Substation current transformer relative error checking method and device and electronic equipment

Abstract

The application discloses a substation current transformer relative error checking method and device and electronic equipment, belongs to the wide-area high-voltage electric energy metering device operation error monitoring technical field, on the basis of the transmission metering structure, a local module is additionally arranged at the port of the reference line current transformer, and a test resistance R x is connected to the secondary side of the current transformer. By acquiring the data observation value of the current transformer and learning the absolute error of the reference line current transformer, the relative value of the parameter of the current transformer is accurately calculated by using a comprehensive error diagnosis algorithm in combination with the data observation value and the absolute error of the current transformer, so that the ratio error and the angle error of the current transformer are obtained, the influence of the line impedance under the conditions of long distance and large range is not neglected, the reliability of the checking method is improved, the application range is expanded, and a foundation is laid for popularizing the technology in a large area.

Description

Technical Field

[0001] This invention belongs to the field of wide-area high-voltage power metering device operation error monitoring technology, specifically involving a method, device and electronic equipment for verifying the relative error of current transformers in substations. Background Technology

[0002] In recent years, the construction of smart grids has been progressing rapidly. As a fundamental functional module of smart grids, electricity metering devices play a crucial role. The secondary circuit of the metering current transformer is a key component of the electricity metering system, but for a long time, its abnormal state has not been accurately and timely monitored. This not only causes significant economic losses to power supply companies, increases power supply costs, and adds to the burden on other users, affecting fair and orderly electricity use, but may also lead to safety accidents.

[0003] A current transformer is essentially a special type of transformer that converts a large primary current into a small secondary current, thereby unifying and standardizing various instruments and protection devices. Currently, the main technical methods for monitoring current transformer errors include multi-feature fuzzy recognition, high-frequency signal amplitude method, heterogeneous frequency method, amplitude-frequency characteristic curve method, and impedance characteristic method. These methods suffer from numerous problems, such as poor technical reliability, susceptibility to false alarms and missed alarms, narrow field applicability, susceptibility to environmental temperature and distributed parameters, susceptibility to ferromagnetic materials and secondary current, and significant technical defects, hindering widespread adoption. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the present invention aims to provide a method, device and electronic equipment for verifying the relative error of current transformers in substations, so as to solve the problems of poor reliability, easy false alarm and missed alarm, narrow field applicability, susceptibility to the influence of ambient temperature and distributed parameters, susceptibility to the influence of ferromagnetic materials and secondary current, and obvious technical defects in the existing technology for monitoring the error of current transformers, which prevent the technology from being widely promoted.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A method for verifying the relative error of current transformers in a wide-area substation includes the following steps:

[0007] Obtain the secondary side data observations of the current transformer and the absolute error of the reference line current transformer;

[0008] The secondary side data observations of the current transformer and the absolute error of the reference line current transformer are input into the comprehensive error diagnosis model for calculation to obtain the relative values ​​of the current transformer parameters.

[0009] The ratio difference and angle difference of the current transformer are calculated based on the relative values ​​of the parameters of the current transformer.

[0010] Preferably, obtaining the absolute error of the reference line current transformer specifically includes the following steps:

[0011] A test resistor R is set on the secondary side of the reference line current transformer. x Connected in parallel with the switch;

[0012] A local module and test resistor R are added at the outlet of the current transformer. x Connect to the switch;

[0013] The local module passes the test resistor R. x The absolute error of the reference line current transformer is obtained by comparing the circuit information of the switch.

[0014] Preferably, the data observations of the current transformer are obtained through an analog signal merging module; and before the data observations of the current transformer and the absolute error of the reference line current transformer are input into the comprehensive error diagnosis model, preprocessing is required, specifically including the following steps:

[0015] The fundamental current phasor on the secondary side was calculated using discrete Fourier analysis.

[0016] The calculated secondary fundamental current phasor is normalized.

[0017] Preferably, the fundamental current phasor on the secondary side is calculated using discrete Fourier analysis, and the calculation formula is as follows:

[0018]

[0019] In the formula, w m For window function; i ′ n,a Here, N represents the processed value of phase n of line a; N is the number of samples; m is a positive number starting from 1; i n,a (m) represents the sampled value of phase n of line a.

[0020] Preferably, the comprehensive error diagnosis model is as follows:

[0021] I2A=K

[0022] in The input is an m×n secondary current data matrix. The parameter value to be determined is... For residuals;

[0023] And:

[0024]

[0025] Where, δ k,i Let δ be the ratio difference of the i-th mutual inductor. θ,i Let be the angle difference of the i-th mutual inductor.

[0026] Preferably, the calculation in the comprehensive error diagnosis model, when the circuit being calculated is unloaded, specifically includes the following steps:

[0027] S201: Input m×n secondary current data matrix I2 and iteration step size α;

[0028] S202: Initialize the regression parameter matrix with A0, where A0 is a complex matrix;

[0029] S203: Calculate the cost function J and the new regression parameter matrix A for each iteration. i Specifically:

[0030]

[0031] S204: Repeat S202 until |A i+1 -A i |<10 -6 If the iteration stops, then stop.

[0032] S205: Using the first value of matrix A For reference, calculate the relative values ​​of the other elements of matrix A, then:

[0033]

[0034] S206: By

[0035]

[0036] Calculate the ratio difference δ k,i and angle difference δ θ,i ;

[0037] S207: Output parameter matrix δ k and δ θ .

[0038] Preferably, the calculation in the comprehensive error diagnosis model, when the circuit being calculated is a load, specifically includes the following steps:

[0039] S201: Input m×n secondary current data matrix I2 and iteration step size α, where the relationship between secondary current and primary current is:

[0040] but

[0041] S202: Assign initial values ​​A0 to the regression parameter matrix. A0 should be a complex matrix.

[0042] S203: Calculate the cost function J and the new regression parameter matrix A for each iteration. i Specifically:

[0043]

[0044] S204: Repeat S202 until |A i+1 -A i |<10 -6 If the iteration stops, then stop.

[0045] S205: Using the first value of matrix A For reference, calculate the relative values ​​of the other elements of matrix A, then:

[0046]

[0047] S206: By

[0048]

[0049] Calculate parameter x a and x b ;

[0050] S207: Derived from parameter x a and x b Calculate the ratio difference δ k,i and angle difference δ θ,i ;

[0051] S208: Output parameter matrix δ k and δ θ ;

[0052] Where I1 is the primary current; I2 is the secondary current; R m X is the magnetizing resistor; m X1 is the magnetizing reactance; R2 is the resistance of the secondary winding; X2 is the leakage reactance of the secondary winding; Z is the secondary load impedance; x a and x b The parameters are set; Z′ and I′2 are the secondary impedance and current value after the secondary current is changed by the active method, respectively.

[0053] This invention also discloses a relative error verification model for current transformers in wide-area substations, comprising:

[0054] The acquisition unit is used to acquire the secondary side data observation values ​​of the current transformer and the absolute error of the reference line current transformer.

[0055] The calculation unit is used to input the observed data values ​​of the current transformer and the absolute error of the reference line current transformer into the comprehensive error diagnosis model for calculation, and to obtain the relative values ​​of the parameters of the current transformer.

[0056] The output unit is used to calculate the ratio difference and angle difference of the current transformer based on the relative values ​​of the parameters of the current transformer.

[0057] The present invention also discloses an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the wide-area substation current transformer relative error verification method described above.

[0058] The present invention also discloses a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the wide-area substation current transformer relative error verification method described above.

[0059] Compared with the prior art, the present invention has the following beneficial effects:

[0060] This invention discloses a method for verifying the relative error of current transformers in substations. Considering the non-negligible line impedance, it obtains the secondary side data observations of the current transformers to determine the absolute error of the reference line current transformers. Using a comprehensive error diagnosis algorithm, combining the current transformer data observations and the absolute error, it accurately calculates the relative values ​​of the current transformer parameters, thereby obtaining the transformer's ratio error and phase angle error. This method does not neglect applications in long-distance, large-scale situations, and the influence of line impedance, improving the reliability of the verification method, expanding its applicability, and laying the foundation for widespread technology adoption. Simultaneously, it provides a new method for monitoring the errors of all current transformers on the busbar of high-voltage substations, enabling long-term online monitoring and effectively avoiding losses caused by abnormal current transformer conditions.

[0061] Furthermore, a test resistor R is installed on the secondary side of the reference line current transformer. x This is used to briefly change the secondary current, thereby obtaining the absolute error of the reference line current transformer. The local module converts and transmits the digital information of the current transformer's secondary circuit, then connects to a switch and sends it via optical fiber to the centralized metering device. Direct monitoring through the secondary circuit of the current transformer offers high accuracy, good real-time performance, and stable and reliable technology, without affecting metering, and enables long-term online monitoring. Attached Figure Description

[0062] Figure 1 This is a flowchart of the method of the present invention;

[0063] Figure 2 A schematic diagram of the traditional architecture for metering and monitoring of busbars in high-voltage substations;

[0064] Figure 3 This is a schematic diagram of the improved architecture for metering and monitoring of high-voltage substation busbars according to the present invention;

[0065] Figure 4 This is a residual diagram of one embodiment of the present invention;

[0066] Figure 5 This is a schematic diagram of the calculation results according to an embodiment of the present invention;

[0067] Figure 6 This is a schematic diagram of the parameter model of the current transformer of the present invention;

[0068] Figure 7 This is a schematic diagram of the device of the present invention;

[0069] Figure 8 This is a schematic diagram of the acquisition unit of the present invention. Detailed Implementation

[0070] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0071] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0072] The present invention will now be described in further detail with reference to the accompanying drawings:

[0073] See Figure 1 This invention discloses a method for verifying the relative error of current transformers in a wide-area substation, comprising the following steps:

[0074] S1: Obtain the secondary side data observation values ​​of the current transformer and the absolute error of the reference line current transformer;

[0075] S2: The data observation values ​​of the current transformer and the absolute error of the reference line current transformer are input into the comprehensive error diagnosis model for calculation;

[0076] S3: Output the relative values ​​of the current transformer parameters to obtain the ratio difference and phase difference of the current transformer.

[0077] This invention, taking into account the non-negligible line impedance, obtains the absolute error of the reference line current transformer while acquiring the data observation values ​​of the current transformer. By using a comprehensive error diagnosis algorithm, combining the data observation values ​​and absolute error of the current transformer, the relative values ​​of the current transformer parameters are accurately calculated, thereby obtaining the ratio error and angle error of the transformer. It does not ignore the impact of line impedance in applications with long distances and large areas, improves the reliability of the verification method, expands the scope of application, and lays the foundation for the widespread promotion of the technology.

[0078] In some embodiments, obtaining the absolute error of the reference line current transformer specifically includes the following steps:

[0079] A test resistor R is set on the secondary side of the reference line current transformer. x Connected in parallel with the switch;

[0080] A local module and test resistor R are added at the outlet of the current transformer. x Connect to the switch;

[0081] The local module passes the test resistor R. x The absolute error of the reference line current transformer is obtained by comparing the circuit information of the switch.

[0082] Adding a local module at the current transformer's output has two advantages. First, it allows for the collection and synchronous processing of secondary circuit information at the current transformer's output when the current transformer is some distance from the substation and the line impedance is not negligible. This information is then transmitted to the switch via fiber optic cable, effectively eliminating the influence of line impedance. Second, it allows for the monitoring of the aforementioned test resistor R. x The secondary current and secondary voltage after being connected to the secondary side are collected and processed in real time, and then connected to the switch and transmitted to the centralized metering device via optical fiber.

[0083] In some embodiments, the data observations of the current transformer are obtained through an analog signal merging module; and before the data observations of the current transformer and the absolute error of the reference line current transformer are input into the comprehensive error diagnosis model, preprocessing is required, specifically including the following steps:

[0084] The fundamental current phasor on the secondary side was calculated using discrete Fourier analysis.

[0085] The calculated secondary fundamental current phasor is normalized.

[0086] In some embodiments, the fundamental current phasor on the secondary side is calculated using discrete Fourier analysis, and the calculation formula is as follows:

[0087]

[0088] In the formula, w m For window functions; Here, N represents the processed value of phase n of line a; N is the number of samples; m is a positive number starting from 1; i n,a (m) represents the sampled value of phase n of line a.

[0089] In some embodiments, the comprehensive error diagnosis model is specifically:

[0090] I2A=K

[0091] in The input is an m×n secondary current data matrix. The parameter value to be determined is... For residuals;

[0092] And:

[0093]

[0094] Where, δ k,i Let δ be the ratio difference of the i-th mutual inductor. θ,i Let be the angle difference of the i-th mutual inductor.

[0095] In some embodiments, the calculation in the comprehensive error diagnosis model, when the circuit being calculated is unloaded, specifically includes the following steps:

[0096] S201: Input m×n secondary current data matrix I2 and iteration step size α;

[0097] S202: Assign initial values ​​A0 to the regression parameter matrix. A0 should be a complex matrix.

[0098] S203: Calculate the cost function J and the new regression parameter matrix A for each iteration. i Specifically:

[0099]

[0100] S204: Repeat S202 until |A i+1 -A i |<10 -6If the iteration stops, then stop.

[0101] S205: Using the first value of matrix A For reference, calculate the relative values ​​of the other elements of matrix A, then:

[0102]

[0103] S206: By

[0104]

[0105] Calculate the ratio difference δ k,i and angle difference δ θ,i ;

[0106] S207: Output parameter matrix δ k and δ θ .

[0107] In some embodiments, see Figure 4 The calculation in the comprehensive error diagnosis model, when the circuit being calculated is a load, specifically includes the following steps:

[0108] S201: Input m×n secondary current data matrix I2 and iteration step size α, where the relationship between secondary current and primary current is:

[0109]

[0110] S202: Assign initial values ​​A0 to the regression parameter matrix. A0 should be a complex matrix.

[0111] S203: Calculate the cost function J and the new regression parameter matrix A for each iteration. i Specifically:

[0112]

[0113] S204: Repeat S202 until |A i+1 -A i |<10 -6 If the iteration stops, then stop.

[0114] S205: Using the first value of matrix A For reference, calculate the relative values ​​of the other elements of matrix A, then:

[0115]

[0116] S206: By

[0117]

[0118] Calculate the ratio difference δ k,i and angle difference δθ,i ;

[0119] S207: Output parameter matrix δ k and δ θ ;

[0120] Where I1 is the primary current; I2 is the secondary current; R m X is the magnetizing resistor; m R1 is the magnetizing reactance; R2 is the resistance of the secondary winding; X2 is the leakage reactance of the secondary winding; Z is the secondary load impedance.

[0121] In some embodiments, see Figure 3 This method provides an online verification method for the relative error of current transformers in a wide-area high-voltage substation. It is combined with voltage and current transformers, local modules, merging units, switches, and centralized metering devices in the wide-area substation to monitor the relative error of all current transformers on the busbar of the high-voltage substation. The centralized metering device is equipped with a comprehensive error diagnosis unit: (1) preprocessing SV message data; (2) establishing a current transformer error diagnosis model; (3) using the comprehensive error diagnosis algorithm to perform relative error diagnosis on the secondary current data collected by the current transformer under zero magnetic flux conditions.

[0122] In some embodiments, (1) the SV message data is preprocessed: high-frequency synchronous acquisition data is obtained by means of the merging unit in the metering topology of the high-voltage substation. The data is sampled and recorded. The fundamental current phasor of its secondary side is calculated by discrete Fourier analysis. The formula for calculating the fundamental current phasor of the nth transformer is as follows:

[0123]

[0124] In the formula, w m Use some form of window function (not limited to Hamming window or Blackman window, etc.). Then normalize the data.

[0125] (2) Establishing an error diagnosis model for current transformers: Current transformers in actual operation have two types of errors: ratio error and phase error. By collecting and calculating the fundamental phasor values ​​of the secondary side of n transformers, an n-dimensional overdetermined regression equation system is established, as follows:

[0126] I2A=K

[0127] in The input is an m×n secondary current data matrix. The parameter value to be determined is... This is the residual.

[0128] And:

[0129]

[0130] Where δ k,i Let δ be the ratio difference of the i-th mutual inductor. θ,i Let be the angle difference of the i-th mutual inductor.

[0131] (3) Comprehensive Error Diagnosis Algorithm: First, the secondary current data collected by the current transformer under zero magnetic flux condition is analyzed. Based on the least squares regression principle, an optimal set of transformer ratio error δ is selected. k,1 ~δ k,n and angle difference δ k,1 ~δ k,n This minimizes the variance of the residual modulus of the above regression equation. The specific algorithm steps are as follows:

[0132] ① Input the m×n secondary current data matrix I2 and the iteration step size α;

[0133] ②Assign initial values ​​A0 to the regression parameter matrix, where A0 should be a complex matrix;

[0134] ③ Calculate the cost function J and the new regression parameter matrix A for each iteration using the following formula. i (i is the iteration number)

[0135]

[0136] ④ Repeat step (2) until |A i+1 -A i |<10 -6 If the iteration stops, then stop.

[0137] ⑤ Using the first value of matrix A For reference, calculate the relative values ​​of the other elements of matrix A, then:

[0138]

[0139] ⑥ By

[0140]

[0141] Calculate the ratio difference δ k,i and angle difference δ θ,i .

[0142] ⑦ Output parameter matrix δ k and δ θ .

[0143] In some embodiments, see Figure 2 In the traditional power metering architecture of high-voltage substations, each voltage and current transformer in the line is equipped with an analog quantity merging module, see [link to relevant documentation]. Figure 3The current transformer of the reference circuit in this application is connected to a test resistor R on its secondary side. x This is used to briefly change the secondary current, thereby obtaining the absolute error of the current transformer in the reference line. The merging unit merges and synchronizes the electrical quantities transmitted from the transformer, integrates the data observations into message data according to the standard protocol, and sends it to the switch. The switch receives the message data from multiple merging units and sends it to the centralized metering device via optical fiber. When the current transformer is close to the substation and the line is short, the above traditional structure can effectively realize the metering and monitoring of the current transformer. However, when the current transformer is a certain distance from the substation, the line impedance cannot be ignored. Based on the traditional structure, this disclosure adds a local module at the port of the current transformer in the reference line and connects a test resistor R to the secondary side of the current transformer. x The local module performs digital conversion and transmission of the secondary circuit information of the current transformer, and then connects to the switch to send it to the centralized metering device via optical fiber.

[0144] Compared to other technical solutions, its advantage lies in direct monitoring through the secondary circuit of the current transformer, which features high accuracy, good real-time performance, and stable and reliable technology. It does not affect metering and can achieve long-term online monitoring.

[0145] Figure 2 This is a schematic diagram of the traditional architecture for metering and monitoring of high-voltage substation busbars according to the present invention. Figure 2 As shown, there is a physical connection between the substation busbar and the lines, so the instantaneous values ​​of the in-phase currents from line 1 to line n satisfy the Kirchhoff's Current Law (KCL). Each line is connected to a current transformer (CT) and a voltage transformer (PT), which are then connected to an analog input merging unit. The merging unit merges and synchronizes the electrical quantities transmitted from the transformers. Data observations are integrated into message data according to a standard protocol and sent to the exchange. The received information is amplified and regenerated in the exchange. The exchange receives message data from multiple merging units and sends it to the centralized metering device via optical fiber.

[0146] Figure 3 This is a schematic diagram of the improved architecture for metering and monitoring of the high-voltage substation busbar according to the present invention. When the current transformer is close to the substation and the line is short, Figure 1 The traditional structure shown can effectively achieve metering and monitoring of current transformers. However, when the current transformer is a certain distance from the substation, the line impedance cannot be ignored. This disclosure adds a local module at the port of the current transformer based on the traditional structure, and connects a test resistor R to the secondary side of the current transformer. x It is used to briefly change the secondary current. The local module converts and transmits the digital information of the secondary circuit of the current transformer, and then connects to the switch to send it to the centralized metering device via optical fiber.

[0147] Figure 4 This is a residual diagram according to an embodiment of the present invention. The relative values ​​of the ratio difference and angle difference are calculated iteratively using secondary current data collected under zero flux conditions from the current transformers. The value of n is set to 3, assuming three current transformers are connected to the busbar. The true values ​​of the ratio difference and angle difference are set, and secondary current data are generated accordingly. 40 dB Gaussian noise is added to this data, and iterative calculations are performed. As shown in the figure, the residual decreases continuously with the increase of the number of iterations, eventually approaching 0. The residual value after iteration is less than 1 × 10⁻⁶. -4 This proves that the computational model is relatively accurate.

[0148] Figure 5 This is a schematic diagram of the calculation results according to an embodiment of the present invention; the first row shows the set values ​​for the regression coefficient, ratio difference, and angle difference, respectively, and the second row shows the calculated values ​​for these three quantities. It can be seen that, even with 40 dB Gaussian noise, the calculation results are close to the set values, with an absolute error within 1%.

[0149] Figure 6 This is a parametric model of a current transformer according to an embodiment of the present invention. A current transformer is essentially a special type of transformer. The parametric model of the present invention uses the T-type equivalent circuit of a transformer as a reference. Since the primary side of the current transformer can be considered as a current source, its primary impedance can be ignored. Figure 5 R m and X m Let R1 be the excitation resistance and excitation reactance, R2 be the secondary winding resistance and leakage reactance, and Z be the secondary load impedance. Then the relationship between the secondary current and the primary current is:

[0150]

[0151] By reconstructing the KCL equation using the above formula and performing least squares iteration, the coefficients before I2 can be obtained. The coefficients can be used to determine which current transformer is responsible for the error offset.

[0152] Using the active method, an active load is briefly connected to the secondary side of the current transformer with error deviation. With the primary current unchanged, the secondary current is changed to obtain a new equation:

[0153]

[0154] Z ′ and I2 ′ Let:

[0155] x a =R² + X² + R m +X m

[0156] x b =R m +X m

[0157] but:

[0158]

[0159] Based on the above formula, the x value of the error offset transformer can be calculated. a and x b Then, the load value is calculated from the measured secondary voltage and secondary current data, and the ratio difference and angle difference values ​​can be calculated.

[0160] See Figure 7 The present invention also discloses a relative error verification model for current transformers in wide-area substations, comprising:

[0161] The acquisition unit is used to acquire the data observation values ​​of the current transformer and the absolute error of the reference line current transformer.

[0162] The calculation unit is used to input the data observation values ​​of the current transformer and the absolute error of the reference line current transformer into the comprehensive error diagnosis model for calculation.

[0163] The output unit is used to output the relative values ​​of the parameters of the current transformer, thereby obtaining the ratio difference and phase difference of the current transformer.

[0164] In some embodiments, see Figure 8 The acquisition unit includes an analog quantity merging module and a local module;

[0165] The local module is used to obtain the absolute error of the reference line current transformer;

[0166] The analog quantity merging module is used to acquire the secondary side data observation values ​​of the current transformer.

[0167] The present invention also discloses an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the wide-area substation current transformer relative error verification method described above.

[0168] The present invention also discloses a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the wide-area substation current transformer relative error verification method described above.

[0169] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, apparatus, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0170] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0171] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0172] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0173] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for verifying the relative error of current transformers in a wide-area substation, characterized in that, Includes the following steps: Obtain the secondary side data observations of the current transformer and the absolute error of the reference line current transformer; obtaining the absolute error of the reference line current transformer specifically includes the following steps: A test resistor is installed on the secondary side of the reference line current transformer. Connected in parallel with the switch; Add a local module and test resistor at the outlet of the current transformer. Connect to the switch; Local module passes resistance test The absolute error of the reference line current transformer is obtained by comparing the circuit information of the switch. The observed secondary side data of the current transformer and the absolute error of the reference line current transformer are input into the comprehensive error diagnosis model for calculation to obtain the relative values ​​of the current transformer parameters. The comprehensive error diagnosis model establishes an n-dimensional overdetermined regression equation system by collecting and calculating the fundamental phasor values ​​of the secondary side of n current transformers. Specifically: in For input Secondary current data matrix The parameter value to be determined is... For residuals; And: in, Let the ratio difference of the i-th mutual inductor be . The angle difference of the i-th mutual inductor The ratio difference and angle difference of the current transformer are calculated based on the relative values ​​of the parameters.

2. The method for verifying the relative error of current transformers in a wide-area substation according to claim 1, characterized in that, The secondary side data observations of the current transformer are obtained through the analog signal merging module; and before the secondary side data observations of the current transformer and the absolute error of the reference line current transformer are input into the comprehensive error diagnosis model, preprocessing is required, specifically including the following steps: The fundamental current phasor on the secondary side was calculated using discrete Fourier analysis. The calculated secondary fundamental current phasor is normalized.

3. The method for verifying the relative error of current transformers in a wide-area substation according to claim 1, characterized in that, The calculation in the comprehensive error diagnosis model, when the circuit being calculated is unloaded, specifically includes the following steps: S201: Input Secondary current data matrix and iteration step size ; S202: Initialize the regression parameter matrix , It is a complex matrix; S203: Calculate the cost function J and the new regression parameter matrix for each iteration. Specifically: ； S204: Repeat S202 until... Then stop iterating; S205: Using the first value of matrix A For reference, calculate the relative values ​​of the other elements of matrix A, then: S206: By Calculate the ratio difference Sum of angle difference ; S207: Output parameter matrix and .

4. The method for verifying the relative error of current transformers in a wide-area substation according to claim 1, characterized in that, The calculation in the comprehensive error diagnosis model, when the circuit being calculated is a load, specifically includes the following steps: S201: Input Secondary current data matrix and iteration step size The relationship between the secondary current and the primary current is as follows: ,but ; S202: Initialize the regression parameter matrix , It should be a complex matrix; S203: Calculate the cost function J and the new regression parameter matrix for each iteration. Specifically: ； S204: Repeat S202 until... If the iteration stops, then stop. S205: Using the first value of matrix A For reference, calculate the relative values ​​of the other elements of matrix A, then: S206: By Calculation parameters and ; S207: By parameter and Calculate the ratio difference Sum of angle difference ; S208: Output parameter matrix and ; in, Primary current; It is a secondary current; For excitation resistor; For excitation reactance; The resistance of the secondary winding; Z is the leakage reactance of the secondary winding; Z is the secondary load impedance; and To set parameters; and These represent the secondary impedance and current value after the secondary current is changed using the active method.

5. A relative error verification device for current transformers in a wide-area substation, characterized in that, The method for verifying the relative error of current transformers in a wide-area substation as described in any one of claims 1 to 4 includes: The acquisition unit is used to acquire the data observation values ​​of the current transformer and the absolute error of the reference line current transformer. The calculation unit is used to input the data observation values ​​of the current transformer and the absolute error of the reference line current transformer into the comprehensive error diagnosis model for calculation, and obtain the relative values ​​of the parameters of the current transformer. The output unit is used to calculate the ratio difference and angle difference of the current transformer based on the relative values ​​of the parameters of the current transformer.

6. The relative error verification device for current transformers in a wide-area substation according to claim 5, characterized in that, The acquisition unit includes an analog quantity merging module and a local module; The local module is used to obtain the absolute error of the reference line current transformer; The analog quantity merging module is used to acquire the secondary side data observation values ​​of the current transformer.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the wide-area substation current transformer relative error verification method according to any one of claims 1-4.

8. A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the wide-area substation current transformer relative error verification method according to any one of claims 1-4.

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