A multi-working condition simulation modeling and analysis system for direct current equipment of a converter station

Abstract

The application discloses a simulation modeling analysis system for multiple working conditions of a DC equipment in a converter station, and relates to the technical field of power simulation.The system comprises a fault scanning module, a model construction module and the like.The fault scanning module is used for performing short-circuit and grounding fault scanning in an AC / DC system electromechanical transient baseline project, and deploying a dynamic phasor traveling wave interface corridor on a boundary interconnection channel of a target object set to output a target object set configuration package.The model construction module is used for constructing a steady-state equivalent parameter model and a transient-state equivalent parameter model according to the target object set configuration package in an electromagnetic transient simulation project, and assembling the steady-state equivalent parameter model and the transient-state equivalent parameter model into a unified electromagnetic transient simulation project.The application can reduce the modeling range and configuration complexity of multiple working condition joint calculation by performing short-circuit and grounding fault scanning in the AC / DC system electromechanical transient baseline project through the fault scanning module and forming a target object set and a boundary interconnection marking table.

Description

Technical Field

[0001] This invention relates to the field of power simulation technology, and in particular to a multi-condition simulation modeling and analysis system for DC equipment in converter stations. Background Technology

[0002] As the scale of ultra-high voltage direct current (UHVDC) transmission projects expands, the transient assessment of DC equipment in converter stations has gradually expanded from single electromagnetic transient simulation to a joint analysis approach involving "AC / DC system electromechanical transient baseline engineering - electromagnetic transient simulation engineering - finite element simulation software". Common practices include applying short-circuit faults and grounding faults at the electromechanical transient level to screen operating modes, constructing component models such as surge arresters, DC filters, and wall bushings at the electromagnetic transient level to simulate lightning injection events, fault connection events, and switching events, and establishing severe weather boundary conditions for the external insulation of wall bushings in the finite element simulation software to obtain equivalent capacitance and equivalent leakage conductance for insulation condition assessment.

[0003] In engineering practice, existing methods often rely on manual determination of the object range and boundary equivalence methods. Furthermore, external equivalence access and boundary quantity exchange often use static equivalence or simplified interfaces, making it difficult to simultaneously meet the requirements of consistent traveling wave propagation delay and port equivalent impedance. This results in insufficient comparability of multi-condition calculation results across operating conditions in terms of port overvoltage characteristics, wavefront steepness characteristics, and filter branch current characteristics. At the same time, the lack of a closed-loop recalculation verification path of "multi-condition result package - electrical stress verification table - insulation verification record table - recalculation result package" makes it difficult to form a repeatable quantitative comparison basis for verification conclusions and measure adjustments. Summary of the Invention

[0004] In view of the aforementioned existing problems, the present invention is proposed.

[0005] Therefore, this invention provides a multi-condition simulation modeling and analysis system for converter station DC equipment to solve the problems of insufficient consistency of boundary quantities and incomplete modeling and verification closed loop in the multi-condition joint calculation of solution domains with large and small step sizes.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] This invention provides a multi-condition simulation modeling and analysis system for DC equipment in a converter station, which includes a fault scanning module that performs short-circuit and ground fault scanning in the electromechanical transient baseline engineering of the AC / DC system, deploys a dynamic phasor traveling wave interface corridor in the boundary communication channel of the target object set, and outputs a target object set configuration package.

[0008] The model building module constructs steady-state equivalent parameter models and transient equivalent parameter models according to the target object set configuration package in the electromagnetic transient simulation project, and assembles the steady-state equivalent parameter models and transient equivalent parameter models into a unified electromagnetic transient simulation project;

[0009] The solution exchange module performs real-time voltage and current exchange between the large-step solution domain and the small-step solution domain through the protocol conversion device and the communication link driving the dynamic phasor traveling wave interface corridor, and performs multi-condition joint calculation in the unified electromagnetic transient simulation project to obtain multi-condition result packages;

[0010] The result verification module performs a comparison between normal and special operating conditions on the multi-condition result package, completes the verification of insulation status and electrical stress, and performs recalculation verification, and outputs a verification evaluation report.

[0011] As a preferred embodiment of the multi-condition simulation modeling and analysis system for converter station DC equipment described in this invention, the step of performing short-circuit and ground fault scanning specifically includes:

[0012] The simulation center establishes an electromechanical transient baseline project for AC / DC systems and writes it into the operating mode parameter set and fault application rule set, generating a baseline operating rule table;

[0013] Short-circuit faults and ground faults are applied to key nodes around the converter station and key nodes of the receiving-end network according to the baseline operation rule table, and fault response records are generated.

[0014] Perform target fault determination on the fault response record, extract the nodes and lines involved in the fault that triggered the determination, generate a target fault association list, summarize the target fault association list and mark the external connection branches, and generate a target object set and boundary connection label table.

[0015] As a preferred embodiment of the multi-condition simulation modeling and analysis system for converter station DC equipment described in this invention, the target object set refers to the collection of converter station nodes, inverter station nodes, AC outgoing lines and lines that are associated with the stable operation of the DC system within the target fault association list.

[0016] As a preferred embodiment of the multi-condition simulation modeling and analysis system for converter station DC equipment described in this invention, the output target object set configuration package specifically comprises:

[0017] Based on the boundary connection labeling table, cross-set connection channels are extracted from the target object set, and dynamic phasor line corridor segments are established for each connection channel, generating a corridor port mapping table.

[0018] Based on the corridor port mapping table, write the traveling wave propagation delay parameters and port equivalent impedance parameters for each corridor segment to generate an interface corridor parameter file;

[0019] Write the interface corridor parameter file back to the target object set, lock the correspondence between the corridor port and the set boundary node, and generate the boundary corridor binding list;

[0020] Extract the access relationships between the external network and the boundary nodes from the boundary corridor binding list, and generate an external equivalent access table;

[0021] The target object set, interface corridor parameter file, and external equivalent access table are encapsulated, and a version number and consistency verification identifier are written into them, and the target object set configuration package is output.

[0022] As a preferred embodiment of the multi-condition simulation modeling and analysis system for converter station DC equipment described in this invention, the construction of the steady-state equivalent parameter model specifically includes:

[0023] In the electromagnetic transient simulation software, a target object set electromagnetic transient simulation project is established, and the target object set configuration package is loaded to complete the connection between the boundary corridor port and the equivalent access point outside the set, generating a unified topology project;

[0024] Within a unified topology project, each device port is connected to the DC bus and grounding terminal using a consistent connection method to generate a steady-state device model group.

[0025] Perform steady-state initialization verification on the steady-state device model group, generate a steady-state initialization state set, write the steady-state initialization state set into the unified topology project, and generate a steady-state equivalent parameter model.

[0026] As a preferred embodiment of the multi-condition simulation modeling and analysis system for converter station DC equipment described in this invention, the construction of the transient equivalent parameter model specifically involves:

[0027] Within the steady-state equipment model group, the transient nonlinear conduction branch and energy absorption measurement channel of the surge arrester are solidified, and the transient model file of the surge arrester is generated; the transient high-frequency branch and damping branch of the DC filter are solidified, and the transient model file of the filter is generated; the transient ground capacitance network and surface leakage branch of the through-wall bushing are solidified and an equivalent parameter write-back interface is reserved, and the bushing transient model file is generated.

[0028] The transient model files of surge arresters, filters, and bushings are solidified into a unified topology project in parallel according to the equipment port consistency rules, and the trigger mappings of lightning injection events, fault connection events, and switching events are written to generate a transient event mapping table.

[0029] Merge the transient event mapping table with the steady-state initialization state set to output the transient equivalent parameter model.

[0030] As a preferred embodiment of the multi-condition simulation modeling and analysis system for converter station DC equipment described in this invention, the real-time voltage and current exchange between the large-step solution domain and the small-step solution domain specifically includes:

[0031] The first protocol conversion device reads the interface corridor parameter file and corridor port mapping table from the target object set configuration package and generates a corridor port alignment table.

[0032] The second protocol conversion device reads the corridor port alignment table and establishes a mapping relationship between ports and communication frame fields, generating a communication frame mapping table;

[0033] The first protocol conversion device and the second protocol conversion device establish a real-time exchange channel through a communication link, send small-step solution domain port voltage and current according to the communication frame mapping table, and receive large-step solution domain port voltage and current to generate a real-time exchange data stream;

[0034] The dynamic phasor traveling wave interface corridor performs port updates with consistent propagation delay on the real-time exchanged data stream based on the interface corridor parameter file, and outputs the corridor boundary exchange status.

[0035] As a preferred embodiment of the multi-condition simulation modeling and analysis system for converter station DC equipment described in this invention, the step of performing multi-condition joint calculations in the unified electromagnetic transient simulation engineering specifically includes:

[0036] Invoke the corridor boundary exchange state to start the unified electromagnetic transient simulation project, load the steady-state initialization state set, and generate the joint calculation start state;

[0037] Based on the initial state of the joint calculation, lightning injection events are applied to the DC bus according to the same event sequence, and the transient event mapping table is triggered to input the corresponding transient sub-model to generate lightning strike waveform records.

[0038] Short-circuit ground fault events are initiated according to the same event sequence, and the fault branch is restored according to the preset clearing strategy. At the same time, the transient event mapping table is triggered to initiate the corresponding transient sub-model and generate ground fault operating condition waveform records.

[0039] Apply switching events according to the same event sequence, and trigger the transient event mapping table to input the corresponding transient sub-model to generate switching overvoltage condition waveform records;

[0040] In the finite element simulation software, a set of severe weather boundary conditions for the external insulation of the through-wall bushing is established, and the equivalent capacitance and equivalent leakage conductance are obtained. At the same time, the surface leakage branch and capacitance network are updated through the write-back interface of the bushing transient model file, and a severe weather parameter write-back record is generated.

[0041] The waveform records of lightning strike, ground fault, switching overvoltage, and severe weather parameters are encapsulated according to the device port index and event sequence index, and the multi-condition result package is output.

[0042] As a preferred embodiment of the multi-condition simulation modeling and analysis system for converter station DC equipment described in this invention, the comparison of normal and special conditions on the multi-condition result package specifically includes:

[0043] Extract the steady-state records of normal operating conditions and the waveform records of special operating conditions from the multi-condition result package, and align the time axis according to the steady-state initialization state set to generate an aligned waveform set;

[0044] Based on the device port index, generate a device-by-device, condition-by-condition comparison page within the aligned waveform set, and annotate the port overvoltage characteristics, wavefront steepness characteristics, and filter branch current characteristics to generate a set of condition comparison pages.

[0045] As a preferred embodiment of the multi-condition simulation modeling and analysis system for converter station DC equipment described in this invention, the completion of insulation state and electrical stress verification and recalculation specifically includes:

[0046] Extract surge arrester energy absorption records, port voltage stress records, and filter branch current records from the working condition comparison page set, and combine them with severe weather parameter write-back records to generate an electrical stress verification table.

[0047] The locations of hot spots of external insulation field strength output from finite element simulation are matched with the electrical stress verification table according to the wall bushing equipment index to generate an insulation verification record table;

[0048] Summarize the electrical stress verification table and insulation verification record table to form a verification conclusion;

[0049] Calling the verification conclusion, the same event sequence is reproduced in the unified electromagnetic transient simulation project, the multi-condition result package is regenerated and the aligned waveform set is updated to generate the recalculation result package;

[0050] The recalculated result package is compared with the original multi-condition result package, and a verification and evaluation report is output.

[0051] The beneficial effects of this invention are as follows: By performing short-circuit and ground fault scanning within the electromechanical transient baseline engineering of the AC / DC system through the fault scanning module, and forming a target object set and boundary connection annotation table, the subsequent electromagnetic transient simulation engineering only needs to model the converter station nodes, inverter station nodes, AC outgoing lines and lines involved in the target fault association list, reducing the modeling scope and configuration complexity of multi-condition joint calculation; by deploying a dynamic phasor traveling wave interface corridor in the boundary connection channel and writing the traveling wave propagation delay parameters and port equivalent impedance parameters, consistent port updates and equivalent boundary constraints with propagation delay are achieved, improving the real-time voltage and current in both large-step and small-step solution domains. Physical consistency of the exchange; by assembling the steady-state equivalent parameter model and the transient equivalent parameter model into a unified electromagnetic transient simulation project within a unified topology project, and using a transient event mapping table to uniformly manage the triggering paths of lightning injection events, fault input events, and switching events, the consistency of event sequences in multi-condition result packages is improved; by linking the alignment waveform set, condition comparison page set, electrical stress verification base table, and insulation verification record table, verification conclusions are formed and the same event sequence is reproduced to generate a recalculation result package, so that the verification evaluation report has repeatable difference comparison basis, thereby improving the verifiability and engineering feasibility of insulation state and electrical stress verification. Attached Figure Description

[0052] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 The flowchart is for a multi-condition simulation modeling and analysis system for DC equipment in a converter station.

[0054] Figure 2 This is a flowchart for fault scanning.

[0055] Figure 3 A flowchart for building the model.

[0056] Figure 4 The flowchart for solving the exchange and result verification. Detailed Implementation

[0057] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0058] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0059] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0060] Reference Figures 1-4 As one embodiment of the present invention, this embodiment provides a multi-condition simulation modeling and analysis system for DC equipment in a converter station, comprising the following steps:

[0061] The fault scanning module performs short-circuit and ground fault scanning in the electromechanical transient baseline engineering of AC / DC systems, deploys dynamic phasor traveling wave interface corridors in the boundary communication channels of the target object set, and outputs the target object set configuration package.

[0062] The electromechanical transient baseline engineering of AC / DC systems has completed the writing of the operating mode parameter set and the fault application rule set. The operating mode parameter set defines the topology closing status and power flow support mode of converter station nodes, inverter station nodes, AC outgoing lines and lines. The fault application rule set defines the fault type, fault location location method and fault duration configuration method of short circuit faults and ground faults. The operating mode parameter set and the fault application rule set together form the baseline operating rule table.

[0063] The baseline operation rule table applies short-circuit faults and ground faults to key nodes around the converter station and key nodes of the receiving-end network one by one. During the application of short-circuit faults and ground faults, the DC voltage recovery process, commutation failure record, and blocking trigger record are recorded synchronously at each fault location, and the fault type, fault node, and associated line are marked. The DC voltage recovery process, commutation failure record, and blocking trigger record together form the fault response record.

[0064] To further clarify, the key nodes around the converter station refer to the AC bus node of the converter station, the high-voltage side node of the converter transformer, the low-voltage side node of the converter transformer, the AC filter access node of the converter station, and the AC outgoing terminal node of the converter station.

[0065] Key nodes in the receiving-end network refer to the receiving-end AC bus node, receiving-end AC outgoing line node, receiving-end parallel reactive power compensation device access node, and adjacent substation bus node that is directly electrically connected to the inverter station AC bus.

[0066] The fault response record is used to determine the target fault. The occurrence of commutation failure record and blockage trigger record is used as the judgment event that the stable operation of the DC system is affected. The fault node and associated line corresponding to the judgment event are located. The fault node and associated line are summarized to form a target fault association list. The target fault association list is further summarized into a target object set, and the connecting branches that cross the target object set are marked to form a boundary connection marking table.

[0067] The target object set refers to the collection of converter station nodes, inverter station nodes, AC outgoing lines and lines within the target fault association list that are associated with the impact on the stable operation of the DC system.

[0068] The boundary connection label table extracts cross-set connection channels from the target object set. Dynamic phasor line corridor segments are configured for each cross-set connection channel, and a correspondence is established between the corridor port number, corridor port direction, and set boundary node for each dynamic phasor line corridor segment. The correspondence between the corridor port number, corridor port direction, and set boundary node is summarized to form a corridor port mapping table.

[0069] To further explain, the set boundary node refers to the bus node or line end node that is directly electrically connected to the external network on the set boundary of the converter station node, inverter station node, AC outgoing line and line corresponding to the target object set. The external network refers to the network composed of the remaining nodes and lines of the receiving-end AC system that are not included in the target object set.

[0070] The corridor port mapping table writes traveling wave propagation delay parameters and port equivalent impedance parameters for each dynamic phasor line corridor segment. The traveling wave propagation delay parameters are used to form traveling wave propagation delay isolation at the dynamic phasor traveling wave interface corridor to separate the large step size solution domain from the small step size solution domain. The port equivalent impedance parameters are used to form equivalent boundaries at the corridor ports to maintain the physical consistency of voltage and current exchange at the corridor ports. The traveling wave propagation delay parameters and port equivalent impedance parameters are summarized to form the interface corridor parameter file. After the interface corridor parameter file is output, it is used to write back to the target object set and lock the correspondence between the corridor ports and the set boundary nodes.

[0071] To further explain, the traveling wave propagation time delay parameter is determined by the following formula:

[0072] ;

[0073] in, This represents the propagation delay parameter of the traveling wave; This indicates the length of the line corresponding to the corridor segment of the dynamic phasor line. This indicates the propagation speed of the traveling wave along the line.

[0074] Furthermore, the propagation speed of a traveling wave is determined by the following formula:

[0075] ;

[0076] in, Indicates the inductance per unit length of the circuit; This represents the capacitance per unit length of the circuit.

[0077] The equivalent impedance parameter of the port is determined using the characteristic impedance of the line and by the following formula:

[0078] ;

[0079] in, This represents the equivalent impedance parameter of the port.

[0080] The interface corridor parameter file is written back to the target object set. The interface corridor parameter file and the corridor port mapping table together lock the correspondence between the corridor port and the set boundary node and solidify the corridor port connection direction of the cross-set communication channel. The correspondence between the corridor port and the set boundary node and the corridor port connection direction are summarized to form the boundary corridor binding list.

[0081] Extract the access relationships between the external network and the boundary node from the boundary corridor binding list, and perform equivalent access annotation on the connecting branches of the external network, and summarize them to form an external equivalent access table.

[0082] The target object set, interface corridor parameter file, and external equivalent access table are encapsulated and written with a version number and a consistency check identifier. The version number is used to identify the generation batch of the target object set configuration package, and the consistency check identifier is used to identify the combination consistency of the target object set, interface corridor parameter file, and external equivalent access table. The encapsulation result is output as the target object set configuration package.

[0083] The model building module constructs steady-state equivalent parameter models and transient equivalent parameter models according to the target object set configuration package in the electromagnetic transient simulation project, and assembles the steady-state equivalent parameter models and transient equivalent parameter models into a unified electromagnetic transient simulation project.

[0084] The target object set configuration package completes the loading of the electromagnetic transient simulation software, reads the target object set, interface corridor parameter file and external equivalent access table contained in the target object set configuration package, completes the topology positioning of the external equivalent access points marked in the external equivalent access table and the boundary connection channels marked in the target object set, writes the corridor port parameters marked in the interface corridor parameter file to the corresponding ports of the boundary connection channels, and completes the connection between the boundary corridor ports and the external equivalent access points and solidifies the connection relationship to form a unified topology project.

[0085] Within the unified topology project, the steady-state equivalent parameter models of surge arresters, DC filters, and wall bushings are built using a consistent connection method for the equipment ports. The equipment ports of the surge arrester steady-state equivalent parameter models are connected to the DC bus and grounding terminal, as are the equipment ports of the DC filter steady-state equivalent parameter models and the wall bushing steady-state equivalent parameter models. The connected steady-state equivalent parameter models of surge arresters, DC filters, and wall bushings are then combined to form a steady-state equipment model group.

[0086] The equivalent branch impedance of the steady-state equivalent parameter model of the DC filter is used for frequency domain consistency checking during steady-state initialization verification. The equivalent branch impedance is determined by the following formula:

[0087] ;

[0088] in, This represents the steady-state equivalent parameter model of a DC filter at angular frequency. Equivalent branch impedance at the location; The equivalent resistance represents the steady-state equivalent parameter model of a DC filter; The equivalent inductance represents the steady-state equivalent parameter model of a DC filter; The equivalent capacitance represents the steady-state equivalent parameter model of a DC filter; Represents the imaginary unit; It represents the angular frequency, used to identify the power frequency steady-state calculation frequency point corresponding to the steady-state initialization verification.

[0089] Steady-state initialization verification is performed on the steady-state equipment model group. The steady-state initialization verification completes the steady-state convergence check of the DC bus voltage, equipment port voltage and equipment port current of the unified topology project and solidifies the steady-state convergence state. The steady-state convergence state is summarized to form a steady-state initialization state set. The steady-state initialization state set is written back to the unified topology project and the parameters and connection relationships are solidified to form a steady-state equivalent parameter model.

[0090] Within the steady-state equipment model group, the transient model files for surge arresters, filters, and bushings are constructed. The surge arrester transient model file embeds the transient nonlinear conduction branch and energy absorption measurement channel within the port framework of the surge arrester steady-state equivalent parameter model. The filter transient model file embeds the transient high-frequency branch and damping branch within the port framework of the DC filter steady-state equivalent parameter model. The bushing transient model file embeds the transient ground capacitance network and surface leakage branch within the port framework of the through-wall bushing steady-state equivalent parameter model and reserves an equivalent parameter write-back interface. Specifically, the energy absorption measurement channel in the surge arrester transient model file uses port voltage and port current to calculate the surge arrester's energy absorption measurement results. The surge arrester's energy absorption measurement results are determined by the following formula and used for the measurement definition of the energy absorption measurement channel:

[0091] ;

[0092] in, Indicates time The corresponding surge arrester energy absorption measurement results; Indicates time The corresponding surge arrester port voltage; Indicates time The corresponding surge arrester port current; Represents the integration variable and is used to traverse transient processes; Indicates the cumulative termination time of the energy absorption measurement channel; It represents an integral infinitesimal element and is used to express the energy accumulation process.

[0093] The transient model files of surge arresters, filters, and bushings are solidified in parallel into a unified topology project according to the equipment port consistency rule, and the equipment port connection positions are kept the same as those of the steady-state equivalent parameter model. Lightning injection events, fault connection events, and switching events are configured with event entries in the unified topology project and a trigger mapping relationship is established with the transient model files of surge arresters, filters, and bushings, and a transient event mapping table is formed by summarizing them.

[0094] The transient event mapping table and the steady-state initialization state set are merged and solidified into a unified topology project. The transient event mapping table is used to limit the input path of the transient equivalent parameter model triggered by lightning injection events, fault input events and switching events. The steady-state initialization state set is used to limit the starting steady-state point of the transient equivalent parameter model. The merged and solidified results form the transient equivalent parameter model.

[0095] The steady-state equivalent parameter model and the transient equivalent parameter model are assembled in a unified topology project while keeping the connection relationship between the boundary corridor port and the equivalent access point outside the set unchanged. The output is a unified electromagnetic transient simulation project.

[0096] The solution exchange module performs real-time voltage and current exchange between the large-step solution domain and the small-step solution domain through the protocol conversion device and the communication link driving dynamic phasor traveling wave interface corridor, and performs multi-condition joint calculation in the unified electromagnetic transient simulation project to obtain multi-condition result packages.

[0097] In the unified electromagnetic transient simulation project, the location and reading of the corridor port mapping table and interface corridor parameter file are completed. The correspondence between the corridor port number, corridor port direction and set boundary node marked in the corridor port mapping table is completed to count the ports. The traveling wave propagation delay parameter and port equivalent impedance parameter marked in the interface corridor parameter file are verified. The port count results and parameter verification results are summarized to form a corridor port alignment table.

[0098] The first protocol conversion device reads the corridor port alignment table and writes the corridor port number and corridor port direction into the port configuration area. The port configuration area registers the channel for the small step size solution domain port voltage and current corresponding to the corridor port number and forms a port channel list. The port channel list and the corridor port alignment table are used together for communication frame field allocation.

[0099] The second protocol conversion device reads the corridor port alignment table and establishes a mapping relationship between the port and the communication frame field. The mapping relationship between the port and the communication frame field completes the port-by-port configuration of the voltage measurement field and current measurement field corresponding to the corridor port number and forms a communication frame mapping table. After the communication frame mapping table is output, it is used to solidify the transmit and receive format of the real-time exchange channel.

[0100] The first and second protocol conversion devices establish a real-time exchange channel through a communication link. The real-time exchange channel encapsulates the small-step solution domain port voltage and current according to the communication frame mapping table and sends it. At the same time, it parses the received large-step solution domain port voltage and current according to the communication frame mapping table and completes port restoration. The sending and receiving process and parsing process form a real-time exchange data stream.

[0101] The dynamic phasor traveling wave interface corridor performs port updates with propagation delay consistency on the real-time exchanged data stream based on the interface corridor parameter file. The port updates with propagation delay consistency apply the time delay alignment corresponding to the traveling wave propagation delay parameters to the corridor port voltage and corridor port current, and complete the port boundary consistency constraints according to the port equivalent impedance parameters. The output is the corridor boundary exchange state.

[0102] Among them, the corridor boundary exchange state is used to start the boundary exchange channel of the unified electromagnetic transient simulation project, and the steady-state initialization state set is used to solidify the starting steady-state point of the unified electromagnetic transient simulation project. The corridor boundary exchange state and the steady-state initialization state set together form the joint calculation starting state.

[0103] In the initial state of the joint calculation, lightning injection events are applied according to the same event sequence. The lightning injection events act on the DC bus and trigger the transient event mapping table to input the corresponding transient sub-model. The DC bus voltage, equipment port voltage and equipment port current are recorded, and the surge arrester energy absorption measurement channel is recorded, forming a lightning strike operating condition waveform record.

[0104] The same event sequence corresponding to the lightning strike waveform record is used to continue to input short-circuit ground fault events. The short-circuit ground fault event restores the fault branch according to the preset clearing strategy and triggers the transient event mapping table to input the corresponding transient sub-model. The input and clearing process records the DC bus voltage, equipment port voltage and equipment port current and filter branch current. The recording results form the ground fault waveform record.

[0105] To further explain, the pre-set clearing strategy refers to the clearing strategy that pre-fixes the fault duration in the short-circuit ground fault event entry according to the fault initiation time and fault type, and performs the fault branch disconnection to restore the normal connection state of the fault branch when the duration is reached.

[0106] The same event sequence corresponding to the ground fault waveform record continues to apply switching events. The switching event triggers the transient event mapping table to input the corresponding transient sub-model and records the DC bus voltage, equipment port voltage and equipment port current. The recording results form the switching overvoltage waveform record.

[0107] The same event sequence corresponding to the waveform record of the switching overvoltage condition completes the configuration of the severe weather boundary condition group for the external insulation of the bushing through the wall in the finite element simulation software. The equivalent capacitance and equivalent leakage conductance of the external insulation of the bushing through the wall are obtained from the severe weather boundary condition group. The equivalent capacitance and equivalent leakage conductance are written into the surface leakage branch and the transient ground capacitance network through the equivalent parameter write-back interface of the bushing transient model file and form a severe weather parameter write-back record.

[0108] To further clarify, the severe weather boundary condition set for the external insulation of the wall bushing refers to the set of rain, fog, and pollution boundary conditions and icing boundary conditions applied to the external insulation surface of the wall bushing in the finite element simulation software.

[0109] The steps to obtain the equivalent capacitance and equivalent leakage conductance are as follows: Import the geometry of the external insulation of the through-wall bushing into the finite element simulation software and write the dielectric constant and conductivity parameters of the external insulation. Then, divide the surface of the external insulation into a mesh and set the conductor boundaries as the potential ends of the conductor and the grounding end of the through-wall bushing. Next, define rain, fog, and contamination boundary conditions on the external insulation surface, write the equivalent surface conductivity parameters of the wet conductive layer, and set the coverage area of ​​the conductive layer. Finally, define icing boundary conditions on the external insulation surface, write the icing layer thickness and icing dielectric constant parameters, and set the icing layer coverage area.

[0110] The finite element simulation software performs electrostatic field solutions for rain, fog, pollution boundary conditions and icing boundary conditions, and outputs the total charge at the potential end of the through-wall bushing conductor and the leakage current at the grounding end. The equivalent capacitance is calculated by the ratio of the total charge to the applied potential difference and is recorded as the equivalent capacitance. The equivalent leakage conductance is calculated by the ratio of the leakage current to the applied potential difference and is recorded as the equivalent leakage conductance. The equivalent capacitance and equivalent leakage conductance are written into the transient ground capacitance network and surface leakage branch through the equivalent parameter write-back interface of the bushing transient model file and form a severe weather parameter write-back record.

[0111] The waveform records for lightning strike conditions, ground fault conditions, switching overvoltage conditions, and severe weather parameter write-back records are encapsulated by device port index and event sequence index, and the output is a multi-condition result package.

[0112] The result verification module performs a comparison between normal and special operating conditions on the multi-condition result package, completes the verification of insulation status and electrical stress, and performs recalculation verification, and outputs a verification evaluation report.

[0113] The waveform records for lightning strike, ground fault, and switching overvoltage conditions, as well as the write-back records of severe weather parameters, are extracted from the multi-condition result package. The steady-state time windows before the event triggering time are extracted from the waveform records for lightning strike, ground fault, and switching overvoltage conditions and summarized to form a steady-state record for normal operation. The steady-state record for normal operation is then aligned with the waveform records for lightning strike, ground fault, and switching overvoltage conditions according to the DC bus voltage, equipment port voltage, and equipment port current of the steady-state initialization state set for timestamp and amplitude reference alignment, forming an aligned waveform set.

[0114] The aligned waveform set is used to generate a device-by-device, condition-by-condition comparison page based on the device port index and event sequence index. The port overvoltage characteristics and wavefront steepness characteristics are calculated on the device-by-device, condition-by-condition comparison page and written into the feature field of the page.

[0115] The port overvoltage characteristic is calculated using the device port voltage of the aligned waveform set, and the expression is:

[0116] ;

[0117] in, Indicates port overvoltage characteristics; This represents the change in the device port voltage over time for the corresponding operating condition within the aligned waveform set. Represents a time variable; This indicates the feature extraction time window defined by the event sequence index; This indicates the maximum value operation; the wavefront steepness feature is calculated using the device port voltage of the aligned waveform set and satisfies...

[0118] ;

[0119] in, Indicates the steepness of the wavefront; This represents the rate of change of the device port voltage with respect to time. This indicates the absolute value operation;

[0120] The comparison pages for each device and each operating condition, along with the port overvoltage characteristics and wavefront steepness characteristics, are summarized to form a set of operating condition comparison pages.

[0121] Extract the surge arrester energy absorption records, port voltage stress records, and filter branch current records from the working condition comparison page set, and associate the equivalent capacitance and equivalent leakage conductance with the adverse weather parameter write-back records according to the wall bushing equipment index to form an electrical stress verification table.

[0122] Based on the severe weather parameters, the location of the hot spot of external insulation field strength output by the finite element simulation software is recorded and written into the index field of the wall bushing equipment. The location of the hot spot of external insulation field strength is matched with the electrical stress verification table according to the index of the wall bushing equipment and summarized to form an insulation verification record table.

[0123] The electrical stress verification table and insulation verification record table are summarized to form a verification conclusion, which is then written into the reliability improvement measures group. The reliability improvement measures group includes adjustments to the surge arrester energy level and layout, setting of DC filter damping branch parameters and switching sequence, and configuration of wall bushing equalization and anti-pollution structure. The verification conclusion is called while keeping the corridor port mapping table, interface corridor parameter file, and external equivalent access table unchanged. The same event sequence is reproduced in the unified electromagnetic transient simulation project, and the recalculation result package is repackaged and output. The recalculation result package and the multi-condition result package are compared according to the equipment port index and event sequence index. Specifically:

[0124] The waveforms in the recalculated result package are compared with those in the original multi-condition result package based on the device port index and event sequence index. The comparison focuses on key parameters such as device port voltage, device port current, and filter branch current. The comparison process includes changes in waveform morphology, amplitude, and characteristic points. If the key parameters of the waveforms in the recalculated result package and the original multi-condition result package show consistent changes under the same event sequence, it indicates that the reliability improvement measures have been effective and the differences meet the predetermined targets. The verification conclusion is then confirmed as valid and recorded in the difference comparison results. If the waveform morphology, amplitude, or characteristic points do not change, it indicates that the existing reliability improvement measures have not produced any improvement effect. During the comparison process, if there are unexpected changes between the recalculated result package and the original multi-condition result package, the relevant adjustment measures will be further improved in the verification conclusion, and the effectiveness of the measures will be recalculated and verified until the differences between the relevant waveforms in the recalculated result package and the original multi-condition result package meet the predetermined targets. The verification conclusions and difference comparison records are then summarized and output as a verification evaluation report.

[0125] To further explain, the predetermined target refers to the expected improvement in electrical stress and insulation condition after implementing reliability enhancement measures. It is pre-set during the scheme design phase through analysis, experience, and relevant standards and specifications, aiming to improve the reliability and safety of DC equipment and ensure its stable operation under various operating conditions.

[0126] The expected changes are the actual improvements that should occur in terms of waveform shape, amplitude, and characteristic points during the comparison process, while the predetermined target is a more specific and quantifiable expected result. The expected changes are to verify whether the predetermined target has been achieved.

[0127] In summary, this invention performs short-circuit and ground fault scanning within the electromechanical transient baseline engineering of AC / DC systems using a fault scanning module, generating a target object set and a boundary connection annotation table. This allows subsequent electromagnetic transient simulation engineering to model only the converter station nodes, inverter station nodes, AC outgoing lines, and lines involved in the target fault association list, reducing the modeling scope and configuration complexity of multi-condition joint calculations. By deploying dynamic phasor traveling wave interface corridors in the boundary connection channels and writing traveling wave propagation delay parameters and port equivalent impedance parameters, consistent port updates and equivalent boundary constraints with propagation delays are achieved, improving the performance of large step sizes. Physical consistency of real-time voltage and current exchange between the solution domain and the small-step solution domain; assembly of steady-state equivalent parameter models and transient equivalent parameter models into a unified electromagnetic transient simulation project within a unified topology project, and unified management of the triggering paths of lightning injection events, fault input events, and switching events using a transient event mapping table to improve the consistency of event sequences in multi-condition result packages; formation of verification conclusions and reproduction of the same event sequence through the linkage of aligned waveform sets, operating condition comparison page sets, electrical stress verification base tables, and insulation verification record tables, so that the verification evaluation report has repeatable difference comparison basis.

[0128] Example 2, referring to Table 1, is the second embodiment of the present invention. To further verify the technical solution of the present invention, experimental simulation data of the multi-condition simulation modeling and analysis system for DC equipment in converter stations are given.

[0129] A ±500kV DC transmission project with a rated power of 2000MW was selected as the test scenario. The electromechanical transient baseline engineering of the AC / DC system was incorporated into the operating mode parameter set and fault application rule set. The operating mode parameter set defined the topology closing status and power flow support mode of converter station nodes, inverter station nodes, AC outgoing lines, and transmission lines. The fault application rule set defined the fault types, fault location methods, and fault duration configuration methods for short-circuit faults and ground faults. The operating mode parameter set and fault application rule set together formed the baseline operating rule table. The baseline operating rule table applied short-circuit faults and ground faults to key nodes around the converter station and key nodes of the receiving-end network one by one, generating fault response records and recording the DC voltage recovery process, commutation failure records, and blocking trigger records. Target fault determination used the occurrence of commutation failure records and blocking trigger records as events affecting the stable operation of the DC system. The fault nodes and associated lines corresponding to the determined events were located and summarized to form a target fault association list. The target fault association list was further summarized to form a draft target object set and generate a boundary connection labeling table. The boundary connection labeling table configures dynamic phasor line corridor segments for each cross-set connection channel, establishes a corridor port mapping table and writes it into the interface corridor parameter file. After the interface corridor parameter file is written back to the initial draft of the target object set, the boundary corridor binding list and the external equivalent access table are solidified, and the target object set configuration package is encapsulated and output.

[0130] After the target object set configuration package is loaded into the electromagnetic transient simulation software, a unified topology project is built: Based on the external equivalent access table, connect the equivalent access points outside the set; based on the interface corridor parameter file and corridor port mapping table, write the corridor port parameters and connect the boundary corridor ports; within the unified topology project, build the steady-state equivalent parameter models of surge arresters, DC filters, and bushings according to the consistent connection method of the device ports, forming a steady-state device model group; complete the steady-state initialization verification and generate a steady-state initialization state set; after the steady-state initialization state set is written back to the unified topology project, a steady-state equivalent parameter model is formed; subsequently, within the port framework of the steady-state device model group, construct transient model files for surge arresters, filters, and bushings; these three types of transient model files are solidified in parallel into the unified topology project to form a transient event mapping table; the transient event mapping table and the steady-state initialization state set are solidified to form a transient equivalent parameter model; the steady-state equivalent parameter model and the transient equivalent parameter model are assembled and output as a unified electromagnetic transient simulation project.

[0131] After the unified electromagnetic transient simulation project completes the location reading of the corridor port mapping table and interface corridor parameter file, a corridor port alignment table is formed. The first and second protocol conversion devices form a communication frame mapping table based on the corridor port alignment table and establish a real-time exchange channel through the communication link. The dynamic phasor traveling wave interface corridor performs port updates with consistent propagation delay on the real-time exchange data stream and outputs the corridor boundary exchange state. The corridor boundary exchange state and the steady-state initialization state set together form the joint calculation start state. The joint calculation start state executes the lightning injection event, short-circuit ground fault event, and switching event in the same event sequence, and generates the lightning strike waveform record, ground fault waveform record, and switching overvoltage waveform record, respectively. The finite element simulation software obtains the equivalent capacitance and equivalent leakage conductance under the severe weather boundary condition group of the external insulation of the through-wall bushing and generates severe weather parameter write-back records through the bushing transient model file write-back interface. The three types of waveform records and severe weather parameter write-back records are encapsulated and output as multi-condition result packages according to the device port index and event sequence index. During the result verification phase, an aligned waveform set is formed from the multi-condition result package, and a set of condition comparison pages is generated. This is further used to form an electrical stress verification base table and an insulation verification record table, which are then summarized to form a verification conclusion. After the verification conclusion is written into the reliability improvement measures group, the corridor port mapping table, interface corridor parameter file, and external equivalent access table are kept unchanged. The same event sequence is reproduced to generate a recalculation result package. The recalculation result package and the multi-condition result package are compared according to the equipment port index and the event sequence index, and a verification evaluation report is output.

[0132] The details are shown in Table 1 below:

[0133] Table 1. Comparison Data of Multi-condition Joint Calculation

[0134] Parameters\Object This invention - Corridor Linkage Calculation (Automatic Object Set) Comparison with A-Network EMT small step size (benchmark) Compare with B-static external equivalent (no traveling wave delay) Comparison of C-corridor joint calculation (artificial object set) This invention - Corridor interconnection calculation (ice-covered write-back) Compare with D-static external equivalents (icing without writeback). Number of nodes in the target object set 420 1850 220 560 420 220 Number of equivalent access points outside the set (number) 16 0 16 16 16 16 Number of corridor ports for dynamic phasor traveling wave interface (number) 32 0 0 32 32 0 Small step size solution domain step size (µs) 10 10 10 10 10 10 Large step size solution domain step size (ms) 2 NA NA 2 2 NA Time taken for a single multi-condition joint calculation (min) 32 180 18 40 34 19 DC bus port overvoltage peak error (%) 1.8 0 12.5 2.4 2 14.2 Traveling wave arrival time deviation (µs) 7 0 90 11 8 120 Consistency rate of commutation failure judgment (%) 98.5 100 82 94 98 78 Surge arrester energy absorption measurement deviation (%) 2.1 0 15.3 3.4 2.3 17 Consistency rate (%) of external insulation field strength hotspots in wall bushings 95 100 70 88 96 65 Recalculate the number of iterations (times). 1 0 3 2 1 3 Multi-condition results package size (MB) 85 310 52 102 90 55

[0135] The relationship between computational scale and computational cost can be obtained from the "number of nodes in the target object set" and "time for a single multi-condition joint calculation (min)". Compared with the A-full network EMT small step size (baseline) of 1850 nodes and 180 min, the present invention-corridor joint calculation (automatic object set) of 420 nodes and 32 min, while maintaining the solution domain step size of 10µs, the multi-condition joint calculation time is reduced from 180 min to 32 min by using the initial draft of the target object set and the boundary organization method of the dynamic phasor traveling wave interface corridor. At the same time, the size of the multi-condition result package is reduced from 310MB to 85MB, which reflects the direct reduction in data management and computational resource consumption. Compared with the C-corridor joint calculation (manual object set) which takes 40 min and has 560 nodes, it shows that the automatic object set selection has a quantifiable advantage in reducing the solution scale.

[0136] The impact of boundary delay consistency on transient accuracy can be obtained from the "DC bus port overvoltage peak error (%)" and "traveling wave arrival time deviation (µs)". The DC bus port overvoltage peak error of this invention-corridor linkage (automatic object set) is 1.8%, and the traveling wave arrival time deviation is 7µs. In contrast, the DC bus port overvoltage peak error of B-static external equivalent (no traveling wave delay) is 12.5%, and the traveling wave arrival time deviation is 90µs. Compared to D-static external equivalent (ice-covered without write-back), the traveling wave arrival time deviation further increases to 120µs. This indicates that static external equivalent, lacking traveling wave propagation delay constraints, struggles to maintain physical consistency of boundary voltage and current exchange, leading to measurable deviations in overvoltage peak value and arrival time. In contrast, C-corridor linkage (artificial object set), even with the same number of corridor ports, still exhibits a traveling wave arrival time deviation of 11µs, reflecting that insufficient selection of the object set boundary affects the port alignment effect through the combination of boundary port positions and external equivalent access points.

[0137] From the consistency rate of commutation failure judgment (%), the deviation of surge arrester energy absorption measurement (%), and the consistency rate of hot spot corresponding to external insulation field strength of wall bushing (%), we can obtain the cross-toolchain consistency and recalculation closed-loop capability: the consistency rate of commutation failure judgment of this invention-corridor joint calculation (automatic object set) is 98.5%, the deviation of surge arrester energy absorption measurement is 2.1%, and the consistency rate of hot spot corresponding to external insulation field strength of wall bushing is 95.0%; compared with B-static external equivalent (no traveling wave delay) are 82.0% / 15.3% / 70.0%, respectively, indicating that in the multi-condition joint calculation and verification link, the dynamic phasor traveling wave interface corridor and the bushing transient model file equivalent parameter write-back interface jointly support the closed loop of "event sequence consistency, boundary quantity consistency, parameter write-back consistency", reducing the number of recalculation iterations to 1 (compared to 3 times for B), thus demonstrating the verifiability and convergence of the reliability improvement measures group at the engineering implementation level.

[0138] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A multi-condition simulation modeling and analysis system for DC equipment in a converter station, characterized in that: include, The fault scanning module performs short-circuit and ground fault scanning in the electromechanical transient baseline engineering of AC / DC systems, deploys dynamic phasor traveling wave interface corridors in the boundary communication channels of the target object set, and outputs the target object set configuration package. The model building module constructs steady-state equivalent parameter models and transient equivalent parameter models according to the target object set configuration package in the electromagnetic transient simulation project, and assembles the steady-state equivalent parameter models and transient equivalent parameter models into a unified electromagnetic transient simulation project; The solution exchange module performs real-time voltage and current exchange between the large-step solution domain and the small-step solution domain through the protocol conversion device and the communication link driving the dynamic phasor traveling wave interface corridor, and performs multi-condition joint calculation in the unified electromagnetic transient simulation project to obtain multi-condition result packages; The result verification module performs a comparison between normal and special operating conditions on the multi-condition result package, completes the verification of insulation status and electrical stress, and performs recalculation verification, and outputs a verification evaluation report.

2. The multi-condition simulation modeling and analysis system for converter station DC equipment as described in claim 1, characterized in that: The execution of short-circuit and ground fault scanning specifically involves: The simulation center establishes an electromechanical transient baseline project for AC / DC systems and writes it into the operating mode parameter set and fault application rule set, generating a baseline operating rule table; Short-circuit faults and ground faults are applied to key nodes around the converter station and key nodes of the receiving-end network according to the baseline operation rule table, and fault response records are generated. Perform target fault determination on the fault response record, extract the nodes and lines involved in the fault that triggered the determination, generate a target fault association list, summarize the target fault association list and mark the external connection branches, and generate a target object set and boundary connection label table.

3. The multi-condition simulation modeling and analysis system for converter station DC equipment as described in claim 1, characterized in that: The target object set refers to the collection of converter station nodes, inverter station nodes, AC outgoing lines and lines within the target fault association list that are associated with the impact on the stable operation of the DC system.

4. The multi-condition simulation modeling and analysis system for converter station DC equipment as described in claim 1, characterized in that: The output target object set configuration package is specifically: Based on the boundary connection labeling table, cross-set connection channels are extracted from the target object set, and dynamic phasor line corridor segments are established for each connection channel, generating a corridor port mapping table. Based on the corridor port mapping table, write the traveling wave propagation delay parameters and port equivalent impedance parameters for each corridor segment to generate an interface corridor parameter file; Write the interface corridor parameter file back to the target object set, lock the correspondence between the corridor port and the set boundary node, and generate the boundary corridor binding list; Extract the access relationships between the external network and the boundary nodes from the boundary corridor binding list, and generate an external equivalent access table; The target object set, interface corridor parameter file, and external equivalent access table are encapsulated, and a version number and consistency verification identifier are written into them, and the target object set configuration package is output.

5. The multi-condition simulation modeling and analysis system for converter station DC equipment as described in claim 1, characterized in that: The construction of the steady-state equivalent parameter model specifically involves: In the electromagnetic transient simulation software, a target object set electromagnetic transient simulation project is established, and the target object set configuration package is loaded to complete the connection between the boundary corridor port and the equivalent access point outside the set, generating a unified topology project; Within a unified topology project, each device port is connected to the DC bus and grounding terminal using a consistent connection method to generate a steady-state device model group. Perform steady-state initialization verification on the steady-state device model group, generate a steady-state initialization state set, write the steady-state initialization state set into the unified topology project, and generate a steady-state equivalent parameter model.

6. The multi-condition simulation modeling and analysis system for converter station DC equipment as described in claim 1, characterized in that: The construction of the transient equivalent parameter model is as follows: Within the steady-state equipment model group, the transient nonlinear conduction branch and energy absorption measurement channel of the surge arrester are solidified, and the transient model file of the surge arrester is generated; the transient high-frequency branch and damping branch of the DC filter are solidified, and the transient model file of the filter is generated; the transient ground capacitance network and surface leakage branch of the through-wall bushing are solidified and an equivalent parameter write-back interface is reserved, and the bushing transient model file is generated. The transient model files of surge arresters, filters, and bushings are solidified into a unified topology project in parallel according to the equipment port consistency rules, and the trigger mappings of lightning injection events, fault connection events, and switching events are written to generate a transient event mapping table. Merge the transient event mapping table with the steady-state initialization state set to output the transient equivalent parameter model.

7. The multi-condition simulation modeling and analysis system for converter station DC equipment as described in claim 1, characterized in that: The real-time voltage and current exchange between the large-step solution domain and the small-step solution domain specifically involves: The first protocol conversion device reads the interface corridor parameter file and corridor port mapping table from the target object set configuration package and generates a corridor port alignment table. The second protocol conversion device reads the corridor port alignment table and establishes a mapping relationship between ports and communication frame fields, generating a communication frame mapping table; The first protocol conversion device and the second protocol conversion device establish a real-time exchange channel through a communication link, send small-step solution domain port voltage and current according to the communication frame mapping table, and receive large-step solution domain port voltage and current to generate a real-time exchange data stream; The dynamic phasor traveling wave interface corridor performs port updates with consistent propagation delay on the real-time exchanged data stream based on the interface corridor parameter file, and outputs the corridor boundary exchange status.

8. The multi-condition simulation modeling and analysis system for converter station DC equipment as described in claim 1, characterized in that: The process of performing multi-condition joint calculations in the unified electromagnetic transient simulation project is as follows: Invoke the corridor boundary exchange state to start the unified electromagnetic transient simulation project, load the steady-state initialization state set, and generate the joint calculation start state; Based on the initial state of the joint calculation, lightning injection events are applied to the DC bus according to the same event sequence, and the transient event mapping table is triggered to input the corresponding transient sub-model to generate lightning strike waveform records. Short-circuit ground fault events are initiated according to the same event sequence, and the fault branch is restored according to the preset clearing strategy. At the same time, the transient event mapping table is triggered to initiate the corresponding transient sub-model and generate ground fault operating condition waveform records. Apply switching events according to the same event sequence, and trigger the transient event mapping table to input the corresponding transient sub-model to generate switching overvoltage condition waveform records; In the finite element simulation software, a set of severe weather boundary conditions for the external insulation of the through-wall bushing is established, and the equivalent capacitance and equivalent leakage conductance are obtained. At the same time, the surface leakage branch and capacitance network are updated through the write-back interface of the bushing transient model file, and a severe weather parameter write-back record is generated. The waveform records of lightning strike, ground fault, switching overvoltage, and severe weather parameters are encapsulated according to the device port index and event sequence index, and the multi-condition result package is output.

9. The multi-condition simulation modeling and analysis system for converter station DC equipment as described in claim 1, characterized in that: The comparison of normal and special operating conditions for the multi-condition result package is performed as follows: Extract the steady-state records of normal operating conditions and the waveform records of special operating conditions from the multi-condition result package, and align the time axis according to the steady-state initialization state set to generate an aligned waveform set; Based on the device port index, generate a device-by-device, condition-by-condition comparison page within the aligned waveform set, and annotate the port overvoltage characteristics, wavefront steepness characteristics, and filter branch current characteristics to generate a set of condition comparison pages.

10. The multi-condition simulation modeling and analysis system for converter station DC equipment as described in claim 1, characterized in that: The completion of insulation status and electrical stress verification and recalculation verification specifically includes: Extract surge arrester energy absorption records, port voltage stress records, and filter branch current records from the working condition comparison page set, and combine them with severe weather parameter write-back records to generate an electrical stress verification table. The locations of hot spots of external insulation field strength output from finite element simulation are matched with the electrical stress verification table according to the wall bushing equipment index to generate an insulation verification record table; Summarize the electrical stress verification table and insulation verification record table to form a verification conclusion; Calling the verification conclusion, the same event sequence is reproduced in the unified electromagnetic transient simulation project, the multi-condition result package is regenerated and the aligned waveform set is updated to generate the recalculation result package; The recalculated result package is compared with the original multi-condition result package, and a verification and evaluation report is output.

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