A line protection method and system based on transient power energy and electronic equipment

Abstract

The application discloses a line protection method and system based on transient power energy and electronic equipment, comprising: obtaining measurement current sample values and calculation current sample values on both sides of the line, and obtaining measurement voltage sample values and calculation voltage sample values; calculating differential current and differential voltage based on the measurement current sample values, the calculation current sample values, the measurement voltage sample values and the calculation voltage sample values on both sides of the line; calculating the action amount based on the differential current and the differential voltage; and taking a protection action on both sides of the line when the action amount is greater than a preset braking amount. The application can effectively solve the identification problem caused by the weakening of the fault characteristics by accurately extracting and identifying the fault transient characteristics, can significantly improve the sensitivity and reliability of the protection, and can provide key technical support for guaranteeing the efficient consumption of new energy and the safe and stable operation of the new power system, and can serve the realization of the 'double carbon' strategic goal.

Description

Technical Field

[0001] This invention relates to the field of power system relay protection technology, and more specifically, to a line protection method, system, and electronic equipment based on transient power energy. Background Technology

[0002] With the rapid increase in the penetration rate of new energy sources, the power supply structure and fault characteristics of the power system are undergoing profound changes. New energy units are connected to the grid through power electronic equipment, and their fault response is controlled by the converter control strategy, resulting in complex transient processes and characteristics such as weakened fault features and high harmonic content. This poses a serious challenge to the traditional relay protection principle, which relies on power frequency electrical quantities, as its sensitivity and reliability are significantly reduced. In engineering practice, current differential protection suffers from insufficient sensitivity due to the limited amplitude of fault current, directly threatening the safety of the power grid.

[0003] Therefore, a line protection method based on transient power energy is needed. Summary of the Invention

[0004] This invention proposes a line protection method, system, and electronic equipment based on transient power energy to solve the problem of how to perform line protection efficiently.

[0005] To address the aforementioned problems, according to one aspect of the present invention, a line protection method based on transient power energy is provided, the method comprising:

[0006] Acquire the measured current sampling value, calculated current sampling value, measured voltage sampling value, and calculated voltage sampling value on both sides of the line;

[0007] Based on the measured current sampling value, calculated current sampling value, measured voltage sampling value, and calculated voltage sampling value on both sides of the line, calculate the differential current and differential voltage;

[0008] The action quantity is calculated based on the differential current and differential voltage;

[0009] When the amount of action exceeds the preset braking amount, the protection on both sides of the line will activate.

[0010] Preferably, the differential current and differential voltage are calculated based on the measured current sample values, calculated current sample values, measured voltage sample values, and calculated voltage sample values ​​from both sides of the line, including:

[0011] i diffm =|i M +i Mc |+|i N +i Nc |,

[0012] u diffm =|u M -uMc |+|u N -u Nc |,

[0013] Among them, i diffm For differential current; u diffm For differential voltage; i M For the current sampling value measured on the M side of the line; i N For the current sampling value measured on the N side of the line; i Mc Calculate the sampled current value for the M side of the line; i Nc Calculate the current sampling value for the N side of the line; u M The voltage sample value measured on the M side of the line; u N The voltage sample value measured on the N side of the line; u Mc Calculate the voltage sample value for the M side of the line; u Nc Calculate the voltage sample value for the N side of the line.

[0014] Preferably, the calculation of the action quantity based on the differential current and differential voltage includes:

[0015]

[0016] Among them, S op ΔT is the action quantity; ΔT is the sampling interval; k is the current sampling point number; N is the total number of sampling points within the calculation window; i diffm [n] and u diffm [n] represents the amplitude of the differential current and differential voltage calculated at the nth sampling point, respectively.

[0017] Preferably, the method further includes:

[0018] The braking amount is determined using the following methods:

[0019] S set =K rel ·U N ·I N ,

[0020] Among them, S set K is the preset braking amount. rel U is the reliability coefficient; N The line's rated voltage; I N This is the rated current of the line.

[0021] According to another aspect of the present invention, a line protection system based on transient power energy is provided, the system comprising:

[0022] The sampling value acquisition unit is used to acquire the measured current sampling value, calculated current sampling value, measured voltage sampling value, and calculated voltage sampling value on both sides of the line;

[0023] The differential data calculation unit is used to calculate the differential current and differential voltage based on the measured current sampling value, calculated current sampling value, measured voltage sampling value and calculated voltage sampling value on both sides of the line;

[0024] Action quantity calculation unit, used to calculate action quantity based on the differential current and differential voltage;

[0025] The protection unit is used to activate the protection mechanism on both sides of the line when the action amount exceeds the preset braking amount.

[0026] Preferably, the differential data calculation unit calculates the differential current and differential voltage based on the measured current sample value, calculated current sample value, measured voltage sample value, and calculated voltage sample value on both sides of the line, including:

[0027] i diffm =|i M +i Mc |+|i N +i Nc |,

[0028] u diffm =|u M -u Mc |+|u N -u Nc |,

[0029] Among them, i diffm For differential current; u diffm For differential voltage; i M For the current sampling value measured on the M side of the line; i N For the current sampling value measured on the N side of the line; i Mc Calculate the sampled current value for the M side of the line; i Nc Calculate the current sampling value for the N side of the line; u M The voltage sample value measured on the M side of the line; u N The voltage sample value measured on the N side of the line; u Mc Calculate the voltage sample value for the M side of the line; u Nc Calculate the voltage sample value for the N side of the line.

[0030] Preferably, the action quantity calculation unit calculates the action quantity based on the differential current and differential voltage, including:

[0031]

[0032] Among them, S op ΔT is the action quantity; ΔT is the sampling interval; k is the current sampling point number; N is the total number of sampling points within the calculation window; i diffm [n] and u diffm[n] represents the amplitude of the differential current and differential voltage calculated at the nth sampling point, respectively.

[0033] Preferably, the system further includes:

[0034] The braking amount calculation unit is used to determine the braking amount using the following methods:

[0035] S set =K rel ·U N ·I N ,

[0036] Among them, S set K is the preset braking amount. rel U is the reliability coefficient; N The line's rated voltage; I N This is the rated current of the line.

[0037] According to another aspect of the present invention, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any one of the line protection methods based on transient power energy.

[0038] According to another aspect of the present invention, the present invention provides an electronic device, comprising:

[0039] The aforementioned computer-readable storage medium; and

[0040] One or more processors for executing a program in the computer-readable storage medium.

[0041] This invention provides a line protection method, system, and electronic equipment based on transient power energy, including: acquiring measured current sampling values, calculated current sampling values, measured voltage sampling values, and calculated voltage sampling values ​​from both sides of the line; calculating differential current and differential voltage based on the measured current sampling values, calculated current sampling values, measured voltage sampling values, and calculated voltage sampling values ​​from both sides of the line; calculating the action quantity based on the differential current and differential voltage; and when the action quantity is greater than a preset braking quantity, the protection on both sides of the line operates. This invention effectively addresses the identification difficulties caused by weakened fault characteristics by accurately extracting and identifying transient fault features, significantly improving the sensitivity and reliability of protection, thereby providing key technical support for ensuring the efficient consumption of new energy and the safe and stable operation of new power systems. Attached Figure Description

[0042] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures:

[0043] Figure 1A flowchart of a line protection method 100 based on transient power energy according to an embodiment of the present invention;

[0044] Figure 2 This is a transient power waveform diagram of a line experiencing an external fault according to an embodiment of the present invention;

[0045] Figure 3 This is a transient power waveform diagram of a line fault occurring within the fault zone according to an embodiment of the present invention;

[0046] Figure 4 This is an operation curve diagram of transient power energy protection during line faults according to an embodiment of the present invention;

[0047] Figure 5 This is an operation curve diagram of transient power energy protection when an external fault occurs on a line according to an embodiment of the present invention;

[0048] Figure 6 This is a schematic diagram of the structure of a line protection system 600 based on transient power energy according to an embodiment of the present invention. Detailed Implementation

[0049] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0050] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0051] Figure 1 This is a flowchart of a line protection method 100 based on transient power energy according to an embodiment of the present invention. Figure 1As shown, the line protection method based on transient power energy provided by the embodiments of the present invention effectively addresses the identification difficulties caused by weakened fault characteristics by accurately extracting and identifying transient fault features. This significantly improves the sensitivity and reliability of the protection, thus providing key technical support for ensuring the efficient consumption of new energy and the safe and stable operation of new power systems. The line protection method 100 based on transient power energy provided by the embodiments of the present invention begins at step 101, in which the measured current sampling value, calculated current sampling value, measured voltage sampling value, and calculated voltage sampling value are obtained from both sides of the line.

[0052] Preferably, the differential current and differential voltage are calculated based on the measured current sample values, calculated current sample values, measured voltage sample values, and calculated voltage sample values ​​from both sides of the line, including:

[0053] i diffm =|i M +i Mc |+|i N +i Nc |,

[0054] u diffm =|u M -u Mc |+|u N -u Nc |,

[0055] Among them, i diffm For differential current; u diffm For differential voltage; i M For the current sampling value measured on the M side of the line; i N For the current sampling value measured on the N side of the line; i Mc Calculate the sampled current value for the M side of the line; i Nc Calculate the current sampling value for the N side of the line; u M The voltage sample value measured on the M side of the line; u N The voltage sample value measured on the N side of the line; u Mc Calculate the voltage sample value for the M side of the line; u Nc Calculate the voltage sample value for the N side of the line.

[0056] In step 102, the differential current and differential voltage are calculated based on the measured current sampling value, calculated current sampling value, measured voltage sampling value, and calculated voltage sampling value on both sides of the line.

[0057] In step 103, the action quantity is calculated based on the differential current and differential voltage.

[0058] Preferably, the calculation of the action quantity based on the differential current and differential voltage includes:

[0059]

[0060] Among them, S op ΔT is the action quantity; ΔT is the sampling interval; k is the current sampling point number; N is the total number of sampling points within the calculation window; i diffm [n] and u diffm [n] represents the amplitude of the differential current and differential voltage calculated at the nth sampling point, respectively.

[0061] In step 104, when the action amount is greater than the preset braking amount, the protection on both sides of the line is activated.

[0062] Preferably, the method further includes:

[0063] The braking amount is determined using the following methods:

[0064] S set =K rel ·U N ·I N ,

[0065] Among them, S set K is the preset braking amount. rel U is the reliability coefficient; N The line's rated voltage; I N This is the rated current of the line.

[0066] In this invention, a new protection criterion is constructed to effectively improve the sensitivity and reliability of the protection. Specifically, the transient power energy protection criterion proposed in this invention is based on the characteristic differences in the transient power energy of the line during intra-zone and extra-zone faults. The criterion expression is as follows:

[0067] S op >S set (1)

[0068] In the formula: S op S represents the amount of motion. set The braking amount is the preset power setpoint. When the action amount S... op When the braking amount S is greater than set , ensuring reliable protection.

[0069] Among them, the amount of motion S op The calculation formula is:

[0070]

[0071] In the formula: ΔT is the sampling interval, k is the current sampling point number, N is the total number of sampling points in the calculation window, and i diffm [n]、u diffm [n] represents the amplitude of the differential current and differential voltage calculated at the nth sampling point, respectively.

[0072] Among them, the differential current i diffm With differential voltage u diffm The calculation method is as follows:

[0073] i diffm =|i M +i Mc |+|i N +i Nc | (3)

[0074] u diffm =|u M -u Mc |+|u N -u Nc | (4)

[0075] In the formula: i M The measured current sampling value on the M side of the line is obtained from the real-time sampling of the current transformer used for protection on the M side; i N The measured current sample value on the N side of the line is obtained from real-time sampling of the current transformer used for protection on the N side; i Mc Calculate the sampled current value for the M side of the line; i Nc Calculate the current sampling value for the N side of the line. M The voltage sample value measured on the M side of the line is obtained from the real-time sampling of the voltage transformer used for protection on the M side; u N The voltage sample value measured on the N side of the line is obtained from real-time sampling of the voltage transformer used for protection on the N side; u Mc Calculate the voltage sample value for the M side of the line; u Nc Calculate the voltage sample value for the N side of the line.

[0076] Among them, braking amount S set The calculation formula is:

[0077] S set =K rel ·U N ·I N (5)

[0078] Where: K rel For reliability, a value of 1.2 to 1.5 is recommended; U N The line's rated voltage; I N This is the rated current of the line.

[0079] In this invention, measured current sampling values, calculated current sampling values, measured voltage sampling values, and calculated voltage sampling values ​​are obtained from both sides of the line. Based on these sampling values, the action quantity is calculated, and when the action quantity is greater than the braking quantity, the protection on both sides of the line operates. Through precise electrical quantity calculation and comprehensive criterion construction, this invention can effectively identify subtle fault characteristics in new energy power systems, significantly improve the sensitivity and reliability of line protection, and provide strong support for the safe and stable operation of new power systems.

[0080] Figure 2 The diagram shows the transient power waveform when a fault occurs outside the line's fault zone. It can be seen that the transient power increases to 1154 MVA after the fault. Figure 3 The waveform diagram shows the transient power when a fault occurs within the line's fault zone. It can be seen that the transient power increases to 5,520,000 MVA after the fault. Figure 4 This is the action curve diagram of the transient power energy protection criterion when a fault occurs within the line fault zone. It can be seen that after the fault, the action amount is greater than the braking amount, and the protection operates correctly. Figure 5 The diagram shows the action curve of the transient power energy protection criterion when a fault occurs outside the line protection zone. It can be seen that after the fault, the action amount is less than the braking amount, and the protection reliably does not operate. The power system line protection method based on transient power energy of this invention can accurately identify faults inside and outside the line protection zone.

[0081] Figure 6 This is a schematic diagram of the structure of a line protection system 600 based on transient power energy according to an embodiment of the present invention. Figure 6 As shown, the line protection system 600 based on transient power energy provided by the embodiment of the present invention includes: a sampling value acquisition unit 601, a differential data calculation unit 602, an action quantity calculation unit 603, and a protection unit 604.

[0082] Preferably, the sampling value acquisition unit 601 is used to acquire the measured current sampling value, calculated current sampling value, measured voltage sampling value and calculated voltage sampling value on both sides of the line.

[0083] Preferably, the differential data calculation unit 602 is used to calculate differential current and differential voltage based on the measured current sampling value, calculated current sampling value, measured voltage sampling value and calculated voltage sampling value on both sides of the line.

[0084] Preferably, the differential data calculation unit 602 calculates the differential current and differential voltage based on the measured current sample value, calculated current sample value, measured voltage sample value, and calculated voltage sample value on both sides of the line, including:

[0085] i diffm =|i M +i Mc |+|i N +iNc |,

[0086] u diffm =|u M -u Mc |+|u N -u Nc |,

[0087] Among them, i diffm For differential current; u diffm For differential voltage; i M For the current sampling value measured on the M side of the line; i N For the current sampling value measured on the N side of the line; i Mc Calculate the sampled current value for the M side of the line; i Nc Calculate the current sampling value for the N side of the line; u M The voltage sample value measured on the M side of the line; u N The voltage sample value measured on the N side of the line; u Mc Calculate the voltage sample value for the M side of the line; u Nc Calculate the voltage sample value for the N side of the line.

[0088] Preferably, the action quantity calculation unit 603 is used to calculate the action quantity based on the differential current and differential voltage.

[0089] Preferably, the action quantity calculation unit 603 calculates the action quantity based on the differential current and differential voltage, including:

[0090]

[0091] Among them, S op ΔT is the action quantity; ΔT is the sampling interval; k is the current sampling point number; N is the total number of sampling points within the calculation window; i diffm [n] and u diffm [n] represents the amplitude of the differential current and differential voltage calculated at the nth sampling point, respectively.

[0092] Preferably, the protection unit 604 is used to activate the protection on both sides of the line when the action amount is greater than the preset braking amount.

[0093] Preferably, the system further includes:

[0094] The braking amount calculation unit is used to determine the braking amount using the following methods:

[0095] S set =K rel ·U N ·I N ,

[0096] Among them, S setK is the preset braking amount. rel U is the reliability coefficient; N The line's rated voltage; I N This is the rated current of the line.

[0097] The line protection system 600 based on transient power energy in one embodiment of the present invention corresponds to the line protection method 100 based on transient power energy in another embodiment of the present invention, and will not be described again here.

[0098] According to another aspect of the present invention, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any one of the line protection methods based on transient power energy.

[0099] According to another aspect of the present invention, the present invention provides an electronic device, comprising:

[0100] The aforementioned computer-readable storage medium; and

[0101] One or more processors for executing a program in the computer-readable storage medium.

[0102] The present invention has been described with reference to a few embodiments. However, it will be apparent to those skilled in the art that other embodiments besides those disclosed above fall equivalently within the scope of the present invention.

[0103] Generally, all terms used in this invention are interpreted according to their ordinary meaning in the art, unless otherwise expressly defined herein. All references to “a / the / the [device, component, etc.]” ​​are openly interpreted as at least one instance of said device, component, etc., unless otherwise expressly stated. The steps of any method disclosed herein need not be performed in the exact order disclosed unless explicitly stated otherwise.

[0104] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0105] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0106] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0107] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the present invention.

Claims

1. A line protection method based on transient power energy, characterized in that, The method includes: Acquire the measured current sampling value, calculated current sampling value, measured voltage sampling value, and calculated voltage sampling value on both sides of the line; Based on the measured current sampling value, calculated current sampling value, measured voltage sampling value, and calculated voltage sampling value on both sides of the line, calculate the differential current and differential voltage; The action quantity is calculated based on the differential current and differential voltage; When the amount of action exceeds the preset braking amount, the protection devices on both sides of the line will activate. The differential current and differential voltage are calculated based on the measured current sampling values, calculated current sampling values, measured voltage sampling values, and calculated voltage sampling values ​​from both sides of the line, including: ， ， Among them, i diffm For differential current; u diffm For differential voltage; i M For the current sampling value measured on the M side of the line; i N For the current sampling value measured on the N side of the line; i Mc Calculate the sampled current value for the M side of the line; i Nc Calculate the current sampling value for the N side of the line; u M The voltage sampling value measured on the M side of the line; u N The voltage sample value measured on the N side of the line; u Mc Calculate the voltage sample value for the M side of the line; u Nc Calculate the voltage sample value for the N side of the line; The calculation of the action quantity based on the differential current and differential voltage includes: ， Among them, S op For the amount of motion; The sampling interval is k; the current sampling point number is k; and the total number of sampling points within the calculation window is N. and These are the amplitudes of the differential current and differential voltage calculated at the nth sampling point, respectively.

2. The method according to claim 1, characterized in that, The method further includes: The braking amount is determined using the following methods: ， Among them, S set K is the preset braking amount. rel U is the reliability coefficient; N The line's rated voltage; I N This is the rated current of the line.

3. A line protection system based on transient power energy, characterized in that, The system includes: The sampling value acquisition unit is used to acquire the measured current sampling value, calculated current sampling value, measured voltage sampling value, and calculated voltage sampling value on both sides of the line; The differential data calculation unit is used to calculate the differential current and differential voltage based on the measured current sampling value, calculated current sampling value, measured voltage sampling value and calculated voltage sampling value on both sides of the line; Action quantity calculation unit, used to calculate action quantity based on the differential current and differential voltage; The protection unit is used to activate the protection devices on both sides of the line when the action amount is greater than the preset braking amount. The differential data calculation unit calculates the differential current and differential voltage based on the measured current sample values, calculated current sample values, measured voltage sample values, and calculated voltage sample values ​​from both sides of the line, including: ， ， Among them, i diffm For differential current; u diffm For differential voltage; i M For the current sampling value measured on the M side of the line; i N For the current sampling value measured on the N side of the line; i Mc Calculate the sampled current value for the M side of the line; i Nc Calculate the current sampling value for the N side of the line; u M The voltage sampling value measured on the M side of the line; u N The voltage sample value measured on the N side of the line; u Mc Calculate the voltage sample value for the M side of the line; u Nc Calculate the voltage sample value for the N side of the line; The action quantity calculation unit calculates the action quantity based on the differential current and differential voltage, including: ， Among them, S op For the amount of motion; The sampling interval is k; the current sampling point number is k; and the total number of sampling points within the calculation window is N. and These are the amplitudes of the differential current and differential voltage calculated at the nth sampling point, respectively.

4. The system according to claim 3, characterized in that, The system also includes: The braking amount calculation unit is used to determine the braking amount using the following methods: ， Among them, S set K is the preset braking amount. rel U is the reliability coefficient; N The line's rated voltage; I N This is the rated current of the line.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the steps of the method as described in any one of claims 1-2.

6. An electronic device, characterized in that, include: The computer-readable storage medium as described in claim 5; as well as One or more processors for executing a program in the computer-readable storage medium.

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