Method and system for verifying accuracy of short-circuit current calculation method

Abstract

The invention discloses a method and system for verifying the accuracy of a short-circuit current calculation method, and the method comprises the steps: determining key elements of a power system, and building a short-circuit current calculation method accuracy evaluation model; based on the parameters of the key elements, generating a calculation example set of the short-circuit current, and determining constraint conditions of the key elements; based on a short-circuit current calculation method accuracy evaluation model, calculating a short-circuit current theoretical maximum value of each calculation example in a short-circuit current calculation example set; calculating a short-circuit current engineering calculation value of each calculation example adopting the short-circuit current engineering calculation method; obtaining a difference value between the theoretical maximum value of the short-circuit current of each example and the engineering calculation value of the short-circuit current; and when the difference value of each example meets a preset threshold value, the short-circuit current engineering calculation method is verified to be accurate. The technical scheme of the invention has universality for all short-circuit current calculation methods, and can also be used for comparing and analyzing the accuracy of different short-circuit current calculation methods.

Description

Technical Field

[0001] The present invention relates to the technical field of power system planning and operation, and more specifically, to a method and system for verifying the accuracy of a short-circuit current calculation method. Background Art

[0002] In the planning, design and operation control of power systems, short-circuit current calculations are required for the selection of system equipment capacity parameters and the arrangement of operation modes. The purpose of professional short-circuit current calculations in power systems is to calculate the maximum short-circuit current, that is, to obtain the maximum short-circuit current that the switchgear may experience during its entire life cycle. The results of short-circuit current calculations have a significant impact on the coordination of system safety and economy. If the calculated result is too large, it is necessary to select a larger capacity switchgear and increase investment; it may also cause the short-circuit level evaluation results of more sites to exceed the standard, and additional current limiting measures will be added. While increasing investment, the reliability of system operation may be reduced. If the calculated result is too small, although it will save a one-time equipment investment, the circuit breaker equipment may face insufficient interrupting capacity, affecting the safety of the equipment and system.

[0003] With the development of the power grid, the short-circuit current of the power grid is high and presents a global development trend. The short-circuit current of some power stations in the load center area and even some sending-end power grids is gradually approaching or exceeding the rated breaking capacity of the switch. This puts higher requirements on the accuracy of the short-circuit current calculation method. Due to historical reasons, different decision-making departments in the same region have long adopted different short-circuit current calculation methods, resulting in large differences in calculation results and making decisions difficult. At present, there are two basic calculation methods mainly used in engineering, namely the equivalent voltage source method based on the national standard for short-circuit current calculation and the calculation method of the internal potential E"=1 of the generator.

[0004] At present, except for the method of verifying the accuracy of the equivalent voltage source method proposed in GB / T 15544.2 Three-phase AC system short-circuit current calculation Part 2: Coefficients for application of short-circuit current calculation, there are no other methods for evaluating the accuracy of short-circuit current calculation methods.

[0005] Therefore, a technology is needed to verify the accuracy of the short-circuit current calculation method. Summary of the invention

[0006] The technical solution of the present invention provides a method and system for verifying the accuracy of a short-circuit current calculation method, so as to solve the problem of how to verify the readiness of the short-circuit current calculation method.

[0007] In order to solve the above problem, the present invention provides a method for verifying the accuracy of a short-circuit current calculation method, the method comprising:

[0008] Determine the key components of the power system and establish a short-circuit current calculation method accuracy evaluation model including the key components;

[0009] Based on the parameters of the key components, a set of calculation examples of short-circuit current is generated, and constraint conditions of the key components are determined;

[0010] Calculating the short-circuit current theoretical maximum value of each calculation example in the short-circuit current calculation example set based on the accuracy evaluation model of the short-circuit current calculation method;

[0011] Calculate the short-circuit current engineering calculation value of each calculation example using the short-circuit current engineering calculation method;

[0012] Obtain the difference between the theoretical maximum short-circuit current and the engineering calculated short-circuit current of each calculation example;

[0013] When the difference between the calculation examples meets the preset threshold, the short-circuit current engineering calculation method is verified to be accurate.

[0014] Preferably, the key elements include: a generator transformer group, a transmission line and a three-winding step-down transformer.

[0015] Preferably, in the accuracy evaluation model of the short-circuit current calculation method, the short-circuit point is set on the medium-voltage side of the three-winding step-down transformer, and the short-circuit current of the generator transformer group is calculated.

[0016] Preferably, the short-circuit current calculation method accuracy evaluation model is used to calculate the short-circuit current theoretical maximum value of each calculation example in the short-circuit current calculation example set, and the safe operation conditions of the power system are also met, including:

[0017] The generator output meets the generator power circle diagram; the transmission line voltage is within the allowable range; the adjustment range of the three-winding step-down transformer connector is considered to ensure that the machine-end voltage and high-voltage side voltage are within the preset reasonable operating range.

[0018] Preferably, the step of obtaining the difference between the theoretical maximum short-circuit current of each calculation example and the engineering calculated value of the short-circuit current includes:

[0019] The difference between the theoretical maximum short-circuit current and the engineering calculated short-circuit current of each case Δ S Expressed as a percentage:

[0020]

[0021] Among them, I' k ' e is the engineering calculation value of the short-circuit current of each case, I' k ' max is the theoretical maximum short-circuit current of each example.

[0022] Preferably, when the difference between the calculation examples meets a preset threshold, the short-circuit current engineering calculation method is verified to be accurate, including:

[0023] All differences in each case satisfy |Δ S |≤10%, and |Δ S |≤5% If the number of calculation examples exceeds 80% of the total number of calculation examples, the short-circuit current engineering calculation method is verified to be accurate.

[0024] Preferably, it also includes:

[0025] When there are multiple verified short-circuit current engineering calculation methods, the short-circuit current engineering calculation method verified to be accurate shall be retained;

[0026] Select |Δ in the retained short-circuit current engineering calculation method S | is less than the threshold, Δ S The deviation direction is positive or negative, Δ S The short-circuit current engineering calculation method with a median deviation less than the threshold is used as the recommended short-circuit current engineering calculation method.

[0027] According to another aspect of the present invention, the present invention provides a system for verifying the accuracy of a short-circuit current calculation method, the system comprising:

[0028] An initial unit, used to determine key elements of the power system and establish an accuracy evaluation model for a short-circuit current calculation method including the key elements;

[0029] A generating unit, configured to generate a set of calculation examples of short-circuit current based on the parameters of the key elements, and determine the constraint conditions of the key elements;

[0030] A theoretical calculation unit, configured to calculate the short-circuit current theoretical maximum value of each calculation example in the short-circuit current calculation example set based on the accuracy evaluation model of the short-circuit current calculation method;

[0031] An engineering calculation unit, used for calculating the short-circuit current engineering calculation value of each calculation example using the short-circuit current engineering calculation method;

[0032] A difference calculation unit, used to obtain the difference between the theoretical maximum value of the short-circuit current and the engineering calculated value of the short-circuit current of each calculation example;

[0033] The result unit is used to verify that the short-circuit current engineering calculation method is accurate when the difference between each calculation example meets a preset threshold.

[0034] Preferably, the key elements include: a generator transformer group, a transmission line and a three-winding step-down transformer.

[0035] Preferably, in the accuracy evaluation model of the short-circuit current calculation method, the short-circuit point is set on the medium-voltage side of the three-winding step-down transformer, and the short-circuit current of the generator transformer group is calculated.

[0036] Preferably, the theoretical calculation unit is used to calculate the theoretical maximum value of the short-circuit current of each calculation example in the short-circuit current calculation example set based on the accuracy evaluation model of the short-circuit current calculation method, and also includes satisfying the safe operation conditions of the power system, and is also used to:

[0037] The generator output meets the generator power circle diagram; the transmission line voltage is within the allowable range; the adjustment range of the three-winding step-down transformer connector is considered to ensure that the machine-end voltage and high-voltage side voltage are within the preset reasonable operating range.

[0038] Preferably, the difference calculation unit is used to obtain the difference between the theoretical maximum value of the short-circuit current and the engineering calculated value of the short-circuit current in each calculation example, and is also used to:

[0039] The difference between the theoretical maximum short-circuit current and the engineering calculated short-circuit current of each case Δ S Expressed as a percentage:

[0040]

[0041] Among them, I' k ' e is the engineering calculation value of the short-circuit current of each case, I' k ' max is the theoretical maximum short-circuit current of each example.

[0042] Preferably, the result unit is used to verify that the short-circuit current engineering calculation method is accurate when the difference between each calculation example meets a preset threshold value, and is also used to:

[0043] All differences in each case satisfy |Δ S |≤10%, and |Δ S |≤5% If the number of calculation examples exceeds 80% of the total number of calculation examples, the short-circuit current engineering calculation method is verified to be accurate.

[0044] Preferably, the result unit is further used for:

[0045] When there are multiple verified short-circuit current engineering calculation methods, the short-circuit current engineering calculation method verified to be accurate shall be retained;

[0046] Select |Δ in the retained short-circuit current engineering calculation method S | is less than the threshold, Δ S The deviation direction is positive or negative, Δ SThe short-circuit current engineering calculation method with a median deviation less than the threshold is used as the recommended short-circuit current engineering calculation method.

[0047] The technical solution of the present invention provides a method and system for verifying the accuracy of a short-circuit current calculation method, wherein the method includes: determining key components of the power system, establishing an accuracy evaluation model for a short-circuit current calculation method including the key components; generating a set of calculation examples of short-circuit current based on the parameters of the key components, and determining the constraints of the key components; calculating the theoretical maximum value of short-circuit current for each example in the short-circuit current calculation example set based on the accuracy evaluation model of the short-circuit current calculation method; calculating the engineering calculation value of short-circuit current for each example using the short-circuit current engineering calculation method; obtaining the difference between the theoretical maximum value of short-circuit current for each example and the engineering calculation value of short-circuit current; when the difference between each example meets a preset threshold, the short-circuit current engineering calculation method is verified to be accurate. The technical solution of the present invention proposes a method and system for evaluating the accuracy of a short-circuit current calculation method, which is not targeted at a specific short-circuit current calculation method, but has universal applicability to all short-circuit current calculation methods, and can also be used to compare and analyze the accuracy of different short-circuit current calculation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0049] Figure 1 A flow chart of a method for verifying the accuracy of a short-circuit current calculation method according to a preferred embodiment of the present invention;

[0050] Figure 2 A schematic diagram of an accuracy evaluation model for a short-circuit current calculation method according to a preferred embodiment of the present invention;

[0051] Figure 3 A power circle diagram of a generator according to a preferred embodiment of the present invention;

[0052] Figure 4 A flow chart of a method for evaluating the accuracy of a short-circuit current calculation method according to a preferred embodiment of the present invention; and

[0053] Figure 5 A system structure diagram for verifying the accuracy of a short-circuit current calculation method according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0054] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0055] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0056] Figure 1 The present invention is a flowchart of a method for verifying the accuracy of a short-circuit current calculation method according to a preferred embodiment of the present invention.

[0057] The verification method for the calculation accuracy of the equivalent voltage source adopted in GB / T 15544.2 is to establish examples for verification of several core coefficients of the equivalent voltage source method. It is not suitable for the evaluation of the calculation accuracy of other methods, nor can it be used as an evaluation method for comparing the calculation accuracy of different short-circuit current calculation methods.

[0058] The present invention proposes a method for evaluating the accuracy of a short-circuit current calculation method. The method is not targeted at a specific short-circuit current calculation method, but is universal to all short-circuit current calculation methods, and can also be used to compare and analyze the accuracy of different short-circuit current calculation methods.

[0059] The method for verifying the accuracy of the short-circuit current calculation method proposed in the present invention can be directly applied to the accuracy evaluation of the short-circuit current calculation method, which is conducive to the decision-making department to select a more accurate basic method for short-circuit current calculation, promote the unification of short-circuit current calculation methods, provide technical support and decision-making basis for the selection of electrical equipment capacity in power grid planning and design schemes, preliminary demonstration and scheme comparison of major engineering projects, scientifically carry out power grid planning and design and ensure safe operation, and promote the coordination of power grid safety and economy.

[0060] like Figure 1 As shown, the present invention provides a method for verifying the accuracy of a short-circuit current calculation method, the method comprising:

[0061] Step 101: determining key components of the power system and establishing a short-circuit current calculation method accuracy evaluation model including the key components;

[0062] Preferably, the key elements include: a generator transformer group, a transmission line and a three-winding step-down transformer.

[0063] Preferably, in the short-circuit current calculation method accuracy evaluation model, the short-circuit point is set on the medium-voltage side of the three-winding step-down transformer, and the short-circuit current of the generator transformer group is calculated.

[0064] The present invention investigates the main components and parameters of the power system, the main components including a generator transformer group, a transmission line, and a three-winding step-down transformer.

[0065] The present invention establishes a short-circuit current calculation method accuracy evaluation model including main components of an electric power system, wherein the model includes a generator transformer group, a transmission line, and a three-winding step-down transformer.

[0066] In the present invention, the survey parameters are the parameters adopted by the evaluation method proposed in the present invention, and the survey parameter tables for designing the generator transformer group, line, and three-winding step-down transformer are shown in Table 1, Table 2, and Table 3, respectively.

[0067] In the present invention, the accuracy evaluation model of the short-circuit current calculation method is as follows: Figure 2 The short-circuit point is set on the medium-voltage side of the three-winding step-down transformer, and the short-circuit current provided by the left generator transformer group is calculated.

[0068] Step 102: generating a short-circuit current calculation example set based on the parameters of the key components, and determining the constraint conditions of the key components;

[0069] The present invention forms a set of calculation examples and proposes the operating constraints of each component in the accuracy evaluation model of the short-circuit current calculation method.

[0070] In the present invention, in the process of forming the example set, the line length needs to be subdivided, such as considering 4 groups of line lengths of 25km, 50km, 100km, and 150km respectively. The number of examples depends on the survey results in the above steps. For example, if the generator transformer group is surveyed into group a, the line model group b, the line length group c, and the three-winding step-down transformer group d, the total number of examples is x, satisfying x = a*b*c*d.

[0071] Step 103: Calculate the short-circuit current theoretical maximum value of each calculation example in the short-circuit current calculation example set based on the short-circuit current calculation method accuracy evaluation model;

[0072] Preferably, based on the short-circuit current calculation method accuracy evaluation model, the short-circuit current theoretical maximum value of each calculation example in the short-circuit current calculation example set is calculated, and the safe operation conditions of the power system are also met, including:

[0073] The generator output meets the generator power circle diagram; the transmission line voltage is within the allowable range; the adjustment range of the three-winding step-down transformer connector is considered to ensure that the machine-end voltage and high-voltage side voltage are within the preset reasonable operating range.

[0074] Preferably, obtaining the difference between the theoretical maximum value of the short-circuit current and the engineering calculated value of the short-circuit current of each calculation example includes:

[0075] The difference between the theoretical maximum short-circuit current and the engineering calculated short-circuit current of each case Δ S Expressed as a percentage:

[0076]

[0077] Among them, I″ ke is the engineering calculation value of short-circuit current for each case, I″ kmax is the theoretical maximum short-circuit current of each example.

[0078] The present invention calculates the possible (theoretical) maximum value of the short-circuit current in each calculation example.

[0079] The present invention can adopt the power flow iteration method to obtain the possible theoretical maximum value I″ of each example in the example set. kmax The system needs to meet the safe operation conditions, mainly including: the generator output meets the generator power circle diagram, such as Figure 3 The black solid line range shown in the figure is within the allowable range; the line voltage is within the allowable range; the adjustable range of the transformer tap is considered to ensure that the machine-end voltage and the high-voltage side voltage are within the reasonable operating range.

[0080] Table 1 Generator transformer group parameter survey table

[0081]

[0082] Table 2 Line parameter survey table

[0083]

[0084] Table 3 Three-winding step-down transformer parameter survey table

[0085]

[0086] Step 104: Calculate the short-circuit current engineering calculation value of each calculation example using the short-circuit current engineering calculation method;

[0087] The present invention adopts the short-circuit current engineering calculation method to obtain the short-circuit current I' in the example set under the engineering algorithm k ' e .

[0088] Step 105: Obtain the difference between the theoretical maximum short-circuit current and the engineering calculated short-circuit current of each calculation example;

[0089] The present invention obtains the difference between the short-circuit current engineering algorithm and the theoretical maximum value in each calculation example. For the convenience of observation, the difference ΔS It can be expressed as a percentage, as shown in formula (1).

[0090]

[0091] Step 106: When the difference between the calculation examples meets the preset threshold, the short-circuit current engineering calculation method is verified to be accurate.

[0092] Preferably, when the difference between each calculation example meets a preset threshold, the short-circuit current engineering calculation method is verified to be accurate, including:

[0093] All differences in each case satisfy |Δ S |≤10%, and |Δ S |≤5% If the number of calculation examples exceeds 80% of the total number of calculation examples, the short-circuit current engineering calculation method is verified to be accurate.

[0094] The present invention statistically calculates the differences between different methods and the theoretical maximum value.

[0095] The principle of sufficient accuracy of the engineering calculation method proposed in the present invention is that all calculation results in the example set satisfy |Δ S |≤10%, and |Δ S |≤5% If more than 80% of the calculation examples are exceeded, the engineering calculation method is considered to have sufficient accuracy.

[0096] Preferably, it also includes:

[0097] When there are multiple verified short-circuit current engineering calculation methods, the short-circuit current engineering calculation method verified to be accurate shall be retained;

[0098] Select |Δ in the retained short-circuit current engineering calculation method S | is less than the threshold, Δ S The deviation direction is positive or negative, Δ S The short-circuit current engineering calculation method with a median deviation less than the threshold is used as the recommended short-circuit current engineering calculation method.

[0099] In the present invention, a method with high calculation accuracy is selected as the recommended calculation method.

[0100] In the present invention, when the number of short-circuit current calculation methods to be evaluated is n, the method with sufficient accuracy selected in the above steps is retained. S | has a smaller range, Δ S The deviation direction is positive or negative, Δ S The method with small median deviation is recommended as the short-circuit current engineering algorithm.

[0101] The present invention proposes a method for evaluating the accuracy of a short-circuit current calculation method. The model established by the method covers the evaluation models of the main components in the power system and has wide applicability. A data survey table is proposed, which is easy for users to execute. The method is not targeted at a specific short-circuit current calculation method, and can evaluate the accuracy of any short-circuit current calculation method. It is not targeted at a specific voltage level and has strong robustness.

[0102] The present invention can evaluate the calculation accuracy of any short-circuit current calculation method, which is beneficial to practical engineering applications.

[0103] The following is an example of the implementation of the present invention:

[0104] The present invention adopts 13 groups of 500kV generator transformer group parameters, 1 type of line, 1 three-winding transformer, and 3 line lengths of 50km, 100km, and 150km to form 39 groups of calculation examples. Among them, 150km is arranged with high-voltage reactor according to 80% of the line charging power. Considering the reactive compensation of the three-winding transformer with 30% inductive capacity and 30% capacitive capacity, the deviation of the calculation results of evaluation method 1 (national standard algorithm) and method 2 (E″=1 algorithm) from the theoretical maximum value calculated by superposition method is shown in Table 4.

[0105] Table 4 Deviation of calculation results for 500kV system three-winding transformer

[0106]

[0107]

[0108] As can be seen from Table 4, the calculation results of method 1 are stable. In the two reactive compensation arrangements, the deviation ranges of 39 groups of examples are -6.87% to 1.06% and -6.26% to 0.81%, respectively. The absolute value of the deviation is less than 10%, of which 35 groups have an absolute value of deviation less than 5%, accounting for 90%, more than 80%. Method 2 is limited by the reactive compensation arrangement. Under the two arrangements, the deviations of its calculation method are -13.54% to -8.03% and -20.54% to -15.29%, respectively.

[0109] Based on the proposed evaluation method, the present invention recommends method 1 as the short-circuit current engineering calculation method.

[0110] Figure 5 A system structure diagram for verifying the accuracy of a short-circuit current calculation method according to a preferred embodiment of the present invention.

[0111] like Figure 5 As shown, the present invention provides a system for verifying the accuracy of a short-circuit current calculation method, the system comprising:

[0112] An initial unit 501 is used to determine key components of the power system and establish an accuracy evaluation model of a short-circuit current calculation method including the key components;

[0113] Preferably, the key elements include: a generator transformer group, a transmission line and a three-winding step-down transformer.

[0114] Preferably, in the short-circuit current calculation method accuracy evaluation model, the short-circuit point is set on the medium-voltage side of the three-winding step-down transformer, and the short-circuit current of the generator transformer group is calculated.

[0115] A generating unit 502, for generating a calculation example set of short-circuit current based on the parameters of the key components, and determining the constraint conditions of the key components;

[0116] Theoretical calculation unit 503, used to calculate the short-circuit current theoretical maximum value of each calculation example in the short-circuit current calculation example set based on the short-circuit current calculation method accuracy evaluation model;

[0117] Preferably, the theoretical calculation unit 503 is used to calculate the theoretical maximum value of the short-circuit current of each calculation example in the short-circuit current calculation example set based on the accuracy evaluation model of the short-circuit current calculation method, and also includes satisfying the safe operation conditions of the power system, and is also used to:

[0118] The generator output meets the generator power circle diagram; the transmission line voltage is within the allowable range; the adjustment range of the three-winding step-down transformer connector is considered to ensure that the machine-end voltage and high-voltage side voltage are within the preset reasonable operating range.

[0119] An engineering calculation unit 504, used to calculate the short-circuit current engineering calculation value of each calculation example using the short-circuit current engineering calculation method;

[0120] A difference calculation unit 505 is used to obtain the difference between the theoretical maximum value of the short-circuit current and the engineering calculated value of the short-circuit current in each calculation example;

[0121] Preferably, the difference calculation unit 505 is used to obtain the difference between the theoretical maximum value of the short-circuit current and the engineering calculated value of the short-circuit current in each calculation example, and is also used to:

[0122] The difference between the theoretical maximum short-circuit current and the engineering calculated short-circuit current of each case Δ S Expressed as a percentage:

[0123]

[0124] Among them, I' k ' e is the engineering calculation value of the short-circuit current of each case, I' k ' max is the theoretical maximum short-circuit current of each example.

[0125] The result unit 506 is used to verify that the short-circuit current engineering calculation method is accurate when the difference between the calculation examples meets a preset threshold.

[0126] Preferably, the result unit 506 is used to verify that the short-circuit current engineering calculation method is accurate when the difference between each calculation example meets a preset threshold value, and is also used to:

[0127] All differences in each case satisfy |Δ S |≤10%, and |Δ S |≤5% If the number of calculation examples exceeds 80% of the total number of calculation examples, the short-circuit current engineering calculation method is verified to be accurate.

[0128] Preferably, the result unit 506 is further used for:

[0129] When there are multiple verified short-circuit current engineering calculation methods, the short-circuit current engineering calculation method verified to be accurate shall be retained;

[0130] Select |Δ in the retained short-circuit current engineering calculation method S | is less than the threshold, Δ S The deviation direction is positive or negative, Δ S The short-circuit current engineering calculation method with a median deviation less than the threshold is used as the recommended short-circuit current engineering calculation method.

[0131] A system for verifying the accuracy of a short-circuit current calculation method in a preferred embodiment of the present invention corresponds to a method for verifying the accuracy of a short-circuit current calculation method in another preferred embodiment of the present invention, and will not be described in detail herein.

[0132] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0133] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0134] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0135] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0136] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0137] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0138] The invention has been described above with reference to a few embodiments. However, it is readily apparent to a person skilled in the art that other embodiments than the ones disclosed above are equally within the scope of the invention, as defined by the appended patent claims.

[0139] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a / said / the [means, components, etc.]" are to be openly interpreted as at least one instance of the means, components, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not necessarily have to be performed in the exact order disclosed, unless explicitly stated otherwise.

Claims

1. A method for verifying the accuracy of a short-circuit current calculation method, the method comprising: Determine the key components of the power system and establish a short-circuit current calculation method accuracy evaluation model including the key components; Based on the parameters of the key components, a set of calculation examples of short-circuit current is generated, and constraint conditions of the key components are determined; Calculating the short-circuit current theoretical maximum value of each calculation example in the short-circuit current calculation example set based on the accuracy evaluation model of the short-circuit current calculation method; Calculate the short-circuit current engineering calculation value of each calculation example using the short-circuit current engineering calculation method; Obtain the difference between the theoretical maximum short-circuit current and the engineering calculated short-circuit current of each calculation example; When the difference between the calculation examples meets the preset threshold, the short-circuit current engineering calculation method is verified to be accurate.

2. The method according to claim 1, wherein the key elements include: Generator transformer banks, transmission lines and three-winding step-down transformers.

3. According to the method of claim 1, in the accuracy evaluation model of the short-circuit current calculation method, the short-circuit point is set on the medium voltage side of the three-winding step-down transformer, and the short-circuit current of the generator transformer group is calculated.

4. The method according to claim 1, wherein the short-circuit current calculation method accuracy evaluation model is used to calculate the short-circuit current theoretical maximum value of each calculation example in the short-circuit current calculation example set, and further comprises satisfying the safe operation conditions of the power system, including: The generator output meets the generator power circle diagram; the transmission line voltage is within the allowable range; the adjustment range of the three-winding step-down transformer connector is considered to ensure that the machine-end voltage and high-voltage side voltage are within the preset reasonable operating range.

5. According to the method of claim 1, the step of obtaining the difference between the theoretical maximum short-circuit current of each calculation example and the engineering calculated short-circuit current value comprises: The difference between the theoretical maximum short-circuit current and the engineering calculated short-circuit current of each case Δ S Expressed as a percentage: Among them, I' k ' e is the engineering calculation value of the short-circuit current of each case, I' k ' max is the theoretical maximum short-circuit current of each example.

6. The method according to claim 5, wherein when the difference between the calculation examples meets a preset threshold, the short-circuit current engineering calculation method is verified to be accurate, comprising: All differences in each case satisfy |Δ S |≤10%, and |Δ S |≤5% If the number of calculation examples exceeds 80% of the total number of calculation examples, the short-circuit current engineering calculation method is verified to be accurate.

7. The method according to claim 6, further comprising: When there are multiple verified short-circuit current engineering calculation methods, the short-circuit current engineering calculation method verified to be accurate shall be retained; Select |Δ in the retained short-circuit current engineering calculation method S | is less than the threshold, Δ S The deviation direction is positive or negative, Δ S The short-circuit current engineering calculation method with a median deviation less than the threshold is used as the recommended short-circuit current engineering calculation method.

8. A system for verifying the accuracy of a short-circuit current calculation method, the system comprising: An initial unit, used to determine key elements of the power system and establish an accuracy evaluation model of a short-circuit current calculation method including the key elements; A generating unit, configured to generate a set of calculation examples of short-circuit current based on the parameters of the key elements, and determine the constraint conditions of the key elements; A theoretical calculation unit, configured to calculate the short-circuit current theoretical maximum value of each calculation example in the short-circuit current calculation example set based on the accuracy evaluation model of the short-circuit current calculation method; An engineering calculation unit, used for calculating the short-circuit current engineering calculation value of each calculation example using the short-circuit current engineering calculation method; A difference calculation unit, used to obtain the difference between the theoretical maximum value of the short-circuit current and the engineering calculated value of the short-circuit current of each calculation example; The result unit is used to verify that the short-circuit current engineering calculation method is accurate when the difference between each calculation example meets a preset threshold.

9. The system according to claim 8, wherein the key elements include: Generator transformer banks, transmission lines and three-winding step-down transformers.

10. The system according to claim 8, wherein in the accuracy evaluation model of the short-circuit current calculation method, the short-circuit point is set on the medium voltage side of the three-winding step-down transformer to calculate the short-circuit current of the generator transformer group.

11. The system according to claim 8, wherein the theoretical calculation unit is used to calculate the theoretical maximum value of the short-circuit current of each calculation example in the short-circuit current calculation example set based on the accuracy evaluation model of the short-circuit current calculation method, and further includes satisfying the safe operation conditions of the power system, and is also used to: The generator output meets the generator power circle diagram; the transmission line voltage is within the allowable range; the adjustment range of the three-winding step-down transformer connector is considered to ensure that the machine-end voltage and high-voltage side voltage are within the preset reasonable operating range.

12. The system according to claim 8, wherein the difference calculation unit is used to obtain the difference between the theoretical maximum value of the short-circuit current and the engineering calculated value of the short-circuit current in each calculation example, and is also used to: The difference between the theoretical maximum short-circuit current and the engineering calculated short-circuit current of each case Δ S Expressed as a percentage: in, I” ke is the engineering calculated value of short-circuit current for each case, I” kmax is the theoretical maximum short-circuit current of each example.

13. The system according to claim 12, wherein the result unit is used to verify that the short-circuit current engineering calculation method is accurate when the difference between each calculation example meets a preset threshold, and is also used to: All differences in each case satisfy |Δ S |≤10%, and |Δ S |≤5% If the number of calculation examples exceeds 80% of the total number of calculation examples, the short-circuit current engineering calculation method is verified to be accurate.

14. The system according to claim 13, wherein the result unit is further configured to: When there are multiple verified short-circuit current engineering calculation methods, the short-circuit current engineering calculation method verified to be accurate shall be retained; Select |Δ in the retained short-circuit current engineering calculation method S | is less than the threshold, Δ S The deviation direction is positive or negative, Δ S The short-circuit current engineering calculation method with a median deviation less than the threshold is used as the recommended short-circuit current engineering calculation method.

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