Distance protection method, device, computer equipment and program product for transmission line

Abstract

The present application is applicable to the technical field of relay protection of power systems, and provides a distance protection method, device, computer equipment and program product for transmission lines, the method comprising: obtaining the symmetrical component of the power system at the local end of the transmission line, obtaining the installation position of the activated protection device, determining the positive sequence voltage polarization compensation angle according to the symmetrical component, adjusting the distance protection action range according to the installation position of the protection device and the positive sequence voltage polarization compensation angle, and executing distance protection based on the phase angle of the phase-to-phase distance protection of positive sequence voltage polarization and the distance protection action range. When the grid-connected transmission line fails, the protection corresponding to the fault in the area and outside the area can be accurately identified and accurately acted.

Description

Technical Field

[0001] The present application belongs to the technical field of relay protection for electric power systems, and in particular, relates to a distance protection method, device, computer equipment and program product for a transmission line. Background Art

[0002] Positive sequence voltage polarization phase comparison distance protection is an important distance protection method for transmission lines in traditional power grids. When an ungrounded phase-to-phase fault occurs in the renewable energy grid-connected transmission line, affected by the control strategy of the renewable energy power source, if the fault current collected by the protection device is provided by the renewable energy power source, the calculation result of the positive sequence voltage polarization phase comparison distance protection will be at the action boundary, and there is a risk of protection refusal to operate in the event of an in-zone fault, and a risk of protection misoperation in the event of an out-of-zone fault. Summary of the invention

[0003] The embodiments of the present application provide a distance protection method, device, computer equipment and program product for a transmission line, which can solve the technical problem in the prior art that if the fault current collected by the protection device is provided by a new energy power source, the calculation result of the phase-comparison distance protection of the positive sequence voltage polarization will be at the action boundary, there is a risk of protection refusal to operate in the event of a fault within the zone, and there is a risk of protection malfunction in the event of a fault outside the zone.

[0004] In a first aspect, an embodiment of the present application provides a distance protection method for a transmission line, comprising:

[0005] Obtain the symmetrical components of the power system at the local end of the transmission line;

[0006] Obtain the installation location of the activated protection device;

[0007] Determining a positive sequence voltage polarization compensation angle β according to the symmetrical component;

[0008] adjusting the distance protection action range according to the installation position of the protection device and the positive sequence voltage polarization compensation angle β;

[0009] Distance protection is performed based on the phase comparison angle of the phase comparison distance protection of the positive sequence voltage polarization and the distance protection action range.

[0010] In a possible implementation of the first aspect, the symmetrical components of the power system include: three-phase voltage and three-phase current;

[0011] The step of obtaining the installation position of the activated protection device includes:

[0012] Calculating active power according to the three-phase voltage and the three-phase current;

[0013] If the active power is greater than 0, the protection device is installed on the new energy side;

[0014] If the active power is less than or equal to 0, the protection device is installed on the grid side.

[0015] In a possible implementation manner of the first aspect, the symmetrical component of the power system includes a zero-sequence current I 0 , positive sequence current I 1 and positive sequence voltage U 1 ;

[0016] The determining of the positive sequence voltage polarization compensation angle β according to the symmetrical component comprises:

[0017] Compare the zero sequence current I 0 and the positive sequence current I 1 size;

[0018] If the zero-sequence current I 0 Greater than or equal to the positive sequence current I 1 , then the positive sequence voltage polarization compensation angle β is 0;

[0019] If the zero-sequence current I 0 is less than the positive sequence current I 1 , then based on the positive sequence voltage U 1 The positive sequence voltage polarization compensation angle β is determined.

[0020] In a possible implementation manner of the first aspect, if the positive sequence voltage U 1 Less than the preset pressure threshold , then the positive sequence voltage polarization compensation angle β is 30°;

[0021] If the positive sequence voltage U 1 Greater than or equal to the preset pressure threshold , then calculate the positive sequence current I 1 and the positive sequence voltage U 1 The angle difference α;

[0022] The positive sequence voltage polarization compensation angle β is determined based on the angle difference α and the installation position of the protection device.

[0023] In a possible implementation manner of the first aspect, the installation location includes a new energy side and a grid side;

[0024] The determining the positive sequence voltage polarization compensation angle β based on the angle difference α and the installation position of the protection device comprises:

[0025] If the installation location is located on the new energy side,

[0026] but ;

[0027] If the installation location is located on the grid side,

[0028] but ;

[0029] in, is the preset action margin angle.

[0030] In a possible implementation manner of the first aspect, when the positive sequence voltage U 1 Less than the preset pressure threshold When the three-phase low voltage flag A is set to 1; when the positive sequence voltage U 1 Greater than or equal to the preset pressure threshold When the three-phase low voltage flag A is set to 0;

[0031] The adjusting the distance protection action range according to the installation position of the protection device and the positive sequence voltage polarization compensation angle β comprises:

[0032] The distance protection action range is adjusted based on the three-phase low voltage mark A, the installation position and the positive sequence voltage polarization compensation angle β.

[0033] In a possible implementation of the first aspect, the distance protection action range includes a first distance protection action range, a second distance protection action range, and a third distance protection action range; the installation location includes a new energy side and a power grid side;

[0034] The adjusting the distance protection action range based on the three-phase low voltage mark A, the installation position and the positive sequence voltage polarization compensation angle β, and the performing the distance protection based on the phase angle of the phase comparison distance protection of the positive sequence voltage polarization and the distance protection action range, include:

[0035] If the three-phase low voltage flag A is set to 1, the first distance protection action range is adjusted to: ; If the phase angle of the phase-comparison distance protection is within the first distance protection action range, the protection action is executed, otherwise the protection action is not executed;

[0036] If the three-phase low voltage flag A is set to 0 and the installation position is located on the new energy side, the second distance protection action range is adjusted to: ; If the phase angle of the phase-comparison distance protection is within the second distance protection action range, the protection action is executed, otherwise the protection action is not executed;

[0037] If the three-phase low voltage flag A is set to 0 and the installation position is located on the grid side, the third distance protection action range is adjusted to: ; If the phase comparison angle of the phase comparison distance protection is within the range of the third distance protection action, the protection action is executed, otherwise the protection action is not executed.

[0038] In a second aspect, an embodiment of the present application provides a distance protection device for a transmission line, comprising:

[0039] A symmetrical component acquisition module is used to acquire the symmetrical components of the power system at the local end of the transmission line;

[0040] An installation position acquisition module, used to acquire the installation position of the activated protection device;

[0041] A determination module, configured to determine a positive sequence voltage polarization compensation angle β according to the symmetrical component;

[0042] An adjustment module, used for adjusting the distance protection action range according to the installation position of the protection device and the positive sequence voltage polarization compensation angle β;

[0043] The execution module is used to execute distance protection based on the phase comparison angle of the phase comparison distance protection of the positive sequence voltage polarization and the distance protection action range.

[0044] In a third aspect, an embodiment of the present application provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the distance protection method for the transmission line described in any one of the first aspects above is implemented.

[0045] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the distance protection method for a transmission line described in any one of the above-mentioned first aspects is implemented.

[0046] In a fifth aspect, an embodiment of the present application provides a computer program product. When the computer program product is executed on a computer device, the computer device executes the distance protection method for a power transmission line described in any one of the first aspects above.

[0047] Compared with the prior art, the beneficial effects of the embodiments of the present application are as follows: the symmetrical components of the power system at the local end of the transmission line are obtained to calculate the positive-sequence voltage polarization compensation angle β, and the distance protection action range is adjusted according to the installation position of the protection device and the positive-sequence voltage polarization compensation angle β. When a proximal three-phase fault occurs, the action range is narrowed to avoid false operation of faults outside the zone. When the protection device is installed on the new energy side, the action boundary is increased by 270° according to the positive-sequence voltage polarization compensation angle β to ensure that the fault protection within the zone operates correctly. When the protection device is installed on the power grid side, the action boundary is increased by 90° according to the positive-sequence voltage polarization compensation angle β to ensure that the fault protection outside the zone does not operate correctly. This method can accurately identify the corresponding faults within and outside the zone when the grid-connected transmission line fails, and accurately operate, which is of great significance to ensuring the safety of the power grid.

[0048] It can be understood that the beneficial effects of the second to fifth aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0050] Figure 1 It is a flow chart of a distance protection method for a power transmission line provided in one embodiment of the present application;

[0051] Figure 2 This is a schematic diagram of a scenario of distance protection of a transmission line provided by an embodiment of the present application;

[0052] Figure 3 It is a flow chart of a distance protection method for a power transmission line provided in one embodiment of the present application;

[0053] Figure 4 It is a structural schematic diagram of a distance protection device for a transmission line provided in an embodiment of the present application;

[0054] Figure 5 It is a schematic diagram of the structure of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0055] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0056] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0057] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0058] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0059] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0060] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0061] In order to optimize the control characteristics of renewable energy power generation and improve the ability of renewable energy power generation to stay off the grid during power grid faults, renewable energy power generation control strategies are usually set with negative sequence suppression strategies and low voltage ride-through strategies. When a power grid fault occurs and the voltage drops, if the grid-connected bus voltage does not drop much, renewable energy power generation equipment may only output active power (i.e., power that actually does work) and will not provide reactive power (power used to maintain voltage levels). Therefore, during a fault, the power supply characteristics of renewable energy are affected by the control strategy, which is quite different from the fault characteristics of traditional power grids.

[0062] The phase-comparison distance protection of positive sequence voltage polarization is one of the important distance protections for transmission lines in traditional power grids. It determines the location of the fault by comparing the phase difference between the operating voltage and polarization voltage of the distance protection relay. The corresponding action range of this distance protection is that when the phase-comparison angle is between 90° and 270°, the protection device will act and cut off the fault line. It will not act outside the range (it can also be called non-execution of protection action).

[0063] When an ungrounded phase-to-phase fault occurs in the renewable energy grid-connected transmission line, affected by the control strategy of the renewable energy power source, if the fault current collected by the protection device is provided by the renewable energy power source, the calculation result of the phase-to-phase distance protection with positive-sequence voltage polarization will be at the action boundary. In the case of an in-zone fault, the phase-to-phase angle may be around 270°, and there is a risk of protection refusal to operate. In the case of an out-of-zone fault, the phase-to-phase angle may be around 90°, and there is a risk of protection misoperation. Therefore, the distance protection on the renewable energy side of the renewable energy grid-connected transmission line has the risk of refusal to operate, while the distance protection on the grid side has the risk of misoperation. This causes the protection device to not operate when it should, or to misoperate when it should not. The traditional phase-to-phase distance protection with positive-sequence voltage polarization is not suitable for renewable energy grid-connected transmission lines.

[0064] To this end, an embodiment of the present application provides a distance protection method suitable for new energy grid-connected transmission lines. When a grid-connected transmission line fails, the corresponding in-zone and out-of-zone faults can be accurately identified and accurately acted upon, which is of great significance for ensuring the safety of the power grid.

[0065] Figure 1 A schematic flow chart of a distance protection method for a power transmission line provided in the present application is shown.

[0066] S101, obtaining symmetrical components of the power system at the local end of the transmission line.

[0067] Among them, the symmetrical components of the power system at the line end are obtained in real time through the protection device.

[0068] Among them, the protection device (i.e. line protection device) is a device used to monitor and protect the transmission lines in the power system. It can detect the status of the line in real time to ensure that measures can be taken quickly in the event of a fault, such as cutting off the faulty part, to protect the safety and stability of the power grid. The protection device is usually installed at both ends of the transmission line, that is, the starting end and the end end of the line. The line end mentioned here refers to the end where the protection device is located.

[0069] Among them, the symmetrical components of the power system can also be called sequence components, which are used to describe information such as voltage and current in the three-phase system. The symmetrical components of the power system include: three-phase voltage, three-phase current, positive sequence voltage U 1 , positive sequence current I 1 and zero sequence current I 0 wait.

[0070] Three-phase voltage: refers to the voltage on the three phase lines (usually A, B, and C) in the power system.

[0071] Three-phase current: refers to the current flowing through three phase wires.

[0072] Positive sequence voltage U 1 and positive sequence current I 1 : In the power system, the phase of voltage and current can be positive sequence, negative sequence or zero sequence. Positive sequence means that the phase of three-phase voltage and current is arranged in the order of A, B, C, and the phase angle differs by 120 degrees.

[0073] Zero sequence current I 0 : Refers to the sum of the currents in the three phase lines in the power system.

[0074] Among them, the three-phase voltage and three-phase current are usually calculated by full-cycle Fourier transform, and the positive sequence voltage U 1 , positive sequence current I 1 , zero sequence current I 0 It is usually calculated using the symmetrical component method, which is not limited here.

[0075] S102, obtaining the installation position of the activated protection device.

[0076] Among them, before obtaining the installation position of the activated protection device, it is necessary to first determine whether the protection device is activated. If it is activated, the installation position of the activated protection device is directly obtained, and S103 is executed; if it is not activated, the active power is calculated according to the three-phase voltage and the three-phase current. If the active power is greater than 0, the protection device is installed on the new energy side. If the active power is less than or equal to 0, the protection device is installed on the power grid side.

[0077] Among them, in the power system, under normal operating conditions, the protection device will not start, and the new energy power source is in the power generation state. Therefore, the active power calculated by the protection device on the new energy side is in the sending direction, and the active power is greater than 0; on the contrary, the grid side is receiving active power, so the active power calculated by the protection device on the grid side is in the inflow direction, and the active power is less than 0. Among them, when the active power is 0, it means that the new energy is not generating electricity, and the protection device is also installed on the grid side. That is, the direction of power flow is determined by the active power, and then the installation position of the protection device is determined. The installation positions of the protection device include the new energy side and the grid side. For details, see Figure 2 Schematic diagram of the distance protection scenario of the transmission line. Specifically:

[0078] Active power is greater than 0: It means that the power is flowing from the location of the protection device to the outside, that is, the protection device is installed on the renewable energy side. In this case, renewable energy power generation equipment (such as wind or solar power generation equipment) outputs electric energy to the grid, so the active power is positive.

[0079] Active power is less than 0: It means that power is flowing from the outside to the location of the protection device, that is, the protection device is installed on the grid side. In this case, the grid supplies power to the location of the protection device, so the active power is negative.

[0080] Active power equals 0: It means that the renewable energy is not generating electricity and there is no renewable energy power supply. When the line fails, the fault current is provided by the grid side, so it is equivalent to the grid side.

[0081] The calculation method of active power is as follows:

[0082]

[0083] in, , , is the three-phase voltage, , , is the three-phase current, , , is the three-phase power factor angle.

[0084] This directionality is crucial for the stable operation of the power system and the protection action during faults, as it determines the flow of power and the action logic of the protection device.

[0085] S103: Determine a positive-sequence voltage polarization compensation angle β according to the symmetrical component.

[0086] Among them, the positive sequence voltage polarization compensation angle β usually refers to the phase difference angle between the polarization voltage and the measured voltage when determining the protection device action conditions. This angle is used to adjust the action range of the protection device to ensure that the protection device can operate correctly when a system fault occurs. As mentioned above, when the phase angle is in the range of 90° to 270°, the protection device will operate and cut off the fault line. Outside the range, it will not operate (it can also be called no protection action).

[0087] Among them, S103 specifically includes:

[0088] Step a, comparing the zero-sequence current I 0 and the positive sequence current I 1 size.

[0089] Step b, if the zero-sequence current I 0 Greater than or equal to the positive sequence current I 1 , then the positive sequence voltage polarization compensation angle β is 0.

[0090] Among them, when the fault type of the grid-connected transmission line is a ground fault, the fault current includes the zero-sequence current I 0 , the zero-sequence fault network has nothing to do with the power supply and is not affected by the control strategy of the new energy power supply. Therefore, when the zero-sequence current I 0 When the proportion of the fault current is large, the distance protection is less affected by the control strategy of the new energy power supply, and the action characteristics of the protection can maintain correctness. 0 When the proportion of the fault current is small, the distance protection is greatly affected by the control strategy of the new energy power supply. Therefore, when the zero-sequence current I 0 Greater than or equal to the positive sequence current I 1 When the positive sequence voltage polarization compensation angle β is 0, there is no need to adjust the distance protection action range.

[0091] Step c, if the zero sequence current I 0 is less than the positive sequence current I 1 , then based on the positive sequence voltage U 1 Determine the positive sequence voltage polarization compensation angle β. Specifically:

[0092] Step c1: if the positive sequence voltage U 1 Less than the preset pressure threshold , then the positive sequence voltage polarization compensation angle β is 30°.

[0093] Among them, when the positive sequence voltage U 1 Less than the preset pressure threshold When a three-phase fault occurs near the end, the positive sequence voltage U 1The value is small and may be close to zero. To avoid inaccurate calculation of the angle difference α, the compensation angle positive sequence voltage polarization compensation angle β is fixed, and 30° is recommended.

[0094] Step c2: if the positive sequence voltage U 1 Greater than or equal to the preset pressure threshold , then calculate the positive sequence current I 1 and the positive sequence voltage U 1 angle difference α; determining the positive sequence voltage polarization compensation angle β based on the angle difference α and the installation position of the protection device.

[0095] in, .

[0096] Wherein, if the installation location is located on the new energy side,

[0097] but .

[0098] If the installation location is located on the grid side,

[0099] but .

[0100] in, is the preset action margin angle. . Indicates the angle of the vector. Used to determine whether the three-phase voltages are all low voltages, that is, a three-phase fault occurs at the near end. The recommended value is 0.05 times the rated voltage.

[0101] It should be noted that the above is the calculation method of the positive sequence voltage polarization compensation angle β, but the positive sequence voltage polarization compensation angle β is also subject to restrictions. 0 and the preset zero-sequence current starting threshold value I 0set , further limiting the range of the positive sequence voltage polarization compensation angle β. 0 Greater than the zero-sequence current starting threshold I 0set , the maximum value of the positive-sequence voltage polarization compensation angle β is limited to 20, otherwise the maximum value of the positive-sequence voltage polarization compensation angle β is limited to 45.

[0102] S104: adjusting the distance protection action range according to the installation position of the protection device and the positive sequence voltage polarization compensation angle β.

[0103] In step c1 above, if the zero-sequence current I 0 Greater than the positive sequence current I 1 , when the positive sequence voltage U 1Less than the preset pressure threshold , the three-phase low voltage flag A is set to 1. In step c2, when the positive sequence voltage U 1 Greater than or equal to the preset pressure threshold When the three-phase low voltage flag A is set to 0.

[0104] In an optional embodiment, the distance protection action range is adjusted based on the three-phase low voltage mark A, the installation position and the positive sequence voltage polarization compensation angle β.

[0105] S105, performing distance protection based on the phase comparison angle of the phase comparison distance protection of the positive sequence voltage polarization and the distance protection action range. The distance protection action range includes a first distance protection action range, a second distance protection action range and a third distance protection action range.

[0106] Combination Figure 3 The process of executing distance protection is described. If the three-phase low voltage flag A is set to 1, the first distance protection action range is adjusted to: If the phase angle of the phase-comparison distance protection is within the first distance protection action range, the protection action is executed, otherwise the protection action is not executed, that is, the protection does not act. Indicates that the first distance protection action range is greater than , and less than .

[0107] If the three-phase low voltage flag A is set to 0 and the installation position is located on the new energy side, the second distance protection action range is adjusted to: If the phase comparison angle of the phase comparison distance protection is within the second distance protection action range, the protection action is executed; otherwise, the protection action is not executed.

[0108] If the three-phase low voltage flag A is set to 0 and the installation position is located on the grid side, the third distance protection action range is adjusted to: ; If the phase comparison angle of the phase comparison distance protection is within the range of the third distance protection action, the protection action is executed, otherwise the protection action is not executed.

[0109] Among them, the phase angle of phase-to-phase distance protection is an important parameter in phase-to-phase distance protection, which defines the phase difference threshold for the protection device to operate. When the actual measured voltage and current phase difference reaches or exceeds this angle, the protection device will determine it as an internal fault and operate.

[0110] The calculation formula of the phase angle ang1 of the phase-comparison distance protection is:

[0111]

[0112] is the operating voltage of each phase, is the positive sequence voltage of each phase, Represents each phase, including: A, B, C, AB, BC, CA.

[0113] Among them, when calculating the single-phase working voltage of A, B, and C, When calculating the working voltage between AB, BC and CA phases, .in, Indicates the preset zero-sequence compensation coefficient constant, Indicates the preset distance protection setting.

[0114] In an embodiment of the present application, the symmetrical components of the power system at the local end of the transmission line are obtained to calculate the positive-sequence voltage polarization compensation angle β, and the distance protection action range is adjusted according to the installation position of the protection device and the positive-sequence voltage polarization compensation angle β. When a proximal three-phase fault occurs, the action range is narrowed to avoid false operation of faults outside the zone. When the protection device is installed on the new energy side, the action boundary is increased by 270° according to the positive-sequence voltage polarization compensation angle β to ensure that the fault protection within the zone operates correctly. When the protection device is installed on the power grid side, the action boundary is increased by 90° according to the positive-sequence voltage polarization compensation angle β to ensure that the fault protection outside the zone does not operate correctly. This method can accurately identify the corresponding faults within and outside the zone when the grid-connected transmission line fails, and accurately operate, which is of great significance to ensuring the safety of the power grid.

[0115] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0116] Corresponding to the distance protection method for the transmission line described in the above embodiment, Figure 4 A structural block diagram of a distance protection device for a transmission line provided in an embodiment of the present application is shown. For ease of explanation, only the parts related to the embodiment of the present application are shown.

[0117] Reference Figure 4 , the distance protection device of the transmission line includes:

[0118] A symmetrical component acquisition module is used to acquire the symmetrical components of the power system at the local end of the transmission line;

[0119] An installation position acquisition module, used to acquire the installation position of the activated protection device;

[0120] A determination module, configured to determine a positive sequence voltage polarization compensation angle β according to the symmetrical component;

[0121] An adjustment module, used for adjusting the distance protection action range according to the installation position of the protection device and the positive sequence voltage polarization compensation angle β;

[0122] The execution module is used to execute distance protection based on the phase comparison angle of the phase comparison distance protection of the positive sequence voltage polarization and the distance protection action range.

[0123] In a possible implementation, the symmetrical components of the power system include: three-phase voltage and three-phase current; an installation location acquisition module is used to:

[0124] The step of obtaining the installation position of the activated protection device includes:

[0125] Calculating active power according to the three-phase voltage and the three-phase current;

[0126] If the active power is greater than 0, the protection device is installed on the new energy side;

[0127] If the active power is less than or equal to 0, the protection device is installed on the grid side.

[0128] In a possible implementation, the symmetrical components of the power system include the zero-sequence current I 0 , positive sequence current I 1 and positive sequence voltage U 1 ; Determine the module for:

[0129] Compare the zero sequence current I 0 and the positive sequence current I 1 size;

[0130] If the zero-sequence current I 0 Greater than or equal to the positive sequence current I 1 , then the positive sequence voltage polarization compensation angle β is 0;

[0131] If the zero-sequence current I 0 is less than the positive sequence current I 1 , then based on the positive sequence voltage U 1 The positive sequence voltage polarization compensation angle β is determined.

[0132] In a possible implementation, a module is determined to:

[0133] If the positive sequence voltage U 1 Less than the preset pressure threshold , then the positive sequence voltage polarization compensation angle β is 30°;

[0134] If the positive sequence voltage U 1 Greater than or equal to the preset pressure threshold , then calculate the positive sequence current I1 and the positive sequence voltage U 1 The angle difference α;

[0135] The positive sequence voltage polarization compensation angle β is determined based on the angle difference α and the installation position of the protection device.

[0136] In a possible implementation, the installation location includes a new energy side and a grid side; and a determination module is used to:

[0137] If the installation location is located on the new energy side,

[0138] but ;

[0139] If the installation location is located on the grid side,

[0140] but ;

[0141] in, is the preset action margin angle.

[0142] In a possible implementation, when the positive sequence voltage U 1 Less than the preset pressure threshold When the three-phase low voltage flag A is set to 1; when the positive sequence voltage U 1 Greater than or equal to the preset pressure threshold When the three-phase low voltage flag A is set to 0; the adjustment module is used to:

[0143] The distance protection action range is adjusted based on the three-phase low voltage mark A, the installation position and the positive sequence voltage polarization compensation angle β.

[0144] In a possible implementation, the distance protection action range includes a first distance protection action range, a second distance protection action range, and a third distance protection action range; the adjustment module and the execution module are used to:

[0145] If the three-phase low voltage flag A is set to 1, the first distance protection action range is adjusted to: ; If the phase angle of the phase-comparison distance protection is within the first distance protection action range, the protection action is executed, otherwise the protection action is not executed;

[0146] If the three-phase low voltage flag A is set to 0 and the installation position is located on the new energy side, the second distance protection action range is adjusted to: ; If the phase angle of the phase-comparison distance protection is within the second distance protection action range, the protection action is executed, otherwise the protection action is not executed;

[0147] If the three-phase low voltage flag A is set to 0 and the installation position is located on the grid side, the third distance protection action range is adjusted to: ; If the phase comparison angle of the phase comparison distance protection is within the range of the third distance protection action, the protection action is executed, otherwise the protection action is not executed.

[0148] It should be noted that the information interaction, execution process and other contents between the above-mentioned modules are based on the same concept as the method embodiment of the present application. Their specific functions and technical effects can be found in the method embodiment part and will not be repeated here.

[0149] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0150] An embodiment of the present application also provides a computer device, which includes: at least one processor, a memory, and a computer program stored in the memory and executable on the at least one processor, wherein the processor implements the steps in any of the above-mentioned method embodiments when executing the computer program.

[0151] An embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps in the above-mentioned method embodiments can be implemented.

[0152] An embodiment of the present application provides a computer program product. When the computer program product runs on a mobile terminal, the mobile terminal can implement the steps in the above-mentioned method embodiments when executing the computer program product.

[0153] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium can at least include: any entity or device that can carry the computer program code to the camera / terminal device, recording medium, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, RandomAccess Memory), electric carrier signal, telecommunication signal and software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk or an optical disk. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electric carrier signals and telecommunication signals.

[0154] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0155] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0156] In the embodiments provided in the present application, it should be understood that the disclosed devices / network equipment and methods can be implemented in other ways. For example, the device / network equipment embodiments described above are merely schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0157] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0158] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

[0159] Figure 5 This is a schematic diagram of the structure of a computer device provided in one embodiment of the present application. Figure 5 As shown, the computer device of this embodiment includes: at least one processor 20 ( Figure 5 Only one is shown in the figure), a memory 21 and a computer program 22 stored in the memory 21 and executable on the at least one processor 20, wherein the processor 20 implements the steps in any of the above-mentioned distance protection method embodiments for power transmission lines when executing the computer program 22.

[0160] The computer device may include, but is not limited to, a processor 20 and a memory 21. Those skilled in the art will appreciate that Figure 5 It is only an example of a computer device and does not constitute a limitation of the computer device. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, it may also include input and output devices, network access devices, etc.

[0161] The processor 20 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0162] In some embodiments, the memory 21 may be an internal storage unit of the computer device, such as a hard disk or memory of the computer device. In other embodiments, the memory 21 may also be an external storage device of the computer device, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the computer device. Further, the memory 21 may also include both an internal storage unit of the computer device and an external storage device. The memory 21 is used to store an operating system, an application program, a boot loader (BootLoader), data, and other programs, such as the program code of the computer program. The memory 21 may also be used to temporarily store data that has been output or is to be output.

Claims

1. A distance protection method for a transmission line, characterized in that: include: Obtain the symmetrical components of the power system at the local end of the transmission line; Obtain the installation location of the activated protection device; Determining a positive sequence voltage polarization compensation angle β according to the symmetrical component; adjusting the distance protection action range according to the installation position of the protection device and the positive sequence voltage polarization compensation angle β; Execute distance protection based on the phase angle of the phase-comparison distance protection of the positive sequence voltage polarization and the distance protection action range; The symmetrical components of the power system include: three-phase voltage and three-phase current; the installation position of the protection device to be started is obtained, including: calculating the active power according to the three-phase voltage and the three-phase current; if the active power is greater than 0, the protection device is installed on the new energy side; if the active power is less than or equal to 0, the protection device is installed on the grid side; Wherein, the symmetrical components of the power system include zero-sequence current I0, positive-sequence current I1 and positive-sequence voltage U1; the determining of the positive-sequence voltage polarization compensation angle β according to the symmetrical components includes: comparing the magnitudes of the zero-sequence current I0 and the positive-sequence current I1; if the zero-sequence current I0 is greater than or equal to the positive-sequence current I1, the positive-sequence voltage polarization compensation angle β is 0; if the zero-sequence current I0 is less than the positive-sequence current I1, the positive-sequence voltage polarization compensation angle β is determined based on the positive-sequence voltage U1; Wherein, determining the positive sequence voltage polarization compensation angle β based on the positive sequence voltage U1 includes: if the positive sequence voltage U1 is less than a preset voltage threshold value , then the positive sequence voltage polarization compensation angle β is 30°; if the positive sequence voltage U1 is greater than or equal to the preset voltage threshold value , then calculate the angle difference α between the positive sequence current I1 and the positive sequence voltage U1; determine the positive sequence voltage polarization compensation angle β based on the angle difference α and the installation position of the protection device; When the positive sequence voltage U1 is less than the preset voltage threshold value When the positive sequence voltage U1 is greater than or equal to the preset voltage threshold value, the three-phase low voltage flag A is set to 1; When the three-phase low voltage mark A is set to 0; the distance protection action range is adjusted according to the installation position of the protection device and the positive sequence voltage polarization compensation angle β, including: adjusting the distance protection action range based on the three-phase low voltage mark A, the installation position and the positive sequence voltage polarization compensation angle β; Wherein, the distance protection action range includes a first distance protection action range, a second distance protection action range and a third distance protection action range; the installation location includes a new energy side and a grid side; the distance protection action range is adjusted based on the three-phase low voltage mark A, the installation location and the positive sequence voltage polarization compensation angle β, and the distance protection is performed based on the phase angle of the phase-to-phase distance protection of the positive sequence voltage polarization and the distance protection action range, including: if the three-phase low voltage mark A is set to 1, the first distance protection action range is adjusted to: ; If the phase angle of the phase-to-phase distance protection is within the first distance protection action range, the protection action is executed, otherwise the protection action is not executed; If the three-phase low voltage flag A is set to 0 and the installation position is located on the new energy side, the second distance protection action range is adjusted to: ; If the phase angle of the phase-to-phase distance protection is within the second distance protection action range, the protection action is executed, otherwise the protection action is not executed; If the three-phase low voltage flag A is set to 0 and the installation position is located on the grid side, the third distance protection action range is adjusted to: ; If the phase comparison angle of the phase comparison distance protection is within the range of the third distance protection action, the protection action is executed, otherwise the protection action is not executed.

2. The distance protection method for a power transmission line according to claim 1, characterized in that: The installation location includes the new energy side and the grid side; The determining the positive sequence voltage polarization compensation angle β based on the angle difference α and the installation position of the protection device comprises: If the installation location is located on the new energy side, but ; If the installation location is located on the grid side, but ; in, is the preset action margin angle.

3. A distance protection device for a transmission line, characterized in that: include: A symmetrical component acquisition module is used to acquire the symmetrical components of the power system at the local end of the transmission line; An installation position acquisition module, used to acquire the installation position of the activated protection device; A determination module, configured to determine a positive sequence voltage polarization compensation angle β according to the symmetrical component; An adjustment module, used for adjusting the distance protection action range according to the installation position of the protection device and the positive sequence voltage polarization compensation angle β; An execution module, used for executing distance protection based on the phase comparison angle of the phase comparison distance protection of positive sequence voltage polarization and the distance protection action range; The symmetrical components of the power system include: three-phase voltage and three-phase current; the installation position of the protection device to be started is obtained, including: calculating the active power according to the three-phase voltage and the three-phase current; if the active power is greater than 0, the protection device is installed on the new energy side; if the active power is less than or equal to 0, the protection device is installed on the grid side; Wherein, the symmetrical components of the power system include zero-sequence current I0, positive-sequence current I1 and positive-sequence voltage U1; the determining of the positive-sequence voltage polarization compensation angle β according to the symmetrical components includes: comparing the magnitudes of the zero-sequence current I0 and the positive-sequence current I1; if the zero-sequence current I0 is greater than or equal to the positive-sequence current I1, the positive-sequence voltage polarization compensation angle β is 0; if the zero-sequence current I0 is less than the positive-sequence current I1, the positive-sequence voltage polarization compensation angle β is determined based on the positive-sequence voltage U1; Wherein, determining the positive sequence voltage polarization compensation angle β based on the positive sequence voltage U1 includes: if the positive sequence voltage U1 is less than a preset voltage threshold value , then the positive sequence voltage polarization compensation angle β is 30°; if the positive sequence voltage U1 is greater than or equal to the preset voltage threshold value , then calculate the angle difference α between the positive sequence current I1 and the positive sequence voltage U1; determine the positive sequence voltage polarization compensation angle β based on the angle difference α and the installation position of the protection device; When the positive sequence voltage U1 is less than the preset voltage threshold value When the positive sequence voltage U1 is greater than or equal to the preset voltage threshold value, the three-phase low voltage flag A is set to 1; When the three-phase low voltage mark A is set to 0; the distance protection action range is adjusted according to the installation position of the protection device and the positive sequence voltage polarization compensation angle β, including: adjusting the distance protection action range based on the three-phase low voltage mark A, the installation position and the positive sequence voltage polarization compensation angle β; Wherein, the distance protection action range includes a first distance protection action range, a second distance protection action range and a third distance protection action range; the installation location includes a new energy side and a grid side; the distance protection action range is adjusted based on the three-phase low voltage mark A, the installation location and the positive sequence voltage polarization compensation angle β, and the distance protection is performed based on the phase angle of the phase-to-phase distance protection of the positive sequence voltage polarization and the distance protection action range, including: if the three-phase low voltage mark A is set to 1, the first distance protection action range is adjusted to: ; If the phase angle of the phase-to-phase distance protection is within the first distance protection action range, the protection action is executed, otherwise the protection action is not executed; If the three-phase low voltage flag A is set to 0 and the installation position is located on the new energy side, the second distance protection action range is adjusted to: ; If the phase angle of the phase-to-phase distance protection is within the second distance protection action range, the protection action is executed, otherwise the protection action is not executed; If the three-phase low voltage flag A is set to 0 and the installation position is located on the grid side, the third distance protection action range is adjusted to: ; If the phase comparison angle of the phase comparison distance protection is within the range of the third distance protection action, the protection action is executed, otherwise the protection action is not executed.

4. A computer device, characterized in that: The method comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method according to any one of claims 1 or 2 when executing the computer program.

5. A computer program product, characterized in that When the computer program product is executed on a computer device, the computer device is caused to execute the method according to any one of claims 1 or 2.

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