US3671901A - Anti-harmonic transformer - Google Patents

Anti-harmonic transformer Download PDF

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Publication number
US3671901A
US3671901A US107048A US3671901DA US3671901A US 3671901 A US3671901 A US 3671901A US 107048 A US107048 A US 107048A US 3671901D A US3671901D A US 3671901DA US 3671901 A US3671901 A US 3671901A
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single phase
primary
windings
secondary windings
phase transformers
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US107048A
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Jacques Francois Marie-Jos Lys
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/34—Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/34—Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
    • H01F27/38—Auxiliary core members; Auxiliary coils or windings
    • H01F27/385—Auxiliary core members; Auxiliary coils or windings for reducing harmonics

Definitions

  • ABSTRACT Devices for eliminating in a three-phase voltage transformer T, separating two networks A and B the voltage harmonics preexisting within the three phase voltage feeding A and detrimental to B, or the current harmonics generated by B and detrimental to A.
  • the devices include single phase transformers, the primary windings of which are delta" coupled and the secondary windings of which are star" coupled, the angles determined by the legs of the triangles and of the stars exhibiting unique values, together with single phase autotransformers for connection to the A and B networks.
  • T need only be con stituted of two single phase transformers the primary secondary windings of which are in quadrature together with single phase transformers, the windings of which are connected to specific current taps provided on the above-mentioned transformers. They can be used in installations for electroehemistry, electrometallurgy, power distribution of dc. current and for installations of static power conversion.
  • the present invention relates to polyphase voltage transformers for removing voltage and current harmonics from electrical networks which are connected by the transformers. For example, if the transformer separates a first from a second network with the power passing from the first to the second, it can protect the second network from the harmonics existing in the first network. Similarly, if the second network includes nonlinear elements which generate current harmonics, the present invention prevents such harmonics from being transferred to the first network.
  • electrical polyphase voltage transformers are conventionally provided with symmetrical" windings whether or not they include single phase elements with independent circuits and star or polygon coupled electrical circuits, or include windings arranged on a single magnetic circuit with free or forced flux. They generally include a primary winding and a secondary winding for which are used conventional connection arrangements such as star", delta", mesh and so forth.
  • the third harmonics and their multiple can normally be eliminated.
  • the electromotive force includes a frequency three times as high as the fundamental and generates in the delta circuit a current whose frequency is also triple, which almost completely suppresses the third harmonic and supplies the necessary ampere-toms for a correct compensation of the flux within the magnetic cores, whether the transformers are free or forced flux types.
  • This latter property is, furthermore, used more particularly for star-star coupled large transformers with delta arranged tertiary windings.
  • FIGS. 1 and 2 are schematic diagrams of transformer couplings in accordance with this invention.
  • FIG. 3 is a geometric representation of the relationship between windings determined in accordance with this invention.
  • FIG. 4 is a schematic diagram of transformer windings geometrically arranged in accordance with this invention.
  • FIGS. 5 through 8 are schematic diagrams of geometric arrangements of transformers connected in accordance with this invention.
  • FIG. 9 is a geometric representation of the relationship between windings for eliminating voltage and current harmonies in accordance with the principles of this invention.
  • FIGS. 10 and II are schematic diagrams of yet other windings geometrically arranged to eliminate voltage and current harmonics.
  • the present invention embodies with a three-phase system, a transformer 5 T made of two single phase transformers I and 2 the primary and secondary windings of which are electrically intercoupled in a "quadrature (see FIGS. 1 and 2).
  • the quadrature" coupling hereafter referred to is actually the coupling characterizing the three phase windings of the socalled Scott configuration, one of the windings having m times less winding turns than the other, and one of its ends being connected to the middle point of the other, both thus including the altitude and the base of an equilateral triangle, according to the classical conventional representation.
  • This quadrature" coupling for the couplings l and 2 has two possible arrangements: in the first, both transformers l and 2 have the same transfonnation ratio B equal to the transformation ratio of T; in the second, the transformers respectively have for a transformation B being the transformation ratio of T.
  • Transformers 1 and 2 are provided with intermediary current taps H and h on their respective windings and, between these taps, filtering" transfonners are provided.
  • the triangles ABC and abc have centers 0 and 0 which stand for the primary and secondary voltage triangles and their respective origins, two regular pentagonal contours centered in O and 0 can be formed having particular vertices A B C and 0 b,,, c,. These vertices are precisely carried by AH and BC for the first and by ah and be for the second transformer.
  • the voltages across the terminals of a winding or part of it can be shown as the voltage diagram of the transformer and, similarly the segments shown as the diagram of voltages may represent the windings or part of windings at the terminals of which the voltages represented by these segments can be recovered.
  • Segments A,B,, A,C,, 0 b u e which are seen in FIG. 3, represent the windings of the single phase transformers linking v the unique points A,,, 8,, C,,, a b,, c
  • FIG. 4 is a diagrammatical representation of the device after both transformers have been arranged, the primary and secondary windings respectively connecting the unique taps bearing subscript 5. If a system of three phase sinuoidal voltages is applied to ABC, a system of voltages which are also three phase and sinuoidal will appear at abc; if moreover, the network fed in abc includes nonlinear impedances (rectifiers, thyristors or the like) the feeding currents will comprise, apart from the fundamental harmonics, all orders and, particularly, the fifth harmonics and their multiples.
  • wound circuits A,B C and a b,,c, taking into consideration the unique points or positions of the tap of subscript 5, have the property of only including, so far as currents with a frequency of five times the fundamental frequency is concerned, homopolar currents which are phase equal currents to which the impedance presented by A,B,C and a,b,c,, is very low.
  • a filtering single phase transformer (Adi, tub respectively, at the level of the primary and secondary windings of the transformers 11 and 12, between. the intermediary taps A 8,, a -b the positions of which on the associated primary and secondary voltage diagrams are such that 0A, 08,, on, 0b, and the angles formed by CA, and OB, and 0a, and ob, are equal to a whole number of 2 11/1 radians.
  • This condition can be written in accordance with the following expressions:
  • tg is the trigonometric tangent.
  • the transformer (A,B, a,b,) is arranged according to FIG. 6 between the taps A B, at the primary and ab, at the secondary winding; the tap b, extending from the winding b and the taps A B a b,, being so arranged that the triangles A,B H, and a,b,h,, with center 0, are geometrically similar and that 0a is equal to 0b, it is possible under the same conditions as above to remove the harmonics of sequence i.
  • the current taps A 8,, a,, b, between which the filtering transformer (A,B, o b is arranged are such (according to FIG. 6) that:
  • FIGS. 5 and 6 extend to the harmonic of sequence i, the above mentioned property characterizing the delta coupled windings of conventional three phase transformers with respect to eliminating third order current harmonics and their multiple;
  • the anti-current harmonics" three phase transformer is thus characterized by the assembly of the two transformers 11-12 and 61 -62 and the associated single phase transformers (A 8, a,b,) as described hereabove.
  • a balanced three-phase system is liable to cause theappearance of current harmonics of sequences 3,5,7,l 1,13,17,19, etc. each one susceptible to being eliminated by the method hereabove described.
  • the 5th and 7th harmonics can be substantially reduced through the embodiment of a single transformer (A 8, 11 b,) linking the taps A 8,, a b such according to the arrangement of FIG. 5
  • harmonics 11 and 13 could be substantially eliminated by the use of a single phase transformer linking the taps having the subscript l2, harmonics l7 and 19 being in turn eliminated by a single phase transformer of subscript l8 and so on.
  • harmonics l3 and 17 could be damped by a transformer linking the taps of subscript 15.
  • this invention may apply to any polyphase system and is not restricted to three-phase systems; in particular, when the anti-current harmonic transformer also multiplies the number of phases.
  • FIG. 7 illustrates this property showingthe transformation of a conventional classical three phase system to a five-phase system: the transformer 71 comprises three windings, viz.: AH at the primary, a 11, and tab, at the secondary; the transformer 72 comprises two windings, viz.: BC at the primary and be at the secondary.
  • Embodying suitable single phase transformers across the taps at the unique positions, according to the same principles as above outlined, allows eliminating current harmonics the number and the importance of which are reduced posed of single phase windings respectively arranged in quadrature.
  • the devices according to the second category'set forth at the beginning of the description enable voltage and currentharmonics of any i'sequence to be eliminated. They embody three single phasetransformers, as shown in FIG. 8, transformers which are 81, 82 and 83.
  • the transformer 81 is formed by a primary AB, and a secondary a,b,.
  • the transformer 82 is formed by a primary AC, and a secondary up
  • the transformer 83 is formed by a primary so, and secondary b,c,
  • the primary windings are delta coupled (dissymetrical) and the secondary are star coupled (also dissymetrical), with center 0.
  • Feeding the primary windings A,B,C, occurs through autotransformers AH and BC which are themselves power supplied in A, B, C.
  • Intermediary taps are provided on these autotransformers the position of which are such that:
  • the secondary windings are star coupled at and the end sections me, of the. star are, according to FIG; 8, connected by asingle phase transformer an; intermediary current taps b and c are provided on this autotransformer so that the end section b, of the star and the points b and 0 form an equilateral triangle, the center 0 of which is the same as that of the triangle a,b,c,.
  • a B and C represent the voltages at the diagram of FIG. 9 and, with relation to FIG. 8, the 3 particular vertices of a regular polygon having i sides cen tered in 0.
  • the transformation ratios of transformers 81, 82 and 83 are:
  • the present apparatus is reversible, this meaning that fed with athree-phase voltage at b,, b, c it will also exhibit at A, B, C a three-phase voltage free from any harmonics of rank i.
  • this arrangement can filter current harmonics of rank i in the same way as the devices of the above described first category. 1
  • Each harmonic can be eliminated through a set of three single phase transformers 81, 82 and 83, fed through adequate taps provided on the autotransformers AH and BC.
  • the secondary windings such as ca are series connected so as, one with the others the secondary windings such as or, and also the secondary windings such as 0b,.
  • the primary windings of the type A,B are parallel" arranged across the taps of the type A 8, set on All and BC whereas the secondary windings of the type ob, are series arranged in confonnity with FIG. 10; a single phase autotransformer is inserted between the end taps a and c of the secondary winding, and this single phase autotransformer is provided with intermediary current taps b and c in the same position as set forth above.
  • This series arrangement is likewise reversible and embodies 3n single phase transformers and three single phase autotransforrners, n being the number of harmonics of odd rank andof prime numbers with relation one to the other that were to be eliminated.
  • the devices according to the first category can'be used for all polyphase networks( generally three-phase) which have to be protected from the influence of current harmonics.
  • This influence from harmonics is always a drawback and often causes power losses through eddy current, overheating, resonances and overvoltages, operation instability, radioelectrical disturbances and so forth.
  • the anti-current harmonic" transformer can be used with'or without conversion of the number of phases before rectifiers and power thyristors: the current harmonics that the, latter often generate are detrimental in a general way to the network through which they are fed. Thisis the case for certain installations such as batteries charging, traction, electrochemistery, electrometallurgy, power supply for radio transmitters, power distribution through high voltage dc. current, and so forth.
  • the devices according to the second category can eliminate voltage and current harmonics.
  • the anti-harmonics transformers thus defined are not only used for the application above-mentioned, but may also be used after certain generators supplying a periodical wave which is not purely sinuoidal such as inverters and static cycloconverters, particularly when those apparatus are assisted, that is when they feed an already existing network which commands frequency and voltage form.
  • Apparatus for eliminating harmonics comprising a transformer coupling a first network to a second network, said transformer comprising two single phase transformers including respective primary windings connected in quadrature and respective secondary windings connected in quadrature, said primary windings being electrically connected together by connecting one end of one of said primary windings to a tap point on the other of said respective primary winding, said secondary windings each being electrically connected to a tap point on the other of said respective secondary windings, said tap points being located at the midpoints of said other of said respective primary and secondary windings, said primary windings having 3/2 times the number of turns of said respective secondary windings, said primary and secondary windings being provided with intermediary taps designated A, and B, on said primary windings and a, and b, on said secondary windings, the subscript i representing the odd harmonic to be eliminated, the positions of said taps being defined as:
  • k is a whole number or null and the designated geometrical segments represent the number of associated winding turns and H and h are the midpoint taps of said respective primary and secondary windings; and two further single phase transformers including primary and secondary windings and having a transformation ratio B, the primary windings and secondary windings of said two further single phase transformers being arranged across the taps A, and 8,, and a, and b. respectively.
  • said apparatus comprises a three phase transformer having a transformation ratio B comprising two single phase transformers electrically coupled together, the respective primary windings of said single phase transformers being electrically connected together by connecting one end of said primary of one of said single phase transformers to the midpoint of the other primary, said midpoint being designated as H, the respective secondary windings of said single phase transformers being electrically coupled together by connecting one end of the secondary of the other of said single phase transformers to the midpoint of the secondary of said one of said single phase transformers, said latter midpoint being designated h, N and n designating the number of winding turns of the primary and secondary windings of said one of said single phase transformers and N and n the number of winding turns of the primary and secondary windings of said other of said single phase transformers, the transformation ratios )9, and ,8: if said single phase transformers being:
  • k has simultaneously the same value andin which the designated geometrical segments represent winding parts and for one same coil the number of winding turns of the winding portions they stand for; the primary and secondary windings of at least one of said further single phase transformers having a transformation ration of 3.
  • Apparatus according to claim 1 wherein the parameter k is null and the subscript i is equal to half the sequence sum of the two following harmonics which are to be eliminated.
  • Apparatus for eliminating harmonics comprising (a) first and second autotransformers respectively designated AH and BC, said autotransformers being electrically connected togetherwith a connection of one end of autotransformer AH to the midpoint H of the second autotransformer BC, a current tap A. on said autotransformer AH, a pair of current taps B, and C, on said autotransformer BC, (b) three single phase transformers including primary windings designated A,B,, ac, and GA, current taps A,, B C being coupled in accordance with the following relationship:
  • k is a whose number or null and in which the designated geometrical segments represents the number of turns of the associated winding sections, the secondary windings of said single phase transformer being designated 1gb, Inc, and 0,0, and respectively conforming to the following relationship:

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Supply And Distribution Of Alternating Current (AREA)
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US107048A 1970-01-19 1971-01-18 Anti-harmonic transformer Expired - Lifetime US3671901A (en)

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FR7001717A FR2074686B1 (enrdf_load_stackoverflow) 1970-01-19 1970-01-19

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US (1) US3671901A (enrdf_load_stackoverflow)
CH (1) CH538774A (enrdf_load_stackoverflow)
DE (1) DE2102233A1 (enrdf_load_stackoverflow)
FR (1) FR2074686B1 (enrdf_load_stackoverflow)
GB (1) GB1340256A (enrdf_load_stackoverflow)
NL (1) NL7100149A (enrdf_load_stackoverflow)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4106089A (en) * 1976-09-10 1978-08-08 The Garrett Corporation Alternating current power dividing or combining system
US4471231A (en) * 1982-05-27 1984-09-11 Kabushiki Kaisha Komatsu Seisakusho Alternating current feeder system for trolley-assisted dump trucks
US4493016A (en) * 1982-10-07 1985-01-08 Westinghouse Electric Corp. Rectifier transformer
US4513243A (en) * 1983-06-08 1985-04-23 Westinghouse Electric Corp. Core form transformer for selective cancellation of subsynchronous resonance
US4638177A (en) * 1985-11-14 1987-01-20 Westinghouse Electric Corp. Rotating flux transformer
US4639610A (en) * 1985-12-10 1987-01-27 Westinghouse Electric Corp. Rotating flux transformer
US4833583A (en) * 1987-01-23 1989-05-23 Trailigaz-Compagnie Generale De L'ozone Electric supply device for an ozonizer
US5063487A (en) * 1990-03-22 1991-11-05 The United States Of America As Represented By The Secrectary Of The Navy Main and auxiliary transformer rectifier system for minimizing line harmonics
US5206539A (en) * 1991-11-15 1993-04-27 Power Distribution, Inc. Transformer with cancellation of harmonic currents by phase shited secondary windings
US5343080A (en) * 1991-11-15 1994-08-30 Power Distribution, Inc. Harmonic cancellation system
US5434455A (en) * 1991-11-15 1995-07-18 Power Distribution, Inc. Harmonic cancellation system
US5446642A (en) * 1992-05-11 1995-08-29 Electric Power Research Institute, Inc. Harmonic blocking converter system
US5515264A (en) * 1992-05-11 1996-05-07 Electric Power Research Institute, Inc. Optimized high power voltage sourced inverter system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2596195B1 (fr) * 1986-03-24 1989-03-31 Commissariat Energie Atomique Procede et dispositif de transmission de courants electriques triphases par un systeme de connexion amovible sans contact

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE160887C (enrdf_load_stackoverflow) *
US1227415A (en) * 1911-08-07 1917-05-22 Westinghouse Electric & Mfg Co Transformer.
CH127635A (de) * 1926-08-16 1928-09-01 Bbc Brown Boveri & Cie Einrichtung zur Herstellung eines künstlichen Nullpunktes zum Anschluss von Löschspulen an Dreiphasennetze.
DE492873C (de) * 1925-06-20 1930-03-04 Bbc Brown Boveri & Cie Einrichtung zur Herstellung eines anzapfbaren Nullpunktes in Dreiphasennetzen zum Anschluss von Nullpunktsdrosselspulen
GB495370A (en) * 1936-02-11 1938-11-11 Siemens Ag Improvements in or relating to three-phase transformers and three-phase choking coils
US2975357A (en) * 1958-09-26 1961-03-14 Gen Electric Transformer
US2989685A (en) * 1956-07-27 1961-06-20 Elin Ag Fur Elek Sche Ind Regulating transformer

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE160887C (enrdf_load_stackoverflow) *
US1227415A (en) * 1911-08-07 1917-05-22 Westinghouse Electric & Mfg Co Transformer.
DE492873C (de) * 1925-06-20 1930-03-04 Bbc Brown Boveri & Cie Einrichtung zur Herstellung eines anzapfbaren Nullpunktes in Dreiphasennetzen zum Anschluss von Nullpunktsdrosselspulen
CH127635A (de) * 1926-08-16 1928-09-01 Bbc Brown Boveri & Cie Einrichtung zur Herstellung eines künstlichen Nullpunktes zum Anschluss von Löschspulen an Dreiphasennetze.
GB495370A (en) * 1936-02-11 1938-11-11 Siemens Ag Improvements in or relating to three-phase transformers and three-phase choking coils
US2989685A (en) * 1956-07-27 1961-06-20 Elin Ag Fur Elek Sche Ind Regulating transformer
US2975357A (en) * 1958-09-26 1961-03-14 Gen Electric Transformer

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4106089A (en) * 1976-09-10 1978-08-08 The Garrett Corporation Alternating current power dividing or combining system
US4471231A (en) * 1982-05-27 1984-09-11 Kabushiki Kaisha Komatsu Seisakusho Alternating current feeder system for trolley-assisted dump trucks
US4493016A (en) * 1982-10-07 1985-01-08 Westinghouse Electric Corp. Rectifier transformer
US4513243A (en) * 1983-06-08 1985-04-23 Westinghouse Electric Corp. Core form transformer for selective cancellation of subsynchronous resonance
US4638177A (en) * 1985-11-14 1987-01-20 Westinghouse Electric Corp. Rotating flux transformer
US4639610A (en) * 1985-12-10 1987-01-27 Westinghouse Electric Corp. Rotating flux transformer
US4833583A (en) * 1987-01-23 1989-05-23 Trailigaz-Compagnie Generale De L'ozone Electric supply device for an ozonizer
US5063487A (en) * 1990-03-22 1991-11-05 The United States Of America As Represented By The Secrectary Of The Navy Main and auxiliary transformer rectifier system for minimizing line harmonics
US5206539A (en) * 1991-11-15 1993-04-27 Power Distribution, Inc. Transformer with cancellation of harmonic currents by phase shited secondary windings
US5343080A (en) * 1991-11-15 1994-08-30 Power Distribution, Inc. Harmonic cancellation system
US5434455A (en) * 1991-11-15 1995-07-18 Power Distribution, Inc. Harmonic cancellation system
US5446642A (en) * 1992-05-11 1995-08-29 Electric Power Research Institute, Inc. Harmonic blocking converter system
US5515264A (en) * 1992-05-11 1996-05-07 Electric Power Research Institute, Inc. Optimized high power voltage sourced inverter system

Also Published As

Publication number Publication date
FR2074686B1 (enrdf_load_stackoverflow) 1977-06-03
NL7100149A (enrdf_load_stackoverflow) 1971-07-21
DE2102233A1 (enrdf_load_stackoverflow) 1971-08-26
CH538774A (fr) 1973-06-30
FR2074686A1 (enrdf_load_stackoverflow) 1971-10-08
GB1340256A (en) 1973-12-12

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