CN111130143A - Small hydropower station rapid synchronization method for directly comparing voltage sampling values - Google Patents

Small hydropower station rapid synchronization method for directly comparing voltage sampling values Download PDF

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CN111130143A
CN111130143A CN201911285009.0A CN201911285009A CN111130143A CN 111130143 A CN111130143 A CN 111130143A CN 201911285009 A CN201911285009 A CN 201911285009A CN 111130143 A CN111130143 A CN 111130143A
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voltage
small hydropower
distribution network
hydropower station
rapid synchronization
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CN111130143B (en
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王玕
张紫凡
王智东
陈志峰
林涛
莫锐
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Guangzhou College of South China University of Technology
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Guangzhou College of South China University of Technology
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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
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/40—Synchronising a generator for connection to a network or to another generator

Abstract

The invention provides a small hydropower station rapid synchronization method for directly comparing voltage sampling values, wherein the small hydropower station comprises a voltage transformer and a rapid synchronization system, and the voltage transformer acquires a voltage U on the side of the small hydropower stationXAnd distribution network voltage ULIs conveyed to a quick synchronizing system, and the quick synchronizing system enables the voltage U of the small hydropower sideXAnd distribution network voltage ULComparing, and controlling the reclosing of the small hydropower station to be started by the rapid synchronization system according to a comparison result; in the invention, the acquisition points are randomly selected, so that the reliability of the method is improved; by applying a small hydroelectric side voltage UXAnd distribution network voltage ULDirect comparison is carried out, and when the two are close, direct grid connection is carried out, so that the method is simple and convenient, and the power failure time is shortened; by judging whether a/n is more than or equal to 0.8, the influence of the fluctuation of the voltage or the misdetection of the voltage sampling on the authenticity of the data is avoided.

Description

Small hydropower station rapid synchronization method for directly comparing voltage sampling values
Technical Field
The invention relates to the field of small hydropower station grid connection, in particular to a small hydropower station rapid synchronization method for directly comparing voltage sampling values.
Background
The existing closing schemes all need long waiting time, and at the cost of disconnecting all small power supplies in the area, reclosing needs to be carried out on the small hydropower stations again after the small hydropower stations are disconnected, at the moment, for the distributed small hydropower stations, more time is consumed for re-operating grid connection, the operation is also complex, the recovery of a normal power grid operation mode needs a long time, short-time power failure of a line cannot be avoided, and the requirement of a client on power supply reliability cannot be met.
The existing implementation scheme adopts the existing small hydropower grid-connected intelligent electronic equipment and a multi-purpose full-wave Fourier algorithm, at least one cycle data window (20 ms) is needed, the calculation process is complex, firstly, the full-wave Fourier calculation needs to be carried out on the collected voltages of the small hydropower side and the power distribution network side, then, three quantities of voltage amplitude, phase and frequency of the small hydropower side and the power distribution network side need to be calculated and extracted, and finally, the extracted three quantities of voltage amplitude, phase and frequency need to be compared one by one to judge whether the grid-connected requirement is met.
The method has longer fault detection time, leads to longer power restoration time, and thus leads to lower power supply reliability. Meanwhile, when a fault occurs, the power distribution network adjusts the voltage parameters by cutting off the power supply end or the load end, so that the closing time can be greatly prolonged.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a small hydropower station rapid synchronization method for directly comparing voltage sampling values and switching on in a short time.
In order to achieve the purpose, the technical scheme of the invention is as follows: a small hydropower station rapid synchronization method for directly comparing voltage sampling values comprises a voltage transformer and a rapid synchronization system, wherein the voltage transformer collects voltages on the side of the small hydropower station
Figure 826117DEST_PATH_IMAGE001
And distribution network voltage
Figure 25017DEST_PATH_IMAGE002
Is conveyed to a rapid synchronization system, and the rapid synchronization system enables the voltage of the small hydropower side
Figure 959475DEST_PATH_IMAGE001
And distribution network voltage
Figure 93784DEST_PATH_IMAGE002
Comparing, and controlling the reclosing of the small hydropower station to be started by the rapid synchronization system according to a comparison result;
when the small hydropower stations are synchronized rapidly, the method comprises the following steps:
a) whether the small hydropower station detects tripping; if yes, performing step b);
b) starting a rapid synchronous system, and randomly setting acquisition points, the numerical value of the number n of the acquisition points and the numerical value of a; a is small hydropower side voltage
Figure 113693DEST_PATH_IMAGE001
And distribution network voltage
Figure 381863DEST_PATH_IMAGE002
C) setting the number of the similar conforming points, and finishing the step c);
c) the small hydropower station side voltage of the voltage transformer randomly collecting n numerical values
Figure 170828DEST_PATH_IMAGE001
And distribution network voltage
Figure 725306DEST_PATH_IMAGE002
(ii) a Transmitting the collected data to a rapid synchronization system, and then performing step d);
d) voltage on the small hydropower side of the rapid synchronization system
Figure 498090DEST_PATH_IMAGE001
And distribution network voltage
Figure 304372DEST_PATH_IMAGE002
Making a comparison and then performing step e)
e) Judgment of
Figure 823209DEST_PATH_IMAGE003
If yes, performing step f), and if not, performing step h);
f) proceed with
Figure 689534DEST_PATH_IMAGE004
The operation is carried out according to the operation parameters,
g) judgment of
Figure 418455DEST_PATH_IMAGE005
Whether the judgment is true or not, if so, performing step h); if not, performing step i);
h) starting a reclosing switch;
i) the fast synchronization system will correspond to the small hydropower side voltage at another point in time
Figure 418641DEST_PATH_IMAGE001
And distribution network voltage
Figure 651040DEST_PATH_IMAGE002
A comparison is made and then step e) is performed.
In the method, the acquisition points are randomly selected, so that the reliability of the method is improved; by applying voltage to the small hydropower stations
Figure 688266DEST_PATH_IMAGE001
And distribution network voltage
Figure 904483DEST_PATH_IMAGE002
Direct comparison is carried out, and when the two are close, direct grid connection is carried out, so that the method is simple and convenient, and the power failure time is shortened; by making a judgment
Figure 52568DEST_PATH_IMAGE005
And whether the voltage is true or not is avoided, so that the data authenticity is prevented from being influenced by the fluctuation of the voltage or the misdetection of the voltage sampling.
Further, small hydropower side voltage
Figure 545997DEST_PATH_IMAGE001
And distribution network voltage
Figure 754125DEST_PATH_IMAGE002
The acquisition quantity of the voltage transformer is the same, n sampling time points are randomly set, and the voltage transformer carries out voltage measurement on the small hydropower stations at the same time point
Figure 457639DEST_PATH_IMAGE001
And distribution network voltage
Figure 409414DEST_PATH_IMAGE002
And (5) synchronous acquisition.
Thus ensuring the voltage of the small hydropower side
Figure 6617DEST_PATH_IMAGE001
And distribution network voltage
Figure 385646DEST_PATH_IMAGE002
The synchronism of (2).
Further, the rapid synchronization system corresponds the voltage on the small hydropower side at the same time point
Figure 310877DEST_PATH_IMAGE001
And distribution network voltage
Figure 66343DEST_PATH_IMAGE002
A comparison is made.
Thus small hydroelectric side voltage
Figure 393419DEST_PATH_IMAGE001
And distribution network voltage
Figure 553136DEST_PATH_IMAGE002
Has comparability between them.
Further, the initial value of a is 0 when
Figure 231242DEST_PATH_IMAGE003
If true, the values of a are accumulated.
Thus a is accumulated from 0, improving the reliability of the method.
Drawings
FIG. 1 is a flow chart of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
As shown in figure 1, the small hydropower station rapid synchronization method for directly comparing voltage sampling values comprises a voltage transformer and a rapid synchronization system, wherein the voltage transformer collects voltage on the side of the small hydropower station
Figure 524821DEST_PATH_IMAGE001
And distribution network voltage
Figure 971982DEST_PATH_IMAGE002
Is conveyed to a rapid synchronization system, and the rapid synchronization system enables the voltage of the small hydropower side
Figure 83027DEST_PATH_IMAGE001
And distribution network voltage
Figure 717270DEST_PATH_IMAGE002
And comparing, and controlling the reclosing of the small hydropower station to be started by the rapid synchronization system according to a comparison result.
When the small hydropower stations are synchronized rapidly, the method comprises the following steps:
a) whether the small hydropower station detects tripping; if yes, performing step b);
b) starting a rapid synchronous system, and randomly setting acquisition points, the numerical value of the number n of the acquisition points and the numerical value of a; a is small hydropower side voltage
Figure 548960DEST_PATH_IMAGE001
And distribution network voltage
Figure 116208DEST_PATH_IMAGE002
C) setting the number of the similar conforming points, and finishing the step c);
c) the small hydropower side of the voltage transformer for randomly collecting n numerical valuesVoltage of
Figure 883307DEST_PATH_IMAGE001
And distribution network voltage
Figure 270426DEST_PATH_IMAGE002
(ii) a Transmitting the collected data to a rapid synchronization system, and then performing step d);
d) voltage on the small hydropower side of the rapid synchronization system
Figure 905806DEST_PATH_IMAGE001
And distribution network voltage
Figure 327560DEST_PATH_IMAGE002
Making a comparison and then performing step e)
e) Judgment of
Figure 526547DEST_PATH_IMAGE003
If yes, performing step f), and if not, performing step h);
f) proceed with
Figure 400962DEST_PATH_IMAGE004
The operation is carried out according to the operation parameters,
g) judgment of
Figure 574454DEST_PATH_IMAGE005
Whether the judgment is true or not, if so, performing step h); if not, performing step i);
h) starting a reclosing switch;
i) the fast synchronization system will correspond to the small hydropower side voltage at another point in time
Figure 850715DEST_PATH_IMAGE001
And distribution network voltage
Figure 959616DEST_PATH_IMAGE002
A comparison is made and then step e) is performed.
In the invention, the collection point is the voltage on the small hydropower side
Figure 321328DEST_PATH_IMAGE001
And distribution network side voltage
Figure 298511DEST_PATH_IMAGE002
Is randomly selected in a quarter period, and the value of n is set in the period, wherein n is the voltage of the small hydropower side
Figure 429278DEST_PATH_IMAGE001
And distribution network voltage
Figure 568135DEST_PATH_IMAGE002
The number of acquisition points; small hydropower side voltages with same acquisition quantity and same time point of voltage transformers
Figure 541776DEST_PATH_IMAGE001
And distribution network voltage
Figure 322650DEST_PATH_IMAGE002
(ii) a Thus ensuring the voltage of the small hydropower side
Figure 307924DEST_PATH_IMAGE001
And distribution network voltage
Figure 883262DEST_PATH_IMAGE002
The synchronism of (2). The quick synchronous system enables the corresponding small hydropower side voltage on the same time band point
Figure 94931DEST_PATH_IMAGE001
And distribution network voltage
Figure 413917DEST_PATH_IMAGE002
A comparison is made. This is comparable. a is small hydropower side voltage
Figure 519277DEST_PATH_IMAGE001
And distribution network voltage
Figure 265516DEST_PATH_IMAGE002
Number of similar matchesAmount of the compound (A). The initial value of a is 0. This a improves the reliability of the method.
In the embodiment, the value of n is 5, and the voltage of the small hydropower side
Figure 213749DEST_PATH_IMAGE001
And distribution network voltage
Figure 70847DEST_PATH_IMAGE002
Five are provided. Acquisition points include time point T1, time point T2, time point T3, time point T4, and time point T5; small hydropower side voltage
Figure 30712DEST_PATH_IMAGE001
Including a voltage
Figure 213432DEST_PATH_IMAGE001
1. Voltage of
Figure 134115DEST_PATH_IMAGE001
2. Voltage of
Figure 794903DEST_PATH_IMAGE001
3. Voltage of
Figure 874855DEST_PATH_IMAGE001
4 and voltage
Figure 962896DEST_PATH_IMAGE001
5; distribution network voltage
Figure 620143DEST_PATH_IMAGE002
Including a voltage
Figure 84622DEST_PATH_IMAGE002
1. Voltage of
Figure 753501DEST_PATH_IMAGE002
2. Voltage of
Figure 278023DEST_PATH_IMAGE002
3. Voltage of
Figure 32352DEST_PATH_IMAGE002
4 and voltage
Figure 910310DEST_PATH_IMAGE002
5。
Voltage of
Figure 699274DEST_PATH_IMAGE001
1. Voltage of
Figure 394698DEST_PATH_IMAGE001
2. Voltage of
Figure 901902DEST_PATH_IMAGE001
3. Voltage of
Figure 567239DEST_PATH_IMAGE001
4 and voltage
Figure 476289DEST_PATH_IMAGE001
5 are respectively small hydropower side voltage
Figure 77035DEST_PATH_IMAGE001
Real-time voltages at time point T1, time point T2, time point T3, time point T4, and time point T5.
Voltage of
Figure 71535DEST_PATH_IMAGE002
1. Voltage of
Figure 291295DEST_PATH_IMAGE002
2. Voltage of
Figure 54852DEST_PATH_IMAGE002
3. Voltage of
Figure 92078DEST_PATH_IMAGE002
4 and voltage
Figure 308296DEST_PATH_IMAGE002
5 distribution network voltages respectively
Figure 581014DEST_PATH_IMAGE002
Real-time voltages at time point T1, time point T2, time point T3, time point T4, and time point T5.
At time point T1, the voltage transformer couples the voltages
Figure 933498DEST_PATH_IMAGE001
1 and voltage
Figure 141626DEST_PATH_IMAGE002
1, collecting; at time point T2, the voltage transformer couples the voltages
Figure 845139DEST_PATH_IMAGE001
2 and voltage
Figure 531336DEST_PATH_IMAGE002
2, collecting; voltage transformer pair voltage at time point T3
Figure 144851DEST_PATH_IMAGE001
3 and voltage
Figure 523879DEST_PATH_IMAGE002
3, collecting; at time point T4, the voltage transformer couples the voltages
Figure 714689DEST_PATH_IMAGE001
4 and voltage
Figure 204576DEST_PATH_IMAGE002
4, collecting the voltage of the voltage transformer at a time point T5
Figure 656286DEST_PATH_IMAGE001
5 and voltage
Figure 206216DEST_PATH_IMAGE002
And 5, collecting.
Fast synchronization system will voltage
Figure 884322DEST_PATH_IMAGE001
1 and voltage
Figure 177901DEST_PATH_IMAGE002
1, carrying out comparison; when voltage is applied
Figure 500429DEST_PATH_IMAGE001
1 and voltage
Figure 955681DEST_PATH_IMAGE002
1 are similar in value; the time point T1 is a coincidence point; then there is one coincident point in the five acquisition points; and when the proportion of the coincidence point in the acquisition point reaches more than 80%, starting a reclosing switch to close the switch.
In the method, the acquisition points are randomly selected, so that the reliability of the method is improved; by applying voltage to the small hydropower stations
Figure 121083DEST_PATH_IMAGE001
And distribution network voltage
Figure 952773DEST_PATH_IMAGE002
Direct comparison is carried out, and when the two are close, direct grid connection is carried out, so that the method is simple and convenient, and the power failure time is shortened; by making a judgment
Figure 254441DEST_PATH_IMAGE005
And whether the voltage is true or not is avoided, so that the data authenticity is prevented from being influenced by the fluctuation of the voltage or the misdetection of the voltage sampling.

Claims (4)

1. A small hydropower rapid synchronization method for directly comparing voltage sampling values is characterized in that: the small hydropower station comprises a voltage transformer and a rapid synchronization system, wherein the voltage transformer is used for collecting the voltage U of the small hydropower station sideXAnd distribution network voltage ULIs conveyed to a quick synchronizing system, and the quick synchronizing system enables the voltage U of the small hydropower sideXAnd distribution network voltage ULComparing, and controlling the reclosing of the small hydropower station to be started by the rapid synchronization system according to a comparison result;
when the small hydropower stations are synchronized rapidly, the method comprises the following steps:
a) whether the small hydropower station detects tripping; if yes, performing step b);
b) starting a rapid synchronous system, and randomly setting acquisition points, the numerical value of the number n of the acquisition points and the numerical value of a; a is small hydropower side voltage UXAnd distribution network voltage ULC) setting the number of the similar conforming points, and finishing the step c);
c) small hydropower side voltage U with voltage transformer randomly collecting n valuesXAnd distribution network voltage UL(ii) a Transmitting the collected data to a rapid synchronization system, and then performing step d);
d) the fast synchronization system will be small hydropower side voltage UXAnd distribution network voltage ULComparing, and then carrying out step e);
e) judge UX≈|ULIf |, performing step f) if the |, and if not, performing step i);
f) the a = a +1 operation is performed,
g) judging whether a/n is more than or equal to 0.8, if yes, performing step h); if not, performing step i);
h) starting a reclosing switch;
i) the fast synchronization system will correspond to the small hydropower side voltage U at another point in timeXAnd distribution network voltage ULA comparison is made and then step e) is performed.
2. The small hydropower station rapid synchronization method for directly comparing voltage sampling values according to claim 1, wherein the method comprises the following steps: small hydropower side voltage UXAnd distribution network voltage ULThe acquisition quantity of the voltage transformer is the same, n sampling time points are randomly set, and the voltage transformer carries out voltage U on the small hydropower station side at the same time pointXAnd distribution network voltage ULAnd (5) synchronous acquisition.
3. The small hydropower station rapid synchronization method for directly comparing voltage sampling values according to claim 2, wherein the method comprises the following steps: the quick synchronization system enables the corresponding small hydropower side voltage U at the same time pointXAnd distribution network voltage ULA comparison is made.
4. The small hydropower station rapid synchronization method for directly comparing voltage sampling values according to claim 1, wherein the method comprises the following steps: a is initially 0 when UX≈|ULIf |, the values of a are accumulated.
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Citations (8)

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CN101719679A (en) * 2009-12-21 2010-06-02 中国电力科学研究院 Method for synchronizing distributed power supply and power grid
CN101876690A (en) * 2010-05-28 2010-11-03 长沙威克电力技术科技有限公司 Generator contemporary process monitoring and analyzing system
CN102075001A (en) * 2010-06-25 2011-05-25 广东省电力调度中心 Intelligent incoming line backup power automatic switching method and device suitable for areas with abundant small hydroelectric stations
CN103560535A (en) * 2013-11-20 2014-02-05 北京四方继保自动化股份有限公司 Micro-grid operation mode seamless switching method based on energy storage current transformer
CN103795087A (en) * 2014-02-20 2014-05-14 国电南瑞科技股份有限公司 Control method for smooth and synchronous grid connection of mircrogrid
CN106026195A (en) * 2016-07-21 2016-10-12 中国电力科学研究院 Microgrid group synchronous closing grid-connection control method
US10103544B2 (en) * 2016-02-05 2018-10-16 Sungrow Power Supply Co., Ltd. Medium and high voltage grid-connected power generation system, medium and high voltage grid-connected system and control unit thereof
CN110429660A (en) * 2019-07-19 2019-11-08 国家电网有限公司 A kind of generator connecting in parallel with system asynchronous switch-on pulse issues the determination method of time

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101719679A (en) * 2009-12-21 2010-06-02 中国电力科学研究院 Method for synchronizing distributed power supply and power grid
CN101876690A (en) * 2010-05-28 2010-11-03 长沙威克电力技术科技有限公司 Generator contemporary process monitoring and analyzing system
CN102075001A (en) * 2010-06-25 2011-05-25 广东省电力调度中心 Intelligent incoming line backup power automatic switching method and device suitable for areas with abundant small hydroelectric stations
CN103560535A (en) * 2013-11-20 2014-02-05 北京四方继保自动化股份有限公司 Micro-grid operation mode seamless switching method based on energy storage current transformer
CN103795087A (en) * 2014-02-20 2014-05-14 国电南瑞科技股份有限公司 Control method for smooth and synchronous grid connection of mircrogrid
US10103544B2 (en) * 2016-02-05 2018-10-16 Sungrow Power Supply Co., Ltd. Medium and high voltage grid-connected power generation system, medium and high voltage grid-connected system and control unit thereof
CN106026195A (en) * 2016-07-21 2016-10-12 中国电力科学研究院 Microgrid group synchronous closing grid-connection control method
CN110429660A (en) * 2019-07-19 2019-11-08 国家电网有限公司 A kind of generator connecting in parallel with system asynchronous switch-on pulse issues the determination method of time

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