Switch cabinet digital twin dynamic modeling method based on multi-physical field coupling

Abstract

The application provides a switch cabinet digital twin dynamic modeling method based on multi-physical field coupling, which establishes an electromagnetic field sub-model, a temperature field sub-model and an airflow field sub-model according to switch cabinet structure parameters, and realizes multi-physical field coupling through conductive component loss, solid surface temperature and convective heat transfer conditions; determines the physical field sub-model, simulation boundary and field transmission data that need to be updated according to the change of the operating state, and the sub-models that do not change in parameters or boundaries inherit the state quantity of the last modeling period; after the coupling solution is completed, the difference between the measured temperature and the calculated temperature is used to correct the corresponding model parameters, and the conductive component loss distribution, the cabinet temperature distribution and the cabinet air flow distribution are obtained. The method can make the model update content correspond to the actual operation change of the switch cabinet, and reduce the repeated calculation of the unchanged model state.

Description

Technical Field

[0001] This invention relates to the field of switchgear operation status modeling technology, and in particular to a switchgear digital twin dynamic modeling method based on multi-physics coupling. Background Technology

[0002] When the switchgear is in operation, the busbars, contacts and other conductive components will generate heat. The temperature inside the cabinet is also affected by air flow, ventilation conditions and the external environment. Therefore, there is an interaction between its electrical state, temperature field and airflow field.

[0003] Existing technologies have applied digital twins to switchgear status analysis. For example, patent application CN115347673A discloses a digital twin system diagnostic method applicable to power distribution switchgear. It establishes a virtual mapping model by collecting equipment status data and combines simulation results to perform status diagnosis and prediction.

[0004] Existing methods typically predefine the transmission relationships between various physical fields and perform calculations according to fixed boundary conditions and parameters. In actual operation, the load, switching status, contact status, and ventilation conditions of the switchgear will change, and the physical fields affected by different changes are not the same. If a fixed coupling relationship and a uniform update method are still used, it will be difficult to determine the physical fields that need to be recalculated and the model parameters that need to be adjusted based on the current operating status, so that the model update cannot fully correspond to the actual changes of the physical switchgear.

[0005] To address this, a dynamic modeling method for digital twins of switchgear based on multi-physics coupling is proposed. Summary of the Invention

[0006] In view of this, the present invention provides a method for dynamic modeling of digital twins of switchgear based on multi-physics coupling, so as to solve or alleviate the technical problems existing in the prior art, and at least provide a beneficial option.

[0007] The technical solution of this invention is implemented as follows: a dynamic modeling method for digital twin of switchgear based on multi-physics coupling, comprising the following steps: S1. Establish a geometric model based on the structural parameters of the switchgear, and establish an electromagnetic field sub-model, a temperature field sub-model, and an airflow field sub-model based on the geometric model. Transfer the conductive component loss calculated by the electromagnetic field sub-model to the temperature field sub-model as the heat source condition for solving the temperature field. Transfer the solid surface temperature calculated by the temperature field sub-model to the airflow field sub-model as the thermal boundary condition for solving the airflow field. Transfer the convective heat transfer condition calculated by the airflow field sub-model to the temperature field model to form a multi-physics coupling model. S2. Obtain the real-time operating data of the switchgear in the current modeling cycle, and compare the real-time operating data with the operating data of the previous modeling cycle to obtain the operating status change information; S3. The change in operating state information is determined to be an electrical state change or a heat dissipation state change. When an electrical state change occurs, the electromagnetic field sub-model that needs to be updated, the conductive component loss transmitted from the electromagnetic field sub-model to the temperature field sub-model, and the current boundary or conductive topology corresponding to the change in electrical state are determined. When a heat dissipation state change occurs, the airflow field sub-model that needs to be updated, the convective heat transfer conditions transmitted from the airflow field sub-model to the temperature field model, and the airflow field boundary corresponding to the change in heat dissipation state are determined. S4. Update the physical field sub-models, inter-field transfer data, model parameters and simulation boundaries determined in S3. For physical field sub-models not included in the update range of model parameters or simulation boundaries, use the state variables obtained from the previous modeling cycle as the initial state variables of the current modeling cycle. S5. Solve the multi-physics coupling model according to the updated physical field sub-model and inter-field transfer data to obtain the digital twin state of the switchgear in the current modeling cycle.

[0008] More preferably, the real-time operating data includes load current, switch on / off status, temperature at measuring points inside the cabinet, ambient temperature, and cabinet ventilation status data; When the load current changes relative to the previous modeling cycle or the switch opening / closing state changes, the change in operating state information is determined as an electrical state change; when the ambient temperature changes relative to the previous modeling cycle or the cabinet ventilation state changes, the change in operating state information is determined as a heat dissipation state change. When the load current changes, the current boundary of the electromagnetic field sub-model is adjusted according to the load current of the current modeling cycle, and the loss of the conductive components of the switch cabinet is recalculated; when the switch opening and closing state changes, the on / off state of the corresponding conductive connection relationship in the electromagnetic field sub-model is adjusted according to the current switch opening and closing state, and the loss of the conductive components is recalculated according to the adjusted conductive topology. When a change in heat dissipation occurs, the ambient temperature boundary of the airflow field sub-model is adjusted according to the current ambient temperature, and at least one of the air inlet boundary and air outlet boundary of the airflow field sub-model is adjusted according to the current cabinet ventilation state. The air flow state and convective heat transfer conditions inside the cabinet are then recalculated according to the adjusted airflow field boundary.

[0009] More preferably, the conductive component includes at least one of a main busbar, a circuit breaker contact, and a cable connection portion, and the loss of the conductive component includes conductor loss and contact loss.

[0010] More preferably, when the electromagnetic field sub-model is not updated in the current modeling cycle, the loss of conductive components calculated in the previous modeling cycle is used as the heat source condition of the temperature field sub-model; when the airflow field sub-model is not updated in the current modeling cycle, the convective heat transfer condition calculated in the previous modeling cycle is used as the heat transfer boundary condition of the temperature field sub-model.

[0011] In a further preferred embodiment, when a physical field sub-model that is not included in the model parameter or simulation boundary update range receives inter-field transfer data recalculated by other physical field sub-models, it replaces the corresponding data of the previous modeling cycle with the recalculated inter-field transfer data and participates in the multi-physics coupling solution of the current modeling cycle.

[0012] In a further preferred embodiment, after obtaining the digital twin state of the switchgear in the current modeling cycle, the temperature difference between the actual temperature of the measuring point inside the cabinet and the calculated temperature at the corresponding position in the temperature field sub-model is calculated. The model parameters in S3 corresponding to the change in the current operating state are then corrected based on the temperature difference, and the corrected model parameters are used to solve the multiphysics coupling model.

[0013] More preferably, the digital twin state of the switchgear includes the loss distribution of conductive components, the temperature distribution inside the cabinet, and the airflow distribution inside the cabinet.

[0014] The embodiments of the present invention have the following advantages due to the adoption of the above technical solutions: I. This invention updates the corresponding electromagnetic field sub-model, airflow field sub-model, inter-field transfer data, and simulation boundaries according to changes in load current, switch open / closed state, ambient temperature, and cabinet ventilation state, so that the model adjustment content corresponds to the current operating state of the switch cabinet.

[0015] Second, for physical field sub-models that have not undergone parameter or boundary changes in the current modeling cycle, the state variables, conductive component losses, or convective heat transfer conditions of the previous modeling cycle are used, and they continue to participate in the coupling solution after receiving new inter-field transfer data, thereby reducing redundant calculations.

[0016] Third, this invention utilizes the difference between the actual temperature at the measuring point inside the cabinet and the temperature calculated by the model to correct the model parameters related to the current changes in electrical state or heat dissipation state, which helps to reduce the state deviation between the digital twin model and the physical switch cabinet. Attached Figure Description

[0017] Figure 1 This is a flowchart of the dynamic modeling method steps of the present invention. Detailed Implementation

[0018] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0019] like Figure 1 As shown, this embodiment of the invention provides a method for dynamic modeling of digital twins of switchgear based on multi-physics coupling. The method is based on the structural parameters and real-time operating data of the switchgear. It establishes electromagnetic field sub-models, temperature field sub-models and airflow field sub-models in the same geometric model. According to the actual state changes of the switchgear, the corresponding model inputs, simulation boundaries and inter-field transfer data are adjusted. For models not involved in the current state changes, the solution results of the previous modeling cycle are used as the basis for the current calculation. When the transfer data updated by other physics fields is received, it will participate in the current coupling solution.

[0020] In this embodiment, the modeling cycle refers to a single processing step that begins with the acquisition of running data and sequentially completes the state change judgment, model update, and coupled solution. Adjacent modeling cycles are executed consecutively, and the running data, model state, and inter-field transfer data saved in the previous cycle serve as the basis for comparison and continued calculation in the next cycle.

[0021] In this embodiment, the structural parameters of the switchgear to be modeled are obtained, and a geometric model is established accordingly. The geometric model includes at least the cabinet body, conductive components, insulating support parts, and air circulation space inside the cabinet. The conductive components include at least one of the main busbar, circuit breaker contacts, and cable connection parts.

[0022] An electromagnetic field sub-model is established on the geometric model. The electromagnetic field sub-model is used to calculate the loss generated when the load current flows through the conductive components. For continuous conductor regions, the corresponding conductor loss is calculated. For contacts and cable connection parts, the contact loss can also be included in the corresponding position. The conductive component loss obtained from the electromagnetic field sub-model is transferred to the temperature field sub-model according to its spatial position, as the heat source condition of the corresponding region.

[0023] The temperature field sub-model calculates the temperature state based on the losses of conductive components and the heat transfer relationship between the solid structures of the switch cabinet, and transfers the calculated solid surface temperature to the airflow field sub-model as the thermal boundary condition for airflow and heat transfer calculation.

[0024] The airflow field sub-model is established on the air circulation space and ventilation area inside the cabinet. It calculates the airflow inside the cabinet by combining the ambient temperature, air intake and air exhaust conditions, and obtains the convective heat transfer conditions on the solid surface. The convective heat transfer conditions are then transferred to the temperature field sub-model to update the corresponding heat transfer boundaries.

[0025] In this way, the electromagnetic field sub-model transmits the losses of conductive components to the temperature field sub-model, the temperature field sub-model transmits the solid surface temperature to the airflow field sub-model, and the airflow field sub-model feeds back the convective heat transfer conditions to the temperature field model, thus forming a multi-physics coupling relationship.

[0026] After completing the basic model, the actual temperature measurement points inside the switch cabinet are associated with the corresponding positions in the temperature field sub-model, and the load current, switch opening and closing status, ambient temperature and cabinet ventilation status are respectively mapped to the relevant model inputs or simulation boundaries.

[0027] In this embodiment, at the beginning of each modeling cycle, real-time operating data of the switchgear is collected. The real-time operating data includes load current, switch open / closed status, temperature of measuring points inside the cabinet, ambient temperature, and cabinet ventilation status data. After obtaining the data of the current cycle, it is compared with the data saved in the previous modeling cycle.

[0028] When the load current changes or the switch opening / closing state changes, it is determined as an electrical state change; when the ambient temperature changes or the cabinet ventilation state changes, it is determined as a heat dissipation state change.

[0029] Electrical state changes and heat dissipation state changes can occur separately or simultaneously within the same modeling cycle. When only electrical state changes occur, the electromagnetic field sub-model and the losses of conductive components transmitted to the temperature field sub-model are mainly adjusted. When only heat dissipation state changes occur, the airflow field sub-model and the convective heat transfer conditions fed back to the temperature field model are mainly adjusted.

[0030] In this embodiment, when the load current changes, the current boundary of the electromagnetic field sub-model is adjusted according to the load current collected in the current modeling cycle, and the loss of conductive components is recalculated. At this time, if the switch opening and closing state does not change, the original conductive topology can continue to be used without resetting the conductive connection relationship.

[0031] The recalculated losses of conductive components are transferred to the temperature field sub-model, replacing the heat source conditions of the corresponding region in the previous modeling cycle. The temperature field sub-model uses the temperature state at the end of the previous cycle as the initial state of the current cycle and continues the calculation under the new heat source conditions, instead of starting from the initial ambient temperature again.

[0032] When the switch state changes, the on / off state of the corresponding conductive connection in the electromagnetic field sub-model is adjusted according to the current switch state; after the conductive topology is updated, the loss of conductive components under the current conductive path is recalculated and the obtained loss is transferred to the temperature field sub-model.

[0033] If the load current and the switch open / closed state change simultaneously, the conductive topology can be updated according to the current switch state first, then the current load current boundary can be set, and then the losses of conductive components can be calculated.

[0034] When the change in electrical state itself does not alter the airflow field boundary, the airflow field sub-model can still use the original ambient temperature and ventilation boundary; however, after the temperature field sub-model calculates the new solid surface temperature, the airflow field sub-model still needs to receive the temperature data and participate in this round of coupling calculation accordingly.

[0035] In this embodiment, when the ambient temperature changes, the currently collected ambient temperature is written into the airflow field sub-model to replace the ambient temperature boundary of the previous cycle; when the ventilation state of the cabinet changes, at least one of the air inlet boundary and air outlet boundary is adjusted according to the current ventilation situation.

[0036] After the boundary adjustment is completed, the airflow field sub-model re-solves the airflow state inside the cabinet in combination with the current solid surface temperature and obtains the updated convective heat transfer conditions; the convective heat transfer conditions are then transferred to the temperature field sub-model to replace the heat transfer boundary at the corresponding position in the previous cycle.

[0037] If only the heat dissipation state changes in this cycle, and the load current and switch opening / closing state remain unchanged, then the electromagnetic field sub-model does not need to be recalculated, and the conductive component losses obtained in the previous cycle continue to be used as the heat source conditions for the temperature field sub-model.

[0038] When the ambient temperature and the cabinet ventilation status change simultaneously, the corresponding boundary adjustments can be completed within the same modeling cycle, and then the airflow field sub-model can be solved in a unified manner.

[0039] In this embodiment, when the electromagnetic field sub-model is not updated in the current modeling cycle, the conductive component loss calculated in the previous modeling cycle is used as the heat source condition of the temperature field sub-model; when the airflow field sub-model is not updated in the current modeling cycle, the convective heat transfer condition obtained in the previous modeling cycle is used as the heat transfer boundary of the temperature field sub-model.

[0040] For physical field sub-models that are not included in the model parameters or simulation boundary update range, the state variables at the end of the previous modeling cycle are used as the initial state variables for the current cycle.

[0041] For example, when only the load changes, the airflow field sub-model does not adjust the ventilation boundary, but after receiving the solid surface temperature recalculated by the temperature field sub-model, it still needs to participate in the airflow and heat transfer calculations according to the new temperature data; similarly, when only the ambient temperature changes, the electromagnetic field sub-model can use the original conductive component losses, while the temperature field sub-model continues to solve according to the new convection heat transfer conditions.

[0042] Therefore, data from the previous modeling cycle is only retained if it has not become invalid due to changes in the current operation; once new coupling data is received from other physics fields, the relevant sub-models continue to calculate according to the updated data.

[0043] In this embodiment, after completing the coupled solution of the current modeling cycle, the calculated temperature corresponding to the actual temperature measurement point is extracted from the temperature field sub-model and compared with the actual temperature collected in the same cycle to obtain the temperature difference.

[0044] When an electrical state change occurs during the cycle, model parameters related to the losses of conductive components are corrected based on the temperature difference; when a heat dissipation state change occurs during the cycle, model parameters related to convective heat transfer conditions are corrected based on the temperature difference. The parameter correction range corresponds to the current state change, and irrelevant model parameters are not uniformly adjusted.

[0045] After parameter calibration, the multiphysics coupling model is re-solved using the calibrated model parameters; the specific parameter adjustment range can be determined based on the actual switchgear structure, material properties, and measurement point layout.

[0046] The final digital twin state of the switchgear obtained in the current modeling cycle includes the loss distribution of conductive components, the temperature distribution inside the cabinet, and the airflow distribution inside the cabinet. The above results are saved at the end of this cycle and used as the basis for comparing running data, inheriting model state, and updating inter-field data in the next modeling cycle.

[0047] This invention adjusts the corresponding physical field sub-models, simulation boundaries, and inter-field transfer data according to the actual changes in the electrical and heat dissipation states of the switchgear. The model states that are not affected in the current round are retained and continue to participate in the coupling solution when other physical field updated data are received, so that the model update process corresponds to the current operating conditions of the switchgear.

[0048] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in the present invention, and these should all be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for dynamic modeling of digital twins of switchgear based on multi-physics coupling, characterized in that, Includes the following steps: S1. Establish a geometric model based on the structural parameters of the switchgear, and establish an electromagnetic field sub-model, a temperature field sub-model, and an airflow field sub-model based on the geometric model. Transfer the conductive component loss calculated by the electromagnetic field sub-model to the temperature field sub-model as the heat source condition for solving the temperature field. Transfer the solid surface temperature calculated by the temperature field sub-model to the airflow field sub-model as the thermal boundary condition for solving the airflow field. Transfer the convective heat transfer condition calculated by the airflow field sub-model to the temperature field model to form a multi-physics coupling model. S2. Obtain the real-time operating data of the switchgear in the current modeling cycle, and compare the real-time operating data with the operating data of the previous modeling cycle to obtain the operating status change information; S3. The change in operating state information is determined to be an electrical state change or a heat dissipation state change. When an electrical state change occurs, the electromagnetic field sub-model that needs to be updated, the conductive component loss transmitted from the electromagnetic field sub-model to the temperature field sub-model, and the current boundary or conductive topology corresponding to the change in electrical state are determined. When a heat dissipation state change occurs, the airflow field sub-model that needs to be updated, the convective heat transfer conditions transmitted from the airflow field sub-model to the temperature field model, and the airflow field boundary corresponding to the change in heat dissipation state are determined. S4. Update the physical field sub-models, inter-field transfer data, model parameters and simulation boundaries determined in S3. For physical field sub-models not included in the update range of model parameters or simulation boundaries, use the state variables obtained from the previous modeling cycle as the initial state variables of the current modeling cycle. S5. Solve the multi-physics coupling model according to the updated physical field sub-model and inter-field transfer data to obtain the digital twin state of the switchgear in the current modeling cycle.

2. The method for dynamic modeling of switchgear digital twins based on multiphysics coupling according to claim 1, characterized in that, The real-time operating data includes load current, switch on / off status, temperature at measuring points inside the cabinet, ambient temperature, and cabinet ventilation status data.

3. The method for dynamic modeling of switchgear digital twins based on multiphysics coupling according to claim 2, characterized in that, When the load current changes relative to the previous modeling cycle or the switch opening / closing state changes, the change in operating state information is determined as an electrical state change; when the ambient temperature changes relative to the previous modeling cycle or the cabinet ventilation state changes, the change in operating state information is determined as a heat dissipation state change.

4. The method for dynamic modeling of switchgear digital twins based on multiphysics coupling according to claim 3, characterized in that, When the load current changes, the current boundary of the electromagnetic field sub-model is adjusted according to the load current of the current modeling cycle, and the loss of the conductive components of the switch cabinet is recalculated. When the switch opening and closing state changes, the on / off state of the corresponding conductive connection relationship in the electromagnetic field sub-model is adjusted according to the current switch opening and closing state, and the loss of the conductive components is recalculated according to the adjusted conductive topology.

5. The method for dynamic modeling of switchgear digital twins based on multiphysics coupling according to claim 3, characterized in that, When a change in heat dissipation occurs, the ambient temperature boundary of the airflow field sub-model is adjusted according to the current ambient temperature, and at least one of the air inlet boundary and air outlet boundary of the airflow field sub-model is adjusted according to the current cabinet ventilation state. The air flow state and convective heat transfer conditions inside the cabinet are then recalculated according to the adjusted airflow field boundary.

6. The method for dynamic modeling of switchgear digital twins based on multiphysics coupling according to claim 4, characterized in that, The conductive component includes at least one of the main busbar, circuit breaker contacts, and cable connection parts, and the loss of the conductive component includes conductor loss and contact loss.

7. The method for dynamic modeling of switchgear digital twins based on multiphysics coupling according to claim 1, characterized in that, When the electromagnetic field sub-model is not updated in the current modeling cycle, the loss of conductive components calculated in the previous modeling cycle is used as the heat source condition of the temperature field sub-model; when the airflow field sub-model is not updated in the current modeling cycle, the convective heat transfer condition calculated in the previous modeling cycle is used as the heat transfer boundary condition of the temperature field sub-model.

8. The method for dynamic modeling of switchgear digital twins based on multiphysics coupling according to claim 7, characterized in that, When a physical field sub-model that is not included in the model parameter or simulation boundary update range receives inter-field transfer data recalculated by other physical field sub-models, it replaces the corresponding data of the previous modeling cycle with the recalculated inter-field transfer data and participates in the multi-physics coupling solution of the current modeling cycle.

9. The method for dynamic modeling of switchgear digital twins based on multi-physics coupling according to claim 1, characterized in that, After obtaining the digital twin state of the switchgear in the current modeling cycle, the temperature difference between the actual temperature of the measuring point inside the cabinet and the calculated temperature at the corresponding position in the temperature field sub-model is calculated. The model parameters in S3 corresponding to the change in the current operating state are corrected based on the temperature difference. Then, the corrected model parameters are used to solve the multiphysics coupling model.

10. The method for dynamic modeling of switchgear digital twins based on multiphysics coupling according to claim 1, characterized in that, The digital twin state of the switchgear includes the loss distribution of conductive components, the temperature distribution inside the cabinet, and the airflow distribution inside the cabinet.

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