Zero sequence current compensation coefficient setting method, device and medium for cable hybrid line

Abstract

This application discloses a method, device, and medium for setting the zero-sequence current compensation coefficient in a mixed cable line, belonging to the field of relay protection technology for mixed transmission lines. It includes: obtaining the power frequency impedance and length parameters of an N-segment mixed cable line; and obtaining the comprehensive zero-sequence current compensation coefficient K at each connection point of the N-segment mixed cable line. i 1≤i≤N and i is an integer; obtain the comprehensive zero-sequence compensation coefficient K of the fault point. ’ j 1≤j≤N and j is an integer; obtain the comprehensive zero-sequence current compensation coefficient K0 at the end of the operating range of the grounding distance I protection; determine K ’ j The monotonicity of K0; based on monotonicity, compare K0 with N K's. i The value of the zero-sequence current compensation coefficient K is obtained by considering the magnitude of the zero-sequence current compensation coefficient; N≥2 and N is an integer. This application improves the accuracy of the zero-sequence current compensation coefficient setting, which can ensure the reliability of the grounding distance I-stage protection operation and avoid overshooting and false operation when there is a fault at the end of a mixed line.

Description

Technical Field

[0001] This application belongs to the field of relay protection technology for hybrid transmission lines, specifically relating to a method, equipment, and medium for setting the zero-sequence current compensation coefficient for cable-coupled lines. Background Technology

[0002] Hybrid transmission lines combining overhead and cable are widely used in practical engineering. Different transmission media can be selected based on geographical constraints and site requirements, significantly improving the transmission capacity and convenience of the power system. However, existing line protection devices only offer a single K-value for zero-sequence current compensation coefficient setting. In hybrid lines, different sections have varying zero-sequence compensation coefficients, making it impossible for line protection to adjust the zero-sequence current compensation coefficient in real-time based on the actual fault location. Furthermore, setting the zero-sequence compensation coefficient based solely on the total impedance of the line may not meet the needs of actual engineering projects. This also poses a risk of maloperation due to exceeding the grounding distance threshold in section I protection, threatening system safety. Summary of the Invention

[0003] Objectives of this invention: This application provides a method for setting the zero-sequence current compensation coefficient in a mixed cable circuit. Based on the comprehensive zero-sequence current compensation coefficient of the mixed circuit, a suitable zero-sequence current compensation coefficient is selected according to the monotonicity and connection values ​​of each section of the circuit, thereby ensuring and improving the reliability of grounding distance protection. Another objective of this invention is to provide a computer device for implementing the above-mentioned setting method. A further objective of this invention is to provide a storage medium for storing a computer program that implements the above-mentioned control method.

[0004] Technical solution: This application discloses a method for setting the zero-sequence current compensation coefficient in a cable hybrid circuit, comprising the following steps:

[0005] Obtain the power frequency impedance and length parameters of each segment in a mixed N-segment cable circuit;

[0006] Based on the power frequency impedance and length parameters, obtain the comprehensive zero-sequence current compensation coefficient K for the i connection points from the first connection point to the end of the line in the N-segment cable hybrid line. i , 1≤i≤N and i is an integer;

[0007] Set the fault point and obtain the comprehensive zero-sequence compensation coefficient K of the fault point in the j-th segment of the cable-mixed circuit. ’ j , 1≤j≤N and j is an integer;

[0008] According to the K ’ j , obtain the comprehensive zero-sequence current compensation coefficient K0 when the end of the operating range of the grounding distance I protection is in the corresponding j-th segment of the cable-mixed line;

[0009] Based on the power frequency impedance and length parameters, determine the comprehensive zero-sequence compensation coefficient K. ’ j Monotonicity;

[0010] Based on the monotonicity, compare K0 with N of the K values. i The value of the zero-sequence current compensation coefficient K at the end of the operating range of the grounding distance I protection is obtained by determining the magnitude of the zero-sequence current compensation coefficient K.

[0011] Where N≥2 and N is an integer.

[0012] In some embodiments, the comprehensive zero-sequence current compensation coefficient of the first segment of the cable hybrid circuit is a constant function, that is, the comprehensive zero-sequence current compensation coefficient of the first segment is always a certain value; starting from the second segment, the comprehensive zero-sequence current compensation coefficient of each segment of the hybrid circuit exhibits monotonicity, which can be monotonically increasing or monotonically decreasing.

[0013] In some embodiments, monotonicity can be used to determine the comprehensive zero-sequence current compensation coefficient value at the connection point as the maximum or minimum value of the zero-sequence current compensation coefficient corresponding to each line segment. The maximum or minimum value can be either the maximum or the minimum value, and the monotonicity is K0 and K. i The comparison provides a theoretical basis, namely, that K0 and K can only be compared under the premise of determining monotonicity. i The comparison is used to determine the setting value of the zero-sequence current compensation coefficient.

[0014] In some embodiments, the power frequency impedance and length parameters include the positive sequence impedance per unit length of each line segment, the zero sequence impedance per unit length of each line segment, and the length of each line segment.

[0015] In some embodiments, the comprehensive zero-sequence current compensation coefficient K i The acquisition process is as follows:

[0016] ;

[0017] In the formula, Z i0 Z is the zero-sequence impedance per unit length of the i-th line segment. i1 Let L be the positive sequence impedance per unit length of the i-th line segment. i Let be the length of the i-th segment of the line.

[0018] In some embodiments, the comprehensive zero-sequence compensation coefficient K ’ j The acquisition process is as follows:

[0019] ;

[0020] In the formula, Z j0 Z is the zero-sequence impedance per unit length of the j-th line segment.j1 Let L be the positive sequence impedance per unit length of the j-th line segment. j Let L be the length of the j-th line segment. F The distance between the fault point and the beginning of the N-segment cable hybrid line is given.

[0021] In some embodiments, the process of obtaining the comprehensive zero-sequence current compensation coefficient K0 is as follows:

[0022] When the end of the operating range of the grounding distance protection section I is located in the j-th line segment, K0=K ’ j .

[0023] In some embodiments, the determination of the comprehensive zero-order compensation coefficient K ’ j The monotonicity specifically includes:

[0024] When j=1, the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j It is a constant;

[0025] When 2≤j≤N and j is odd

[0026] like Then the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j It shows a monotonically decreasing trend;

[0027] like Then the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j It shows a monotonically increasing trend;

[0028] like Then the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j The comprehensive zero-sequence compensation coefficient K with the (j-1)th segment of the line ’ j-1 same;

[0029] When 2≤j≤N and j is even

[0030] like Then the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j It shows a monotonically increasing trend;

[0031] like Then the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j It shows a monotonically decreasing trend;

[0032] like Then the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j The comprehensive zero-sequence compensation coefficient K with the (j-1)th segment of the line ’ j-1 same;

[0033] In the formula, Z j0 Z is the zero-sequence impedance per unit length of the j-th line segment. j1 Let L be the positive sequence impedance per unit length of the j-th line segment. j Let be the length of the j-th segment of the line.

[0034] In some embodiments,

[0035] When the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j The coefficient K of the comprehensive zero-sequence current at the j-th connection point is monotonically increasing. j The maximum value of the comprehensive zero-sequence compensation coefficient of the j-th line segment;

[0036] When the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j The zero-sequence current compensation coefficient K at the j-th connection point exhibits a monotonically decreasing trend. j It is the minimum value of the comprehensive zero-sequence compensation coefficient of the j-th line segment.

[0037] In some embodiments,

[0038] When the operating range of the grounding distance protection section I ends in the j-th line segment and j=1, the zero-sequence current compensation coefficient setting value K is: ;

[0039] When the operating range of the grounding distance protection section I ends in the j-th line segment and 2≤j<N,

[0040] If each segment from segment j to segment N satisfies monotonicity, and includes a segment that remains constant, then the zero-sequence current compensation coefficient setting value K is: ;

[0041] If any line segment from segment j to segment N does not satisfy monotonicity, then the value of the zero-sequence current compensation coefficient setting K is: ;

[0042] When the operating range of the grounding distance protection section I ends in the j-th line segment and j=N

[0043] like Then the zero-sequence current compensation coefficient setting value K is K0;

[0044] like The zero-sequence current compensation coefficient setting value K is then set to K. N .

[0045] In some embodiments, the case of a line segment remaining constant specifically refers to the case where the comprehensive zero-sequence compensation coefficient of a certain line segment is always a constant value.

[0046] In some embodiments, when N=3, the following steps are included:

[0047] Obtain the power frequency impedance and length parameters of the first, second, and third segments of a three-segment cable hybrid circuit;

[0048] Obtain the comprehensive zero-sequence current compensation coefficient K1 at the first connection point, the comprehensive zero-sequence current compensation coefficient K2 at the second connection point, and the comprehensive zero-sequence current compensation coefficient K3 at the end of the line in the three-segment cable hybrid line.

[0049] Set the fault point, and obtain the comprehensive zero-sequence compensation coefficient K of the fault point in the first segment of the line. ’ 1. The fault point is located at the comprehensive zero-sequence compensation coefficient K of the second section of the line. ’ 2 and the comprehensive zero-sequence compensation coefficient K of the fault point in the third section of the line. ’ 3;

[0050] According to the K ’ 1. K ’ 2 and K ’ 3. Obtain the comprehensive zero-sequence current compensation coefficient K0 at the end of the operating range of the grounding distance I protection when the corresponding cable is mixed.

[0051] Determine the comprehensive zero-sequence compensation coefficient K of the second line segment. ’ The combined zero-sequence compensation coefficient K for sections 2 and 3 ’ The monotonicity of 3;

[0052] Based on the monotonicity and by comparing the magnitudes of K0, K1, K2, and K3, the zero-sequence current compensation coefficient setting value K is obtained.

[0053] In some embodiments, if the comprehensive zero-sequence compensation coefficient K of the second line segment ’ The combined zero-sequence compensation coefficient K for sections 2 and 3 ’ 3. If there is no monotonicity, then the magnitudes of K0, K1, K2, and K3 are all equal.

[0054] In some embodiments, the process of obtaining the comprehensive zero-sequence current compensation coefficient K1 at the first connection point, the comprehensive zero-sequence current compensation coefficient K2 at the second connection point, and the comprehensive zero-sequence current compensation coefficient K3 at the end of the line is as follows:

[0055] ;

[0056] ;

[0057] ;

[0058] In the formula, Z A0 Z is the zero-sequence impedance per unit length of the first line segment. A1 L is the positive sequence impedance per unit length of the first line segment. A Z is the length of the first line segment; B0 Z is the zero-sequence impedance per unit length of the second line segment. B1 L is the positive sequence impedance per unit length of the second line segment. B Z is the length of the second segment of the line; C0 Z is the zero-sequence impedance per unit length of the third line segment. C1 L is the positive sequence impedance per unit length of the third line segment. C The length of the third segment of the line.

[0059] In some embodiments, the determination of the comprehensive zero-sequence compensation coefficient K of the second line segment ’ The monotonicity of 2 further includes:

[0060] when At that time, the comprehensive zero-sequence compensation coefficient K of the second section of the line ’ 2 shows a monotonically increasing trend;

[0061] when At that time, the comprehensive zero-sequence compensation coefficient K of the second section of the line ’ 2 shows a monotonically decreasing trend;

[0062] when At that time, the comprehensive zero-sequence compensation coefficient K of the second section of the line ’ 2. The comprehensive zero-sequence compensation coefficient K of the first section of the line ’ 1. Same;

[0063] In the formula, Z A0 Z is the zero-sequence impedance per unit length of the first line segment. A1 L is the positive sequence impedance per unit length of the first line segment. A Z is the length of the first line segment; B0 Z is the zero-sequence impedance per unit length of the second line segment. B1 This is the positive sequence impedance per unit length of the second line segment.

[0064] In some embodiments, when When the maximum and minimum values ​​are equal, monotonicity does not need to be considered.

[0065] In some embodiments,

[0066] When the comprehensive zero-sequence compensation coefficient K of the second segment of the line ’ 2 increases monotonically, and the comprehensive zero-sequence current compensation coefficient K2 at the second connection point is the maximum value of the comprehensive zero-sequence compensation coefficient of the second line segment;

[0067] When the comprehensive zero-sequence compensation coefficient K of the second segment of the line ’ 2 shows a monotonically decreasing trend, and the comprehensive zero-sequence current compensation coefficient K2 at the second connection point is the minimum value of the comprehensive zero-sequence compensation coefficient of the second line segment.

[0068] In some embodiments, the determination of the comprehensive zero-sequence compensation coefficient K of the third line segment ’ The monotonicity of 3 further includes:

[0069] when At that time, the comprehensive zero-sequence compensation coefficient K of the third segment of the line ’ 3 shows a monotonically decreasing trend;

[0070] when At that time, the comprehensive zero-sequence compensation coefficient K of the third segment of the line ’ 3 shows a monotonically increasing trend;

[0071] when At that time, the comprehensive zero-sequence compensation coefficient K of the third segment of the line ’ 3. The comprehensive zero-sequence compensation coefficient K of the second section of the line ’ 2. Same;

[0072] In the formula, Z A0 Z is the zero-sequence impedance per unit length of the first line segment. A1 L is the positive sequence impedance per unit length of the first line segment. A Z is the length of the first line segment; B0 Z is the zero-sequence impedance per unit length of the second line segment. B1 L is the positive sequence impedance per unit length of the second line segment. B Z is the length of the second segment of the line; C0 Z is the zero-sequence impedance per unit length of the third line segment. C1 L is the positive sequence impedance per unit length of the third line segment. C The length of the third segment of the line.

[0073] In some embodiments,

[0074] When the comprehensive zero-sequence compensation coefficient K of the third segment of the line’ 3 increases monotonically, and the comprehensive zero-sequence current compensation coefficient K3 at the end of the line is the maximum value of the comprehensive zero-sequence compensation coefficient of the third section of the line;

[0075] When the comprehensive zero-sequence compensation coefficient K of the third segment of the line ’ 3. The comprehensive zero-sequence current compensation coefficient K3 at the end of the line is the minimum value of the comprehensive zero-sequence compensation coefficient of the third section of the line.

[0076] when When the maximum and minimum values ​​are equal, monotonicity does not need to be considered.

[0077] In some embodiments, the fault point is in the comprehensive zero-sequence compensation coefficient K of the first line segment. ’ 1. The fault point is located at the comprehensive zero-sequence compensation coefficient K of the second section of the line. ’ 2 and the comprehensive zero-sequence compensation coefficient K of the fault point in the third section of the line. ’ The process of obtaining 3 is as follows:

[0078] Determine the length L of the first line segment. A The length L of the second line segment B The total length of the combined circuit with the three cable segments is L;

[0079] The distance between the fault point and the beginning of the three-section cable hybrid line is determined to be L. F ;

[0080] when At that time, the fault point is located in the first section of the line, and the comprehensive zero-sequence compensation coefficient K ’ The calculation process for 1 is as follows: ;

[0081] when At that time, the fault point was located in the second section of the line, and the comprehensive zero-sequence compensation coefficient K ’ The calculation process for 2 is as follows: ;

[0082] when At that time, the fault point was located in the third section of the line, and the comprehensive zero-sequence compensation coefficient K ’ The calculation process for 3 is as follows:

[0083] ;

[0084] In the formula, Z A0 Z is the zero-sequence impedance per unit length of the first line segment. A1 Z is the positive sequence resistance per unit length of the first line segment; B0 Z is the zero-sequence impedance per unit length of the second line segment. B1Z is the positive sequence impedance per unit length of the second line segment; C0 Z is the zero-sequence impedance per unit length of the third line segment. C1 The positive sequence impedance per unit length of the third line segment is given.

[0085] In some embodiments, the statement based on the K ’ 1. K ’ 2 and K ’ 3. Obtain the comprehensive zero-sequence current compensation coefficient K0 at the end of the operating range of the grounding distance I protection in the corresponding cable mixed line, further including:

[0086] When the end of the operating range of the grounding distance protection section I is within the first section of the line, K0=K ’ 1;

[0087] When the end of the operating range of the grounding distance protection section I is in the second section of the line, K0=K ’ 2;

[0088] When the operating range of the grounding distance protection section I ends at the third line section, K0=K ’ 3.

[0089] In some embodiments, when the end of the operating range of the grounding distance I protection is in the first line segment, the value of the zero-sequence current compensation coefficient setting K is: .

[0090] In some embodiments, when the operating range of the grounding distance I protection ends at the second line segment, the value of the zero-sequence current compensation coefficient setting K is as follows:

[0091] (a) when hour, ;

[0092] (b) When hour, ;

[0093] (c) When hour, ;

[0094] (d) When , , , When conditions (a), (b), and (c) are not met, .

[0095] In some embodiments, when the operating range of the grounding distance I protection ends in the third line segment, the value of the zero-sequence current compensation coefficient setting value K is as follows:

[0096] (a) when hour, ;

[0097] (b) When hour, .

[0098] In some embodiments, the operating range of the grounding distance I protection is less than or equal to 80% of the total length of the cable-mixed line.

[0099] In some embodiments, the zero-sequence current compensation coefficient setting value is applicable to three-section hybrid transmission lines and two-section hybrid transmission lines. For two-section hybrid transmission lines, the third section and its corresponding connection point are not considered.

[0100] In some embodiments, the zero-sequence current compensation coefficient setting value will not exceed the operating range outside the grounding distance I protection range, while improving the accuracy of the zero-sequence current compensation coefficient. The grounding distance II and III protection can be set with improved sensitivity.

[0101] In some embodiments, this application further includes a computer device, the computer device including a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement a method for setting the zero-sequence current compensation coefficient for cable hybrid circuits.

[0102] In some embodiments, this application further includes a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of a method for setting the zero-sequence current compensation coefficient for a cable hybrid circuit.

[0103] Beneficial effects: Compared with the prior art, the zero-sequence current compensation coefficient setting method for a cable hybrid circuit of this application includes the following steps: obtaining the power frequency impedance and length parameters of each segment of the N-segment cable hybrid circuit; and obtaining the comprehensive zero-sequence current compensation coefficient K of the i-th connection points from the first connection point to the end of the line in the N-segment cable hybrid circuit based on the power frequency impedance and length parameters. i 1≤i≤N and i is an integer; set the fault point and obtain the comprehensive zero-sequence compensation coefficient K of the fault point in the j-th segment of the cable hybrid line. ’ j , 1≤j≤N and j is an integer; according to K ’ j Obtain the comprehensive zero-sequence current compensation coefficient K0 at the end of the operating range of the grounding distance I protection segment when it is in the j-th segment of the cable-mixed line; determine the comprehensive zero-sequence compensation coefficient K0 for the second to Nth segments of the cable-mixed line based on the power frequency impedance and length parameters. ’ j The monotonicity of K0; based on monotonicity, compare K0 with N K's.i The value of N is used to obtain the zero-sequence current compensation coefficient setting value K at the end of the operating range of the grounding distance protection section I; where N≥2 and N is an integer. The zero-sequence current compensation coefficient method for multi-segment hybrid lines in this application calculates the comprehensive zero-sequence current compensation coefficient for each connection point and discovers the monotonicity of the comprehensive compensation coefficient for each segment. By considering the setting point location and the monotonicity of the comprehensive zero-sequence current compensation coefficient segment, the reliability of the zero-sequence current compensation coefficient is selected and set, avoiding false tripping of the distance protection due to overrun. The method in this application is simple and clear. It can compare the zero-sequence current compensation coefficient at each connection point of the hybrid line (i.e., the maximum or minimum value of the zero-sequence current compensation coefficient for the corresponding line segment) with the comprehensive zero-sequence current compensation coefficient at the end of the protection range to select a reliable zero-sequence current compensation coefficient, thus ensuring and improving the reliability of the grounding distance protection. Attached Figure Description

[0104] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0105] Figure 1 This is a schematic flowchart of a method for setting the zero-sequence current compensation coefficient in a cable hybrid circuit according to an embodiment of this application.

[0106] Figure 2 This is a schematic flowchart of the method for setting the zero-sequence current compensation coefficient of a cable hybrid circuit when N=3 in an embodiment of this application.

[0107] Figure 3 This is a schematic diagram of the structural system of a cable hybrid circuit according to an embodiment of this application;

[0108] Figure 4 This is a schematic diagram of a hybrid circuit comprehensive zero-sequence current compensation coefficient according to an embodiment of this application. Detailed Implementation

[0109] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0110] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for mutual communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. In the description of this application, "multiple" means two or more, unless otherwise expressly and specifically limited. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features.

[0111] The following disclosure provides many different implementations or examples for carrying out different structures of this application. To simplify the disclosure of this application, the components and arrangements of specific examples are described below. Of course, these are merely examples and are not intended to limit this application.

[0112] The applicant discovered that current zero-sequence compensation coefficients for hybrid lines only consider two-stage hybrid configurations and are not applicable to three-stage hybrid lines, posing a risk of missetting. Other patents addressing zero-sequence current compensation coefficients primarily consider the impact of mutual inductance or operating mode switching between double or multi-circuit lines. There are no established procedures or standards for setting the zero-sequence current compensation coefficient in hybrid cable lines; instead, the entire length of the hybrid line is considered comprehensively. When setting the zero-sequence current compensation coefficient based on the entire length of three-stage or multi-stage hybrid lines, problems such as excessively high zero-sequence current compensation coefficients and malfunctions due to over-limit operation may occur.

[0113] Based on this, this application provides a method for setting the zero-sequence current compensation coefficient of a cable hybrid circuit to solve the above-mentioned technical problems.

[0114] A method for setting the zero-sequence current compensation coefficient in a hybrid cable circuit, see [link to relevant documentation]. Figure 1 This includes the following steps:

[0115] Obtain the power frequency impedance and length parameters of each segment in a mixed N-segment cable circuit;

[0116] Based on the power frequency impedance and length parameters, obtain the comprehensive zero-sequence current compensation coefficient K for the i connection points from the first connection point to the end of the line in an N-segment cable hybrid circuit. i , 1≤i≤N and i is an integer;

[0117] Set the fault point and obtain the comprehensive zero-sequence compensation coefficient K of the fault point in the j-th segment of the cable hybrid circuit.’ j , 1≤j≤N and j is an integer;

[0118] According to K ’ j , obtain the comprehensive zero-sequence current compensation coefficient K0 when the end of the operating range of the grounding distance I protection is in the corresponding j-th segment of the cable-mixed line;

[0119] Determine the comprehensive zero-sequence compensation coefficient K based on the power frequency impedance and length parameters. ’ j Monotonicity;

[0120] Based on monotonicity, compare K0 with N K's. i The value of the zero-sequence current compensation coefficient K at the end of the operating range of the grounding distance I protection is obtained by determining the magnitude of the zero-sequence current compensation coefficient K.

[0121] Where N≥2 and N is an integer.

[0122] In some embodiments, the power frequency impedance and length parameters include the positive sequence impedance per unit length of each line segment, the zero sequence impedance per unit length of each line segment, and the length of each line segment.

[0123] In some embodiments, the comprehensive zero-sequence current compensation coefficient K i The acquisition process is as follows:

[0124] ;

[0125] In the formula, Z i0 Z is the zero-sequence impedance per unit length of the i-th line segment. i1 Let L be the positive sequence impedance per unit length of the i-th line segment. i Let be the length of the i-th segment of the line.

[0126] In some embodiments, the comprehensive zero-sequence compensation coefficient K ’ j The acquisition process is as follows:

[0127] ;

[0128] In the formula, Z j0 Z is the zero-sequence impedance per unit length of the j-th line segment. j1 Let L be the positive sequence impedance per unit length of the j-th line segment. j Let L be the length of the j-th line segment. F This is the distance between the fault point and the beginning of the N-segment cable mixed line.

[0129] In some embodiments, the process of obtaining the comprehensive zero-sequence current compensation coefficient K0 is as follows:

[0130] When the operating range of the grounding distance protection section I ends at the j-th line segment, K0=K ’ j .

[0131] In some embodiments, the comprehensive zero-sequence compensation coefficient K is determined. ’ j The monotonicity specifically includes:

[0132] When j=1, the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j It is a constant;

[0133] When 2≤j≤N and j is odd

[0134] like Then the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j It shows a monotonically decreasing trend;

[0135] like Then the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j It shows a monotonically increasing trend;

[0136] like Then the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j The comprehensive zero-sequence compensation coefficient K with the (j-1)th segment of the line ’ j-1 same;

[0137] When 2≤j≤N and j is even

[0138] like Then the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j It shows a monotonically increasing trend;

[0139] like Then the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j It shows a monotonically decreasing trend;

[0140] like Then the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j The comprehensive zero-sequence compensation coefficient K with the (j-1)th segment of the line ’ j-1 same;

[0141] In the formula, Z j0 Z is the zero-sequence impedance per unit length of the j-th line segment. j1 Let L be the positive sequence impedance per unit length of the j-th line segment.j Let be the length of the j-th segment of the line.

[0142] In some embodiments,

[0143] When the comprehensive zero-sequence compensation coefficient K of the j-th segment of the line ’ j It exhibits a monotonically increasing trend, and the comprehensive zero-sequence current compensation coefficient K at the j-th connection point is... j The maximum value of the comprehensive zero-sequence compensation coefficient for the j-th line segment;

[0144] When the comprehensive zero-sequence compensation coefficient K of the j-th segment of the line ’ j It exhibits a monotonically decreasing trend, and the comprehensive zero-sequence current compensation coefficient K at the j-th connection point is... j This represents the minimum value of the comprehensive zero-sequence compensation coefficient for the j-th line segment.

[0145] In some embodiments,

[0146] When the operating range of the grounding distance protection section I ends in the j-th line segment and j=1, the zero-sequence current compensation coefficient setting value K is: ;

[0147] When the operating range of the grounding distance protection section I ends in the j-th line segment and 2≤j<N,

[0148] If each segment from segment j to segment N satisfies monotonicity, and includes a segment with constant characteristics, then the zero-sequence current compensation coefficient setting value K is: ;

[0149] If any line segment from segment j to segment N does not satisfy monotonicity, then the zero-sequence current compensation coefficient setting value K is: ;

[0150] When the operating range of the grounding distance protection section I ends in the j-th line segment and j=N

[0151] like Then the zero-sequence current compensation coefficient setting value K is K0;

[0152] like Then the zero-sequence current compensation coefficient setting value K is taken as K. N .

[0153] In some embodiments, the case of a line segment remaining constant specifically refers to the case where the comprehensive zero-sequence compensation coefficient of a certain line segment is always a constant value.

[0154] In some embodiments, when N=3, a method for setting the zero-sequence current compensation coefficient of a cable hybrid circuit is as follows: Figure 2 As shown, it includes the following steps:

[0155] Step 1, see Figure 3 Taking a three-section cable hybrid line as an example, the power frequency impedance and length parameters of each section of the conductor in the three-section cable hybrid line are measured to obtain the positive sequence impedance per unit length of the first section of the line. The zero-sequence impedance per unit length is , length is Similarly, the power frequency impedance and length parameters of the second section of the line are as follows: , and The parameters of the third segment are as follows: , and The total length of the three-section cable hybrid line is ;

[0156] In some embodiments, Figure 3 In a three-section cable hybrid circuit, the positive sequence impedance per unit length of the first section is: The zero-sequence impedance per unit length is , length is The parameters for the second segment of the line are as follows: , and The parameters for the third segment of the line are as follows: , and The total length is It is 150km.

[0157] Step 2: Simulate different fault location locations, calculate the comprehensive zero-sequence compensation coefficient of the hybrid line, and calculate the comprehensive zero-sequence current compensation coefficient of each connection point of the hybrid line. The comprehensive zero-sequence current compensation coefficient of the connection point is the maximum or minimum value of the zero-sequence current compensation coefficient corresponding to each line segment. Let the distance from the fault point to the beginning of the line be... And perform the following calculations:

[0158] (1) When At that time, the comprehensive zero-sequence current compensation coefficient of the first section of the line was: ;Right now, ;

[0159] (2) When At that time, the comprehensive zero-sequence current compensation coefficient of the second section of the line is ;

[0160] Right now, ;

[0161] (3) When At that time, the comprehensive zero-sequence current compensation coefficient of the third section of the line is ;

[0162] (4) Zero-sequence current compensation coefficient at the connection point between the first and second line segments ,Right now ;

[0163] Zero-sequence current compensation coefficient at the connection point between the second and third sections of the line ,Right now ;

[0164] Zero-sequence current compensation coefficient at the end of the line ,Right now .

[0165] Step 3: Determine the comprehensive zero-sequence compensation coefficient K of the second section of the line based on the power frequency impedance and length parameters. ’ The combined zero-sequence compensation coefficient K for sections 2 and 3 ’ The monotonicity of 3;

[0166] Among them, it can be obtained through calculation Therefore, the comprehensive zero-sequence compensation coefficient K of the second segment of the line ’ 2. The zero-sequence compensation coefficients show a monotonically increasing trend when the fault location is at 35km, 40km, 45km, 50km, 55km, 60km, 70km, and 80km, respectively: 0.302, 0.443, 0.525, 0.578, 0.616, 0.644, 0.683, and 0.708.

[0167] Further calculations yield the following:

[0168] Therefore, the comprehensive zero-sequence compensation coefficient K of the third segment of the line ’ 3. The zero-sequence compensation coefficients show a monotonically decreasing trend when the fault location is at 90km, 100km, 110km, 120km, 130km, 140km, and 150km, respectively, which are 0.703, 0.699, 0.696, 0.693, 0.691, 0.689, and 0.687, respectively.

[0169] In some embodiments, the maximum and minimum values ​​of the coefficients corresponding to each line segment are as follows: , , The relationship is related to the line parameters. Different line parameters result in similar monotonicity of the comprehensive zero-sequence current compensation coefficient, but the monotonicity needs to be calculated and determined based on the line parameters.

[0170] Step 4: Calculate the operating range of the grounding distance protection (section I) and the comprehensive zero-sequence compensation coefficient calculated in Step 2. , , The comprehensive zero-sequence current compensation coefficient at the end of the operating range of the grounding distance I protection is determined as follows: ;

[0171] Step 5: Based on the monotonicity of Step 3, calculate the comprehensive zero-sequence current compensation coefficient according to the protection range. Combined zero-sequence current compensation coefficient at each connection point , , The comparisons are made, and the setting value of the zero-sequence current compensation coefficient is determined as follows:

[0172] (1) When the operating range of the grounding distance protection section I ends in the first line section, the comprehensive zero-sequence current compensation coefficient is: Zero-sequence current compensation coefficient setting value min() represents the function that takes the minimum value;

[0173] (2) When the operating range of the grounding distance protection section I ends in the second line section, the comprehensive zero-sequence current compensation coefficient is: The setting value K of the zero-sequence current compensation coefficient is selected as follows:

[0174] (a) when or At that time, the zero-sequence current compensation coefficient setting value ;

[0175] (b) When At that time, the zero-sequence current compensation coefficient setting value ;

[0176] (c) When , , , When conditions (a) and (b) are not met, the zero-sequence current compensation coefficient setting value is... min() represents the function that takes the minimum value;

[0177] (3) When the operating range of the grounding distance protection section I ends at the third line section, the comprehensive zero-sequence current compensation coefficient is: The setting value K of the zero-sequence current compensation coefficient is selected as follows:

[0178] (A) When At that time, the zero-sequence current compensation coefficient setting value ;

[0179] (B) When At that time, the zero-sequence current compensation coefficient setting value .

[0180] In some embodiments, see Figure 4The distance from the end of the operating range of the grounding distance protection on the M side to the beginning of the line is L. ZD Based on the requirement that the operating range of the grounding distance protection section I is less than or equal to 80% of the total length of the cable-mixed line, let L... ZD =0.8×L=150×0.8=120km. At this time, the end of the operating range of the grounding distance protection section I is located in the third section of the line. L ZD Substitute it into the formula in step 5 (3), that is, let = And calculate the comprehensive zero-sequence current compensation coefficient at this point as follows: The calculated comprehensive zero-sequence current compensation coefficient Combined zero-sequence current compensation coefficient at each connection point , , The comparisons are made, and the setting value K of the zero-sequence current compensation coefficient is determined. Figure 4 The operating range of the intermediate grounding distance protection (section I) ends at the third section of the line. Figure 4 As can be seen from the diagram Therefore, the zero-sequence current compensation coefficient setting value .

[0181] In some embodiments, the setting method is similar when the grounding distance I protection range is in other sections of the line.

[0182] In some embodiments, the zero-sequence current compensation coefficient setting method for a cable-mixed line of this application improves the accuracy of the zero-sequence current compensation coefficient setting, ensures the reliability of the grounding distance I protection operation, and avoids it from overshooting and maloperating when there is a fault at the end of the mixed line.

[0183] In some embodiments, this application also provides a computer device, which may be a server or a terminal, including a processor, a memory, and a communication interface connected to a system bus. The processor provides the control and computational capabilities of the computer device. The memory stores a computer program, which, when executed by the processor, implements a method for setting the zero-sequence current compensation coefficient for mixed cable circuits. The memory includes a computer storage medium and internal memory. The computer storage medium is a non-volatile storage medium that stores an operating system and the computer program. The internal memory provides an environment for the operation of the operating system and the computer program. The communication interface of the computer device is used for wired or wireless communication with external terminals, such as via Wi-Fi or mobile cellular networks.

[0184] In some embodiments, all or part of the process of the zero-sequence current compensation coefficient setting method for a cable hybrid circuit according to this application can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the methods described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0185] The foregoing has provided a detailed description of the zero-sequence current compensation coefficient setting method, device, and medium for a cable hybrid circuit provided in the embodiments of this application. Specific examples have been used in this application to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for setting the zero-sequence current compensation coefficient in a hybrid cable circuit, characterized in that, Includes the following steps: Obtain the power frequency impedance and length parameters of each segment in a mixed N-segment cable circuit; Based on the power frequency impedance and length parameters, obtain the comprehensive zero-sequence current compensation coefficient K for the i connection points from the first connection point to the end of the line in the N-segment cable hybrid line. i , 1≤i≤N and i is an integer; Set the fault point and obtain the comprehensive zero-sequence compensation coefficient K of the fault point in the j-th segment of the cable-mixed circuit. ’ j , 1≤j≤N and j is an integer; According to the K ’ j , obtain the comprehensive zero-sequence current compensation coefficient K0 when the end of the operating range of the grounding distance I protection is in the corresponding j-th segment of the cable-mixed line; Based on the power frequency impedance and length parameters, determine the comprehensive zero-sequence compensation coefficient K. ’ j Monotonicity; Based on the monotonicity, compare K0 with N of the K values. i The value of the zero-sequence current compensation coefficient K at the end of the operating range of the grounding distance I protection is obtained by determining the magnitude of the zero-sequence current compensation coefficient K. Where N≥2 and N is an integer; The determination of the comprehensive zero-sequence compensation coefficient K ’ j The monotonicity specifically includes: When j=1, the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j It is a constant; When 2≤j≤N and j is odd like Then the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j It shows a monotonically decreasing trend; like Then the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j It shows a monotonically increasing trend; like Then the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j The comprehensive zero-sequence compensation coefficient K with the (j-1)th segment of the line ’ j-1 same; When 2≤j≤N and j is even like Then the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j It shows a monotonically increasing trend; like Then the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j It shows a monotonically decreasing trend; like Then the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j The comprehensive zero-sequence compensation coefficient K with the (j-1)th segment of the line ’ j-1 same; In the formula, Z j0 Z is the zero-sequence impedance per unit length of the j-th line segment. j1 Let L be the positive sequence impedance per unit length of the j-th line segment. j Let j be the length of the j-th segment of the line; When the operating range of the grounding distance protection section I ends in the j-th line segment and j=1, the zero-sequence current compensation coefficient setting value K is: ; When the operating range of the grounding distance protection section I ends in the j-th line segment and 2≤j<N, If each segment from segment j to segment N satisfies monotonicity, and includes a segment that remains constant, then the value of the zero-sequence current compensation coefficient setting K is: ; If any line segment from segment j to segment N does not satisfy monotonicity, then the value of the zero-sequence current compensation coefficient setting K is: ; When the operating range of the grounding distance protection section I ends in the j-th line segment and j=N like Then the zero-sequence current compensation coefficient setting value K is K0; like The zero-sequence current compensation coefficient setting value K is then set to K. N .

2. The method for setting the zero-sequence current compensation coefficient of a cable hybrid circuit according to claim 1, characterized in that, The power frequency impedance and length parameters include the positive sequence impedance per unit length of each line segment, the zero sequence impedance per unit length of each line segment, and the length of each line segment.

3. The method for setting the zero-sequence current compensation coefficient of a cable hybrid circuit according to claim 1, characterized in that, The comprehensive zero-sequence current compensation coefficient K i The acquisition process is as follows: ； In the formula, Z i0 Z is the zero-sequence impedance per unit length of the i-th line segment. i1 Let L be the positive sequence impedance per unit length of the i-th line segment. i Let be the length of the i-th segment of the line.

4. The method for setting the zero-sequence current compensation coefficient of a cable hybrid circuit according to claim 1, characterized in that, The comprehensive zero-sequence compensation coefficient K ’ j The acquisition process is as follows: ； In the formula, Z j0 Z is the zero-sequence impedance per unit length of the j-th line segment. j1 Let L be the positive sequence impedance per unit length of the j-th line segment. j Let L be the length of the j-th line segment. F The distance between the fault point and the beginning of the N-segment cable hybrid line is given.

5. The method for setting the zero-sequence current compensation coefficient of a cable hybrid circuit according to claim 4, characterized in that, The process for obtaining the comprehensive zero-sequence current compensation coefficient K0 is as follows: When the end of the operating range of the grounding distance protection section I is located in the j-th line segment, K0=K ’ j .

6. The method for setting the zero-sequence current compensation coefficient of a cable hybrid circuit according to claim 1, characterized in that, When the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j The coefficient K of the comprehensive zero-sequence current at the j-th connection point is monotonically increasing. j The maximum value of the comprehensive zero-sequence compensation coefficient of the j-th line segment; When the comprehensive zero-sequence compensation coefficient K of the j-th line segment ’ j The zero-sequence current compensation coefficient K at the j-th connection point exhibits a monotonically decreasing trend. j It is the minimum value of the comprehensive zero-sequence compensation coefficient of the j-th line segment.

7. A method for setting the zero-sequence current compensation coefficient in a cable hybrid circuit according to claim 1 or 2, characterized in that, When N=3, the following steps are included: Obtain the power frequency impedance and length parameters of the first, second, and third segments of a three-segment cable hybrid circuit; Obtain the comprehensive zero-sequence current compensation coefficient K1 at the first connection point, the comprehensive zero-sequence current compensation coefficient K2 at the second connection point, and the comprehensive zero-sequence current compensation coefficient K3 at the end of the line in the three-segment cable hybrid line. Set the fault point, and obtain the comprehensive zero-sequence compensation coefficient K of the fault point in the first segment of the line. ’ 1. The fault point is located at the comprehensive zero-sequence compensation coefficient K of the second section of the line. ’ 2 and the comprehensive zero-sequence compensation coefficient K of the fault point in the third section of the line. ’ 3; According to the K ’ 1. K ’ 2 and K ’ 3. Obtain the comprehensive zero-sequence current compensation coefficient K0 at the end of the operating range of the grounding distance I protection when the corresponding cable is mixed. Determine the comprehensive zero-sequence compensation coefficient K of the second line segment. ’ The combined zero-sequence compensation coefficient K for sections 2 and 3 ’ The monotonicity of 3; Based on the monotonicity and by comparing the magnitudes of K0, K1, K2, and K3, the zero-sequence current compensation coefficient setting value K is obtained.

8. The method for setting the zero-sequence current compensation coefficient of a cable hybrid circuit according to claim 7, characterized in that, The process for obtaining the comprehensive zero-sequence current compensation coefficient K1 at the first connection point, the comprehensive zero-sequence current compensation coefficient K2 at the second connection point, and the comprehensive zero-sequence current compensation coefficient K3 at the end of the line is as follows: ； ； ； In the formula, Z A0 Z is the zero-sequence impedance per unit length of the first line segment. A1 L is the positive sequence impedance per unit length of the first line segment. A Z is the length of the first line segment; B0 Z is the zero-sequence impedance per unit length of the second line segment. B1 L is the positive sequence impedance per unit length of the second line segment. B Z is the length of the second segment of the line; C0 Z is the zero-sequence impedance per unit length of the third line segment. C1 L is the positive sequence impedance per unit length of the third line segment. C The length of the third segment of the line.

9. The method for setting the zero-sequence current compensation coefficient of a cable hybrid circuit according to claim 7, characterized in that, The comprehensive zero-sequence compensation coefficient K of the second segment of the line is determined. ’ The monotonicity of 2 further includes: when At that time, the comprehensive zero-sequence compensation coefficient K of the second section of the line ’ 2 shows a monotonically increasing trend; when At that time, the comprehensive zero-sequence compensation coefficient K of the second section of the line ’ 2 shows a monotonically decreasing trend; when At that time, the comprehensive zero-sequence compensation coefficient K of the second section of the line ’ 2. The comprehensive zero-sequence compensation coefficient K of the first section of the line ’ 1. Same; In the formula, Z A0 Z is the zero-sequence impedance per unit length of the first line segment. A1 L is the positive sequence impedance per unit length of the first line segment. A Z is the length of the first line segment; B0 Z is the zero-sequence impedance per unit length of the second line segment. B1 This is the positive sequence impedance per unit length of the second line segment.

10. The method for setting the zero-sequence current compensation coefficient of a cable hybrid circuit according to claim 9, characterized in that, When the comprehensive zero-sequence compensation coefficient K of the second segment of the line ’ 2 increases monotonically, and the comprehensive zero-sequence current compensation coefficient K2 at the second connection point is the maximum value of the comprehensive zero-sequence compensation coefficient of the second line segment; When the comprehensive zero-sequence compensation coefficient K of the second segment of the line ’ 2 shows a monotonically decreasing trend, and the comprehensive zero-sequence current compensation coefficient K2 at the second connection point is the minimum value of the comprehensive zero-sequence compensation coefficient of the second line segment.

11. The method for setting the zero-sequence current compensation coefficient of a cable hybrid circuit according to claim 7, characterized in that, Determine the comprehensive zero-sequence compensation coefficient K of the third line segment. ’ The monotonicity of 3 further includes: when At that time, the comprehensive zero-sequence compensation coefficient K of the third segment of the line ’ 3 shows a monotonically decreasing trend; when At that time, the comprehensive zero-sequence compensation coefficient K of the third segment of the line ’ 3 shows a monotonically increasing trend; when At that time, the comprehensive zero-sequence compensation coefficient K of the third segment of the line ’ 3. The comprehensive zero-sequence compensation coefficient K of the second section of the line ’ 2. Same; In the formula, Z A0 Z is the zero-sequence impedance per unit length of the first line segment. A1 L is the positive sequence impedance per unit length of the first line segment. A Z is the length of the first line segment; B0 Z is the zero-sequence impedance per unit length of the second line segment. B1 L is the positive sequence impedance per unit length of the second line segment. B Z is the length of the second segment of the line; C0 Z is the zero-sequence impedance per unit length of the third line segment. C1 The positive sequence impedance per unit length of the third line segment is given.

12. The method for setting the zero-sequence current compensation coefficient of a cable hybrid circuit according to claim 11, characterized in that, When the comprehensive zero-sequence compensation coefficient K of the third segment of the line ’ 3 increases monotonically, and the comprehensive zero-sequence current compensation coefficient K3 at the end of the line is the maximum value of the comprehensive zero-sequence compensation coefficient of the third section of the line; When the comprehensive zero-sequence compensation coefficient K of the third segment of the line ’ 3. The comprehensive zero-sequence current compensation coefficient K3 at the end of the line is the minimum value of the comprehensive zero-sequence compensation coefficient of the third section of the line.

13. The method for setting the zero-sequence current compensation coefficient of a cable hybrid circuit according to claim 7, characterized in that, The fault point is located at the comprehensive zero-sequence compensation coefficient K of the first section of the line. ’ 1. The fault point is located at the comprehensive zero-sequence compensation coefficient K of the second section of the line. ’ 2 and the comprehensive zero-sequence compensation coefficient K of the fault point in the third section of the line. ’ The process of obtaining 3 is as follows: Determine the length L of the first line segment. A The length L of the second line segment B The total length of the combined circuit with the three cable segments is L; The distance between the fault point and the beginning of the three-section cable hybrid line is determined to be L. F ; when At that time, the fault point is located in the first segment of the line, and the comprehensive zero-sequence compensation coefficient K ’ The calculation process for 1 is as follows: ; when At that time, the fault point is located in the second section of the line, and the comprehensive zero-sequence compensation coefficient K ’ The calculation process for 2 is as follows: ; when At that time, the fault point is located in the third line segment, and the comprehensive zero-sequence compensation coefficient K ’ The calculation process for 3 is as follows: ； In the formula, Z A0 Z is the zero-sequence impedance per unit length of the first line segment. A1 Z is the positive sequence resistance per unit length of the first line segment; B0 Z is the zero-sequence impedance per unit length of the second line segment. B1 This is the positive sequence impedance per unit length of the second line segment; Z C0 Z is the zero-sequence impedance per unit length of the third line segment. C1 The positive sequence impedance per unit length of the third line segment is given.

14. The method for setting the zero-sequence current compensation coefficient of a cable hybrid circuit according to claim 13, characterized in that, According to the K ’ 1. K ’ 2 and K ’ 3. Obtain the comprehensive zero-sequence current compensation coefficient K0 at the end of the operating range of the grounding distance I protection in the corresponding cable mixed line, further including: When the end of the operating range of the grounding distance I protection is located at the first section of the line, K0=K ’ 1; When the end of the operating range of the grounding distance I protection is located at the second line section, K0=K ’ 2; When the end of the operating range of the grounding distance protection section I is located at the third line section, K0=K ’ 3.

15. The method for setting the zero-sequence current compensation coefficient of a cable hybrid circuit according to claim 14, characterized in that, When the operating range of the grounding distance I protection ends at the first section of the line, the zero-sequence current compensation coefficient setting value K is: .

16. The method for setting the zero-sequence current compensation coefficient of a cable hybrid circuit according to claim 14, characterized in that, When the operating range of the grounding distance protection section I ends in the second line section, the value of the zero-sequence current compensation coefficient setting value K is as follows: (a) when hour, ; (b) When hour, ; (c) When hour, ; (d) When , , , When conditions (a), (b), and (c) are not met, .

17. The method for setting the zero-sequence current compensation coefficient of a cable hybrid circuit according to claim 14, characterized in that, When the operating range of the grounding distance I protection ends at the third line segment, the value of the zero-sequence current compensation coefficient setting K is as follows: (a) when hour, ; (b) When hour, .

18. The method for setting the zero-sequence current compensation coefficient of a cable hybrid circuit according to claim 1, characterized in that, The operating range of the grounding distance I protection is less than or equal to 80% of the total length of the cable-mixed line.

19. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 18.

20. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 18.

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