CN109672183A - A kind of flexible direct current loop network system connection transformer tap head adjusting method - Google Patents
A kind of flexible direct current loop network system connection transformer tap head adjusting method Download PDFInfo
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- CN109672183A CN109672183A CN201710950142.8A CN201710950142A CN109672183A CN 109672183 A CN109672183 A CN 109672183A CN 201710950142 A CN201710950142 A CN 201710950142A CN 109672183 A CN109672183 A CN 109672183A
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- tap
- modulation degree
- inverter
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- 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
- H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
-
- 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
- H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
- H02J3/16—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load by adjustment of reactive power
-
- 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
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/30—Reactive power compensation
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Inverter Devices (AREA)
Abstract
The present invention discloses a kind of flexible direct current loop network system connection transformer tap head adjusting method, first determine whether the modulation degree of inverter is limiting in range, when inverter modulation degree exceeds the upper limit, become voltage on valve side direction adjusting tap towards reducing to be coupled, such as adjusts the unsuccessful capacitive reactive power instruction for actively reducing inverter；When inverter modulation degree is lower than the upper limit, becomes voltage on valve side direction adjusting tap towards increasing to be coupled, such as adjust the unsuccessful capacitive reactive power instruction for actively increasing inverter.Such method even if tap failure or gear more in limited time can also the modulation degree to inverter effectively adjusted, guarantee that modulation degree is in restriction range when inverter stable operation.
Description
Technical field
The invention belongs to field of power electronics, in particular to a kind of flexible direct current loop network system is coupled load tap changer tune
Section method.
Background technique
Flexible DC transmission use voltage source converter, can independently, rapidly control active power and reactive power,
To improve the stability of system, inhibits the fluctuation of system frequency and voltage, improve the steady-state performance of grid-connected AC system.It is flexible
Direct current transportation has biggish excellent in fields such as new-energy grid-connected, distributed generation grid-connected, island power supply, urban distribution grid power supplies
Gesture, therefore the research of flexible HVDC transmission related technologie has great importance.
The connection transformer of DC transmission system generally uses on-load voltage regulating switch pressure regulation, makes to be coupled transformer voltage on valve side
Guarantee the safety and economy of inverter operation in appropriate range.Chen Wenyi and Yang Dongdong " change of current change have load adjust
Compress switch control " (Guangdong water conservancy and hydropower, the 6th phase in 2007,92~94) refer to the change of current become on-load voltage regulating switch Principles of Regulation
With the tap-c hange control method of customary DC transmission system, but due to customary DC system and flexible direct current system inverter difference
Larger, this method is not particularly suited for flexible direct current system.
It must assure that its modulation degree (valve side phase voltage fundametal compoment when the inverter stable operation of flexible direct current loop network system
The ratio of amplitude and DC bus-bar voltage half, also known as modulation ratio) in the range of restriction, otherwise inverter will be born excessive
Stress and excessive harmonic wave is brought to influence to system.The tap-c hange control method of flexible direct current loop network system is there is not yet correlation at present
Report.
Summary of the invention
The purpose of the present invention is to provide a kind of flexible direct current loop network system and is coupled transformer tap head adjusting method,
Modulation degree is limiting in range when can guarantee inverter stable operation.
In order to achieve the above objectives, solution of the invention is:
A kind of flexible direct current loop network system connection transformer tap head adjusting method, includes the following steps:
Step 1, judge whether the modulation degree of inverter is limiting in range, such as enter step 2, under being such as lower than beyond the upper limit
Limit enters step 5, otherwise repeatedly step 1；
Step 2, toward connection change voltage on valve side direction adjusting tap is reduced, 3 are entered step；
Step 3, judge whether tap adjusts success, enter step 1 in this way, otherwise enter step 4；
Step 4, the capacitive reactive power instruction for actively reducing inverter, enters step 1；
Step 5, toward connection change voltage on valve side direction adjusting tap is increased, 6 are entered step；
Step 6, judge whether tap adjusts success, enter step 1 in this way, otherwise enter step 7；
Step 7, the capacitive reactive power instruction for actively increasing inverter, enters step 1.
In above-mentioned steps 1, when judging whether the modulation degree of inverter exceeds the upper limit, using stagnant ring manner of comparison, work as modulation
Degree judges that modulation degree beyond the upper limit, subtracts ring width definite value when modulation degree is less than upper limit value Mmax when being greater than upper limit value Mmax
Judge that modulation degree without departing from the upper limit, otherwise keeps whether degree of being originally modulated exceeds the judgement of the upper limit when Hsyt1；Judge inverter
When whether modulation degree is lower than lower limit, using stagnant ring manner of comparison, judge that modulation degree is low when modulation degree is less than lower limit value Mmin
In lower limit, judge that modulation degree not less than lower limit, is otherwise protected when modulation degree is greater than when upper limit value Mmin adds ring width definite value Hsyt2
Hold the judgement whether degree of being originally modulated is lower than lower limit.
The value range of limit value Mmax is 0.01 to 1.5 in above-mentioned modulation degree, and the value range of ring width definite value Hsyt1 is
The value range of 0.001 to 0.5, lower limit value Mmin are 0.01 to 1, the value range of ring width definite value Hsyt2 be 0.001 to
0.5, and Mmax-Hsyt1 is greater than Mmin+Hsyt2.
In above-mentioned steps 3, the successful criterion of tap-c hange control is judged are as follows: the tap-c hange control time is fixed more than tap time-out
Value Ttcc1 or toward reduce be coupled become voltage on valve side direction on tap gear to threshold limit value, the tap time-out definite value
Ttcc1 value is 1s to 1min.
In above-mentioned steps 6, the successful criterion of tap-c hange control is judged are as follows: the tap-c hange control time is fixed more than tap time-out
Value Ttcc2 or toward increase be coupled become voltage on valve side direction on tap gear to threshold limit value, the tap time-out definite value
Ttcc2 value is 1s to 1min.
After adopting the above scheme, the present invention judges the modulation degree of inverter, when inverter modulation degree exceeds the upper limit
When, become voltage on valve side direction adjusting tap towards reducing to be coupled, such as adjusts the unsuccessful capacitive reactive power for actively reducing inverter and refer to
It enables, when inverter modulation degree is lower than the upper limit, adjusts tap towards connection change voltage on valve side direction is increased, such as adjust unsuccessful master
The dynamic capacitive reactive power instruction for increasing inverter.Using this method even if more in limited time can also be to the change of current in tap failure or gear
The modulation degree of device is effectively adjusted, and guarantees the steady-state operation performance of inverter.
Detailed description of the invention
Fig. 1 is flexible direct current loop network system list station structure schematic diagram according to the present invention；
Wherein, figure (a) is the case where being coupled the pressure regulation of load tap changer primary side, and figure (b) is to be coupled load tap changer
The case where secondary side pressure regulation；
Fig. 2 is flow chart of the invention.
Specific embodiment
Below with reference to attached drawing, technical solution of the present invention is described in detail.
As shown in Figure 1, being flexible direct current loop network system list station structure schematic diagram applied by the present invention, Fig. 1 (a) includes handing over
Streaming system S, it is coupled transformer T and inverter C, the on-load voltage regulation tap for being coupled transformer T is located at primary side, taps when adjusting
When head increases first side winding, correspondingly the voltage of secondary side will be reduced, otherwise the voltage of secondary side will increase；Fig. 1 (b) packet
It includes AC system S, be coupled transformer T ' and inverter C, the on-load voltage regulation tap for being coupled transformer T ' is located at secondary side, works as tune
When section tap reduces secondary side winding, correspondingly the voltage of secondary side will be reduced, otherwise the voltage of secondary side will increase.
Fig. 2 is adjusting method flow chart of the present invention, is located at below using on-load voltage regulation tap shown in Fig. 1 (a) primary
The flow chart is described in detail in case where side.Limit value Mmax is set in modulation degree as 0.95, is limited under modulation degree
Value Mmin is 0.75, and ring width definite value Hsyt1 and ring width definite value Hsyt2 are 0.01, tap time-out definite value Ttcc1 and tap
Overtime definite value Ttcc2 is 10s.
Assuming that inverter C stable operation and modulation degree are 0.85 when initial, method provided by the invention starts to judge to adjust
System does not execute any operation in restriction range and continues to judge modulation degree, until modulation degree is beyond the upper limit or is lower than
Lower limit.When AC system S voltage increases or modulation degree is caused to increase to beyond the upper limit 0.95 for the variation of inverter C instruction value,
It will enter and exceed upper limit branch, subsequent sending adjusting tap instruction, which increases first side winding, keeps connection transformer T secondary side electric
Pressure drop is low；When tap-c hange control success, the modulation degree of inverter will be reduced, the instruction before modulation degree decreases below 0.94
It continuously sends out, will be rejudged after modulation degree decreases below 0.94 to limit to instruct in range in modulation degree and cancel；When point
When connector can not be adjusted because of failure, reduce modulation degree the capacitive reactive power for actively reducing inverter instruction more than after 10s, or
When judging that gear is out-of-limit, the capacitive reactive power instruction for also actively reducing inverter reduces modulation degree, is reduced in modulation degree
Modulation degree will rejudge to limit in range after less than 0.94.When the reduction of AC system S voltage or inverter C instruction value
It when variation causes modulation degree lower than lower limit 0.75, will enter lower than lower limit branch, and then issue and adjust tap instruction reduction one
Secondary side winding makes to be coupled the raising of transformer T secondary side voltage；When tap-c hange control success, the modulation degree of inverter will be increased,
The order persistence issues before modulation degree raises to above 0.76, will be rejudged after modulation degree raises to above 0.76 as modulation
Degree is limiting instruction cancellation in range；When tap can not be adjusted because of failure, more than the appearance that will actively increase inverter after 10s
Property reactive command increase modulation degree, or when judging that gear is out-of-limit, the capacitive reactive power for also actively increasing inverter is instructed
Modulation degree is increased, will rejudge after modulation degree raises to above 0.76 and limited in range for modulation degree.
It should be pointed out that the above method, which is equally applicable to on-load voltage regulation tap shown in Fig. 1 (b), is located at secondary side
Situation, difference are to make to be coupled transformer T bis- times by adjusting the tap of secondary side when modulation degree is more than upper limit Mmax
Side voltage increases, and makes to be coupled transformer T secondary side electricity by adjusting the tap of secondary side when modulation degree is lower than lower limit Mmin
Pressure drop is low.
The above examples only illustrate the technical idea of the present invention, and this does not limit the scope of protection of the present invention, all
According to the technical idea provided by the invention, any changes made on the basis of the technical scheme each falls within the scope of the present invention
Within.
Claims (7)
1. a kind of flexible direct current loop network system is coupled transformer tap head adjusting method, it is characterised in that include the following steps:
Step 1, judge whether the modulation degree of inverter is limiting in range, such as enter step 2 beyond the upper limit, such as lower than lower limit into
Enter step 5, otherwise repeatedly step 1；
Step 2, toward connection change voltage on valve side direction adjusting tap is reduced, 3 are entered step；
Step 3, judge whether tap adjusts success, enter step 1 in this way, otherwise enter step 4；
Step 4, the capacitive reactive power instruction for actively reducing inverter, enters step 1；
Step 5, toward connection change voltage on valve side direction adjusting tap is increased, 6 are entered step；
Step 6, judge whether tap adjusts success, enter step 1 in this way, otherwise enter step 7；
Step 7, the capacitive reactive power instruction for actively increasing inverter, enters step 1.
2. a kind of flexible direct current loop network system as described in claim 1 is coupled transformer tap head adjusting method, feature exists
In: in the step 1, when judging whether the modulation degree of inverter exceeds the upper limit, using stagnant ring manner of comparison, when modulation degree is greater than
Modulation degree is judged when upper limit value Mmax beyond the upper limit, when modulation degree is less than the difference of upper limit value Mmax and ring width definite value Hsyt1
When judge modulation degree without departing from the upper limit；When judging whether the modulation degree of inverter is lower than lower limit, using stagnant ring manner of comparison, work as tune
System judges modulation degree lower than lower limit, when modulation degree is greater than upper limit value Mmin and ring width definite value when being less than lower limit value Mmin
Hsyt2 and when judge modulation degree be not less than lower limit.
3. a kind of flexible direct current loop network system as claimed in claim 2 is coupled transformer tap head adjusting method, feature exists
In: the value range of limit value Mmax is 0.01 to 1.5 in the modulation degree, and the value range of ring width definite value Hsyt1 is 0.001
To 0.5, the value range of lower limit value Mmin is 0.01 to 1, and the value range of ring width definite value Hsyt2 is 0.001 to 0.5, and
Mmax-Hsyt1 is greater than Mmin+Hsyt2.
4. a kind of flexible direct current loop network system as described in claim 1 is coupled transformer tap head adjusting method, feature exists
In: in the step 3, judge the successful criterion of tap-c hange control are as follows: the tap-c hange control time is more than tap time-out definite value
Ttcc1 or toward reduce be coupled become voltage on valve side direction on tap gear to threshold limit value.
5. a kind of flexible direct current loop network system as claimed in claim 4 is coupled transformer tap head adjusting method, feature exists
In: the tap time-out definite value Ttcc1 value is 1s to 1min.
6. a kind of flexible direct current loop network system as described in claim 1 is coupled transformer tap head adjusting method, feature exists
In: the step: in 6, judge the successful criterion of tap-c hange control are as follows: the tap-c hange control time is more than tap time-out definite value
Ttcc2 or toward increase be coupled become voltage on valve side direction on tap gear to threshold limit value.
7. a kind of flexible direct current loop network system as claimed in claim 6 is coupled transformer tap head adjusting method, feature exists
In: the tap time-out definite value Ttcc2 value is 1s to 1min.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710950142.8A CN109672183A (en) | 2017-10-13 | 2017-10-13 | A kind of flexible direct current loop network system connection transformer tap head adjusting method |
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| CN201710950142.8A CN109672183A (en) | 2017-10-13 | 2017-10-13 | A kind of flexible direct current loop network system connection transformer tap head adjusting method |
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| CN109672183A true CN109672183A (en) | 2019-04-23 |
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Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104201683A (en) * | 2014-09-11 | 2014-12-10 | 南京南瑞继保电气有限公司 | Flexible direct-current transmission system coupled transformer tap adjusting method |
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- 2017-10-13 CN CN201710950142.8A patent/CN109672183A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104201683A (en) * | 2014-09-11 | 2014-12-10 | 南京南瑞继保电气有限公司 | Flexible direct-current transmission system coupled transformer tap adjusting method |
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Application publication date: 20190423 |
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