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WO1997034210A1 - Bobine de reactance reglable avec enroulement de commande de retroaction - Google Patents

Bobine de reactance reglable avec enroulement de commande de retroaction Download PDF

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Publication number
WO1997034210A1
WO1997034210A1 PCT/SE1997/000424 SE9700424W WO9734210A1 WO 1997034210 A1 WO1997034210 A1 WO 1997034210A1 SE 9700424 W SE9700424 W SE 9700424W WO 9734210 A1 WO9734210 A1 WO 9734210A1
Authority
WO
WIPO (PCT)
Prior art keywords
control
voltage
current
winding
load
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.)
Ceased
Application number
PCT/SE1997/000424
Other languages
English (en)
Inventor
Sven HÖRNFELDT
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ABB Research Ltd Switzerland
ABB Research Ltd Sweden
Original Assignee
ABB Research Ltd Switzerland
ABB Research Ltd Sweden
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by ABB Research Ltd Switzerland, ABB Research Ltd Sweden filed Critical ABB Research Ltd Switzerland
Publication of WO1997034210A1 publication Critical patent/WO1997034210A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
    • G05F1/00—Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
    • G05F1/10—Regulating voltage or current 
    • G05F1/12—Regulating voltage or current  wherein the variable actually regulated by the final control device is AC
    • G05F1/32—Regulating voltage or current  wherein the variable actually regulated by the final control device is AC using magnetic devices having a controllable degree of saturation as final control devices
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
    • H02H9/02—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess current
    • H02H9/021—Current limitation using saturable reactors

Definitions

  • the present invention relates to a device comprising a controllable reactor by means of which the voltage, phase, current, harmonic content, etc., of an ac network may be influenced.
  • the controllable reactor comprises a power winding and a control winding which surround the same magnetic flux.
  • the device also.comprises a control and supply circuit for the control winding.
  • Voltage control The voltage is to be adjustable upwards or downwards, or the voltage is to be kept constant during varying loads;
  • the current is to be limited when exceeding a predetermined value
  • Harmonic filtering Currents with a frequency different from the fundamental of the alternating voltage, also current pulses, are to be damped.
  • the rotary transformer which serves as a simple, robust and practically stepless voltage control for low voltage, is no alternative for voltage control of power transformers.
  • a voltage control is achieved with on-load tap changers which make it possible to choose between a number of terminals of the control winding of the trans ⁇ former.
  • On-load tap changers are mechanically complicated designs and cause a large part of the transformer breakdowns.
  • Harmonic filtering may be performed with permanently installed filter circuits, or with stepwise connection or disconnection of filter elements in the same way as described above for power factor correction. Also active filtering with feedback and use of power electronics occurs within some special fields of use.
  • Current limiting is carried out either by directly breaking the current, for example with a circuit breaker, or by placing a device in the circuit, which functions as a variable impe- dance, for example an inductance which may be changed by changed premagnetization of the core.
  • a device solves the problem of carrying out, in a stepless manner, voltage control, power factor correction, harmonic filtering and current limiting using one and the same piece of equipment.
  • a device according to the invention will normally be used in connection with a network, the line voltage Uo of which is to be supplemented with a control voltage ⁇ U before it reaches to a load which places high demands on the feeding voltage, referred to below as load voltage U.
  • the load is a network comprising a number of load objects.
  • a device For each phase of the network, a device according to the invention comprises at least one control winding and at least one power winding with a common magnetic flux ⁇ which is measured with a transducer, preferably a measuring coil surrounding the same magnetic flux.
  • the current In through the power winding and the load referred to below as a load current
  • the line voltage Uo, the load voltage U and the voltage across the power winding which constitutes the above- mentioned control voltage ⁇ U are measured with the aid of suitable measuring means and are supplied to a control unit together with a signal corresponding to the magnetic flux, for example the voltage of the measuring coil, referred to below as the flux voltage V ⁇ .
  • the control unit controls a power amplifier which supplies the control winding with a control current I s .
  • the relationship between the measured values Io, ⁇ U, Uo, U, V ⁇ and the control current is determined by the desired function of the device.
  • control winding may instead be sectioned with one power amplifier for each section and a common control unit for all the power amplifiers be used.
  • the power amplifier delivers a control current which gives rise to a control voltage +/- ⁇ U in the power winding, depending on whether the load voltage is to be increased or decreased.
  • a control voltage ⁇ U is instead achieved which is phase-shifted by +/- ⁇ /2 in relation to the line voltage Uo ⁇
  • a combination of power factor correc ⁇ tion and voltage control means an arbitrary phase angle of the control voltage ⁇ U which can also be expressed as a complex voltage which is added to the line voltage Uo-
  • a control current I s is fed to the control winding which, for a load current Io through the power winding which falls below a predetermined maximum value, results in the magnetic flux ⁇ disappearing.
  • control voltage ⁇ U across the power winding is reduced to the normally negligible resistive voltage drop.
  • This is equivalent to a transformer with a short-circuited superconducting secondary coil which becomes traversed by the secondary current which causes the magnetic flux to disappear.
  • This method is used in the patent 94/01470-1 SE for active damping of magnetic fields. If the load current Io exceeds the maximum value, the control current is no longer increased in a corresponding way but is maintained at a value corresponding to the maximum value. This means that the magnetic flux ⁇ becomes different from zero.
  • a device accor- ding to the invention functions as a reactor which limits this current by achieving an inductive voltage drop across the power winding.
  • the device functions as a current-limiting reactor with a considerable inductance.
  • the control winding is fed with a control current which only contains the fundamental of the line voltage with a current intensity which is so adapted that the fundamental component of the magnetic flux disappears.
  • the load current through the power winding then only "sees" one, in practice negligible, resistive load for the fundamental, but an inductive load for all the harmonics and also other disturbances, for example current pulses.
  • a device according to the invention is thus made to function as a bandpass filter with the fundamental frequency as the centre frequency.
  • the control unit may also be caused to give a con- trol current in opposition to current components through the power winding which do not belong to the fundamental; the device then functions as an active filter.
  • the invention may be regarded as an improvement of a so-called booster transformer, where the galvanic coupling between a winding of an excitation transformer and a winding of a series transformer, which only permits voltage control, is replaced by the control unit and the power amplifier. In this way, the plurality of control functions already described may be achieved.
  • Figure 1 shows a device according to the invention, connected to a network in the form of a power transformer and a load.
  • Figure 2 shows the relationship between uncorrected and corrected voltage in a vector diagram.
  • Figure 3 shows a non-sinusoidal line voltage, the control voltage of the device and a load voltage after filtering.
  • Figures 4a and 4b show schematically combinations of an on ⁇ load tap changer with one or more devices according to the invention.
  • Figure 1 shows a device according to the invention, which is connected between a network in the form of a power transformer 1 and a load 2, symbolized by a resistor.
  • the load 2 may consist of a network comprising a plurality of consumers.
  • the power transformer has a primary winding 3 and a secondary winding 4.
  • the voltage of the secondary winding corresponds to the above-mentioned line voltage Uo.
  • the device comprises an iron core 6 with a power winding 5, a control winding 7 and a measuring winding 8 for deter ⁇ mining the magnetic flux ⁇ in the iron core.
  • the power winding is connected in series with the secondary winding and the load, and a load current Io flows in the circuit.
  • the control winding is fed from a power amplifier 9 which is controlled from a control unit 10.
  • the power amplifier and the control unit are fed with current from a current supply device 11, which in turn is fed from an auxiliary winding 12 of the power transformer 1.
  • a current supply device 11 which in turn is fed from an auxiliary winding 12 of the power transformer 1.
  • the line voltage Uo, the load voltage U, the load current Io and the voltage V ⁇ across the measuring winding which is proportional to a magnetic flux ⁇ common to the power winding and the control winding, are fed back to the control unit.
  • the combinations ⁇ U and Uo or ⁇ U and U may be supplied to the control unit instead of the combination U and UQ, depending on which combination of measurements is simplest to achieve. In that case, it is also necessary for ⁇ U to be measured; this is indicated in dashed lines in Figure 1.
  • the control unit is to be programmed such that, on the basis of the feedback signals and otherwise well-known relationships between these, it achieves, via the power amplifier, the control current I s to the control winding which is needed for the control voltage ⁇ U to become the proper supplementation of the line voltage Uo for the application in question.
  • the application may be voltage control of the load voltage U at varying line voltage and/or load, power factor correction, current limiting, filtering, etc., or some combination thereof.
  • the control voltage corresponds to the amplitude of that control error which is obtained on a comparison between the desired amplitude
  • the relationship between the flux ⁇ for a given ⁇ U and the relationship between the flux ⁇ and the control current I s may be determined.
  • the control unit via the power amplifier, may generate that control current I s which gives a flux propor ⁇ tional to ⁇ U, in phase with or in opposition to the line voltage Uo, in the power winding.
  • the control unit can generate the required control current via the power amplifier in the same way as described above.
  • a frequently occurring control case is that the load voltage U has to be controlled both in amplitude and in phase relative to a line voltage Uo •
  • the task thus comprises, according to Figure 2, determining the ⁇ U, both from the amplitude and the phase point of view, which is needed for the vectorial sum of Uo and ⁇ U to correspond to the desired load voltage U. If the desired load voltage U is phase-shifted by an angle ⁇ relative to the line voltage Uo, the amplitude of ⁇ U is determined according to
  • phase shift ⁇ between ⁇ U and Uo is determined from
  • control unit may generate the required control voltage via the power amplifier, in the same way as described above.
  • a device When a device according to the invention is to function as a current limiter, it is a precondition that, at a load current I ⁇ less than an allowed maximum current I ⁇ ma ⁇ / it shall have as small an influence on the circuit as possible.
  • the control unit is therefore adapted such that, at a load current less than the maximum current, it generates and adapts such a control current I s that the resultant flux from the control winding and the power winding is zero.
  • the control voltage ⁇ U across the power winding will consist of the normally negli- gible resistive voltage drop caused by the relevant load current and the resistance of the power winding.
  • the control unit is adapted to maintain the maximum control current Ismax- Because the load current becomes greater than I ⁇ ma ⁇ / during the transition stage the flux will become different from zero which means that the circuit will have a limited addition of inductance.
  • the device By redu ⁇ cing the control current to zero after the transition stage, which may amount to some twenty or thirty milliseconds, the device will function as a current limiting reactor with a considerable inductance.
  • the reduction of the control current may take place immediately after the load current tends to exceed the maximum current, that is, the above-mentioned transition process is excluded.
  • Figure 3a shows a non-sinusoidal line voltage Uo as a function of time t.
  • the control unit is arranged with a Fourier filter which produces the sinusoidal fundamental component of the line voltage and forms that control voltage ⁇ U, shown in Figure 3b, which corresponds to the difference between the relevant line voltage and its sinusoidal fundamental compo ⁇ nent.
  • control current I s may be generated which, via the power amplifier, gives a flux in the power winding proportional to ⁇ U.
  • control voltage ⁇ U is to correspond to the fundamental component and the amplitude of the line voltage, which may both be extracted from the above- mentioned Fourier filter.
  • control current I s may be generated which, via the power amplifier, gives a flux in the power winding propor ⁇ tional to ⁇ U.
  • Figure 4a and Figure 4b show schematically how at least one device according to the invention may be used for stepless voltage control together with an on-load tap changer of a power transformer or a reactor.
  • the terminals of an on-load tap changer are symbolized by the rings 13.
  • the voltage step between two terminals is ⁇ u.
  • one of the devices is replaced by a direct connec ⁇ tion 17 which is only connected when the device 16 provides the same control voltage ⁇ U as the voltage step ⁇ u between the terminals, such that the point 16 and the upper terminal lie on the same voltage.
  • Contacts may be opened and closed in a voltage-free and hence discharge-free manner
  • the voltage of a power transformer or a reactor may be controlled in a stepless manner
  • the on-load tap changer may be designed with fewer terminals.
  • a device for control of the voltage of the power transformer need only be dimensioned for one voltage step between the terminals.
  • a device according to the invention may be used at the same time for both power factor correction and filtering.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Automation & Control Theory (AREA)
  • Control Of Electrical Variables (AREA)

Abstract

La présente invention concerne un dispositif permettant d'exécuter une ou plusieurs fonctions de commande de tension, de correction de facteur de puissance, de limitation de tension et de filtrage harmonique dans un réseau. Ledit dispositif comporte une tension de secteur U0 et une tension de charge U, mises en oeuvre par une tension de commande ΔU. Le dispositif comporte en outre les éléments suivants: une bobine de réactance réglable constituée d'au moins un enroulement de commande (7) et d'au moins un enroulement de puissance (5) pour la génération de la tension de commande ΔU et une unité de commande (10) qui, à travers au moins un amplificateur (9) de puissance, fournit un courant de commande Is à l'enroulement de commande. L'enroulement de puissance est connecté en série à la charge (2) qui est traversée par un courant de travail I0. Un élément de mesure (8) détecte le flux magnétique (Ζ) de la bobine de réactance réglable et fournit une tension de flux VΖ qui lui est proportionnelle. A l'aide des éléments de mesure, ces signaux qui correspondent à la tension de secteur U0, à la tension de charge U, à la tension de commande ΔU, au courant de travail I0 et à la tension de flux VΖ sont retransmis à l'unité de commande qui, en fonction desdites tensions, via le ou les amplificateurs de puissance, fournit ledit courant de commande Is à l'enroulement de commande que la tension de commande ΔU, induite dans l'enroulement de puissance, ajoute à la tension de secteur U0 pour exécuter la où les fonctions concernées.
PCT/SE1997/000424 1996-03-15 1997-03-13 Bobine de reactance reglable avec enroulement de commande de retroaction Ceased WO1997034210A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE9600988-1 1996-03-15
SE9600988A SE515458C2 (sv) 1996-03-15 1996-03-15 Styrbar reaktor med återkopplad styrlindning

Publications (1)

Publication Number Publication Date
WO1997034210A1 true WO1997034210A1 (fr) 1997-09-18

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PCT/SE1997/000424 Ceased WO1997034210A1 (fr) 1996-03-15 1997-03-13 Bobine de reactance reglable avec enroulement de commande de retroaction

Country Status (2)

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SE (1) SE515458C2 (fr)
WO (1) WO1997034210A1 (fr)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003044612A1 (fr) * 2001-11-21 2003-05-30 Magtech As Appareil a impedance reglable
US6788180B2 (en) 2001-11-21 2004-09-07 Magtech As Controllable transformer
WO2005050341A1 (fr) * 2003-11-19 2005-06-02 Jaroslav Foglar Regulateur de tension avec transformateur reglable
WO2005076293A1 (fr) * 2004-02-03 2005-08-18 Magtech As Dispositifs et procedes de regulation d'une alimentation electrique
US6933822B2 (en) 2000-05-24 2005-08-23 Magtech As Magnetically influenced current or voltage regulator and a magnetically influenced converter
US6965291B2 (en) 2001-11-21 2005-11-15 Magtech As Circuit component and transformer device with controllable impedance and with systems equipped with such devices
US7026905B2 (en) 2000-05-24 2006-04-11 Magtech As Magnetically controlled inductive device
WO2006087402A3 (fr) * 2005-02-15 2006-11-02 Univ Sevilla Procede de reglage en continu du rapport de tensions dans des transformateurs
US7180206B2 (en) 2002-12-12 2007-02-20 Magtech As System for voltage stabilization of power supply lines
EP3413322A1 (fr) * 2017-06-08 2018-12-12 Goodrich Control Systems Inducteur actif

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1513876A1 (de) * 1964-12-23 1969-09-18 Honeywell Inc Spannungsregelgeraet fuer Wechselstromspeisung
US3628057A (en) * 1970-06-19 1971-12-14 Allen Bradley Co Corrective circuit for an active narrow notch filter
WO1987001834A1 (fr) * 1985-09-13 1987-03-26 Hasler Ag Convertisseur de puissance electrique
US4833585A (en) * 1988-08-03 1989-05-23 Westinghouse Electric Corp. Zone filter
US5341281A (en) * 1993-05-14 1994-08-23 Allen-Bradley Company, Inc. Harmonic compensator using low leakage reactance transformer
WO1995003645A1 (fr) * 1993-07-26 1995-02-02 Siemens Aktiengesellschaft Procede de limitation du courant de court-circuit sur une ligne d'alimentation electrique et systeme de limitation du courant de court-circuit

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1513876A1 (de) * 1964-12-23 1969-09-18 Honeywell Inc Spannungsregelgeraet fuer Wechselstromspeisung
US3628057A (en) * 1970-06-19 1971-12-14 Allen Bradley Co Corrective circuit for an active narrow notch filter
WO1987001834A1 (fr) * 1985-09-13 1987-03-26 Hasler Ag Convertisseur de puissance electrique
US4833585A (en) * 1988-08-03 1989-05-23 Westinghouse Electric Corp. Zone filter
US5341281A (en) * 1993-05-14 1994-08-23 Allen-Bradley Company, Inc. Harmonic compensator using low leakage reactance transformer
WO1995003645A1 (fr) * 1993-07-26 1995-02-02 Siemens Aktiengesellschaft Procede de limitation du courant de court-circuit sur une ligne d'alimentation electrique et systeme de limitation du courant de court-circuit

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN, Vol. 13, No. 444, E-828; & JP,A,01 170 328 (NISSIN ELECTRIC CO LTD), 5 July 1989. *

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7256678B2 (en) 2000-05-24 2007-08-14 Magtech As Magnetically controlled inductive device
US7193495B2 (en) 2000-05-24 2007-03-20 Espen Haugs Magnetically influenced current or voltage regulator and a magnetically influenced converter
US7026905B2 (en) 2000-05-24 2006-04-11 Magtech As Magnetically controlled inductive device
US6933822B2 (en) 2000-05-24 2005-08-23 Magtech As Magnetically influenced current or voltage regulator and a magnetically influenced converter
US6965291B2 (en) 2001-11-21 2005-11-15 Magtech As Circuit component and transformer device with controllable impedance and with systems equipped with such devices
US6788180B2 (en) 2001-11-21 2004-09-07 Magtech As Controllable transformer
US7061356B2 (en) 2001-11-21 2006-06-13 Magtech As Controllable transformer
WO2003044612A1 (fr) * 2001-11-21 2003-05-30 Magtech As Appareil a impedance reglable
CN100397277C (zh) * 2001-11-21 2008-06-25 马格技术公司 具有可控制阻抗的器件
US7180206B2 (en) 2002-12-12 2007-02-20 Magtech As System for voltage stabilization of power supply lines
WO2005050341A1 (fr) * 2003-11-19 2005-06-02 Jaroslav Foglar Regulateur de tension avec transformateur reglable
WO2005076293A1 (fr) * 2004-02-03 2005-08-18 Magtech As Dispositifs et procedes de regulation d'une alimentation electrique
WO2006087402A3 (fr) * 2005-02-15 2006-11-02 Univ Sevilla Procede de reglage en continu du rapport de tensions dans des transformateurs
ES2277500A1 (es) * 2005-02-15 2007-07-01 Universidad De Sevilla Procedimiento de regulacion continua de la relacion de tensiones en transformadores.
ES2277500B1 (es) * 2005-02-15 2008-06-16 Universidad De Sevilla Procedimiento de regulacion continua de la relacion de tensiones en transformadores.
EP3413322A1 (fr) * 2017-06-08 2018-12-12 Goodrich Control Systems Inducteur actif

Also Published As

Publication number Publication date
SE9600988L (sv) 1997-09-16
SE515458C2 (sv) 2001-08-06
SE9600988D0 (sv) 1996-03-15

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