An optimal multiplier method power flow calculation method, system and medium fusing dynamic topology identification of self-healing and self-switching

Abstract

The application discloses a kind of optimal multiplier method distribution network power flow calculation methods, systems and media of fusion self-healing self-throw dynamic topology identification, real-time acquisition distribution network operating data and self-healing self-throw device state information, by analyzing protection signal table identification remote automation device self-healing and self-throw signal type;According to self-healing self-throw action signal dynamically reconstructs current distribution network topology, constructs the node admittance matrix after switch action;Optimal multiplier method is used to carry out power flow calculation, effectively overcome distribution network data observability low, measurement noise is big and other adverse factors;In iteration process, the state change of self-healing self-throw switch is dynamically monitored, once switch action is automatically updated topology and reinitializes power flow calculation;Output self-healing self-throw action after node voltage, branch power and network loss index.The application can truly simulate the influence of self-healing self-throw device action on distribution network power flow distribution, provides reliable calculation support for distribution network fault recovery and operation analysis.

Description

Technical Field

[0001] This invention relates to the field of power system distribution network automation technology, and in particular to an optimal multiplier method, system, and medium for calculating distribution network power flow that integrates self-healing and automatic switching dynamic topology identification. Background Technology

[0002] Distribution network power flow calculation is a fundamental tool for power system analysis, optimized scheduling, and security assessment. With the advancement of smart distribution network construction, distribution automation systems have widely deployed fault-healing and automatic transfer switch (ATS) devices, enabling rapid power restoration after faults and improving power supply reliability. These ATS devices operate locally according to pre-set logic, requiring no remote intervention from the dispatch center, and their actions cause rapid changes in the distribution network topology. To assess the system state after ATS actions, power flow calculation is needed to simulate the actual power flow distribution. However, the topological abrupt changes caused by ATS actions pose significant challenges to traditional power flow calculations: on the one hand, traditional methods typically assume a fixed network topology, making it difficult to adapt to real-time changes in switch states; on the other hand, the sparse distribution network measurement points, low data observability, and poor data quality (such as noise, missing data, and asynchrony) make traditional methods like the Newton-Raphson method prone to divergence when initial values ​​are poor. While existing technologies include dynamic power flow calculation methods that consider topology changes, most employ periodic scanning to update the topology, resulting in insufficient real-time performance and a lack of effective means to address data quality issues. Summary of the Invention

[0003] Purpose of the invention: The present invention aims to provide an optimal multiplier method for distribution network power flow calculation that integrates dynamic topology identification of self-healing and self-switching actions to achieve accurate simulation of the actual power flow distribution after self-healing and self-switching actions and overcomes the convergence difficulties caused by poor distribution network data quality; Another purpose of the present invention is to provide an optimal multiplier method distribution network power flow calculation system and medium that integrates dynamic topology identification of self-healing and self-switching actions.

[0004] Technical solution: The optimal multiplier method for distribution network power flow calculation based on self-healing and self-switching dynamic topology identification, as described in this invention, includes...

[0005] Real-time acquisition of distribution network operation data and status information of self-healing and automatic transfer devices; identification of self-healing and automatic transfer signal types of remote automation devices by parsing protection signal tables; construction of the correlation mapping relationship between signals and the primary distribution model in the system; used for subsequent signal analysis, correction of grid status, and automatic update of grid power flow.

[0006] Based on the self-healing and automatic transfer action signal, the current distribution network topology is dynamically identified, and the node admittance matrix after the switch action is constructed.

[0007] Based on the traditional power flow calculation method, the Newton-Raphson method, an improved power flow calculation method, the optimal multiplier method, is introduced for distribution network power flow calculation. This method is beneficial for power flow convergence in distribution networks and avoids the problem of non-convergence in power flow calculation caused by over-correction.

[0008] During the power flow iteration process, the state changes of the self-healing and self-transfer switch are dynamically monitored. When a switch action is detected, the network topology is automatically updated and the power flow calculation is reinitialized.

[0009] The power flow calculation results are used to evaluate the operating status of the distribution network after the self-healing and automatic switching action, and output node voltage, branch power and network loss indicators.

[0010] Furthermore, the current distribution network topology is dynamically identified based on the self-healing and automatic transfer action signal, as detailed below:

[0011] Request a self-healing and self-transfer policy from the topology service, and identify the set of self-healing and self-transfer switches that are currently in the activated state based on the returned self-healing and self-transfer policy.

[0012] The self-healing and automatic transfer strategy includes equipment identification, execution success indicator, failure reason, original power supply information, fault equipment isolation scheme, local power supply range, line self-healing strategy transfer path and switch station automatic transfer strategy;

[0013] The line self-healing (automatic closing of the tie switch to restore power after the entire distribution network loses power) strategy transfer path includes operating switches, loop fault isolation switches, transfer power information, power supply backbone equipment set and transfer backbone equipment set;

[0014] The automatic transfer switch (automatic closing of the backup automatic transfer switch to restore power supply after a power failure in the switch station) strategy includes switch station identification, automatic transfer switch, power supply information on the opposite side, main switches entering and leaving the switch station, main switches of the switch station, and branch strategies.

[0015] Furthermore, the method for identifying the state of the self-healing automatic transfer switch is as follows:

[0016] Line self-healing activation judgment: Traverse the power supply backbone equipment set and the transfer backbone equipment set in the power supply path. For each distribution network bus equipment, check whether the equipment exists in the protection device to signal type mapping and whether the signal type is a line self-healing signal. If it exists, further query the line self-healing signal mapping to obtain the measurement point. Obtain the signal value from the measurement point to the signal value mapping. If the signal value is one, the self-healing function of the distribution network bus is activated. If the signal value is not one, the line self-healing function is deactivated, and the power supply will not be automatically restored through the tie switch after the line loses power. If the equipment does not exist in the protection device to signal type mapping or the signal type is not a line self-healing signal, the self-healing function of the distribution network substation is deactivated by default. If the self-healing of all substation busbars is activated, the line self-healing strategy can be executed.

[0017] Automatic transfer switch activation judgment: Iterate through the automatic transfer strategies of each substation. For each automatic transfer switch, check if the switch exists in the mapping from protection device to signal type and if the signal type is automatic transfer signal. If it exists, further query the automatic transfer signal mapping to obtain the measurement point. Obtain the signal value from the mapping from the measurement point to the signal value. If the signal value is one, the automatic transfer function of the substation is activated. If the signal value is not one, the automatic transfer function of the substation is deactivated. After power failure, the backup automatic transfer switch will not be automatically closed to restore power supply. If the switch does not exist in the mapping from protection device to signal type or the signal type is not automatic transfer signal, the automatic transfer function of the distribution network substation is deactivated by default. At the same time, check if the bus associated with the switch exists in the bus-level automatic transfer signal mapping. If it exists, the automatic transfer of the substation is blocked by the bus configuration. If it does not exist, the operation logic of the switch is not affected by other bus configurations.

[0018] Substation self-healing and automatic transfer judgment: Traverse the branch strategy of the switch station. For the self-healing switch of the substation, check whether the switch exists in the mapping of protection devices to signal types and whether the signal type is a switch self-healing signal. If it exists, check the line self-healing signal mapping to obtain the measurement point. Obtain the signal value from the mapping of the measurement point to the signal value. If the signal value is one, the substation self-healing function is activated. If the signal value is not one, the substation self-healing function is deactivated. When the substation loses power, the substation tie switch will not be closed to restore power supply. If the switch does not exist in the mapping of protection devices to signal types or the signal type is not a switch self-healing signal, the self-healing function logic is blocked.

[0019] Furthermore, based on the self-healing and automatic transfer action signal, the current distribution network topology is dynamically identified, and the node admittance matrix after the switch action is constructed, as follows:

[0020] Based on the identified self-healing or automatic transfer switch signals, the actual switch self-healing or automatic transfer logic action strategy can be simulated and the switch action sequence can be determined in all power transfer strategies according to the priority of the line, switch station, and distribution room, as well as the start or stop status of the self-healing and automatic transfer signals.

[0021] The network topology is updated based on the switching action results, and the node admittance matrix is ​​recalculated. The formula for calculating the node admittance matrix is ​​as follows:

[0022] ;

[0023] ;

[0024] in, For nodes Self-guided absorbance, For nodes With nodes Mutual admittance between them , For nodes With nodes Branch admittance between For nodes Admittance of the ground branch.

[0025] Furthermore, based on the traditional power flow calculation method, the Newton-Raphson method, an improved power flow calculation method, the optimal multiplier method, is introduced for distribution network power flow calculation. This method is beneficial for power flow convergence in distribution networks and avoids the problem of non-convergence in power flow calculation caused by over-correction. The details are as follows:

[0026] Establish the power balance equations in rectangular coordinate form for power flow calculation in distribution networks:

[0027] ;

[0028] ;

[0029] in, For nodes active power, For nodes reactive power, and Representing nodes respectively The real and imaginary parts of voltage, and Let represent the real and imaginary parts of the nodal admittance matrix, respectively;

[0030] Construct the modified equations for the Newton-Raphson method:

[0031] ;

[0032] in, Let J be the nodal unbalanced power vector, and J be the Jacobian matrix. This is the voltage correction amount;

[0033] Introducing the optimal multiplier The state variable correction is expressed as

[0034] ;

[0035] ;

[0036] in, and These represent the corrected nodes. The real and imaginary parts of voltage;

[0037] The optimal multiplier is found by minimizing the objective function. The objective function for

[0038] .

[0039] Furthermore, the optimal multiplier The solution process is as follows:

[0040] Objective function Expanded into a cubic polynomial:

[0041] ;

[0042] ;

[0043] ;

[0044] ;

[0045] ;

[0046] in, , , and For parameters;

[0047] For the objective function Differentiate and set it to zero:

[0048]

[0049] Obtain the optimal multiplier Candidate values:

[0050]

[0051] Choose the objective function The smallest positive real solution is taken as the optimal multiplier.

[0052] Furthermore, during the power flow iteration process, the state changes of the self-healing and self-transfer switch are dynamically monitored. When a switch action is detected, the network topology is automatically updated and the power flow calculation is reinitialized, as follows:

[0053] Set the power flow calculation time step, and read the distribution network protection signal table through the real-time database interface in each calculation cycle; use the differential comparison method to detect the switch state change: calculate the difference between the current cycle signal value and the previous cycle signal value;

[0054] If the absolute value of the difference is greater than zero, it is determined that the switch state has changed, triggering the topology update flag;

[0055] When the topology update flag is set, the current power flow iteration is stopped, the self-healing and self-reintroduction strategy is requested again from the topology service, and the power flow calculation is initialized in a hot-start manner.

[0056] Furthermore, the state changes of the self-healing and self-transfer switch are dynamically monitored during the power flow iteration process, as detailed below:

[0057] Calculate the voltage amplitude at each node. and phase angle :

[0058]

[0059]

[0060] Check if the node voltage exceeds the limit. The criterion for exceeding the voltage limit is:

[0061]

[0062] Calculate the power distribution of each branch :

[0063]

[0064] Computational system network loss:

[0065]

[0066]

[0067] in, The minimum voltage amplitude at the i-th node. The maximum voltage amplitude at the i-th node. Let be the conjugate of the branch current phasor flowing from node i to node j. Let be the conjugate of the voltage difference between node i and node j. Let i be the conjugate of the mutual admittance between nodes i and j. Indicates taking the real part, This indicates taking the imaginary part. For the system's active power loss, This refers to the system's reactive power loss.

[0068] The optimal multiplier method distribution network power flow calculation system integrating self-healing and self-switching dynamic topology identification described in this invention includes:

[0069] The data acquisition module is used to collect real-time distribution network operation data and self-healing and automatic transfer device status information. By parsing the protection signal table, it identifies the self-healing and automatic transfer signal types of the remote automation device, and constructs the correlation mapping relationship between the signal and the primary distribution model in the system. This is used for subsequent signal parsing, correction of the power grid status, and automatic update of the power grid flow.

[0070] The topology identification module is used to dynamically identify the current distribution network topology based on the self-healing and automatic transfer action signal, and to construct the node admittance matrix after the switch action.

[0071] The power flow calculation module, based on the traditional power flow calculation method Newton-Raphson method, introduces an improved power flow calculation method, the optimal multiplier method, for distribution network power flow calculation;

[0072] The dynamic monitoring module is used to dynamically monitor the state changes of self-healing and self-transfer switches during power flow iteration. When a switch action is detected, the network topology is automatically updated and the power flow calculation is reinitialized.

[0073] The status assessment module is used to assess the operating status of the distribution network after self-healing and automatic switching actions based on the power flow calculation results, and outputs node voltage, branch power and network loss indicators.

[0074] The computer-readable storage medium of the present invention stores a computer program thereon, which, when executed by a processor, implements the steps of the above-described method.

[0075] Beneficial Effects: Compared with the prior art, the significant advantages of this invention are: 1. This invention identifies the current distribution network topology based on the self-healing and automatic transfer operation signal, sends a request to the topology service to obtain the self-healing and automatic transfer strategy, and determines the set of self-healing and automatic transfer switches currently in operation, thereby truly reflecting the local operation results of the self-healing and automatic transfer device; 2. This invention updates the network topology connection relationship based on the switch operation results and recalculates the node admittance matrix, where the self-admittance is the sum of the admittances of all branches connected to the node plus the admittance of the branch to ground, and the mutual admittance is the negative value of the admittance of the branches connecting two nodes; 3. This invention employs the optimal multiplier method for power flow calculation in distribution networks, significantly improving the convergence of power flow calculations in distribution networks with low data observability and high measurement noise, thus ensuring the reliability of simulation calculations. Furthermore, this invention dynamically identifies the local actions of self-healing and automatic transfer devices by real-time monitoring of distribution network protection signal tables, accurately reconstructing the network topology after the actions, and simulating the actual power flow distribution. It establishes a dynamic monitoring and hot-start mechanism to track multiple actions of self-healing and automatic transfer devices in real time, simulating power flow evolution under continuous events. This provides a reliable calculation basis for verifying distribution network self-healing strategies and arranging operation modes. Attached Figure Description

[0076] Figure 1 This is a flowchart of the optimal multiplier method for power flow calculation in distribution networks, which integrates self-healing and self-switching dynamic topology identification, according to the present invention.

[0077] Figure 2 This is a flowchart of the self-healing and self-transfer switch state recognition and topology update process of the present invention;

[0078] Figure 3 This is a flowchart of the iterative process for calculating the optimal multiplier method of the present invention.

[0079] Figure 4 This is a schematic diagram illustrating the calculation of the node admittance matrix in this invention. Detailed Implementation

[0080] The optimal multiplier method for distribution network power flow calculation based on self-healing and self-starting dynamic topology identification described in this invention includes:

[0081] Step 1: Data Acquisition and Status Information Collection. This system establishes communication with distribution automation systems, Supervisory Control and Data Acquisition (SCADA) systems, and Distribution Terminal Units (DTUs) through a real-time database interface to acquire real-time distribution network operation data (such as node voltage, branch current, switch status, etc.) and status information of self-healing and automatic transfer devices. The status information of the self-healing and automatic transfer devices is mainly obtained by accessing the distribution network protection signal table. The distribution network protection signal table includes fields such as: device identifier, protection device identifier, signal type, and signal value. The signal type field is parsed to identify three types of self-healing and automatic transfer signals: signal type is line self-healing signal (corresponding to distribution network bus-level self-healing function), signal type is switch self-transfer signal (corresponding to distribution network circuit breaker-level self-transfer function), and signal type is switch self-healing signal (corresponding to switch-level self-healing function). The distribution network protection signal table records are traversed to establish the following mapping relationships: mapping from protection devices to signal types (recording the signal type corresponding to each protection device), mapping from measurement points to signal values ​​(recording the real-time signal value corresponding to each measurement point), mapping of line self-healing signals (recording the correspondence between protection devices and measurement points for line self-healing signals), mapping of switch automatic transfer signals (recording the correspondence between protection devices and measurement points for switch automatic transfer signals), mapping of bus-level self-healing signals (recording the correspondence between protection devices and measurement points for bus-level self-healing signals), and mapping of bus-level automatic transfer signals (recording the correspondence between protection devices and measurement points for bus-level automatic transfer signals). These mapping relationships provide the foundation for subsequent topology identification.

[0082] Step Two: Self-Healing and Automatic Transfer Signal Identification and Topology Determination. Based on the mapping relationship obtained in Step One, a self-healing and automatic transfer strategy is requested from the topology service. Specifically, the request is sent through the service bus, with the service port being the distribution network application service port, and the service code being "obtain self-healing and automatic transfer strategy through feeder". The request information includes a request identifier and a list of device identifiers. The returned information includes device identifiers, execution success flags, failure reasons, original power supply information, fault equipment isolation scheme, local power supply range, line self-healing strategy transfer path, and switch station automatic transfer strategy. The transfer path includes operating switches (tethering switches), loop fault isolation switches, transfer power supply information, power supply backbone path equipment set, and transfer backbone path equipment set; the switch station information includes switch station identifier, automatic transfer switch (bus tie switch), opposite power supply information, switch station incoming and outgoing backbone switches, switch station backbone switches, and branch strategy. Based on the returned self-healing and automatic transfer strategy, the set of automatic transfer switches currently in the activated state is identified. The specific identification method is as follows:

[0083] Line self-healing activation determination: Traverse the power supply backbone equipment set and the transfer backbone equipment set in the power supply path. For each distribution network bus equipment, query whether the equipment exists in the protection device to signal type mapping and whether the signal type is a line self-healing signal. If it exists, further query the line self-healing signal mapping to obtain the measurement point, and then obtain the signal value from the measurement point to signal value mapping. If the signal value is 1 (representing activation), the bus self-healing function is activated. If all switch station bus self-healing is activated, the line self-healing strategy can be executed.

[0084] Automatic transfer switch activation determination: Iterate through the automatic transfer policies of each switch station. For each automatic transfer switch, check if the switch exists in the protection device-to-signal type mapping and if the signal type is automatic transfer signal. If it exists, further query the automatic transfer signal mapping to obtain the measurement point, and then obtain the signal value from the measurement point-to-signal value mapping. If the signal value is 1, the automatic transfer function of the switch station is activated. At the same time, check if the bus associated with the switch exists in the bus-level automatic transfer signal mapping. If it exists, the automatic transfer function of the switch station is blocked by the bus configuration and is not activated.

[0085] Self-healing and automatic transfer judgment of power distribution room: Traverse the branch strategy of switch station. For the self-healing switch of power distribution room, check whether the switch exists in the mapping of protection device to signal type and the signal type is switch self-healing signal. If it exists, check the line self-healing signal mapping to obtain the measurement point, and then obtain the signal value from the mapping of measurement point to signal value. If the signal value is 1, the self-healing function of power distribution room is activated.

[0086] Step 3: Construct the network node admittance matrix considering switching actions. Based on the self-healing and self-transfer switch set and power transfer strategy identified in Step 2, determine the switching action sequence, i.e., which switches switch from off to on or from on to off. Update the network topology connections based on the switching action results and recalculate the node admittance matrix. The formula for calculating the node admittance matrix is:

[0087]

[0088]

[0089] Where is the self-admittance of the node, is the mutual admittance between nodes, is the branch admittance between nodes (if there is no direct branch between two nodes), and is the admittance of the node to ground branch (such as line to ground capacitance, transformer excitation branch, etc.).

[0090] Step 4: Perform power flow calculations for the distribution network using the optimal multiplier method. This invention establishes the nodal power balance equations in rectangular coordinates. Let the nodes... The real and imaginary parts of the voltage are respectively and Node admittance matrix elements Then the node active power and reactive power satisfy:

[0091]

[0092]

[0093] For the PQ node, and are known; for the PV node, and voltage magnitudes are known, but reactive power is to be determined. Construct the modified equations of the Newton-Raphson method:

[0094]

[0095] in, Let J be the nodal unbalanced power vector, and J be the Jacobian matrix. This is the voltage correction amount.

[0096] Due to insufficient measurement configuration and low observability in distribution networks, coupled with issues such as noise, missing data, and asynchronous measurement data, traditional Newton-Faraday matrices may exhibit ill-conditioned behavior and iterative divergence. To improve convergence, optimal multipliers are introduced. The state variable correction is expressed as:

[0097]

[0098]

[0099] Define the objective function as the sum of squares of nodal imbalance powers:

[0100]

[0101] Where and are functions of and . Expanded into a cubic polynomial:

[0102]

[0103] The coefficients are calculated as follows:

[0104]

[0105]

[0106]

[0107]

[0108] Where and are the unbalanced power at time , i.e., the values ​​at the current iteration point. The derivatives of and can be obtained by substituting the voltage expression into the power equation and taking the derivative. Taking the derivative of and setting it to zero:

[0109]

[0110] Solving the above quadratic equation yields candidate values ​​for the optimal multipliers:

[0111]

[0112] The optimal multiplier is selected as the solution that minimizes the positive real number. If the obtained multiplier decreases the objective function, then this step size is used to update the voltage; otherwise, the standard Newton step size is used. This iteration is repeated until convergence. The optimal multiplier method, by adaptively adjusting the step size, effectively suppresses the impact of data quality issues on the iteration process and significantly improves convergence reliability.

[0113] Step 5: Dynamically monitor the status changes of the self-healing and automatic transfer switch. To simulate multiple actions that the self-healing and automatic transfer device may take (such as timing coordination, reclosing, etc.), a detection period (e.g., 1-5 seconds) is set during the power flow iteration process. Each period reads the distribution network protection signal table through the real-time database interface to obtain the latest switch status signal value. A differential comparison method is used to detect switch status changes: the difference between the current period's signal value and the previous period's signal value is calculated. If the absolute value of the difference is greater than zero, it is determined that the switch status has changed, triggering the topology update flag. When the topology update flag is set, the current power flow iteration is immediately stopped, and the self-healing and automatic transfer strategy is re-requested from the topology service to obtain the latest switch status and transfer path. A hot-start method is used to initialize the power flow calculation, that is, the previously converged power flow solution is used as the initial value, and steps three to four are re-executed to accurately simulate the actual power flow distribution after the self-healing and automatic transfer device's action. If no switch change is detected, the current iteration continues until convergence.

[0114] Step Six: State Assessment and Result Output. After the power flow calculation converges, based on the obtained node voltages... , Calculate the voltage amplitude at each node. and phase angle :

[0115]

[0116]

[0117] Check if the node voltage exceeds the limit. The criterion for exceeding the voltage limit is:

[0118]

[0119] Calculate the power distribution of each branch:

[0120]

[0121] Where is the branch current and is the branch admittance. Calculate the system network loss:

[0122]

[0123]

[0124] It outputs indicators such as node voltage, branch power, and network loss, and generates voltage over-limit alarm information. These results can be used to assess the impact of self-healing and automatic transfer actions on the distribution network operation status, providing decision support for dispatching and operation personnel.

[0125] The optimal multiplier method distribution network power flow calculation system integrating self-healing and self-switching dynamic topology identification described in this invention includes:

[0126] The data acquisition module is used to collect real-time distribution network operation data and self-healing and automatic transfer device status information. By parsing the protection signal table, it identifies the self-healing and automatic transfer signal types of the remote automation device, and constructs the correlation mapping relationship between the signal and the primary distribution model in the system. This is used for subsequent signal parsing, correction of the power grid status, and automatic update of the power grid flow.

[0127] The topology identification module is used to dynamically identify the current distribution network topology based on the self-healing and automatic transfer action signal, and to construct the node admittance matrix after the switch action.

[0128] The power flow calculation module, based on the traditional power flow calculation method Newton-Raphson method, introduces an improved power flow calculation method, the optimal multiplier method, for distribution network power flow calculation;

[0129] The dynamic monitoring module is used to dynamically monitor the state changes of self-healing and self-transfer switches during power flow iteration. When a switch action is detected, the network topology is automatically updated and the power flow calculation is reinitialized.

[0130] The status assessment module is used to assess the operating status of the distribution network after self-healing and automatic switching actions based on the power flow calculation results, and outputs node voltage, branch power and network loss indicators.

[0131] The computer-readable storage medium of the present invention stores a computer program thereon, which, when executed by a processor, implements the steps of the above-described method.

Claims

1. A method for calculating power flow in distribution networks using the optimal multiplier method, which integrates self-healing and self-switching dynamic topology identification, characterized in that: include Real-time acquisition of power distribution network operation data and self-healing or automatic transfer status information of remote automation devices; identification of self-healing and automatic transfer signal types of remote automation devices by parsing protection signal tables; and construction of the correlation mapping relationship between signals and the primary power distribution model in the system. Based on the self-healing and automatic transfer action signal, the current distribution network topology is dynamically identified, and the node admittance matrix after the switch action is constructed. Based on the Newton-Raphson method for power flow calculation, an improved power flow calculation method is introduced to perform power flow calculation in distribution networks. During the power flow iteration process, the state changes of the self-healing and self-transfer switch are dynamically monitored. When a switch action is detected, the network topology is automatically updated and the power flow calculation is reinitialized. The power flow calculation results are used to evaluate the operating status of the distribution network after the self-healing and automatic switching action, and output node voltage, branch power and network loss indicators.

2. The optimal multiplier method for distribution network power flow calculation based on self-healing and self-switching dynamic topology identification as described in claim 1, characterized in that, The current distribution network topology is dynamically identified based on the self-healing and automatic transfer action signals, as detailed below: Request a self-healing and self-transfer policy from the topology service, and identify the set of self-healing and self-transfer switches that are currently in the activated state based on the returned self-healing and self-transfer policy. The self-healing and automatic transfer strategy includes equipment identification, execution success indicator, failure reason, original power supply information, fault equipment isolation scheme, local power supply range, line self-healing strategy transfer path and switch station automatic transfer strategy; The self-healing strategy for power transfer includes operating switches, loop fault isolation switches, power transfer information, power supply backbone equipment set, and power transfer backbone equipment set. The automatic transfer strategy for switch stations includes switch station identification, automatic transfer switches, power supply information on the opposite side, main switches entering and exiting the switch station, main switches of the switch station, and branch strategies.

3. The optimal multiplier method for distribution network power flow calculation based on self-healing and self-switching dynamic topology identification as described in claim 2, is characterized in that... The method for identifying the status of self-healing automatic transfer switches is as follows: Line self-healing activation judgment: Traverse the power supply backbone equipment set and the transfer backbone equipment set in the power supply path. For each distribution network bus equipment, check whether the equipment exists in the protection device to signal type mapping and whether the signal type is a line self-healing signal. If it exists, further query the line self-healing signal mapping to obtain the measurement point. Obtain the signal value from the measurement point to the signal value mapping. If the signal value is one, the self-healing function of the distribution network bus is activated. If the signal value is not one, the line self-healing function is deactivated, and the power supply will not be automatically restored through the tie switch after the line loses power. If the equipment does not exist in the protection device to signal type mapping or the signal type is not a line self-healing signal, the self-healing function of the distribution network substation is deactivated by default. If the self-healing of all distribution network substation busbars is activated, the line self-healing strategy can be executed. Automatic transfer switch activation judgment: Iterate through the automatic transfer strategies of each substation. For each automatic transfer switch, check if the switch exists in the mapping from protection device to signal type and if the signal type is automatic transfer signal. If it exists, further query the automatic transfer signal mapping to obtain the measurement point. Obtain the signal value from the mapping from the measurement point to the signal value. If the signal value is one, the automatic transfer function of the substation is activated. If the signal value is not one, the automatic transfer function of the substation is deactivated. After power failure, the backup automatic transfer switch will not be automatically closed to restore power supply. If the switch does not exist in the mapping from protection device to signal type or the signal type is not automatic transfer signal, the automatic transfer function of the distribution network substation is deactivated by default. At the same time, check if the bus associated with the switch exists in the bus-level automatic transfer signal mapping. If it exists, the automatic transfer of the substation is blocked by the bus configuration. If it does not exist, the operation logic of the switch is not affected by other bus configurations. Substation self-healing and automatic transfer judgment: Traverse the branch strategy of the switch station. For the self-healing switch of the substation, check whether the switch exists in the mapping of protection devices to signal types and whether the signal type is a switch self-healing signal. If it exists, check the line self-healing signal mapping to obtain the measurement point. Obtain the signal value from the mapping of the measurement point to the signal value. If the signal value is one, the substation self-healing function is activated. If the signal value is not one, the substation self-healing function is deactivated. When the substation loses power, the substation tie switch will not be closed to restore power supply. If the switch does not exist in the mapping of protection devices to signal types or the signal type is not a switch self-healing signal, the self-healing function logic is blocked.

4. The optimal multiplier method for distribution network power flow calculation based on self-healing and self-switching dynamic topology identification as described in claim 1, characterized in that, Based on the self-healing and automatic transfer action signals, the current distribution network topology is dynamically identified, and the node admittance matrix after the switch action is constructed, as follows: Based on the identified self-healing or automatic transfer switch signals, the actual switch self-healing or automatic transfer logic action strategy can be simulated and the switch action sequence can be determined in all power transfer strategies according to the priority of the line, switch station, and distribution room, as well as the start or stop status of the self-healing and automatic transfer signals. The network topology is updated based on the switching action results, and the node admittance matrix is ​​recalculated. The formula for calculating the node admittance matrix is ​​as follows: ； ； in, For nodes Self-guided absorbance, For nodes With nodes Mutual admittance between them , For nodes With nodes Branch admittance between For nodes Admittance of the ground branch.

5. The optimal multiplier method for distribution network power flow calculation based on self-healing and self-switching dynamic topology identification as described in claim 1, characterized in that, Based on the Newton-Raphson method for power flow calculation, an improved power flow calculation method is introduced to perform distribution network power flow calculation, as detailed below: Establish the power balance equations in rectangular coordinate form for power flow calculation in distribution networks: ； ； in, For nodes active power, For nodes reactive power, and Representing nodes respectively The real and imaginary parts of voltage, and Let represent the real and imaginary parts of the nodal admittance matrix, respectively; Construct the modified equations for the Newton-Raphson method: ； in, Let J be the nodal unbalanced power vector, and J be the Jacobian matrix. This is the voltage correction amount; Introducing the optimal multiplier The state variable correction is expressed as ； ； in, and These represent the corrected nodes. The real and imaginary parts of voltage; The optimal multiplier is found by minimizing the objective function. The objective function for 。 6. The optimal multiplier method for distribution network power flow calculation based on self-healing and self-switching dynamic topology identification as described in claim 5, is characterized in that... Optimal multiplier The solution process is as follows: Objective function Expanded into a cubic polynomial: ； ； ； ； ； in, , , and For parameters; For the objective function Differentiate and set it to zero: Obtain the optimal multiplier Candidate values: Choose the objective function The smallest positive real solution is taken as the optimal multiplier.

7. The optimal multiplier method for distribution network power flow calculation based on self-healing and self-switching dynamic topology identification as described in claim 1, characterized in that, During the power flow iteration process, the state changes of the self-healing and self-transfer switch are dynamically monitored. When a switch action is detected, the network topology is automatically updated and the power flow calculation is reinitialized, as follows: Set the power flow calculation time step, and read the distribution network protection signal table through the real-time database interface in each calculation cycle; use the differential comparison method to detect the switch state change: calculate the difference between the current cycle signal value and the previous cycle signal value; If the absolute value of the difference is greater than zero, it is determined that the switch state has changed, triggering the topology update flag; When the topology update flag is set, the current power flow iteration is stopped, the self-healing and self-reintroduction strategy is requested again from the topology service, and the power flow calculation is initialized in a hot-start manner.

8. The optimal multiplier method for distribution network power flow calculation based on self-healing and self-switching dynamic topology identification as described in claim 6, is characterized in that... During the power flow iteration process, the state changes of the self-healing and self-transfer switch are dynamically monitored, as follows: Calculate the voltage amplitude at each node. and phase angle : Check if the node voltage exceeds the limit. The criterion for exceeding the voltage limit is: Calculate the power distribution of each branch : Calculate network loss in the computing system: in, The minimum voltage amplitude at the i-th node. The maximum voltage amplitude at the i-th node. Let be the conjugate of the branch current phasor flowing from node i to node j. Let be the conjugate of the voltage difference between node i and node j. Let i be the conjugate of the mutual admittance between nodes i and j. Indicates taking the real part, This indicates taking the imaginary part. For the system's active power loss, This refers to the system's reactive power loss.

9. A distribution network power flow calculation system integrating self-healing and self-switching dynamic topology identification, characterized in that, include The data acquisition module is used to collect real-time distribution network operation data and self-healing and automatic transfer device status information. It identifies the signal types and statuses of line self-healing, switch station automatic transfer, and bus self-healing by parsing the protection signal table. Based on the data of the protection signals of each remote transmission device, it constructs the action logic of the actual field device self-healing or automatic transfer. The topology identification module is used to dynamically identify the current distribution network topology based on the self-healing and automatic transfer action signal, and to construct the node admittance matrix after the switch action. The power flow calculation module, based on the traditional power flow calculation method Newton-Raphson method, introduces an improved power flow calculation method, the optimal multiplier method, for distribution network power flow calculation; The dynamic monitoring module is used to dynamically monitor the state changes of self-healing and self-transfer switches during power flow iteration. When a switch action is detected, the network topology is automatically updated and the power flow calculation is reinitialized. The status assessment module is used to assess the operating status of the distribution network after self-healing and automatic switching actions based on the power flow calculation results, and outputs node voltage, branch power and network loss indicators.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1-8.

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