CN105490258B - The DC Line Fault judgment method and control method of Multi-end flexible direct current transmission system - Google Patents
The DC Line Fault judgment method and control method of Multi-end flexible direct current transmission system Download PDFInfo
- Publication number
- CN105490258B CN105490258B CN201510967851.8A CN201510967851A CN105490258B CN 105490258 B CN105490258 B CN 105490258B CN 201510967851 A CN201510967851 A CN 201510967851A CN 105490258 B CN105490258 B CN 105490258B
- Authority
- CN
- China
- Prior art keywords
- line fault
- current
- mmc
- line
- circuit breaker
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- 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
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/22—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for distribution gear, e.g. bus-bar systems; for switching devices
- H02H7/226—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for distribution gear, e.g. bus-bar systems; for switching devices for wires or cables, e.g. heating wires
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/268—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured for dc systems
Abstract
The invention discloses the DC Line Fault control methods of kind of Multi-end flexible direct current transmission system, DC current climbing when it is by increasing direct current inductance value to reduce DC Line Fault, prevent MMC be latched or DC Line Fault during prevent MMC to be latched to reducing bridge arm current the alternating current instruction value zero setting of MMC；Or it is latched MMC in short term during DC Line Fault but does not cut-off the AC circuit breaker of MMC to improve the speed to restore electricity after fault clearance；The invention also discloses a kind of Multi-end flexible direct current transmission system DC Line Fault judgment methods, and by measuring DC inductance line side DC voltage jump rate, when the absolute value of mutation rate is more than certain threshold value, DC Line Fault is had occurred in judgement.The present invention can prevent the AC circuit breaker that MMC is cut-off when DC Line Fault, greatly improve the speed to restore electricity after DC Line Fault removing using the MMC of overhead transmission line, DC Line Fault can be made and fast and accurately be judged simultaneously, convenient for carrying out troubleshooting and control in time, to reduce the risk that MMC bears overcurrent.
Description
Technical field
The invention belongs to electric system transmission & distribution electro-technical fields, more particularly, to a kind of Multi-end flexible direct current transmission system
The DC Line Fault judgment method and control method of system.
Background technique
With the development of modularization multi-level converter (Modular Multilevel Converter, MMC), modularization
Multilevel converter has been increasingly being applied to direct current transportation.Existing MMC mostly uses semi-bridge type submodule, and direct current occurs
Need to be latched the touching of IGBT (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor) when failure
Hair pulse is to prevent submodule capacitor from discharging by IGBT to because overcurrent damages IGBT.After IGBT locking, MMC is worked in
Uncontrollable rectifier state, the AC system that MMC is coupled constantly provide fault current to DC Line Fault point by diode, in order to
The diode for preventing overcurrent damage MMC, needs to cut-off the AC circuit breaker of MMC, and the AC circuit breaker for cut-offfing MMC will significantly
Reduce the power supply reliability of the D.C. high voltage transmission (MMC-HVDC) based on MMC.For this purpose, can in order to improve the power supply of MMC-HVDC
By property, existing MMC-HVDC mostly uses direct current cables as transmission of electricity medium, so that substantially reducing MMC-HVDC occurs direct current
A possibility that failure.
With the development of MMC technology, MMC also will gradually be applied to aerial DC power transmission line, but aerial DC transmission line
The conducting wire on road is exposed in air, and DC Line Fault happens occasionally.It is in the prior art typically all straight to cut-off DC Line Fault
Dc circuit breaker is installed at Flow Line both ends, to cut-off to DC Line Fault.
But since impedance is not present in DC line, when DC Line Fault occurs, direct fault current is by rapid increase, MMC
When using existing control, although even if being mounted with dc circuit breaker on DC line, during DC Line Fault, MMC it is possible to
It is latched after having delayed DC Line Fault to remove, the speed that MMC restores electricity.Moreover, existing MMC control logic, is closed in MMC
The instruction for cut-offfing MMC AC circuit breaker can be issued while lock, so that MMC further be delayed to restore to supply after DC Line Fault removing
The speed of electricity.
In addition, dc circuit breaker is typically mounted at the two sides of DC power transmission line, the failure of multiterminal flexible direct current system is protected
Protecting system is necessary to ensure that the dc circuit breaker that faulty line two sides are only cut-off when DC Line Fault occurs for certain DC line, non-faulting
The dc circuit breaker state of route two sides answer it is unaffected, even if multiterminal flexible direct current system protection have selectivity, be
Reach above-mentioned selectivity to require, it usually needs real-time monitoring and the DC current for comparing DC line two sides work as DC current
When all to flow into line-internal from external system, then judges that DC Line Fault has occurred in this route, need to cut-off route two sides
Dc circuit breaker.Due to needing the physical quantity of alternative route two sides, conventional fault judgment method needs to rely on communication system,
And communication system can bring delay, and in this delay, direct fault current can continue to rise, and cause MMC to be easier to be subjected to overcurrent,
In order to reduce overcurrent, faster DC Line Fault judgment method is needed.
Summary of the invention
Aiming at the above defects or improvement requirements of the prior art, the present invention provides a kind of Multi-end flexible direct current transmission systems
DC Line Fault control method, reduce bridge arm current by the setting of optimization or make bridge arm current without flow through IGBT, thus anti-
The AC circuit breaker that MMC is only cut-off when DC Line Fault is greatly improved and is restored after DC Line Fault removing using the MMC of overhead transmission line
The speed of power supply.
The present invention also provides a kind of judgment methods of the DC Line Fault of Multi-end flexible direct current transmission system, pass through optimization
Design using the mutation rate of DC voltage as judge index, fast and accurately judge so as to be made to DC Line Fault,
Convenient for carrying out troubleshooting and control in time, to reduce the risk that MMC bears overcurrent.
To achieve the above object, according to one aspect of the present invention, a kind of the straight of Multi-end flexible direct current transmission system is provided
Fault control method is flowed, to the DC Line Fault in the DC transmission system based on modularization multi-level converter
Reason, to improve the speed that it restores electricity after fault clearance, which is characterized in that this method includes mould during reducing DC Line Fault
The bridge arm current of block multilevel converter, so that not being latched during modularization multi-level converter failure；Or DC Line Fault
Period lock modules multilevel converter but does not cut-off AC circuit breaker in short-term, and unlocked state is more after DC Line Fault removing
Level converter；Avoid cut-offfing AC circuit breaker by this method and bring time delay, so that realizing can after fault clearance
With fast recovery of power supply.
As present invention further optimization, the bridge arm current for reducing modularization multi-level converter includes reducing bridge
The DC component of arm electric current and/or the AC compounent for reducing bridge arm current.
As present invention further optimization, the DC component for reducing bridge arm current is by increasing dc circuit breaker limit
The inductance value of galvanic electricity sense is realized.
As present invention further optimization, the AC compounent for reducing bridge arm current passes through when DC Line Fault occurs
The alternating current instruction value zero setting of modularization multi-level converter is realized within dc circuit breaker actuation time.
As present invention further optimization, can also additionally connect certain direct current at DC power transmission line both ends
Sense.
Other side according to the invention provides a kind of DC Line Fault controlling party of Multi-end flexible direct current transmission system
Method, for handling the DC Line Fault in the DC transmission system based on modularization multi-level converter, with improve its
The speed to restore electricity after fault clearance, which is characterized in that this method includes increasing the inductance value of dc circuit breaker current-limiting inductance
To reduce the DC component of the bridge arm current of modularization multi-level converter, thus reduce the climbing speed of direct fault current,
And then reduce the increased value of direct fault current during dc circuit breaker cut-offs faulty line, make modularization how electric by this method
Flat inverter is not latched, thus the speed to restore electricity after promoting fault clearance.
As present invention further optimization, can also additionally connect certain direct current at DC power transmission line both ends
Sense.
As present invention further optimization, while can also be during DC Line Fault within dc circuit breaker actuation time
By the alternating current instruction value zero setting of modularization multi-level converter.
Another aspect according to the invention provides a kind of DC Line Fault controlling party of Multi-end flexible direct current transmission system
Method, for handling the DC Line Fault in the DC transmission system based on modularization multi-level converter, with improve its
The speed to restore electricity after fault clearance, which is characterized in that this method includes dynamic in dc circuit breaker during DC Line Fault occurs
Make the alternating current instruction value zero setting in the time by modularization multi-level converter, to reduce modularization multi-level converter
Bridge arm current is latched modularization multi-level converter not by this method, thus the speed to restore electricity after promoting fault clearance
Degree.
As present invention further optimization, after fault clearance, the exchange of recovery module multilevel converter again
Current value is to specified instruction value, to realize normal power supply.
As present invention further optimization, the inductance value of dc circuit breaker current-limiting inductance can also be increased simultaneously to reduce
The DC component of bridge arm current.
As present invention further optimization, can also additionally connect certain direct current at DC power transmission line both ends
Sense.
As present invention further optimization, the DC Line Fault is by monitoring dc circuit breaker close to the direct current in line side
The mutation rate of voltage is quickly judged, i.e., judges that direct current event has occurred inside the DC line when mutation rate is more than threshold value
Barrier, wherein make the difference current DC voltage value and the DC voltage value by the filtering of first-order lag link, and by difference divided by one
The time constant of rank delay component obtains the mutation rate.
Another aspect according to the invention provides a kind of DC Line Fault controlling party of Multi-end flexible direct current transmission system
Method, for handling the DC Line Fault in the DC transmission system based on modularization multi-level converter, with improve its
The speed to restore electricity after fault clearance, which is characterized in that the more level of short time lock modulesization change when DC Line Fault occurs
Device is flowed, but does not issue the instruction for cut-offfing AC circuit breaker, so that electric current is double without flow through the insulated gate of modularization multi-level converter
Gated transistors, thus the speed to restore electricity after promoting fault clearance.
As present invention further optimization, the unlocked state multilevel converter again after fault clearance, with this side
Formula realizes fast recovery of power supply.
As present invention further optimization, the lock modules multilevel converter is to be latched its insulated gate bipolar crystalline substance
Body pipe.
As present invention further optimization, the inductance value of dc circuit breaker current-limiting inductance can also be increased simultaneously to reduce
The DC component of bridge arm current.
As present invention further optimization, can with during DC Line Fault within dc circuit breaker actuation time by module
Change the alternating current instruction value zero setting of multilevel converter.
As present invention further optimization, can also additionally connect certain direct current at DC power transmission line both ends
Sense.
As present invention further optimization, the DC Line Fault is by monitoring dc circuit breaker close to the direct current in line side
The mutation rate of voltage is quickly judged, i.e., judges that direct current event has occurred inside the DC line when mutation rate is more than threshold value
Barrier, wherein make the difference current DC voltage value and the DC voltage value by the filtering of first-order lag link, and by difference divided by one
The time constant of rank delay component obtains the mutation rate.
Another aspect according to the invention provides a kind of quickly sentencing for the DC Line Fault of Multi-end flexible direct current transmission system
Disconnected method, is quickly sentenced for realizing to the DC Line Fault in the DC transmission system based on modularization multi-level converter
It is disconnected, in order to remove failure and fast recovery of power supply in time, which is characterized in that this method includes that monitoring dc circuit breaker leans near line
The mutation rate of the DC voltage of trackside, and when mutation rate is more than threshold value judge that DC Line Fault has occurred inside the DC line,
Wherein, current DC voltage value and the DC voltage value by the filtering of first-order lag link are made the difference, and by difference divided by single order
The time constant of delay component obtains the mutation rate.
As present invention further optimization, the threshold value should meet make it possible to distinguish transmission line of electricity internal direct current failure and
Transmission line of electricity external dc failure.
In general, through the invention it is contemplated above technical scheme is compared with the prior art, can obtain down and show
Beneficial effect:
(1) AC circuit breaker is cut-off to the scheme of isolated DC failure, side provided by the present invention compared to conventional
Case cut-offs AC circuit breaker due to not needing, and reduces so as to restore electricity the required time after MMC failure from tens of seconds
To tens of milliseconds to substantially increase the speed that MMC restores electricity after a failure；
(2) compared to DC Line Fault occurs when, MMC does not do additionally controlled method, the present invention by the control to MMC with
And the coordination of dc circuit breaker parameter, MMC can be prevented to be latched, to avoid cut-offfing for AC circuit breaker, improve MMC in event
The speed to restore electricity after barrier；
(3) compared to the method using conventional design dc circuit breaker current-limiting inductance value, although the present invention is needed certain
Increase dc circuit breaker current-limiting inductance in degree, but since MMC locking can be prevented reliable to substantially increase system power supply
Property；
(4) MMC can be latched during DC Line Fault by taking, but do not issued not open in the solution of the present invention
The instruction of disconnected AC circuit breaker, so that AC circuit breaker is not cut-off, to greatly improve the speed that MMC restores electricity after a failure
Degree；
(5) compared to conventional DC Line Fault judgment method, DC Line Fault judgment method provided by the invention only needs to supervise
The DC voltage for surveying local two sides needs not rely upon communication to greatly improve breakdown judge speed, reduces MMC and bears overcurrent
Risk.
Detailed description of the invention
Equivalent circuit when Fig. 1 is MMC DC Line Fault；
When Fig. 2 is without DC inductance is added, for testing DC Line Fault in the circuit of transmission line of electricity propagation characteristic；
When Fig. 3 is without DC inductance is added, the DC voltage that side point is respectively measured when DC Line Fault occurs；
Fig. 4 is passed for testing DC Line Fault in transmission line of electricity when containing additional DC inductance in one embodiment of the invention
Broadcast the circuit of characteristic；
Fig. 5 is that when containing additional DC inductance in one embodiment of the invention, the direct current that side point is respectively measured when DC Line Fault occurs
Voltage；
Fig. 6 is that DC voltage mutation rate generates logic in one embodiment of the invention；
Fig. 7 be dc circuit breaker in four port multiterminal flexible direct current systems in one embodiment of the invention, DC inductance and
Illustrate the position of DC voltage mutation rate measuring point.
Specific embodiment
In order to make the objectives, technical solutions, and advantages of the present invention clearer, with reference to the accompanying drawings and embodiments, right
The present invention is further elaborated.It should be appreciated that the specific embodiments described herein are merely illustrative of the present invention, and
It is not used in the restriction present invention.As long as in addition, technical characteristic involved in the various embodiments of the present invention described below
Not constituting a conflict with each other can be combined with each other.
The DC Line Fault control method of Multi-end flexible direct current transmission system of the invention, for based on modular multilevel
DC Line Fault in the DC transmission system of inverter is handled, to improve the speed that it restores electricity after fault clearance.
This method by reduce modularization multi-level converter bridge arm current make its be not latched or by make bridge arm current without flow through
It the insulated gate bipolar transistor of modularization multi-level converter and issues it not to cut-off modularization multi-level converter
The instruction of AC circuit breaker cut-offs the AC circuit breaker in DC Line Fault not, so as to after fault clearance
Fast recovery of power supply can be achieved.
Specifically, equivalent circuit when Fig. 1 gives MMC DC Line Fault, wherein Iac, Vac are respectively the exchange of A phase
Electric current and alternating voltage, Ip and In are respectively the electric current of bridge arm and lower bridge arm in A phase, and L0 is bridge arm inductance, and Ldc is direct current interruption
The current-limiting inductance of device, Idc are DC current.Remember the instantaneous value of Iac and Vac are as follows:
Iac=Imcos (ω t+ θ i) (1)
Vac=Vmcos (ω t+ θ v) (2)
Wherein Im and Vm is respectively the maximum value of Iac and Vac, and ω is angular frequency, and θ i and θ v are respectively the phase of Iac and Vac
Angle.Wherein Vm can be addressed further under are as follows:
Vm=MVdcIn/2 (3) formulas (3), M is modulation ratio, representative value 0.9.Side can must be exchanged by formula (1)-(3)
Active power are as follows:
Dc power expression formula are as follows:
Pdc=VdcIdc(5) formula (4) is equal with the value of (5), can obtain
Assuming that the circulation of MMC is adequately suppressed, the expression formula of upper and lower bridge arm current are as follows:
WhereinFor the AC compounent of bridge arm current,For the DC component of bridge arm current.
(1), (6) are substituted into (7) and (8) and can obtained
Representative value M=0.9, θ v=θ v are taken, formula (9)-(10) can be further simplified are as follows:
It can be obtained by formula (11)-(12), in MMC bridge arm current, the peak value of AC compounent is about the 2.22 of DC component peak value
Times.When DC Line Fault occurs, as long as MMC is not at blocking, MMC can control its ac-side current to instruction value, and straight
Galvanic electricity stream will be limited mainly by the current-limiting inductance of dc circuit breaker.The IGBT (insulated gate bipolar transistor) of MMC is no in order to prevent
Because overcurrent is burnt, need to reduce the electric current (i.e. reduction bridge arm current or making bridge arm current without flow through IGBT) for flowing through IGBT.
According to a kind of DC Line Fault controlling party of Multi-end flexible direct current transmission system constructed by one embodiment of the invention
Method reduces bridge arm current, allows to reduce by increasing direct current inductance value to reduce the DC component of bridge arm current
DC current climbing when DC Line Fault, prevents MMC to be latched,
It is specific to determine direct current current-limiting inductance value in the present embodiment, it can be carried out by following process.Remember DC line pole over the ground
The rated value of voltage is Vdcn, DC line rated direct current is Idcn, when the movement of hybrid dc circuit breaker mechanical switch
Between be Tcb, to DC current is limited in K during dc circuit breaker isolated DC failureIIdcnWithin, wherein KIIt is excessively electric
Multiple is flowed, then the acquiring method of dc circuit breaker current-limiting inductance Ldc derives as follows:
It is assumed that the DC voltage of dc circuit breaker maintains V during DC Line Faultdcn, TcbIn time, DC current it is upper
Rising amount are as follows:
I to be madedcLess than KIIdcn, then have
(Idcn+ΔIdc) < KIIdcn (14)
(13) substitution (14) can be obtained
Formula (15) is the Preliminary design formula of direct current current-limiting inductance, in actual use can be on the basis of formula (15), suitably
Designed inductance value is increasedd or decreased, inductance value is finally determined by simulating, verifying.
In another embodiment of the present invention, by the way that the alternating current instruction value zero setting of MMC is subtracted during DC Line Fault
Small AC compounent reduces bridge arm current, and then MMC can be prevented to be latched, and restore MMC AC current values again after fault clearance
To specified instruction value.
In another embodiment, by MMC is latched during DC Line Fault in short term but do not cut-off the AC circuit breaker of MMC from
And improve the speed to restore electricity after fault clearance.It is latched the IGBT of MMC in short-term after detecting DC Line Fault, but does not give MMC
AC circuit breaker hair cut-off instruction so that electric current without flow through IGBT, unlocks the IGBT of MMC again after fault clearance.
Short time can be monitor DC Line Fault to DC Line Fault by dc circuit breaker completely isolated duration,
The time of actual use setting locking can further consider certain nargin on the basis of this time.
Another embodiment according to the invention provides a kind of DC Line Fault judgment method, for realizing to based on modularization
DC Line Fault in the DC transmission system of multilevel converter is quickly judged, simultaneously quickly extensive in order to remove failure in time
Multiple power supply.Such as the present invention it is above-mentioned carry out reduce alternating current and be latched IGBT embodiment in, it is generally preferable to need into
Row quickly judges DC Line Fault.
Fig. 3 is illustrated to 800km DC power transmission line shown in Fig. 2, switch Kflt (simulated failure hair when 0.2s closes a floodgate
It is raw), the DC voltage waveform of each measuring point, it is known that, since failure is propagated in the form of an electromagnetic wave, voltage Vdc4 will be fallen before,
Followed by Vdc3, followed by Vdc2, successively pusher, although each DC voltage has decline, from Fig. 3 can not find out Vdc0~
The significant difference of Vdc4.Fig. 4 is the test circuit after each section of DC line head end has installed DC inductance, and Fig. 5 is switch
Each measuring point voltage waveform that Kflt closes a floodgate in 0.2s, it is known that, in fault propagation to measuring point, Vdc4 and Vdc3 can sharply under
Drop, and Vdc2, Vdc1 and Vdc0 decline are relatively slowly (i.e. descending slope is smaller), it can be seen that DC inductance can be smooth
When DC Line Fault occurs, the fall off rate of DC voltage.As can be seen that being that may determine that DC line is by voltage jump rate
No generation DC Line Fault.
Specifically, i.e., in DC voltage mutation rate more than given threshold, that is, think that DC Line Fault occurs.Wherein voltage is prominent
The principle of variability monitoring link is to make the difference by DC voltage value and by the DC voltage value that first-order lag link filters, by difference
DC voltage mutation rate is obtained divided by the time constant of section filtering link.Fig. 6 is voltage jump rate generation link, wherein
Vdc is DC voltage of the inductance close to line side, and S is DC voltage mutation rate, and Tfil is time constant filter.
Threshold value for carrying out mutation rate comparison should be able to obviously distinguish transmission line of electricity internal direct current failure and transmission line of electricity
External dc failure.In one preferred embodiment, threshold value is determined as follows, i.e., inside transmission line of electricity and transmission line of electricity
Outside applies DC Line Fault respectively, and the minimum for the voltage jump rate that DC Line Fault obtains need to occur lower than transmission line of electricity for threshold value,
And it is higher than the voltage jump rate peak monitored when DC Line Fault occurs outside transmission line of electricity.
In fact, to reach superior technique effect, relevant art means are to can be combined with each other in the various embodiments described above
Or it cooperates, such as while the inductance value by increasing dc circuit breaker current-limiting inductance, direct current event can also be taken simultaneously
By the alternating current instruction value zero setting of modularization multi-level converter within dc circuit breaker actuation time during barrier.It is straight taking
By the side of the alternating current instruction value zero setting of modularization multi-level converter within dc circuit breaker actuation time during stream failure
When formula, while increasing the inductance value of dc circuit breaker current-limiting inductance in route.Can also during taking DC Line Fault the short time
Lock modules multilevel converter but when not issuing the technological means for cut-offfing the instruction of AC circuit breaker, it is dynamic in dc circuit breaker
Make the alternating current instruction value zero setting in the time by modularization multi-level converter, and/or increases dc circuit breaker current-limiting inductance
Inductance value to reduce the DC component of bridge arm current.Correspondingly, preferably right in the various embodiments described above preferably to restore electricity
The DC Line Fault quick discrimination method of the embodiment of the present invention is used in the detection or judgement of DC Line Fault, so that direct current interruption
Device can quickly monitor DC Line Fault and then shorten the total time of isolated DC failure.
Certainly, in the various embodiments described above, route both ends is may also stay at and additionally connected certain DC inductance.Such as Fig. 7,
The embodiment of Fig. 7 gives a kind of had both and improves the multiterminal flexible direct current system that DC Line Fault judges speed and MMC is prevented to be latched
System comprehensive method of protection, principle are when the direct current current-limiting inductance value of dc circuit breaker is inadequate, in route both ends additional strings
Join certain DC inductance, by two sides direct current current-limiting inductance close to the whether exceeded judgement of mutation rate of the DC voltage in line side
Whether DC line occurs DC Line Fault, while limiting event using the inductance of dc circuit breaker and additional increased DC inductance
Fault current when barrier occurs.
As it will be easily appreciated by one skilled in the art that the foregoing is merely illustrative of the preferred embodiments of the present invention, not to
The limitation present invention, any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should all include
Within protection scope of the present invention.
Claims (4)
1. the DC Line Fault control method of a kind of Multi-end flexible direct current transmission system, for based on modularization multi-level converter
DC transmission system in DC Line Fault handled, to improve the speed that it restores electricity after fault clearance, feature
It is, this method includes the bridge arm current of modularization multi-level converter during reducing DC Line Fault, so that modular multilevel
It is not latched during converter fault；Avoid cut-offfing AC circuit breaker by this method and bring time delay, thus realize therefore
Barrier can be with fast recovery of power supply after removing；
The bridge arm current for reducing modularization multi-level converter includes reducing the DC component and reduction bridge arm of bridge arm current
The AC compounent of electric current；
The DC component for reducing bridge arm current is realized by increasing the inductance value of dc circuit breaker current-limiting inductance；
It is described reduce bridge arm current AC compounent by when DC Line Fault occurs within dc circuit breaker actuation time by mould
The alternating current instruction value zero setting of block multilevel converter is realized.
2. a kind of DC Line Fault control method of Multi-end flexible direct current transmission system according to claim 1, wherein also
It can additionally connect DC inductance at DC power transmission line both ends.
3. a kind of DC Line Fault control method of Multi-end flexible direct current transmission system according to claim 1, wherein in event
Hinder after removing, again the AC current values of recovery module multilevel converter to specified instruction value, to realize normal power supply.
4. a kind of DC Line Fault control method of Multi-end flexible direct current transmission system according to claim 1, wherein described
DC Line Fault is quickly judged by monitoring dc circuit breaker close to the mutation rate of the DC voltage in line side, i.e., in mutation rate
Judge that DC Line Fault has occurred inside the DC line when more than threshold value, wherein current DC voltage value and process single order is stagnant
The DC voltage value of metasomite filtering makes the difference, and difference is obtained the mutation divided by the time constant of first-order lag link
Rate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510967851.8A CN105490258B (en) | 2015-12-21 | 2015-12-21 | The DC Line Fault judgment method and control method of Multi-end flexible direct current transmission system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510967851.8A CN105490258B (en) | 2015-12-21 | 2015-12-21 | The DC Line Fault judgment method and control method of Multi-end flexible direct current transmission system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105490258A CN105490258A (en) | 2016-04-13 |
| CN105490258B true CN105490258B (en) | 2018-12-28 |
Family
ID=55677076
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510967851.8A Expired - Fee Related CN105490258B (en) | 2015-12-21 | 2015-12-21 | The DC Line Fault judgment method and control method of Multi-end flexible direct current transmission system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105490258B (en) |
Families Citing this family (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105896488B (en) * | 2016-04-29 | 2018-08-24 | 浙江大学 | A kind of short trouble processing method of the flexible direct current power grid based on combined high-voltage dc circuit breaker |
| CN107346003B (en) * | 2016-05-05 | 2020-09-08 | 南京南瑞继保电气有限公司 | Voltage source converter fault detection and positioning method and system |
| CN105978135B (en) * | 2016-06-22 | 2018-10-19 | 清华大学 | A kind of uninterrupted power exchanger of current source type for alternating-current system |
| CN107666150B (en) * | 2016-07-27 | 2022-04-29 | 全球能源互联网研究院 | Method and device for rapidly protecting direct-current line fault in overhead line flexible direct-current power grid |
| CN106356881B (en) * | 2016-10-21 | 2018-08-17 | 南京南瑞继保电气有限公司 | A kind of flexible direct current power transmission system and its fault recovery method |
| CN106918759B (en) * | 2017-03-16 | 2019-12-10 | 许继集团有限公司 | MMC direct current short-circuit fault detection method and device |
| CN107543998B (en) * | 2017-07-18 | 2020-06-30 | 华北电力大学 | Direct-current side fault positioning system and method for multi-terminal flexible direct-current power transmission system |
| CN107565519B (en) * | 2017-08-18 | 2018-12-28 | 中国南方电网有限责任公司 | A kind of bipolar short-circuit analytic methods of flexible direct current suitable for harmonics |
| CN107966623B (en) * | 2017-10-25 | 2022-05-31 | 全球能源互联网研究院 | Testing method, device and system of modular multilevel converter |
| CN107887906A (en) * | 2017-11-17 | 2018-04-06 | 北京智中电力电子科技有限公司 | A kind of method of operation management method of uninterrupted power exchanger |
| CN108879750A (en) * | 2018-06-29 | 2018-11-23 | 国网浙江省电力有限公司杭州供电公司 | A kind of fault processing system and its control method of Multi-end flexible direct current transmission route |
| CN108879698B (en) * | 2018-07-25 | 2021-01-15 | 国网经济技术研究院有限公司 | Medium voltage distribution network double-ring topological structure comprising four-port flexible switch |
| CN109510179A (en) * | 2018-11-08 | 2019-03-22 | 华北电力大学 | Split-phase damps the direct current cut-off device and method of MMC and AC circuit breaker cooperation |
| WO2020243817A1 (en) * | 2019-06-04 | 2020-12-10 | Transgrid Solutions Inc. | Modified half-bridge submodule for multi-level voltage sourced converter with dc fault suppression capability and related method |
| CN111273192B (en) * | 2020-03-19 | 2022-03-29 | 南京南瑞继保电气有限公司 | Fault backup protection method and device for converter of flexible direct current transmission system |
| CN113451998A (en) * | 2021-06-25 | 2021-09-28 | 许继集团有限公司 | Flexible direct-current voltage abrupt change protection method and device |
| CN115065088A (en) * | 2022-06-30 | 2022-09-16 | 国网江苏省电力有限公司经济技术研究院 | Five-end flexible direct current system additionally provided with superconducting current limiter |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102611096A (en) * | 2012-03-13 | 2012-07-25 | 浙江大学 | Bipolar direct current power transmission system with direct current failure self-elimination capacity |
| CN103066573A (en) * | 2012-12-13 | 2013-04-24 | 国网智能电网研究院 | Modular multi-level multi-terminal flexible direct current system direct current fault handling method |
| CN103066557A (en) * | 2012-12-10 | 2013-04-24 | 国网智能电网研究院 | Modular multi-level flexible direct current system direct current fault overvoltage restraining method |
| CN104617783A (en) * | 2014-12-29 | 2015-05-13 | 天津大学 | Improved structure of MMC (Modular Multilevel Converter) current converter with direct-current fault current-limiting capacity and isolating method |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8830708B2 (en) * | 2009-09-11 | 2014-09-09 | Abb Research Ltd. | Fault current limitation in DC power transmission systems |
| CN102403886B (en) * | 2011-11-03 | 2014-05-07 | 南方电网科学研究院有限责任公司 | Method for protecting direct current line transient short-circuit fault of modular multiple-level converter |
| WO2014121438A1 (en) * | 2013-02-05 | 2014-08-14 | Alstom Technology Ltd. | Method and apparatus for current differential protection for uhvdc transmission line |
-
2015
- 2015-12-21 CN CN201510967851.8A patent/CN105490258B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102611096A (en) * | 2012-03-13 | 2012-07-25 | 浙江大学 | Bipolar direct current power transmission system with direct current failure self-elimination capacity |
| CN103066557A (en) * | 2012-12-10 | 2013-04-24 | 国网智能电网研究院 | Modular multi-level flexible direct current system direct current fault overvoltage restraining method |
| CN103066573A (en) * | 2012-12-13 | 2013-04-24 | 国网智能电网研究院 | Modular multi-level multi-terminal flexible direct current system direct current fault handling method |
| CN104617783A (en) * | 2014-12-29 | 2015-05-13 | 天津大学 | Improved structure of MMC (Modular Multilevel Converter) current converter with direct-current fault current-limiting capacity and isolating method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105490258A (en) | 2016-04-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105490258B (en) | The DC Line Fault judgment method and control method of Multi-end flexible direct current transmission system | |
| Emhemed et al. | Validation of fast and selective protection scheme for an LVDC distribution network | |
| CN106026157B (en) | Flexible direct current transmission converter valve sub-module fault prediction technique and device | |
| CN106093704B (en) | A kind of monitoring of power grid stealing user and localization method and system | |
| CN103715658B (en) | A kind of guard method of Modular multilevel converter bridge arm short circuit fault | |
| KR102542697B1 (en) | Pseudo-bipolar direct current distribution network protection method, device, system, facility and medium | |
| CN106786712B (en) | A kind of commutation failure prediction technique suitable for layer-specific access mode | |
| CN108418196B (en) | Electric current transfevent fault current limiter control method suitable for flexible direct current power grid | |
| CN109256756B (en) | The MMC-HVDC to power to passive network exchanges adaptive reclosing method | |
| CN105449704B (en) | A kind of flexible direct current power transmission system and its DC Line Fault processing method | |
| CN109314393A (en) | Modular multi-level converter unit with integrated current sensors | |
| CN106468752B (en) | The solid circuit breaker RCD buffer circuit and Fault Locating Method of integrated fault location | |
| CN104466945A (en) | Method for analyzing loop closing risks based on interconnection switch in power distribution network | |
| CN105842580A (en) | Voltage sag source accurate location optimization method applicable to intelligent distribution network | |
| CN104597374A (en) | Fault determining method for T type power supply of electric traction network of double tracked railways | |
| CN106451352B (en) | Transformer zero-sequence over-current protection method and protective device with tap switch | |
| CN110021912A (en) | The adaptive reclosing method of multiterminal flexible direct current power grid based on hybrid dc circuit breaker | |
| CN106684841A (en) | Flexible direct-current grid system direct-current short-circuit fault protection method and device | |
| CN113659541A (en) | Multi-terminal direct-current power grid reclosing method and system based on waveform similarity matching | |
| CN109921388A (en) | The direct current cut-off device and method of hybrid MMC and AC circuit breaker cooperation | |
| CN206225994U (en) | The overcurrent protective device and household electrical appliance of power factor corrector | |
| CN206225996U (en) | The overcurrent protective device and household electrical appliance of power factor corrector | |
| CN106329499B (en) | DC earthing guard method for single track reflux power supply system | |
| CN109672153B (en) | AC-DC interconnection system AC differential protection method based on abc-alpha beta change | |
| CN107026466A (en) | Symmetrical bipolar MMC HVDC devices, system and fault traversing control method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB03 | Change of inventor or designer information |
Inventor after: Jiang Lin Inventor after: Hu Jizhou Inventor after: Cheng Jie Inventor after: Tao Fen Inventor after: Wen Jinyu Inventor after: Xie Zhujun Inventor after: Zhang Junjie Inventor before: Jiang Lin Inventor before: Hu Jizhou Inventor before: Cheng Jie Inventor before: Tao Fen Inventor before: Wen Jinyu Inventor before: Xie Zhujun Inventor before: Zhang Junjie |
|
| COR | Change of bibliographic data | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP01 | Change in the name or title of a patent holder | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 430077 197 Xu Dong Street, Hongshan District, Wuhan, Hubei. Patentee after: STATE GRID HUBEI ELECTRIC POWER Co. Patentee after: POWERCHINA HUBEI ELECTRIC ENGINEERING Corp.,Ltd. Patentee after: HUAZHONG University OF SCIENCE AND TECHNOLOGY Address before: 430077 197 Xu Dong Street, Hongshan District, Wuhan, Hubei. Patentee before: STATE GRID HUBEI ELECTRIC POWER Co. Patentee before: HUBEI ELECTRIC POWER SURVEY & DESIGN INSTITUTE Patentee before: HUAZHONG University OF SCIENCE AND TECHNOLOGY |
|
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20181228 Termination date: 20211221 |