en unknown
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103238258A (en) * | 2010-12-01 | 2013-08-07 | Abb技术有限公司 | Reactive power compensator, computer programs and computer program products |
| CN103238258B (en) * | 2010-12-01 | 2017-03-22 | Abb技术有限公司 | Reactive power compensator, computer programs and computer program products |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3045574A1 (en) | 1982-07-01 |
| ZA818272B (en) | 1982-10-27 |
| DE3045574C2 (en) | 1985-06-05 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |