Distribution network protection setting value automatic checking method based on adaptive matching

Abstract

The invention relates to a distribution network protection constant value automatic checking method based on adaptive matching. The method comprises the following steps: step 1, establishing a constant value checking rule system; 2, determining the role of a distribution network protection switch; step 3, according to the distribution network protection switch role determined in the step 2, the distribution network protection switch adaptively matches a constant value checking scheme, and a constant value checking rule of each segment of current protection in the constant value checking rule system in the step 1 corresponding to the constant value checking scheme is obtained; step 4, automatically calculating a check value by the distribution network protection switch based on the check rule of the constant value of each section of current protection obtained in the step 3; and 5, based on the check value obtained in the step 4, judging a constant value check result. According to the distribution network protection switch role and the topological structure, the corresponding constant value checking scheme and the constant value checking position are adaptively matched to carry out constant value automatic checking.

Description

Technical Field

[0001] The invention belongs to the technical field of distribution network relay protection, and relates to a distribution network protection set value automatic verification method, in particular to a distribution network protection set value automatic verification method based on adaptive matching. Background Art

[0002] With the continuous changes in the grid structure and the continuous development of the power system, the reliability of urban distribution network power supply is increasingly required. This requires the accuracy of the distribution network relay protection setting to ensure correct operation under various operating modes. Therefore, it is particularly important to regularly check the relay protection setting.

[0003] However, the existing automatic verification method for distribution network protection setting has the following defects:

[0004] 1) The distribution network relay protection settings are set offline. The setting list is executed on the relay protection device through multiple management processes, and the adaptability of the setting to the ever-changing power grid cannot be confirmed.

[0005] 2) The setting of the distribution network relay protection setting depends on the selected setting principles and working experience, and it is impossible to ensure that the setting meets the relay protection setting performance requirements such as sensitivity and selectivity at the same time.

[0006] 3) The traditional set value verification method is that all distribution network protection switches use the same set of verification methods. Only after the set value is set, the sensitivity coefficient of the final set value is calculated to verify the sensitivity. Different verification methods cannot be used according to the role of the switch to comprehensively verify the sensitivity, selectivity, reliability, and load avoidance of the set value.

[0007] Therefore, the present invention proposes a method for automatic calibration of distribution network protection settings based on adaptive matching, which can solve the above problems.

[0008] After searching, no public documents of the prior art identical or similar to the present invention were found. Summary of the invention

[0009] The purpose of the present invention is to overcome the shortcomings of the prior art and propose a method for automatic calibration of distribution network protection constants based on adaptive matching, based on which the constants meet the requirements of relay protection sensitivity, selectivity, reliability and load avoidance, and according to the roles and topological structures of distribution network protection switches, adaptively match the corresponding constant calibration schemes and constant calibration positions to perform automatic calibration of the constants.

[0010] The present invention solves the practical problem by adopting the following technical solutions:

[0011] A method for automatically checking a distribution network protection setting value based on adaptive matching comprises the following steps:

[0012] Step 1: Establish a fixed value verification rule system;

[0013] Step 2: Determine the role of the distribution network protection switch;

[0014] Step 3: According to the role of the distribution network protection switch determined in step 2, the distribution network protection switch adaptively matches the fixed value verification scheme, and obtains the fixed value verification rules of each section of current protection in the fixed value verification rule system of step 1 corresponding to the fixed value verification scheme;

[0015] Step 4: Based on the current protection value verification rules for each section obtained in step 3, the distribution network protection switch automatically calculates the verification value;

[0016] Step 5: Based on the calibration value obtained in step 4, determine the fixed value calibration result.

[0017] Moreover, the fixed value verification rule system of step 1 includes: verification position, verification formula, comparison symbol and verification type;

[0018] The check positions include: the switch, the upper switch, the lower switch, the end of the line, the exit of the line, the back of the line, the end of the adjacent line, the low-voltage side of the adjacent transformer, the low-voltage side of the connected transformer and the end of the longest line, etc.

[0019] Among them, the switch calibration position corresponds to the parameter variable, the upper switch and the lower switch correspond to the fixed value variable, and the other calibration positions correspond to the fault variable;

[0020] Among them, the calibration formula is a digital calculation formula based on the combination of various fault variables, parameter variables, fixed value variables, and conventional variables, and a calibration value can be calculated by mathematics;

[0021] Among them, the comparison operators are divided into three types: greater than or equal to, less than or equal to, and equal to.

[0022] Among them, the verification type corresponds to the performance requirements of relay protection settings, which are divided into selectivity, sensitivity, load avoidance, and reliability.

[0023] Moreover, the distribution network protection switch role in step 2 is a combination of the branch level and the protection level;

[0024] The branch levels are divided into: main line, first-level branch and second-level branch.

[0025] The protection levels are divided into: first level, second level, third level, and fourth level, among which the substation outgoing line switch is the first level protection.

[0026] The constant value verification scheme can set the verification rules for each section of constant values ​​as well as the applicable branch level and protection level.

[0027] Moreover, the specific method of step 3 is:

[0028] The distribution network protection switch automatically matches the constant value verification scheme according to its own switch role. When the switch has both branch level and protection level information, it automatically matches the constant value verification scheme that is suitable for both. When the switch only has branch level or protection level information, it automatically matches the constant value verification scheme that is only applicable to the branch level or protection level. The distribution network protection switch obtains the constant value verification rules for each section of current protection corresponding to the constant value verification scheme according to the matched constant value verification scheme.

[0029] Moreover, the specific method of step 4 is:

[0030] The distribution network protection switch matches the corresponding fault variable, fixed value variable, and parameter variable according to the calibration position of the calibration rule, calculates the value of the fault variable or obtains the value of the parameter variable and fixed value variable, matches the values ​​of the parameter variable, fixed value variable, fault variable and conventional variable to the variables of the calibration formula, and then calculates the calibration value through the digital formula.

[0031] Moreover, the specific method of step 5 is:

[0032] Compare the setting value of the distribution network protection switch with the calibration value to see if they meet the comparison relationship. If they do, the calibration of the set value passes. If they do not, the calibration of this set value fails. The calibration results of each calibration rule are classified and counted by calibration type. If all calibration rules of each calibration type pass, this set value meets this calibration type. Otherwise, an alarm is issued for this calibration type.

[0033] The objective function of the calibration result of a certain calibration type is expressed as:

[0034] E=bool(M1,M2,……Mn)

[0035] Among them, M is the verification result of each verification rule, and E is the verification result of this verification type;

[0036] When every check rule of a certain check type is checked and satisfied, the check type is checked and satisfied; that is, the values ​​of M1~Mn are true. If only one of the values ​​of M1~Mn is false, the check type is not checked and satisfied.

[0037] Advantages and beneficial effects of the present invention:

[0038] 1. The present invention proposes an automatic calibration method for distribution network protection constants based on adaptive matching. For the calibration of distribution network switch relay protection constants, the switch role adaptive matching constant calibration scheme is used to obtain the calibration rules, so as to realize the accurate calibration of the switch constants; the fault variables, parameter variables and constant value variables of the distribution network protection switch are adaptively matched by the calibration position defined by the calibration rule, and the calibration value of the calibration rule is obtained by the automatic calculation formula, so as to realize the automatic identification and automatic calculation of the calibration rule; the calibration result of the calibration rule is automatically judged by comparing the calibration rule, and the calibration results are classified and counted according to the calibration type, so as to finally obtain the constant value calibration result of the distribution network protection switch, so as to realize the automatic judgment and automatic statistics of the calibration result.

[0039] 2. The present invention proposes a method for establishing a fixed value verification rule system, and formulates computer-recognizable verification rules by defining the verification position, verification formula, comparison symbol, and verification type of the verification rule. Each fixed value item can establish verification rules including multiple verification types such as sensitivity, selectivity, load avoidance, reliability, etc., which can ensure that the fixed value meets the relay protection fixed value performance requirements such as sensitivity and selectivity at the same time.

[0040] 2. The present invention proposes a method for a constant value verification scheme based on adaptive matching of distribution network switch roles, which automatically matches the applicable branch level and applicable protection level of the verification scheme according to the branch level and protection level of the switch, thereby achieving a comprehensive constant value verification of the protection switch using the most suitable constant value verification scheme.

[0041] 3. The present invention proposes a method for automatic calibration calculation of relay protection fixed values ​​of distribution network protection switches, which automatically calculates the calibration value of the calibration rule by adaptively matching the fault variable, fixed value variable and parameter variable of the distribution network protection switch through the calibration rule, thus realizing automatic identification of the calibration rule and automatic and rapid calculation of the calibration value.

[0042] 4. The present invention proposes an automatic determination method for fixed value calibration results, which automatically determines the calibration results of the calibration rules by comparing them, classifies and counts the calibration results according to the calibration type, and automatically obtains the total calibration result of the calibration type, thereby realizing automatic determination of the calibration results.

[0043] 5. The present invention is applicable to the automatic calibration of the fixed values ​​of distribution network protection switches; when the distribution network topology, operation method, and equipment parameters change, the existing fixed values ​​are automatically calibrated to ensure the adaptability of the distribution network relay protection fixed values ​​to the power grid. The calibration process of the present invention has a high level of automation, the calibration rule calculation speed is fast, and the calculation results are accurate; the present invention automatically determines the calibration results of the calibration rules, and statistically calculates the calibration results according to the calibration type, and the final calibration results of the fixed values ​​are accurate; the fixed value calibration results of the present invention are accurate, and the entire calibration process does not require manual intervention, which can improve the efficiency of the fixed value calibration work and ensure the accuracy of the distribution network relay protection fixed values; BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a flow chart of the automatic value checking process of the present invention;

[0045] Figure 2 It is a schematic diagram of the verification rule system of the present invention;

[0046] Figure 3 An example diagram of the switch role of the present invention in a power distribution topology;

[0047] Figure 4 Schematic diagram of the switch matching constant value verification scheme in a specific implementation manner of the present invention. DETAILED DESCRIPTION

[0048] The embodiments of the present invention are further described in detail below with reference to the accompanying drawings:

[0049] A method for automatic calibration of distribution network protection settings based on adaptive matching, such as Figure 1 As shown, the following steps are included:

[0050] Step 1: Establish a fixed value verification rule system;

[0051] like Figure 2 As shown, the fixed value verification rule system of step 1 includes: verification position, verification formula, comparison symbol and verification type;

[0052] The check positions include: the switch, the upper switch, the lower switch, the end of the line, the exit of the line, the back of the line, the end of the adjacent line, the low-voltage side of the adjacent transformer, the low-voltage side of the connected transformer and the end of the longest line, etc.

[0053] Among them, the switch calibration position corresponds to the parameter variable, the upper switch and the lower switch correspond to the fixed value variable, and the other calibration positions correspond to the fault variable;

[0054] Among them, the calibration formula is a digital calculation formula based on the combination of various fault variables, parameter variables, fixed value variables, and conventional variables, and a calibration value can be calculated by mathematics;

[0055] Among them, the comparison operators are divided into three types: greater than or equal to, less than or equal to, and equal to.

[0056] Among them, the verification type corresponds to the performance requirements of relay protection settings, which are divided into selectivity, sensitivity, load avoidance, and reliability (reliable fault avoidance).

[0057] Step 2: Determine the role of the distribution network protection switch;

[0058] The role of the distribution network protection switch in step 2 is a combination of the branch level and the protection level;

[0059] The branch levels are divided into: main line, first-level branch and second-level branch.

[0060] The protection levels are divided into: first level, second level, third level, and fourth level, among which the substation outgoing line switch is the first level protection.

[0061] The setting value verification scheme can set the verification rules for each section of the setting value and the applicable branch level and protection level. Figure 3 shown.

[0062] Step 3: According to the role of the distribution network protection switch determined in step 2, the distribution network protection switch adaptively matches the fixed value verification scheme, and obtains the fixed value verification rules of each section of current protection in the fixed value verification rule system of step 1 corresponding to the fixed value verification scheme;

[0063] The specific method of step 3 is:

[0064] The distribution network protection switch automatically matches the constant value verification scheme according to its own switch role. When the switch has both branch level and protection level information, it automatically matches the constant value verification scheme that is suitable for both. When the switch only has branch level or protection level information, it automatically matches the constant value verification scheme that is only applicable to the branch level or protection level. The distribution network protection switch obtains the constant value verification rules for each section of current protection corresponding to the constant value verification scheme according to the matched constant value verification scheme.

[0065] Step 4: Based on the current protection value verification rules for each section obtained in step 3, the distribution network protection switch automatically calculates the verification value;

[0066] The specific method of step 4 is:

[0067] The distribution network protection switch matches the corresponding fault variable, fixed value variable, and parameter variable according to the calibration position of the calibration rule, calculates the value of the fault variable or obtains the value of the parameter variable and fixed value variable, matches the values ​​of the parameter variable, fixed value variable, fault variable and conventional variable to the variables of the calibration formula, and then calculates the calibration value through the digital formula.

[0068] Step 5: Based on the calibration value obtained in step 4, determine the fixed value calibration result;

[0069] The specific method of step 5 is:

[0070] Compare the setting value of the distribution network protection switch with the calibration value to see if they meet the comparison relationship. If they do, the calibration of the set value passes. If they do not, the calibration of this set value fails. The calibration results of each calibration rule are classified and counted by calibration type. If all calibration rules of each calibration type pass, this set value meets this calibration type. Otherwise, an alarm is issued for this calibration type.

[0071] The objective function of the calibration result of a certain calibration type is expressed as:

[0072] E=bool(M1,M2,……Mn)

[0073] Among them, M is the verification result of each verification rule, and E is the verification result of this verification type;

[0074] When every check rule of a certain check type is checked and satisfied, the check type is checked and satisfied; that is, the values ​​of M1~Mn are true. If only one of the values ​​of M1~Mn is false, the check type is not checked and satisfied.

[0075] Embodiment 1:

[0076] The present invention proposes a method for automatically checking the setting value of distribution network protection based on adaptive matching. Figure 1 The overcurrent protection implementation process of the distribution network protection switch of the present invention is further described in detail.

[0077] 1) Verification rule definition

[0078] The definition of the distribution network switch overcurrent protection verification rules is as follows.

[0079] Verification rule 1: Verify the sensitivity at the end of this line

[0080] Verification location: end of this line

[0081] Verification formula: Idmin / 1.5Idmin is the fault variable: the minimum short-circuit current of the fault at the end of this line

[0082] Comparison operator: ≤

[0083] Calibration type: Sensitivity

[0084] Verification rule 2: Verify the fault sensitivity at the end of adjacent lines

[0085] Verification location: End of adjacent line

[0086] Verification formula: Ixdmin / 1.2Idmin is the fault variable: the minimum short-circuit current of the adjacent line end fault

[0087] Comparison operator: ≤

[0088] Verification type: Sensitivity verification Rule 3: Verify coordination with the downstream switch overcurrent protection

[0089] Check position: Lower switch

[0090] Verification formula: 1.1*Idz3 Idz3 is a fixed value variable: the lower switch overcurrent protection fixed value

[0091] Comparison operator: ≥

[0092] Check type: Selective

[0093] Verification rule 4: Verify the primary value of the CT current

[0094] Check position: This switch

[0095] Calibration formula: 1.1*Ict1 Ict1 is parameter variable: CT primary value

[0096] Comparison operator: ≥

[0097] Check type: load avoidance

[0098] Verification rule 5: Verify to avoid maximum load current

[0099] Check position: This switch

[0100] Verification formula: 1.2*Ifhmax Ifhmax is a parameter variable: maximum load current

[0101] Comparison operator: ≥

[0102] Check type: load avoidance

[0103] 2) Develop a set value verification plan and appropriate switch roles

[0104] A fixed value verification scheme A is formulated to adapt to the second-level switches of the main line. The corresponding verification rules are Rule 1, Rule 2, Rule 3, and Rule 5. A total of three types of verifications are conducted: sensitivity, selectivity, and load avoidance.

[0105] 3) Switch adaptive setting value verification scheme

[0106] like Figure 4 As shown in the distribution network wiring diagram, the 102 switch is the second-level protection of the trunk level, and automatically matches the constant value verification scheme A.

[0107] 4) Distribution network protection switch automatically calculates and verifies the set value

[0108] The setting value of the overcurrent protection of the distribution network 102 switch is 600A. The corresponding fault variables, fixed value variables, and parameter variables are matched according to the verification position of the verification rule, and the values ​​of the fault variables and the parameter variables and fixed value variables are calculated as shown in the following table.

[0109] Check position Variable Types Variable Description Variable Value End of this line Fault variables Minimum short-circuit current of fault at the end of this line 1080 Adjacent line end Fault variables Minimum short-circuit current of adjacent end fault 696 Lower switch Fixed value variables Lower switch overcurrent protection setting 400 This switch Parameter variables Maximum load current 500

[0110] Match the values ​​of parameter variables, set value variables, fault variables and conventional variables to the variables in the calibration formula, and then calculate the calibration value through the digital formula. The overcurrent protection setting value of the distribution network protection switch is 600A. After comparison and judgment, the calibration results of each calibration rule are shown in the following table.

[0111] Rule number Calculation formula Check value Verification results Rule 1 ≤Idmin / 1.5 720 satisfy Rule 2 ≤Ixdmin / 1.2 580 Dissatisfied Rule 3 ≥1.1*Idz3 440 satisfy Rule 5 ≥1.2*Ifhmax 600 satisfy

[0112] 5) Determination of the results of the calibration of the distribution network protection switch setting

[0113] The verification results of each verification rule are classified and counted according to the verification type. When all the verification rules of each verification type are passed, this set value satisfies this verification type, otherwise, an alarm is issued for this verification type. The verification results of the overcurrent protection of the distribution network 102 switch are shown in the following table

[0114]

[0115] The present invention proposes a method for automatic calibration of distribution network protection constants based on adaptive matching, which satisfies the requirements of relay protection sensitivity, selectivity, reliability and load avoidance based on the constant values, and performs automatic calibration of the constant values ​​by adaptively matching the corresponding constant value calibration schemes and constant value calibration positions according to the roles and topological structures of distribution network protection switches.

[0116] Compared with the existing relay protection setting value verification technology, the innovation of the present invention lies in:

[0117] 1) The present invention adaptively matches the set value verification scheme according to the role of the distribution network protection switch, obtains the corresponding verification rules, and realizes that the protection switch adopts the most suitable set value verification scheme for comprehensive set value verification, which can ensure that the set value simultaneously meets the relay protection set value performance requirements such as sensitivity and selectivity.

[0118] 2) The present invention adaptively matches the fault variables, fixed value variables and parameter variables of the distribution network protection switch according to the fault location of the calibration rule, realizes the automatic identification of the calibration rule, and improves the automation level of the fixed value calibration work, wherein the fault variables and parameter variables are the current variables corresponding to the distribution network topology, operation mode and equipment parameters. The fixed value calibration is a comprehensive calibration of the fixed value performance of the current power grid to ensure the adaptability of the fixed value to the power grid.

[0119] 3) The present invention automatically calculates the calibration value according to the calibration formula, and determines whether the calibration is passed according to the comparison symbol, thereby realizing automatic recognition of the calibration result and improving the accuracy of the fixed value calibration result.

[0120] 4) The present invention automatically classifies and counts the verification results of all verification rules according to the verification type, and extracts the fixed value verification conclusion according to the fixed value performance requirements of the relay protection, thus meeting the requirements of the actual work of the relay protection for the fixed value performance.

[0121] 5) The present invention can improve the accuracy of relay protection settings in distribution networks. Its basic principle can be extended to the verification of relay protection settings for high-voltage lines, transformers, busbars and other equipment. It has the advantages of being easy to expand and promote and having rich application scenarios.

[0122] It should be emphasized that the embodiments of the present invention are illustrative rather than restrictive. Therefore, the present invention includes but is not limited to the embodiments described in the specific implementation modes. Any other implementation modes derived by those skilled in the art based on the technical solutions of the present invention also fall within the scope of protection of the present invention.

Claims

1. A method for automatic verification of distribution network protection setting values ​​based on adaptive matching, characterized in that: The following steps are involved: Step 1: Establish a fixed value verification rule system; Step 2: Determine the role of the distribution network protection switch; Step 3: According to the role of the distribution network protection switch determined in step 2, the distribution network protection switch adaptively matches the fixed value verification scheme, and obtains the fixed value verification rules of each section of current protection in the fixed value verification rule system of step 1 corresponding to the fixed value verification scheme; Step 4: Based on the current protection value verification rules for each section obtained in step 3, the distribution network protection switch automatically calculates the verification value; Step 5: Based on the calibration value obtained in step 4, determine the fixed value calibration result.

2. According to claim 1, a method for automatic verification of distribution network protection setting values ​​based on adaptive matching is characterized in that: The fixed value verification rule system of step 1 includes: verification position, verification formula, comparison symbol and verification type; The check positions include: the switch, the upper switch, the lower switch, the end of the line, the exit of the line, the back of the line, the end of the adjacent line, the low-voltage side of the adjacent transformer, the low-voltage side of the connected transformer and the end of the longest line, etc. Among them, the switch calibration position corresponds to the parameter variable, the upper switch and the lower switch correspond to the fixed value variable, and the other calibration positions correspond to the fault variable; Among them, the calibration formula is a digital calculation formula based on the combination of various fault variables, parameter variables, fixed value variables, and conventional variables, and a calibration value can be calculated by mathematics; Among them, the comparison operators are divided into three types: greater than or equal to, less than or equal to, and equal to; Among them, the verification type corresponds to the performance requirements of relay protection settings, which are divided into selectivity, sensitivity, load avoidance, and reliability.

3. According to the method of automatic calibration of distribution network protection setting value based on adaptive matching according to claim 1, it is characterized by: The distribution network protection switch role in step 2 is a combination of the branch level and the protection level; The branch levels are divided into: trunk line, primary branch and secondary branch; The protection levels are divided into: first level, second level, third level, and fourth level, among which the substation outgoing line switch is the first level protection; The constant value verification scheme can set the verification rules for each section of constant values ​​as well as the applicable branch level and protection level.

4. The method for automatic verification of distribution network protection setting values ​​based on adaptive matching according to claim 1 is characterized in that: The specific method of step 3 is: The distribution network protection switch automatically matches the constant value verification scheme according to its own switch role. When the switch has both branch level and protection level information, it automatically matches the constant value verification scheme that is suitable for both. When the switch only has branch level or protection level information, it automatically matches the constant value verification scheme that is only applicable to the branch level or protection level. The distribution network protection switch obtains the constant value verification rules for each section of current protection corresponding to the constant value verification scheme according to the matched constant value verification scheme.

5. The method for automatic verification of distribution network protection setting values ​​based on adaptive matching according to claim 1 is characterized in that: The specific method of step 4 is: The distribution network protection switch matches the corresponding fault variable, fixed value variable, and parameter variable according to the calibration position of the calibration rule, calculates the value of the fault variable or obtains the value of the parameter variable and fixed value variable, matches the values ​​of the parameter variable, fixed value variable, fault variable and conventional variable to the variables of the calibration formula, and then calculates the calibration value through the digital formula.

6. The method for automatic verification of distribution network protection setting values ​​based on adaptive matching according to claim 1 is characterized in that: The specific method of step 5 is: Compare the setting value of the distribution network protection switch with the calibration value to see if they meet the comparison relationship. If they do, the calibration of the set value passes; otherwise, the calibration of this set value fails. The calibration results of each calibration rule are classified and counted according to the calibration type. If all the calibration rules of each calibration type pass, this set value meets this calibration type. Otherwise, an alarm is triggered for this calibration type. The objective function of the calibration result of a certain calibration type is expressed as: E=bool(M1,M2,……Mn) Among them, M is the verification result of each verification rule, and E is the verification result of this verification type; When every check rule of a certain check type is checked and satisfied, the check type is checked and satisfied; that is, the values ​​of M1~Mn are true. If only one of the values ​​of M1~Mn is false, the check type is not checked and satisfied.

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