WO2016089351A1 - Transformateurs de puissance avec capacité de limitation de défaillances - Google Patents

Transformateurs de puissance avec capacité de limitation de défaillances Download PDF

Info

Publication number
WO2016089351A1
WO2016089351A1 PCT/US2014/067917 US2014067917W WO2016089351A1 WO 2016089351 A1 WO2016089351 A1 WO 2016089351A1 US 2014067917 W US2014067917 W US 2014067917W WO 2016089351 A1 WO2016089351 A1 WO 2016089351A1
Authority
WO
WIPO (PCT)
Prior art keywords
current
fault
winding
magnetic core
current source
Prior art date
Application number
PCT/US2014/067917
Other languages
English (en)
Inventor
Yucheng Zhang
Original Assignee
South Dakota Board Of Regents
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 South Dakota Board Of Regents filed Critical South Dakota Board Of Regents
Priority to PCT/US2014/067917 priority Critical patent/WO2016089351A1/fr
Publication of WO2016089351A1 publication Critical patent/WO2016089351A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F30/00—Fixed transformers not covered by group H01F19/00
    • H01F30/06—Fixed transformers not covered by group H01F19/00 characterised by the structure
    • H01F30/12—Two-phase, three-phase or polyphase transformers

Definitions

  • This invention relates generally to devices and systems for protecting electrical systems from fault currents, and more particularly to power transformers with fault- current-limiting capability.
  • FCLs fault current limiters
  • the present invention is directed to a power transformer with the capability to create a virtual air gap in its magnetic core to enable fault-limiting capability within the power transformer itself. This eliminates, or at least significantly reduces, the need for fault-current limiters in series to the upstream/downstream power transformer.
  • the present invention is directed to a power transformer with fault-current-limiting capability.
  • the power transformer has a magnetic core.
  • An input AC winding is wrapped around a first portion of the magnetic core.
  • the input AC winding is adapted for connection to an electric power source.
  • An output AC winding is wrapped around a second portion of the magnetic core.
  • the output AC winding is adapted for connection to a power receiver.
  • a DC current source is electrically connected to a DC winding, which is wrapped to the magnetic core between the first and second portions of the magnetic core, such that application of a current from the DC current source causes magnetic flux linkage weakening within the magnetic core to at least partially magnetically isolate the first AC winding from the second AC winding.
  • a controller is adapted to selectively activate the DC current source when a fault current has been detected.
  • the power transformer with fault-current-limiting may further include a sensor that is adapted to detect the fault current and send a signal to the controller when the fault current has been detected.
  • the sensor may be further adapted to sense when the fault has been cleared and send a signal to the controller when the fault has been cleared.
  • the controller may be adapted to deactivate the DC current source in response to receiving the signal that the fault has been cleared. Activation of the DC current source may create a virtual air gap within the magnetic core.
  • the DC current source may be a low- voltage, high-current power source.
  • the present invention is directed to a method of limiting fault currents in a power transformer.
  • a power transformer is provided that has a magnetic core, wherein an input AC winding is wrapped around a first portion of the magnetic core and an output AC winding is wrapped around a second portion of the magnetic core.
  • a DC current source is connected to a DC winding, which is wrapped to the magnetic core between the first portion and the second portion.
  • the input AC winding is connected to an AC power source.
  • the output AC winding is connected to a power receiver. If a fault current is detected, the DC current source is activated to thereby increase the magnetic reluctance in the magnetic core between the input AC winding and the output AC winding.
  • the step of activating the DC current source may create a virtual air gap in the magnetic core between the input AC winding and the output AC winding.
  • the method may further include detecting when the fault has been cleared and deactivating the DC current source to eliminate the virtual air gap in the magnetic core.
  • Figure 2 is a schematic showing a magnetic core of the power transformer of Figure 1 in a normal operation mode.
  • Figure 3 is a schematic showing the magnetic core of the power transformer of Figure 1 in a fault-current-limiting mode.
  • Figure 4 is a flow chart illustrating steps for a method of limiting fault currents in a power transformer according to one embodiment of the present invention.
  • FIG. 1 shows an electrical power distribution network 100 that includes a fault- current-limiting power transformer 10 according to one embodiment of the present invention.
  • the power distribution network 100 includes an electrical power source 12 that provides an input electrical power to the power transformer 10 and an electrical power receiver 14 that receives an output AC electrical power from the power transformer 10.
  • the power source 12 may be a high voltage power line that is part of a transmission network of an electrical power grid and the transformer 10 may be used to step-down the voltage for the electrical power receiver 14, which could be the electrical distribution network for a local area/community or other type of electrical distribution system, such as a micro grid.
  • the power transformer 10 could be used to step-up the voltage from the power source 12 for high voltage transmission networks.
  • the power source 12 might be a power generation plant, e.g. conventional AC generators and emerging renewable energy resources, and the electrical power receiver 14 could be the high voltage lines.
  • the fault-current-limiting power transformer 10 of the present invention will have use in a wide variety of power transmission and distribution settings.
  • FIG. 2 A schematic representing one embodiment of a fault-current-limiting power transformer 10 according to the present invention is shown in Figure 2.
  • the power transformer 10 includes a magnetic core 16. Alternating current (AC) input windings 18 are wrapped around a first portion 20 of the magnetic core 16. The input windings 18 are connected to the electrical power source 12, which provides the power to cause an alternating current 19 to flow through the input windings 18.
  • the input current 19 within the input windings 18 creates a magnetic flux (represented by dashed lines) 22 within the core 16.
  • This magnetic flux 22 in turn induces an output voltage 21 within output windings 24 that are wrapped around a second portion 26 of the magnetic core 16.
  • the induced output current 21 supplies electrical power to the power receiver 14.
  • a direct current (DC) current source 28 is connected to the magnetic core 16 via DC windings 30.
  • the DC current source 28 may be a low-voltage, high-current DC source. In the normal state when there is no fault current condition, the DC current source 28 is not activated and no DC current flows from the DC current source 28 to the DC windings 30.
  • a controller 32 is connected to the DC current source 28 to selectively activate and deactivate the DC current source 28.
  • a current sensor 34 is associated with the system to detect current, which flows through the transformer 10.
  • the current sensor 34 When a current is detected by the current sensor 34, the current sensor 34 sends a current signal to the controller 32.
  • the controller 32 analyzes the current level and identifies whether there is a fault condition or not. If the current level exceeds a threshold defined by power engineer, the controller 32 identifies there is a fault and activates the DC current source 28. This signal causes the controller 32 to activate the DC current source 28.
  • Figure 3 shows the power transformer 10 after the DC current source 28 has been activated in response to a sensed fault current. In that instance a DC current 34 flows through the DC windings 30. This DC current at least partially weakens the magnetic flux 22 within the magnetic core 16, which eliminates, or at least greatly reduces, the induced voltage 21 in the output windings 24.
  • the DC windings 30 and the DC current source 28 are adapted to create a virtual air gap 38 in the magnetic core 16.
  • the virtual air gap 38 magnetically isolates, at least partially, the output windings 24 from the input windings 18.
  • the virtual air gap 38 is a saturated portion of the magnetic core 16 that increases the reluctance of the magnetic core 16.
  • the level of reluctance can be controlled by the level of DC current 36 supplied to the DC windings 30 by the DC current source 28.
  • the controller 32 will identify that the fault condition has cleared.
  • the controller turns off the DC current source 28, such that the virtual air gap 38 dissipates, and the magnetic core 16 returns to its natural reluctance such that full magnetic flux 22 again flows through the magnetic core 16 between the input AC windings 18 and the output AC windings 24 as shown in Figure 2.
  • magnetic core 16 is shown as a standard configuration, it should be appreciated that other shapes may be useful and beneficial in creating the desired virtual air gap.
  • the virtual air gap 38 may be activated and deactivated rapidly in response to the presence and dissipation of a fault current. Accordingly, it may be possible to isolate unfaulted zones of a power grid from the fault current in no more than 0.5 cycles (8.3 ms in a 60 Hz system). This represents a significant improvement over state-of-the-art systems which typically require at least 2.5 cycles (41.7 ms at 60 Hz).
  • the present invention also relates to a method for protecting electrical equipment from fault currents using the fault-current-limiting transformer 10.
  • This method is illustrated in Figure 4.
  • a power transformer 10 having a magnetic core 16 is provided, wherein an input AC winding 18 is wrapped around a first portion 20 of the magnetic core 16 and an output AC winding 24 is wrapped around a second portion 26 of the magnetic core 16.
  • a DC current source 28 is connected to the magnetic core 16 via a DC winding 30 between the first portion 20 and the second portion 26.
  • the input AC windings 18 are connected to an AC power source 12, and the output AC windings are connected to a AC power receiver 12.
  • the DC current source 28 When a fault current is detected, the DC current source 28 is activated to create a virtual air gap 38 in the magnetic core 16 via the DC winding 30 between the input AC winding 18 and the output AC winding 24. Once the fault has been cleared, the DC current source is deactivated to remove the virtual air gap 38.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Emergency Protection Circuit Devices (AREA)

Abstract

L'invention concerne un transformateur de puissance doté d'une capacité de limitation du courant de défaut. Un noyau magnétique dans le transformateur de puissance comprend des enroulements CA d'entrée et des enroulements CA de sortie. Une source de courant continu est raccordée au noyau magnétique par l'intermédiaire d'un enroulement CC entre les enroulements CA d'entrée et les enroulements CA de sortie. La source de courant continu est activée en réponse à un courant de défaut pour créer un entrefer virtuel à l'intérieur du noyau magnétique. Lorsque le défaut est supprimé, la source de courant continu est désactivée pour éliminer l'entrefer virtuel.
PCT/US2014/067917 2014-12-01 2014-12-01 Transformateurs de puissance avec capacité de limitation de défaillances WO2016089351A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/US2014/067917 WO2016089351A1 (fr) 2014-12-01 2014-12-01 Transformateurs de puissance avec capacité de limitation de défaillances

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US2014/067917 WO2016089351A1 (fr) 2014-12-01 2014-12-01 Transformateurs de puissance avec capacité de limitation de défaillances

Publications (1)

Publication Number Publication Date
WO2016089351A1 true WO2016089351A1 (fr) 2016-06-09

Family

ID=56092119

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2014/067917 WO2016089351A1 (fr) 2014-12-01 2014-12-01 Transformateurs de puissance avec capacité de limitation de défaillances

Country Status (1)

Country Link
WO (1) WO2016089351A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018023176A1 (fr) 2016-08-05 2018-02-08 Faraday Grid Limited Système et procédé d'alimentation électrique
CN109075717A (zh) * 2016-09-14 2018-12-21 法拉达伊格里德有限公司 配电网络和过程

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060158803A1 (en) * 2003-01-27 2006-07-20 Bar Ilan University Fault current limiters (fcl) with the cores staurated by superconducting coils
US20090147412A1 (en) * 2007-12-07 2009-06-11 Cooper Technologies Company Transformer inrush current detector
US20120026637A1 (en) * 2010-03-12 2012-02-02 Francis Anthony Darmann Fault Current Limiter
US20120154966A1 (en) * 2009-08-31 2012-06-21 Ricor Cryogenic & Vacuum Systems Limited Partnership Fault current limiters (fcl) with the cores saturated by non-superconducting coils
WO2012167331A1 (fr) * 2011-06-10 2012-12-13 Zenergy Power Pty Ltd Limiteur de courant de défaut
US20130320940A1 (en) * 2011-02-25 2013-12-05 Ut-Battelle, Llc Power flow control using distributed saturable reactors

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060158803A1 (en) * 2003-01-27 2006-07-20 Bar Ilan University Fault current limiters (fcl) with the cores staurated by superconducting coils
US20090147412A1 (en) * 2007-12-07 2009-06-11 Cooper Technologies Company Transformer inrush current detector
US20120154966A1 (en) * 2009-08-31 2012-06-21 Ricor Cryogenic & Vacuum Systems Limited Partnership Fault current limiters (fcl) with the cores saturated by non-superconducting coils
US20120026637A1 (en) * 2010-03-12 2012-02-02 Francis Anthony Darmann Fault Current Limiter
US20130320940A1 (en) * 2011-02-25 2013-12-05 Ut-Battelle, Llc Power flow control using distributed saturable reactors
WO2012167331A1 (fr) * 2011-06-10 2012-12-13 Zenergy Power Pty Ltd Limiteur de courant de défaut

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018023176A1 (fr) 2016-08-05 2018-02-08 Faraday Grid Limited Système et procédé d'alimentation électrique
CN109074108A (zh) * 2016-08-05 2018-12-21 法拉达伊格里德有限公司 电力供应系统及过程
CN110121684A (zh) * 2016-08-05 2019-08-13 法拉达伊格里德有限公司 电力供应系统及过程
JP2019525710A (ja) * 2016-08-05 2019-09-05 ファラデー グリッド リミテッドＦａｒａｄａｙ Ｇｒｉｄ Ｌｉｍｉｔｅｄ 電力供給システムおよび方法
EP3494451A4 (fr) * 2016-08-05 2020-04-29 Faraday Grid Limited Système et procédé d'alimentation électrique
EP3494450A4 (fr) * 2016-08-05 2020-04-29 Faraday Grid Limited Système et procédé d'alimentation électrique
JP7036513B2 (ja) 2016-08-05 2022-03-15 サード イクエーション リミテッド 電力供給システムおよび方法
CN109075717A (zh) * 2016-09-14 2018-12-21 法拉达伊格里德有限公司 配电网络和过程

Similar Documents

Publication Publication Date Title
EP2602893B1 (fr) Protection de système d'alimentation
US10928794B2 (en) Fault detection systems and methods for power grid systems
US10569895B2 (en) Systems, methods, and devices for bipolar high voltage direct current ground fault detection
CN103792459A (zh) 用于测试电子跳闸装置的方法和设备
JP6554109B2 (ja) 配電系統用の電力系統接続点、電力系統接続点用の調整変圧器、及び電力系統接続点を操作するための方法
CN202259980U (zh) 一种有地线带电保护机构的插头
JP2011063431A (ja) エレベータの安全回路
EP3084800B1 (fr) Appareil de commutation électrique comprenant un circuit de déclenchement électronique à courant alternatif ayant un circuit de détection de défaut d'arc et une alimentation électrique
WO2021076323A1 (fr) Module de puissance fiable pour améliorer la disponibilité d'un dispositif de sous-station
EP2879152B1 (fr) Détecteur de soudage de relais, équipement de relais l'incorporant et procédé de détection de soudage
KR20130047703A (ko) 배전계통의 결상 시 결상복구기 및 그 복구방법
JP2019009977A (ja) 保護ユニットの動作を試験する装置および方法、ならびにそのような試験装置を備える保護ユニット
WO2016089351A1 (fr) Transformateurs de puissance avec capacité de limitation de défaillances
KR102058400B1 (ko) 전력계통의 선로에서 순시전류 판별장치
CN204012649U (zh) 可调灵敏度的漏电保护器
KR101634633B1 (ko) 지락 과전류 계전기 및 그것의 작동 방법
CN102255299B (zh) 一种双馈风力发电机变流器主动式保护方法及装置
Zubieta et al. Protection scheme for a residential DC microgrid
JP2012143076A (ja) 風力発電システムの制御方法及び制御装置
CN102243287A (zh) 磁浮定子线圈发生多点接地故障的监测方法
JPH11299082A (ja) 過電圧保護機能付き漏電遮断装置
CN211790736U (zh) 一种独立电源脱扣的漏电保护器电路
KR101437568B1 (ko) 선택 스위치를 갖는 누전 차단기
CN202564702U (zh) 有地线带电保护机构的插头
JP2007068279A (ja) 地絡事故の検出方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 14907431

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 14907431

Country of ref document: EP

Kind code of ref document: A1