Distribution line protection adaptive configuration method and device matched with operation mode and power flow change, medium and product

Abstract

The invention discloses a distribution line protection self-adaptive configuration method and device matched with operation modes and power flow changes, a medium and a product, and relates to the technical field of distribution line protection.The method comprises the steps that firstly, the operation mode changes of a distribution line are judged in real time, and through distribution line three-level switch protection setting calculation and distributed power supply checking, the distribution line three-level switch protection setting calculation is calculated; and obtaining a distribution line switch protection constant value in the current operation state, and remotely downloading the distribution line switch protection constant value to the power distribution terminal, thereby realizing accurate and rapid fault removal of distribution line protection in various operation modes. Compared with the prior art, the distribution line topology model adopted by the invention comprises three stages of switches including the transformer substation outgoing line switch, the section switch and the branch line switch, a branch line switch protection setting calculation method is provided, and the applicability is high.

Description

Technical Field

[0001] This application relates to the field of power distribution line protection technology, and in particular to a method, device, medium and product for adaptive configuration of power distribution line protection that matches operating mode and power flow changes. Background Technology

[0002] The power distribution network is the link that directly supplies power to users, and its safe and reliable operation is directly related to the power quality of users. Power distribution lines are characterized by their large number, complex structure, and harsh and challenging operating environments, resulting in a high probability and frequency of faults. Therefore, precise and rapid protection configurations are crucial for ensuring the safe and reliable power supply of the power distribution network.

[0003] Distribution networks are characterized by frequent planned maintenance, frequent defects and faults, and fluctuating output from distributed power sources due to weather changes. This leads to frequent changes in distribution network operation modes and power flow. However, most existing distribution network protection configurations employ three-stage overcurrent protection with fixed protection settings, failing to adapt to real-time changes in network operation modes and power flow. Consequently, protection maloperation and failure to operate frequently occur when distribution network operation modes and power flow change. Therefore, there is an urgent need for an adaptive protection configuration method for distribution lines that matches changes in operation modes and power flow, enabling precise fault clearing and rapid isolation.

[0004] Existing technologies have proposed a data-driven adaptive setting method for distribution network protection settings. However, this method only considers the protection coordination of the main line switches of the distribution line under mode adjustment, and does not set the protection of branch line switches, making it difficult to apply to the current multi-segment and multi-connection topology of distribution lines. Summary of the Invention

[0005] The purpose of this application is to provide a method, device, medium, and product for adaptive configuration of power distribution line protection that matches the changes in operating mode and power flow. This method can take into account the requirements of flexible changes in operating mode for protection configuration and can be applied to the current multi-segment and multi-connection topology of power distribution lines.

[0006] To achieve the above objectives, this application provides the following solution: Firstly, this application provides an adaptive configuration method for distribution line protection that matches operating modes and power flow changes, including: Real-time acquisition of power distribution line interconnection switch S L Changes in position; If the power distribution line interconnection switch S L If the position changes from closed to open, the protection settings for normal operating mode are retrieved. If the power distribution line interconnection switch S LTo change from a detached to a closed position, iterate through the positions of all substation switches on the corresponding distribution line and assign the number of the substation switch in the detached position to the variable n, thus obtaining the detached switch S. n The substation switches include: outgoing line switches and sectionalizing switches; The setting position of the front-end switch is calculated according to the formula x=ni; where x represents the setting position of the front-end switch, and i represents the number of iterations. After each iteration, the i+1 operation is performed. When the current section switch setting is equal to 0, the overcurrent protection setting of the outgoing line switch overcurrent protection stage I is calculated by using the method of avoiding the maximum short-circuit current when there is a fault at the end of the line; the overcurrent protection setting of the outgoing line switch overcurrent protection stage II is calculated by using the method of ensuring that the minimum short-circuit current at the end of the line section can be cut off; the overcurrent protection setting of the outgoing line switch overcurrent protection stage III is calculated by using the method of avoiding the maximum load current, thus obtaining the set of outgoing line switch overcurrent protection settings; When the setting value of the upstream sectionalizing switch is greater than 0, the overcurrent protection setting value of stage I of the upstream sectionalizing switch is calculated by using the method of avoiding the maximum short-circuit current during a fault at the end of the line; the formula is then used. Calculate the overcurrent protection settings for stage II of the upstream sectionalizing switch to obtain the set of overcurrent protection settings for the upstream sectionalizing switch; among which, K rel For reliability coefficient, The overcurrent protection setting for stage II of the sectionalizing switch overcurrent protection is set as follows. I Sx_load_max This represents the maximum load current. After obtaining the overcurrent protection setting set of the outgoing line switch and the overcurrent protection setting set of the upstream section switch; using the method of avoiding the maximum short-circuit current when the distribution transformer at the end of the branch line fails, calculate the overcurrent protection setting of the upstream branch line switch I section; using the method of avoiding the maximum load current setting of the branch line, calculate the overcurrent protection setting of the upstream branch line switch II section, and obtain the overcurrent protection setting set of the upstream branch line switch. When the setting value of the current section switch is less than 0, the protection setting value of the subsequent section switch is set to obtain the protection setting value of the subsequent section switch.

[0007] Optionally, when the setting value of the current section switch is less than 0, the protection setting value of the subsequent section switch is set to obtain the protection setting value of the subsequent section switch, specifically including: The overcurrent protection setting value of section I of the downstream sectionalizing switch is calculated by using the method of avoiding the maximum short-circuit current when there is a fault at the end of the line. The overcurrent protection setting value of the second stage of the overcurrent protection of the downstream sectionalizing switch is calculated by using the method of avoiding the maximum load current flowing through the sectionalizing switch. The overcurrent protection setting value of stage I of the branch line switch is calculated by using the method of avoiding the maximum short-circuit current when the distribution transformer at the end of the branch line fails. By using the method of avoiding the maximum load current of the branch line, the overcurrent protection setting value of the second stage of the overcurrent protection of the downstream branch line switch is calculated.

[0008] Alternatively, by utilizing the method of avoiding the maximum short-circuit current during a fault at the end of the line, the calculation formula for the overcurrent protection setting of section I of the downstream sectionalizing switch is as follows: ; In the formula, K rel The reliability coefficient; I D(y-1)_fmax D y-1 The fault current when a three-phase short circuit occurs at the node; where D y-1 The node is the node of the next-level segment switch of the current setting calculation switch Sy in the subsequent section; The formula for calculating the overcurrent protection setting of the second stage of the sectionalizing switch, by utilizing the method of avoiding the maximum load current flowing through the sectionalizing switch, is as follows: ; in, I Sx_load_max Indicates the maximum load current; The formula for calculating the overcurrent protection setting of stage I of the downstream branch line switch, using the method of avoiding the maximum short-circuit current during a fault in the distribution transformer at the end of the branch line, is as follows: ; In the formula, I Fy_T_fmax This is the fault current when a three-phase short circuit occurs at the distribution transformer at the end of branch line Fy; branch line Fy is D. y Node to D y+1 Branch lines between nodes that supply power to users; D y The node is the current setting calculation switch S in the subsequent stage. y The node, D y+1 The node is the current setting calculation switch S in the subsequent stage. y The node where the next level segment switch is located; Using the method of avoiding the maximum load current of the branch line, the calculation formula for the overcurrent protection setting of the second stage of the branch line overcurrent protection is as follows: ; in, I Fy_load_max This represents the maximum load current flowing through the branch line Fy.

[0009] Alternatively, by utilizing the method of avoiding the maximum short-circuit current during a fault in the distribution transformer at the end of the branch line, the calculation formula for the overcurrent protection setting of stage I of the upstream branch line switch is as follows: ; In the formula, K rel The reliability coefficient; I Fx_T_fmax This refers to the fault current when a three-phase short circuit occurs in the distribution transformer of the end user. Using the method of avoiding the maximum load current setting of the branch line, the calculation formula for the overcurrent protection setting value of the second stage of the upstream branch line switch is as follows: ; In the formula, I Fx_load_max This is the maximum load current for the users connected to this branch line.

[0010] Alternatively, by utilizing the method of avoiding the maximum short-circuit current during a fault at the end of the line, the calculation formula for the overcurrent protection setting of stage I of the line switch is as follows: ; in, K rel The reliability coefficient; I D1_fmax This refers to the fault current when a three-phase short circuit occurs at the first node of a power distribution line segment. Using the method of ensuring the minimum short-circuit current at the end of the line section can be cut off, the calculation formula for the overcurrent protection setting of the line switch overcurrent protection stage II is as follows: ; in, K sen Sensitivity coefficient; I D1_fmin This refers to the fault current when a two-phase short circuit occurs at the first node of a power distribution line segment. Using the method of avoiding the maximum load current, the calculation formula for the overcurrent protection setting of stage III of the line switch overcurrent protection is as follows: ; Among them, the maximum load current I S0_load_max The calculation formula is: ; In the formula, I 0_t The load current flowing through the outgoing switch S0, I n_t This represents the load current flowing through the divider switch Sn.

[0011] Alternatively, by utilizing the method of avoiding the maximum short-circuit current during a fault at the end of the line, the calculation formula for the overcurrent protection setting of stage I of the upstream sectionalizing switch is as follows: ; In the formula, K rel For reliability coefficient, I D(x+1)_fmax This is the fault current when a three-phase short circuit occurs at the end node of the line, and the action time is taken as 0s.

[0012] Optionally, when the setting value of the current section switch is less than 0, the protection setting value of the subsequent section switch is set. After obtaining the protection setting value of the subsequent section switch, the following steps are also included: If the power distribution line has no distributed power source, but there is a distributed power source after the mode is adjusted, then the protection of the outgoing switch and each section switch of the power distribution line shall be locked with the direction blocking element. If the power distribution line has distributed power sources, but there are no distributed power sources after the mode is adjusted, then the protection of the outgoing switches and each section switches of the power distribution line shall be locked out of the directional blocking element.

[0013] In a second aspect, this application provides a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the adaptive configuration method for power distribution line protection that matches the operating mode and power flow changes as described above.

[0014] Thirdly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the adaptive configuration method for power distribution line protection that matches the operating mode and power flow changes as described above.

[0015] Fourthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the adaptive configuration method for power distribution line protection that matches the operating mode and power flow changes as described above.

[0016] According to the specific embodiments provided in this application, the following technical effects are disclosed: This application provides a method, device, medium, and product for adaptive configuration of power distribution line protection to match operating modes and power flow changes. The method includes: real-time acquisition of power distribution line tie switch S. L The position changes; if the power distribution line interconnection switch S L If the switch changes from closed to open, the normal operating mode protection settings are retrieved; if the power distribution line interconnection switch S... LTo change from a detached to a closed position, iterate through the positions of all substation switches on the corresponding distribution line and assign the number of the substation switch in the detached position to the variable n, thus obtaining the detached switch S. n The substation switches include: outgoing line switches and sectionalizing switches; the setting position of the front-end switch is calculated according to the formula x=ni; where x represents the setting position of the front-end switch, and i represents the number of iterations, with i+1 operation performed after each iteration; when the setting position of the front-end switch is equal to 0, the overcurrent protection setting value of the outgoing line switch overcurrent protection stage I is calculated using the method of avoiding the maximum short-circuit current when there is a fault at the end of the line; the overcurrent protection setting value of the outgoing line switch overcurrent protection stage II is calculated using the method of ensuring that the minimum short-circuit current at the end of the line can be cleared; the overcurrent protection setting value of the outgoing line switch overcurrent protection stage III is calculated using the method of avoiding the maximum load current, thus obtaining the set of outgoing line switch overcurrent protection settings; when the setting position of the front-end switch is greater than 0, the overcurrent protection setting value of the front-end sectionalizing switch overcurrent protection stage I is calculated using the method of avoiding the maximum short-circuit current when there is a fault at the end of the line; using the formula Calculate the overcurrent protection settings for stage II of the upstream sectionalizing switch to obtain the set of overcurrent protection settings for the upstream sectionalizing switch; among which, K rel For reliability coefficient, The overcurrent protection setting for stage II of the sectionalizing switch overcurrent protection is set as follows. I Sx_load_max The maximum load current is used as the reference value. After obtaining the overcurrent protection setting set of the outgoing line switch and the overcurrent protection setting set of the upstream section switch, the overcurrent protection setting of the upstream branch line switch I stage is calculated by using the method of avoiding the maximum short-circuit current when the distribution transformer at the end of the branch line fails. The overcurrent protection setting of the upstream branch line switch II stage is calculated by using the method of avoiding the maximum load current setting of the branch line, thus obtaining the overcurrent protection setting set of the upstream branch line switch. When the setting value of the upstream section switch is less than 0, the protection setting value of the downstream switch is set to obtain the protection setting value of the downstream switch. This application can judge the changes in the operating mode of the distribution line in real time, and obtain the protection setting value of the distribution line switch under the current operating state through the three-level switch protection setting calculation of the distribution line, so as to realize the accurate and rapid fault isolation of the distribution line protection under various operating modes. Compared with existing technologies, the power distribution line topology model adopted in this application includes three levels of switches: substation outgoing switches, sectionalizing switches, and branch line switches. It also provides a calculation method for the protection setting of branch line switches, which has strong applicability. Therefore, this application can take into account the requirements of flexible changes in operation mode for protection configuration and can be applied to the current multi-segment and multi-connection topology of power distribution lines. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is an application environment diagram of an adaptive configuration method for distribution line protection that matches operating mode and power flow changes, according to an embodiment of this application.

[0019] Figure 2 This is a flowchart illustrating an adaptive configuration method for power distribution line protection that matches operating modes and power flow changes, provided as an embodiment of this application.

[0020] Figure 3 This is a topology diagram of a multi-segment, multi-connection power distribution line provided in an embodiment of this application.

[0021] Figure 4 This is a modified multi-segment, multi-connection power distribution line topology diagram provided for one embodiment of this application.

[0022] Figure 5 This is a block diagram of an adaptive setting module for the protection setting of a power distribution line switch provided in an embodiment of this application.

[0023] Figure 6 A block diagram of a front-end switch protection setting module provided in an embodiment of this application.

[0024] Figure 7 A block diagram of a downstream switch protection setting module provided in an embodiment of this application.

[0025] Figure 8 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] This application aims to provide an adaptive configuration method for distribution line protection that matches changes in distribution network operation mode and power flow. First, it determines changes in distribution line operation mode in real time. Then, through calculation of the three-level switch protection settings and distributed power source verification, it obtains the current operating state's switch protection settings and remotely downloads them to the distribution terminal, enabling accurate and rapid fault isolation by distribution line protection under various operating modes.

[0028] Compared with existing technologies, the power distribution line topology model adopted in this application includes three levels of switches: substation outgoing switches, sectionalizing switches, and branch line switches. It provides a calculation method for the protection setting of branch line switches, which has strong applicability. In addition, this application provides an adaptive setting calculation module for protection settings under changes in operating mode and a distributed power source verification module, which can simultaneously solve the problem of mismatch between protection settings under distributed power source participation and changes in operating mode.

[0029] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] The adaptive configuration method for distribution line protection that matches operating modes and power flow changes provided in this application embodiment can be applied to, for example... Figure 1 In the application environment shown, terminal 102 communicates with server 104 via a network. A data storage system can store the data that server 104 needs to process. The data storage system can be set up independently, integrated into server 104, or placed in the cloud or on other servers. Terminal 102 can be, but is not limited to, various desktop computers, laptops, smartphones, tablets, IoT devices, and portable wearable devices. IoT devices can include smart speakers, smart TVs, smart air conditioners, smart in-vehicle devices, etc. Portable wearable devices can include smartwatches, smart bracelets, head-mounted devices, etc. Server 104 can be implemented using a standalone server, a server cluster consisting of multiple servers, or a cloud server.

[0031] In one exemplary embodiment, such as Figure 2 As shown, an adaptive configuration method for distribution line protection that matches operating modes and power flow changes is provided. This method is executed by computer equipment, specifically by a terminal or server alone, or by both a terminal and a server. In this embodiment, the method is applied to... Figure 1 Taking server 104 as an example, the following steps are included. The topology diagram of the multi-segment, multi-connection power distribution line is shown below. Figure 3 As shown. Where S0 is the substation outgoing switch, S1 and S2 are sectionalizing switches, S... LF1, F2, and F0 are tie switches; D1, D2, and D3 are branch line switches. L These are the distribution line segment nodes; Bus1 and Bus2 are the 10kV busbars within the substation.

[0032] When the mode is adjusted due to planned maintenance or self-healing of the power distribution line, the switch position of the power distribution line will change, such as... Figure 4 This demonstrates one typical case.

[0033] Power distribution lines typically employ a three-level protection configuration, with the switches providing the first, second, and third levels of protection being: substation outgoing line switches, sectionalizing switches, and user branch line switches, respectively. By coordinating the protection settings and operating times of these three types of switches, the speed, sensitivity, selectivity, and reliability of the power distribution line protection are achieved.

[0034] Among them, substation outgoing line switches mostly adopt three-stage overcurrent protection, namely instantaneous overcurrent protection, time-limited overcurrent protection, and time-limited overcurrent protection; in order to meet the requirements of protection coordination between upper and lower levels, sectionalizing switches and user branch line switches adopt two-stage overcurrent protection, namely instantaneous overcurrent protection and time-limited overcurrent protection.

[0035] Step 1: Real-time acquisition of power distribution line tie switch S L The change in position.

[0036] In this embodiment, the real-time reading of the power distribution line interconnection switch S is performed. L The position change. If the contact switch S L If the switch changes from open to closed, proceed to step 2; if the contact switch S L The position changes from a combined position to a separate position, and the process jumps to step 4.

[0037] The adaptive protection of this power distribution line uses the tie switch S L Position change serves as the triggering condition when the contact switch S L When the switch changes from open to closed, it is considered that the operation mode of the power distribution line has been adjusted, and the protection settings of the line switch need to be adaptively adjusted; when the tie switch S L When the switch changes from closed to open, it is considered that the operation mode of the power distribution line has been restored, and the line switch protection needs to return to the set value under normal operation.

[0038] Step 2: If the power distribution line interconnection switch S L To change from a detached to a closed position, iterate through the positions of all substation switches on the corresponding distribution line and assign the number of the substation switch in the detached position to the variable n, thus obtaining the detached switch S. n The substation switches include: outgoing line switches and sectionalizing switches.

[0039] Activate the dynamic position change positioning module for the power distribution line switch. When the power distribution line tie switch S... L After changing from open to closed, the positions of all outgoing switches and sectionalizing switches in the distribution line are traversed. If switch S j The position of (j=0,1,2…) is at the terminating position, so the switch number j is assigned to the variable n.

[0040] ; (1) Where n is the change in switch position, called switch S n It is a terminating switch.

[0041] Step 3: Calculate the setting position of the front-end switch according to the formula x=ni; where x represents the setting position of the front-end switch, and i represents the number of iterations. After each iteration, the i+1 operation is performed.

[0042] When the current section switch setting is equal to 0, the overcurrent protection setting of the outgoing line switch overcurrent protection stage I is calculated by using the method of avoiding the maximum short-circuit current when there is a fault at the end of the line; the overcurrent protection setting of the outgoing line switch overcurrent protection stage II is calculated by using the method of ensuring that the minimum short-circuit current at the end of the line section can be cut off; the overcurrent protection setting of the outgoing line switch overcurrent protection stage III is calculated by using the method of avoiding the maximum load current, thus obtaining the set of outgoing line switch overcurrent protection settings; When the setting value of the upstream sectionalizing switch is greater than 0, the overcurrent protection setting value of stage I of the upstream sectionalizing switch is calculated by using the method of avoiding the maximum short-circuit current during a fault at the end of the line; the formula is then used. Calculate the overcurrent protection settings for stage II of the upstream sectionalizing switch to obtain the set of overcurrent protection settings for the upstream sectionalizing switch; among which, K rel For reliability coefficient, The overcurrent protection setting for stage II of the sectionalizing switch overcurrent protection is set as follows. I Sx_load_max This represents the maximum load current. After obtaining the overcurrent protection setting set of the outgoing line switch and the overcurrent protection setting set of the upstream section switch; using the method of avoiding the maximum short-circuit current when the distribution transformer at the end of the branch line fails, calculate the overcurrent protection setting of the upstream branch line switch I section; using the method of avoiding the maximum load current setting of the branch line, calculate the overcurrent protection setting of the upstream branch line switch II section, and obtain the overcurrent protection setting set of the upstream branch line switch. When the setting value of the current section switch is less than 0, the protection setting value of the subsequent section switch is set to obtain the protection setting value of the subsequent section switch.

[0043] Specifically, in this embodiment, the adaptive setting module for the power distribution line switch protection is activated. The logic block diagram of this module is as follows: Figure 5 As shown. After starting the adaptive setting module for the protection setting of the power distribution line switch, it first enters the front-end switch protection setting module, i.e., step 3.1; after execution, it enters the back-end switch protection setting module, i.e., step 3.2; after the above modules have completed the calculation, they output the protection setting values ​​(overcurrent protection setting values) of each switch.

[0044] Step 3.1: Start the front-end switch protection setting module. The block diagram of this module is as follows: Figure 6 As shown.

[0045] according to Figure 6 Calculate the setting position x of the front-end switch.

[0046] ; (2) S x For the current setting calculation switch of the front section, if x is greater than or equal to 0, jump to step 3.1.2; if x is less than 0, it means that the entire power distribution line is switched to power supply from the opposite side and there is no front section switch, jump to step 3.2.

[0047] Step 3.1.2: (1) If x If the value is 0, determine if S is equal to 0. x The setting calculation method for outgoing line switches in substations is as follows: The outgoing line switch overcurrent protection stage I (this is the common terminology used in the industry for three-stage overcurrent protection, referring to the first, second, and third stages of a three-stage system) is equipped with instantaneous current overcurrent protection. Its purpose is to quickly and reliably clear line outgoing faults. The setting principle is to avoid overcurrent at the end of this stage (D...). x+1 The maximum short-circuit current during a fault (at point 1) is calculated using the following formula: ; (3) In the formula, K rel The reliability coefficient is usually set to 1.3. I D1_fmax This represents the fault current when a three-phase short circuit occurs at node D1. Node D1 is the node where the first sectionalizing switch of the line is located. (See reference...) Figure 3 and Figure 4 .

[0048] To ensure speed, the action time is set to 0 seconds.

[0049] The outgoing line switch overcurrent protection stage II is equipped with time-limited instantaneous overcurrent protection to protect the entire length of this line section. The setting principle is to ensure that the minimum short-circuit current at the end of this line section can be cut off. Therefore, the setting calculation formula is as follows: ; (4) In the formula,K sen The sensitivity coefficient is usually set to 1.5. I D1_fmin This is the fault current when a two-phase short circuit occurs at point D1.

[0050] The overcurrent protection stage II of the outgoing line switch needs to coordinate with the overcurrent protection stage I of the next-level switch. Since the sum of the protection start-up time and the circuit breaker operating time is at least 0.15 seconds, the time interval Δ between the upstream and downstream switch protection actions is necessary. t The maximum value is 0.2s. Therefore, the operating time of the outgoing line switch II protection is 0.2s.

[0051] According to equations (3) and (4), when the outgoing switch is in the position of the terminating switch S... n In the initial stage, the overcurrent protection settings of Stage I and Stage II do not change with the operating mode, so no calculation is required, and the original settings under the normal operating mode are still used.

[0052] The outgoing line switch overcurrent protection stage III is equipped with time-limit overcurrent protection as backup protection for the entire line. The setting principle is to avoid the maximum load current, and the setting calculation formula is as follows: (5) Among them, the maximum load current I S0_load_max The calculation formula is: (6) In the formula, I 0_t The load current flowing through the outgoing switch S0, I n_t For the flow through the divider switch S n The load current is sampled at intervals of 5 minutes, and the sampling range is within this month.

[0053] The protective action time is: (7) According to equations (5)-(7), when the outgoing switch is in the position of the terminating switch S... n In the early stage, the overcurrent protection setting and action time of its third stage will change with the change of operating mode. It needs to be calculated according to formula (5)-(7) and the setting under the original normal operating mode cannot be used.

[0054] (2) If x A value greater than 0 indicates that S x The calculation method for the setting of the sectionalizing switch is as follows: The sectionalizing switch overcurrent protection stage I is equipped with instantaneous overcurrent protection, and the setting principle is to avoid overcurrent protection at the end of this section of the line (D). x+1The formula for calculating the maximum short-circuit current during a fault (at point 1) is as follows: (8) In the formula, I D(x+1)_fmax D x+1 The fault current when a three-phase short circuit occurs at the node, with an operating time of 0 seconds. (D) x+1 The node is the current tuning calculation S of the previous stage. x The node where the next level segment switch is located.

[0055] The second stage of the sectionalizing switch overcurrent protection is equipped with time-limit overcurrent protection. The setting calculation formula is as follows: (9) Among them, the maximum load current I Sx_load_max The calculation formula is: (10) In the formula, I x_t For the flow through the outgoing switch S x Load current, I (x+1)_t For the flow through the divider switch S x+1 The load current is sampled at intervals of 5 minutes, and the sampling range is within this month.

[0056] The protective action time is: (11) Among them, △ t The time interval between the actions of the upstream and downstream switch protection is usually taken as 0.2s.

[0057] (3) Front branch line switch F x The calculation method for setting the fixed value is as follows: The branch line switch overcurrent protection stage I is configured with instantaneous overcurrent protection. The setting principle is to avoid the maximum short-circuit current during a fault in the distribution transformer at the end of the branch line. The setting calculation formula is as follows: (12) In the formula, I Fx_T_fmax The fault current is set to 0s when a three-phase short circuit occurs in the distribution transformer of the end user. The overcurrent protection action time of the branch switch is set to 0s.

[0058] The branch line switch overcurrent protection stage II is configured with time-limit overcurrent protection, set to avoid the maximum load current of the branch line. The calculation formula is as follows: (13) In the formula,I Fx_load_max This represents the maximum load current of the users served by this branch line. The overcurrent protection time of the branch switch needs to be coordinated with the protection time of stage I, so it is set to 0.2s.

[0059] According to equations (8) and (12), when the sectionalizing switch and the branch line switch are located at the position of the sectionalizing switch S... n In the first stage, the overcurrent protection settings of the first stage do not change with the operating mode and do not need to be calculated. The original settings under the normal operating mode are still used. The overcurrent protection settings of the second stage change with the operating mode and need to be set according to formulas (9)-(11) and (13). The original settings under the normal operating mode cannot be used.

[0060] Step 3.1.3: Output the front-end switch protection setting obtained in step 3.1.2 to the protection setting storage module.

[0061] Step 3.2: Start the downstream switch protection setting module. The block diagram of this module is as follows: Figure 7 As shown.

[0062] in, j _max represents the maximum number of segments in the power distribution line.

[0063] Step 3.2.1: According to Figure 7 Calculate the setting position of the downstream switch. y S y This is the current setting calculation switch for the subsequent stage.

[0064] (14) Where m represents the number of iterations. After each iteration, the m+1 operation is performed. In this way, the protection settings of all downstream sectional switches are calculated one by one.

[0065] Step 3.2.2: Calculate the protection setting values ​​for the downstream sectionalizing switch and the branch line switch.

[0066] (1) Rear section sectionalizing switch S y The calculation method for setting the fixed value is as follows: The sectionalizing switch overcurrent protection stage I is equipped with instantaneous current overcurrent protection, and the setting principle is to avoid the maximum short-circuit current during a fault at the end of this section of the line. When the line operation mode is adjusted, switch S... y The switch above the previous level becomes the switch below the previous level after adjustment; therefore, the setting principle is to avoid node D. y-1 (D) y-1 The node (i.e., the node where the upstream sectionalizing switch of the current setting calculation switch Sy is located) is the maximum short-circuit current when a fault occurs. The setting calculation formula is: (15) In the formula, I D(y-1)_fmax D y-1 The fault current when a three-phase short circuit occurs at a node is calculated using the following formula: (16) In the formula, This is a short-circuit type parameter, set to 1 for three-phase short-circuit faults; This is the equivalent phase electromotive force of the power supply system on the opposite side of the power distribution line. The equivalent power supply internal impedance of the system on the opposite side of the power distribution line. The equivalent power source of the system on the opposite side of the distribution line to the tie point D L impedance, Contact point D L To node D y-1 The impedance.

[0067] The overcurrent stage I protection action time is set to 0 seconds. Contact point D. L This refers to the interconnection switch S of the power distribution line. L The node in question.

[0068] The sectionalizing switch overcurrent protection stage II is equipped with time-limit overcurrent protection. The setting principle is to avoid the maximum load current flowing through the sectionalizing switch. The calculation formula is as follows: (17) Among them, the maximum load current I Sx_load_max The calculation formula is: (18) In the formula, I y_t For the flow through the outgoing switch S x Load current, I (y-1)_t For the flow through the divider switch S y-1 The load current is sampled at intervals of 5 minutes.

[0069] The protective action time is: (19) (2) Rear branch line switch F y The calculation method for setting the fixed value is as follows: The branch line switch overcurrent protection stage I is configured with instantaneous overcurrent protection. The setting principle is to avoid the maximum short-circuit current during a fault in the distribution transformer at the end of the branch line. The setting calculation formula is as follows: (20) In the formula, IT_fmax For branch line F y The fault current when a three-phase short circuit occurs at the terminal distribution transformer is calculated using the following formula: ; (twenty one) In the formula, Contact point D L To node D y impedance, For branch line F y The impedance; the branch line Fy is D y Node to D y+1 Branch lines between nodes that supply power to users; D y The node is the current setting calculation switch S in the subsequent stage. y The node, D y+1 The node is the current setting calculation switch S in the subsequent stage. y The node where the next level segment switch is located.

[0070] The overcurrent protection action time of the branch line switch is set to 0 seconds.

[0071] The branch line switch overcurrent protection stage II is configured with time-limit overcurrent protection, set to avoid the maximum load current of the branch line. The calculation formula is as follows: ; (twenty two) The overcurrent protection time of the branch switch needs to be coordinated with the protection time of stage I, so it is set to 0.2s.

[0072] According to equations (15)-(22), when the sectionalizing switch and the branch line switch are located after the sectionalizing switch Sn, the overcurrent protection settings of the sectionalizing switch I and II and the branch line switch I all change. They need to be calculated according to equations (15)-(21) and the original normal operating settings cannot be used. The overcurrent protection setting of the branch line switch II does not change with the operating mode and does not need to be calculated. The original normal operating settings can still be used.

[0073] Step 3.2.3: Output the downstream switch protection setting obtained in step 3.2.2 to the protection setting storage module.

[0074] Step 4: If the power distribution line interconnection switch S L When the position changes from closed to open, the normal operating mode protection settings are retrieved.

[0075] Step 5: Activate the distributed power source verification module for the power distribution line. The working logic of this module is as follows: If the power distribution line does not have a distributed power source, but a distributed power source is available after the mode adjustment, then the protection of the outgoing switches and each section switch of the power distribution line will be locked with directional blocking elements to prevent protection maloperation due to backflow; if the power distribution line has a distributed power source, but a distributed power source is available after the mode adjustment, then the protection of the outgoing switches and each section switch of the power distribution line will be deactivated with directional blocking elements.

[0076] Step 6: Activate the remote download module for power distribution line switch protection settings. This module can retrieve protection settings from the protection setting storage module and send them to the power distribution automation system backend via interface conversion. It automatically transmits the settings to the power distribution switch protection terminal via fiber optic and wireless networks for remote setting verification and configuration, enabling adaptive real-time adjustment of power distribution switch protection settings according to changes in operating mode and power flow.

[0077] This embodiment solves the problem that protection settings cannot be applied under real-time changes in the operating mode and power flow of distribution lines. By real-time analysis of switch positions, online setting calculation, distributed power source verification, and remote setting download, the protection settings are dynamically followed by changes in operating mode and power flow, avoiding the problems of false tripping and failure to trip of distribution line protection, and effectively ensuring the accurate and rapid isolation of faults in distribution networks containing distributed power sources.

[0078] This embodiment achieves coordinated setting of main line and branch line switch protection through three-level switch protection setting calculation of distribution lines. It overcomes the limitation of existing methods that are difficult to apply to complex distribution network structures with multiple segments and connections. Under the trend of increasingly flexible operation mode and increasingly complex topology of distribution network, it effectively ensures the realization of the "four characteristics" of distribution network protection configuration.

[0079] In one exemplary embodiment, a computer device is provided, which may be a server or a terminal, and its internal structure diagram may be as follows. Figure 8As shown, this computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operating system and computer programs stored in the non-volatile storage media. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communicating with external terminals via a network. When the computer program is executed by the processor, it implements an adaptive configuration method for power distribution line protection that matches operating modes and power flow changes.

[0080] Those skilled in the art will understand that Figure 8 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0081] In one exemplary embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0082] In one exemplary embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0083] In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0084] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0085] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).

[0086] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0087] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0088] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for adaptive configuration of distribution line protection to match operating modes and power flow changes, characterized in that, include: Real-time acquisition of power distribution line interconnection switch S L Changes in position; If the power distribution line interconnection switch S L If the position changes from closed to open, the normal operating mode protection settings are retrieved. If the power distribution line interconnection switch S L To change from a detached to a closed position, iterate through the positions of all substation switches on the corresponding distribution line and assign the number of the substation switch in the detached position to the variable n, thus obtaining the detached switch S. n The substation switches include: outgoing line switches and sectionalizing switches; The setting position of the front-end switch is calculated according to the formula x=ni; where x represents the setting position of the front-end switch, and i represents the number of iterations. After each iteration, the i+1 operation is performed. When the current section switch setting is equal to 0, the overcurrent protection setting of the outgoing line switch overcurrent protection stage I is calculated by using the method of avoiding the maximum short-circuit current when there is a fault at the end of the line; the overcurrent protection setting of the outgoing line switch overcurrent protection stage II is calculated by using the method of ensuring that the minimum short-circuit current at the end of the line section can be cut off; the overcurrent protection setting of the outgoing line switch overcurrent protection stage III is calculated by using the method of avoiding the maximum load current, thus obtaining the set of outgoing line switch overcurrent protection settings; When the setting value of the upstream sectionalizing switch is greater than 0, the overcurrent protection setting value of stage I of the upstream sectionalizing switch is calculated by using the method of avoiding the maximum short-circuit current during a fault at the end of the line; the formula is then used. Calculate the overcurrent protection settings for stage II of the upstream sectionalizing switch to obtain the set of overcurrent protection settings for the upstream sectionalizing switch; among which, K rel For reliability coefficient, The overcurrent protection setting for stage II of the sectionalizing switch overcurrent protection is set as follows. I Sx_load_max This represents the maximum load current. After obtaining the overcurrent protection setting set of the outgoing line switch and the overcurrent protection setting set of the upstream section switch; using the method of avoiding the maximum short-circuit current when the distribution transformer at the end of the branch line fails, calculate the overcurrent protection setting of the upstream branch line switch I section; using the method of avoiding the maximum load current setting of the branch line, calculate the overcurrent protection setting of the upstream branch line switch II section, and obtain the overcurrent protection setting set of the upstream branch line switch. When the setting value of the current section switch is less than 0, the protection setting value of the subsequent section switch is set to obtain the protection setting value of the subsequent section switch.

2. The adaptive configuration method for distribution line protection matching operating mode and power flow changes according to claim 1, characterized in that, When the setting value of the current section switch is less than 0, the protection setting value of the subsequent section switch is set to obtain the protection setting value of the subsequent section switch, which specifically includes: The overcurrent protection setting value of section I of the downstream sectionalizing switch is calculated by using the method of avoiding the maximum short-circuit current when there is a fault at the end of the line. The overcurrent protection setting value of the second stage of the overcurrent protection of the downstream sectionalizing switch is calculated by using the method of avoiding the maximum load current flowing through the sectionalizing switch. The overcurrent protection setting value of stage I of the branch line switch is calculated by using the method of avoiding the maximum short-circuit current when the distribution transformer at the end of the branch line fails. By using the method of avoiding the maximum load current of the branch line, the overcurrent protection setting value of the second stage of the overcurrent protection of the downstream branch line switch is calculated.

3. The adaptive configuration method for distribution line protection matching operating mode and power flow changes according to claim 1, characterized in that, Using the method of avoiding the maximum short-circuit current during a fault at the end of the line, the calculation formula for the overcurrent protection setting of section I of the downstream sectionalizing switch is as follows: ； In the formula, K rel The reliability coefficient; I D(y-1)_fmax D y-1 The fault current when a three-phase short circuit occurs at the node; where D y-1 The node is the node of the next-level segment switch of the current setting calculation switch Sy in the subsequent section; The formula for calculating the overcurrent protection setting of the second stage of the sectionalizing switch, by utilizing the method of avoiding the maximum load current flowing through the sectionalizing switch, is as follows: ； in, I Sx_load_max Indicates the maximum load current; The formula for calculating the overcurrent protection setting of stage I of the downstream branch line switch, using the method of avoiding the maximum short-circuit current during a fault in the distribution transformer at the end of the branch line, is as follows: ； In the formula, I Fy_T_fmax This is the fault current when a three-phase short circuit occurs at the distribution transformer at the end of branch line Fy; branch line Fy is D. y Node to D y+1 Branch lines between nodes that supply power to users; D y The node is the current setting calculation switch S in the subsequent stage. y The node, D y+1 The node is the current setting calculation switch S in the subsequent stage. y The node where the next level segment switch is located; Using the method of avoiding the maximum load current of the branch line, the calculation formula for the overcurrent protection setting of the second stage of the branch line overcurrent protection is as follows: ； in, I Fy_load_max This represents the maximum load current flowing through the branch line Fy.

4. The adaptive configuration method for distribution line protection matching operating mode and power flow changes according to claim 1, characterized in that, The formula for calculating the overcurrent protection setting of stage I of the upstream branch line switch, using the method of avoiding the maximum short-circuit current during a fault in the distribution transformer at the end of the branch line, is as follows: ； In the formula, K rel The reliability coefficient; I Fx_T_fmax This refers to the fault current when a three-phase short circuit occurs in the distribution transformer of the end user. Using the method of avoiding the maximum load current setting of the branch line, the calculation formula for the overcurrent protection setting value of the second stage of the upstream branch line switch is as follows: ； In the formula, I Fx_load_max This is the maximum load current for the users connected to this branch line.

5. The adaptive configuration method for distribution line protection matching operating mode and power flow changes according to claim 1, characterized in that, Using the method of avoiding the maximum short-circuit current during a fault at the end of the line, the calculation formula for the overcurrent protection setting of stage I of the line switch is as follows: ； in, K rel The reliability coefficient; I D1_fmax This refers to the fault current when a three-phase short circuit occurs at the first node of a power distribution line segment. Using the method of ensuring the minimum short-circuit current at the end of the line section can be cut off, the calculation formula for the overcurrent protection setting of the line switch overcurrent protection stage II is as follows: ； in, K sen Sensitivity coefficient; I D1_fmin This refers to the fault current when a two-phase short circuit occurs at the first node of a power distribution line segment. Using the method of avoiding the maximum load current, the calculation formula for the overcurrent protection setting of stage III of the line switch overcurrent protection is as follows: ； Among them, the maximum load current I S0_load_max The calculation formula is: ； In the formula, I 0_t The load current flowing through the outgoing switch S0, I n_t This represents the load current flowing through the divider switch Sn.

6. The adaptive configuration method for distribution line protection matching operating mode and power flow changes according to claim 1, characterized in that, The formula for calculating the overcurrent protection setting of stage I of the upstream sectionalizing switch, using the method of avoiding the maximum short-circuit current during a fault at the end of the line, is as follows: ； In the formula, K rel For reliability coefficient, I D(x+1)_fmax This is the fault current when a three-phase short circuit occurs at the end node of the line, and the action time is taken as 0s.

7. The adaptive configuration method for distribution line protection matching operating mode and power flow changes according to claim 1, characterized in that, When the setting value of the current section switch is less than 0, the protection setting value of the subsequent section switch is set. After obtaining the protection setting value of the subsequent section switch, the following steps are also taken: If the power distribution line has no distributed power source, but there is a distributed power source after the mode is adjusted, then the protection of the outgoing switch and each section switch of the power distribution line shall be locked with the direction blocking element. If the power distribution line has distributed power sources, but there are no distributed power sources after the mode is adjusted, then the protection of the outgoing switches and each section switches of the power distribution line shall be locked out of the directional blocking element.

8. A computer device, comprising: A memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that the processor executes the computer program to implement the adaptive configuration method for power distribution line protection that matches the operating mode and power flow changes as described in any one of claims 1-7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the adaptive configuration method for power distribution line protection that matches the operating mode and power flow changes as described in any one of claims 1-7.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the adaptive configuration method for power distribution line protection that matches the operating mode and power flow changes as described in any one of claims 1-7.

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