CN113659571A - Prediction device and method for predicting short-circuit current of power grid in-operation transformer in real time - Google Patents
Prediction device and method for predicting short-circuit current of power grid in-operation transformer in real time Download PDFInfo
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- CN113659571A CN113659571A CN202110931924.3A CN202110931924A CN113659571A CN 113659571 A CN113659571 A CN 113659571A CN 202110931924 A CN202110931924 A CN 202110931924A CN 113659571 A CN113659571 A CN 113659571A
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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
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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
- H02H3/08—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 excess current
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/04—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for transformers
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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
- H02J3/04—Circuit arrangements for ac mains or ac distribution networks for connecting networks of the same frequency but supplied from different sources
- H02J3/06—Controlling transfer of power between connected networks; Controlling sharing of load between connected networks
Abstract
The application relates to a prediction device for predicting the short-circuit current of an in-operation transformer of a power grid in real time, which comprises a transformer substation load flow monitoring device, a transformer substation incoming line impedance calculation device and a transformer short-circuit prediction device; the transformer substation tidal current monitoring device is connected with the transformer substation real-time power detection system; the signal input end of the transformer substation incoming line impedance calculation device is connected with the transformer substation real-time power detection system; the signal input end of the transformer short-circuit current prediction device is connected to the signal output end of the transformer substation incoming line impedance calculation device; and the signal output end of the transformer short circuit prediction device is connected to a computer. The transformer short-circuit current prediction method and device have the advantages that transformer circuit parameters in the power grid are monitored in real time through the prediction device for predicting the short-circuit current of the power grid in the operation of the transformer in real time, the prediction value of the short-circuit current of the transformer is calculated, the short-circuit current of the transformer is predicted in real time and monitored, problems are found in advance, and safe and stable operation of the transformer is guaranteed.
Description
Technical Field
The application relates to the field of real-time monitoring and early warning of power elements in a power grid, in particular to a prediction device and method for predicting short-circuit current of an in-operation transformer of the power grid in real time.
Background
With the rapid development of industrial economy in China, the demand for electric power increases at a high rate, and the requirement for reliable supply of electric power is increasing day by day. Therefore, real-time monitoring and early warning of elements in the power grid are required.
As one of the important elements constituting the power grid, the power transformer provides an extremely important role in the safe and reliable power supply of the power grid. However, due to the rapid development and coverage of the power grid, in recent years, power transformer short circuit damage occurs many times at home and abroad, which affects the reliability of power supply of the power grid, and causes huge economic loss and adverse social influence.
In the aspect of short-circuit resistance check of power transformers, a large number of studies are conducted by scholars at home and abroad, but research results are mainly concentrated on a design stage, and the study is insufficient in the aspect of short-circuit resistance check of power transformers.
Therefore, in the operation of the power grid, a device capable of predicting the short-circuit current of the power transformer in operation of the power grid in real time is urgently needed to be found, the power transformer is monitored, and the short-circuit check is carried out by combining the design, so that the safe and stable operation of the power transformer is ensured.
Disclosure of Invention
In order to solve the problems, the application provides a prediction device for predicting the short-circuit current of the transformer in operation of a power grid in real time, which comprises a transformer substation load flow monitoring device, a transformer substation incoming line impedance calculation device and a transformer short-circuit prediction device.
And the transformer substation tide monitoring device is connected with the transformer substation real-time power detection system.
And the signal input end of the transformer substation incoming line impedance calculating device is connected with the transformer substation real-time power detection system.
And the signal input end of the transformer short-circuit current prediction device is connected to the signal output end of the transformer substation incoming line impedance calculation device.
And the signal output end of the transformer short circuit prediction device is connected to a computer.
Optionally, the transformer substation tidal current monitoring device is used for acquiring each tidal current measuring condition of the transformer; the transformer substation incoming line impedance calculation device is used for acquiring line impedance and system impedance according to voltage, current and power transmitted by incoming lines; and the transformer short-circuit current prediction device is used for obtaining the short-circuit current according to the system impedance and the transformer impedance.
In order to realize the real-time monitoring of the short-circuit current of the power transformer, the application also provides a prediction method of a prediction device for predicting the short-circuit current of the transformer in operation of a power grid in real time, which comprises the following steps:
calculating short-circuit impedance values of the transformer under different working conditions according to the operation of the transformer and the power point access mode;
the transformer substation load flow monitoring device acquires circuit parameters of each line point, including power, voltage phase angle deviation and voltage, and transmits the circuit parameters to the transformer substation incoming line impedance calculation device;
the transformer substation limit impedance calculation device calculates the impedance of the line according to the obtained circuit parameters, calculates the system impedance of a plurality of parallel lines according to the impedance of each line, and sends the system impedance to the transformer short circuit prediction device;
the transformer short circuit prediction device receives system impedance data, calculates transformer impedance according to the working condition of the transformer, and calculates the predicted short circuit current value of the transformer in real time by combining system operation voltage.
Optionally, the calculation formula of the line impedance is,
wherein, U1、U2The line voltage is measured on both sides, P is the transmission power, x is the line impedance, and δ is the voltage phase angle deviation.
Optionally, the system impedance may be calculated according to the equivalent of a plurality of lines, and if the lines are connected in series, the system impedance is equal to the sum of the impedances of the lines, and if the lines are connected in parallel, the reciprocal of the system impedance is equal to the sum of the reciprocals of the impedances of the lines.
Optionally, the short-circuit current value of the transformer is predicted by the formula,
I＝U/(Xsystem for controlling a power supply+XTransformer device)；
Wherein U is the system operating voltage, XSystem for controlling a power supplyIs the value of the system impedance, XTransformer deviceIs the transformer impedance value.
Optionally, the transformer impedance calculation method is as follows;
and according to the running state of the transformer, constructing an impedance equivalent circuit diagram of the transformer when the low-voltage side is short-circuited, and calculating short-circuit impedance values of the transformer under different working conditions according to the impedance equivalent circuit diagram of the transformer.
In order to accurately calculate the impedance of the power transformer under different operating conditions, the method for calculating the impedance of the transformer in the application is as follows,
and according to the running state of the transformer, constructing an impedance equivalent circuit diagram of the transformer when the low-voltage side is short-circuited, and calculating short-circuit impedance values of the transformer under different working conditions according to the impedance equivalent circuit diagram of the transformer.
In the application, the transformer circuit parameters in the power grid are monitored in real time through the prediction device for predicting the short-circuit current of the power grid in the operation of the transformer in real time, the predicted value of the short-circuit current of the transformer is calculated, the short-circuit current of the transformer is predicted in real time and monitored, problems are found in advance, and the safe and stable operation of the transformer is guaranteed.
Meanwhile, for the transformers under different working conditions, the short-circuit current of the transformers is respectively calculated through equivalent circuit diagrams, the monitoring accuracy is ensured, and the monitoring and early warning accuracy is further improved.
Therefore, the short-circuit current of the transformer is monitored in real time, and the short-circuit check is carried out in real time by combining with the design check, so that the operation stability of the transformer can be further ensured, the probability of transformer damage caused by short circuit is reduced, the power supply reliability of a power grid is improved, and economic loss and adverse social influence are prevented.
Drawings
In order to more clearly explain the technical solution of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious to those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a connection relationship diagram of a device for predicting a short-circuit current of an in-operation transformer of a power grid according to an embodiment of the present application;
FIG. 2 is a circuit diagram of an equivalent impedance circuit of a three-winding transformer in a short circuit at a low voltage and a high voltage;
fig. 3 is an equivalent circuit diagram of impedance when a three-winding transformer is short-circuited in high-voltage and medium-voltage power supply provided by the embodiment of the application.
Detailed Description
The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
Referring to fig. 1, a connection relationship diagram of a device for predicting a short-circuit current of an on-line transformer of a power grid is provided in the embodiment of the present application.
The application provides a prediction device for predicting the short-circuit current of an on-line transformer of a power grid in real time, which mainly comprises a transformer substation load flow monitoring device, a transformer substation incoming line impedance calculation device and a transformer short-circuit prediction device,
the transformer substation power flow monitoring device is connected to a current input end and a current output end of the transformer and used for obtaining each power flow measuring condition of the transformer.
The signal input end of the transformer substation incoming line impedance calculating device is connected with the signal output end of the transformer substation load flow monitoring device, and line impedance and system impedance are calculated according to voltage, current and power transmitted by incoming lines.
And the signal input end of the transformer short-circuit current prediction device is connected to the signal output end of the transformer incoming line impedance calculation device, and the short-circuit current is calculated according to the system impedance and the transformer impedance.
And the signal output end of the transformer short-circuit prediction device is connected to a computer and used for transmitting the calculated transformer short-circuit current to the computer to monitor and early warn the transformer in real time.
In order to realize real-time monitoring of the short-circuit current of the power transformer, the embodiment of the application further provides a prediction method of a prediction device for predicting the short-circuit current of the transformer in operation of the power grid in real time, which comprises the following steps:
the method comprises the following steps: calculating short-circuit impedance values of the transformer under different working conditions according to the running mode and the power point access mode of the transformer;
step two: the transformer substation load flow monitoring device acquires circuit parameters in each line, wherein the circuit parameters comprise data such as power, voltage phase angle deviation, voltage and the like, and transmits the circuit parameters to the transformer substation incoming line impedance calculation device;
step three: the transformer substation limit impedance calculation device calculates the impedance of the line according to the acquired circuit parameters, calculates the system impedance of a plurality of parallel lines according to the impedance of each line, and sends the system impedance to the transformer short circuit prediction device;
step four: the transformer short circuit prediction device receives system impedance data, calculates transformer impedance according to the working condition of the transformer, and calculates the predicted short circuit current value of the transformer in real time by combining system operation voltage.
In the second step, the calculation formula of the line impedance is as follows,
wherein, U1、U2The line voltage is measured on both sides, P is the transmission power, x is the line impedance, and δ is the voltage phase angle deviation.
In the third step, if the lines are connected in series, the system impedance is equal to the sum of the impedances of the lines, and if the lines are connected in parallel, the reciprocal of the system impedance is equal to the sum of the reciprocals of the impedances of the lines.
In the fourth step, the short-circuit current value of the transformer is predicted by the formula,
I＝U/(Xsystem for controlling a power supply+XTransformer device)；
Wherein U is the system operating voltage, XSystem for controlling a power supplyIs the value of the system impedance, XTransformer deviceIs the transformer impedance value.
In order to accurately calculate the impedance of the power transformer under different operating conditions, the method for calculating the impedance of the transformer in the application is as follows,
and according to the running state of the transformer, constructing an impedance equivalent circuit diagram of the transformer when the low-voltage side is short-circuited, and calculating short-circuit impedance values of the transformer under different working conditions according to the impedance equivalent circuit diagram of the transformer.
In the embodiment of the application, the parameter of the transformer circuit in the power grid is monitored in real time through the prediction device for predicting the short-circuit current of the transformer in the power grid in real time, the predicted value of the short-circuit current of the transformer is calculated, the short-circuit current of the transformer is predicted in real time and monitored, problems are found in advance, and the safe and stable operation of the transformer is guaranteed.
Meanwhile, for the transformers under different working conditions, the short-circuit current of the transformers is respectively calculated through equivalent circuit diagrams, the monitoring accuracy is ensured, and the monitoring and early warning accuracy is further improved.
Therefore, the short-circuit current of the transformer is monitored in real time, and the short-circuit check is carried out in real time by combining with the design check, so that the operation stability of the transformer can be further ensured, the probability of transformer damage caused by short circuit is reduced, the power supply reliability of a power grid is improved, and economic loss and adverse social influence are prevented.
The first embodiment is as follows:
in the actual use process, the transformer substation load flow monitoring device is installed on a power transformer of a transformer substation, wherein the transformer substation load flow monitoring device is connected to a current input end and a current output end of the transformer, a signal input end of a transformer substation incoming line impedance calculation device is connected with a signal output end of the transformer substation load flow monitoring device, a signal input end of a transformer short-circuit current prediction device is connected to a signal output end of the transformer substation incoming line impedance calculation device, and a signal output end of the transformer short-circuit current prediction device is connected to a computer and used for transmitting the calculated transformer short-circuit current to the computer.
After the connection is completed, the transformer substation load flow monitoring device monitors data such as power, voltage phase angle deviation, voltage and the like of the transformer in operation in real time and transmits the data to the transformer substation incoming line impedance calculation device in real time.
After receiving the circuit parameters of the transformer in operation transmitted by the transformer station load flow monitoring device, the transformer station incoming line impedance calculation device substitutes the circuit parameters into a line impedance calculation formula
Respectively calculating the impedance of each line, and calculating the system impedance of the plurality of lines connected in parallel according to the impedance of each line;
meanwhile, according to the working state of each transformer, the short-circuit impedance value of the transformer under different working conditions is calculated. The short-circuit impedance of the transformer is calculated in such a way that,
and constructing an impedance equivalent circuit diagram of the transformer when the low-voltage side is short-circuited, and calculating short-circuit impedance values of the transformer under different working conditions according to the impedance equivalent circuit diagram of the transformer.
When only the high-voltage side of the three-winding transformer is connected with a power supply point and the middle-low sub-side of the transformer is connected with a load, the equivalent circuit diagram of the low-voltage side short-circuit transformer is shown in fig. 2, wherein LV is a low-voltage winding and HV is a high-voltage winding.
When a power supply point is connected to the high-medium voltage side and the low-voltage side of the three-winding transformer in operation, and a load is connected to the low-voltage side, an equivalent circuit diagram of the low-voltage side short-circuit transformer is shown in fig. 3, wherein LV is a low-voltage winding, MV is a medium-voltage winding, and HV is a high-voltage winding.
After the calculation is finished, the system impedance and the short-circuit impedance result of the operating transformer are transmitted to a transformer short-circuit prediction device, the transformer short-circuit prediction device receives system impedance data, calculates the transformer impedance according to the working condition of the transformer, and substitutes the transformer impedance into a formula I of U/(X) in combination with the operating voltage of the systemSystem for controlling a power supply+XTransformer device). And calculating the predicted short-circuit current value of the transformer in real time.
The present application has been described in detail with reference to specific embodiments and illustrative examples, but the description is not intended to limit the application. Those skilled in the art will appreciate that various equivalent substitutions, modifications or improvements may be made to the presently disclosed embodiments and implementations thereof without departing from the spirit and scope of the present disclosure, and these fall within the scope of the present disclosure. The protection scope of this application is subject to the appended claims.
Claims (7)
1. A prediction device for predicting the short-circuit current of an in-operation transformer of a power grid in real time is characterized by comprising a transformer substation load flow monitoring device, a transformer substation incoming line impedance calculation device and a transformer short-circuit prediction device;
the transformer substation tidal current monitoring device is connected with a transformer substation real-time power detection system;
the signal input end of the substation incoming line impedance calculation device is connected with a substation real-time power detection system;
the signal input end of the transformer short-circuit current prediction device is connected to the signal output end of the transformer substation incoming line impedance calculation device;
and the signal output end of the transformer short circuit prediction device is connected to a computer.
2. The device for predicting the short-circuit current of the on-line transformer of the power grid in real time according to claim 1,
the transformer substation tidal current monitoring device is used for acquiring each tidal current measuring condition of the transformer;
the transformer substation incoming line impedance calculation device is used for acquiring line impedance and system impedance according to voltage, current and power transmitted by incoming lines;
and the transformer short-circuit current prediction device is used for obtaining the short-circuit current according to the system impedance and the transformer impedance.
3. The prediction method of the prediction device for predicting the short-circuit current of the on-line transformer of the power grid in real time based on the claim 1 is characterized by comprising the following steps:
calculating short-circuit impedance values of the transformer under different working conditions according to the operation of the transformer and the power point access mode;
the transformer substation load flow monitoring device acquires circuit parameters of each line point, including power, voltage phase angle deviation and voltage, and transmits the circuit parameters to the transformer substation incoming line impedance calculation device;
the transformer substation limit impedance calculation device calculates the impedance of the line according to the obtained circuit parameters, calculates the system impedance of a plurality of parallel lines according to the impedance of each line, and sends the system impedance to the transformer short circuit prediction device;
the transformer short circuit prediction device receives system impedance data, calculates transformer impedance according to the working condition of the transformer, and calculates the predicted short circuit current value of the transformer in real time by combining system operation voltage.
4. The prediction method for predicting the short-circuit current of the on-line transformer of the power grid in real time as claimed in claim 3, wherein the calculation formula of the line impedance is,
wherein, U1、U2The line voltage is measured on both sides, P is the transmission power, x is the line impedance, and δ is the voltage phase angle deviation.
5. The prediction method for predicting the short-circuit current of the in-operation transformer of the power grid in real time according to claim 3, wherein the system impedance can be calculated according to the equivalent value of a plurality of lines, and specifically comprises the following steps:
if the lines are connected in series, the system impedance is equal to the sum of the line impedances, and if the lines are connected in parallel, the reciprocal of the system impedance is equal to the sum of the reciprocal of the line impedances.
6. The prediction method for predicting the short-circuit current of the transformer in real time in the power grid operation process according to claim 3, wherein the short-circuit current value of the transformer is predicted according to the formula,
I＝U/(Xsystem for controlling a power supply+XTransformer device)；
Wherein U is the system operating voltage, XSystem for controlling a power supplyIs the value of the system impedance, XTransformer deviceIs the transformer impedance value.
7. The prediction method for predicting the short-circuit current of the on-line transformer of the power grid in real time according to claim 3, wherein the transformer impedance is calculated by the following method;
and according to the running state of the transformer, constructing an impedance equivalent circuit diagram of the transformer when the low-voltage side is short-circuited, and calculating short-circuit impedance values of the transformer under different working conditions according to the impedance equivalent circuit diagram of the transformer.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006094635A (en) * | 2004-09-24 | 2006-04-06 | Chubu Electric Power Co Inc | Tidal current control method of low-voltage distribution system |
| CN103207344A (en) * | 2013-03-07 | 2013-07-17 | 云南电力试验研究院（集团）有限公司电力研究院 | Method used for checking substation secondary current return circuit and based on main transformer short circuit test |
| CN103560494A (en) * | 2013-11-04 | 2014-02-05 | 国家电网公司 | Method for obtaining setting short-circuit currents protected by power distribution network |
| CN106707028A (en) * | 2016-12-30 | 2017-05-24 | 广东电网有限责任公司惠州供电局 | Transformer short-circuit impedance on-line monitoring method and device |
| WO2018234550A1 (en) * | 2017-06-23 | 2018-12-27 | Ariadna Instruments, S.L. | Method for detecting impedances in an electrical power distribution grid |
| CN109254187A (en) * | 2017-07-14 | 2019-01-22 | 中国电力工程顾问集团华东电力设计院有限公司 | A kind of system and method for determining transformer substation system short circuit current |
| WO2020259415A1 (en) * | 2019-06-26 | 2020-12-30 | 山东电工电气集团智能电气有限公司 | Transformer monitoring method and device and storage medium |
-
2021
- 2021-08-13 CN CN202110931924.3A patent/CN113659571A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006094635A (en) * | 2004-09-24 | 2006-04-06 | Chubu Electric Power Co Inc | Tidal current control method of low-voltage distribution system |
| CN103207344A (en) * | 2013-03-07 | 2013-07-17 | 云南电力试验研究院（集团）有限公司电力研究院 | Method used for checking substation secondary current return circuit and based on main transformer short circuit test |
| CN103560494A (en) * | 2013-11-04 | 2014-02-05 | 国家电网公司 | Method for obtaining setting short-circuit currents protected by power distribution network |
| CN106707028A (en) * | 2016-12-30 | 2017-05-24 | 广东电网有限责任公司惠州供电局 | Transformer short-circuit impedance on-line monitoring method and device |
| WO2018234550A1 (en) * | 2017-06-23 | 2018-12-27 | Ariadna Instruments, S.L. | Method for detecting impedances in an electrical power distribution grid |
| CN109254187A (en) * | 2017-07-14 | 2019-01-22 | 中国电力工程顾问集团华东电力设计院有限公司 | A kind of system and method for determining transformer substation system short circuit current |
| WO2020259415A1 (en) * | 2019-06-26 | 2020-12-30 | 山东电工电气集团智能电气有限公司 | Transformer monitoring method and device and storage medium |
Non-Patent Citations (1)
| Title |
|---|
| 邹德旭等: "变压器运行方式对短路电流的影响", 变压器, vol. 55, no. 8, pages 79 - 82 * |
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