A method for load transfer in 10kV distribution networks based on big data from the power grid

Abstract

This invention discloses a method for load transfer in a 10kV distribution network based on big data from the power grid, comprising the following steps: determining the type of load to be transferred by the current value of the load to be transferred; obtaining the steady-state load current I of the operating line in the D5000 system. x 66kV main transformer secondary side load current I m The load current to be transferred is I d This method uses numerical comparison to determine the type of load to be transferred: whether the line structure of the load to be transferred meets the load transfer conditions; whether the number of ring network lines and the operational status of the ring network switches can be determined to achieve electrical connection between the line to be transferred and the opposite line, thus determining whether the line structure of the load to be transferred meets the load transfer conditions; whether the opposite line of the receiving load has the load transfer capability; and finally, generating a load transfer scheme. This method can determine the optimal transfer scheme based on the operating status of the line to be transferred, achieving the goal of fast, accurate, economical, and scientific load transfer and restoration.

Description

Technical Field

[0001] This invention relates to a load transfer method, and more particularly to a method for load transfer in a 10kV distribution network based on big data of the power grid. Background Technology

[0002] Distribution network load transfer refers to the allocation and transfer of loads when the power grid is out of service due to faults or temporary maintenance, by changing the grid's wiring and operating modes to ensure that the power supply to the grid loads is not affected. Load restoration refers to the process of restoring the power grid to its original operating mode after the fault is resolved or the work is completed. With the increase in the interconnection rate of distribution network lines and the improvement of distribution network automation, most lines have double-circuit or multi-source interconnection lines. Changes in grid wiring modes have also made load arrangements more flexible and variable. Because of its advantages of ensuring uninterrupted power supply or reducing the duration of power outages, it greatly improves the reliability of power supply, making grid maintenance and fault handling increasingly reliant on grid load transfer and restoration.

[0003] Currently, when performing load transfer operations, distribution dispatchers typically use pre-established load transfer plans or decide on load transfer methods on an ad-hoc basis. This is mainly applicable to single-ring network lines or situations with low interconnectivity, limited load transfer methods, or situations where large-scale transfers are not feasible. However, with the continuous development of distribution networks and the improvement of distribution network automation levels, the interconnectivity of the power grid has increased significantly. This method has gradually revealed some drawbacks and shortcomings. These are mainly due to the periodic, seasonal, and regional characteristics of power grid load changes; at the same time, power grid fault types are random, variable, and complex, making accurate prediction impossible. Therefore, the method of pre-establishing load transfer and restoration plans for different situations is sometimes impossible to implement due to weather, load, and equipment factors. Alternatively, dispatchers may use ad-hoc arrangements, which takes time, affects power outage duration, and is detrimental to the reliability of power supply. Furthermore, the accuracy and timeliness are poor, directly impacting customer satisfaction with electricity use. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a method for load transfer of 10kV distribution networks based on big data of the power grid, which can determine the optimal transfer scheme according to the working status of the line to be transferred, so as to achieve the purpose of fast, accurate, economical and scientific transfer and restoration of load.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for load transfer in a 10kV distribution network based on big data from the power grid includes the following steps:

[0007] 1. Determine the type of load to be transferred by analyzing the current value of the load to be transferred;

[0008] Obtain the steady-state load current I of the operating line in the D5000 system. x 66kV main transformer secondary side load current I m The load current to be transferred is I d The type of load to be transferred is determined by numerical comparison.

[0009] When I d ≤I x Determine whether the load to be transferred is a load on the main line and branch lines or a load on the entire line.

[0010] When I x <I d ≤I m The load to be transferred is determined to be a 10kV busbar;

[0011] 2. Determine whether the structure of the line carrying the load to be transferred meets the conditions for load transfer;

[0012] By determining the number of ring network lines in the line to be transferred and whether the ring network switch is operational, and whether an electrical connection can be achieved between the line to be transferred and the line on the other side, it can be determined whether the structure of the line to be transferred meets the load transfer conditions.

[0013] 2.1 When the type of load to be transferred is the main line and branch line load or the entire line load, the power source point and the number of opposite lines of the line to be transferred are obtained through the power grid control big data of the D5000 system; if the line to be transferred meets the requirement that the number of power source points X≥2 or the number of opposite lines Y≥1, and at the same time the remaining closing times of the ring network switch and disconnector are not zero, then it is determined that the line structure of the load to be transferred has the conditions for load transfer.

[0014] 2.2 When the load to be transferred is a 10kV bus, first make a judgment according to step 2.1 above. If the conditions are met, then obtain the corresponding 66kV substation wiring structure and operation status data through the power grid control big data. If the substation has a single bus with tie line or multiple bus lines operating separately with bus tie switch, then it is determined that its power grid structure has the conditions for load transfer.

[0015] 3. Determine whether the line on the opposite side of the receiving load has the capacity for load transfer;

[0016] 3.1 Line Load Trend Forecast

[0017] Export the load current data curves of the same period of the current day, the previous day, and the previous year for the line A to be transferred and the opposite lines B, C, D... connected to it from the D5000 system. Overlay the load current curves of the previous day and the previous year for the same period of the load current of the line A to be transferred, and then overlay the load current curves of the previous day and the previous year for the same period of the load current of each opposite line to generate average load current curves A1, B1, C1...

[0018] The annual average growth rate (Y%) of distribution network load is obtained through the aforementioned power grid control big data. The average load current curves A1, B1, C1… are analyzed for data growth according to the regional distribution network load annual average growth rate (Y%), and the annual average load current growth values ​​of the lines are calculated as follows:

[0019] I Ainc =I Aavg *Y%;

[0020] I Binc =I Bavg *Y%;

[0021] I Cinc =I Cavg *Y%;……

[0022] Among them: I Aavg I Bavg I Cavg For the annual average load current of lines A, B, and C, respectively, an increase value I is added to the curves A1, B1, C1... Ainc I Binc I Cavg ...and obtain the current load trend prediction curves A2, B2, C2... respectively;

[0023] 3.2 Calculate the peak-valley current interval of the opposite line after load transfer.

[0024] The current load trend prediction curve A2 of the line to be transferred is superimposed with the actual load prediction curve B2 of the opposite line B to obtain the load current prediction curve Z1 after the transfer. The maximum load current I in the next 12 hours is obtained from curve Z1. dmax and minimum load current I dmin After load shift, the peak-valley range of the line current is (I dmin I dmax );

[0025] 3.3 Calculate the load current margin of the opposite line.

[0026] The current carrying capacity I of the cable at the outlet of line B on the opposite side is obtained using the aforementioned power grid control big data. c Minimum wire diameter safety current I x and relay protection setting I j Form a set S = {I} c ,I x ,I j}, set the maximum allowable current of the opposite line B as I. as =MIN(S), where MIN(S) is the minimum value in set S;

[0027] The real-time current I on the secondary side of the main transformer where line B is located is obtained from the aforementioned power grid control big data. z2 and the rated current I of the secondary side of the main transformer an Calculate the residual load current margin I of the main transformer. y =0.8I an -I z2 ;

[0028] 3.4 Determine whether the conditions for generational transition are met.

[0029] If I dmax <I as And I amax <I y If so, it is determined that the opposite line B has the load transfer capability of the line to be transferred, A; amax This represents the maximum load current in curve A2.

[0030] 3.5 Repeat steps 3.2 to 3.4 for the opposite lines C, D... to determine whether the opposite lines C, D... have the load transfer capability for the line A to be transferred;

[0031] 4. Generate load shifting scheme

[0032] 4.1 Further analyze and optimize the lines with load transfer capability selected in step 3. Use the load current value of the line A to be transferred to obtain the load current value in the D5000 system to determine the load status. When the load current value is zero, the load is determined to be in a de-energized state; otherwise, it is in an operating state.

[0033] 4.2 When the line to be transferred, A, is out of power, in order to meet the requirement of restoring power supply as quickly as possible, a short-time and fast transfer scheme should be given priority. The average load transfer time t via the opposite line should be used as a reference quantity. t i The time for each ring network operation command is denoted as n, where n is the number of line ring network switch operations recorded by the D5000 system.

[0034] The average load transfer time for each of the opposite lines B, C, D... is calculated using the above formulas, and a set T = {t} is generated. B ,t C ,t D ...}, select the minimum value t in set T. min The corresponding opposite line is the optimal load transfer scheme;

[0035] 4.3 If the load transfer scheme prioritizes uninterrupted power supply to ensure stable grid operation and reliable power supply to important loads when the line A to be transferred is in operation, the load rate of the opposite line after the transfer will be used as a reference to calculate the maximum load rate L of each opposite line after the load transfer. maxL max =I dmax / I as *100%; I dmax I represents the maximum load current of each opposite line. as This represents the maximum allowable current for each opposite line;

[0036] And generate a set L = {L bmax ,L cmax ,L dmax ...}, select the minimum value L in set L. min The corresponding opposite line is the optimal load transfer scheme.

[0037] The beneficial effects of this invention are as follows:

[0038] 1. The load transfer method of the present invention is based on big data of the power grid, and fully integrates data such as line load, main transformer load, conductor type, cable capacity, load forecast, and relay protection. It takes into account power grid equipment factors and personnel factors, and determines the optimal load transfer scheme through detailed comparison, screening and comprehensive analysis.

[0039] 2. The load transfer method involved in this invention is applicable to load transfer situations in various types of 10kV distribution networks. The operation process is clear and explicit. Based on big data of the power grid, the optimal solution can be determined quickly and accurately through comparison of reference quantities, eliminating the risk of misoperation that may occur when the load transfer solution is determined manually in the traditional method.

[0040] 3. The load transfer method of the present invention has the advantages of quickly and accurately completing load transfer and restoration for different load transfer needs, which greatly shortens the load transfer time in various types and complex situations in the distribution network, improves the safe and stable operation level of the distribution network, and improves the reliability of power supply, thus having good social and economic benefits. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the load curve of the line A to be transferred, which is involved in the present invention.

[0042] Figure 2 This invention relates to a current load trend prediction curve for line A to be transferred.

[0043] Figure 3 This is a schematic diagram of the load curve of the opposite line B involved in the present invention.

[0044] Figure 4 This invention relates to a current load trend prediction curve for the opposite line B.

[0045] Figure 5 This invention relates to a load prediction curve diagram of the opposite side line B after its replacement.

[0046] Figure 6 This is a schematic diagram of the load curve of the opposite line C involved in the present invention.

[0047] Figure 7 This invention relates to a current load trend prediction curve for the opposite line C.

[0048] Figure 8 This invention relates to a load prediction curve diagram of the opposite side line C after its replacement. Detailed Implementation

[0049] The embodiments of this patent are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this patent, and should not be construed as limiting this patent.

[0050] Example 1

[0051] This invention relates to a method for load transfer in a 10kV distribution network based on big data from the power grid, comprising the following steps:

[0052] 1. Determine the type of load to be transferred by analyzing the current value of the load to be transferred;

[0053] Obtain the steady-state load current I of the operating line in the D5000 system. x 66kV main transformer secondary side load current I m The load current to be transferred is I d The type of load to be transferred is determined by numerical comparison.

[0054] When I d ≤I x Determine whether the load to be transferred is a load on the main line and branch lines or a load on the entire line.

[0055] When I x <I d ≤I m The load to be transferred is determined to be a 10kV busbar;

[0056] 2. Determine whether the structure of the line carrying the load to be transferred meets the conditions for load transfer;

[0057] By determining the number of ring network lines in the line to be transferred and whether the ring network switch is operational, and whether an electrical connection can be achieved between the line to be transferred and the line on the other side, it can be determined whether the structure of the line to be transferred meets the load transfer conditions.

[0058] 2.1 When the type of load to be transferred is the main line and branch line load or the entire line load, the power source point and the number of opposite lines of the line to be transferred are obtained through the power grid control big data of the D5000 system; if the line to be transferred meets the requirement that the number of power source points X≥2 or the number of opposite lines Y≥1, and at the same time the remaining closing times of the ring network switch and disconnector are not zero, then it is determined that the line structure of the load to be transferred has the conditions for load transfer.

[0059] 2.2 When the load to be transferred is a 10kV bus, first make a judgment according to step 2.1 above. If the conditions are met, then obtain the corresponding 66kV substation wiring structure and operation status data through the power grid control big data. If the substation has a single bus with tie line or multiple bus lines operating separately with bus tie switch, then it is determined that its power grid structure has the conditions for load transfer.

[0060] 3. Determine whether the line on the opposite side of the receiving load has the capacity for load transfer;

[0061] 3.1 Line Load Trend Forecast

[0062] Export the load current data curves of the same period of the current day, the previous day, and the previous year for the line A to be transferred and the opposite lines B, C, D... connected to it from the D5000 system. Overlay the load current curves of the previous day and the previous year for the same period of the load current of the line A to be transferred, and then overlay the load current curves of the previous day and the previous year for the same period of the load current of each opposite line to generate average load current curves A1, B1, C1...

[0063] The annual average growth rate (Y%) of distribution network load is obtained through the aforementioned power grid control big data. The average load current curves A1, B1, C1… are analyzed for data growth according to the regional distribution network load annual average growth rate (Y%), and the annual average load current growth values ​​of the lines are calculated as follows:

[0064] I Ainc =I Aavg *Y%;

[0065] I Binc =I Bavg *Y%;

[0066] I Cinc =I Cavg *Y%;……

[0067] Among them: I Aavg I Bavg I Cavg For the annual average load current of lines A, B, and C, respectively, an increase value I is added to the curves A1, B1, C1... Ainc I Binc I Cavg...and obtain the current load trend prediction curves A2, B2, C2... respectively;

[0068] 3.2 Calculate the peak-valley current interval of the opposite line after load transfer.

[0069] The current load trend prediction curve A2 of the line to be transferred is superimposed with the actual load prediction curve B2 of the opposite line B to obtain the load current prediction curve Z1 after the transfer. The maximum load current I in the next 12 hours is obtained from curve Z1. dmax and minimum load current I dmin After load shift, the peak-valley range of the line current is (I dmin I dmax );

[0070] 3.3 Calculate the load current margin of the opposite line.

[0071] The current carrying capacity I of the cable at the outlet of line B on the opposite side is obtained using the aforementioned power grid control big data. c Minimum wire diameter safety current I x and relay protection setting I j Form a set S = {I} c ,I x ,I j}, set the maximum allowable current of the opposite line B as I. as =MIN(S), where MIN(S) is the minimum value in set S;

[0072] The real-time current I on the secondary side of the main transformer where line B is located is obtained from the aforementioned power grid control big data. z2 and the rated current I of the secondary side of the main transformer an Calculate the residual load current margin I of the main transformer. y =0.8I an -I z2 ;

[0073] 3.4 Determine whether the conditions for generational transition are met.

[0074] If I dmax <I as And I amax <I y If so, it is determined that the opposite line B has the load transfer capability of the line to be transferred, A; amax This represents the maximum load current in curve A2.

[0075] 3.5 Repeat steps 3.2 to 3.4 for the opposite lines C, D... to determine whether the opposite lines C, D... have the load transfer capability for the line A to be transferred;

[0076] 4. Generate load shifting scheme

[0077] 4.1 Further analyze and optimize the lines with load transfer capability selected in step 3. Use the load current value of the line A to be transferred to obtain the load current value in the D5000 system to determine the load status. When the load current value is zero, the load is determined to be in a de-energized state; otherwise, it is in an operating state.

[0078] 4.2 When the line to be transferred, A, is out of power, in order to meet the requirement of restoring power supply as quickly as possible, a short-time and fast transfer scheme should be given priority. The average load transfer time t via the opposite line should be used as a reference quantity. t i The time for each ring network operation command is denoted as n, where n is the number of line ring network switch operations recorded by the D5000 system.

[0079] The average load transfer time for each of the opposite lines B, C, D... is calculated using the above formulas, and a set T = {t} is generated. B ,t C ,t D ...}, select the minimum value t in set T. min The corresponding opposite line is the optimal load transfer scheme;

[0080] 4.3 If the load transfer scheme prioritizes uninterrupted power supply to ensure stable grid operation and reliable power supply to important loads when the line A to be transferred is in operation, the load rate of the opposite line after the transfer will be used as a reference to calculate the maximum load rate L of each opposite line after the load transfer. max L max =I dmax / I as *100%; I dmax I represents the maximum load current of each opposite line. as This represents the maximum allowable current for each opposite line;

[0081] And generate a set L = {L bmax ,L cmax ,L dmax ...}, select the minimum value L in set L. min The corresponding opposite line is the optimal load transfer scheme.

[0082] Example 2

[0083] This example illustrates a scenario where a fault occurs in line A, necessitating a load transfer.

[0084] 1. Determine the type of load to be transferred by analyzing the current value of the load to be transferred;

[0085] Obtain the steady-state load current I of the operating line in the D5000 system. x =221A, 66kV main transformer secondary side load current Im =536A, the current of the load to be transferred is I d =221A, through numerical comparison, since I d =I x Therefore, the type of load to be transferred is determined to be either the load of the main line and branch lines or the load of the entire line.

[0086] 2. Determine whether the structure of the line carrying the load to be transferred meets the conditions for load transfer;

[0087] 2.1 The load type to be transferred is the main line and branch line load or the entire line load. The number of power source points of the line to be transferred is 2 and the number of opposite lines is 2, which is obtained from the power grid control big data of the D5000 system. Since the line to be transferred meets the requirement of power source point X≥2 or opposite line Y≥1; at the same time, the number of remaining ring network switch operations between line A and opposite line B is 23, and the number of remaining ring network switch operations between line A and opposite line C is 31. The remaining number of closing operations of the ring network switch and disconnector is not zero, which means that line A to be transferred has the structural conditions for load transfer.

[0088] 3. Determine whether the line on the opposite side of the receiving load has the capacity for load transfer;

[0089] 3.1 Line Load Trend Forecast

[0090] Export the load current data curves for the same period of the current day, the previous day, and the previous year for line A to be transferred and its two connected opposite lines B and C from the D5000 system. Average the load current curves for the previous day and the previous year for line A, and then average the load current curves for the previous day and the previous year for lines B and C respectively to generate average load current curves A1, B1, and C1. See below for details. Figure 1 , Figure 3 and Figure 6 As shown;

[0091] By obtaining the annual average growth rate of distribution network load Y% = 2.3% through big data analysis of power grid regulation, the average load curves A1, B1, and C1 are analyzed according to the regional distribution network load annual average growth rate of 2.3%, and the annual average load current growth values ​​of the lines are calculated as follows:

[0092] I Ainc =I Aavg* Y% = 235 * 2.3% = 5.05A;

[0093] I Binc =I Bavg *Y%=189*2.3%=4.35A;

[0094] I Cinc =ICavg *Y%176*2.3%=4.05A;

[0095] Among them: I Aavg I Bavg I Cavg For the annual average load current of lines A, B, and C, add I to the curves A1, B1, and C1. Ainc =5.05A, I Binc =4.35A, I Cavg =4.05A growth value, respectively, to obtain the current load trend prediction curves A2, B2, and C2; as Figure 2 , Figure 4 and Figure 7 As shown;

[0096] 3.2 Calculate the peak-valley current interval of the opposite line after load transfer.

[0097] The current load trend prediction curve A2 of the line to be transferred is superimposed with the actual load prediction curve B2 of the opposite line B to obtain the load current prediction curve Z1 after the transfer, as shown below. Figure 5 As shown; obtain the maximum load current I in the next 12 hours from curve Z1. dmax =396A, obtain the minimum load current I in curve Z1. dmin =114A, the peak-valley range of the line current after load shift is (I dmin I dmax ) = (114, 396);

[0098] 3.3 Calculate the load current margin of the opposite line.

[0099] The large dataset is used to obtain the current carrying capacity I of the cable at the B outlet of the opposite line. c =450, minimum wire diameter safe current I x =430A, and relay protection setting I j =425A, forming the set S = {I c ,I x ,I j}={450, 430, 425}, set the maximum allowable current of the opposite line B to I. as =MIN(S)=425A;

[0100] The real-time current I on the secondary side of the main transformer where line B is located is obtained from the power grid control big data. z2 =503 and rated current I on the secondary side of the main transformer an =1025, calculate the residual load current margin I of the main transformer. y =0.8I an -I z2=0.8*1025-503=317A;

[0101] 3.4 Determine whether the conditions for generational transition are met.

[0102] Because of I dmax =396<I as =425andI amax =238A<I y =317A, then it is determined that the opposite line B has the load transfer capability of the line to be transferred, A; I amax This represents the maximum load current in curve A2.

[0103] 3.5. Repeat steps 3.2 to 3.4 for the opposite line C to obtain the converted load current prediction curve Z2, as follows. Figure 8 As shown; the peak-valley range of the line current after load transition is obtained from the load current prediction curve Z2 as (I dmin I dmax ) = (99, 339);

[0104] The current carrying capacity I of the cable at the C outlet of the opposite line is obtained using the big data. c =550, minimum wire diameter safe current I x =430A, and relay protection setting I j =450A, forming the set S = {I c ,I x ,I j If}={550, 430, 450}, then the maximum allowable current of the opposite line C is set to I. as =MIN(S)=430A;

[0105] The real-time current I on the secondary side of the main transformer where line C is located is obtained from the power grid control big data. z2 =625 and the rated current I of the secondary side of the main transformer an =1550, calculate the residual load current margin I of the main transformer. y =0.8I an -I z2 =0.8*1550-625=615A;

[0106] Because of I dmax =396<I as =430andI amax =238A<I y =615A, then it is determined that the opposite line C has the load transfer capability of the line to be transferred, A; I amax This represents the maximum load current in curve A2.

[0107] 4. Generate load shifting scheme

[0108] 4.1 Further analyze and optimize the lines with load transfer capability selected in step 3. Obtain the load current value of the line to be transferred, which is zero, through the D5000 system, and determine that the load is in a de-energized state.

[0109] 4.2 To meet the requirement of restoring power supply as quickly as possible, a short-time, rapid transfer scheme should be prioritized, using the average load transfer time t via the opposite line as a reference value. t i The time for each ring network operation command is denoted as n, where n is the number of line ring network switch operations recorded by the D5000 system.

[0110] Calculate the average load transfer time for line B.

[0111] Average load transfer time of line C

[0112] The average load transfer time for each opposite line B and C is calculated using the above formulas, and a set T = {t} is generated. B ,t C Given set T = {12.37, 15.23}, select the minimum value t in set T. min Line B on the opposite side, corresponding to 12.37 min, is selected as the optimal load transfer scheme.

[0113] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for load transfer in a 10kV distribution network based on big data from the power grid, comprising the following steps: (1) Determine the type of load to be transferred by the current value of the load to be transferred; Obtain the steady-state load current I of the operating line in the D5000 system. x 66kV main transformer secondary side load current I m The load current to be transferred is I d The type of load to be transferred is determined by numerical comparison. When I d ≤I x Determine whether the load to be transferred is a load on the main line and branch lines or a load on the entire line. When I x <I d ≤I m The load to be transferred is determined to be a 10kV busbar; (2) Determine whether the structure of the line to be transferred has the conditions for load transfer; By determining the number of ring network lines in the line to be transferred and whether the ring network switch is operational, and whether an electrical connection can be achieved between the line to be transferred and the line on the other side, it can be determined whether the structure of the line to be transferred meets the load transfer conditions. 2.1 When the type of load to be transferred is the main line and branch line load or the entire line load, the power source point and the number of opposite lines of the line to be transferred are obtained through the power grid control big data of the D5000 system; if the line to be transferred meets the requirement that the number of power source points X≥2 or the number of opposite lines Y≥1, and at the same time the remaining closing times of the ring network switch and disconnector are not zero, then it is determined that the line structure of the load to be transferred has the conditions for load transfer. 2.2 When the load to be transferred is a 10kV bus, first make a judgment according to step 2.1 above. If the conditions are met, then obtain the corresponding 66kV substation wiring structure and operation status data through the power grid control big data. If the substation has a single bus with tie line or multiple bus lines operating separately with bus tie switch, then it is determined that its power grid structure has the conditions for load transfer. (3) Determine whether the line on the other side of the receiving load has the capacity for load transfer; 3.1 Line Load Trend Forecast Export the load current data curves of the same period of the current day, the previous day, and the previous year for the line A to be transferred and the opposite lines B, C, D... connected to it from the D5000 system. Overlay the load current curves of the previous day and the previous year for the same period of the load current of the line A to be transferred, and then overlay the load current curves of the previous day and the previous year for the same period of the load current of each opposite line to generate average load current curves A1, B1, C1... The annual average growth rate (Y%) of distribution network load is obtained through the aforementioned power grid control big data. The average load current curves A1, B1, C1… are analyzed for data growth according to the regional distribution network load annual average growth rate (Y%), and the annual average load current growth values ​​of the lines are calculated as follows: I Ainc =I Aavg *Y%; I Binc =I Bavg *Y%; I Cinc =I Cavg *Y%;…… Among them: I Aavg I Bavg I Cavg For the annual average load current of lines A, B, and C, respectively, an increase value I is added to the curves A1, B1, C1... Ainc I Binc I Cavg ...and obtain the current load trend prediction curves A2, B2, C2... respectively; 3.2 Calculate the peak-valley current interval of the opposite line after load transfer. The current load trend prediction curve A2 of the line to be transferred is superimposed with the actual load prediction curve B2 of the opposite line B to obtain the load current prediction curve Z1 after the transfer. The maximum load current I in the next 12 hours is obtained from curve Z1. dmax and minimum load current I dmin After load shift, the peak-valley range of the line current is (I dmin I dmax ); 3.3 Calculate the load current margin of the opposite line. The current carrying capacity I of the cable at the outlet of line B on the opposite side is obtained using the aforementioned power grid control big data. c Minimum wire diameter safety current I x and relay protection setting I j Form a set S = {I} c ,I x ,I j }, set the maximum allowable current of the opposite line B as I. as =MIN(S), where MIN(S) is the minimum value in set S; The real-time current I on the secondary side of the main transformer where line B is located is obtained from the aforementioned power grid control big data. z2 and the rated current I of the secondary side of the main transformer an Calculate the residual load current margin I of the main transformer. y =0.8I an -I z2 ; 3.4 Determine whether the conditions for generational transition are met. If I dmax <I as And I amax <I y If so, it is determined that the opposite line B has the load transfer capability of the line to be transferred, A; amax This represents the maximum load current in curve A2. 3.5 Repeat steps 3.2 to 3.4 for the opposite lines C, D... to determine whether the opposite lines C, D... have the load transfer capability for the line A to be transferred; (4) Generate load shifting scheme 4.1 Further analyze and optimize the lines with load transfer capability selected in step (3). Obtain the load current value of the line to be transferred A through the D5000 system to determine the status of the load to be transferred. When the load current value is zero, the load is determined to be in a de-energized state; otherwise, it is in an operating state. 4.2 When the line to be transferred, A, is out of power, in order to meet the requirement of restoring power supply as quickly as possible, a short-time and fast transfer scheme should be given priority. The average load transfer time t via the opposite line should be used as a reference quantity. t i The time for each ring network operation command is denoted as n, where n is the number of line ring network switch operations recorded by the D5000 system. The average load transfer time for each of the opposite lines B, C, D... is calculated using the above formulas, and a set T = {t} is generated. B ,t C ,t D ...}, select the minimum value t in set T. min The corresponding opposite line is the optimal load transfer scheme; 4.3 If the load transfer scheme prioritizes uninterrupted power supply to ensure stable grid operation and reliable power supply to important loads when the line A to be transferred is in operation, the load rate of the opposite line after the transfer will be used as a reference to calculate the maximum load rate L of each opposite line after the load transfer. max L max =I dmax / I as *100%; I dmax I represents the maximum load current of each opposite line. as This represents the maximum allowable current for each opposite line; And generate a set L = {L bmax ,L cmax ,L dmax ...}, select the minimum value L in set L. min The corresponding opposite line is the optimal load transfer scheme.

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