Methods, devices and distribution network for fault recovery

Abstract

This invention relates to a method, apparatus, and distribution network for fault recovery in a power grid, belonging to the field of power. The method includes: constructing a distribution network topology based on distribution network parameters; forming preliminary partitions of distributed power sources on each feeder of the distribution network based on the distribution network topology: dividing the distribution network into passive and active zones; further partitioning the passive and active zones using an optimization algorithm based on the overall loss objective function and constraints, resulting in partitions dependent on external power transfer, autonomous microgrids, partitions supported by distributed power sources within the zone plus synchronous power sources outside the zone, and partial load shedding partitions; and implementing different fault recovery strategies according to different partitions. This invention can restore power supply during a fault.

Description

Technical Field

[0001] This invention relates to the field of power, and in particular to a method, apparatus and distribution network for fault recovery in power distribution networks. Background Technology

[0002] With the development of the social economy and the transformation of the energy structure, the power distribution network, as the "last mile" connecting the transmission and distribution network and end users, is receiving increasing attention for its power supply reliability and intelligence level.

[0003] With the large-scale integration of distributed energy resources, the structure and operating characteristics of medium- and low-voltage distribution networks have undergone profound changes. On the one hand, these new resources provide greater flexibility and possibilities for distribution network operation optimization and fault recovery; on the other hand, they also significantly increase the complexity and uncertainty of distribution networks, posing a severe challenge to traditional fault handling models.

[0004] Existing self-healing control strategies for distribution network faults have low adjustment capabilities and struggle to achieve multi-objective optimization, resulting in recovery schemes requiring extensive manual intervention and exhibiting low recovery efficiency. Summary of the Invention

[0005] To solve the above-mentioned technical problems, or at least partially solve them, the present invention provides a method, apparatus and distribution network for power distribution network fault recovery.

[0006] In a first aspect, the present invention provides a method for restoring faults in a power distribution network, the method comprising:

[0007] Based on the distribution network parameters, construct the distribution network topology;

[0008] Based on the distribution network topology, the distributed power sources on each feeder of the distribution network are initially partitioned: the distribution network is divided into passive area and active area;

[0009] Based on the overall loss objective function and constraints, an optimization algorithm is used to perform a secondary division of the passive and active regions, which are divided into externally dependent power supply zones, autonomous microgrid zones, zones supported by distributed power sources within the zone and synchronous power sources outside the zone, and zones with partial load shedding.

[0010] Different fault recovery strategies are implemented for different partitions;

[0011] Wherein, the passive zone is a region excluding distributed power nodes, the autonomous microgrid partition is a region whose internal power supply capacity is greater than or equal to the internal load demand, the partition supported by distributed power sources within the zone and synchronous power sources outside the zone is a region whose internal power supply capacity is less than the internal load demand, and the load of this partition is a first-class load or a second-class load; the partial load shedding partition is a region whose internal power supply capacity is less than the internal load demand, and the load of this partition is a third-class load.

[0012] Optionally, the overall loss objective function for:

[0013] ;

[0014] ;

[0015] ;

[0016] ;

[0017] in, , , These are the weighting coefficients. ; Let be the power loss function. Let the power outage loss function be... This is the load loss function; It is a collection of distributed power sources. For the first The cost factor of this type of distributed power source As a sign of being offline, x i For the first Types of distributed power source disconnection penalty factors, For the first Maximum output of this type of distributed power source; Represents the load set. For load The weighting coefficients, For load The duration of the power outage, For load The power; For partitioned sets, Indicates partition Fault recovery success rate factor For partitioning Reduce the load.

[0018] Optionally, the constraints include: hierarchical topology constraints, recovery path feasibility constraints, power balance constraints, node voltage constraints, transmission power constraints, energy storage continuity constraints, charge and discharge power mutual exclusion constraints, distributed power output constraints, and system frequency constraints.

[0019] Optionally, the step of implementing different fault recovery strategies based on different partitions includes:

[0020] If the partition that failed is a partition that relies on an external data transfer service, then:

[0021] The faulty, externally dependent sub-district can obtain power from outside the faulty sub-district via a tie switch.

[0022] Optionally, the step of implementing different fault recovery strategies based on different partitions includes:

[0023] If the partition that experienced the failure is the autonomous micronet partition, then:

[0024] The internal power transfer of the autonomous microgrid partition that has failed is completed through the interconnection switch.

[0025] Optionally, the step of implementing different fault recovery strategies based on different partitions includes:

[0026] If the partition where the fault occurs is supported by both distributed power sources within the partition and synchronous power sources outside the partition, then:

[0027] The faulty distributed power source within the zone and the synchronous power source outside the zone support the zone through the interconnection switch, so that both internal and external power transfer can be realized at the same time.

[0028] Optionally, the step of implementing different fault recovery strategies based on different partitions includes:

[0029] If the partition where the failure occurred is a partially load-cutting partition, then:

[0030] The types of load nodes within the partially load shelving zone where a fault has occurred are identified. These load node types include Class I loads, Class II loads, and Class III loads. The power supply nodes within the partially load shelving zone where a fault has occurred are restored to full power supply to Class I and Class II loads, while power supply to Class III loads is stopped. Herein, Class I loads are critical loads, Class II loads are secondary critical loads, and Class III loads are ordinary loads.

[0031] Secondly, the present invention provides a power distribution network fault recovery device, the device comprising:

[0032] The parameter acquisition unit is used to construct the distribution network topology based on the distribution network parameters;

[0033] A partitioning unit is used to initially partition the distributed power sources on each feeder of the distribution network according to the distribution network topology: dividing the distribution network into passive and active zones.

[0034] The partitioning unit is also used to perform secondary partitioning of the passive area and active area based on the overall loss objective function and constraints, using an optimization algorithm to divide them into external power supply dependent partitioning, autonomous microgrid partitioning, partitioning supported by distributed power sources within the area and synchronous power sources outside the area, and partial load shedding partitioning.

[0035] The recovery unit is used to execute different fault recovery strategies based on different partitions;

[0036] Wherein, the passive zone is a region excluding distributed power nodes, the autonomous microgrid partition is a region whose internal power supply capacity is greater than or equal to the internal load demand, the partition supported by distributed power sources within the zone and synchronous power sources outside the zone is a region whose internal power supply capacity is less than the internal load demand, and the load of this partition is a first-class load or a second-class load; the partial load shedding partition is a region whose internal power supply capacity is less than the internal load demand, and the load of this partition is a third-class load.

[0037] Thirdly, the present invention provides a power distribution network that applies the method described in any of the preceding claims.

[0038] The beneficial effects of this invention are as follows: This invention divides the distribution network twice. First, it divides the network into passive and active zones. Then, it uses an optimization algorithm to further divide the passive and active zones into zones dependent on external power transfer, autonomous microgrid zones, zones supported by distributed power sources within the zone and synchronous power sources outside the zone, and zones with partial load shedding. Furthermore, different fault recovery strategies are implemented according to different zones. By dividing the distribution network into more refined segments and implementing different fault recovery strategies, the invention can maximize the restoration of power supply through fault self-healing zone reconstruction while satisfying multi-objective optimization. This can solve the complex fault recovery and control problems brought about by the widespread access of distributed resources to multi-voltage level distribution network systems. Attached Figure Description

[0039] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 The diagram shown is a flowchart of the power distribution network fault recovery method according to an embodiment of the present invention.

[0042] Figure 2 The diagram illustrates an application scenario of the power distribution network fault recovery method according to an embodiment of the present invention. Figure 1 ;

[0043] Figure 3 The diagram illustrates an application scenario of the power distribution network fault recovery method according to an embodiment of the present invention. Figure 2 ;

[0044] Figure 4 The diagram illustrates an application scenario of the power distribution network fault recovery method according to an embodiment of the present invention. Figure 3 ;

[0045] Figure 5 The diagram shown is a structural block diagram of a power distribution network fault recovery device according to an embodiment of the present invention. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] Figure 1 The diagram shows a flowchart of a power distribution network fault recovery method according to an embodiment of the present invention. The method includes:

[0048] Step 110: Construct the distribution network topology based on the distribution network parameters; the distribution network parameters include power supply information, load information, and switch information.

[0049] Step 120: Based on the distribution network topology, form a preliminary partition of the distributed power sources on each feeder of the distribution network: divide the distribution network into passive area and active area; specifically: if there are no distributed power sources, it is a passive area; if there are distributed power sources, it is marked as an active area.

[0050] Step 130: Based on the overall loss objective function and constraints, an optimization algorithm is used to perform a secondary division of the passive and active regions, resulting in partitions that rely on external power transfer, autonomous microgrids, distributed power sources within the region plus synchronous power sources outside the region, and partial load shedding. For example, the optimization algorithm is a reinforcement learning algorithm.

[0051] Step 140: Implement different fault recovery strategies based on different partitions;

[0052] Wherein, the passive zone is a region excluding distributed power nodes; the autonomous microgrid partition is a region whose internal power supply capacity is greater than or equal to its internal load demand; the partition supported by distributed power sources within the zone and synchronous power sources outside the zone is a region whose internal power supply capacity is less than its internal load demand, and the load in this partition is a first-class load or a second-class load; the partial load shedding partition is a region whose internal power supply capacity is less than its internal load demand, and the load in this partition is a third-class load; wherein, the first-class load is an important load, the second-class load is a secondary important load, and the third-class load is a normal load.

[0053] In this embodiment of the invention, the distribution network is divided twice. First, a passive zone and an active zone are defined. Then, the active and passive zones are further divided into externally dependent power transfer zones, autonomous microgrid zones, zones supported by distributed power sources within the zone plus external synchronous power sources, and partial load shedding zones. Different fault recovery strategies are implemented for each zone. This embodiment of the invention provides a relatively fine division of the distribution network and implements different fault recovery strategies. It can maximize the restoration of power supply through fault self-healing zone reconstruction while satisfying multi-objective optimization, and can solve the complex fault recovery and control problems brought about by the widespread access of distributed resources to multi-voltage level distribution network systems.

[0054] In this embodiment of the invention, the power supply information includes: the geographical coordinates of the distributed power source, the access voltage level of the distributed power source, the rated capacity of the distributed power source, the real-time available number of distributed power sources, and the primary electrical parameters of the distributed power source; the load information includes: the geographical coordinates of the load, the capacity of the load, the importance level of the load, and the interruptible / transferable identifier of the load; the switch information includes: the number of available communication channels, the rated transmission capacity of the available communication channels, and the real-time on / off status of the available communication channels.

[0055] In this embodiment of the invention, the overall loss objective function for:

[0056] ;

[0057] ;

[0058] ;

[0059] ;

[0060] in, , , These are the weighting coefficients. ; Let be the power loss function. C is a collection of distributed power sources. DG,i For the first The cost factor of this type of distributed power source This is a sign that the network is disconnected. For the first Types of distributed power source disconnection penalty factors, ∈ {0, 1}, representing the grid-connected state of distributed generation (DG) (1: grid-connected, 0: off-grid); For the first Maximum output of the type of distributed power source Represents a load set; For partitioned sets; Let the power outage loss function be... For load The weighting coefficients, For load The duration of the power outage, For load power, Let be the load loss function. ∈ {0, 1} represents a partition. Fault recovery success rate factor For partitioning Reduce the load.

[0061] In this embodiment of the invention, the constraints include: hierarchical topology constraints, recovery path feasibility constraints, power balance constraints, node voltage constraints, transmission power constraints, energy storage continuity constraints, charge and discharge power mutual exclusion constraints, distributed power output constraints, and system frequency constraints.

[0062] These constraints ensure that the parameters of each partition meet various requirements such as actual conditions, upper and lower limits, and maximum carrying capacity, thus guaranteeing the rationality and optimality of the partition and the safety performance of the distribution network.

[0063] The hierarchical constraint topology is configured as follows:

[0064] ;

[0065] ;

[0066] in, For the first One partition, For the first The self-balancing rate threshold for each partition, For the first The output of this type of distributed power source For load power, , This represents the total number of zones in the power distribution network. For the first One partition; For the first One partition; This means that the union of all partitions equals the set of partitions of the entire distribution network; This indicates that there is no overlap between any two distinct partitions;

[0067] The feasibility constraints of the recovery path are as follows:

[0068] ;

[0069] in, ∈{0,1}, Used to indicate switch status For the first The partition to the first The recovery path for each partition;

[0070] The power balance constraint is implemented in the following manner:

[0071] ;

[0072] in, To provide power output within the zone, For the load within the partition, This represents the set of power nodes.

[0073] The node voltage constraint is implemented in the following manner:

[0074] ;

[0075] in, Bus voltage This is the upper limit of the node voltage. This is the lower limit of the node voltage.

[0076] The power transmission constraint is implemented in the following manner:

[0077] ;

[0078] in, This is the actual value of the transmitted power. This is the upper limit of the transmission power. This is the lower limit of the transmission power;

[0079] The energy storage continuity constraint is implemented in the following manner:

[0080] ;

[0081] ;

[0082] in, For energy storage At any given moment, the state of charge To improve the charging efficiency of energy storage systems. For the discharge efficiency of the energy storage system For energy storage Constant charging power, For energy storage Discharge power at all times For time intervals, The rated energy of the energy storage system, This is the lower limit of energy storage capacity. This represents the upper limit of energy storage capacity.

[0083] The mutual exclusion constraint of charging and discharging power is implemented in the following manner:

[0084] ;

[0085] ;

[0086] ;

[0087] in, For energy storage Constant charging power, It is an electrical status indicator and takes the value 0 or 1 (when it is 0, it means that the energy storage system is not performing any operation (neither charging nor discharging); when it is 1, it means that the energy storage system is in a charging or discharging state). For energy storage Discharge power at all times This represents the maximum charging power of the energy storage system. This represents the maximum discharge power of the energy storage system.

[0088] The distributed power output constraint is implemented in the following manner:

[0089] ;

[0090] in, This represents the lower limit of the output power of distributed power sources. For the output of distributed power sources, This represents the upper limit of the output power of the distributed power source.

[0091] The system frequency constraint is implemented in the following manner:

[0092] ;

[0093] in, This is the lower limit of the power system frequency. This represents the actual value of the power system frequency. This represents the upper limit of the power system frequency.

[0094] In this embodiment of the invention, step 140, which involves executing different fault recovery strategies based on different partitions, includes:

[0095] If the faulty partition is a partition that relies on external power supply, then the faulty partition that relies on external power supply will obtain power from outside the faulty partition through the tie switch.

[0096] In this embodiment of the invention, the step of executing different fault recovery strategies according to different partitions includes: if the partition that has failed is the autonomous microgrid partition, then the internal supply transfer of the autonomous microgrid partition that has failed is completed through a handshake switch.

[0097] In this embodiment of the invention, the execution of different fault recovery strategies according to different partitions includes: if the partition where the fault occurs is a partition supported by distributed power supply within the partition and synchronous power supply outside the partition, then the partition supported by distributed power supply within the partition and synchronous power supply outside the partition where the fault occurs is connected to a tie switch to simultaneously realize internal power transfer and external power transfer.

[0098] In this embodiment of the invention, step 140, which involves executing different fault recovery strategies based on different partitions, includes: if the partition where the fault occurred is a partial load shedding partition, then: obtaining the types of load nodes within the partial load shedding partition where the fault occurred, wherein the types of load nodes include first-class loads, second-class loads, and third-class loads; restoring the power supply nodes within the partial load shedding partition where the fault occurred to provide full power to the first-class loads and the second-class loads, and stopping the power supply to the third-class loads; wherein the first-class loads are important loads, the second-class loads are secondary important loads, and the third-class loads are ordinary loads.

[0099] In this embodiment of the invention, the distribution network is divided into more refined sections and different fault recovery strategies are implemented. This can maximize the restoration of power supply through fault self-healing partition reconstruction while satisfying multi-objective optimization. It can solve the complex fault recovery and control problems brought about by the widespread access of distributed resources to multi-voltage level distribution network systems.

[0100] Figure 2 The diagram shown is a schematic representation of an application scenario of the power distribution network fault recovery method according to an embodiment of the present invention. Figure 2 In the illustrated embodiment, there are 8 nodes, which can be divided into three zones using the method of this embodiment of the invention. Figure 2 The layers shown are arranged according to voltage, with each layer having the same voltage.

[0101] In the method of this embodiment of the invention, nodes with different voltages can be assigned to the same partition during partitioning.

[0102] Figure 3 , Figure 4 The diagram shown is a schematic diagram of another application scenario of the power distribution network fault recovery method according to an embodiment of the present invention.

[0103] refer to Figure 3The diagram shows the topology of a 10kV / 35kV distribution network, including: power source, main bus M, main bus N, 110 / 35kV transformer, 110 / 10kV transformer, 10kV bus I, 10kV bus II, 35kV bus I, 35kV bus II, circuit breaker QF1, circuit breaker QF2, feeders 1-5, transformer substation I, and transformer substation II. Indicates a fault. Using the method of this embodiment of the invention, the partitioning results are referenced. Figure 4 express.

[0104] Reference Figure 4 As shown, the self-healing process of each partition is as follows:

[0105] (1) Partition I - Dependent on externally supplied partition.

[0106] After the fault occurs, the reinforcement learning algorithm provides the optimal partitioning scheme: Node 1 and Node 2 complete the power transfer through a tie switch. This partition has no power supply and relies entirely on the external tie line to absorb the power deficit. It can achieve 100% load restoration within seconds without the need for local power supply, achieving the goal of "zero power outage" self-healing.

[0107] (2) Partition II - Autonomous micronet partition, autonomous micronet within the partition.

[0108] With ample capacity for local distributed power generation and energy storage, these resources were isolated and formed into an autonomous microgrid of "source-storage-load". During fault periods, they can provide continuous power without any external support, verifying the "island stability" capability in high-proportion DG scenarios.

[0109] (3) Partition III - Partition supported by distributed power sources within the zone and synchronous power sources outside the zone.

[0110] This area primarily relies on distributed renewable energy sources, but its capacity is slightly lower than the load demand, requiring a small amount of power supplemented by the external grid. It is further subdivided into two complementary power transfer paths:

[0111] Zone III-1: After external transfer of power, there is a local oversupply of new energy sources, and the curtailment of wind and solar power is relatively high.

[0112] Zone III-2: Through flexible interconnection with adjacent transformer areas via tie switches, the utilization rate of renewable energy is significantly improved, the curtailment rate decreases by 60%, and the load recovery rate increases to 98%. Therefore, Zone III-2 can minimize distributed power generation losses and maximize load utilization.

[0113] (4) Zone IV - Partial load shedding zone, partial load shedding for power limiting and stability maintenance.

[0114] Although distributed renewable energy sources can be networked independently, their capacity still cannot meet all load demands. By prioritizing loads, the three types of loads at node 6 are cut off to ensure 100% power supply to the first and second types of loads, while maintaining stable voltage and frequency in the affected areas, achieving a flexible self-healing mechanism that prevents power outages from causing system crashes.

[0115] Figure 5 The diagram shown is a structural block diagram of a power distribution network fault recovery device according to an embodiment of the present invention. Figure 5 As shown, the device includes:

[0116] The parameter acquisition unit 510 is used to construct the distribution network topology based on the distribution network parameters.

[0117] The partitioning unit 520 is used to form a preliminary partition of the distributed power sources on each feeder of the distribution network according to the distribution network topology: the distribution network is divided into a passive area and an active area.

[0118] The partitioning unit 520 is also used to perform secondary partitioning of the passive area and active area based on the overall loss objective function and constraints, using an optimization algorithm, into partitions that rely on external power transfer, autonomous microgrid partitions, partitions supported by distributed power sources within the area and synchronous power sources outside the area, and partitions that partially cut off loads.

[0119] Recovery unit 530 is used to execute different fault recovery strategies based on different partitions.

[0120] Wherein, the passive zone is a region excluding distributed power nodes; the autonomous microgrid partition is a region whose internal power supply capacity is greater than or equal to its internal load demand; the partition supported by distributed power sources within the zone and synchronous power sources outside the zone is a region whose internal power supply capacity is less than its internal load demand, and the load in this partition is a first-class load or a second-class load; the partial load shedding partition is a region whose internal power supply capacity is less than its internal load demand, and the load in this partition is a third-class load; wherein, the first-class load is an important load, the second-class load is a secondary important load, and the third-class load is a normal load.

[0121] In this embodiment of the invention, the recovery unit 530 is further configured to: if the faulty partition is a partition dependent on external power supply, then enable the faulty partition dependent on external power supply to obtain power from outside the faulty partition dependent on external power supply through a handshake switch.

[0122] In this embodiment of the invention, the recovery unit 530 is further configured to: if the partition that has failed is the autonomous microgrid partition, then enable the internal transfer of power within the autonomous microgrid partition that has failed to complete the internal transfer via a handshake switch.

[0123] In this embodiment of the invention, the recovery unit 530 is further configured to: if the faulty partition is a partition supported by distributed power supply within the partition and synchronous power supply outside the partition, then enable the faulty partition supported by distributed power supply within the partition and synchronous power supply outside the partition to simultaneously achieve internal power transfer and external power transfer through the interconnection switch.

[0124] In this embodiment of the invention, the recovery unit 530 is further configured to: if the faulty partition is a partial load shedding partition, then: obtain the types of load nodes within the faulty partial load shedding partition, the types of load nodes including first-class loads, second-class loads and third-class loads; restore the power supply nodes within the faulty partial load shedding partition to provide full power to the first-class loads and the second-class loads, and stop power supply to the third-class loads; wherein, the first-class loads are important loads, the second-class loads are secondary important loads, and the third-class loads are ordinary loads.

[0125] For any parts of the units not described in detail above, please refer to the relevant descriptions in this embodiment.

[0126] This invention also provides a power distribution network that applies the method described above.

[0127] Figure 1 This is a flowchart illustrating a distribution network fault recovery method in one embodiment. It should be understood that, although... Figure 1 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated in this invention, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Furthermore, Figure 1 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0128] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided by this invention can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0129] It should be noted that in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0130] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined in this invention may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be borne the widest scope consistent with the principles and novel features claimed in this invention.

Claims

1. A method for restoring faults in a power distribution network, characterized in that, The method includes: Based on the distribution network parameters, construct the distribution network topology; Based on the distribution network topology, the distributed power sources on each feeder of the distribution network are initially partitioned: the distribution network is divided into passive area and active area; Based on the overall loss objective function and constraints, an optimization algorithm is used to perform a secondary division of the passive and active regions, which are divided into externally dependent power supply zones, autonomous microgrid zones, zones supported by distributed power sources within the zone and synchronous power sources outside the zone, and zones with partial load shedding. Different fault recovery strategies are implemented for different partitions; Wherein, the passive zone is a region excluding distributed power nodes, the autonomous microgrid partition is a region whose internal power supply capacity is greater than or equal to the internal load demand, the partition supported by distributed power sources within the zone and synchronous power sources outside the zone is a region whose internal power supply capacity is less than the internal load demand, and the load of this partition is a first-class load or a second-class load; the partial load shedding partition is a region whose internal power supply capacity is less than the internal load demand, and the load of this partition is a third-class load. The overall loss objective function for: ； ； ； ； in, , , These are the weighting coefficients. ; Let be the power loss function. Let the power outage loss function be... This is the load loss function; It is a collection of distributed power sources. For the first The cost factor of this type of distributed power source This is a sign that the network is disconnected. For the first Types of distributed power source disconnection penalty factors, For the first Maximum output of this type of distributed power source; Represents the load set. For load The weighting coefficients, For load The duration of the power outage, For load The power; For partitioned sets, Indicates partition Fault recovery success rate factor For partitioning Reduce load; The implementation of different fault recovery strategies based on different partitions includes: If the partition where the fault occurs is supported by both distributed power sources within the partition and synchronous power sources outside the partition, then: The faulty distributed power source within the zone and the synchronous power source outside the zone support the zone through the interconnection switch, so that internal power transfer and external power transfer can be realized at the same time. The implementation of different fault recovery strategies based on different partitions includes: If the partition where the failure occurred is a partially load-cutting partition, then: The types of load nodes within the partially load shelving zone where a fault has occurred are identified. These load node types include Class I loads, Class II loads, and Class III loads. The power supply nodes within the partially load shelving zone where a fault has occurred are restored to full power supply to Class I and Class II loads, while power supply to Class III loads is stopped. Herein, Class I loads are critical loads, Class II loads are secondary critical loads, and Class III loads are ordinary loads.

2. The power distribution network fault recovery method according to claim 1, characterized in that, The constraints include: hierarchical topology constraints, recovery path feasibility constraints, power balance constraints, node voltage constraints, transmission power constraints, energy storage continuity constraints, charge and discharge power mutual exclusion constraints, distributed power output constraints, and system frequency constraints.

3. The power distribution network fault recovery method according to claim 1, characterized in that, The implementation of different fault recovery strategies based on different partitions includes: If the partition that failed is a partition that relies on an external data transfer service, then: The faulty, externally dependent sub-district can obtain power from outside the faulty sub-district via a tie switch.

4. The power distribution network fault recovery method according to claim 1, characterized in that, The implementation of different fault recovery strategies based on different partitions includes: If the partition that experienced the failure is the autonomous micronet partition, then: The internal power transfer of the autonomous microgrid partition that has failed is completed through the interconnection switch.

5. A power distribution network fault recovery device, characterized in that, The device includes: The parameter acquisition unit is used to construct the distribution network topology based on the distribution network parameters; A partitioning unit is used to initially partition the distributed power sources on each feeder of the distribution network according to the distribution network topology: dividing the distribution network into passive and active zones. The partitioning unit is also used to perform secondary partitioning of the passive area and active area based on the overall loss objective function and constraints, using an optimization algorithm to divide them into external power supply dependent partitioning, autonomous microgrid partitioning, partitioning supported by distributed power sources within the area and synchronous power sources outside the area, and partial load shedding partitioning. The recovery unit is used to execute different fault recovery strategies based on different partitions; Wherein, the passive zone is a region excluding distributed power nodes, the autonomous microgrid partition is a region whose internal power supply capacity is greater than or equal to the internal load demand, the partition supported by distributed power sources within the zone and synchronous power sources outside the zone is a region whose internal power supply capacity is less than the internal load demand, and the load of this partition is a first-class load or a second-class load; the partial load shedding partition is a region whose internal power supply capacity is less than the internal load demand, and the load of this partition is a third-class load. The overall loss objective function for: ； ； ； ； in, , , These are the weighting coefficients. ; Let be the power loss function. Let the power outage loss function be... This is the load loss function; It is a collection of distributed power sources. For the first The cost factor of this type of distributed power source This is a sign that the network is disconnected. For the first Types of distributed power source disconnection penalty factors, For the first Maximum output of this type of distributed power source; Represents the load set. For load The weighting coefficients, For load The duration of the power outage, For load The power; For partitioned sets, Indicates partition Fault recovery success rate factor For partitioning Reduce load; The implementation of different fault recovery strategies based on different partitions includes: If the partition where the fault occurs is supported by both distributed power sources within the partition and synchronous power sources outside the partition, then: The faulty distributed power source within the zone and the synchronous power source outside the zone support the zone through the interconnection switch, so that internal power transfer and external power transfer can be realized at the same time. The implementation of different fault recovery strategies based on different partitions includes: If the partition where the failure occurred is a partially load-cutting partition, then: The types of load nodes within the partially load shelving zone where a fault has occurred are identified. These load node types include Class I loads, Class II loads, and Class III loads. The power supply nodes within the partially load shelving zone where a fault has occurred are restored to full power supply to Class I and Class II loads, while power supply to Class III loads is stopped. Herein, Class I loads are critical loads, Class II loads are secondary critical loads, and Class III loads are ordinary loads.

6. A power distribution network, characterized in that, Apply the method as described in any one of claims 1 to 4.

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