Load transfer decision-making method for global optimal configuration of distribution network restoration resources

Abstract

The present invention discloses a load transfer decision method for the global optimal configuration of distribution network restoration resources, which adjusts the available power capacity and its distribution by optimizing the load transfer scheme. According to whether a load outage occurs during the load transfer operation, it can be divided into load hot reversal and load cold reversal: during hot reversal, two live areas are first paralleled, and then the loop is opened at an appropriate position to transfer the load from the original live area to another live area or other branches of the current live area. During this period, the load is not outage. The parallel operation of the distribution network live areas powered by different TBs in the same partition of the transmission network belongs to the closed loop operation; during cold reversal, the load is first cut off and then put into the opposite end live area. The present invention proposes a load transfer decision method for the global optimal configuration of distribution network restoration resources. By determining a feasible load transfer scheme, the topological structure of the relevant live areas is coordinated and optimized, and the global recovery benefit of the distribution network is improved.

Description

Technical Field

[0001] The present invention relates to a load transfer decision method for global optimal configuration of distribution network restoration resources, and belongs to the technical field of distribution network restoration control. Background Art

[0002] The goal of distribution network restoration control is to quickly, safely, and economically restore power after a power outage, minimizing load losses. Rapid restoration of large-scale power outages requires comprehensive consideration of the transmission network's downstream power at each busbar interface, the distribution network's internal power sources, and the microgrids themselves, forming multiple independent restoration sub-areas. These sub-areas are restored concurrently and deployed in parallel as appropriate to continuously expand the restoration scope. This division of restoration sub-areas aligns the available power sources in the distribution network with the targets to be restored. The available capacity, operating mode, and topology of the power sources in the live area influence their ability to restore the loads to be restored.

[0003] Distribution networks are generally designed with closed loops and operate in open loops. If live areas are supplied by the transmission network, the various live areas supplied by the transmission network often cannot be interconnected and operated normally on the distribution network side. The time-varying nature of the distribution network's load capacity, load unit recovery value, and transmission power transmission plans, as well as the uncertainty of the recovery process, can lead to a mismatch between available power sources, distribution networks, and load demand during power outages. For example, during the distribution network recovery process, it is inevitable that live areas will experience insufficient or unbalanced available power, and that transmission channels within the live areas may be overloaded. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a load transfer decision method for the global optimization configuration of distribution network restoration resources, optimize the load transfer plan with smaller load power outage losses, and optimize the allocation of available power capacity from a global perspective based on real-time power outage scenarios.

[0005] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0006] In a first aspect, the present invention provides a load transfer decision method for global optimal configuration of distribution network restoration resources, comprising:

[0007] Step 1: Determine the power supply range of each electrified area and calculate the load transfer operation demand index TN of each electrified area;

[0008] Step 2: TN is greater than the preset threshold TN J (TN J >0) are added to the charged area set Ω for which the decision on the live load transfer is to be made. PD ={PD i |i=1,2,...,N PD}, where PD iis the i-th charged region, N PD is Ω PD Total number of medium charged areas;

[0009] Step 3: If Ω PD If it is an empty set, end this process, otherwise go to step 4;

[0010] Step 4: Determine Ω PD The largest charged area PD in TN i (1≤i≤N PD ), generate PD i The set of disconnectable branches Ω C ={C b |b=1,2,...,N C}, C b is Ω C The bth branch can be disconnected, N C Is the total number of disconnectable branches; if Ω C Is an empty set, corresponding to PD i From Ω PD Remove it and go to step 3, otherwise set b = 1 and go to step 5;

[0011] Step 5: Simulate disconnection of Ω C The bth disconnectable branch in the network generates a set of candidate power paths that meet the safety constraints for the sub-energized area to be transferred corresponding to the bth disconnectable branch. RT,b ={RT b,k |k=1,2,...,N RT,b} and its corresponding opposite end charged area set Ω OD ={OD k |k=1,2,...,N RT,b}, where RT b,k is Ω RT,b The kth candidate power path in N RT,b is Ω RT,b The total number of candidate power paths in OD k is Ω OD The kth opposite end charged area, OD k Is with Ω RT,b The kth candidate power path RT in b,k The only corresponding opposite end charged area, if Ω RT,b If it is an empty set, go to step 7, otherwise go to step 6;

[0012] Step 6: Deducing the scenarios after the transfer of the electrified sub-areas to be transferred according to each candidate power acquisition path, determining the hot and cold switching schemes during the transfer process, and updating the power supply range of each electrified area of the distribution network system and its load transfer operation demand index for each post-transfer scenario; selecting the TN Δ1The candidate power acquisition path and the opposite end powered area that are the smallest and smaller than the preset threshold are used to generate a transfer plan for the sub-powered area to be transferred;

[0013] Step 7: Let b = b + 1, if b > N C , then go to step 8, otherwise go to step 5;

[0014] Step 8: From PD i Among all the transfer schemes of the sub-charged areas to be transferred, select the one that uses TN Δ2 The largest value greater than the preset threshold is used as PD i If there is such a plan, add it to the transfer plan of the sub-charged area to be transferred and go to step 1. If there is no such plan, add PD i From Ω PD Remove from the list and go to step 3.

[0015] Furthermore, in step 1, the calculation formula of the load transfer operation demand index TN is as follows:

[0016]

[0017] Where, γ Lj is the unit power outage loss of the load to be restored at load node j, is the capacity of the load to be restored at load node j, is the available power that load node j can obtain from the energized area of the distribution network is the power available to load node j; N J is the total number of load nodes to be restored within the power supply range of the electrified area, and j is the sequence number of the load nodes to be restored within the power supply range of the electrified area.

[0018] Furthermore, the γ Lj The value of is the maximum value of the load unit power outage loss within the range from the restoration decision moment to the evaluation end moment.

[0019] Furthermore, the The value of is the maximum value of the load restoration demand within the range from the restoration decision moment to the evaluation end moment.

[0020] Furthermore, the N J This includes power-off load nodes and energized load nodes that still require load restoration.

[0021] Furthermore, the available power that can be obtained from the power distribution network is The load nodes within the power supply range of the live area need to be sorted in descending order according to the unit power outage loss of the load to be restored, and the available power of the live area of the distribution network is allocated to each load node in sequence under the premise of meeting the power flow balance constraint, steady-state safety constraint, and topology constraint of the live area;

[0022] The available power of the live area of the distribution network is the sum of the power supply plan of the transmission network, the spinning reserve capacity of the live area of the distribution network and the capacity of the units being restored, and is determined by the maximum value within the range from the restoration decision time to the evaluation end time.

[0023] Furthermore, in step 6, TN Δ1 The calculation formula is as follows:

[0024]

[0025] Where, LO is the increase in the load transfer operation demand index of the opposite end energized area after the load transfer simulation is executed when considering load transfer from any power path; RT is the transfer cost of load transfer from the power acquisition path.

[0026] Furthermore, in step 6, if the path is not unique, the power-obtaining path and the opposite-end energized area with the smallest load transfer operation demand index of the opposite-end energized area are selected.

[0027] Furthermore, in step 6, the hot switching and cold switching schemes are divided according to whether a power outage will occur during the transfer of the load from the original live area to the opposite live area; during hot switching, the two live areas are first closed, and then the loop is opened at an appropriate position so that the load is supplied by the opposite live area. There is no power outage during the load transfer process, but the closing conditions must be met: the effective value of the steady-state current after closing is not allowed to exceed the maximum allowable current carrying capacity of the feeder, and the transient process of closing does not cause the current protection to operate; hot switching is only selected when the phase sequence at both ends of the closing point is consistent and they are powered by the same bus or different bus power supplies running in parallel. The load cold switching is to first cut off the load and then put it into the opposite live area. The load power outage loss generated during the operation is calculated according to the unit power outage loss of the load and the load power supply stoppage power supply by the following formula:

[0028]

[0029] Where t0 is the time when the load starts to recover, t e is the preset evaluation end time; γ(t), ΔP L (t) are the unit power outage loss and active capacity of the restored load at time t, respectively.

[0030] Furthermore, in step 8, TN Δ2 The calculation formula is as follows:

[0031]

[0032] Where, This is the reduction in the load transfer operation demand index of the local energized area when considering load transfer from any power-obtaining path.

[0033] In a second aspect, the present invention provides a load transfer decision-making device for global optimal configuration of distribution network restoration resources, comprising:

[0034] The demand index calculation module is used to determine the power supply range of each electrified area and calculate the load transfer operation demand index TN of each electrified area;

[0035] Add a module to set TN to be greater than the preset threshold TN J (TN J >0) are added to the charged area set Ω for which the decision on the live load transfer is to be made. PD ={PD i |i=1,2,...,N PD}, where PD i is the i-th charged region, N PD is Ω PD Total number of medium charged areas;

[0036] The process end module is used to judge Ω PD If the set is empty, the process ends; otherwise, it goes to the disconnectable branch set generation module;

[0037] The disconnectable branch set generation module is used to determine Ω PD The largest charged area PD in TN i (1≤i≤N PD ), generate PD i The set of disconnectable branches Ω C ={C b |b=1,2,...,N C}, C b is Ω C The bth branch can be disconnected, N C Is the total number of disconnectable branches; if Ω C Is an empty set, corresponding to PD i From Ω PD If it is eliminated, go to the process end module, otherwise set b=1 and go to the simulation module;

[0038] Simulation module, used to simulate disconnection of Ω C The bth disconnectable branch in the network generates a set of candidate power paths that meet the safety constraints for the sub-energized area to be transferred corresponding to the bth disconnectable branch. RT,b ={RT b,k|k=1,2,...,N RT,b} and its corresponding opposite end charged area set Ω OD ={OD k |k=1,2,...,N RT,b}, where RT b,k is Ω RT,b The kth candidate power path in N RT,b is Ω RT,b The total number of candidate power paths in OD k is Ω OD The kth opposite end charged area, OD k Is with Ω RT,b The kth candidate power path RT in b,k The only corresponding opposite end charged area, if Ω RT,b If it is an empty set, it will go to the judgment module, otherwise it will go to the transfer plan generation module;

[0039] The transfer scheme generation module is used to deduce the scenarios after the transfer of the electrified sub-area to be transferred according to each candidate power acquisition path, determine the hot and cold transfer schemes during the transfer process, and update the power supply range of each electrified area of the distribution network system and its load transfer operation demand index for each post-transfer scenario; select the TN Δ1 The candidate power acquisition path and the opposite end powered area that are the smallest and smaller than the preset threshold are used to generate a transfer plan for the sub-powered area to be transferred;

[0040] Judgment module, used to set b=b+1, if b>N C , then go to step 8, otherwise go to the simulation module;

[0041] Transfer plan selection module, used to select i Among all the transfer schemes of the sub-charged areas to be transferred, select the one that uses TN Δ2 The largest value greater than the preset threshold is used as PD i If there is such a plan, add it to the transfer plan of the sub-charged area to be transferred and transfer it to the demand index calculation module. If it does not exist, add PD i From Ω PD Remove it and go to the process end module.

[0042] Furthermore, in the demand index calculation module, the calculation formula of the load transfer operation demand index TN is as follows:

[0043]

[0044] Where, γ Lj is the unit power outage loss of the load to be restored at load node j, is the capacity of the load to be restored at load node j, is the available power that load node j can obtain from the energized area of the distribution network is the power available to load node j; N J is the total number of load nodes to be restored within the power supply range of the electrified area, and j is the sequence number of the load nodes to be restored within the power supply range of the electrified area.

[0045] Furthermore, in the demand index calculation module, the γ Lj The value of is the maximum value of the load unit power outage loss within the range from the restoration decision moment to the evaluation end moment.

[0046] Furthermore, in the demand index calculation module, the The value of is the maximum value of the load restoration demand within the range from the restoration decision moment to the evaluation end moment.

[0047] Furthermore, in the demand index calculation module, the N J This includes power-off load nodes and energized load nodes that still require load restoration.

[0048] Furthermore, in the demand index calculation module, the available power that can be obtained from the electrified area of the distribution network for the load node j is The load nodes within the power supply range of the live area need to be sorted in descending order according to the unit power outage loss of the load to be restored, and the available power of the live area of the distribution network is allocated to each load node in sequence under the premise of meeting the power flow balance constraint, steady-state safety constraint, and topology constraint of the live area;

[0049] The available power of the live area of the distribution network is the sum of the power supply plan of the transmission network, the spinning reserve capacity of the live area of the distribution network and the capacity of the units being restored, and is determined by the maximum value within the range from the restoration decision time to the evaluation end time.

[0050] Furthermore, in the transfer scheme generation module, TN Δ1 The calculation formula is as follows:

[0051]

[0052] Where, LO is the increase in the load transfer operation demand index of the opposite end energized area after the load transfer simulation is executed when considering load transfer from any power path; RT is the transfer cost of load transfer from the power acquisition path.

[0053] Furthermore, in the transfer plan generation module, if the path is not unique, the power-obtaining path and the opposite-end energized area with the smallest load transfer operation demand index are selected.

[0054] Furthermore, in the transfer scheme generation module, the hot switching and cold switching schemes are divided according to whether a power outage will occur during the transfer of the load from the original live area to the opposite live area; during hot switching, the two live areas are first closed, and then the loop is opened at an appropriate position so that the load is supplied by the opposite live area. There is no power outage during the load transfer process, but the closing conditions must be met: the effective value of the steady-state current after closing is not allowed to exceed the maximum allowable current carrying capacity of the feeder, and the transient process of closing does not cause the current protection to operate; hot switching is only selected when the phase sequence at both ends of the closing point is consistent and they are powered by the same bus or different bus power supplies running in parallel. The load cold switching is to first cut off the load and then put it into the opposite live area. The load power outage loss generated during the operation is calculated according to the unit power outage loss of the load and the load power supply stoppage power supply by the following formula:

[0055]

[0056] Where t0 is the time when the load starts to recover, t e is the preset evaluation end time; γ(t), ΔP L (t) are the unit power outage loss and active capacity of the restored load at time t, respectively.

[0057] Furthermore, in the transfer scheme selection module, TN Δ2 The calculation formula is as follows:

[0058]

[0059] Where, This is the reduction in the load transfer operation demand index of the local energized area when considering load transfer from any power-obtaining path.

[0060] Compared with the prior art, the present invention has the following beneficial effects:

[0061] This invention provides a load transfer decision-making method for globally optimizing the allocation of distribution network restoration resources. Based on real-time power outage scenarios, it proposes improving the matching of restored supply and demand by changing the operating mode of energized areas. Based on a load transfer operation desirability index, it optimizes load transfer plans globally to minimize load outage losses. This method also optimizes the allocation of available power capacity from a global perspective based on real-time power outage scenarios. This method effectively accelerates the restoration process and reduces losses from power outages. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 This is a schematic diagram of the local topology of a distribution network provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0063] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0064] Example 1

[0065] This embodiment introduces a load transfer decision-making method for global optimal configuration of distribution network restoration resources, including:

[0066] The distribution network is usually designed for open-loop operation, and only short-term electromagnetic loops are allowed during the closing and opening operations without interrupting the load. Therefore, during the restoration decision-making process, although the restoration demand satisfaction rate (the ratio of the TB available power to all the net loads to be restored that are uniquely attributed to the TB) of each transmission network interface busbar (TB) varies greatly, under the constraints of the radial network topology, the energized domains supplied by the transmission network cannot be interconnected on the distribution network side, resulting in a blockage of the transmission network power supply. As shown in the attached figure Figure 1 In the case where the available power of TB2 is insufficient to restore the nodes 1-6 to which the electrified area is subject to mandatory restoration, if nodes 7-13 are adjusted to TB1 or TB3 with sufficient available power, the distribution network as a whole can restore more loads and have a greater ability to receive power from the transmission network.

[0067] Based on the real-time power outage scenario, the present invention proposes a load transfer optimization method for the effective utilization of distribution network restoration resources. Based on the real-time power outage scenario, the method further optimizes the allocation of available power capacity from a global perspective, changes the operating mode of the live zone through the switching operation, and avoids the irrational distribution network topology from hindering the improvement of global restoration benefits. The present invention adjusts the available power capacity and its distribution by optimizing the load transfer scheme. Depending on whether a load outage occurs during the load transfer operation, it can be divided into load hot switching and load cold switching: during hot switching, two live zones are first paralleled, and then the loop is opened at an appropriate position to transfer the load from the original live zone to another live zone or other branches of the current live zone. During this period, the load is not shut down. The parallel operation of the distribution network live zones powered by different TBs in the same partition of the transmission network is a closed loop operation; during cold switching, the load is first cut off and then put into the opposite end live zone. The load outage loss generated during the operation is calculated according to the unit outage loss of the load and the load power supply stoppage power supply by formula (1). The evaluation time is the total time consumed by all load switching operations in the distribution network. Hot switching should be prioritized, but the following conditions must also be met: the phase sequence at both ends of the loop closing point is consistent, and the maximum allowable voltage and phase angle differences do not exceed preset thresholds. If a DG is present in the load subtree to be switched, the load switching operation must also meet multi-source networking requirements, including a feasible voltage / frequency coordinated control mode between the sources, protection configuration requirements, and an operating mode that passes safety verification.

[0068]

[0069] Where t0 is the time when the load starts to recover, t e is the preset evaluation end time; γ(t), ΔP L (t) are the unit power outage loss and active capacity of the restored load at time t, respectively. Both are affected by factors such as power outage duration, external environment, and user type.

[0070] The present invention provides a load transfer decision method for global optimal configuration of distribution network restoration resources, which specifically includes the following steps:

[0071] Step 1: Determine the power supply range of each live area according to existing methods. The power supply range and restoration sub-area both refer to the set of power equipment and loads that are out of service but can be restored. Calculate the load transfer operation demand index of each live area. The calculation of the load transfer operation demand index TN of the live area during the restoration process is shown in formula (2).

[0072]

[0073] Where, γ Lj is the unit power outage loss of the load to be restored at load node j. Considering the time-varying nature of the unit power outage loss of the load, it is taken as the maximum value of the unit power outage loss of the load within the range from the restoration decision moment to the evaluation end moment; is the capacity of the load to be restored at load node j. Considering the time-varying nature of load restoration demand, it is taken as the maximum value of the load restoration demand from the restoration decision moment to the evaluation end moment; is the incremental power that load node j can obtain from the electrified area. To this end, it is necessary to sort the load nodes within the power supply range of the electrified area in descending order according to the unit power outage loss of the load to be restored. Under the premise of meeting the safety constraints such as the electrified area flow balance constraint, steady-state safety constraint, and topology constraint, the available power of the electrified area is allocated to each load node in turn. The power that load node j can obtain is N J = is the total number of load nodes to be restored within the power supply range of the energized zone, including both outages and energized load nodes that still require restoration. j is the sequence number of the load nodes to be restored within the power supply range of the energized zone. Considering the time-varying nature of the distribution network's power output capacity due to factors such as the instability of intermittent power output and the adjustability of the transmission network's power delivery plan, the available power within the energized zone of the distribution network is determined by taking into account the maximum value between the time of restoration decision and the end of the evaluation, based on the sum of the transmission network's power delivery plan, the spinning reserve capacity within the energized zone, and the capacity of the units undergoing restoration.

[0074] Step 2: The load transfer operation demand index TN is greater than the preset threshold TN J (TN J>0) are added to the charged area set Ω for which the decision on the live load transfer is to be made. PD ={PD i |i=1,2,...,N PD}.

[0075] Step 3: If Ω PD If it is an empty set, end this process, otherwise go to step 4.

[0076] Step 4: Determine Ω PD The largest charged area PD in TN i (1≤i≤N PD ), generate PD i The set of disconnectable branches Ω C ={C b |b=1,2,...,N C}. If Ω C If it is an empty set, go to step 9; otherwise, set b=1 and go to step 5.

[0077] Step 5: Simulate disconnection of Ω C The nodes and branches in the electrified area that cannot continue to receive power after the b-th disconnectable branch is disconnected are the sub-electrified area to be transferred corresponding to the b-th disconnectable branch, and the energized load in the sub-electrified area to be transferred is the load to be transferred. Further, a set of candidate power paths Ω that meet the safety constraints such as the electrified area power flow balance constraint, steady-state safety constraint, and topology constraint is generated for the sub-electrified area to be transferred. RT,b ={RT b,k |k=1,2,...,N RT,b} and its corresponding opposite end charged area set Ω OD ={OD k |k=1,2,...,N RT,b}. If Ω RT,b If the set is empty, go to step 7; otherwise, go to step 6. The candidate power-receiving path only considers nodes at the current voltage level or higher; the available capacity of the electrified area at the opposite end of the path should be greater than the current total load of the electrified sub-area to be transferred.

[0078] Step 6: Deducing the scenario after the transfer of the electrified area to be transferred according to each candidate power path, determine the hot and cold switching schemes during the transfer process, and the transfer cost only considers the load power outage loss during the cold switching period. For each post-transfer scenario, update the power supply range of each electrified area of the distribution network system and its load transfer operation demand index. Δ1 The candidate power path and the opposite end charged area that are the smallest and smaller than the preset threshold generate a transfer plan for the sub-charged area to be transferred, where TN Δ1The calculation of is shown in formula (3). If the path is not unique, the power path and the opposite end energized area with the smallest load transfer operation demand index are selected.

[0079]

[0080] Where, When considering load transfer from a certain power path, the increase in the load transfer operation demand index of the opposite end charged area after the load transfer simulation is executed; LO RT is the transfer cost of load transfer from the power acquisition path.

[0081] Depending on whether a power outage will occur during the transfer of the load from the original live area to the opposite live area, the load is divided into hot reversal and cold reversal. During hot reversal, the two live areas are first closed, and then the loop is opened at an appropriate position so that the load is supplied by the opposite live area. There is no power outage during the load transfer, but the closing conditions must be met: the effective value of the steady-state current after closing is not allowed to exceed the maximum allowable current carrying capacity of the feeder, and the transient process of closing does not cause the current protection to operate. Hot reversal is usually only considered when the phase sequence at both ends of the closing point is consistent and they are powered by the same bus or different busbars running in parallel. Cold reversal of load is to first cut off the load and then put it into the opposite live area. Load power outage losses will occur during the transfer process.

[0082] Step 7: Let b = b + 1, if b > N C , go to step 8, otherwise go to step 5.

[0083] Step 8: From PD i Among all the transfer schemes of the sub-charged areas to be transferred, select the one that uses TN Δ2 The largest value greater than the preset threshold is used as PD i If there is a transfer plan for the sub-charged area to be transferred, add it to the transfer plan for the sub-charged area to be transferred and go to step 1. If there is no such plan, go to step 9. Δ2 The calculation of is shown in formula (4).

[0084]

[0085] Where, This is the reduction in the load transfer operation demand index of the local energized area when considering load transfer from a certain power-receiving path.

[0086] Step 9: PD i From Ω PD Remove from the list and go to step 3.

[0087] The purpose of this embodiment is to propose a load transfer optimization method for the effective utilization of distribution network restoration resources based on real-time power outage scenarios. Based on real-time power outage scenarios, it further optimizes the allocation of available power capacity from a global perspective, optimizes the operating mode of the live zone through switching operations, and avoids the impact of unreasonable distribution network topology on global restoration benefits. The present invention adjusts the available power capacity and its distribution by optimizing the load transfer scheme. Depending on whether a load outage occurs during the load transfer operation, it can be divided into hot load switching and cold load switching. In hot switching, two live zones are first paralleled, and then the loop is opened at an appropriate location to transfer the load from the original live zone to another live zone or other branches of the same live zone. During this period, the load is not shut down. The paralleling of distribution network live zones powered by different TBs in the same transmission network segment is a closed loop operation. In cold switching, the load is first removed and then switched to the opposite live zone. The load outage loss generated during the operation is calculated based on the load's unit outage loss and the load's power supply interruption amount. The evaluation duration is the total time taken for all load switching operations in the distribution network.

[0088] Example 2

[0089] This embodiment provides a load transfer decision-making device for global optimal configuration of distribution network restoration resources, including:

[0090] The demand index calculation module is used to determine the power supply range of each electrified area and calculate the load transfer operation demand index TN of each electrified area;

[0091] Add a module to set TN to be greater than the preset threshold TN J (TN J >0) are added to the charged area set Ω for which the decision on the live load transfer is to be made. PD ={PD i |i=1,2,...,N PD}, where PD i is the i-th charged region, N PD is Ω PD Total number of medium charged areas;

[0092] The process end module is used to judge Ω PD If the set is empty, the process ends; otherwise, it goes to the disconnectable branch set generation module;

[0093] The disconnectable branch set generation module is used to determine Ω PD The largest charged area PD in TN i (1≤i≤N PD ), generate PD i The set of disconnectable branches Ω C ={C b |b=1,2,...,N C}, Cb is Ω C The bth branch can be disconnected, N C Is the total number of disconnectable branches; if Ω C Is an empty set, corresponding to PD i From Ω PD If it is eliminated, go to the process end module, otherwise set b=1 and go to the simulation module;

[0094] Simulation module, used to simulate disconnection of Ω C The bth disconnectable branch in the network generates a set of candidate power paths that meet the safety constraints for the sub-energized area to be transferred corresponding to the bth disconnectable branch. RT,b ={RT b,k |k=1,2,...,N RT,b} and its corresponding opposite end charged area set Ω OD ={OD k |k=1,2,...,N RT,b}, where RT b,k is Ω RT,b The kth candidate power path in N RT,b is Ω RT,b The total number of candidate power paths in OD k is Ω OD The kth opposite end charged area, OD k Is with Ω RT,b The kth candidate power path RT in b,k The only corresponding opposite end charged area, if Ω RT,b If it is an empty set, it will go to the judgment module, otherwise it will go to the transfer plan generation module;

[0095] The transfer scheme generation module is used to deduce the scenarios after the transfer of the electrified sub-area to be transferred according to each candidate power acquisition path, determine the hot and cold transfer schemes during the transfer process, and update the power supply range of each electrified area of the distribution network system and its load transfer operation demand index for each post-transfer scenario; select the TN Δ1 The candidate power acquisition path and the opposite end powered area that are the smallest and smaller than the preset threshold are used to generate a transfer plan for the sub-powered area to be transferred;

[0096] Judgment module, used to set b=b+1, if b>N C , then go to step 8, otherwise go to the simulation module;

[0097] Transfer plan selection module, used to select i Among all the transfer schemes of the sub-charged areas to be transferred, select the one that uses TN Δ2 The largest value greater than the preset threshold is used as PD iIf there is such a plan, add it to the transfer plan of the sub-charged area to be transferred and transfer it to the demand index calculation module. If it does not exist, add PD i From Ω PD Remove it and go to the process end module.

[0098] Specifically, in the demand index calculation module, the calculation formula of the load transfer operation demand index TN is as follows:

[0099]

[0100] Where, γ Lj is the unit power outage loss of the load to be restored at load node j, is the capacity of the load to be restored at load node j, is the available power that load node j can obtain from the energized area of the distribution network is the power available to load node j; N J is the total number of load nodes to be restored within the power supply range of the electrified area, and j is the sequence number of the load nodes to be restored within the power supply range of the electrified area.

[0101] Specifically, in the demand index calculation module, the γ Lj The value of is the maximum value of the load unit power outage loss within the range from the restoration decision moment to the evaluation end moment.

[0102] Specifically, in the demand index calculation module, the The value of is the maximum value of the load restoration demand within the range from the restoration decision moment to the evaluation end moment.

[0103] Specifically, in the demand index calculation module, the N J This includes power-off load nodes and energized load nodes that still require load restoration.

[0104] Specifically, in the demand index calculation module, the available power that the load node j can obtain from the electrified area of the distribution network is The load nodes within the power supply range of the live area need to be sorted in descending order according to the unit power outage loss of the load to be restored, and the available power of the live area of the distribution network is allocated to each load node in sequence under the premise of meeting the power flow balance constraint, steady-state safety constraint, and topology constraint of the live area;

[0105] The available power of the live area of the distribution network is the sum of the power supply plan of the transmission network, the spinning reserve capacity of the live area of the distribution network and the capacity of the units being restored, and is determined by the maximum value within the range from the restoration decision time to the evaluation end time.

[0106] Specifically, in the transfer plan generation module, TN Δ1 The calculation formula is as follows:

[0107]

[0108] Where, LO is the increase in the load transfer operation demand index of the opposite end energized area after the load transfer simulation is executed when considering load transfer from any power path; RT is the transfer cost of load transfer from the power acquisition path.

[0109] Specifically, in the transfer plan generation module, if the path is not unique, the power-obtaining path and the opposite-end energized area with the smallest load transfer operation demand index are selected.

[0110] Specifically, in the transfer scheme generation module, the hot switching and cold switching schemes are divided according to whether a power outage will occur during the transfer of the load from the original live area to the opposite live area; during hot switching, the two live areas are first closed, and then the loop is opened at an appropriate position so that the load is supplied by the opposite live area. There is no power outage during the load transfer process, but the closing conditions must be met: the effective value of the steady-state current after closing is not allowed to exceed the maximum allowable current carrying capacity of the feeder, and the transient process of closing does not cause the current protection to operate; hot switching is only selected when the phase sequence at both ends of the closing point is consistent and they are powered by the same bus or different bus power supplies running in parallel. The load cold switching is to first cut off the load and then put it into the opposite live area. The load power outage loss generated during the operation is calculated according to the unit power outage loss of the load and the load power supply stoppage power supply by the following formula:

[0111]

[0112] Where t0 is the time when the load starts to recover, t e is the preset evaluation end time; γ(t), ΔP L (t) are the unit power outage loss and active capacity of the restored load at time t, respectively.

[0113] Specifically, in the transfer scheme selection module, TN Δ2 The calculation formula is as follows:

[0114]

[0115] Where, This is the reduction in the load transfer operation demand index of the local energized area when considering load transfer from any power-obtaining path.

[0116] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiment of the present application can be implemented in various computer languages, for example, object-oriented programming language Java and literal translation scripting language JavaScript, etc.

[0117] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0118] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0119] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0120] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0121] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A load transfer decision method for global optimal configuration of distribution network restoration resources, characterized in that: include: Step 1: Determine the power supply range of each electrified area and calculate the load transfer operation demand index of each electrified area , the calculation formula is as follows: （1）； Where, is the unit power outage loss of the load to be restored at load node j, is the capacity of the load to be restored at load node j, is the available power that load node j can obtain from the energized area of the distribution network , is the power available to load node j; is the total number of load nodes to be restored within the power supply range of the electrified area, and j is the sequence number of the load node to be restored within the power supply range of the electrified area; Step 2: Greater than the preset threshold The electrified area is added to the electrified area set for which the electrified load transfer decision is to be made. ,in, is the i-th charged region, yes Total number of medium charged areas; >0; Step 3: If If it is an empty set, end this process, otherwise go to step 4; Step 4: Determine middle The largest charged area , ,generate The set of disconnectable branches , yes Article b can disconnect the branch line. Is the total number of disconnectable branches; if is an empty set, corresponding to from Remove it and go to step 3, otherwise set b=1 and go to step 5; Step 5: Simulate a disconnect For the bth disconnectable branch, a set of candidate power paths that meet the safety constraints is generated for the sub-energized area to be transferred corresponding to the bth disconnectable branch. and its corresponding opposite end charged area set ,in, yes The kth candidate power path in yes The total number of candidate power paths, yes The kth opposite end charged area, is with The kth candidate power path in The only corresponding opposite end charged area, if If it is an empty set, go to step 7, otherwise go to step 6; Step 6: Deducing the scenarios after the transfer of the electrified sub-areas to be transferred according to each candidate power acquisition path, determining the hot and cold switching schemes during the transfer process, and updating the power supply range of each electrified area of the distribution network system and its load transfer operation demand index for each post-transfer scenario; selecting The candidate power acquisition path and the opposite end powered area that are the smallest and smaller than the preset threshold are used to generate a transfer plan for the sub-powered area to be transferred; Step 7: Let b=b+1, if b> , then go to step 8, otherwise go to step 5; Step 8: From Select the transfer scheme of all the sub-charged areas to be transferred. The largest one that is greater than the preset threshold is used as If there is such a plan, add it to the transfer plan of the sub-charged area to be transferred and go to step 1. If there is no such plan, add from Remove from the list and go to step 3.

2. The load transfer decision method for global optimal configuration of distribution network restoration resources according to claim 1 is characterized in that: described The value of is the maximum value of the load unit power outage loss within the range from the restoration decision moment to the evaluation end moment.

3. The load transfer decision method for global optimal configuration of distribution network restoration resources according to claim 1 is characterized in that: described The value of is the maximum value of the load restoration demand within the range from the restoration decision moment to the evaluation end moment.

4. The load transfer decision method for global optimal configuration of distribution network restoration resources according to claim 1 is characterized in that: described This includes power-off load nodes and energized load nodes that still require load restoration.

5. The load transfer decision method for global optimal configuration of distribution network restoration resources according to claim 1 is characterized in that: The available power that the load node j can obtain from the electrified area of the distribution network , it is necessary to sort the load nodes within the power supply range of the live area in descending order according to the unit power outage loss of the load to be restored, and allocate the available power of the live area of the distribution network to each load node in sequence under the premise of meeting the power flow balance constraint, steady-state safety constraint, and topology constraint of the live area; The available power of the live area of the distribution network is the sum of the power supply plan of the transmission network, the spinning reserve capacity of the live area of the distribution network and the capacity of the units being restored, and is determined by the maximum value within the range from the restoration decision time to the evaluation end time.

6. The load transfer decision method for global optimal configuration of distribution network restoration resources according to claim 1 is characterized in that: In step 6, The calculation formula is as follows: （2）； Where, Considering load transfer from any power path, the increase in the load transfer operation demand index of the opposite end energized area after the load transfer simulation is executed; is the transfer cost of load transfer from the power acquisition path.

7. The load transfer decision method for global optimal configuration of distribution network restoration resources according to claim 1 is characterized in that: In step 6, if the path is not unique, the power-obtaining path and the opposite-end energized area with the smallest load transfer operation demand index are selected.

8. The load transfer decision method for global optimal configuration of distribution network restoration resources according to claim 1 is characterized in that: In step 6, the hot and cold switching schemes are divided according to whether a power outage will occur during the transfer of the load from the original energized area to the opposite end energized area; During hot switching, the two live zones are first closed, and then the loop is opened at an appropriate position so that the load is supplied by the live zone at the opposite end. There is no power outage during the load transfer process, but the closing conditions must be met: the effective value of the steady-state current after closing must not exceed the maximum allowable current carrying capacity of the feeder, and the transient process of closing does not cause the current protection to operate. Hot switching is only selected when the phase sequence at both ends of the closing point is consistent and they are supplied by the same bus or different busbars running in parallel. Cold switching of loads involves first removing the load and then supplying it to the live zone at the opposite end. The load power outage loss generated during the operation is calculated based on the load's unit power outage loss and the load's power supply interruption using the following formula: （3）； Where, is the moment when the load starts to recover, The preset end time of the assessment; 、 are the unit power outage loss and active capacity of the restored load at time t respectively.

9. The load transfer decision method for global optimal configuration of distribution network restoration resources according to claim 1, characterized in that: In step 8, The calculation formula is as follows: （4）； Where, This is the reduction in the load transfer operation demand index of the local energized area when considering load transfer from any power-obtaining path.

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