Transformer Inrush Current Identification Method and System Based on Sampling Value Image Space Distribution Characteristics

Abstract

The present invention relates to the field of power system relay protection and provides a transformer inrush current identification method and system based on the image space distribution characteristics of sampling values. The method introduces voltage and current sampling sequences, defines the concept of image space distribution of #imgabs0# sampling values, analyzes the image space distribution characteristics of #imgabs1# sampling values of transformers under different operating conditions, and proposes a transformer inrush current identification and fault closing identification criterion based on the image space distribution characteristics of #imgabs2# sampling values based on the symmetry and shape differences of the image space distribution. The current type of the transformer is identified according to the identification criterion, and the proposed method is simulated under different operating conditions of the transformer. The results show that the identification method proposed in the patent is accurate and reliable, can effectively identify inrush current, and prevent differential protection malfunction.

Description

Technical Field

[0001] The present invention relates to the field of power system relay protection, and more specifically, to a transformer inrush current identification method and system based on the spatial distribution characteristics of sampled value images. The method aims to accurately and quickly identify inrush currents in complex and diverse working conditions, effectively prevent the possibility of false operation or refusal of transformer current differential protection, and ensure rapid protection response and system stability. Background Art

[0002] As power systems continue to expand and become more intelligent, the monitoring and identification of inrush and fault currents in transformers, key equipment in power transmission and distribution networks, has become increasingly important. Transformers typically generate significant inrush currents when put into operation, which not only impacts normal equipment operation but can also cause damage and power system instability.

[0003] Therefore, accurately identifying inrush current and fault current is crucial to ensuring the safe and stable operation of the power system. Currently, research in this area has mainly proposed an adaptive second harmonic excitation inrush current braking scheme based on additional phase discrimination (Yuan Yubo, Lu Yuping, Li Cheng, et al. Research on an Adaptive Second Harmonic Excitation Inrush Current Braking Scheme Based on Additional Phase Discrimination [J]. Proceedings of the CSEE, 2006, 26(18):19-24.). However, this method has shortcomings in its anti-interference ability. When the excitation inrush current is large, the second harmonic content may be less than 15%, resulting in the inability of the differential protection to lock normally.

[0004] Another method is a method for identifying excitation inrush current and fault current based on a long short-term memory neural network (Zhang Guodong, Liu Kai, Pu Haitao, et al. Identification method of excitation inrush current and fault current based on a long short-term memory neural network [J]. Journal of Shanghai Jiao Tong University, 2024, 58(05): 730-738. DOI: 10.16183 / j.cnki.jsjtu.2022.352.), but this method has high computational complexity and may not be suitable for real-time or fast response scenarios. Summary of the Invention

[0005] To address the risk of failure of traditional second harmonic identification criteria when the transformer is switched on without load, the present invention provides a transformer inrush current identification method and system based on the spatial distribution characteristics of sampled value images.

[0006] According to a first aspect of the present invention, there is provided a transformer inrush current identification method based on spatial distribution characteristics of sampled values, comprising:

[0007] Collect the current sequence of the primary side of the transformer and voltage sequence ;

[0008] Based on the current sequence collected and the voltage sequence , build The sampled values are spatially distributed, wherein the current sequence The x-axis is the voltage series Establish a coordinate system for the y-axis;

[0009] according to The sampling values are used to identify the current type of the transformer based on the spatial distribution characteristics, where the current type includes normal current, inrush current and fault current.

[0010] According to a second aspect of the present invention, there is provided a transformer inrush current identification system based on spatial distribution characteristics of sampled values, comprising:

[0011] Acquisition module, used to collect the current sequence of the primary side of the transformer and voltage sequence ;

[0012] Building blocks for acquiring the current sequence based on and the voltage sequence , build The sampled values are spatially distributed, wherein the current sequence The x-axis is the voltage series Establish a coordinate system for the y-axis;

[0013] Identification module, used to The sampling values are used to identify the current type of the transformer based on the spatial distribution characteristics, where the current type includes normal current, inrush current and fault current.

[0014] The present invention provides a transformer inrush current identification method and system based on the spatial distribution characteristics of the sampling value image, which is based on the transformer in different operating conditions. The sampling value image spatial distribution characteristics are different and based on The transformer inrush current identification and closing-to-fault identification criteria based on the spatial distribution characteristics of the sampling value image are used to solve the failure risk of the traditional second harmonic identification criteria when the transformer is closed under no-load conditions, thereby improving the reliability of protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A flow chart of a transformer inrush current identification method based on spatial distribution characteristics of sampled values provided by the present invention;

[0016] Figure 2 Schematic diagram of the transformer inrush current identification method of the present invention;

[0017] Figure 3When the transformer is operating normally Schematic diagram of the spatial distribution of sample values;

[0018] Figure 4 When the transformer is in fault state Schematic diagram of the spatial distribution of sample values;

[0019] Figure 5 (a) shows the asymmetric surge flow Schematic diagram of the spatial distribution of sample values;

[0020] Figure 5(b) shows the symmetrical surge flow. Schematic diagram of the spatial distribution of sample values;

[0021] Figure 5 (c) shows the fault closing Schematic diagram of the spatial distribution of sample values;

[0022] Figure 6 (a) shows the current and voltage waves of phase A of the Y / △ transformer during normal operation;

[0023] Figure 6 (b) Phase A of the Y / △ transformer during normal operation Schematic diagram of the spatial distribution of sample values;

[0024] Figure 7 (a) shows the waveforms of the current and voltage of phase A of the Y / △ transformer when the closing angle is 0°;

[0025] Figure 7 (b) shows the Y / △ transformer phase A when the closing angle is 0° Schematic diagram of the spatial distribution of sample values;

[0026] Figure 8 Schematic diagram of the second harmonic content of phase A of the Y / △ transformer when the closing angle is 90°;

[0027] Figure 9 (a) shows the waveforms of the current and voltage on phase A of the Y / △ transformer when a phase A ground fault occurs;

[0028] Figure 9 (b) shows the Y / △ transformer when a phase A ground fault occurs Schematic diagram of the spatial distribution of sample values;

[0029] Figure 10 (a) shows the waveforms of the current and voltage on phase A of the Y / △ transformer when the circuit breaker is closed due to a phase A ground fault.

[0030] Figure 10 (b) shows the Y / △ transformer when the circuit breaker is closed with a phase A ground fault. Schematic diagram of the spatial distribution of sample values;

[0031] Figure 11 Schematic diagram of the second harmonic content of phase A of the Y / △ transformer when the circuit breaker is closed due to a phase A ground fault;

[0032] Figure 12This is a structural block diagram of a transformer inrush current identification system based on the spatial distribution characteristics of sampled value images provided by the present invention. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. In addition, the technical features in the various embodiments or single embodiments provided by the present invention can be arbitrarily combined with each other to form a feasible technical solution. This combination is not restricted by the sequence of steps and / or structural composition mode, but must be based on the ability of ordinary technicians in this field to implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0034] Figure 1 The present invention provides a flow chart of a transformer inrush current identification method based on the spatial distribution characteristics of the sampled value image, as shown in FIG. Figure 1 and Figure 2 As shown, the method includes:

[0035] Step 1: Collect the current sequence of the primary side of the transformer and voltage sequence .

[0036] It is understandable that when it is necessary to identify the current type of the transformer, the current sequence of the primary side of the transformer over a period of time is collected. and voltage sequence .

[0037] Step 2: Based on the collected current sequence and the voltage sequence , build The sampled values are spatially distributed, wherein the current sequence The x-axis is the voltage series Create a coordinate system for the y-axis.

[0038] It is understandable that step 1 collects the current sequence of the primary side of the transformer over a period of time. and voltage sequence Considering the different amplitudes of voltage and current in different states, the voltage sequence and current sequence are normalized according to the rated value. and voltage sequence ,definition The sample value image space is distributed in a rectangular coordinate space, with the vertical axis being the voltage The sampling sequence of the horizontal axis is the current The sampling sequence.

[0039] Step 3, according to The sampling values are used to identify the current type of the transformer based on the spatial distribution characteristics, where the current type includes normal current, inrush current and fault current.

[0040] It is understandable that according to The sampling value image spatial distribution characteristics are used to judge the transformer working current type. Before this, the current sequence of the transformer under different known operating conditions is collected. and voltage sequence , and construct each known operating condition The spatial distribution of sample values; based on each known operating condition The spatial distribution of the sampled values is analyzed to analyze the transformer under each known operating condition. The sampling value image spatial distribution characteristics, the operating conditions of the transformer include the normal operating condition of the transformer, the fault operating condition of the transformer and the no-load closing operating condition of the transformer.

[0041] Among them, when the transformer is operating normally, the load impedance is basically constant. The spatial distribution of the sampled values is an ellipse symmetrical about the X-axis and the Y-axis with a small difference in the long and short radii, such as Figure 3 As shown, since factors such as the size of the load and the rated capacity of the transformer will affect the size of the per-unit current value, the width of the formed ellipse will also change.

[0042] When the transformer fails, the load impedance becomes a short-circuit impedance. The spatial distribution of the sampled values is no longer an ellipse symmetrical about the X-axis and the Y-axis, but an ellipse with a large difference in long and short radii that tilts toward the first and third quadrants, such as Figure 4 As shown. Under different fault types, the magnitude of the fault current will change, resulting in The sampling value changes as the size of the current per unit value in the spatial distribution.

[0043] When the transformer is closed at no-load, an asymmetric inrush current or a symmetric inrush current will be generated on the primary side of the transformer. The spatial distribution of the sampled values is an irregular semi-ellipse and symmetrical about the X axis, as shown in Figure 5 (a). When a symmetrical inrush current is generated, the transformer The spatial distribution of the sampling value is a long-necked bottle shape symmetrical about the Y axis, as shown in Figure 5 (b). Since the asymmetric inrush current is affected by the closing angle, the amplitude of the asymmetric inrush current will change under different closing angles, resulting in The size of the current per unit value in the image space distribution of the sampling value will change, but its image space distribution is symmetrical about the X axis; if the transformer is closed with a fault, the transformer The spatial distribution of the sampling values is mainly in the first and third quadrants, forming an irregular graph that is not symmetrical about the X-axis and the Y-axis, as shown in Figure 5 (c). When closing the circuit breaker under different fault types, the magnitude of the fault current will change, resulting in The sampling value changes as the size of the current per unit value in the spatial distribution.

[0044] By analyzing the transformer under different operating conditions The spatial distribution of the sampling values is analyzed to obtain the transformer under different operating conditions. The spatial distribution characteristics of the sampling values can be compared to see the transformers under different working conditions. The spatial distribution characteristics of the sampling values are different. The current and inrush current during normal operation of the transformer are symmetrical, while the fault current is not symmetrical.

[0045] Based on this, according to the current sequence of the primary side of the transformer collected in steps 1 and 2 and voltage sequence The spatial distribution characteristics of the transformer are used to identify the current working state of the transformer.

[0046] Specifically, the primary side of the transformer constructed according to step 2 The sampling value is distributed in space, and the transformer is calculated respectively. The sampling values are distributed in the area enclosed by the first, second, third, and fourth quadrants and the X and Y axes. 、 、 、 ; and respectively calculate the transformer The sampling values are distributed in the area enclosed by the positive X-axis and the Y-axis, the negative X-axis and the Y-axis, the positive Y-axis and the X-axis, and the negative Y-axis and the X-axis. 、 、 、 .according to 、 、 、 as well as 、 、 、 The size relationship between them can be used to identify the current type of the transformer.

[0047] Among them, the normal current identification criterion of the transformer is constructed. When the transformer operates normally, according to the symmetry of the ellipse, its image space distribution satisfies formula (1):

[0048] (1)

[0049] In the formula, S1, S2, S3, and S4 represent The sampling values are distributed in the area enclosed by the first, second, third, and fourth quadrants and the X-axis and Y-axis; Expressed as The sampling values are distributed in the area enclosed by the positive X-axis and the Y-axis; Expressed as The sampling values are distributed in the area enclosed by the negative X-axis and the Y-axis; Expressed as The sampling values are distributed in the area enclosed by the positive Y axis and the X axis; Expressed as The area where the sample values are distributed on the negative Y-axis and the area enclosed by the X-axis. 、 are respectively expressed as the threshold value of area difference.

[0050] Similarly, the transformer inrush current identification criterion is constructed. When the transformer is closed under no-load conditions, at least one of the symmetrical inrush currents or asymmetrical inrush currents is symmetrical about the X-axis or the Y-axis, and its spatial distribution satisfies equation (2). This criterion blocks the transformer current differential protection to prevent false operation of the no-load closing protection.

[0051] (2)

[0052] Similarly, the fault identification criterion of the transformer is constructed. When the transformer fails or is closed at no-load, the fault image space is distributed in an irregular pattern and does not satisfy equation (1) or equation (2). When this criterion is combined with the transformer current differential protection, the lock is released.

[0053] The present invention is based on the different operating conditions of the transformer The spatial distribution characteristics of the sampled values are used to construct the identification criteria for the normal current, inrush current and fault current of the transformer. According to the criteria for different current working types, the current working state of the transformer is identified.

[0054] The transformer inrush current identification method based on the spatial distribution characteristics of the sampled value image provided by the present invention is verified by simulation below.

[0055] Using PSCAD, a set of converter transformer models was constructed. Two transformers were connected in Y / △ and Y / Y configurations, respectively. The internal parameters of the transformers were identical. Each converter transformer had a capacity of 732.3 MVA and a transformation ratio of 525 kV / 286.8 kV. The rated voltages of the Y / Y and Y / △ transformers were (525 / √3) / 165.59 kV and (525 / √3) / (165.59 / √3) kV, respectively. Simulations were performed for normal system operation, no-load closing, fault conditions, and closing with a fault. Phase A was used as an example for all operating conditions.

[0056] Example 1: Assume that two transformers are operating normally. The waveforms of the current and voltage of phase A of the Y / △ transformer are shown in Figure 6(a). The spatial distribution of the sampled values is shown in Figure 6(b). As shown in Figure 6(b), S1, S2, S3, and S4 satisfy Equation (1), and ; , so it is identified as normal current.

[0057] Example 2: Set the commutation transformers to be closed at no-load at 1.0167s, that is, the closing angle of phase A is 0°, and the residual magnetism of both transformers is 0. At this time, the waveforms of the current and voltage of phase A of the Y / △ transformer are shown in Figure 7(a). The spatial distribution of the sampled values is shown in Figure 7(b). As shown in Figure 7(b), S1, S2, S3, and S4 satisfy Equation (2), where ; Therefore, it is identified as an asymmetric inrush current and the differential protection is blocked. Table 1 shows the identification results under different closing angles, and all of them can be accurately identified as inrush current.

[0058] Table 1 Recognition results at different closing angles

[0059]

[0060] As shown in Table 1, when the closing angle is 90°, the Y / △ transformer A phase generates a symmetrical inrush current. Figure 8 The figure shows the second harmonic content in this case. It can be seen that the second harmonic content is higher than 15% from 1.05s to 1.07s, and is less than 15% in the rest of the time period. The second harmonic restraint is unlocked, and the differential protection malfunctions. Therefore, the traditional second harmonic restraint method cannot accurately identify the inrush current.

[0061] Example 3: Assume that a ground fault occurs on phase A of the Y / △ transformer at 1s. The waveforms of the current and voltage on phase A of the Y / △ transformer are shown in Figure 9(a). The spatial distribution of the sampled values is shown in Figure 9(b). As shown in Figure 9(b), S1, S2, S3, and S4 do not satisfy equations (1) and (2). ; ; ; , so it is identified as fault current at this time, and the differential protection is activated. Table 2 shows the identification results of different faults occurring after the transformer is in normal operation. All faults can be accurately identified as fault current.

[0062] Table 2 Identification results of different faults after normal operation

[0063]

[0064] Example 4: Assume that the Y / △ transformer is closed with a fault at 1.0167s. The fault type is a ground fault of phase A. The waveforms of the current and voltage of phase A of the Y / △ transformer are shown in Figure 10(a). The spatial distribution of the sampled values is shown in Figure 10(b). As shown in Figure 10(b), S1, S2, S3, and S4 do not satisfy Equation (1) and Equation (2). ; ; ; At this time, it is identified as a fault current and the differential protection is activated. Figure 11 The second harmonic content under this operating condition is shown in Table 3. It can be seen that the second harmonic content is higher than 15% between 1.0167s and 1.16s. At this time, the differential protection refuses to operate, so the traditional second harmonic restraint method cannot accurately identify the inrush current. Table 3 shows the identification results when closing the circuit breaker with different faults, all of which can be accurately identified as fault current.

[0065] Table 3 Identification results of closing circuit breaker with different faults

[0066]

[0067] See also Figure 12 , a transformer inrush current identification system based on the spatial distribution characteristics of sampled values provided by the present invention, comprising:

[0068] Acquisition module 1201, used to collect the current sequence of the primary side of the transformer and voltage sequence ;

[0069] Building module 1202, for collecting the current sequence and the voltage sequence , build The sampled values are spatially distributed, wherein the current sequence The x-axis is the voltage series Establish a coordinate system for the y-axis;

[0070] Identification module 1203, for The sampling values are used to identify the current type of the transformer based on the spatial distribution characteristics, and the current type includes normal current, inrush current and fault current.

[0071] It can be understood that the transformer inrush current identification system based on the spatial distribution characteristics of the sampled value image provided by the present invention is different from the transformer inrush current identification system based on the spatial distribution characteristics of the sampled value image provided by the above embodiments. The transformer inrush current identification method based on the spatial distribution characteristics of the sampling value image is The relevant technical features of the transformer inrush current identification system based on the spatial distribution characteristics of the sampling value image can be referred to The relevant technical features of the transformer inrush current identification method based on the spatial distribution characteristics of the sampling value image are not repeated here.

[0072] The present invention provides a method based on The transformer inrush current identification method and system based on the spatial distribution characteristics of sampled values have the following beneficial effects:

[0073] (1) Introduce the voltage and current sampling sequence and define The concept of spatial distribution of sampling values is used to analyze the transformer under different working conditions. The image space distribution characteristics of the sampling values are proposed based on their symmetry and the shape difference of the image space distribution. The identification criteria for transformer inrush current and closing-on-fault based on the spatial distribution characteristics of the sampling value image are used. The current type of the transformer is identified according to the identification criteria. The proposed method is simulated for different transformer operating conditions. The results show that the identification method proposed in this patent is accurate and reliable, can effectively identify inrush current, and can solve the failure risk of traditional second harmonic identification criteria when the transformer is closed at no-load, effectively prevent the possibility of false operation or refusal of differential protection, and ensure the rapid response of protection and system stability.

[0074] (2) According to the transformer under different working conditions The spatial distribution characteristics of the sampling values can accurately and quickly identify the inrush current of the transformer and are suitable for complex and diverse working environments.

[0075] It should be noted that, in the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0076] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0077] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts 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, a special-purpose computer, an embedded computer, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0078] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0079] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0080] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0081] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A transformer inrush current identification method based on the spatial distribution characteristics of sampled values, characterized in that: include: Collect the current sequence of the primary side of the transformer and voltage sequence ; Based on the current sequence collected and the voltage sequence , build The sampled values are spatially distributed, wherein the current sequence The x-axis is the voltage series Establish a coordinate system for the y-axis; according to The sampling value image spatial distribution characteristics are used to identify the current type of the transformer, including normal current, inrush current and fault current; The basis The sampling value image spatial distribution characteristics are used to identify the current type of the transformer, including: The current sequence of the transformer and the voltage sequence Standardize according to rated value; Calculate the transformer The sampling values are distributed in the area enclosed by the first, second, third, and fourth quadrants and the X and Y axes. 、 、 、 , and respectively calculate the transformer The sampling values are distributed in the area enclosed by the positive X-axis and the Y-axis, the negative X-axis and the Y-axis, the positive Y-axis and the X-axis, and the negative Y-axis and the X-axis. 、 、 、 ; according to 、 、 、 as well as 、 、 、 The size relationship between them is used to identify the current type of the transformer; The basis 、 、 、 as well as 、 、 、 The size relationship between them is used to identify the current type of the transformer, including: when 、 、 、 as well as 、 、 、 When the equation (1) is satisfied between the two, the current type of the transformer is normal current; where: (1) Where, 、 They are respectively expressed as the threshold of area difference; when 、 、 、 as well as 、 、 、 When the equation (2) is satisfied between the two, the current type of the transformer is inrush current, where: （2） when 、 、 、 as well as 、 、 、 When the equation (1) or (2) is not satisfied between them, the current type of the transformer is a fault current.

2. The transformer inrush current identification method according to claim 1, characterized in that: The basis The spatial distribution characteristics of the sampled values are used to identify the current type of the transformer, which previously included: Collect the current sequence of the transformer under different known operating conditions and voltage sequence , and construct each known operating condition Sample value image spatial distribution; Based on each known operating condition The spatial distribution of the sampled values is analyzed to analyze the transformer under each known operating condition. The sampling value image spatial distribution characteristics, the operating conditions of the transformer include the normal operating condition of the transformer, the fault operating condition of the transformer and the no-load closing operating condition of the transformer.

3. The transformer inrush current identification method according to claim 2, characterized in that: When the transformer is in normal operation, the load impedance is substantially constant. The spatial distribution of the sampling values is an ellipse that is symmetrical about the X-axis and the Y-axis with a small difference in long and short radii.

4. The transformer inrush current identification method according to claim 2, characterized in that: When the transformer is in fault operation, the load impedance becomes a short-circuit impedance. The spatial distribution of the sampling values is an ellipse with a large difference in long and short radii that is inclined toward the first and third quadrants.

5. The transformer inrush current identification method according to claim 2, characterized in that: When the transformer is in no-load closing operation, an asymmetric inrush current or a symmetric inrush current is generated on the primary side of the transformer; wherein: When an asymmetrical inrush current occurs, the transformer The sampling value image space distribution is an irregular semi-ellipse and is symmetrical about the X axis; when a symmetrical inrush current is generated, the transformer The spatial distribution of the sampled values is in the shape of a long-necked flask symmetrical about the Y axis; If the transformer is closed with a fault, the transformer The spatial distribution of the sampling values is mainly an irregular figure in the first and third quadrants that is not symmetrical about the X-axis and the Y-axis.

6. A transformer inrush current identification system based on spatial distribution characteristics of sampled value images, used to implement the transformer inrush current identification method based on spatial distribution characteristics of sampled value images as described in any one of claims 1 to 5, characterized in that: include: Acquisition module, used to collect the current sequence of the primary side of the transformer and voltage sequence ; Building blocks for acquiring the current sequence based on and the voltage sequence , build The sampled values are spatially distributed, wherein the current sequence The x-axis is the voltage series Establish a coordinate system for the y-axis; Identification module, used to The sampling values are used to identify the current type of the transformer based on the spatial distribution characteristics, and the current type includes normal current, inrush current and fault current.

Images