Transformer adaptive closing method, device, equipment and storage medium

Abstract

The application discloses a transformer adaptive closing method and device, equipment and storage medium, and relates to the technical field of transformer control. The method comprises the following steps: obtaining a winding transient voltage signal in a tripping process of a target transformer, performing numerical integration on the winding transient voltage signal, and obtaining an initial residual magnetism value of the target transformer; obtaining a core leakage flux signal of the target transformer, performing complementary calibration on the initial residual magnetism value based on the core leakage flux signal, and obtaining a dynamic residual magnetism value of the target transformer; determining a target closing time based on the dynamic residual magnetism value of the target transformer, the type of the target transformer and the type of a circuit breaker corresponding to the target transformer; and controlling the circuit breaker to close the target transformer at the target closing time. Through the above method, accurate dynamic measurement of residual magnetism is realized, the ideal closing time with the minimum core residual magnetism and post-closing magnetic flux deviation is adaptively determined according to different transformer types and circuit breaker characteristics, and the magnetic field current surge is effectively inhibited.

Description

Technical Field

[0001] This application relates to the field of transformer control technology, and in particular to transformer inrush current suppression and adaptive closing methods, devices, equipment and storage media. Background Technology

[0002] The inrush current generated when a transformer is closed under no-load conditions can easily lead to relay protection malfunctions, increased winding mechanical stress, and degraded power quality, seriously affecting the safe and stable operation of the power system. Among existing suppression methods, phase-selective closing technology has been widely studied due to its significant effectiveness, but it still has the following shortcomings: the traditional voltage integration method is easily affected by line capacitance and the dispersion of circuit breaker operation; measurement methods based on inrush current or leakage flux have limited adaptability, making it difficult to accurately capture dynamically changing residual magnetism, resulting in insufficient accuracy in residual magnetism measurement; existing closing strategies have poor adaptability, limited applicable scenarios, and lack adaptive adjustment capabilities. Summary of the Invention

[0003] The main purpose of this application is to provide a transformer adaptive closing method, device, equipment and storage medium, which aims to solve the technical problems of insufficient residual magnetism measurement accuracy and poor adaptability of closing strategy in the prior art.

[0004] To achieve the above objectives, this application provides a transformer adaptive closing method, the method comprising: The transient voltage signal of the winding during the opening process of the target transformer is acquired, and the initial residual magnetism value of the target transformer is obtained by numerical integration of the transient voltage signal of the winding. The core leakage flux signal of the target transformer is obtained, and the initial residual magnetism value is calibrated based on the core leakage flux signal to obtain the dynamic residual magnetism value of the target transformer. The target closing time is determined based on the dynamic residual magnetism value of the target transformer, the type of the target transformer, and the type of the circuit breaker corresponding to the target transformer. At the target closing time, the circuit breaker is controlled to close the target transformer.

[0005] In one embodiment, the step of acquiring the winding transient voltage signal during the opening process of the target transformer and numerically integrating the winding transient voltage signal to obtain the initial residual magnetism value of the target transformer includes: Acquire the transient voltage signal of the winding during the tripping process of the target transformer, determine the peak voltage time based on the transient voltage signal, and use the peak voltage time as the lower limit of integration; The target fitting model is obtained by fitting the transient voltage signal of the winding based on a preset attenuation model. Based on the target fitting model, the moment when the transient voltage reaches the steady-state zero value is taken as the upper limit of integration; Based on the upper and lower limits of integration, the transient voltage signal of the winding is numerically integrated to obtain the initial residual magnetism of the target transformer.

[0006] In one embodiment, the step of determining the target closing time based on the dynamic residual magnetism value of the target transformer, the type of the target transformer, and the type of the circuit breaker corresponding to the target transformer includes: Based on the type of the target transformer, determine the pre-induced magnetic flux of the target transformer; The initial closing time is determined based on the dynamic residual magnetism of the target transformer, the pre-induced magnetic flux of the target transformer, and the type of the circuit breaker corresponding to the target transformer. The operating time deviation of the circuit breaker corresponding to the target transformer is determined, and the initial closing time is compensated based on the operating time deviation to obtain the target closing time.

[0007] In one embodiment, the step of determining the initial closing time based on the dynamic residual magnetism of the target transformer, the pre-induced magnetic flux of the target transformer, and the type of the circuit breaker corresponding to the target transformer includes: When the type of circuit breaker corresponding to the target transformer is a phase-operated circuit breaker, the steady-state flux amplitude is determined based on the pre-induced flux of the target transformer. Obtain the correspondence between dynamic residual magnetism, steady-state magnetic flux amplitude, grid frequency and initial closing time, and obtain the grid frequency; The initial closing time is determined based on the dynamic residual magnetism of the target transformer, the steady-state magnetic flux amplitude, the power grid frequency, and the corresponding relationship.

[0008] In one embodiment, the step of determining the initial closing time based on the dynamic residual magnetism of the target transformer, the pre-induced magnetic flux of the target transformer, and the type of the circuit breaker corresponding to the target transformer includes: When the type of circuit breaker corresponding to the target transformer is a three-phase linkage circuit breaker, the time when the total deviation is minimized is determined based on the pre-induced magnetic flux and dynamic residual magnetism of each phase of the target transformer. Based on the dynamic residual magnetism values ​​of each phase of the target transformer, the phase with the minimum residual magnetism is determined; At the moment when the total deviation is at its minimum, the flux matching moment corresponding to the phase with the minimum residual magnetism is determined, and the flux matching moment is taken as the initial closing moment.

[0009] In one embodiment, the step of determining the operating time deviation of the circuit breaker corresponding to the target transformer includes: When the target transformer is closed for the first time, the operating time deviation of the circuit breaker corresponding to the target transformer is determined based on the type of the target transformer and the dynamic residual magnetism value of the target transformer. When the target transformer is not closed for the first time, the stored historical action time deviation is obtained and used as the action time deviation of the circuit breaker corresponding to the target transformer.

[0010] In one embodiment, after the step of controlling the circuit breaker to close the target transformer at the target closing time, the method further includes: Collect the excitation current signal after the circuit breaker is closed; When the peak inrush current corresponding to the excitation current signal is greater than a preset current threshold, the target closing time is optimized.

[0011] Furthermore, to achieve the above objectives, this application also proposes a transformer adaptive closing device, which includes: The residual magnetism measurement module is used to acquire the transient voltage signal of the winding during the opening process of the target transformer, and to perform numerical integration on the transient voltage signal of the winding to obtain the initial residual magnetism value of the target transformer. The residual magnetism measurement module is also used to acquire the core leakage magnetic field signal of the target transformer, and perform complementary calibration on the initial residual magnetism value based on the core leakage magnetic field signal to obtain the dynamic residual magnetism value of the target transformer. The closing control module is used to determine the target closing time based on the dynamic residual magnetism value of the target transformer, the type of the target transformer, and the type of the circuit breaker corresponding to the target transformer; The closing execution module is used to control the circuit breaker to close the target transformer at the target closing time.

[0012] In addition, to achieve the above objectives, this application also proposes a transformer adaptive closing device, which includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the transformer adaptive closing method as described above.

[0013] In addition, to achieve the above objectives, the present invention also proposes a storage medium, which is a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the steps of the transformer adaptive closing method described above.

[0014] In addition, to achieve the above objectives, this application also provides a computer program product, which includes a computer program that, when executed by a processor, implements the steps of the transformer adaptive closing method described above.

[0015] This application provides an adaptive closing method for transformers. It acquires the transient voltage signal of the winding during the opening process of the target transformer, performs numerical integration on the transient voltage signal to obtain the initial residual magnetism value of the target transformer, acquires the core leakage flux signal of the target transformer, and performs complementary calibration on the initial residual magnetism value based on the core leakage flux signal to obtain the dynamic residual magnetism value of the target transformer. Based on the dynamic residual magnetism value of the target transformer, the type of the target transformer, and the type of circuit breaker corresponding to the target transformer, the target closing time is determined. At the target closing time, the circuit breaker is controlled to close the target transformer. This application combines voltage integration with leakage flux sensing complementary calibration to achieve accurate dynamic measurement of residual magnetism. It can adaptively determine the ideal closing time with the smallest deviation between the core residual magnetism and the magnetic flux after closing, suitable for different transformer types and circuit breaker characteristics. It is applicable to different scenarios, and the peak value of the inrush current after closing can be controlled within a certain range, effectively suppressing the inrush current. This solves the technical problems of insufficient residual magnetism measurement accuracy and poor adaptability of closing strategies in traditional solutions. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating an embodiment of the transformer adaptive closing method of this application; Figure 2 This is a flowchart illustrating Embodiment 2 of the transformer adaptive closing method of this application; Figure 3 This is a schematic diagram of the module structure of the transformer adaptive closing device according to an embodiment of this application; Figure 4 This is a schematic diagram of the equipment structure of the hardware operating environment involved in the transformer adaptive closing method in the embodiments of this application.

[0019] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0021] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0022] The main solution of this application embodiment is as follows: acquire the winding transient voltage signal during the opening process of the target transformer, perform numerical integration on the winding transient voltage signal to obtain the initial residual magnetism value of the target transformer; acquire the core leakage flux signal of the target transformer, perform complementary calibration on the initial residual magnetism value based on the core leakage flux signal to obtain the dynamic residual magnetism value of the target transformer; determine the target closing time based on the dynamic residual magnetism value of the target transformer, the type of the target transformer, and the type of circuit breaker corresponding to the target transformer; and control the circuit breaker to close the target transformer at the target closing time.

[0023] Currently, among existing suppression methods, phase-selective closing technology has been widely studied due to its significant effect, but it still has the following shortcomings: the traditional voltage integration method is easily affected by line capacitance and the dispersion of circuit breaker operation; the measurement methods based on inrush current or leakage flux have limited adaptability and are difficult to accurately capture dynamically changing residual magnetism, resulting in insufficient residual magnetism measurement accuracy; existing closing strategies have poor adaptability, limited applicable scenarios, and lack adaptive adjustment capabilities.

[0024] This application provides a solution that combines voltage integration method with leakage flux sensing complementary calibration to achieve accurate dynamic measurement of residual magnetism. It can also adaptively determine the ideal closing time with the smallest deviation between the residual magnetism of the iron core and the magnetic flux after closing for different transformer types and circuit breaker characteristics. It is applicable to different scenarios, and the peak value of the excitation inrush current after closing can be controlled within 35% of the rated current, which significantly suppresses the excitation inrush current. It solves the technical problems of insufficient residual magnetism measurement accuracy and poor adaptability of closing strategy in traditional solutions.

[0025] It should be noted that the executing entity in this embodiment can be a computing service device with data processing, network communication, and program execution functions, such as a tablet computer, personal computer, or mobile phone, or an electronic device or transformer adaptive closing device capable of the above functions. This embodiment does not specifically limit the scope of the embodiment. The following uses a transformer adaptive closing device as an example to describe this embodiment and the following embodiments.

[0026] This application provides a transformer adaptive closing method, referring to... Figure 1 , Figure 1 This is a flowchart illustrating the first embodiment of the transformer adaptive closing method of this application.

[0027] In this embodiment, the transformer adaptive closing method includes steps S10~S40: Step S10: Obtain the transient voltage signal of the winding during the opening process of the target transformer, and perform numerical integration on the transient voltage signal of the winding to obtain the initial residual magnetism value of the target transformer.

[0028] The target transformer is the transformer that needs to be closed. A voltage acquisition unit (such as a high-precision voltage transformer) can be used to acquire the transient winding voltage signal during the target transformer's opening process, denoted as... , , Sampling time, for The corresponding voltage value is collected over a time range from "start of the tripping action" to "voltage tending to a steady-state zero value". The sampling frequency must meet the requirements for capturing the transient voltage signal of the winding. For example, the sampling frequency is set to 200Hz, which can be flexibly adjusted according to the transformer voltage level. There is no specific limitation on this.

[0029] After the circuit breaker is tripped, residual magnetic flux, or residual magnetism, will remain in the core of the target transformer. The initial residual magnetism value is the residual magnetism obtained through preliminary calculation. Further complementary calibration is needed to accurately capture the dynamically changing residual magnetism, i.e., the dynamic residual magnetism value. Based on the dynamic residual magnetism value, this embodiment calculates the optimal closing time for different transformer types and different circuit breaker types to effectively suppress inrush current after closing.

[0030] It is understandable that a transformer typically contains three phases: A, B, and C. Therefore, in practical implementation, the initial residual magnetism values ​​corresponding to phases A, B, and C are calculated separately.

[0031] In one feasible implementation, step S10 may include steps S101 to S104: Step S101: Obtain the transient voltage signal of the winding during the opening process of the target transformer; determine the peak voltage time based on the transient voltage signal of the winding; and use the peak voltage time as the lower limit of integration. It should be noted that by iterating through the transient voltage signals of the winding, the point with the largest voltage amplitude is found, and the corresponding time is recorded. That is, the peak voltage moment, which serves as the lower limit of integration.

[0032] It is understandable that, in order to avoid interference causing fitting deviation, the transient voltage signal of the winding can be preprocessed before determining the voltage peak time, such as filtering and noise reduction, signal alignment. This embodiment does not make specific limitations on this.

[0033] Step S102: Fit the transient voltage signal of the winding based on the preset attenuation model to obtain the target fitting model; It should be noted that after the circuit breaker is tripped, the transient voltage exhibits an exponential decay trend due to the coupling effect of winding inductance and line capacitance (it does not suddenly return to zero). The voltage acquisition unit typically starts acquiring data from the moment the circuit breaker is tripped and stops acquiring data when the signal amplitude remains below a certain rough threshold for an extended period. This method delineates the approximate range of the winding transient voltage signal, but it cannot precisely determine the zero point. Therefore, directly determining the moment when the transient voltage reaches its steady-state zero value based on the acquired winding transient voltage signal is inaccurate. It is necessary to determine the true moment when the transient voltage reaches its steady-state zero value based on the decay law of the transient voltage.

[0034] Understandably, the preset attenuation model is a mathematical model that conforms to the transient voltage attenuation law. The transient voltage signal of the winding is fitted according to the preset attenuation model to determine the target fitting parameters. Based on the target fitting parameters and the preset attenuation model, a target fitting model is constructed. The least squares method can be used for fitting; no specific limitations are imposed.

[0035] For example, assume the preset decay model is an exponential decay model, i.e. ,in, For time variables, , , For fitting parameters, It can be the initial amplitude of the voltage signal. It can be a steady-state offset. It can be the decay time constant, and the target fitting parameters obtained by fitting are: , , Thus, the target fitting model can be obtained, i.e. .

[0036] Step S103: Based on the target fitting model, the moment when the transient voltage reaches the steady-state zero value is taken as the upper limit of integration; Understandably, after the fitting is completed, the moment when the transient voltage reaches its steady-state zero value is determined based on the target fitting model. This is used as the upper limit of the integration. In the specific implementation, corresponding judgment conditions can be set to determine it. For example, if The corresponding time is ,in, The threshold value is set.

[0037] Step S104: Based on the upper and lower limits of integration, the transient voltage signal of the winding is numerically integrated to obtain the initial residual magnetism of the target transformer.

[0038] Understandably, the initial remanence value can be solved by numerical integration, as shown in the integral formula below:

[0039] In the formula, This is the initial remanence value. This is the transient voltage signal of the winding. This is the maximum number of points. This is the lower limit of integration. This represents the number of turns in the winding.

[0040] It should be understood that the upper limit of integration is determined by fitting an exponentially decaying curve. This improves the accuracy of initial remanence calculation.

[0041] In addition, the Jiles-Athon model or the Preisach model can also be used for remanence calculation, and this embodiment does not specifically limit this.

[0042] Step S20: Obtain the core leakage flux signal of the target transformer, and perform complementary calibration on the initial residual magnetism value based on the core leakage flux signal to obtain the dynamic residual magnetism value of the target transformer.

[0043] It should be noted that the leakage magnetic field signal, i.e., the core leakage magnetic field signal, can be captured by a leakage magnetic field sensing unit (sensor) deployed on the outside of the transformer tank. The initial residual magnetism value is then calibrated using the core leakage magnetic field signal to obtain the dynamic residual magnetism value.

[0044] In one feasible implementation, step S20 may include: acquiring the core leakage flux signal of the target transformer; converting the core leakage flux signal into the corresponding leakage flux equivalent flux based on a preset mapping relationship; and weighting and fusing the leakage flux equivalent flux with the initial residual magnetism value based on dynamic weights to obtain the dynamic residual magnetism value of the target transformer.

[0045] It should be noted that the preset mapping relationship, i.e., the mapping relationship between the core leakage flux signal and the equivalent magnetic flux leakage flux, is determined according to the actual situation, for example: , These are the mapping coefficients.

[0046] Understandably, the leakage flux equivalent flux is calculated based on a preset mapping relationship, and a dynamic weighted fusion method is used to combine the initial remanent magnetization value. Equivalent magnetic flux to leakage flux Combine and correct errors. Specifically, set dynamic weights. Calculate the dynamic remanence value ,Right now Furthermore, the weights can be automatically fine-tuned based on actual conditions. This ensures a smooth fusion result.

[0047] It should be understood that, in practice, the dynamic remanent magnetization values ​​of phases A, B, and C need to be calculated based on the initial remanent magnetization values ​​of phases A, B, and C, respectively. The dynamic remanent magnetization values ​​of the three phases are often inconsistent.

[0048] It is understandable that this embodiment combines voltage integration method with leakage flux sensing complementary calibration to achieve accurate dynamic measurement of residual magnetism and effectively reduce the measurement error of dynamic residual magnetism.

[0049] In addition, in specific implementations, the dynamic remanence value can also be compensated based on temperature, but this embodiment does not impose specific limitations on this.

[0050] Step S30: Determine the target closing time based on the dynamic residual magnetism value of the target transformer, the type of the target transformer, and the type of the circuit breaker corresponding to the target transformer.

[0051] It should be noted that the target closing time is the optimal closing time. In this embodiment, a circuit breaker is used to realize the closing operation of the target transformer. The target transformer usually refers to an AC transformer, which can be of different types, such as: ordinary transformer, converter transformer, three-phase transformer, autotransformer, etc. The types of circuit breakers include at least phase-operated circuit breakers and three-phase interlocking circuit breakers.

[0052] It is understandable that, for different transformer types and different circuit breaker types, corresponding closing strategies (strategies for calculating the optimal closing time) are adaptively generated, thereby enabling the adaptive calculation of the optimal closing time.

[0053] Step S40: At the target closing time, control the circuit breaker to close the target transformer.

[0054] Understandably, the circuit breaker is controlled to complete the phase-by-phase closing operation or the three-phase linkage closing operation of the target transformer according to the optimal closing time.

[0055] Furthermore, in one feasible implementation, step S40 may include: acquiring the excitation current signal after closing; and optimizing the target closing time when the peak inrush current corresponding to the excitation current signal is greater than a preset current threshold.

[0056] It should be noted that the preset current threshold can be set to 35% of the rated current, but this embodiment does not impose a specific limitation on it.

[0057] Understandably, if the peak inrush current exceeds 35% of the rated current after the excitation current is collected after closing, the parameters involved in the complementary calibration process and the parameters involved in calculating the target closing time are adjusted for iterative optimization.

[0058] It should be understood that if the preset current threshold is set to 35% of the rated current, the peak value of the inrush current after closing can be controlled within 35% of the rated current. Compared with the random closing inrush current, the reduction in this embodiment is greater than or equal to 60%. Furthermore, this embodiment can continuously optimize parameters through feedback closed loop to improve the stability of long-term operation.

[0059] This embodiment provides an adaptive closing method for transformers. It acquires the transient voltage signal of the winding during the opening process of the target transformer, performs numerical integration on the transient voltage signal to obtain the initial residual magnetism value of the target transformer, acquires the core leakage flux signal of the target transformer, and performs complementary calibration on the initial residual magnetism value based on the core leakage flux signal to obtain the dynamic residual magnetism value of the target transformer. Based on the dynamic residual magnetism value of the target transformer, the type of the target transformer, and the type of circuit breaker corresponding to the target transformer, the target closing time is determined. At the target closing time, the circuit breaker is controlled to close the target transformer. This embodiment combines voltage integration and leakage flux sensing complementary calibration to achieve accurate dynamic measurement of residual magnetism. It can adaptively determine the ideal closing time with the smallest deviation between the core residual magnetism and the magnetic flux after closing, suitable for different transformer types and circuit breaker characteristics. It is applicable to different scenarios, and the peak value of the inrush current after closing can be controlled within a certain range, effectively suppressing the inrush current.

[0060] Based on the first embodiment of this application, in the second embodiment of this application, the content that is the same as or similar to that in Embodiment 1 above can be referred to the above description, and will not be repeated hereafter. Based on this, please refer to... Figure 2 Step S30 may include steps S301 to S303: Step S301: Determine the pre-induced magnetic flux of the target transformer based on the type of the target transformer.

[0061] It should be noted that the pre-induced magnetic flux is the ideal steady-state magnetic flux naturally generated in the transformer core by the grid voltage after the switch is closed. That is, the magnetic flux state that the core should reach after the switch is closed, which can be calculated accurately.

[0062] It is understandable that the calculation method for pre-induced magnetic flux differs depending on the type of transformer. The pre-induced magnetic flux for different types of target transformers can be determined based on practical experience.

[0063] Step S302: Determine the initial closing time based on the dynamic residual magnetism of the target transformer, the pre-induced magnetic flux of the target transformer, and the type of the circuit breaker corresponding to the target transformer.

[0064] It should be noted that the initial closing time is the closing time calculated in advance.

[0065] In one feasible implementation, step S302 may include steps A11 to A13: Step A11: When the type of circuit breaker corresponding to the target transformer is a phase-operated circuit breaker, determine the steady-state flux amplitude based on the pre-induced flux of the target transformer. It should be noted that the steady-state magnetic flux amplitude is the peak value of the pre-induced magnetic flux.

[0066] Step A12: Obtain the correspondence between dynamic residual magnetism, steady-state magnetic flux amplitude, grid frequency and initial closing time, and obtain the grid frequency; It should be noted that the correspondence between dynamic residual magnetism, steady-state magnetic flux amplitude, grid frequency, and initial closing time, i.e., the calculation formula for the initial closing time of the phase-operated circuit breaker, is as follows:

[0067] In the formula, This is the initial closing time. The steady-state magnetic flux amplitude, This is the dynamic remanence value. This refers to the power grid frequency.

[0068] Step A13: Determine the initial closing time based on the target transformer's dynamic residual magnetism, steady-state magnetic flux amplitude, grid frequency, and their corresponding relationships.

[0069] Understandably, by substituting the target transformer's dynamic residual magnetism, steady-state magnetic flux amplitude, and grid frequency into the above correspondence, the initial closing time can be calculated.

[0070] It should be understood that, in practical implementation, each phase of the target transformer has a corresponding pre-induced magnetic flux. If it is a phase-operated circuit breaker, the pre-induced magnetic flux of each phase is calculated, the corresponding steady-state magnetic flux amplitude is determined, and the initial closing time of each phase is calculated based on the correspondence between the dynamic residual magnetism, steady-state magnetic flux amplitude, grid frequency and initial closing time.

[0071] In another feasible implementation, step S302 may include steps B11-B13: Step B11: When the type of circuit breaker corresponding to the target transformer is a three-phase linkage circuit breaker, determine the time when the total deviation is minimized based on the pre-induced magnetic flux and dynamic residual magnetism of each phase of the target transformer. It should be noted that the moment of minimum total deviation is the moment when the sum of the deviations of the pre-induced magnetic flux and the dynamic residual magnetism of the three phases reaches its minimum.

[0072] Step B12: Determine the phase with the minimum residual magnetism based on the dynamic residual magnetism values ​​of each phase of the target transformer; It should be noted that the phase with the minimum remanence is the phase whose value is closest to 0 among the three phases of dynamic remanence.

[0073] It is understandable that a three-phase circuit breaker can only be closed simultaneously with all three phases, and it is impossible to match the optimal time for each phase individually. Therefore, this embodiment uses the time with the smallest total deviation to ensure that the overall inrush current is minimized after closing.

[0074] Step B13: At the moment of minimum total deviation, determine the flux matching moment corresponding to the phase of minimum residual magnetism, and use the flux matching moment as the initial closing moment.

[0075] Understandably, the moment with the minimum total deviation is selected as the candidate moment. The moment when the dynamic residual magnetism value corresponding to the phase with the minimum residual magnetism is closest to the pre-induced magnetic flux is found, which is the magnetic flux matching moment. This magnetic flux matching moment is used as the unique initial closing moment, thereby ensuring that no phase has an inrush current exceeding the limit on the basis of minimizing the total deviation.

[0076] It should be understood that, for a three-phase interlocking circuit breaker, the moment when the sum of the deviations between the three-phase residual magnetism and the pre-induced magnetic flux is minimized is determined, and then the moment when the magnetic flux matching of the phase with the minimum residual magnetism is selected as the initial closing moment is chosen.

[0077] Step S303: Determine the operating time deviation of the circuit breaker corresponding to the target transformer. Based on the operating time deviation, compensate for the initial closing time to obtain the target closing time.

[0078] Understandably, the operating time deviation, i.e. the circuit breaker's delay time, needs to be compensated for by adjusting the initial closing time to obtain the target closing time. For example, assuming the operating time deviation is 0.3ms and the initial closing time is 1.2ms, the target closing time is 0.9ms. The closing is controlled according to 0.9ms to ensure that the actual closing time of the circuit breaker falls exactly on the previously calculated target closing time.

[0079] It should be understood that, for a phase-by-phase circuit breaker, the target closing time is calculated for each phase based on its corresponding initial closing time, and each phase is closed according to its target closing time. For a three-phase interlocking circuit breaker, a unique target closing time is determined based on the finally determined unique initial closing time, and the three phases are closed according to the unique target closing time.

[0080] In one feasible implementation, the step of determining the operating time deviation of the circuit breaker corresponding to the target transformer may include: when the target transformer is closed for the first time, determining the operating time deviation of the circuit breaker corresponding to the target transformer based on the type of the target transformer and the dynamic residual magnetism value of the target transformer; when the target transformer is not closed for the first time, acquiring the stored historical operating time deviation and using the historical operating time deviation as the operating time deviation of the circuit breaker corresponding to the target transformer.

[0081] It should be noted that different closing scenarios use different action time deviations. Closing scenarios typically include two types: first-time closing and non-first-time closing. The historical action time deviation is the action time deviation used in the previous closing operation.

[0082] Understandably, if the target transformer is not being closed for the first time, the operating time deviation used in the previous closing operation will be used as the current operating time deviation. If the target transformer is being closed for the first time, the corresponding operating time deviation can be calculated based on the type of the target transformer, its dynamic residual magnetism, and practical experience.

[0083] For example, regarding the phase-selective closing of a conventional transformer, assuming the transformer parameters are: rated voltage 10 / 0.4kV, connection group Dyn11, rated capacity 30kVA, sampling frequency of 200Hz during opening, recording transient voltage signals, and determining the upper limit of integration through exponential decay fitting (… After calibration using leakage flux signals, the residual magnetism of phase A is output as -0.35 pu. Based on the phase-separated operation characteristics, the ideal closing time is calculated. The circuit breaker closed at the preset time, with a peak excitation current of 7.5A, accounting for 17.4% of the rated current. It was confirmed that no parameter adjustment was required.

[0084] For example, regarding the initial closing of a converter transformer, assuming the transformer parameters are: rated capacity 250MVA, rated voltage 500 / 220kV, considering the residual magnetism after testing, voltage integration combined with leakage flux calibration, the output three-phase residual magnetism is 0.2pu, -0.15pu, and 0.08pu, respectively. Considering the circuit breaker's static closed-loop operating time (64ms), and compensating for the operating deviation ±0.3ms, the closing time of phase A is determined to be 3ms after the voltage peak, with phases B and C closing delayed by 120°. The peak inrush current of the initial closing is ≤1A (per unit value 0.001), meeting the engineering requirements.

[0085] This embodiment provides a transformer adaptive closing method. Based on the type of the target transformer, the pre-induced magnetic flux of the target transformer is determined. Based on the dynamic residual magnetism of the target transformer, the pre-induced magnetic flux, and the type of the corresponding circuit breaker, the initial closing time is determined. The operating time deviation of the corresponding circuit breaker is determined, and the initial closing time is compensated to obtain the target closing time. This embodiment combines voltage integration and leakage flux sensing complementary calibration to achieve accurate dynamic measurement of residual magnetism. It can adaptively determine the ideal closing time with the smallest deviation between the core residual magnetism and the magnetic flux after closing, suitable for different transformer types and circuit breaker characteristics. It is applicable to various scenarios, and the peak value of the inrush current after closing can be controlled within a certain range, effectively suppressing the inrush current.

[0086] It should be noted that the above examples are only for understanding this application and do not constitute a limitation on the transformer adaptive closing method of this application. Any simple modifications based on this technical concept are within the protection scope of this application.

[0087] This application also provides a transformer adaptive closing device; please refer to [reference needed]. Figure 3 The transformer adaptive closing device includes: The residual magnetism measurement module 10 is used to acquire the winding transient voltage signal during the opening process of the target transformer, and to perform numerical integration on the winding transient voltage signal to obtain the initial residual magnetism value of the target transformer. The residual magnetism measurement module 10 is also used to acquire the core leakage magnetic signal of the target transformer, and perform complementary calibration on the initial residual magnetism value based on the core leakage magnetic signal to obtain the dynamic residual magnetism value of the target transformer. The closing control module 20 is used to determine the target closing time based on the dynamic residual magnetism value of the target transformer, the type of the target transformer, and the type of the circuit breaker corresponding to the target transformer. The closing execution module 30 is used to control the circuit breaker to close the target transformer at the target closing time.

[0088] In one feasible implementation, the residual magnetism measurement module 10 is also used to acquire the winding transient voltage signal during the opening process of the target transformer, determine the voltage peak time based on the winding transient voltage signal, and use the voltage peak time as the integration lower limit. The target fitting model is obtained by fitting the transient voltage signal of the winding based on the preset attenuation model; Based on the target fitting model, the moment when the transient voltage reaches the steady-state zero value is taken as the upper limit of integration; Based on the upper and lower limits of integration, the transient voltage signal of the winding is numerically integrated to obtain the initial residual magnetism of the target transformer.

[0089] In one feasible implementation, the closing control module 20 is also used to determine the pre-induced magnetic flux of the target transformer based on the type of the target transformer; The initial closing time is determined based on the dynamic residual magnetism of the target transformer, the pre-induced magnetic flux of the target transformer, and the type of the circuit breaker corresponding to the target transformer. Determine the operating time deviation of the circuit breaker corresponding to the target transformer, and compensate for the initial closing time based on the operating time deviation to obtain the target closing time.

[0090] In one feasible implementation, the closing control module 20 is also used to determine the steady-state flux amplitude based on the pre-induced flux of the target transformer when the type of the circuit breaker corresponding to the target transformer is a phase-operated circuit breaker. Obtain the correspondence between dynamic residual magnetism, steady-state magnetic flux amplitude, grid frequency and initial closing time, and obtain the grid frequency; The initial closing time is determined based on the target transformer's dynamic residual magnetism, steady-state magnetic flux amplitude, grid frequency, and their corresponding relationships.

[0091] In one feasible implementation, the closing control module 20 is also used to determine the time of minimum total deviation based on the pre-induced magnetic flux and dynamic residual magnetism of each phase of the target transformer when the type of the circuit breaker corresponding to the target transformer is a three-phase linkage circuit breaker. Based on the dynamic residual magnetism values ​​of each phase of the target transformer, the phase with the minimum residual magnetism is determined; At the moment of minimum total deviation, determine the flux matching moment corresponding to the phase of minimum residual magnetism, and use the flux matching moment as the initial closing moment.

[0092] In one feasible implementation, the closing control module 20 is also used to determine the operating time deviation of the circuit breaker corresponding to the target transformer based on the type of the target transformer and the dynamic residual magnetism value of the target transformer when the target transformer is closed for the first time. When the target transformer is not closed for the first time, the stored historical action time deviation is obtained and used as the action time deviation of the corresponding circuit breaker of the target transformer.

[0093] In one feasible implementation, the closing execution module 30 is also used to collect the excitation current signal after closing; When the peak inrush current corresponding to the excitation current signal is greater than the preset current threshold, the target closing time is optimized.

[0094] The transformer adaptive closing device provided in this application, employing the transformer adaptive closing method in the above embodiments, can solve the technical problems of insufficient residual magnetism measurement accuracy and poor adaptability of closing strategies. Compared with the prior art, the beneficial effects of the transformer adaptive closing device provided in this application are the same as those of the transformer adaptive closing method provided in the above embodiments, and other technical features in the transformer adaptive closing device are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0095] This application provides a transformer adaptive closing device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the transformer adaptive closing method in the above embodiment 1.

[0096] The following is for reference. Figure 4The diagram illustrates a structural schematic suitable for implementing the transformer adaptive closing device in the embodiments of this application. The transformer adaptive closing device in the embodiments of this application may include, but is not limited to, mobile terminals such as mobile phones, laptops, digital radio receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Description), PMPs (Portable Media Players), vehicle terminals (e.g., vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. Figure 4 The transformer adaptive closing device shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this application.

[0097] like Figure 4 As shown, the transformer adaptive closing device may include a processing unit 1001 (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to a program stored in ROM (Read Only Memory) 1002 or a program loaded from storage device 1003 into RAM (Random Access Memory) 1004. RAM 1004 also stores various programs and data required for the operation of the transformer adaptive closing device. The processing unit 1001, ROM 1002, and RAM 1004 are interconnected via bus 1005. Input / output (I / O) interface 1006 is also connected to the bus. Typically, the following systems can be connected to I / O interface 1006: input devices 1007 including, for example, touch screens, touchpads, keyboards, mice, image sensors, microphones, accelerometers, gyroscopes, etc.; output devices 1008 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 1003 including, for example, magnetic tapes, hard disks, etc.; and communication devices 1009. Communication device 1009 allows the transformer adaptive closing device to communicate wirelessly or wiredly with other devices to exchange data. Although the figures show transformer adaptive closing devices with various systems, it should be understood that implementation or possession of all the systems shown is not required. More or fewer systems may be implemented alternatively.

[0098] Specifically, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from storage device 1003, or installed from ROM 1002. When the computer program is executed by processing device 1001, it performs the functions defined in the methods of the embodiments disclosed in this application.

[0099] The transformer adaptive closing device provided in this application, employing the transformer adaptive closing method in the above embodiments, can solve the technical problems of insufficient residual magnetism measurement accuracy and poor adaptability of closing strategies. Compared with the prior art, the beneficial effects of the transformer adaptive closing device provided in this application are the same as those of the transformer adaptive closing method provided in the above embodiments, and other technical features in this transformer adaptive closing device are the same as those disclosed in the previous embodiment method, and will not be repeated here.

[0100] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0101] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0102] This application provides a computer-readable storage medium having computer-readable program instructions (i.e., a computer program) stored thereon, the computer-readable program instructions being used to execute the transformer adaptive closing method in the above embodiments.

[0103] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0104] The aforementioned computer-readable storage medium may be included in the transformer adaptive closing device; or it may exist independently and not assembled into the transformer adaptive closing device.

[0105] The aforementioned computer-readable storage medium carries one or more programs. When these programs are executed by the transformer adaptive closing device, the transformer adaptive closing device: acquires the winding transient voltage signal during the opening process of the target transformer, performs numerical integration on the winding transient voltage signal to obtain the initial residual magnetism value of the target transformer; acquires the core leakage flux signal of the target transformer, performs complementary calibration on the initial residual magnetism value based on the core leakage flux signal to obtain the dynamic residual magnetism value of the target transformer; determines the target closing time based on the dynamic residual magnetism value of the target transformer, the type of the target transformer, and the type of the circuit breaker corresponding to the target transformer; and controls the circuit breaker to close the target transformer at the target closing time.

[0106] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0107] The modules described in the embodiments of this application can be implemented in software or hardware. The names of the modules do not necessarily limit the functionality of the unit itself.

[0108] The readable storage medium provided in this application is a computer-readable storage medium that stores computer-readable program instructions (i.e., a computer program) for executing the above-described adaptive closing method for transformers. This solves the technical problems of insufficient residual magnetism measurement accuracy and poor adaptability of the closing strategy. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this application are the same as those of the adaptive closing method for transformers provided in the above embodiments, and will not be elaborated upon here.

[0109] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the above-described transformer adaptive closing method.

[0110] The computer program product provided in this application can solve the technical problems of insufficient accuracy in residual magnetism measurement and poor adaptability of closing strategies. Compared with the prior art, the beneficial effects of the computer program product provided in this application are the same as those of the transformer adaptive closing method provided in the above embodiments, and will not be repeated here.

[0111] The above are only some embodiments of this application and do not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A transformer adaptive closing method, characterized in that, The method includes: The transient voltage signal of the winding during the opening process of the target transformer is acquired, and the initial residual magnetism value of the target transformer is obtained by numerical integration of the transient voltage signal of the winding. The core leakage flux signal of the target transformer is obtained, and the initial residual magnetism value is calibrated based on the core leakage flux signal to obtain the dynamic residual magnetism value of the target transformer. The target closing time is determined based on the dynamic residual magnetism value of the target transformer, the type of the target transformer, and the type of the circuit breaker corresponding to the target transformer. At the target closing time, the circuit breaker is controlled to close the target transformer.

2. The method as described in claim 1, characterized in that, The steps of acquiring the transient voltage signal of the winding during the opening process of the target transformer, and numerically integrating the transient voltage signal to obtain the initial residual magnetism value of the target transformer include: Acquire the transient voltage signal of the winding during the tripping process of the target transformer, determine the peak voltage time based on the transient voltage signal, and use the peak voltage time as the lower limit of integration; The target fitting model is obtained by fitting the transient voltage signal of the winding based on a preset attenuation model. Based on the target fitting model, the moment when the transient voltage reaches the steady-state zero value is taken as the upper limit of integration; Based on the upper and lower limits of integration, the transient voltage signal of the winding is numerically integrated to obtain the initial residual magnetism of the target transformer.

3. The method as described in claim 1, characterized in that, The step of determining the target closing time based on the dynamic residual magnetism value of the target transformer, the type of the target transformer, and the type of the circuit breaker corresponding to the target transformer includes: Based on the type of the target transformer, determine the pre-induced magnetic flux of the target transformer; The initial closing time is determined based on the dynamic residual magnetism of the target transformer, the pre-induced magnetic flux of the target transformer, and the type of the circuit breaker corresponding to the target transformer. The operating time deviation of the circuit breaker corresponding to the target transformer is determined, and the initial closing time is compensated based on the operating time deviation to obtain the target closing time.

4. The method as described in claim 3, characterized in that, The step of determining the initial closing time based on the dynamic residual magnetism of the target transformer, the pre-induced magnetic flux of the target transformer, and the type of circuit breaker corresponding to the target transformer includes: When the type of circuit breaker corresponding to the target transformer is a phase-operated circuit breaker, the steady-state flux amplitude is determined based on the pre-induced flux of the target transformer. Obtain the correspondence between dynamic residual magnetism, steady-state magnetic flux amplitude, grid frequency and initial closing time, and obtain the grid frequency; The initial closing time is determined based on the dynamic residual magnetism of the target transformer, the steady-state magnetic flux amplitude, the power grid frequency, and the corresponding relationship.

5. The method as described in claim 3, characterized in that, The step of determining the initial closing time based on the dynamic residual magnetism of the target transformer, the pre-induced magnetic flux of the target transformer, and the type of circuit breaker corresponding to the target transformer includes: When the type of circuit breaker corresponding to the target transformer is a three-phase linkage circuit breaker, the time when the total deviation is minimized is determined based on the pre-induced magnetic flux and dynamic residual magnetism of each phase of the target transformer. Based on the dynamic residual magnetism values ​​of each phase of the target transformer, the phase with the minimum residual magnetism is determined; At the moment when the total deviation is at its minimum, the flux matching moment corresponding to the phase with the minimum residual magnetism is determined, and the flux matching moment is taken as the initial closing moment.

6. The method as described in claim 3, characterized in that, The steps for determining the operating time deviation of the circuit breaker corresponding to the target transformer include: When the target transformer is closed for the first time, the operating time deviation of the circuit breaker corresponding to the target transformer is determined based on the type of the target transformer and the dynamic residual magnetism value of the target transformer. When the target transformer is not closed for the first time, the stored historical action time deviation is obtained and used as the action time deviation of the circuit breaker corresponding to the target transformer.

7. The method as described in claim 1, characterized in that, The step of controlling the circuit breaker to close the target transformer at the target closing time further includes: Collect the excitation current signal after the circuit breaker is closed; When the peak inrush current corresponding to the excitation current signal is greater than a preset current threshold, the target closing time is optimized.

8. A transformer adaptive closing device, characterized in that, The device includes: The residual magnetism measurement module is used to acquire the transient voltage signal of the winding during the opening process of the target transformer, and to perform numerical integration on the transient voltage signal of the winding to obtain the initial residual magnetism value of the target transformer. The residual magnetism measurement module is also used to acquire the core leakage magnetic field signal of the target transformer, and perform complementary calibration on the initial residual magnetism value based on the core leakage magnetic field signal to obtain the dynamic residual magnetism value of the target transformer. The closing control module is used to determine the target closing time based on the dynamic residual magnetism value of the target transformer, the type of the target transformer, and the type of the circuit breaker corresponding to the target transformer; The closing execution module is used to control the circuit breaker to close the target transformer at the target closing time.

9. A transformer adaptive closing device, characterized in that, The device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the transformer adaptive closing method as described in any one of claims 1 to 7.

10. A storage medium, characterized in that, The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, it implements the steps of the transformer adaptive closing method as described in any one of claims 1 to 7.

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