CN107528488A - Flexible direct current transmission converter valve submodule switching frequency optimization method and control system - Google Patents
Flexible direct current transmission converter valve submodule switching frequency optimization method and control system Download PDFInfo
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- CN107528488A CN107528488A CN201710720479.XA CN201710720479A CN107528488A CN 107528488 A CN107528488 A CN 107528488A CN 201710720479 A CN201710720479 A CN 201710720479A CN 107528488 A CN107528488 A CN 107528488A
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- Prior art keywords
- submodule
- voltage
- converter valve
- switching frequency
- bridge arm
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
- H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
- H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/21—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/217—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M7/219—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only in a bridge configuration
-
- 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
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/0048—Circuits or arrangements for reducing losses
-
- 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
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
-
- 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]
Abstract
The present invention relates to a kind of flexible direct current transmission converter valve submodule switching frequency optimization method and control system, belong to Power System Flexible technical field of direct current power transmission.The present invention gathers the voltage of all submodules in each bridge arm of converter valve first；Then the voltage of each submodule in this bridge arm is judged whether in setting range, if in setting range, changes the state of the k submodule that switching frequency is minimum in the bridge arm, wherein k is the submodule number that the bridge needs to put into；If uneven in setting range, according to the state of each submodule voltage swing order and sense of current control submodule in this bridge arm, and from keeping the submodule for selecting the minimum equivalent amount of switching frequency in constant submodule to be turned off or open-minded.This invention ensures that on the premise of flexible direct current transmission converter valve submodule voltage unbalance factor, the switching frequency of submodule is significantly reduced, so as to reduce the loss of converter valve, improves the efficiency of flexible DC power transmission.
Description
Technical field
The present invention relates to a kind of flexible direct current transmission converter valve submodule switching frequency optimization method and control system, belong to
Power System Flexible technical field of direct current power transmission.
Background technology
Modular multi-level flexible direct-current transmission (MMC-HVDC) is the HVDC Transmission Technology of a new generation, and flexible direct current
Transmission of electricity is the direct current transportation based on voltage source, and the polarity of voltage of DC line is constant, therefore it is straight to be very easy to composition multiterminal
Stream transmission of electricity, directly it can be powered to the small-sized island load of remote particularly passive system.Flexible direct current transmission converter valve submodule
Block switching frequency is the key factor for influenceing converter valve overall losses.The control for converter valve submodule is using equal at present
Algorithm is pressed, but submodule block instruction caused by algorithm is pressed in simple sequence, causing submodule, frequently switching changes.Cause
This, is required in Practical Project in algorithm performs are pressed, and adds submodule switching frequency optimized algorithm, makes the switching of submodule
Change is lowered, to reduce submodule switching loss.
The submodule larger to being switched on or off voltage in submodule is often taken in traditional submodule switching frequency optimization
Block carries out voltage coefficient correction, that is, is multiplied by a coefficient slightly larger than 1, the submodule is tried one's best in ensuing controlling cycle
Keep original and open off state, so as to reduce submodule switching frequency.Such as the patent that notification number is CN101860203B
File, the patent document disclose a kind of optimization pressure equalizing control method of modular multilevel converter type direct current transmission system,
When bridge arm current makes submodule charge, by excision state and capacitance voltage higher than lower voltage limit submodule electric capacity electricity
Pressure sorts again after being multiplied by the holding factor more than 1, increases in excision state and capacitance voltage is higher than lower voltage limit
Submodule keeps excision shape probability of state when triggering control acts next time；When bridge arm current makes submodule discharge, will be in
The capacitance voltage of the submodule of excision state and capacitance voltage higher than the submodule of upper voltage limit and in input state is multiplied by one
It is individual be more than the 1 holding factor after sort again, increase in the submodule of excision state and capacitance voltage higher than upper voltage limit and
The probability that submodule in input state is put into when triggering control acts next time.Although this method can reduce submodule
The switching frequency of block, but the fluctuation of submodule voltage generation correction factor can be caused, and in submodule voltage difference very little
In the case of also can according to voltage sort result frequently open shut-off.
The content of the invention
It is an object of the invention to provide a kind of flexible direct current transmission converter valve submodule switching frequency optimization method, to ensure
On the premise of flexible direct current transmission converter valve submodule voltage unbalance factor, the switching frequency of submodule is reduced；The present invention also carries
A kind of flexible direct current transmission converter valve control system is supplied.
To there is provided a kind of flexible direct current transmission converter valve submodule switching frequency excellent for solution above-mentioned technical problem by the present invention
Change method, this method comprise the following steps：
1) voltage of all submodules in each bridge arm of converter valve is gathered；
2) judge that the voltage of each submodule in this bridge arm whether in setting range, if in setting range, changes
The state of k minimum submodule of switching frequency in the bridge arm, wherein k are the submodule number that the bridge needs to put into；
If 3) uneven in setting range, son is controlled according to each submodule voltage swing order and the sense of current in this bridge arm
The state of module, and from keep the submodule that the minimum equivalent amount of switching frequency is selected in constant submodule turned off or
Person is open-minded.
Further, described setting range is Vavg- △ V~Vavg+ △ V, wherein VavgPut down for all submodules of this bridge arm
Equal voltage, △ V are permission submodule scope range of the fluctuation of voltage.
Further, it is allowed to which submodule scope range of the fluctuation of voltage △ V can be adjusted according to actual requirement of engineering.
Further, the control process of the step 3) is as follows：
Exceed described setting range when there are x sub- module voltages：
If x>K, then x described submodule is performed into switching all according to control instruction caused by pressure algorithm；
If x<=k, then by described x submodules according to all press algorithms caused by control instruction perform switching, and from
K-x submodule is selected in the relatively low submodule of switching frequency ranking results and performs switching.
Present invention also offers a kind of flexible direct current transmission converter valve control system, the control system include processor and with
Connection voltage collector, described voltage collector is used to gather the voltage of all submodules in each bridge arm of converter valve；Institute
The processor stated is used to judge the voltage of each submodule in this bridge arm whether in setting range, if in setting range,
Change the state of the k submodule that switching frequency is minimum in the bridge arm, wherein k is the submodule number that the bridge needs to put into；If
It is uneven in setting range, then according to the state of each submodule voltage swing order and sense of current control submodule in this bridge arm,
And the submodule that the minimum equivalent amount of switching frequency is selected from the submodule for keeping constant originally is turned off or open-minded.
Further, described setting range is Vavg- △ V~Vavg+ △ V, wherein VavgPut down for all submodules of this bridge arm
Equal voltage, △ V are permission submodule scope range of the fluctuation of voltage.
Further, it is allowed to which submodule scope range of the fluctuation of voltage △ V can be adjusted according to actual requirement of engineering.
Further, when there is x sub- module voltages to exceed described setting range,
If x>X described submodule is performed switching by k, processor all according to control instruction caused by pressure algorithm；
If x<Described x submodules control instruction according to caused by all pressing algorithm is performed switching by=k, processor,
And k-x submodule is selected from the relatively low submodule of switching frequency ranking results and performs switching.
The beneficial effects of the invention are as follows:The present invention gathers the voltage of all submodules in each bridge arm of converter valve first；Then
Judge that the voltage of each submodule in this bridge arm whether in setting range, if in setting range, changes and opened in the bridge arm
The state of k minimum submodule of frequency is closed, wherein k is the submodule number that the bridge needs to put into；If uneven in setting range,
Then according to the state of each submodule voltage swing order and sense of current control submodule in this bridge arm, and from keeping constant son
The submodule that the minimum equivalent amount of switching frequency is selected in module is turned off or open-minded.This invention ensures that flexible direct current
On the premise of current transmission valve submodule voltage unbalance factor, significantly reduce submodule opens shut-off frequency (switch
Frequency), so as to reduce the loss of converter valve, improve the efficiency of flexible DC power transmission.
Brief description of the drawings
Fig. 1 is the flow chart of submodule switching frequency optimization method of the present invention.
Embodiment
The embodiment of the present invention is described further below in conjunction with the accompanying drawings.
In flexible direct current power transmission system, converter valve is to realize the nucleus equipment of AC-DC conversion, and submodule is composition
The elementary cell of converter valve, each bridge arm of converter valve are composed in series by several submodules.All submodules are according to changing
The control instruction of stream valve control system (valve control) turns on and off, and then realizes the AC-DC conversion of whole converter valve.Due to son
Module opens the main contributor that turn-off power loss is own loss, therefore it is to realize submodule loss drop to reduce submodule switching frequency
It is low, while be also the important channel for reducing converter valve loss.
The present invention is directed to the problem of switching frequency is high in converter valve submodule control process, it is proposed that a kind of flexible direct current is defeated
Electric converter valve submodule switching frequency optimization method, this method press algorithm to be combined with submodule, common generation submodule
Shut-off instruction is opened, the flow of this method is as shown in figure 1, this method is realized based on converter valve list bridge arm, and the switch of each bridge arm is frequently
Rate optimization method is identical, is illustrated below by taking any bridge arm as an example, and the number of the bridge arm submodule is n, each submodule voltage
For Vi(i=1...n), each submodule current switch frequency is Fi, each submodule control instruction is Ci, it is allowed to each submodule voltage
Fluctuation range is △ V, and it is k that current control period, which need to put into submodule number,.This method specific implementation step is as follows：
1. gather the voltage V of all submodules in this bridge armi, calculate the average voltage V of each submodule in the bridge armavg。
2. all submodules in the bridge arm are ranked up according to the magnitude of voltage gathered, form the first submodule sequence,
All submodules in the bridge arm are ranked up according to submodule switching frequency, form the second submodule sequence.
3. the magnitude of voltage of all submodules in bridge arm is judged whether in the range of setting, setting range in the present embodiment
Refer to the average voltage V with each submoduleavgCentered on, it is allowed to each submodule scope range of the fluctuation of voltage △ V, can be according to reality
Requirement of engineering, it is appropriate to change △ V, to seek one between submodule voltage unbalance factor and submodule switching frequency optimization knot
Fruit.
If all ViRespectively less than Vavg+ △ V and it is more than Vavg- △ V, then change F in submoduleiK minimum submodule is open-minded
Or off state, the C of other submodulesiRemain unchanged.
If some submodule Vi≥Vavg+ △ V or≤Vavg- △ V, then according to submodule ViRanking results and the sense of current
Opened or turned off, while F is selected from the submodule for keeping constant originallyiThe submodule of minimum equivalent amount is carried out
Shut-off is open-minded.
Such as when there is x sub- module voltages to exceed above-mentioned setting range, if x>K, then this x submodule only press by basis
Control instruction caused by algorithm performs switching and (first carries out voltage sequence, further according to the sense of current and input number k, change x son
The instruction of k submodule in module, other submodules are constant)；If x<=k, then x submodules are all according to caused by pressure algorithm
Control instruction performs switching, and other k-x sub- module instructions select generation from the relatively low submodule of switching frequency ranking results.
Detailed process caused by pressure algorithm is：All submodule voltages of current period are gathered, are arranged from small to large
Sequence, receive current flow direction and input number of modules k that higher level's control unit issues, if the sense of current is just, input
The less k submodule of module voltage, cuts off other submodules；If the sense of current is negative, the larger k of input submodule voltage
Individual submodule, cut off other submodules.
4. the F of each submodule of renewali。
By said process, the optimization to the switching frequency of each bridge arm submodule can be achieved, the present invention is ensureing that flexibility is straight
On the premise of flowing current transmission valve submodule voltage unbalance factor, the switching frequency of submodule is significantly reduced, so as to drop
The loss of low converter valve, improve the efficiency of flexible DC power transmission.
A kind of embodiment of change of current valve control system of the present invention
A kind of flexible direct current transmission converter valve control system in the present embodiment, the control system is including processor and therewith
The voltage collector of connection, voltage collector are used for the voltage for gathering all submodules in each bridge arm of converter valve；Processor is used for
Judge that the voltage of each submodule in this bridge arm whether in setting range, if in setting range, changes and opened in the bridge arm
The state of k minimum submodule of frequency is closed, wherein k is the submodule number that the bridge needs to put into；If uneven in setting range,
Then according to the state of each submodule voltage swing order and sense of current control submodule in this bridge arm, and from keeping constant originally
Submodule in select the submodule of the minimum equivalent amount of switching frequency and turned off or open-minded.Processor specifically controls
Process is described in detail in the embodiment of method, repeats no more here.
The present invention is by being counted and being sorted to the switching frequency of each submodule, its switching state of complex optimum, than
It is simple to be multiplied by coefficient method more precisely and switching frequency is lower (fluctuation range that permission is set to sub- module voltage).
The present invention is not limited to described embodiment, for those of ordinary skill in the art, according to the present invention's
Teaching, the models of the various modifications designed, formula, parameter simultaneously need not spend creative work.Do not departing from the present invention's
The change, modification, replacement and modification carried out in the case of principle and spirit to embodiment still fall within protection scope of the present invention.
Claims (8)
1. a kind of flexible direct current transmission converter valve submodule switching frequency optimization method, it is characterised in that this method includes following
Step：
1) voltage of all submodules in each bridge arm of converter valve is gathered；
2) judge that the voltage of each submodule in this bridge arm whether in setting range, if in setting range, changes the bridge
The state of k minimum submodule of switching frequency in arm, wherein k are the submodule number that the bridge needs to put into；
If 3) uneven in setting range, according to each submodule voltage swing order and sense of current control submodule in this bridge arm
State, and turned off or opened from the submodule for keeping selecting the minimum equivalent amount of switching frequency in constant submodule
It is logical.
2. flexible direct current transmission converter valve submodule switching frequency optimization method according to claim 1, it is characterised in that
Described setting range is Vavg- △ V~Vavg+ △ V, wherein VavgFor all submodule average voltages of this bridge arm, △ V are permission
Submodule scope range of the fluctuation of voltage.
3. flexible direct current transmission converter valve submodule switching frequency optimization method according to claim 2, it is characterised in that
Submodule scope range of the fluctuation of voltage △ V are allowed to be adjusted according to actual requirement of engineering.
4. flexible direct current transmission converter valve submodule switching frequency optimization method according to claim 2, it is characterised in that
The control process of the step 3) is as follows：
Exceed described setting range when there are x sub- module voltages：
If x>K, then x described submodule is performed into switching all according to control instruction caused by pressure algorithm；
If x<=k, then described x submodules control instruction according to caused by all pressing algorithms is performed into switching, and from switch
K-x submodule is selected in the relatively low submodule of frequency ranking results and performs switching.
5. a kind of flexible direct current transmission converter valve control system, it is characterised in that the control system includes processor and connected therewith
The voltage collector connect, described voltage collector are used for the voltage for gathering all submodules in each bridge arm of converter valve；Described
If whether the voltage that processor is used to judge each submodule in this bridge arm, in setting range, changes in setting range
The state of k minimum submodule of switching frequency in the bridge arm, wherein k are the submodule number that the bridge needs to put into；It is if uneven
In setting range, then according to the state of each submodule voltage swing order and sense of current control submodule in this bridge arm, and from
Originally the submodule for selecting the minimum equivalent amount of switching frequency in constant submodule was kept to be turned off or open-minded.
6. flexible direct current transmission converter valve control system according to claim 5, it is characterised in that described setting range
For Vavg- △ V~Vavg+ △ V, wherein VavgFor all submodule average voltages of this bridge arm, △ V are permission submodule voltage pulsation
Scope.
7. flexible direct current transmission converter valve control system according to claim 6, it is characterised in that allow submodule voltage
Fluctuation range △ V can be adjusted according to actual requirement of engineering.
8. flexible direct current transmission converter valve control system according to claim 6, it is characterised in that when there is x submodule
When voltage exceedes described setting range,
If x>X described submodule is performed switching by k, processor all according to control instruction caused by pressure algorithm；
If x<=k, processor control instruction execution switching according to caused by all pressing algorithm by described x submodules, and from
K-x submodule is selected in the relatively low submodule of switching frequency ranking results and performs switching.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710720479.XA CN107528488B (en) | 2017-08-21 | 2017-08-21 | Flexible direct current transmission converter valve submodule switching frequency optimization method and control system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710720479.XA CN107528488B (en) | 2017-08-21 | 2017-08-21 | Flexible direct current transmission converter valve submodule switching frequency optimization method and control system |
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| Publication Number | Publication Date |
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| CN107528488A true CN107528488A (en) | 2017-12-29 |
| CN107528488B CN107528488B (en) | 2019-08-06 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109597298A (en) * | 2018-11-15 | 2019-04-09 | 许继集团有限公司 | The current control method and system of flexible direct current converter valve transient current pilot system |
| CN113364022A (en) * | 2021-05-18 | 2021-09-07 | 中国南方电网有限责任公司超高压输电公司 | Method and system for optimizing switching loss of power sub-module of flexible direct current transmission system |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102130619A (en) * | 2011-03-21 | 2011-07-20 | 中国电力科学研究院 | Voltage balancing control method for multi-level modular converter |
-
2017
- 2017-08-21 CN CN201710720479.XA patent/CN107528488B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102130619A (en) * | 2011-03-21 | 2011-07-20 | 中国电力科学研究院 | Voltage balancing control method for multi-level modular converter |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109597298A (en) * | 2018-11-15 | 2019-04-09 | 许继集团有限公司 | The current control method and system of flexible direct current converter valve transient current pilot system |
| CN109597298B (en) * | 2018-11-15 | 2021-07-09 | 许继集团有限公司 | Current control method and system of flexible direct current converter valve transient current test system |
| CN113364022A (en) * | 2021-05-18 | 2021-09-07 | 中国南方电网有限责任公司超高压输电公司 | Method and system for optimizing switching loss of power sub-module of flexible direct current transmission system |
| CN113364022B (en) * | 2021-05-18 | 2022-05-17 | 中国南方电网有限责任公司超高压输电公司 | Method and system for optimizing switching loss of power sub-module of flexible direct current transmission system |
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