A method for checking and optimizing the setting value coordination relationship of power grid inverse-time overcurrent protection

Abstract

The application discloses a power grid inverse-time overcurrent protection fixed value matching relationship checking and optimization method, comprising the following steps: obtaining power grid parameters of a regional power grid; searching the power grid structure from the end load of the regional power grid upwards according to the power grid parameters, and forming a device linked list of each level of protection device of the regional power grid; traversing the device linked list, extracting the protection device fixed value curve of each level of protection device, and drawing the protection fixed value curve of each level of protection device in the same coordinate system; determining the first protection action time delay of each level of protection device under the maximum mode short-circuit current and the second protection action time delay of each level of protection device under the minimum mode short-circuit current according to the intersection of the maximum mode short-circuit current and the minimum mode short-circuit current and the protection fixed value curve of each level of protection device; determining whether the up-down level protection device fixed value matching relationship of each level of protection device is reasonable; and optimizing the protection device fixed value curve of each level of protection device in the case that the up-down level protection device fixed value matching relationship is unreasonable.

Description

Technical Field

[0001] This invention relates to the field of power system operation and control technology, and more specifically, to a method for verifying and optimizing the coordination relationship of inverse time overcurrent protection settings in power grids. Background Technology

[0002] With the increasing complexity and dynamic nature of power plant power systems, coupled with weak grid structures, faults are easily induced. Furthermore, insufficient coordination among protection systems in different areas can lead to malfunctions and other hazards. Therefore, the relay protection settings of power plant power systems play a crucial role in the safe and reliable operation of the power grid.

[0003] Inverse-time overcurrent protection can effectively improve the speed of protection devices. However, due to the differences in the inverse-time characteristic curves of various protection devices, the coordination relationship between the settings of upper and lower level protection devices becomes quite complex when there are many protection levels. If the rationality of the coordination relationship between upper and lower level inverse-time overcurrent protection cannot be guaranteed, it will pose a hidden danger to the safe and stable operation of the power system. Existing technical solutions have problems such as low efficiency, poor intuitiveness, and inability to optimize unreasonable settings. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for verifying and optimizing the coordination relationship of power grid inverse-time overcurrent protection settings.

[0005] According to one aspect of the present invention, a method for verifying and optimizing the coordination relationship of inverse-time overcurrent protection settings in power grids is provided, comprising:

[0006] Obtain the grid parameters of the regional power grid, including: electrical equipment connection relationships, equipment types, electrical equipment parameters, protection device setting curves, maximum mode short-circuit current, and minimum mode short-circuit current;

[0007] Based on the grid parameters, the grid structure is searched upwards from the end load of the regional grid to form a device chain list of protection devices at all levels of the regional grid;

[0008] Traverse the device linked list, extract the protection device setpoint curves of each level of protection device, and plot the protection setpoint curves of each level of protection device in the same coordinate system;

[0009] Based on the intersection of the maximum and minimum short-circuit currents with the protection setting curves of each level of protection device, determine the first protection action delay of each level of protection device under the maximum short-circuit current and the second protection action delay of each level of protection device under the minimum short-circuit current.

[0010] Based on the delay of the first protection action and the delay of the second protection action, determine whether the coordination relationship of the upper and lower level protection device settings is reasonable.

[0011] When the coordination relationship between the upper and lower level protection devices is unreasonable, the protection device setting curves of each level protection device are optimized.

[0012] Optionally, the protection device setting curve includes regular curves and irregular curves, wherein the irregular curve is composed of line segments connected end to end.

[0013] Optionally, based on the intersection of the maximum and minimum mode short-circuit currents with the protection setting curves of each level of protection device, the first protection operation delay of each level of protection device under the maximum mode short-circuit current and the second protection operation delay of each level of protection device under the minimum mode short-circuit current are determined, including:

[0014] Based on the first set of intersections between the maximum mode short-circuit current and the protection setting curves of each level of protection device, determine the first set of protection devices that operate for the maximum mode short-circuit current;

[0015] Calculate the first protection action delay of the first action protection device set based on the first intersection point set and the maximum mode short circuit current;

[0016] Based on the second set of intersection points between the minimum short-circuit current and the protection setting curves of each level of protection device, determine the second set of protection devices that operate on the minimum short-circuit current.

[0017] Based on the second intersection point set and the minimum short-circuit current, calculate the second protection action delay of the second action protection device set.

[0018] Optionally, based on the first protection action delay and the second protection action delay, determine whether the coordination relationship of the upper and lower level protection device settings is reasonable, including:

[0019] Based on the coordination relationship of the upper and lower level protection devices of the first action protection device and the action delay of the first protection device, determine whether the coordination relationship of the upper and lower level protection devices of the first action protection device is reasonable.

[0020] Based on the coordination relationship of the upper and lower level protection devices of the second action protection device and the action delay of the second protection, determine whether the coordination relationship of the upper and lower level protection devices of the second action protection device is reasonable.

[0021] Optionally, it also includes:

[0022] When the coordination relationship of the upper and lower level protection devices of the first action protection device set is inconsistent with the sequence of the first protection action delay, it is determined that the coordination relationship of the upper and lower level protection devices of the first action protection device is unreasonable.

[0023] If the coordination relationship between the upper and lower level protection devices of the second action protection device is inconsistent with the time delay sequence of the second protection action, it is determined that the coordination relationship between the upper and lower level protection devices of the second action protection device is unreasonable.

[0024] Optionally, the protection device setpoint curves of each level of protection device are optimized, including:

[0025] Based on the pre-set objective function and pre-set constraints, the biological evolution simulation algorithm is used to iteratively calculate the inverse time overcurrent protection setting for each level of protection device setting curve, and determine the optimal protection device setting curve parameters for each level of protection device. The optimal protection device setting curve parameters include the protection start current and the time setting value.

[0026] Based on the optimal protection device setpoint curve parameters of each level of protection device, determine the optimized protection device setpoint curves for each level of protection device.

[0027] Optionally, the objective function is:

[0028]

[0029] In the formula, For the first i The first protection device k The protection starting current at each fault point For the first i The first protection device k The time setting value for each fault point.

[0030] Optionally, the constraints include:

[0031] Time difference constraint between primary protection and backup protection:

[0032]

[0033] In the formula, CTI To ensure the time difference between relays; T i,k It is the first i Each protection device is at the fault point. k The action time of the point, the first i One protection device serves as the main protection; T j,k It is the first j Each protection device is at the fault point. k The action time of the point, the first j The first protective device is the... i Backup protection for each protection device;

[0034] Time setting valueT p Constraints:

[0035]

[0036] In the formula, T pi,min , T pi,max It is not the first i The minimum and maximum time settings for each protection device;

[0037] Protect starting current I p Constraints:

[0038]

[0039] In the formula, and They are the first i Minimum and maximum starting current of each protection device;

[0040] Protection device action time T Constraints:

[0041]

[0042] In the formula, T i,min and T i,max They are the first i The minimum and maximum operating times of each protection device.

[0043] According to another aspect of the present invention, a device for verifying and optimizing the coordination relationship of inverse-time overcurrent protection settings in power grids is provided, comprising:

[0044] The acquisition module is used to acquire the power grid parameters of the regional power grid, including: electrical equipment connection relationships, equipment types, electrical equipment parameters, protection device setting curves, maximum mode short-circuit current, and minimum mode short-circuit current;

[0045] The module is used to search the grid structure upwards from the end load of the regional grid based on grid parameters, and form a device chain list of protection devices at all levels of the regional grid;

[0046] The drawing module is used to traverse the device linked list, extract the protection device setpoint curves of each level of protection device, and draw the protection setpoint curves of each level of protection device in the same coordinate system.

[0047] The first determining module is used to determine the first protection action delay of each level of protection device under the maximum mode short circuit current and the second protection action delay of each level of protection device under the minimum mode short circuit based on the intersection of the maximum mode short circuit current and the minimum mode short circuit current with the protection setting curves of each level of protection device.

[0048] The second determining module is used to determine whether the setting coordination relationship between the upper and lower level protection devices is reasonable based on the first protection action delay and the second protection action delay.

[0049] The optimization module is used to optimize the setting curves of protection devices at all levels when the setting coordination relationship between upper and lower level protection devices is unreasonable.

[0050] According to another aspect of the present invention, a computer-readable storage medium is provided, the storage medium storing a computer program for performing the methods described in any of the above aspects of the present invention.

[0051] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising: a processor; a memory for storing executable instructions of the processor; the processor being configured to read the executable instructions from the memory and execute the instructions to implement the method described in any of the preceding aspects of the present invention.

[0052] Therefore, this application proposes a method for verifying and optimizing the coordination relationship of inverse-time overcurrent protection settings in a tree-shaped power grid. This method can automatically verify the rationality of the coordination relationship between upper and lower levels of inverse-time overcurrent protection, and automatically assist in optimization for unreasonable situations. This effectively improves the rationality of inverse-time overcurrent protection settings and the efficiency of verification work, ensuring the safe and stable operation of the power system. Attached Figure Description

[0053] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures:

[0054] Figure 1 This is a flowchart illustrating the method for verifying and optimizing the coordination relationship of inverse-time overcurrent protection settings in a power grid, provided by an exemplary embodiment of the present invention.

[0055] Figure 2 This is a schematic diagram of the coordinate transformation of the inverse time-limited protection curve provided by an exemplary embodiment of the present invention;

[0056] Figure 3 This is a schematic diagram of the logic for reverse modification of a set value in an edit curve, provided by an exemplary embodiment of the present invention;

[0057] Figure 4This is a schematic diagram of the structure of a power grid inverse-time overcurrent protection setting coordination relationship verification and optimization device provided in an exemplary embodiment of the present invention;

[0058] Figure 5 This is the structure of an electronic device provided in an exemplary embodiment of the present invention. Detailed Implementation

[0059] Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0060] It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention.

[0061] Those skilled in the art will understand that the terms "first," "second," etc., in the embodiments of the present invention are only used to distinguish different steps, devices, or modules, and do not represent any specific technical meaning, nor do they indicate a necessary logical order between them.

[0062] It should also be understood that in the embodiments of the present invention, "multiple" can refer to two or more, and "at least one" can refer to one, two or more.

[0063] It should also be understood that any component, data or structure mentioned in the embodiments of the present invention can generally be understood as one or more unless explicitly defined or given contrary instructions in the context.

[0064] Furthermore, the term "and / or" in this invention is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this invention generally indicates that the preceding and following related objects have an "or" relationship.

[0065] It should also be understood that the description of the various embodiments in this invention emphasizes the differences between the various embodiments, and the similarities or similarities can be referred to each other. For the sake of brevity, they will not be described in detail.

[0066] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0067] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0068] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0069] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0070] The embodiments of this invention can be applied to electronic devices such as terminal devices, computer systems, and servers, and can operate together with a wide range of other general-purpose or special-purpose computing system environments or configurations. Well-known examples of terminal devices, computing systems, environments, and / or configurations suitable for use with electronic devices such as terminal devices, computer systems, and servers include, but are not limited to: personal computer systems, server computer systems, thin clients, thick clients, handheld or laptop devices, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputer systems, mainframe computer systems, and distributed cloud computing environments including any of the above systems, etc.

[0071] Electronic devices such as terminal devices, computer systems, and servers can be described in the general context of computer system executable instructions (such as program modules) executed by a computer system. Typically, program modules can include routines, programs, object programs, components, logic, data structures, etc., which perform specific tasks or implement specific abstract data types. Computer systems / servers can be implemented in distributed cloud computing environments, where tasks are executed by remote processing devices linked through communication networks. In distributed cloud computing environments, program modules can reside on local or remote computing system storage media, including storage devices.

[0072] Exemplary methods

[0073] Figure 1 This is a flowchart illustrating a method for verifying and optimizing the coordination relationship of inverse-time overcurrent protection settings in a power grid, provided by an exemplary embodiment of the present invention. This embodiment can be applied to electronic devices, such as... Figure 1 As shown, the method 100 for verifying and optimizing the coordination relationship of inverse-time overcurrent protection settings in power grids includes the following steps:

[0074] Step 101: Obtain the grid parameters of the regional power grid, including: electrical equipment connection relationships, equipment types, electrical equipment parameters, protection device setting curves, maximum mode short-circuit current, and minimum mode short-circuit current.

[0075] Optionally, the protection device setting curve includes regular curves and irregular curves, wherein the irregular curve is composed of line segments connected end to end.

[0076] Specifically, grid parameters can be read from regional power grid equipment. The data to be read includes electrical equipment connection relationships, equipment types and electrical equipment parameters (resistance, reactance, etc.), and protection device setting curves, mainly including starting current, action delay, characteristic curves, etc.

[0077] Step 102: Search the grid structure upwards from the end load of the regional power grid based on the grid parameters to form a device chain list of protection devices at all levels of the regional power grid.

[0078] Specifically, the system traverses all levels of loads in the power grid structure, searching from the end load to the next higher busbar, until the power supply busbar, forming a device chain list in sequence. In this device chain list, the protection devices at each level are numbered sequentially from the end load to the power supply busbar as follows: P1, P2, P3, ...

[0079] Step 103: Traverse the device linked list, extract the protection device setting curves of each level of protection device, and draw the protection setting curves of each level of protection device in the same coordinate system.

[0080] Specifically, the device linked list is traversed to extract the setpoint curves of each level of protection device and plot them on the same coordinate system. The setpoint curves of protection devices can be divided into regular curves and irregular curves.

[0081] For example, a regular curve can be expressed by the formula shown in equation (1), which describes the relationship between time and current.

[0082] (1)

[0083] In the formula, t For time, I for t The current value at time [time]. I p Tp is a time setting value to protect against starting current.

[0084] Irregular curves are composed of a set of line segments that are connected end to end; specifically, they are described as a set of ordered points, such as: ( I 0 , t 0 ） 、( I 1 ,t 1 ), ( I 2 ,t 2 ), ..., ( I n ,tn ).

[0085] The formulas for the maximum short-circuit current and the minimum short-circuit current are given in equation (2) and equation (3) respectively, and are represented as a straight line in the coordinate system.

[0086] (2)

[0087] (3)

[0088] Step 104: Based on the intersection of the maximum and minimum mode short-circuit currents with the protection setting curves of each level of protection device, determine the first protection action delay of each level of protection device under the maximum mode short-circuit current and the second protection action delay of each level of protection device under the minimum mode short-circuit current.

[0089] Optionally, based on the intersection of the maximum and minimum mode short-circuit currents with the protection setting curves of each level of protection device, the first protection operation delay of each level of protection device under the maximum mode short-circuit current and the second protection operation delay of each level of protection device under the minimum mode short-circuit current are determined, including:

[0090] Based on the first set of intersections between the maximum mode short-circuit current and the protection setting curves of each level of protection device, determine the first set of protection devices that operate for the maximum mode short-circuit current;

[0091] Calculate the first protection action delay of the first action protection device set based on the first intersection point set and the maximum mode short circuit current;

[0092] Based on the second set of intersection points between the minimum short-circuit current and the protection setting curves of each level of protection device, determine the second set of protection devices that operate on the minimum short-circuit current.

[0093] Based on the second intersection point set and the minimum short-circuit current, calculate the second protection action delay of the second action protection device set.

[0094] Specifically, each protection device at each level has a protection characteristic curve. If the short-circuit current line intersects the protection device characteristic curve, it means that under the short-circuit current condition, this protection device will operate, and the time corresponding to the intersection point is the protection device's operating delay.

[0095] The calculation method for the delay of the first or second protection action of the protection device is as follows:

[0096] For protection devices with setpoint curves that are regular curves, respectively... and Substituting the curve formula, we can obtain the protection action delay of each level of protection device under large-mode short circuit and small-mode short circuit conditions, as shown in equation (4) and equation (5).

[0097] (4)

[0098] (5)

[0099] For protection characteristic curves that are irregular, they can be considered as being composed of several line segments. A straight line can be determined based on the two endpoints of each line segment. First, based on... or Determine which line segment it falls within:

[0100] if:

[0101] (6)

[0102] The equation of the line containing the line segment is:

[0103] (7)

[0104] Will and Substituting into equation (7), we can obtain the protection action delay under large-mode short circuit and small-mode short circuit conditions, as shown in equations (8) and (9).

[0105] (8)

[0106] (9)

[0107] In the formula, t max The protection trip delay is for the maximum short-circuit current. t min To minimize the protection operation delay due to short-circuit current, i For the irregular curve of the first i One point, i >=1.

[0108] The calculations for the first and second protection operation delays of all protection devices in the device chain list under both maximum and minimum short-circuit conditions are as follows:

[0109] , , ... (10)

[0110] , , ... (11)

[0111] Step 105: Based on the first protection action delay and the second protection action delay, determine whether the setting coordination relationship between the upper and lower level protection devices is reasonable.

[0112] Optionally, based on the first protection action delay and the second protection action delay, determine whether the coordination relationship of the upper and lower level protection device settings is reasonable, including:

[0113] Based on the coordination relationship of the upper and lower level protection devices of the first action protection device and the action delay of the first protection device, determine whether the coordination relationship of the upper and lower level protection devices of the first action protection device is reasonable.

[0114] Based on the coordination relationship of the upper and lower level protection devices of the second action protection device and the action delay of the second protection, determine whether the coordination relationship of the upper and lower level protection devices of the second action protection device is reasonable.

[0115] Optionally, it also includes:

[0116] When the coordination relationship of the upper and lower level protection devices of the first action protection device set is inconsistent with the sequence of the first protection action delay, it is determined that the coordination relationship of the upper and lower level protection devices of the first action protection device is unreasonable.

[0117] If the coordination relationship between the upper and lower level protection devices of the second action protection device is inconsistent with the time delay sequence of the second protection action, it is determined that the coordination relationship between the upper and lower level protection devices of the second action protection device is unreasonable.

[0118] Specifically, the protection action delays under the maximum and minimum short-circuit conditions will be sorted from smallest to largest, and if any exist... If the upper-level protection activates first, it indicates that the corresponding upper and lower-level protection settings are not properly coordinated.

[0119] Step 106: When the setting coordination relationship between the upper and lower level protection devices is unreasonable, optimize the setting curves of the protection devices at each level.

[0120] Optionally, the protection device setpoint curves of each level of protection device are optimized, including:

[0121] Based on the pre-set objective function and pre-set constraints, the biological evolution simulation algorithm is used to iteratively calculate the inverse time overcurrent protection setting for each level of protection device setting curve, and determine the optimal protection device setting curve parameters for each level of protection device. The optimal protection device setting curve parameters include the protection start current and the time setting value.

[0122] Based on the optimal protection device setpoint curve parameters of each level of protection device, determine the optimized protection device setpoint curves for each level of protection device.

[0123] Optionally, the objective function is:

[0124] (12)

[0125] In the formula, For the first i The first protection device k The protection starting current at each fault point For the first i The first protection device k The time setting value for each fault point.

[0126] Optionally, the constraints include:

[0127] To satisfy the selectivity between the primary protection and backup protection, the time difference constraint between the primary protection and backup protection is as follows:

[0128] (13)

[0129] The above formula uses a time interval (CTI) to ensure the coordination between relays; CTI To ensure the time difference between relays; T i,k It is the first i Each protection device is at the fault point. k The action time of the point, the first i One protection device serves as the main protection; T j,k It is the first j Each protection device is at the fault point. k The action time of the point, the first j The first protective device is the... i Backup protection for each protection device;

[0130] Time tuning constraints:

[0131] (14)

[0132] In the formula, T pi,min , T pi,max It is not the first i The minimum and maximum time settings for each protection device;

[0133] Protection starting current constraint conditions:

[0134] (15)

[0135] In the formula, and They are the first i Minimum and maximum starting current of each protection device;

[0136] also, I p The setting range can also be expressed as follows:

[0137] (16)

[0138] In the formula, I p The settings should ensure that the protection device does not trip under maximum load current and can operate promptly under minimum fault current. k 1 represents the reliability coefficient. k 2 represents the sensitivity coefficient.

[0139] Constraints on the operating time of the protection device:

[0140] (17)

[0141] In the formula, T i,min and T i,max They are the first i The minimum and maximum operating times of each protection device.

[0142] Specifically, for protection systems with unreasonable coordination between upper and lower level protection settings, this is reflected in the time-current curve coordinate as an intersection point between the two protection setting characteristic curves at the maximum mode short-circuit current and the minimum mode short-circuit current.

[0143] The setting calculation of inverse-time overcurrent protection is transformed into an optimization model. The coordination problem between the main protection and backup protection is converted into constraints. The sum of the operating times of the main protection and backup protection is used as the objective function for optimization, while the time difference between upper and lower level protections, starting current, and operating time are used as constraints. The inverse-time characteristic adopts a general form, which is determined by adjusting the time setting values ​​of each level of protection device. T p and protection starting current I p Simultaneously optimize.

[0144] To quickly and accurately solve the system of equations relating the objective function and constraints, this invention proposes a biological evolution simulation algorithm. The algorithm consists of three stages: a symbiotic stage, a competitive stage, and a parasitic stage. In each stage, each organism has the possibility of randomly utilizing other organisms. In the first stage, organisms coexist in a mutually beneficial symbiotic relationship; in the second stage, one organism gains an advantageous position while the other remains neutral; in the third stage, the first organism is in a dominant position while the other is in a disadvantageous position.

[0145] Assumption X i It is the first in the biosphere i Species Y j It is in the biosphere and X i The first symbiotic relationship j Biological organisms. In the first stage, both types of organisms are in their initial state. X i and Y j .

[0146] (18)

[0147] (19)

[0148] (20)

[0149] In the formula, rand(0,1) is a random number between 0 and 1; B F1 and B F2 It is a favorable factor, which can be randomly selected as 1 or 2; B They were the organisms in the most advantageous position in the initial ecosystem; X i，new and Y j，new They are species X i and species Y j The updated state; M is an intermediate variable, with the value being the species. X i and species Y j The average value.

[0150] In the second phase, two organisms X are still randomly selected. i and Y j X i To gain an advantage in a symbiotic relationship, Y jIt neither gains an advantage nor is it at a disadvantage; it remains in a neutral position. X i The changing trends are as follows:

[0151] (twenty one)

[0152] In the formula, rand(-1,1) is a random number between -1 and 1, which is assigned only when X... i，new Compared to X i When it is more advantageous, X i It will then be updated to X i，new Y j Still in the initial state Y j .

[0153] In the third stage, it is assumed that two organisms X are still randomly selected. i and Y j X i and Y j It is a parasitic relationship, X i To be in a dominant position, Y j They are in a disadvantageous position. Assume that in X... i and Y j During the update process, there exists a factor P such that X i，new Compared to X i With better adaptability, X i Biology has the advantage; let Y j，new Compared to Y j With better adaptability, Y j At a disadvantage. Ultimately satisfying X. i Dominant, while Y j Extinction or X i Replacement.

[0154] Favorable factors B F1 and B F2 Improved to AB F1 and AB F2 ,as follows:

[0155] (twenty two)

[0156] After the improvements, in the first stage, the two types of organisms X i and Y j The following updates are made:

[0157] (twenty three)

[0158] (twenty four)

[0159] (25)

[0160] This biological evolution simulation algorithm is used to calculate the inverse time overcurrent protection setting, with variables... T p and I p The initial values ​​are all random values ​​within the upper and lower limits, and the number of biological species N can be chosen as 20. Based on this algorithm, a more optimal [calculation / calculation] can be obtained. T p and I p This also reduces the time of the main protection and backup protection, and improves the coordination between upper and lower level protection.

[0161] According to the adjusted set value T p and I p Generate a new value sheet.

[0162] Furthermore, this application also allows for visual manual optimization of the protection device setting curve. For the protection setting characteristic curve shown in equation (26), the original protection device setting curve... f The base point of 1 is (a, b). Shifting the protection setting characteristic curve to the position (a+a0, b+b0), the protection device setting curve... f This becomes equation (27).

[0163] (26)

[0164] (27)

[0165] The protection setpoint characteristic curve before and after translation is as follows Figure 2 As shown.

[0166] The logic for reversing the setting value by editing the protection device's setting curve is as follows: Figure 3 As shown, by parsing and reading the changes in the coordinates of curve elements, the protection configuration parameters are modified according to the mapping rules, and the new curve labels and configurations are updated simultaneously. The reverse modification interaction steps for other protection characteristics are consistent with this example. Each protection device setting curve is described by several parameters; editing a curve is essentially modifying these parameters. These curve parameters correspond to the corresponding protection device parameters, and the specific correspondence rules depend on the specific protection device and the curve description method.

[0167] This application classifies the inverse-time overcurrent protection setting characteristic curve into two forms: regular curves and irregular curves. Starting from the load at the end of the tree-shaped power grid and extending along the line to the power supply path, the characteristic curves of the protection devices along the path are plotted on the same coordinate plane. Within the ranges of large-mode and small-mode short-circuit currents, the intersection points of the short-circuit current line and each protection setting characteristic curve are calculated. Combining the relative positions of each protection device and the intersection points of the protection setting characteristic curves, the rationality of the coordination relationship between upper and lower level protection settings is determined. Addressing the problems of unreasonable coordination relationships such as time overlap, insufficient time interval, and excessively large time interval between upper and lower level protection settings in inverse-time overcurrent protection, a tree-shaped power grid inverse-time overcurrent protection setting optimization method is proposed that satisfies the requirements of upper and lower level protection setting coordination while ensuring the speed and accuracy of protection device operation. This method aims to minimize the weighted sum of the operating times of all protection devices, with the time difference between upper and lower level protections, starting current, and operating time as constraints. The solution yields more reasonable settings for each level of protection.

[0168] This invention is mainly applied to the verification of relay protection settings in tree-shaped power grids, such as power plant auxiliary power systems, industrial enterprise power systems, and traditional distribution networks. It is particularly useful for situations where the coordination relationship of inverse time overcurrent protection is complex. It can quickly verify the rationality of the coordination between upper and lower levels of protection settings. At the same time, it supports the modification of system protection settings through graphic element editing, or the automatic optimization and adjustment of protection settings. It is not only convenient and intuitive to operate, but also greatly improves the rationality of inverse time overcurrent protection settings and the efficiency of verification work.

[0169] Therefore, this application proposes a method for verifying and optimizing the coordination relationship of inverse-time overcurrent protection settings in a tree-shaped power grid. This method can automatically verify the rationality of the coordination relationship between upper and lower levels of inverse-time overcurrent protection, and automatically assist in optimization for unreasonable situations. This effectively improves the rationality of inverse-time overcurrent protection settings and the efficiency of verification work, ensuring the safe and stable operation of the power system.

[0170] Exemplary device

[0171] Figure 4 This is a schematic diagram of the structure of a power grid inverse-time overcurrent protection setting coordination relationship verification and optimization device provided in an exemplary embodiment of the present invention. Figure 4 As shown, the device 400 includes:

[0172] The acquisition module 410 is used to acquire the power grid parameters of the regional power grid, including: electrical equipment connection relationships, equipment types, electrical equipment parameters, protection device setting curves, maximum mode short-circuit current and minimum mode short-circuit current;

[0173] The forming module 420 is used to search the grid structure upward from the end load of the regional grid according to the grid parameters, and form a device chain list of protection devices at all levels of the regional grid;

[0174] The drawing module 430 is used to traverse the equipment linked list, extract the protection device setpoint curves of each level of protection device, and draw the protection setpoint curves of each level of protection device in the same coordinate system.

[0175] The first determining module 440 is used to determine the first protection action delay of each level of protection device under the maximum mode short circuit current and the second protection action delay of each level of protection device under the minimum mode short circuit based on the intersection of the maximum mode short circuit current and the minimum mode short circuit current with the protection setting curves of each level of protection device.

[0176] The second determining module 450 is used to determine whether the setting coordination relationship between the upper and lower level protection devices is reasonable based on the first protection action delay and the second protection action delay.

[0177] The optimization module 460 is used to optimize the setting curves of protection devices at all levels when the setting coordination relationship between the upper and lower level protection devices is unreasonable.

[0178] Optionally, the protection device setting curve includes regular curves and irregular curves, wherein the irregular curve is composed of line segments connected end to end.

[0179] Optionally, the first determining module 440 includes:

[0180] The first determining submodule is used to determine the first set of operating protection devices for the maximum mode short circuit current based on the first set of intersection points between the maximum mode short circuit current and the protection setting curves of each level of protection devices.

[0181] The first calculation submodule is used to calculate the first protection action delay of the first action protection device set based on the first intersection point set and the maximum mode short circuit current.

[0182] The second determining submodule is used to determine the second set of operating protection devices for the minimum mode short circuit current based on the second set of intersection points between the minimum mode short circuit current and the protection setting curves of each level of protection devices;

[0183] The second calculation submodule is used to calculate the second protection action delay of the second action protection device set based on the second intersection point set and the minimum short-circuit current.

[0184] Optionally, the second determining module 450 includes:

[0185] The third determining submodule is used to determine whether the setting coordination relationship between the upper and lower level protection devices of the first action protection device is reasonable based on the setting coordination relationship between the upper and lower level protection devices of each protection device in the first action protection device set and the first protection action delay.

[0186] The fourth determination submodule is used to determine whether the setting coordination relationship between the upper and lower level protection devices of the second action protection device is reasonable based on the setting coordination relationship between the upper and lower level protection devices of each protection device in the second action protection device set and the second protection action delay.

[0187] Optionally, the device 400 further includes:

[0188] The third determining module is used to determine that the setting coordination relationship between the upper and lower level protection devices of the first action protection device is unreasonable when the coordination relationship between the upper and lower level protection devices of each protection device in the first action protection device set is inconsistent with the time delay sequence of the first protection action.

[0189] The fourth determination module is used to determine that the setting coordination relationship between the upper and lower level protection devices of the second action protection device is unreasonable when the setting coordination relationship between the upper and lower level protection devices of the second action protection device is inconsistent with the action delay sequence of the second protection device.

[0190] Optionally, the optimization module 460 includes:

[0191] The fifth determination submodule is used to perform inverse time overcurrent protection setting calculations on the protection device setting curves of each level of protection device according to the pre-set objective function and pre-set constraints, using a biological evolution simulation algorithm, to determine the optimal protection device setting curve parameters for each level of protection device. The optimal protection device setting curve parameters include the protection start current and the time setting value.

[0192] The sixth determination submodule is used to determine the optimized protection device setting curves for each level of protection device based on the optimal protection device setting curve parameters for each level of protection device.

[0193] Optionally, the objective function is:

[0194]

[0195] In the formula, For the first i The first protection device k The protection starting current at each fault point For the first i The first protection device k The time setting value for each fault point.

[0196] Optionally, the constraints include:

[0197] Time difference constraint between primary protection and backup protection:

[0198]

[0199] In the formula, CTI To ensure the time difference between relays; T i,k It is the first i Each protection device is at the fault point. k The action time of the point, the first i One protection device serves as the main protection; T j,k It is the first j Each protection device is at the fault point. k The action time of the point, the first j The first protective device is the... i Backup protection for each protection device;

[0200] Time setting value T p Constraints:

[0201]

[0202] In the formula, T pi,min , T pi,max It is not the first i The minimum and maximum time settings for each protection device;

[0203] Protect starting current I p Constraints:

[0204]

[0205] In the formula, and They are the first i Minimum and maximum starting current of each protection device;

[0206] Protection device action time T Constraints:

[0207]

[0208] In the formula, T i,min and T i,max They are the first i The minimum and maximum operating times of each protection device.

[0209] Exemplary electronic devices

[0210] Figure 5 This is the structure of an electronic device provided in an exemplary embodiment of the present invention. For example... Figure 5As shown, the electronic device 50 includes one or more processors 51 and memory 52.

[0211] The processor 51 may be a central processing unit (CPU) or other form of processing unit with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions.

[0212] The memory 52 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 51 may execute the program instructions to implement the methods of the software programs of the various embodiments of the present invention described above, and / or other desired functions. In one example, the electronic device may also include an input device 53 and an output device 54, these components being interconnected via a bus system and / or other forms of connection mechanisms (not shown).

[0213] In addition, the input device 53 may also include, for example, a keyboard, a mouse, etc.

[0214] The output device 54 can output various information to the outside. The output device 54 may include, for example, a display, a speaker, a printer, and a communication network and its connected remote output devices, etc.

[0215] Of course, for the sake of simplicity, Figure 5 Only some of the components of this electronic device relevant to the present invention are shown, omitting components such as buses, input / output interfaces, etc. In addition, the electronic device may include any other suitable components depending on the specific application.

[0216] Exemplary computer program products and computer-readable storage media

[0217] In addition to the methods and apparatus described above, embodiments of the present invention may also be computer program products, which include computer program instructions that, when executed by a processor, cause the processor to perform the steps in the methods according to various embodiments of the present invention described in the "Exemplary Methods" section above.

[0218] The computer program product can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of the present invention. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0219] Furthermore, embodiments of the present invention may also be computer-readable storage media storing computer program instructions thereon, which, when executed by a processor, cause the processor to perform the steps of the methods according to various embodiments of the present invention described in the "Exemplary Methods" section above.

[0220] The computer-readable storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, system, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0221] The basic principles of the present invention have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in the present invention are merely examples and not limitations, and should not be considered as essential features of each embodiment of the present invention. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the present invention to the necessity of employing the aforementioned specific details.

[0222] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For system embodiments, since they largely correspond to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0223] The block diagrams of devices, systems, devices, and systems involved in this invention are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, systems, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0224] The methods and systems of the present invention may be implemented in many ways. For example, they may be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above-described order of steps for the methods is for illustrative purposes only, and the steps of the methods of the present invention are not limited to the order specifically described above unless otherwise specifically stated. Furthermore, in some embodiments, the present invention may also be implemented as a program recorded on a recording medium, the program comprising machine-readable instructions for implementing the methods according to the present invention. Thus, the present invention also covers recording media storing programs for performing the methods according to the present invention.

[0225] It should also be noted that in the systems, apparatus, and methods of the present invention, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered equivalents of the present invention. The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the invention. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the invention. Therefore, the invention is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.

[0226] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the invention to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.

Claims

1. A method for checking and optimizing the setting coordination relationship of power grid inverse time overcurrent protection, characterized in that, The method comprises the following steps: acquiring power grid parameters of a regional power grid, wherein the power grid parameters comprise: electrical equipment connection relationship, equipment type, electrical equipment parameters, protection device setting curve, maximum mode short-circuit current, and minimum mode short-circuit current; searching for power grid structure from the end load of the regional power grid upwards according to the power grid parameters, and forming a device chain table of protection devices at each level of the regional power grid; traversing the device chain table, extracting protection device setting curves of protection devices at each level, and drawing the protection setting curves of protection devices at each level in the same coordinate system; determining first protection action time delays of protection devices at each level under the maximum mode short-circuit current and second protection action time delays of protection devices at each level under the minimum mode short-circuit current according to the intersection points of the maximum mode short-circuit current and the minimum mode short-circuit current and the protection setting curves of protection devices at each level; determining whether the up-down protection device setting cooperation relationship of protection devices at each level is reasonable according to the first protection action time delays and the second protection action time delays; optimizing the protection device setting curves of protection devices at each level in the case that the up-down protection device setting cooperation relationship of protection devices at each level is unreasonable; the protection device setting curve comprises a regular curve and an irregular curve, wherein the irregular curve is composed of line segments connected at the head and tail; optimizing the protection device setting curves of protection devices at each level comprises: determining optimal protection device setting curve parameters of protection devices at each level by respectively performing inverse time overcurrent protection setting calculation on the protection device setting curves of protection devices at each level according to a pre-set target function and a pre-set constraint condition, wherein the optimal protection device setting curve parameters comprise protection starting current and time setting value; determining optimized protection device setting curves of protection devices at each level according to the optimal protection device setting curve parameters of protection devices at each level; the target function is: In the formula, is the protection starting current of the kth fault point of the ith protection device, is the time setting value of the kth fault point of the ith protection device; the constraint condition comprises: time difference constraint condition between main protection and backup protection: T j,k -T i,k ≥CTI In the formula, CTI is the time level difference for ensuring the mutual cooperation between relays; T i,k is the action time of the i-th protection device at the fault point k, and the i-th protection device is the main protection; j,k is the action time of the j-th protection device at the fault point k, and the j-th protection device is the backup protection of the i-th protection device; Time setting value T p Constraint: T pi,min ≤T p ≤T pi,max In the formula, T pi,min , T pi,max is the minimum time setting value and the maximum time setting value of the i-th protection device, respectively. Protect start current I p Constraints: I pi,min ≤I p ≤I pi,max where I pi,min and I pi,max are the minimum starting current and the maximum starting current of the i-th protection device, respectively; protection device action time T constraint condition: T i,min ≤T≤T i,max In the formula, T i,min and T i,max are the minimum and maximum action times of the i-th protection device, respectively.

2. The method of claim 1, wherein, determining first protection action time delays of protection devices at each level under the maximum mode short-circuit current and second protection action time delays of protection devices at each level under the minimum mode short-circuit current according to the intersection points of the maximum mode short-circuit current and the minimum mode short-circuit current and the protection setting curves of protection devices at each level comprises: determining a first action protection device set of the maximum mode short-circuit current according to a first intersection point set of the maximum mode short-circuit current and the protection setting curves of protection devices at each level; calculating the first protection action time delays of the first action protection device set according to the first intersection point set and the maximum mode short-circuit current; determining a second action protection device set of the minimum mode short-circuit current according to a second intersection point set of the minimum mode short-circuit current and the protection setting curves of protection devices at each level; calculating the second protection action time delays of the second action protection device set according to the second intersection point set and the minimum mode short-circuit current.

3. The method of claim 2, wherein, According to the first protection action time delay and the second protection action time delay, it is determined whether the upper and lower protection device setting value matching relationship of each level of protection device is reasonable, comprising: According to the upper and lower protection device setting value matching relationship of each protection device in the first action protection device and the first protection action time delay, it is determined whether the upper and lower protection device setting value matching relationship of the first action protection device is reasonable; According to the upper and lower protection device setting value matching relationship of each protection device in the second action protection device and the second protection action time delay, it is determined whether the upper and lower protection device setting value matching relationship of the second action protection device is reasonable.

4. The method of claim 3, wherein, Also including: In the case that the upper and lower protection device setting value matching relationship of each protection device in the first action protection device and the first protection action time delay sequence are inconsistent, it is determined that the upper and lower protection device setting value matching relationship of the first action protection device is unreasonable; In the case that the upper and lower protection device setting value matching relationship of each protection device in the second action protection device and the second protection action time delay sequence are inconsistent, it is determined that the upper and lower protection device setting value matching relationship of the second action protection device is unreasonable.

5. A device for checking and optimizing the setting coordination relationship of power grid inverse time overcurrent protection, used for implementing the method of any one of claims 1-4, characterized in that, Including: An acquisition module is configured to acquire power grid parameters of a regional power grid, wherein the power grid parameters include: electrical equipment connection relationship, equipment type, electrical equipment parameters, protection device setting value curve, maximum mode short-circuit current, and minimum mode short-circuit current; A forming module is configured to search the power grid structure from the end load of the regional power grid upwards according to the power grid parameters, and form a device chain table of each level of protection device of the regional power grid; A drawing module is configured to traverse the device chain table, extract the protection device setting value curve of each level of protection device, and draw the protection setting value curve of each level of protection device in the same coordinate system; A first determination module is configured to determine the first protection action time delay of each level of protection device under the maximum mode short-circuit current and the second protection action time delay of each level of protection device under the minimum mode short-circuit current according to the intersection of the maximum mode short-circuit current and the minimum mode short-circuit current and the protection setting value curve of each level of protection device; A second determination module is configured to determine whether the upper and lower protection device setting value matching relationship of each level of protection device is reasonable according to the first protection action time delay and the second protection action time delay; An optimization module is configured to optimize the protection device setting value curve of each level of protection device in the case that the upper and lower protection device setting value matching relationship of each level of protection device is unreasonable.

6. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, and the computer program is used to execute the method in any one of claims 1-4.

7. An electronic device, comprising: The electronic device includes: A processor; A memory for storing executable instructions of the processor; The processor is configured to read the executable instructions from the memory and execute the instructions to implement the method in any one of claims 1-4.

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