CN106921157A - A kind of AC singlephase earth fault control method of flexible ring net controller - Google Patents

A kind of AC singlephase earth fault control method of flexible ring net controller Download PDF

Info

Publication number
CN106921157A
CN106921157A CN201511001470.0A CN201511001470A CN106921157A CN 106921157 A CN106921157 A CN 106921157A CN 201511001470 A CN201511001470 A CN 201511001470A CN 106921157 A CN106921157 A CN 106921157A
Authority
CN
China
Prior art keywords
phase
voltage
converter
earth fault
alternating current
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.)
Granted
Application number
CN201511001470.0A
Other languages
Chinese (zh)
Other versions
CN106921157B (en
Inventor
阳岳希
高凯
庞辉
李强
邵宝珠
别晓玉
马巍巍
李胜辉
李洪志
许韦华
张潇桐
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.)
State Grid Corp of China SGCC
Electric Power Research Institute of State Grid Liaoning Electric Power Co Ltd
Smart Grid Research Institute of SGCC
Original Assignee
State Grid Corp of China SGCC
Electric Power Research Institute of State Grid Liaoning Electric Power Co Ltd
Smart Grid Research Institute of SGCC
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 State Grid Corp of China SGCC, Electric Power Research Institute of State Grid Liaoning Electric Power Co Ltd, Smart Grid Research Institute of SGCC filed Critical State Grid Corp of China SGCC
Priority to CN201511001470.0A priority Critical patent/CN106921157B/en
Publication of CN106921157A publication Critical patent/CN106921157A/en
Application granted granted Critical
Publication of CN106921157B publication Critical patent/CN106921157B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

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
    • 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
    • H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
    • 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
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]

Landscapes

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

Abstract

The invention provides a kind of AC singlephase earth fault control method of flexible ring net controller, including step 1：The three-phase voltage of real-time detection AC system；Step 2：Judge whether AC system occurs singlephase earth fault；Step 3：Obtain the maximum of the voltage peak of non-faulting phase；Step 4：Redefine the DC voltage command value of AC system；Step 5：Start negative-sequence current control and zero-sequence current control；Step 6：Judge whether singlephase earth fault is removed, DC voltage command value when DC voltage command value is recovered to AC system normally to run will be stated if removing.Compared with prior art, a kind of AC singlephase earth fault control method of flexible ring net controller that the present invention is provided, during it there is singlephase earth fault in AC, DC voltage is reduced in short-term, using the negative voltage fan-out capability for mixing sub-modular structure, alternating current is remained in that the sinusoidal waveform of three-phase symmetrical, improve the reliability of flexible ring net controller.

Description

Alternating-current side single-phase earth fault control method of flexible ring network controller
Technical Field
The invention relates to the technical field of power electronics, in particular to a method for controlling a single-phase earth fault at an alternating current side of a flexible ring network controller.
Background
With the continuous increase of transmission load, the development of power grid is established, and the electromagnetic ring network is continuously formed. The existing general method for disconnecting the electromagnetic ring network is to add an alternating current breaker at a disconnecting point or implement the partitioned operation of the power grid, but the precondition of the method is that the power grid has the basic condition of the open-loop operation. When the electromagnetic ring network is difficult to operate in an open loop mode and meets the condition of safety constraint, technologies such as a unified power flow controller, a phase shifter, an interphase power controller, a controllable series compensation and the like can be adopted, and voltage phase angles are adjusted through an FACTS device, so that circulation currents in the electromagnetic ring network are eliminated, short-circuit currents are limited, power distribution between high/low voltage networks is optimized, and the operation reliability and economy of a system are improved. The flexible ring network controller is back-to-back flexible direct current, and can realize the rapid independent control of active power and reactive power; when the alternating current system breaks down, the flexible direct current does not provide short-circuit current, the fault can be isolated rapidly, and the device has a black start function, and provides a choice for solving the problem of the electromagnetic looped network.
However, when the converter-less transformer is adopted to construct the flexible ring network controller system scheme of the converter based on the hybrid submodule, when the alternating current system has a ground short circuit fault, the fault voltage can directly act on the converter due to the fact that the converter transformer is not isolated, so that large fault voltage stress and current stress are caused, and equipment damage is easily caused. Therefore, it is necessary to provide a fault control method capable of reducing the dc voltage for a short time during a single-phase ground fault on the ac side, and preventing the fault from being transmitted to the other ac system.
Disclosure of Invention
In order to meet the needs of the prior art, the present invention provides a method for controlling an ac-side single-phase ground fault of a flexible looped network controller.
The technical scheme of the invention is as follows:
the method comprises the following steps:
step 1: detecting the three-phase voltage of an alternating current system in real time;
step 2: judging whether the alternating current system has a single-phase earth fault;
and step 3: obtaining the maximum value U of the voltage peak value of a non-fault phase after the single-phase earth fault of the alternating current system occurss_max；
And 4, step 4: redetermining direct-current voltage command value U 'of alternating-current system'd；
And 5: starting negative sequence current control and zero sequence current control;
step 6: judging whether the single-phase earth fault is cleared or not, and if so, judging that the direct-current voltage instruction value U'dRestoring the direct current voltage instruction value U to the normal operation of the alternating current systemd。
Preferably, in step 2, when the voltage of one phase of the ac system is reduced to 0 and the voltages of the other two phases are rapidly increased, a single-phase ground fault occurs in the ac system.
Preferably, the DC voltage command value U 'in step 4'dThe value range is as follows: u'd＜3Ud-2Us_max；
Wherein, UdThe direct current voltage instruction value is the direct current voltage instruction value when the alternating current system normally operates.
Preferably, the topology of the flexible ring network controller comprises a first converter and a second converter; the first converter and the second converter are both directly connected to an alternating current system;
each phase of half-bridge arm of the first converter is formed by connecting a full-bridge sub-module and at least one half-bridge sub-module in series;
each phase half bridge arm of the second converter is also formed by connecting a full-bridge submodule and at least one half-bridge submodule in series.
Compared with the closest prior art, the excellent effects of the invention are as follows:
1. the alternating-current side single-phase earth fault control method of the flexible ring network controller can completely inhibit overvoltage and overcurrent at the alternating-current side, prevent a current converter from bearing overhigh fault voltage and current, and improve the service life of equipment and the reliability of a system;
2. according to the alternating current side single-phase earth fault control method of the flexible ring network controller, the fluctuation of direct current voltage does not exceed +/-1%, the fluctuation of direct current is suppressed within +/-20%, and power electronic devices in a converter can be prevented from being damaged due to overcurrent;
3. according to the alternating current side single-phase earth fault control method of the flexible ring network controller, during the period that the single-phase earth fault occurs on the alternating current side, the direct current voltage is reduced for a short time, the negative voltage output capability of the hybrid submodule structure is utilized, the alternating current output by the converter station still keeps a three-phase symmetrical sine waveform, the fault component can be restrained, the fault is prevented from being transmitted to an alternating current system on the other side, and the reliability of the flexible ring network controller is improved.
Drawings
The invention is further described below with reference to the accompanying drawings.
FIG. 1: the topological structure schematic diagram of the flexible ring network controller in the embodiment of the invention;
FIG. 2: the response oscillogram of the half-bridge submodule in the normal operation of the alternating current system in the embodiment of the invention;
FIG. 3: the response waveform diagram of the half-bridge submodule in the embodiment of the invention when the single-phase earth fault occurs in the alternating current system;
FIG. 4: in the embodiment of the invention, the response oscillogram of the mixing submodule during the normal operation of the alternating current system is shown;
FIG. 5: the response oscillogram of the hybrid submodule in the embodiment of the invention when the single-phase earth fault occurs in the alternating-current system;
FIG. 6: the invention discloses a flow chart of an alternating-current side single-phase earth fault control method of a flexible ring network controller;
FIG. 7: the embodiment of the invention provides an alternating voltage oscillogram during fault-free control;
FIG. 8: the embodiment of the invention provides an alternating current oscillogram during fault-free control;
FIG. 9: the direct-current voltage oscillogram during the fault-free control in the embodiment of the invention;
FIG. 10: in the embodiment of the invention, a direct current waveform diagram is used during fault-free control;
FIG. 11: in the embodiment of the invention, an alternating voltage oscillogram during fault control is added;
FIG. 12: in the embodiment of the invention, an alternating current waveform diagram during fault control is added;
FIG. 13: in the embodiment of the invention, a direct-current voltage oscillogram during fault control is added;
FIG. 14: in the embodiment of the invention, a direct current waveform diagram during fault control is added.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
An embodiment of a method for controlling a single-phase ground fault on an ac side of a flexible ring network controller according to the present invention is shown in fig. 6, and specifically includes:
1. and detecting the three-phase voltage of the alternating current system in real time.
2. And judging whether the alternating current system has single-phase earth fault.
In this embodiment, when it is detected that the voltage of one phase of the ac system is reduced to 0 and the voltages of the other two phases are rapidly increased, a single-phase ground fault occurs in the ac system.
3. Obtaining the maximum value U of the voltage peak value of a non-fault phase after a single-phase earth fault occurs in an alternating-current systems_max。
4. Redetermining DC voltage command value U 'of AC system'd。
DC Voltage instruction value U 'in this embodiment'dThe value range is as follows: u'd＜3Ud-2Us_max；
Wherein, UdThe direct current voltage instruction value is the direct current voltage instruction value when the alternating current system normally operates.
5. And starting negative sequence current control and zero sequence current control.
6. Judging whether the single-phase earth fault is cleared or not, and if so, obtaining a direct-current voltage instruction value U'dRestoring the direct current voltage instruction value U to the normal operation of the alternating current systemd。
The topological structure of the flexible ring network controller adopting the alternating-current side single-phase ground fault control method is shown in fig. 1, and comprises a first converter and a second converter; and the first converter and the second converter are directly connected to an alternating current system. Wherein,
each phase of half bridge arm of the first current converter is formed by connecting a full bridge submodule and at least one half bridge submodule in series, and each phase of half bridge arm of the second current converter is formed by connecting a full bridge submodule and at least one half bridge submodule in series. That is, in this embodiment, the first converter and the second converter are both converters formed by hybrid submodules.
In the embodiment, the response waveform diagrams of the half-bridge sub-module and the hybrid sub-module in normal operation of the alternating current system are respectively shown in fig. 2 and 4, and the response waveform diagrams of the half-bridge sub-module and the hybrid sub-module in single-phase ground fault of the alternating current system are respectively shown in fig. 3 and 5.
In this embodiment, when the ac-side single-phase ground fault control method is not adopted, the ac voltage waveform, the ac current waveform, the dc voltage waveform, and the dc current waveform of the flexible ring network controller are respectively shown in fig. 7, 8, 9, and 10; the ac voltage waveform, the ac current waveform, the dc voltage waveform and the dc current waveform of the flexible ring network controller after the ac side single-phase ground fault control method are shown in fig. 11, 12, 13 and 14, respectively.
As can be seen from fig. 7 to 14, when the control method is not used, overvoltage and overcurrent of about 1.35 times are generated on the ac side after a fault occurs, and when the control method is used, overvoltage and overcurrent on the ac side can be completely suppressed, so that the inverter is prevented from being subjected to excessive fault voltage and current, and the service life of the equipment and the reliability of the system are improved. Meanwhile, when the control method is not adopted, the common mode oscillation fluctuation generated by the direct current voltage after the fault occurs is about +/-20%, the fluctuation generated by the direct current is about +/-130%, the fluctuation of the direct current voltage after the control method is adopted does not exceed +/-1%, the fluctuation of the direct current is restrained within +/-20%, and the power electronic devices in the converter can be prevented from being damaged due to overcurrent.
Finally, it should be noted that: the described embodiments are only some embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Claims (4)

1. An alternating-current side single-phase ground fault control method of a flexible ring network controller, the method comprising:
step 1: detecting the three-phase voltage of an alternating current system in real time;
step 2: judging whether the alternating current system has a single-phase earth fault;
and step 3: obtaining the maximum value U of the voltage peak value of a non-fault phase after the single-phase earth fault of the alternating current system occurss_max；
And 4, step 4: redetermining DC voltage fingers for the AC systemLine value of U'd；
And 5: starting negative sequence current control and zero sequence current control;
step 6: judging whether the single-phase earth fault is cleared or not, and if so, judging that the direct-current voltage instruction value U'dRestoring the direct current voltage instruction value U to the normal operation of the alternating current systemd。
2. The ac-side single-phase ground fault control method for the flexible looped network controller according to claim 1, wherein in step 2, when a voltage of one phase of the ac system drops to 0 and voltages of the other two phases rise rapidly, a single-phase ground fault occurs in the ac system.
3. The method as claimed in claim 1, wherein in step 4, the dc voltage command value U 'is provided'dThe value range is as follows: u'd＜3Ud-2Us_max；
Wherein, UdThe direct current voltage instruction value is the direct current voltage instruction value when the alternating current system normally operates.
4. The ac-side single-phase ground fault control method of the flexible ring network controller according to claim 1, wherein the topology of the flexible ring network controller includes a first converter and a second converter; the first converter and the second converter are both directly connected to an alternating current system;
each phase of half-bridge arm of the first converter is formed by connecting a full-bridge sub-module and at least one half-bridge sub-module in series;
each phase half bridge arm of the second converter is also formed by connecting a full-bridge submodule and at least one half-bridge submodule in series.
CN201511001470.0A 2015-12-28 2015-12-28 Alternating-current side single-phase earth fault control method of flexible ring network controller Active CN106921157B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201511001470.0A CN106921157B (en) 2015-12-28 2015-12-28 Alternating-current side single-phase earth fault control method of flexible ring network controller

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201511001470.0A CN106921157B (en) 2015-12-28 2015-12-28 Alternating-current side single-phase earth fault control method of flexible ring network controller

Publications (2)

Publication Number Publication Date
CN106921157A true CN106921157A (en) 2017-07-04
CN106921157B CN106921157B (en) 2020-08-04

Family

ID=59456201

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201511001470.0A Active CN106921157B (en) 2015-12-28 2015-12-28 Alternating-current side single-phase earth fault control method of flexible ring network controller

Country Status (1)

Country Link
CN (1) CN106921157B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115825539A (en) * 2022-10-17 2023-03-21 盛东如东海上风力发电有限责任公司 Voltage and current determination method and system for wind power grid-connected two-phase ground fault

Citations (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SU801185A1 (en) * 1979-04-24 1981-01-30 Челябинский Политехнический Институтим. Ленинского Комсомола Method of restoring normal operating mode of electric network
US6670793B1 (en) * 2000-04-25 2003-12-30 Sp Systems Pte Ltd Dynamic series voltage compensator and method thereof
US20060142964A1 (en) * 2001-11-23 2006-06-29 Abb Ab Fault location using measurements from two ends of a line
US20060259254A1 (en) * 2000-02-29 2006-11-16 Swarztrauber Sayre A System and method for on-line monitoring and billing of power consumption
US20100001587A1 (en) * 2008-07-01 2010-01-07 Satcon Technology Corporation Photovoltaic dc/dc micro-converter
US20120205981A1 (en) * 2009-09-15 2012-08-16 The University Of Western Ontario Utilization of distributed generator inverters as statcom
CN103326548A (en) * 2013-06-25 2013-09-25 广东电网公司电力科学研究院 Method and system for capacitor voltage control of unified power quality controller
CN103427425A (en) * 2013-08-22 2013-12-04 华北电力大学 Coordinated control device and method for MMC (modular multilevel converter) type unified power quality conditioner
CN103701145A (en) * 2014-01-02 2014-04-02 浙江大学 Mixed MMC-based mixed direct current power transmission system
CN103715693A (en) * 2013-11-11 2014-04-09 国家电网公司 Voltage compensation and fault current limiting hybrid system and control method thereof
CN203942283U (en) * 2014-06-13 2014-11-12 华南理工大学 A kind of three-phase steady state voltage quality control apparatus
CN204118714U (en) * 2014-06-21 2015-01-21 中国能源建设集团广东省电力设计研究院 The alternating current-direct current mating protection device of flexible direct current transmission converter station circuit breaker
CN104505841A (en) * 2014-12-03 2015-04-08 许继电气股份有限公司 Static synchronous power generator reactive support control method for power grid asymmetric short circuit fault
CN104753079A (en) * 2015-03-27 2015-07-01 国家电网公司 Mixed direct-current transmission system capable of implementing inverse power output
CN104811067A (en) * 2015-04-30 2015-07-29 山东大学 PR (proportional resonant) controller-based NMC-HVDC (modular multilevel converter-high voltage direct current) circulating current suppression method
CN104953568A (en) * 2015-07-17 2015-09-30 河南行知专利服务有限公司 Fault protection method for flexible DC power transmission system
CN104993713A (en) * 2015-07-22 2015-10-21 太原理工大学 Control method for double PWM solid-state transformer
US20150318796A1 (en) * 2011-05-08 2015-11-05 Paul Wilkinson Dent Inverter inrush current limiting
CN105098833A (en) * 2015-08-12 2015-11-25 国网山东省电力公司电力科学研究院 Asynchronous constant speed wind turbine system for micro grid and working method thereof
CN105119509A (en) * 2015-07-23 2015-12-02 上海电力设计院有限公司 MMC direct circular current inhibition method suitable for asymmetric AC power grid
CN105207203A (en) * 2015-09-15 2015-12-30 国家电网公司 High-voltage shunt reactor compensation method for typical ultrahigh voltage transmission line

Patent Citations (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SU801185A1 (en) * 1979-04-24 1981-01-30 Челябинский Политехнический Институтим. Ленинского Комсомола Method of restoring normal operating mode of electric network
US20060259254A1 (en) * 2000-02-29 2006-11-16 Swarztrauber Sayre A System and method for on-line monitoring and billing of power consumption
US6670793B1 (en) * 2000-04-25 2003-12-30 Sp Systems Pte Ltd Dynamic series voltage compensator and method thereof
US20060142964A1 (en) * 2001-11-23 2006-06-29 Abb Ab Fault location using measurements from two ends of a line
US20100001587A1 (en) * 2008-07-01 2010-01-07 Satcon Technology Corporation Photovoltaic dc/dc micro-converter
US20120205981A1 (en) * 2009-09-15 2012-08-16 The University Of Western Ontario Utilization of distributed generator inverters as statcom
US20150318796A1 (en) * 2011-05-08 2015-11-05 Paul Wilkinson Dent Inverter inrush current limiting
CN103326548A (en) * 2013-06-25 2013-09-25 广东电网公司电力科学研究院 Method and system for capacitor voltage control of unified power quality controller
CN103427425A (en) * 2013-08-22 2013-12-04 华北电力大学 Coordinated control device and method for MMC (modular multilevel converter) type unified power quality conditioner
CN103715693A (en) * 2013-11-11 2014-04-09 国家电网公司 Voltage compensation and fault current limiting hybrid system and control method thereof
CN103701145A (en) * 2014-01-02 2014-04-02 浙江大学 Mixed MMC-based mixed direct current power transmission system
CN203942283U (en) * 2014-06-13 2014-11-12 华南理工大学 A kind of three-phase steady state voltage quality control apparatus
CN204118714U (en) * 2014-06-21 2015-01-21 中国能源建设集团广东省电力设计研究院 The alternating current-direct current mating protection device of flexible direct current transmission converter station circuit breaker
CN104505841A (en) * 2014-12-03 2015-04-08 许继电气股份有限公司 Static synchronous power generator reactive support control method for power grid asymmetric short circuit fault
CN104753079A (en) * 2015-03-27 2015-07-01 国家电网公司 Mixed direct-current transmission system capable of implementing inverse power output
CN104811067A (en) * 2015-04-30 2015-07-29 山东大学 PR (proportional resonant) controller-based NMC-HVDC (modular multilevel converter-high voltage direct current) circulating current suppression method
CN104953568A (en) * 2015-07-17 2015-09-30 河南行知专利服务有限公司 Fault protection method for flexible DC power transmission system
CN104993713A (en) * 2015-07-22 2015-10-21 太原理工大学 Control method for double PWM solid-state transformer
CN105119509A (en) * 2015-07-23 2015-12-02 上海电力设计院有限公司 MMC direct circular current inhibition method suitable for asymmetric AC power grid
CN105098833A (en) * 2015-08-12 2015-11-25 国网山东省电力公司电力科学研究院 Asynchronous constant speed wind turbine system for micro grid and working method thereof
CN105207203A (en) * 2015-09-15 2015-12-30 国家电网公司 High-voltage shunt reactor compensation method for typical ultrahigh voltage transmission line

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
HILMY AWAD ET AL: "Mitigation of Unbalanced Voltage Dips", 《IEEE TRANSACTIONS ON POWER ELECTRONICS》 *
孔明等: "《子模块混合型MMC-HVDC 直流故障穿越控制策略》", 《中国电机工程学报》 *
张静等: "《包含VDCCOL 的VSC-HVDC改进控制策略》", 《电力系统自动化》 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115825539A (en) * 2022-10-17 2023-03-21 盛东如东海上风力发电有限责任公司 Voltage and current determination method and system for wind power grid-connected two-phase ground fault
CN115825539B (en) * 2022-10-17 2024-09-03 盛东如东海上风力发电有限责任公司 Method and system for determining voltage and current of wind power grid-connected two-phase ground fault

Also Published As

Publication number Publication date
CN106921157B (en) 2020-08-04

Similar Documents

Publication Publication Date Title
EP2443732B1 (en) An arrangement for exchanging power
Loix et al. Protection of microgrids with a high penetration of inverter-coupled energy sources
EP2786479B1 (en) Power converter
EP3544171B1 (en) Power conversion device
EP3641123A1 (en) Power conversion device
EP2771956B1 (en) Interface arrangement between ac and dc systems for reliable opening of the circuit breaker in time
US10530152B2 (en) Power distribution systems
CN106953347B (en) Method and device for recovering direct-current short-circuit fault of hybrid modular multilevel converter
US11239664B2 (en) Power conversion system
CN106921172B (en) Topological structure of flexible ring network controller
EP3145070B1 (en) Control method and device for three-phase uninterruptible power supply, and three-phase uninterruptible power supply
Carminati et al. Ground fault analysis of low voltage DC micro-grids with active front-end converter
Lazzari et al. Selectivity and security of DC microgrid under line-to-ground fault
US11942873B2 (en) Secondary magnetic excitation generator-motor device
CN109119975A (en) A kind of failure protection method of the breaker of direct current system and its start-up course
WO2015172825A1 (en) Ac fault handling arrangement
US11722069B2 (en) Power conversion system
CN106921157B (en) Alternating-current side single-phase earth fault control method of flexible ring network controller
CN105896477A (en) Grounding protection method of modular multilevel converter and modular multilevel converter
CN114337335B (en) Hybrid modular multilevel converter, control method and control device
KR102071209B1 (en) Power converting apparatus for supplying dc power for dc distributing line
CN110445134B (en) Flexible ring closing device
Chiba et al. DC Fault Ride-Through Control of Half-Bridge MMCs for the HVDC Grid with DC Circuit Breakers
US20230098992A1 (en) Power conversion system
CN111404117B (en) DC blocking device and control method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant