Overvoltage electromagnetic transient simulation method and device in alternating current power transmission and transformation system

Abstract

The embodiment of the invention provides an overvoltage electromagnetic transient simulation method and device in an alternating current power transmission and transformation system. The method comprises the following steps: determining calculation data based on a power grid condition; determining a system equivalence point based on the calculation boundary and the calculation mode, and determining an equivalence calculation result; determining an electromagnetic transient simulation basic model based on the system equivalence point and the calculation boundary; generating a system electromagnetic transient simulation model based on the electromagnetic transient simulation basic model and the equivalent calculation result; determining an internal overvoltage calculation item, and selecting an item function module based on the internal overvoltage calculation item; determining a target electromagnetic transient simulation model based on the project function module and the system electromagnetic transient simulation model; and determining an efficient simulation calculation module based on the internal overvoltage calculation item, and performing simulation calculation based on the target electromagnetic transient simulation model and the efficient simulation calculation module to determine a simulation result. Modularization, controllability and process of internal overvoltage calculation are achieved, calculation efficiency and accuracy can be improved, and time and labor cost are saved.

Description

Technical Field

[0001] The embodiments of this specification relate to the field of insulation protection technology, and in particular to a method for simulating overvoltage electromagnetic transients in an AC power transmission and transformation system. Background Art

[0002] Internal overvoltage calculation is of great significance to the ultra-high voltage transmission and transformation system. It is an important technical basis for overvoltage and insulation protection during the startup, commissioning and operation of the project. It can be used to verify whether the infrastructure design of the transmission and transformation project is reasonable, whether the project can be started normally and put into operation safely, and whether the overvoltage and insulation coordination are matched under normal and various maintenance methods after the project is started and put into operation. At the same time, it can also provide simulation analysis methods for the startup, operation and accident analysis of the power system infrastructure of the power grid.

[0003] At present, the calculation work is mainly carried out in China based on the electromagnetic transient simulation software PSCAD / TMTDC. The related research mainly combines the actual engineering to carry out the mechanism analysis, influencing factor analysis, and actual engineering problems and solutions in terms of power frequency overvoltage, operation overvoltage, sub-supply current and recovery voltage. There is no publicly published research on internal overvoltage simulation calculation technology and related efficiency improvement. With the accelerated development of the power grid, new energy sources are connected to the power grid at an exponential rate, and the operation mode of the power grid is becoming more and more complex. The demand for internal overvoltage calculation of power grid projects is increasing and becoming more and more important, which puts higher requirements on calculation efficiency and accuracy. Therefore, a better solution is urgently needed. Summary of the invention

[0004] In view of this, the embodiments of this specification provide a method for simulating overvoltage electromagnetic transients in an AC power transmission and transformation system. One or more embodiments of this specification also involve an apparatus for simulating overvoltage electromagnetic transients in an AC power transmission and transformation system, a computing device, a computer-readable storage medium, and a computer program to solve the technical defects existing in the prior art.

[0005] According to a first aspect of an embodiment of this specification, there is provided a method for simulating an overvoltage electromagnetic transient state in an AC power transmission and transformation system, comprising: Determine the power grid conditions, and determine calculation data based on the power grid conditions; wherein the calculation data includes a calculation boundary and a calculation method; Determine the system equivalent points based on the calculation boundary and calculation method, and determine the equivalent calculation results; Determine the basic model of electromagnetic transient simulation based on system equivalent points and calculation boundaries; Generate a system electromagnetic transient simulation model based on the electromagnetic transient simulation basic model and equivalent calculation results; Determine the internal overvoltage calculation project, and select the project function module based on the internal overvoltage calculation project; Determine the target electromagnetic transient simulation model based on the project functional modules and the system electromagnetic transient simulation model; Based on the internal overvoltage calculation project, an efficient simulation calculation module is determined, and simulation calculation is performed based on the target electromagnetic transient simulation model and the efficient simulation calculation module to determine the simulation results.

[0006] In a possible implementation, determining the calculation data based on the power grid situation includes: Determine a calculation object, and determine a related object based on the calculation object; wherein the calculation object and the related object include a substation and a transmission line; Determine a computation boundary based on the computation object and related objects; Determine the commissioning method and maintenance method, and determine the calculation method based on the commissioning method and maintenance method.

[0007] In a possible implementation, the basic model of electromagnetic transient simulation is determined based on the system equivalent points and the calculation boundary, including: Determine the voltage source model and the impedance model, and determine the equivalent power source model, the self-impedance model and the mutual impedance model based on the system equivalent point, the voltage source model and the impedance model; Determine the Bergeron model based on the calculation boundary and establish the frequency phase domain model corresponding to the calculation object; The basic model of electromagnetic transient simulation is determined based on the equivalent power supply model, self-impedance model, mutual impedance model, Bergeron model and frequency phase domain model.

[0008] In a possible implementation, a system electromagnetic transient simulation model is generated based on the electromagnetic transient simulation basic model and the equivalent calculation result, including: Determine the calculation model based on the equivalent calculation results and the basic model of electromagnetic transient simulation; Determine the simulation results of the case model, compare the simulation results with the power flow results, and generate a system electromagnetic transient simulation model.

[0009] In a possible implementation, determining a target electromagnetic transient simulation model based on a project functional module and a system electromagnetic transient simulation model includes: The system electromagnetic transient simulation model is added based on the project function module, and the electrical node name of the project function module is set to the same node name as the calculation object to obtain the target electromagnetic transient simulation model.

[0010] In a possible implementation, simulation calculation is performed based on a target electromagnetic transient simulation model and an efficient simulation calculation module to determine a simulation result, including: The action timing realization is determined based on the efficient simulation calculation module, and the simulation calculation is performed based on the action timing realization and the target electromagnetic transient simulation model to determine the simulation result.

[0011] In a possible implementation, the method further includes: Analyze and process the simulation results to determine the analysis results; The analysis results are formatted and the analysis report is determined.

[0012] According to a second aspect of the embodiments of this specification, there is provided an overvoltage electromagnetic transient simulation device in an AC power transmission and transformation system, comprising: A data determination module is configured to determine a power grid condition and determine calculation data based on the power grid condition; wherein the calculation data includes a calculation boundary and a calculation method; An equivalent point determination module is configured to determine the equivalent point of the system based on the calculation boundary and the calculation method, and determine the equivalent calculation result; A basic model determination module is configured to determine a basic model for electromagnetic transient simulation based on system equivalent points and calculation boundaries; A transient model determination module is configured to generate a system electromagnetic transient simulation model based on an electromagnetic transient simulation basic model and an equivalent calculation result; A calculation item determination module is configured to determine an internal overvoltage calculation item and select an item function module based on the internal overvoltage calculation item; a target model determination module configured to determine an internal overvoltage calculation item and select a project function module based on the internal overvoltage calculation item; The simulation calculation module is configured to determine the high-efficiency simulation calculation module based on the internal overvoltage calculation project, and perform simulation calculation based on the target electromagnetic transient simulation model and the high-efficiency simulation calculation module to determine the simulation result.

[0013] According to a third aspect of an embodiment of this specification, a computing device is provided, including: Memory and processor; The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the above-mentioned overvoltage electromagnetic transient simulation method in the AC power transmission and transformation system are implemented.

[0014] According to a fourth aspect of the embodiments of this specification, a computer-readable storage medium is provided, which stores computer-executable instructions, which, when executed by a processor, implement the steps of the above-mentioned method for simulating overvoltage electromagnetic transients in an AC power transmission and transformation system.

[0015] According to a fifth aspect of the embodiments of this specification, a computer program is provided, wherein when the computer program is executed in a computer, the computer is caused to execute the steps of the above-mentioned method for simulating overvoltage electromagnetic transients in an AC power transmission and transformation system.

[0016] The embodiments of this specification provide a method and device for simulating electromagnetic transient overvoltage in an AC power transmission and transformation system, including: determining calculation data based on power grid conditions; determining system equivalent points based on calculation boundaries and calculation methods, and determining equivalent calculation results; determining electromagnetic transient simulation basic models based on system equivalent points and calculation boundaries; generating system electromagnetic transient simulation models based on electromagnetic transient simulation basic models and equivalent calculation results; determining internal overvoltage calculation projects, and selecting project function modules based on internal overvoltage calculation projects; determining target electromagnetic transient simulation models based on project function modules and system electromagnetic transient simulation models; determining efficient simulation calculation modules based on internal overvoltage calculation projects, and performing simulation calculations based on target electromagnetic transient simulation models and efficient simulation calculation modules, and determining simulation results. The modularization, controllability and process-based nature of internal overvoltage calculations are achieved, which can improve calculation efficiency and accuracy, and save time and labor costs. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 It is a flow chart of an overvoltage electromagnetic transient simulation method in an AC power transmission and transformation system provided by an embodiment of this specification; Figure 2 It is a schematic diagram of equivalent points of an overvoltage electromagnetic transient simulation method in an AC power transmission and transformation system provided by an embodiment of this specification; Figure 3 It is a schematic diagram of a basic model of electromagnetic transient simulation of an overvoltage electromagnetic transient simulation method in an AC power transmission and transformation system provided by an embodiment of this specification; Figure 4 It is a schematic diagram of a calculation model of an overvoltage electromagnetic transient simulation method in an AC power transmission and transformation system provided by an embodiment of this specification; Figure 5 It is a schematic diagram of a general model library for internal overvoltage calculation of an AC power transmission and transformation system internal overvoltage electromagnetic transient simulation method provided by an embodiment of this specification; Figure 6a It is a schematic diagram of a power frequency overvoltage calculation module of an overvoltage electromagnetic transient simulation method in an AC power transmission and transformation system provided by an embodiment of this specification; Figure 6b It is a schematic diagram of a result display module of an overvoltage electromagnetic transient simulation method in an AC power transmission and transformation system provided by an embodiment of this specification; Figure 6c It is a waveform diagram of an overvoltage electromagnetic transient simulation method in an AC power transmission and transformation system provided by an embodiment of this specification; Figure 7 It is a schematic diagram of efficient simulation calculation of internal overvoltage of an AC power transmission and transformation system internal overvoltage electromagnetic transient simulation method provided by one embodiment of this specification; Figure 8It is a structural schematic diagram of an overvoltage electromagnetic transient simulation device in an AC power transmission and transformation system provided by an embodiment of this specification; Fig. 9 It is a structural block diagram of a computing device provided by an embodiment of this specification. DETAILED DESCRIPTION

[0017] Many specific details are described in the following description to facilitate a full understanding of this specification. However, this specification can be implemented in many other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of this specification, so this specification is not limited to the specific implementation disclosed below.

[0018] The terms used in one or more embodiments of this specification are only for the purpose of describing specific embodiments, and are not intended to limit one or more embodiments of this specification. The singular forms of "a" and "the" used in one or more embodiments of this specification and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in one or more embodiments of this specification refers to and includes any or all possible combinations of one or more associated listed items.

[0019] It should be understood that although the terms first, second, etc. may be used to describe various information in one or more embodiments of this specification, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of one or more embodiments of this specification, the first may also be referred to as the second, and similarly, the second may also be referred to as the first. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0020] In this specification, a method for simulating overvoltage electromagnetic transients in an AC power transmission and transformation system is provided. This specification also involves an apparatus for simulating overvoltage electromagnetic transients in an AC power transmission and transformation system, a computing device, and a computer-readable storage medium, which are described in detail one by one in the following embodiments.

[0021] See also Figure 1 , Figure 1 A flow chart of an overvoltage electromagnetic transient simulation method in an AC power transmission and transformation system provided according to an embodiment of the present specification is shown, which specifically includes the following steps.

[0022] Step 101: Determine the power grid situation, and determine calculation data based on the power grid situation; wherein the calculation data includes a calculation boundary and a calculation method.

[0023] In one possible implementation, calculation data is determined based on the power grid conditions, including: determining a calculation object, and determining related objects based on the calculation object; wherein the calculation object and related objects include substations and transmission lines; determining a calculation boundary based on the calculation object and related objects; determining an operation mode and a maintenance mode, and determining the calculation mode based on the operation mode and the maintenance mode.

[0024] In practical applications, the system calculation boundary should at least include the upper-level substation and transmission line to the calculation object substation or transmission line, and the calculation boundary can also be expanded according to actual operation needs; the calculation method should at least include the normal mode before and after the calculation object substation or transmission line is put into operation, and the maintenance mode of any line or component within the aforementioned calculation range after commissioning. Of course, the calculation method can be simplified according to actual conditions, but it should be able to include the worst case. In special cases, the superimposed maintenance method of lines and components can also be considered.

[0025] The calculation boundary is the radiation range of the substation or transmission line, and the calculation method is the calculation method corresponding to the substation or transmission line within the radiation range.

[0026] For example, Figure 2 The above steps are specifically described by taking the newly built substation 10 connected to a regional power grid as an example. First, determine the calculation objects, which are the newly built substation 10, the double-circuit transmission line 1-10, and the double-circuit transmission line 9-10. The related objects are the upper-level substations and transmission lines associated with the calculation objects, namely substations 1, 3, 7, 8 and transmission lines 1-3, 8-9, 7-9. Determine the calculation boundary based on the aforementioned calculation objects and related objects, namely Figure 2 The inner part of the coil is shown.

[0027] Determine the calculation method, including the following: Commissioning method: Start substation 10 and transmission lines 1-10, 9-10 from the substation 1 side, or start substation 10 and transmission lines 1-10, 9-10 from the substation 9 side.

[0028] Maintenance mode: The maintenance mode of any line or component within the calculation boundary range, after considering the simplification of the calculation method, generally includes the following 16 maintenance modes. Specifically: maintenance of one circuit of transmission line 1-10; maintenance of one line of transmission line 9-10; maintenance of two lines of transmission line 9-10; maintenance of one line of transmission line 8-9; maintenance of two lines of transmission line 8-9; maintenance of one line of transmission line 7-9; maintenance of two lines of transmission line 7-9; maintenance of one line of transmission line 1-3; maintenance of one main transformer of substation 10; maintenance of one main transformer of substation 1; maintenance of one main transformer of substation 9; maintenance of busbar high-voltage reactor of substation 9; maintenance of one circuit of transmission line 1-10; maintenance of one line of transmission line 9-10; maintenance of two lines of transmission line 9-10.

[0029] In addition to the above-mentioned modes, it may also include a normal mode: a full wiring mode in which the substation 10 and the transmission lines 1-10, 9-10 are put into operation and operate normally.

[0030] Furthermore, simulation calculations are subsequently performed in simulation software based on the above-mentioned commissioning mode, normal mode and maintenance mode.

[0031] Step 102: Determine the system equivalent point based on the calculation method and the calculation boundary, and determine the equivalent calculation result.

[0032] In practical applications, the system equivalent points are determined according to the determined system calculation boundaries and calculation methods, and are generally substations, thermal power plants, and hydropower plant nodes. Figure 2 The system equivalent points shown are substations 1, 3, 7, 8, 9, and 10. The equivalent calculations of all the calculation methods are performed based on the determined system equivalent points based on the electromechanical transient simulation software, and the equivalent calculation results are equivalent voltage sources in the form of Thevenin, including voltage, phase angle, self-impedance, and mutual impedance between equivalent points. Figure 2 As shown, the equivalent calculation results in the normal mode are shown in Table 1. Table 1 is the equivalent calculation results of the system in the normal mode. Since the 220kV system has a ring network, there is mutual impedance between the equivalent points 8 and 9, 3 and 7. The equivalent calculation results of other modes are similar in form, and this specification embodiment will not be repeated. In different calculation modes, there may be an increase or decrease in mutual impedance due to the de-ringing of the 220kV power grid.

[0033] Table 1

[0034] Step 103: Determine the basic model of electromagnetic transient simulation based on the system equivalent points and calculation boundaries.

[0035] In a possible implementation, a basic model of electromagnetic transient simulation is determined based on system equivalent points and calculation boundaries, including: determining a voltage source model and an impedance model, and determining an equivalent power source model and a self-impedance and mutual impedance model based on the system equivalent points, the voltage source model and the impedance model; determining a Bergeron model based on the calculation boundary, and establishing a frequency phase domain model corresponding to the calculation object; determining the basic model of electromagnetic transient simulation based on the equivalent power source model, the self-impedance model, the mutual impedance model, the Bergeron model and the frequency phase domain model.

[0036] Among them, the electromagnetic transient simulation basic model is determined based on the calculation boundary and the system equivalent point, which can be carried out based on the electromagnetic transient simulation software. The voltage source model adopts the ideal voltage source model in the electromagnetic transient simulation software model library, and the impedance model adopts the three-wire mutual coupling line model in the model library.

[0037] Furthermore, the line model is determined, and all line models within the calculation boundary range adopt the Bergeron form model, among which the calculation object line also needs to establish a frequency phase domain form model; if there is a line high-voltage reactor or a bus high-voltage reactor, the high-voltage reactor model needs to be determined, and the inductance model in the model library is adopted; the basic model of electromagnetic transient simulation is determined based on the Bergeron model and frequency phase domain model of the calculation object line.

[0038] In practical applications, based on the determined calculation boundaries and the determined system equivalent points, a basic model for system electromagnetic transient simulation is established, which mainly includes system equivalent power sources, transmission lines, busbar high-voltage reactors, line high-voltage reactors, measurement elements, etc.

[0039] Specifically, the method for establishing the basic model of electromagnetic transient simulation is as follows: the first step is to use the ideal voltage source and impedance model in the electromagnetic transient simulation software library, and establish the corresponding system equivalent power supply model and the mutual impedance model between the equivalent points according to the determined system equivalent points and equivalent results; the second step is to establish the model of all lines within the calculation boundary, and the Bergeron model is used here; the third step is to establish the frequency phase domain model of the calculation object line, considering the main tower structure of the line, the height of the hanging line, the transposition situation, etc.; the fourth step is to establish the mutual impedance model between different equivalent nodes according to the equivalent calculation results, and the impedance model is used here to represent it; the fifth step is to use the inductance element to establish the corresponding model if there are line high reactance and bus high reactance, and the small reactance of the line high reactance also uses the inductance model; the sixth step is to add the bus voltage, phase angle, line flow measurement and oscilloscope elements on the basis of the above, according to the grid structure of the calculation boundary, to form two basic example models, and the calculation object line model uses the Bergeron model and the frequency phase domain model respectively, which are used for the subsequent simulation calculation of different internal overvoltage projects.

[0040] For example, follow the above steps to create Figure 2 The corresponding electromagnetic transient simulation basic model is shown in Figure 3 shown.

[0041] Step 104: Generate a system electromagnetic transient simulation model based on the electromagnetic transient simulation basic model and the equivalent calculation results.

[0042] In a possible implementation, a system electromagnetic transient simulation model is generated based on an electromagnetic transient simulation basic model and equivalent calculation results, including: determining a calculation example model based on the equivalent calculation results and the electromagnetic transient simulation basic model; determining simulation results of the calculation example model, and generating a system electromagnetic transient simulation model based on comparison of the simulation results and the power flow results.

[0043] In practical applications, based on the equivalent calculation result data of all calculation methods and the generated system electromagnetic transient simulation basic model, the system electromagnetic transient simulation models under all calculation methods are generated in batches, and compared with the power flow calculation results to verify the correctness of the model.

[0044] For details, see Figure 4 , a method for batch generating all calculation method example models based on equivalent calculation result data and electromagnetic transient simulation basic model, first obtain the total number N of all calculation methods to be generated; second, derive the model parameter table from the electromagnetic transient simulation basic model, including the equivalent voltage source parameter table and the impedance parameter table, as shown in Table 2 and Table 3, Table 2 is the electromagnetic transient model equivalent voltage source parameter table, Table 3 is the electromagnetic transient model impedance parameter table. In the equivalent voltage source parameter table in Table 2, the effective value Vm and phase angle Ph of the line voltage of each node need to be written, and the default values ​​of the other parameters can be used; in the impedance parameter table in Table 3, the positive sequence resistance Rp, positive sequence inductance Lp, zero sequence resistance Rz, and zero sequence inductance Lz need to be written, and the default values ​​of the other parameters can be used. The third step is to read the equivalent calculation result data of calculation method n. The specific result form is shown in Table 1. The voltage, phase angle, positive sequence resistance R1, positive sequence inductance L1, zero sequence resistance R0 and zero sequence inductance L0 are written into the equivalent voltage source parameter table shown in Table 2 and the impedance parameter table shown in Table 3 respectively; the fourth step is to import Table 2 and Table 3 after writing the equivalent result data into the electromagnetic transient simulation basic model to generate the calculation method n example model; the fifth step is to run the calculation method n example model, read the node voltage and phase angle, line flow, and compare them with the flow results before the equivalent value to determine whether they are consistent. If they are consistent, proceed to the next step, otherwise, return to the second step to check whether the result is wrong; the fifth step is to determine whether n=N is true? If true, end; otherwise, n=n+1, return to the second step, and generate the next calculation method example model.

[0045] Specifically, the method of importing equivalent result data into the basic calculation example model is as follows: taking the normal method as an example, the voltage and phase angle in the equivalent result data shown in Table 1 correspond to the effective value of the line voltage Vm and the phase angle Ph in Table 2, respectively, and the positive sequence resistance R1, positive sequence inductance L1, zero sequence resistance R0 and zero sequence inductance L0 correspond to the positive sequence resistance Rp, positive sequence inductance Lp, zero sequence resistance Rz and zero sequence inductance Lz in Table 3, respectively. Here, the mapping and automatic batch writing of the equivalent result data in Table 1 to the corresponding parameters in Table 2 and Table 3 are realized by matching the node names. Specifically, the equivalent point names in the equivalent result data in Table 1 are expressed in Chinese, while the node names in the electromagnetic transient simulation software are in English, as shown in Table 2 and Table 3. Therefore, it is first necessary to add a column of English node names in Table 1 that corresponds to the node names in Table 2 and Table 3 one by one, as shown in Table 4, the equivalent calculation results of the system under normal mode. In this way, the program searches for matching node names to realize the automatic batch writing of each parameter one by one.

[0046] Table 2

[0047] Table 3

[0048] Table 4

[0049] Step 105: Determine an internal overvoltage calculation item, and determine a project function module based on the internal overvoltage calculation item.

[0050] In practical applications, the internal overvoltage calculation project mainly refers to the power frequency overvoltage calculation and operation overvoltage calculation, the back-supply current and recovery voltage calculation, etc., but it is not limited to this. For each of the above-mentioned internal overvoltage calculation projects, a customized secondary development of related functional calculation modules is carried out based on the electromagnetic transient simulation software to form a general model library, which can be directly called in different projects. The general model library mainly includes the power frequency overvoltage calculation module, the operation overvoltage calculation module, the back-supply current and recovery voltage calculation module, etc. Each calculation module mainly includes circuit breakers at both ends of the line, lightning arresters, fault modules, measurement elements, output elements, data records, etc. Figure 5 The figure shows an example of a general calculation model library for internal overvoltage, which is applicable to lines with single-circuit installation and double-circuit installation on the same tower, and can also be expanded to lines with other wiring forms.

[0051] The specific implementation is explained by taking the power frequency overvoltage calculation module applicable to the single-circuit line as an example. Figure 6aAs shown, it includes the power frequency overvoltage calculation line model part, which is composed of circuit breakers at both ends of the line, line lightning arresters, fault modules, voltage measurement components, line high-voltage reactors, line high-voltage reactor disconnectors, high-voltage reactor neutral point small reactors, line models, etc. When using, just place the specific line model in the "Line Model" part. At the same time, see Figure 6b , load shedding controllers are set up, including load shedding for no fault on the left and right sides of the line and single-phase grounding fault load shedding controllers. There is no need to repeatedly modify the circuit breaker control logic module time, which has good convenience and high efficiency, and also avoids the errors that may be caused by frequent manual parameter modification. Figure 6b , a result display and recording module is set up, which can intuitively read the bus voltage nominal value and the line end voltage standard value as well as the phase voltage and line voltage waveforms. The waveforms are as follows Figure 6c As shown, the “Multiple Run Additional Recording” module is used to record the result data, which is used to automatically record the result data in subsequent batch simulation calculations, avoiding possible errors in manual data recording and ensuring the accuracy of the results.

[0052] Step 106: Determine a target electromagnetic transient simulation model based on the project functional module and the system electromagnetic transient simulation model.

[0053] Among them, the target electromagnetic transient simulation model is the electromagnetic transient model after adding the calculation project function module.

[0054] In a possible implementation, a target electromagnetic transient simulation model is determined based on a project function module and a system electromagnetic transient simulation model, including: adding the system electromagnetic transient simulation model based on the project function module, and setting the electrical node name of the project function module to the same node name as the calculation object to obtain the target electromagnetic transient simulation model.

[0055] Usually, the calculation project of overvoltage within the power frequency is based on the system electromagnetic transient basic model using the Bergeron form line model, and the calculation projects such as operating overvoltage, secondary supply current and recovery voltage, and outgoing line grounding switch verification are based on the system electromagnetic transient simulation model using the frequency phase domain form line model.

[0056] In practical applications, select the internal overvoltage calculation project to be performed, select the corresponding calculation project function module from the general model library, and add it to the generated system electromagnetic transient simulation model.

[0057] Specifically, the target electromagnetic transient simulation model can be obtained by adding the selected calculation project function module to the basic calculation example model and setting the module interface electrical node name to the same node name as the required calculation object line. In one calculation example, multiple calculation project function modules can be added for multiple calculation object lines.

[0058] Step 107: Determine a high-efficiency simulation calculation module based on the internal overvoltage calculation project, and perform simulation calculation based on the target electromagnetic transient simulation model and the high-efficiency simulation calculation module to determine a simulation result.

[0059] In a possible implementation, simulation calculations are performed based on a target electromagnetic transient simulation model and an efficient simulation calculation module to determine simulation results, including: determining action timing implementation based on the efficient simulation calculation module, and performing simulation calculations based on the action timing implementation and the target electromagnetic transient simulation model to determine simulation results.

[0060] Specifically, the efficient simulation calculation module of the internal overvoltage calculation project corresponds to the project function module described in step 105 according to the specific project, and the simulation calculation is mainly performed by Figure 6a The combined action of the circuit breaker elements and fault module elements on both sides of the line in the functional module of the project shown is realized. For the specific calculation content of the specific calculation project, its action timing is fixed and unchanged, and it is suitable for simulation calculations of different projects and different calculation examples. The action timing is different for different calculation contents of different calculation projects. Therefore, different efficient simulation calculation modules are developed for different calculation projects of internal overvoltage calculation. In each module, according to the specific calculation project and calculation content, the universal action timing of the circuit breaker and fault module elements is set to realize batch efficient simulation of the same calculation project under different calculation methods for one engineering calculation example, and also realize efficient simulation of the same calculation project under different calculation methods for different engineering calculation examples. Furthermore, batch efficient simulation of different calculation projects of one engineering calculation example can also be realized. Taking the power frequency internal overvoltage calculation project as an example, the calculation content includes the power frequency overvoltage calculation under four conditions: three-phase load shedding without fault at the head end of the line, load shedding with single-phase grounding fault at the head end of the line, load shedding without fault at the end of the line, and load shedding with single-phase grounding fault at the end of the line. The action timing of the circuit breaker and fault module components of the power frequency internal overvoltage calculation project is shown in Table 5. In the above four cases, the action timing of the circuit breaker and fault components on both sides of the line is different. Among them, Tb represents the circuit breaker action time, that is, the tripping load shedding time at the head end or end of the line, and its value must be less than the simulation time of the example; Tf represents the fault component action time, that is, the time when a single-phase grounding fault occurs at the head end or end of the line, and its value must be less than Tb; 888 is used here to indicate that the circuit breaker or fault component does not act, and any other value greater than the simulation time of the example can also be set.

[0061] For the 1 normal mode and 16 maintenance modes described in step 101, each calculation mode needs to perform a power frequency overvoltage calculation, and each power frequency overvoltage calculation needs to perform the calculations in the four cases shown in the table. In the power frequency overvoltage efficient calculation module, a set of action timings in the four cases shown in Table 5 is set, and for variables Tb and Tf, a set of general default parameters are set, and user input parameter selection is set at the same time. The set of action timing parameters is applicable to the power frequency overvoltage calculations of the aforementioned 17 calculation modes, based on which efficient batch simulation calculations can be achieved.

[0062] Table 5 Operation sequence of power frequency overvoltage calculation circuit breaker and fault module components

[0063] In practical applications, see Figure 7 , Figure 7 The figure shows the efficient simulation calculation process. The first step is to input relevant calculation information before calculation, which generally includes the name of the calculation object line, the name of the pre-calculation case, the number of lines M and the number of cases N; the second step is to obtain the component numbers of the internal circuit breaker components and fault module components of all calculation project function modules in the case, and then call the components and set component parameters through the component numbers. For the target electromagnetic transient model of a specified project, when performing overvoltage calculations in different modes, the numbers of the circuit breakers and fault module components in the calculation project function module are fixed, so they can be entered once for a specified project; the third step is to set the action sequence of the circuit breaker components and the fault module components. Here, the action sequence includes the action time and the number of actions. Generally, the default general parameters are set for fixed calculation projects, and they can also be modified according to actual conditions; the fourth step is to set the output file name of the calculation result data; the fifth step is to perform the simulation calculation of each calculation content under the selected project of the nth calculation example of the mth calculation object line one by one, where m=1,2,…,M, n=1,2,…,N; the sixth step is to determine whether the current simulation example of the mth calculation object line is n=N? Yes, go to the seventh step; No, m=m, n=n+1, return to the fifth step. The seventh step is to determine the number of current calculation object lines m=M? Yes, end; No, m=m+1, n=1, return to the fifth step.

[0064] In a possible implementation, the method further includes: analyzing and processing the simulation results to determine analysis results; and formatting the analysis results to determine an analysis report.

[0065] In practical applications, the batch analysis and processing method for the output calculation result files is as follows: first, batch convert the generated .out files into .excel files that can be edited and processed; second, analyze and process the data converted into Excel format according to different calculation projects, generate table data that meets the calculation report requirements, and merge them into an Excel file; finally, generate a word file according to the required format for the result data after analysis and processing.

[0066] The embodiment of this specification provides a method and device for simulating electromagnetic transient overvoltage in an AC power transmission and transformation system, including: determining calculation data based on power grid conditions; determining system equivalent points based on calculation boundaries and calculation methods, and determining equivalent calculation results; determining electromagnetic transient simulation basic models based on system equivalent points and calculation boundaries; generating system electromagnetic transient simulation models based on electromagnetic transient simulation basic models and equivalent calculation results; determining internal overvoltage calculation projects, and selecting project function modules based on internal overvoltage calculation projects; determining target electromagnetic transient simulation models based on project function modules and system electromagnetic transient simulation models; determining efficient simulation calculation modules based on internal overvoltage calculation projects, and performing simulation calculations based on target electromagnetic transient simulation models and efficient simulation calculation modules, and determining simulation results. The modularization, controllability and process-based nature of internal overvoltage calculations are achieved, which can improve calculation efficiency and accuracy, and save time and labor costs. In addition, the embodiment of this specification has good scalability and versatility, and can also be extended to efficient simulation calculations of internal overvoltage electromagnetic transients in new energy delivery systems, DC power transmission and transformation systems, etc.

[0067] Corresponding to the above method embodiment, this specification also provides an embodiment of an overvoltage electromagnetic transient simulation device in an AC power transmission and transformation system, Figure 8 FIG. 1 is a schematic diagram showing the structure of an overvoltage electromagnetic transient simulation device in an AC power transmission and transformation system provided by an embodiment of the present specification. Figure 8 As shown, the device comprises: The data determination module 801 is configured to determine the power grid conditions and determine the calculation data based on the power grid conditions; wherein the calculation data includes a calculation boundary and a calculation method; The equivalent point determination module 802 is configured to determine the equivalent point of the system based on the calculation boundary and the calculation method, and determine the equivalent calculation result; A basic model determination module 803 is configured to determine an electromagnetic transient simulation basic model based on system equivalent points and calculation boundaries; The transient model determination module 804 is configured to generate a system electromagnetic transient simulation model based on the electromagnetic transient simulation basic model and the equivalent calculation result; A calculation item determination module 805 is configured to determine an internal overvoltage calculation item and select an item function module based on the internal overvoltage calculation item; The target model determination module 806 is configured to determine an internal overvoltage calculation item and select an item function module based on the internal overvoltage calculation item; The simulation calculation module 807 is configured to determine a high-efficiency simulation calculation module based on the internal overvoltage calculation item, and perform simulation calculation based on the target electromagnetic transient simulation model and the high-efficiency simulation calculation module to determine a simulation result.

[0068] In a possible implementation, determining the calculation data based on the power grid situation includes: Determine a calculation object, and determine a related object based on the calculation object; wherein the calculation object and the related object include a substation and a transmission line; Determine a computation boundary based on the computation object and related objects; Determine the commissioning method and maintenance method, and determine the calculation method based on the commissioning method and maintenance method.

[0069] In a possible implementation, the basic model of electromagnetic transient simulation is determined based on the system equivalent points and the calculation boundary, including: Determine the voltage source model and the impedance model, and determine the equivalent power source model, the self-impedance model and the mutual impedance model based on the system equivalent point, the voltage source model and the impedance model; Determine the Bergeron model based on the calculation boundary and establish the frequency phase domain model corresponding to the calculation object; The basic model of electromagnetic transient simulation is determined based on the equivalent power supply model, self-impedance model, mutual impedance model, Bergeron model and frequency phase domain model.

[0070] In a possible implementation, a system electromagnetic transient simulation model is generated based on the electromagnetic transient simulation basic model and the equivalent calculation result, including: Determine the calculation model based on the equivalent calculation results and the basic model of electromagnetic transient simulation; Determine the simulation results of the case model, compare the simulation results with the power flow results, and generate a system electromagnetic transient simulation model.

[0071] In a possible implementation, determining a target electromagnetic transient simulation model based on a project functional module and a system electromagnetic transient simulation model includes: The system electromagnetic transient simulation model is added based on the project function module, and the electrical node name of the project function module is set to the same node name as the calculation object to obtain the target electromagnetic transient simulation model.

[0072] In a possible implementation, simulation calculation is performed based on a target electromagnetic transient simulation model and an efficient simulation calculation module to determine a simulation result, including: The action timing realization is determined based on the efficient simulation calculation module, and the simulation calculation is performed based on the action timing realization and the target electromagnetic transient simulation model to determine the simulation result.

[0073] In a possible implementation, the method further includes: Analyze and process the simulation results to determine the analysis results; The analysis results are formatted and the analysis report is determined.

[0074] The embodiments of this specification provide a method and device for simulating electromagnetic transient overvoltage in an AC power transmission and transformation system, including: determining calculation data based on power grid conditions; determining system equivalent points based on calculation boundaries and calculation methods, and determining equivalent calculation results; determining electromagnetic transient simulation basic models based on system equivalent points and calculation boundaries; generating system electromagnetic transient simulation models based on electromagnetic transient simulation basic models and equivalent calculation results; determining internal overvoltage calculation projects, and selecting project function modules based on internal overvoltage calculation projects; determining target electromagnetic transient simulation models based on project function modules and system electromagnetic transient simulation models; determining efficient simulation calculation modules based on internal overvoltage calculation projects, and performing simulation calculations based on target electromagnetic transient simulation models and efficient simulation calculation modules, and determining simulation results. The modularization, controllability and process-based nature of internal overvoltage calculations are achieved, which can improve calculation efficiency and accuracy, and save time and labor costs.

[0075] The above is a schematic scheme of an overvoltage electromagnetic transient simulation device in an AC power transmission and transformation system of this embodiment. It should be noted that the technical scheme of the overvoltage electromagnetic transient simulation device in the AC power transmission and transformation system and the technical scheme of the overvoltage electromagnetic transient simulation method in the AC power transmission and transformation system are of the same conception, and the details not described in detail in the technical scheme of the overvoltage electromagnetic transient simulation device in the AC power transmission and transformation system can be referred to the description of the technical scheme of the overvoltage electromagnetic transient simulation method in the AC power transmission and transformation system.

[0076] Fig. 9 The structure block diagram of a computing device 900 provided according to an embodiment of the present specification is shown. The components of the computing device 900 include but are not limited to a memory 910 and a processor 920. The processor 920 is connected to the memory 910 via a bus 930, and a database 950 is used to store data.

[0077] The computing device 900 also includes an access device 940 that enables the computing device 900 to communicate via one or more networks 960. Examples of these networks include a public switched telephone network (PSTN), a local area network (LAN), a wide area network (WAN), a personal area network (PAN), or a combination of communication networks such as the Internet. The access device 940 may include one or more of any type of network interface (e.g., a network interface card (NIC)) that is wired or wireless, such as an IEEE 802.11 wireless local area network (WLAN) wireless interface, a world-wide interoperability for microwave access (Wi-MAX) interface, an Ethernet interface, a universal serial bus (USB) interface, a cellular network interface, a Bluetooth interface, and a near field communication (NFC).

[0078] In one embodiment of the present specification, the above components of the computing device 900 and Fig. 9 Other components not shown in the figure may also be connected to each other, for example, via a bus. It should be understood that Fig. 9 The computing device structure block diagram shown is only for the purpose of illustration, and is not intended to limit the scope of this specification. Those skilled in the art can add or replace other components as needed.

[0079] The computing device 900 may be any type of stationary or mobile computing device, including a mobile computer or mobile computing device (e.g., a tablet computer, a personal digital assistant, a laptop computer, a notebook computer, a netbook, etc.), a mobile phone (e.g., a smart phone), a wearable computing device (e.g., a smart watch, smart glasses, etc.), or other types of mobile devices, or a stationary computing device such as a desktop computer or a personal computer (PC). The computing device 900 may also be a mobile or stationary server.

[0080] The processor 920 is used to execute the following computer executable instructions, which, when executed by the processor, implement the steps of the above-mentioned method for simulating overvoltage electromagnetic transients in an AC power transmission and transformation system. The above is a schematic scheme of a computing device of this embodiment. It should be noted that the technical scheme of the computing device and the technical scheme of the above-mentioned method for simulating overvoltage electromagnetic transients in an AC power transmission and transformation system belong to the same concept. The details of the technical scheme of the computing device that are not described in detail can be found in the description of the technical scheme of the above-mentioned method for simulating overvoltage electromagnetic transients in an AC power transmission and transformation system.

[0081] An embodiment of the present specification also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the above-mentioned method for simulating overvoltage electromagnetic transients in an AC power transmission and transformation system.

[0082] The above is a schematic scheme of a computer-readable storage medium of this embodiment. It should be noted that the technical scheme of the storage medium and the technical scheme of the overvoltage electromagnetic transient simulation method in the AC power transmission and transformation system mentioned above belong to the same concept, and the details not described in detail in the technical scheme of the storage medium can be referred to the description of the technical scheme of the overvoltage electromagnetic transient simulation method in the AC power transmission and transformation system mentioned above.

[0083] An embodiment of the present specification further provides a computer program, wherein when the computer program is executed in a computer, the computer is caused to execute the steps of the above-mentioned method for simulating overvoltage electromagnetic transients in an AC power transmission and transformation system.

[0084] The above is a schematic scheme of a computer program of this embodiment. It should be noted that the technical scheme of the computer program and the technical scheme of the overvoltage electromagnetic transient simulation method in the AC power transmission and transformation system are of the same concept, and the details not described in detail in the technical scheme of the computer program can be found in the description of the technical scheme of the overvoltage electromagnetic transient simulation method in the AC power transmission and transformation system.

[0085] The above is a description of a specific embodiment of the specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0086] The computer instructions include computer program codes, which may be in source code form, object code form, executable files or some intermediate forms, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable medium may be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0087] It should be noted that, for the above-mentioned method embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the embodiments of this specification are not limited by the order of the actions described, because according to the embodiments of this specification, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the embodiments of this specification.

[0088] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0089] The preferred embodiments of this specification disclosed above are only used to help explain this specification. The optional embodiments do not describe all the details in detail, nor do they limit the invention to only the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of the embodiments of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the embodiments of this specification, so that technicians in the relevant technical field can well understand and use this specification. This specification is only limited by the claims and their full scope and equivalents.

Claims

1. A method for simulating overvoltage electromagnetic transient in an AC power transmission and transformation system, characterized in that: include: Determine the power grid conditions, and determine calculation data based on the power grid conditions; wherein the calculation data includes a calculation boundary and a calculation method; Determine the system equivalent point based on the calculation boundary and calculation method, and determine the equivalent calculation result; Determine an electromagnetic transient simulation basic model based on the system equivalent points and the calculation boundary; Generate a system electromagnetic transient simulation model based on the electromagnetic transient simulation basic model and the equivalent calculation result; Determine an internal overvoltage calculation project, and select a project function module based on the internal overvoltage calculation project; Determining a target electromagnetic transient simulation model based on the project function module and the system electromagnetic transient simulation model; A high-efficiency simulation calculation module is determined based on the internal overvoltage calculation item, and simulation calculation is performed based on the target electromagnetic transient simulation model and the high-efficiency simulation calculation module to determine a simulation result.

2. The method according to claim 1, characterized in that The determining of calculation data based on the power grid condition comprises: Determine a calculation object, and determine a related object based on the calculation object; wherein the calculation object and the related object include a substation and a transmission line; determining a computation boundary based on the computation object and the related object; Determine a commissioning method and a maintenance method, and determine a calculation method based on the commissioning method and the maintenance method.

3. The method according to claim 1, characterized in that The determining of the electromagnetic transient simulation basic model based on the system equivalent point and the calculation boundary includes: Determine a voltage source model and an impedance model, and determine an equivalent power source model, a self-impedance model and a mutual impedance model based on the system equivalent point, the voltage source model and the impedance model; Determine a Bergeron model based on the calculation boundary, and establish a frequency phase domain model corresponding to the calculation object; An electromagnetic transient simulation basic model is determined based on the equivalent power source model, the self-impedance model, the mutual impedance model, the Bergeron model and the frequency phase domain model.

4. The method according to claim 1, characterized in that The generating of the system electromagnetic transient simulation model based on the electromagnetic transient simulation basic model and the equivalent calculation result comprises: Determine a calculation example model based on the equivalent calculation result and the electromagnetic transient simulation basic model; Determine the simulation result of the example model, compare the simulation result with the power flow result, and generate a system electromagnetic transient simulation model.

5. The method according to claim 1, characterized in that The determining of the target electromagnetic transient simulation model based on the project function module and the system electromagnetic transient simulation model includes: The system electromagnetic transient simulation model is added based on the project function module, and the electrical node name of the project function module is set to the same node name as the calculation object to obtain the target electromagnetic transient simulation model.

6. The method according to claim 1, characterized in that The performing simulation calculation based on the target electromagnetic transient simulation model and the efficient simulation calculation module to determine the simulation result includes: The action timing realization is determined based on the efficient simulation calculation module, and the simulation calculation is performed based on the action timing realization and the target electromagnetic transient simulation model to determine the simulation result.

7. The method according to claim 1, characterized in that Also includes: Analyzing and processing the simulation results to determine analysis results; Format processing is performed based on the analysis result to determine an analysis report.

8. An overvoltage electromagnetic transient simulation device in an AC power transmission and transformation system, characterized in that: include: A data determination module is configured to determine a power grid condition and determine calculation data based on the power grid condition; wherein the calculation data includes a calculation boundary and a calculation method; An equivalent point determination module is configured to determine the system equivalent point based on the calculation boundary and the calculation method, and determine the equivalent calculation result; A basic model determination module is configured to determine an electromagnetic transient simulation basic model based on the system equivalent points and the calculation boundary; A transient model determination module is configured to generate a system electromagnetic transient simulation model based on the electromagnetic transient simulation basic model and the equivalent calculation result; a calculation item determination module configured to determine an internal overvoltage calculation item and select an item function module based on the internal overvoltage calculation item; A target model determination module is configured to determine a target electromagnetic transient simulation model based on the project function module and the system electromagnetic transient simulation model; The simulation calculation module is configured to determine a high-efficiency simulation calculation module based on the internal overvoltage calculation item, and perform simulation calculation based on the target electromagnetic transient simulation model and the high-efficiency simulation calculation module to determine a simulation result.

9. A computing device, characterized in that include: Memory and processor; The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the overvoltage electromagnetic transient simulation method in the AC power transmission and transformation system described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the method for simulating overvoltage electromagnetic transients in an AC power transmission and transformation system as described in any one of claims 1 to 7.

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