CN114050550B - Automatic isolation method for small hydropower nonstandard operation - Google Patents
Automatic isolation method for small hydropower nonstandard operation Download PDFInfo
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- CN114050550B CN114050550B CN202111364123.XA CN202111364123A CN114050550B CN 114050550 B CN114050550 B CN 114050550B CN 202111364123 A CN202111364123 A CN 202111364123A CN 114050550 B CN114050550 B CN 114050550B
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- 238000002955 isolation Methods 0.000 title claims abstract description 18
- 238000000034 method Methods 0.000 claims abstract description 31
- 238000012544 monitoring process Methods 0.000 claims abstract description 5
- 230000002194 synthesizing effect Effects 0.000 claims abstract description 5
- 238000010248 power generation Methods 0.000 abstract description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 11
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 230000003203 everyday effect Effects 0.000 description 1
Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/46—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to frequency deviations
Abstract
The invention provides a small hydropower station nonstandard operation automatic isolation method, which comprises the steps of monitoring and collecting power factors of a small hydropower station on-line, comparing the power factors with standard power factors, synthesizing a first tripping judgment condition, outputting delay out-of-tolerance protection if all inputs are met through AND gate logic judgment, executing a tripping command, and otherwise, operating normally; monitoring and collecting alternating current frequency emitted by small hydropower stations, comparing the alternating current frequency with a set standard frequency interval, synthesizing a second tripping judgment condition, judging through AND gate logic, outputting a delay disconnection function if all inputs are met, executing a tripping command, and otherwise, operating normally; the method solves the problems that the reactive output current of the small hydropower station in the power generation and surfing process of the hydropower station cannot be monitored, the small hydropower generator consumes reactive power in the power generation process, the reactive power in the power system is absorbed, reactive power compensation in the operation process of the generator is performed, the voltage quality of the power system is reduced, and the electric energy quality is lost too much.
Description
Technical Field
The invention relates to the technical field of power grid control, in particular to an automatic isolation method for small hydropower non-standard operation.
Background
At present, small hydropower stations are more in China, the small hydropower stations cannot be required to surf the internet according to a standard power factor in the power generation and surfing process, and only when the electric quantity is manually copied in each month, whether the reactive electric quantity with the work ratio reaches the standard is manually calculated; at present, an automatic isolation protection device is not provided, and power generation in small hydropower peak water seasons is difficult to manage and control because power factors are reduced carelessly or are adjusted manually and intentionally in a surfing process of small hydropower generation; even if power generation is required under the regulation of installing the compensation capacitor, whether the power generation is performed in an under-compensation or full-compensation mode is unknown, and standard power is affected by different layers.
Disclosure of Invention
This section is intended to outline some aspects of embodiments of the invention and to briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section as well as in the description summary and in the title of the application, to avoid obscuring the purpose of this section, the description summary and the title of the invention, which should not be used to limit the scope of the invention.
Therefore, the technical problem to be solved by the invention is to overcome the defect that the non-standard operation of the small hydropower station is difficult to control in the prior art, so as to provide the automatic isolation device for the non-standard operation of the small hydropower station.
In order to solve the technical problems, the invention provides the following technical scheme: the automatic isolating method for small hydropower station nonstandard operation includes monitoring and collecting the power factor of small hydropower station, comparing with standard power factor, synthesizing the first tripping judgment condition, outputting delay out-of-tolerance protection if all inputs are met through AND gate logic judgment, executing tripping command, otherwise, operating normally; the alternating current frequency generated by the small hydropower station is monitored and collected, compared with a set standard frequency interval, and a second tripping judgment condition is synthesized, and the second tripping judgment condition is judged through AND gate logic, so that all inputs meet the output delay disconnection function, a tripping command is executed, and otherwise, the second tripping judgment condition operates normally.
As a preferable scheme of the small water power non-standard operation automatic isolation method, the invention comprises the following steps: the power factor acquisition calculation formula is as follows:
where P is active power, Q is reactive power, S is apparent power.
As a preferable scheme of the small water power non-standard operation automatic isolation method, the invention comprises the following steps: the first tripping judgment conditions comprise automatic pressing plate input, tripping outlet soft pressing plate input and power factor out-of-tolerance protection pressing plate input.
As a preferable scheme of the small water power non-standard operation automatic isolation method, the invention comprises the following steps: the acquisition and calculation formula of the frequency is as follows:
wherein f frequency, n is the motor rotating speed, r/min, p is the pole pair number of the motor rotating magnetic field.
As a preferable scheme of the small water power non-standard operation automatic isolation method, the invention comprises the following steps: the second tripping judgment condition comprises normal operation of a disconnection charging program, voltage of a small hydropower input power grid being smaller than a fixed value of low-frequency disconnection operation, frequency slip locking input and df/dt being larger than or equal to a frequency slip locking fixed value.
As a preferable scheme of the small water power non-standard operation automatic isolation method, the invention comprises the following steps: and in the second tripping judgment condition, the frequency slip locking input and the df/dt are preferably larger than or equal to the frequency slip locking fixed value to carry out AND gate logic judgment, and if the condition is met, the second AND gate logic judgment is carried out with the other second tripping judgment conditions and the frequency meets the standard frequency, and finally, the result of whether to break the gate is obtained.
As a preferable scheme of the small water power non-standard operation automatic isolation method, the invention comprises the following steps: the standard frequency is 50.0Hz, the standard frequency interval is (47.0 Hz,55.0 Hz), the frequency is lower than 47.0Hz to perform low-frequency automatic disconnection tripping, and the frequency is higher than 55.0Hz to perform high-frequency automatic disconnection tripping.
As a preferable scheme of the small water power non-standard operation automatic isolation method, the invention comprises the following steps: the automatic pressing plate is a master switch in management protection logic; and the power factor out-of-tolerance protection pressing plate and the tripping outlet soft pressing plate are the main switches of protection logic.
As a preferable scheme of the small water power non-standard operation automatic isolation method, the invention comprises the following steps: the disconnection charging is an identification program of normal power supply of a small hydropower plant, and the frequency slip is the frequency change rate in unit time.
The invention has the beneficial effects that: by utilizing the power factor out-of-tolerance function, the problems that the reactive output current of the small hydropower station in the process of power generation and surfing can not be monitored, the small hydropower generator consumes reactive power in the process of power generation, the reactive power in the electric power system is absorbed, reactive power compensation is performed in the process of operation of the generator, the voltage quality of the electric power system is reduced, and the electric energy quality is lost too much are solved. The problem that power factor is artificially reduced in the process of surfing the Internet by small hydropower generation, so that small hydropower peak water season power generation, artificial regulation and intentional power factor reduction are caused is solved by using an automatic disconnection tripping function with too low setting frequency.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art. Wherein:
FIG. 1 is a logic circuit for power factor acquisition and discrimination;
FIG. 2 is a logic loop for frequency acquisition and discrimination;
Detailed Description
In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways other than those described herein, and persons skilled in the art will readily appreciate that the present invention is not limited to the specific embodiments disclosed below.
Example 1
At present, small hydropower stations are wide in domestic distribution range and large in quantity, when a power grid is connected to a distributed energy source, the power quality of the power grid is changed due to the change of a grid structure of the system, the power factor is out of tolerance, part of hydropower stations are used for increasing income, active power is increased, reactive power is generated little, the purpose of the small hydropower stations is achieved, the small hydropower stations consume the reactive power, the reactive power in a power system is absorbed, reactive power compensation is carried out on the running process of the power generator, the voltage quality of the power system is reduced, and the power quality is lost too much.
At present, a non-power factor automatic network-releasing device is not researched, so that a great difficulty of whether small hydropower stations generate electricity according to standard power cannot be controlled, and the voltage is lower to operate in a part of time every day, so that the voltage quality of a client is influenced, the service life of key equipment of a power system is also influenced, and therefore, a method for isolating and switching off the small hydropower stations which are not connected on the network according to the standard power factor and frequency in the network-surfing process of the small hydropower stations is needed.
The present embodiment provides a small hydro-electric non-standard operation automatic isolation method, as shown in figures 1 and 2,
the method comprises a nonstandard power factor surfing and nonstandard frequency surfing automatic isolation method, wherein for nonstandard power factor surfing, the power factor of the small hydropower station surfing needs to be monitored and collected, and compared with a standard power factor, a logic judgment standard is determined firstly, namelyThe fixed value is nonstandard power factor for surfing the internet, < >>Representing the real-time power factor of the small hydropower output, namely the ratio of active power to reactive power, +.>The fixed value is a standard power factor, and the power factor input in real time adopts a calculation formula as follows:
wherein P is active power, Q is reactive power, and S is apparent power; the standard power factor is a fixed value considered to be determined, and the measured power factor is compared with the standard power factor.
The power factor discrimination needs to synthesize a first tripping discrimination condition, wherein the first tripping discrimination condition comprises automatic pressing plate input, tripping outlet soft pressing plate input and power factor out-of-tolerance protection pressing plate input, the automatic pressing plate is a main switch in management protection logic, and the power factor out-of-tolerance protection pressing plate and the tripping outlet soft pressing plate are main switches of protection logic.
When all switches are in the input state, the loop is indicated to be in a normal running state, and the logic judgment of an AND gate shows that the small hydropower station does not run according to the standard power factor when all inputs are met, the output delay is out of tolerance protection at the moment, the delay time can be determined by self, then a tripping command is executed, otherwise, the loop indicates that the small hydropower station outputs according to the standard power factor or the system loop of the power grid is out of order, and the small hydropower station is connected into the power grid to run normally.
Further, when the small hydropower station is in non-standard frequency operation and surfing the internet, the frequency of alternating current emitted by the small hydropower station needs to be monitored and collected, and compared with a set standard frequency interval, the collection and calculation formula of the frequency is as follows:
wherein f frequency, n is the motor rotating speed, r/min, p is the pole pair number of the motor rotating magnetic field; the normal standard frequency is 50.0Hz, the standard frequency interval is positioned (47.0 Hz,55.0 Hz), when the frequency is lower than 47.0Hz, the low-frequency automatic disconnection tripping is carried out, and when the frequency is higher than 55.0Hz, the high-frequency automatic disconnection tripping is carried out, whether the tripping isolation condition is met or not also needs to integrate a second tripping judgment condition, the second tripping judgment condition comprises normal running of a disconnection charging program, the voltage of a small hydropower electric power input network is smaller than the fixed value of the low-frequency disconnection running, the frequency slip locking input and df/dt is larger than or equal to the frequency slip locking fixed value, and through AND gate logic judgment, all the inputs meet the requirement, the delay disconnection function is output, and a tripping command is executed, otherwise, the normal running is carried out.
And in the second tripping judgment condition, the frequency slip locking input and the df/dt are preferably greater than or equal to the frequency slip locking fixed value to carry out AND gate logic judgment, if the condition is met, the second AND gate logic judgment is carried out with the rest of the second tripping judgment condition and the frequency meeting the standard frequency, finally, a result of whether to break the gate is obtained, the identification program of normal power supply of the small hydropower plant is obtained through breaking and charging, and the frequency slip is the frequency change rate in unit time.
By utilizing the power factor out-of-tolerance function, the problems that the reactive output current of the small hydropower station in the process of power generation and surfing can not be monitored, the small hydropower generator consumes reactive power in the process of power generation, the reactive power in the electric power system is absorbed, reactive power compensation is performed in the process of operation of the generator, the voltage quality of the electric power system is reduced, and the electric energy quality is lost too much are solved. The problem that power factor is artificially reduced by manually reducing power factor control in the small hydropower generation internet surfing process, so that small hydropower peak water season power generation is caused, and the power factor is intentionally reduced by manually adjusting is solved by utilizing an automatic disconnection tripping function with too low setting frequency.
It should be noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present invention may be modified or substituted without departing from the spirit and scope of the technical solution of the present invention, which is intended to be covered in the scope of the claims of the present invention.
Claims (7)
1. An automatic isolation method for small hydropower nonstandard operation is characterized in that: comprising the steps of (a) a step of,
monitoring and collecting the power factor of the small hydropower station on-line, comparing the power factor with the standard power factor, synthesizing a first tripping judgment condition, judging through AND gate logic, outputting delay out-of-tolerance protection if all inputs are met, executing a tripping command, and otherwise, operating normally;
the first tripping judgment conditions comprise automatic pressing plate input, tripping outlet soft pressing plate input and power factor out-of-tolerance protection pressing plate input;
monitoring and collecting alternating current frequency emitted by small hydropower stations, comparing the alternating current frequency with a set standard frequency interval, synthesizing a second tripping judgment condition, judging through AND gate logic, outputting a delay disconnection function if all inputs are met, executing a tripping command, and otherwise, operating normally;
the second tripping judgment condition comprises normal operation of a disconnection charging program, voltage of the small hydropower input power grid is smaller than a fixed value of low-frequency disconnection operation, frequency slip locking input is carried out, and df/dt is larger than or equal to the fixed value of frequency slip locking.
2. The method for automatically isolating small hydropower non-standard operation according to claim 1, wherein the method comprises the following steps: the power factor acquisition calculation formula is as follows:
where P is active power, Q is reactive power, S is apparent power.
3. The method for automatically isolating small hydropower non-standard operation according to claim 1, wherein the method comprises the following steps: the acquisition and calculation formula of the frequency is as follows:
wherein f frequency, n is the motor rotating speed, r/min, p is the pole pair number of the motor rotating magnetic field.
4. The method for automatically isolating small hydropower non-standard operation according to claim 1, wherein the method comprises the following steps: and in the second tripping judgment condition, the frequency slip locking input and the df/dt are preferably larger than or equal to the frequency slip locking fixed value to carry out AND gate logic judgment, and if the condition is met, the second AND gate logic judgment is carried out with the other second tripping judgment conditions and the frequency meets the standard frequency, and finally, the result of whether to break the gate is obtained.
5. The method for automatically isolating the small hydropower non-standard operation according to claim 4, wherein the method comprises the following steps: the standard frequency is 50.0Hz, the standard frequency interval is (47.0 Hz,55.0 Hz), the frequency is lower than 47.0Hz to perform low-frequency automatic disconnection tripping, and the frequency is higher than 55.0Hz to perform high-frequency automatic disconnection tripping.
6. The method for automatically isolating the small hydropower non-standard operation according to any one of claims 1 or 5, wherein the method comprises the following steps: the automatic pressing plate is a master switch in management protection logic; and the power factor out-of-tolerance protection pressing plate and the tripping outlet soft pressing plate are the main switches of protection logic.
7. The method for automatically isolating the small hydropower non-standard operation according to any one of claims 1 or 5, wherein the method comprises the following steps: the disconnection charging is an identification program of normal power supply of a small hydropower plant, and the frequency slip is the frequency change rate in unit time.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102646992A (en) * | 2012-04-16 | 2012-08-22 | 荣信电力电子股份有限公司 | Power grid fault isolating system for clean energy grid connection |
| CN203149821U (en) * | 2013-04-19 | 2013-08-21 | 国家电网公司 | Small hydropower station operation data and electricity consumption information acquisition and access system |
| CN103956777A (en) * | 2014-04-04 | 2014-07-30 | 国家电网公司 | Method for connecting photovoltaic generated electricity into power grid |
| CN206658099U (en) * | 2016-12-26 | 2017-11-21 | 贵州电网有限责任公司电力调度控制中心 | Small power station's realtime power monitoring and transmitting device |
| CN207053198U (en) * | 2017-08-08 | 2018-02-27 | 神华集团有限责任公司 | Photovoltaic microgrid system |
| CN109286194A (en) * | 2018-10-29 | 2019-01-29 | 贵州电网有限责任公司 | Control system, method and the device of the passive light-operated xegregating unit of high pressure |
| CN109687508A (en) * | 2018-12-06 | 2019-04-26 | 中国电力科学研究院有限公司 | A kind of generation of electricity by new energy unit fast frequency response control mehtod and device |
| CN110609510A (en) * | 2019-10-30 | 2019-12-24 | 广东电网有限责任公司 | Small hydropower intelligent management and control device and system |
-
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- 2021-11-17 CN CN202111364123.XA patent/CN114050550B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102646992A (en) * | 2012-04-16 | 2012-08-22 | 荣信电力电子股份有限公司 | Power grid fault isolating system for clean energy grid connection |
| CN203149821U (en) * | 2013-04-19 | 2013-08-21 | 国家电网公司 | Small hydropower station operation data and electricity consumption information acquisition and access system |
| CN103956777A (en) * | 2014-04-04 | 2014-07-30 | 国家电网公司 | Method for connecting photovoltaic generated electricity into power grid |
| CN206658099U (en) * | 2016-12-26 | 2017-11-21 | 贵州电网有限责任公司电力调度控制中心 | Small power station's realtime power monitoring and transmitting device |
| CN207053198U (en) * | 2017-08-08 | 2018-02-27 | 神华集团有限责任公司 | Photovoltaic microgrid system |
| CN109286194A (en) * | 2018-10-29 | 2019-01-29 | 贵州电网有限责任公司 | Control system, method and the device of the passive light-operated xegregating unit of high pressure |
| CN109687508A (en) * | 2018-12-06 | 2019-04-26 | 中国电力科学研究院有限公司 | A kind of generation of electricity by new energy unit fast frequency response control mehtod and device |
| CN110609510A (en) * | 2019-10-30 | 2019-12-24 | 广东电网有限责任公司 | Small hydropower intelligent management and control device and system |
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