Saturation fault identification method, device and equipment of current transformer and medium

Abstract

The embodiment of the invention discloses a saturation fault identification method and device of a current transformer, equipment and a medium, and relates to the technical field of current transformers. The method comprises the following steps: if it is determined that a short-circuit fault occurs in a target line, obtaining target current data detected by a target current transformer after the fault occurrence time; the target current transformer is used for detecting the current of a target line; respectively calculating the similarity between the target current data and the fault current data under various saturation fault conditions; fault occurrence moments and / or fault occurrence positions are different under different saturation fault conditions; and determining a saturation fault detection result of the target current transformer according to a similarity calculation result. According to the technical scheme, the similarity between the target current data after short circuit and the fault current data is calculated, whether the target current transformer has the saturation fault can be determined according to the similarity calculation result, and support is provided for safe operation of the power distribution network.

Description

Technical Field

[0001] The present invention relates to the technical field of current transformers, and in particular to a method, device, equipment and medium for identifying a saturation fault of a current transformer. Background Art

[0002] The current transformer of the distribution network can provide real-time and accurate detection of the current information of the line. In scenarios such as line protection and special protection of large equipment, current information needs to be obtained through current transformers. Current transformers are an important guarantee for the accurate execution of various relay protection equipment.

[0003] When a current transformer has a saturation fault, the current information output by the current transformer to the protection device will be distorted, which will directly or indirectly trigger the switch to trip, affecting the power supply reliability of the entire distribution network. How to identify whether a current transformer has a saturation fault is a technical problem that needs to be solved urgently. Summary of the invention

[0004] The present invention provides a method, device, equipment and medium for identifying a saturation fault of a current transformer, which can accurately identify whether a saturation fault exists in the current transformer.

[0005] According to one aspect of the present invention, a method for identifying a saturation fault of a current transformer is provided, the method comprising:

[0006] If it is determined that a short circuit fault occurs in the target line, then obtaining target current data detected by a target current transformer after the fault occurs; the target current transformer is used to detect the current of the target line;

[0007] The similarities between the target current data and the fault current data under various saturation fault conditions are calculated respectively; the fault occurrence time and / or fault occurrence location under different saturation fault conditions are different;

[0008] According to the similarity calculation result, the saturation fault detection result of the target current transformer is determined.

[0009] According to another aspect of the present invention, a saturation fault identification device for a current transformer is provided, comprising:

[0010] A target current data acquisition module, used for acquiring target current data detected by a target current transformer after the fault occurs if it is determined that a short circuit fault occurs in the target line; the target current transformer is used for detecting the current of the target line;

[0011] A similarity calculation module is used to respectively calculate the similarity between the target current data and the fault current data under various saturation fault conditions; the fault occurrence time and / or fault occurrence location under different saturation fault conditions are different;

[0012] The saturation fault detection result determination module is used to determine the saturation fault detection result of the target current transformer according to the similarity calculation result.

[0013] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising:

[0014] at least one processor; and

[0015] a memory communicatively connected to the at least one processor; wherein,

[0016] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the saturation fault identification method of the current transformer described in any embodiment of the present invention.

[0017] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the current transformer saturation fault identification method described in any embodiment of the present invention when executed.

[0018] The technical solution of the embodiment of the present application includes: if it is determined that a short circuit fault occurs in the target line, then the target current data detected by the target current transformer after the fault occurs is obtained; the target current transformer is used to detect the current of the target line; the similarity between the target current data and the fault current data under various saturation fault conditions is calculated respectively; the fault occurrence time and / or fault occurrence location under different saturation fault conditions are different; according to the similarity calculation result, the saturation fault detection result of the target current transformer is determined. By calculating the similarity between the target current data after the short circuit and the fault current data, the technical solution can determine whether a saturation fault occurs in the target current transformer according to the similarity calculation result, thereby providing support for the safe operation of the distribution network.

[0019] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1This is a flow chart of a method for identifying a saturation fault of a current transformer provided in accordance with the first embodiment of the present application;

[0022] Figure 2 is a flow chart of a method for identifying a saturation fault of a current transformer provided in accordance with the second embodiment of the present application;

[0023] Figure 3 A current transformer saturation fault analysis model is provided according to the second embodiment of the present application;

[0024] Figure 4 It is a structural schematic diagram of a saturation fault identification device for a current transformer provided according to Embodiment 3 of the present application;

[0025] Figure 5 It is a structural schematic diagram of an electronic device for implementing a saturation fault identification method of a current transformer according to an embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme 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 only embodiments of a part of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0027] It should be noted that the terms "first", "second", "target", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0028] Embodiment 1

[0029] Figure 1A flowchart of a method for identifying a saturation fault of a current transformer is provided for the first embodiment of the present application. The embodiment of the present application can be applied to the case of detecting a saturation fault of a current transformer. The method can be performed by a saturation fault identification device for a current transformer. The saturation fault identification device for a current transformer can be implemented in the form of hardware and / or software. The saturation fault identification device for a current transformer can be configured in an electronic device with data processing capabilities. Figure 1 As shown, the method includes:

[0030] S110: If it is determined that a short circuit fault occurs in the target line, then target current data detected by the target current transformer after the fault occurs is obtained.

[0031] Among them, the target line can be a line in the distribution network, such as a feeder in a three-phase circuit. Normally, if a short-circuit fault occurs in the target line, the target current transformer detects that the current is too large, and sends the detected current information to the circuit protection device, etc., for short-circuit protection; however, if a saturation fault occurs in the target current transformer, even if the target line has returned to normal, the target current transformer cannot detect the actual current of the target line due to the saturation fault, and still outputs a fault current detection result, so that some overcurrent protection devices are operated, resulting in the target line being unable to operate normally. Therefore, whether the current transformer can be accurately identified as having a saturation fault is of great significance to the normal operation of the power grid. Since the saturation fault of the current transformer is usually caused by a line short circuit, the technical solution of the embodiment of the present application identifies the saturation fault of the target current transformer after the target line is short-circuited. The target current transformer is used to detect the current of the target line. The target current data is time series data, which includes multiple target current values.

[0032] Specifically, in one scenario, if the fault warning light is triggered, it is determined that a short circuit fault has occurred in the target line, and then the target current data detected by the target current transformer after the fault occurs is obtained through the current sampling device. In another scenario, if the staff finds that the target line has a short circuit, the short circuit information is sent to the saturation fault identification device of the current transformer described in the embodiment of the present application. Since the current sampling device always samples the current of the target current transformer, which records the current data of the previous period of time, the target current data detected by the target current transformer after the fault occurs in the current sampling device can be read.

[0033] In an embodiment of the present application, optionally, the process of determining the fault occurrence time includes: obtaining detection current data of the target current transformer in a target time period; the target time period includes the time when the short-circuit fault of the target line occurs; in the detection current data, determining a target current value that meets the current jump condition; and determining the sampling time corresponding to the target current value as the fault occurrence time.

[0034] Specifically, since it is usually determined that the target line has a short circuit fault, the fault occurrence time is before the current time, so it is necessary to determine the accurate fault occurrence time based on the detection current data of the target time period. Regarding the determination process of the target time period, after receiving the target line short circuit fault at the current time, the time period of the preset time length before the current time and the preset time length after the current time are determined as the target time period.

[0035] Furthermore, after determining the target time period, the current sampling device obtains the detection current data detected by the target current transformer within the target time period, which is time series data. Since the short circuit of the target line will cause the current jump, each current value is identified in the detection current data to obtain the target current value that meets the current jump condition, and the sampling time corresponding to the target current value is determined as the fault occurrence time.

[0036] In an embodiment of the present application, optionally, in the detection current data, a target current value that satisfies the current jump condition is determined, including: traversing the detection current values ​​in the detection current data, and calculating the difference between the current detection current value and the reference detection current value; the sampling time of the reference current value is one power frequency cycle before the sampling time of the current detection current value; if the absolute value of the difference calculation result is greater than a preset current threshold, then determining that the current detection current value is the target current value.

[0037] The power frequency cycle is the cycle of alternating current, which is usually 50 Hz.

[0038] Exemplarily, after the detection current data is obtained, the detection current values ​​therein are traversed in sequence, and it is determined whether the current detection current value is the target current value according to the following formula:

[0039]

[0040] Among them, I N (j) is the current detection current value, j is the number of the detection current value, is the reference current value, f s is the sampling frequency, is the number of samples in one power frequency cycle, I set is the preset current threshold.

[0041] This scheme is configured so that after a short-circuit fault occurs, the target time period including the time when the short-circuit fault occurs can be accurately locked, and then based on the detected current data of the target time period and the specific circumstances of the current mutation, the target current value when the short circuit occurs can be identified. The sampling time of the target current value is the short-circuit time, thereby achieving the effect of accurately determining the short-circuit time.

[0042] S120, respectively calculating similarities between the target current data and the fault current data under various saturation fault conditions.

[0043] Among them, the fault current data under various saturation fault conditions are pre-generated, and each fault current data corresponds to a current transformer saturation fault condition. The fault occurrence time and / or fault occurrence location under different saturation fault conditions are different, that is: the fault current data when the fault occurs at 500 meters and at 400 meters of the current transformer are different; in the same power frequency cycle, if the fault occurs at different times, the fault current data are different.

[0044] Specifically, the fault current data can be obtained in advance under various fault conditions, and after obtaining the target current data, the similarity between the target current data and the fault current data under various saturation fault conditions is calculated to distinguish the subsequent saturation fault. Exemplarily, when performing the similarity calculation, the cosine similarity of the target current data and the fault current data can be calculated.

[0045] In the embodiment of the present application, optionally, calculating the similarity between the target current data and the fault current data includes: normalizing the fault current data to obtain normalized fault current data; and determining the similarity between the target current data and the fault current data based on the following formula:

[0046]

[0047] Where cosk is the similarity between the target current data and the fault current data under the kth saturation fault condition, I n (j) is the target current data, I' 2k (j) is the fault current data under the kth saturation fault condition, is the number of current values ​​included in the current data, and j is the number of the current value.

[0048] Specifically, the fault current data and the target current data may be normalized, and similarity calculation may be performed on the normalized data. For example, the fault current data may be normalized by the following formula:

[0049]

[0050] Among them, I' 2k(j) is the normalized fault current data under the kth fault condition, I 2k (j) is the fault current data under the kth fault condition, j is the number of the fault current value in the fault current data, I 2k_min is the minimum value of the fault current data under the kth fault condition, I 2k_max is the maximum value of the fault current data under the kth fault condition.

[0051] S130, determining a saturation fault detection result of the target current transformer according to the similarity calculation result.

[0052] Specifically, after obtaining the similarity calculation results, if the similarities are less than or equal to the preset similarity threshold, it can be determined that the target current data and the fault current data are not similar, and it can be determined that the target current transformer has not had a saturation fault; if the similarity between the target current data and the target fault current data is greater than the preset similarity threshold, it can be determined that a saturation fault exists in the target current data, and the fault location of the saturation fault is the fault location of the target fault current data.

[0053] Exemplarily, the similarity threshold is 0.9.

[0054] In the embodiment of the present application, the method further includes: after obtaining the similarity calculation result, if the similarities are all less than or equal to the preset similarity threshold, traversing the detection current values ​​in the detection current data in turn, and judging whether the current detection current value is the target current value according to the following formula:

[0055]

[0056] If multiple target current values ​​are determined, the multiple target current values ​​are respectively determined as the fault occurrence time, and then the target current data after the multiple fault occurrence times are respectively obtained, and the similarity calculation of the target current data and the fault current data is performed again. The process is the same as the above process, and it is re-determined whether the target current transformer has a saturation fault. Furthermore, if multiple fault occurrence times are obtained, three fault occurrence times before and after the first determined fault occurrence time are selected for subsequent calculations. This scheme is set up in this way, and fault saturation can be detected multiple times to avoid missed detection.

[0057] The technical solution of the embodiment of the present application includes: if it is determined that a short circuit fault occurs in the target line, then the target current data detected by the target current transformer after the fault occurs is obtained; the target current transformer is used to detect the current of the target line; the similarity between the target current data and the fault current data under various saturation fault conditions is calculated respectively; the fault occurrence time and / or fault occurrence location under different saturation fault conditions are different; according to the similarity calculation result, the saturation fault detection result of the target current transformer is determined. By calculating the similarity between the target current data after the short circuit and the fault current data, the technical solution can determine whether a saturation fault occurs in the target current transformer according to the similarity calculation result, thereby providing support for the safe operation of the distribution network.

[0058] Embodiment 2

[0059] Figure 2 This is a flow chart of a method for identifying a saturation fault of a current transformer provided in Embodiment 2 of the present application. Embodiment 2 of the present application is optimized based on the above embodiment.

[0060] like Figure 2 As shown, the method of the embodiment of the present application specifically includes the following steps:

[0061] S210, acquiring detection current data of a target current transformer in a target time period; the target time period includes a time when a short circuit fault of a target line occurs.

[0062] S220, determining a target current value that satisfies a current jump condition in the detected current data.

[0063] S230, determining the sampling time corresponding to the target current value as the fault occurrence time.

[0064] S240: If it is determined that a short circuit fault occurs in the target line, then target current data detected by the target current transformer after the fault occurs is obtained.

[0065] In an embodiment of the present application, optionally, a process for determining fault current data in a saturation fault situation includes: starting from the time when the fault occurs, determining the fault current value of the secondary side of the current transformer at each time point within an industrial frequency cycle according to the line information that can trigger the current transformer saturation fault; determining the time series fault current data according to the fault current value at each time point.

[0066] For example, when generating fault current data, relevant data can be obtained through power system simulation software, and the following can be established in the power system simulation software: Figure 3The current transformer saturation fault analysis model shown sets the current in the line to 80% of the rated current of the current transformer. This setting makes it possible to cause a saturation fault of the current transformer when a short circuit occurs in the line due to the large current. A short circuit fault is set at the fault point F. From the moment of the fault, the fault current value of the secondary side of the current transformer at each time point within a power frequency cycle is determined according to the line information that can trigger the current transformer saturation fault; the fault current values ​​at each time point are sorted to obtain the fault current data of the time series. It should be noted that the number of fault current values ​​is the number that can be obtained by sampling within a power frequency cycle. For example, if the power frequency cycle is 50 Hz and the sampling frequency is 5000 Hz, that is, 5000 samples are sampled per second, the number of fault current values ​​is 100.

[0067] In an embodiment of the present application, optionally, the fault current value on the secondary side of the current transformer is determined based on line information that can trigger a current transformer saturation fault, including: determining the fault current value on the secondary side of the current transformer based on the current transformer transformation ratio, three-phase fault steady-state current amplitude, power frequency, sampling frequency, fault fundamental initial phase, non-periodic component amplitude and attenuation time constant.

[0068] In the embodiment of the present application, optionally, the fault current value on the secondary side of the current transformer is determined according to the current transformer ratio, the three-phase fault steady-state current amplitude, the power frequency, the sampling frequency, the initial phase of the fault fundamental wave, the amplitude of the non-periodic component and the decay time constant, including:

[0069] Determine the fault current value on the secondary side of the current transformer according to the following formula:

[0070]

[0071] Among them, I 2 (j) is the fault current value on the secondary side of the current transformer, K is the current transformer ratio, I M is the three-phase fault steady-state current amplitude, f n is the power frequency, t(j) is the jth time point, j is the number of the time point, f s is the sampling frequency, is the initial phase of the fault fundamental wave, k 0 is the amplitude of the non-periodic component, and τ is the decay time constant. M It is related to the location of the fault point F. Related to the fault time, k 0 with I M and τ is related to the impedance value from the short-circuit point to the power supply.

[0072] Further, after obtaining the fault current data under one fault condition, the fault occurrence time and / or fault occurrence location are changed to obtain the fault current data under various fault conditions. For example, when changing the fault occurrence location, the fault occurrence location can be moved from the beginning of the line, with an interval of 500m each time until the end of the line. When changing the fault occurrence time, the fault occurrence location can be moved with an interval of one sampling period each time. Total changes For example, if the sampling frequency is 5000 Hz, that is, 5000 samples are taken in one second, and the interval between two adjacent samples is 0.0002 seconds, then the fault occurrence time can be changed by delaying 0.0002 seconds each time. Since the samples are taken 100 times in one power frequency cycle, the total number of times the fault occurrence time is changed is 100 times.

[0073] This scheme is set up in this way to obtain fault current data under almost all fault conditions, so that after the similarity between the target current data and the fault current data is subsequently measured, if there is no similar fault current data, it can be determined that there is no saturation fault.

[0074] Exemplarily, after obtaining the fault current data under various fault conditions, each fault current data may be recorded as a row in a matrix, and the obtained matrix is ​​as follows:

[0075]

[0076] Each row is fault current data under a fault condition.

[0077] S250, respectively calculating similarities between the target current data and the fault current data under various saturation fault conditions.

[0078] S260: Determine a saturation fault detection result of the target current transformer according to the similarity calculation result.

[0079] The technical solution of the embodiment of the present application pre-generates fault current data under various fault conditions so that each fault current data covers all possible situations where fault saturation may occur. After performing a similarity test between the target current data and the fault current data, if there is no calculation result with a similarity greater than a similarity threshold, it means that the target current data and each fault current data are not similar, that is, they do not meet any situation where a saturation fault occurs, and it can be determined that the target current transformer does not have a saturation fault.

[0080] Embodiment 3

[0081] Figure 4This is a schematic diagram of the structure of a saturation fault identification device for a current transformer provided in the third embodiment of the present application. The device can execute the saturation fault identification method for a current transformer provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method. Figure 4 As shown, the device comprises:

[0082] The target current data acquisition module 310 is used to acquire the target current data detected by the target current transformer after the fault occurs if it is determined that the target line has a short circuit fault; the target current transformer is used to detect the current of the target line;

[0083] A similarity calculation module 320 is used to respectively calculate the similarity between the target current data and the fault current data under various saturation fault conditions; the fault occurrence time and / or fault occurrence location under different saturation fault conditions are different;

[0084] The saturation fault detection result determination module 330 is used to determine the saturation fault detection result of the target current transformer according to the similarity calculation result.

[0085] The technical solution of the embodiment of the present application includes: a target current data acquisition module 310, which is used to obtain the target current data detected by the target current transformer after the fault occurs if it is determined that a short circuit fault occurs in the target line; the target current transformer is used to detect the current of the target line; a similarity calculation module 320, which is used to respectively calculate the similarity between the target current data and the fault current data under various saturation fault conditions; the fault occurrence time and / or fault occurrence location under different saturation fault conditions are different; a saturation fault detection result determination module 330, which is used to determine the saturation fault detection result of the target current transformer according to the similarity calculation result. By calculating the similarity between the target current data after the short circuit and the fault current data, the technical solution can determine whether a saturation fault occurs in the target current transformer according to the similarity calculation result, thereby providing support for the safe operation of the distribution network.

[0086] In the embodiment of the present application, optionally, the device further includes: a fault current data determination module, including:

[0087] A fault current value determination unit, used to determine the fault current value of the secondary side of the current transformer at each time point within a power frequency cycle starting from the time when the fault occurs, according to the line information that can trigger the current transformer saturation fault;

[0088] The fault current data generating unit is used to determine the time series fault current data according to the fault current value at each time point.

[0089] In an embodiment of the present application, optionally, the fault current value determining unit includes:

[0090] The fault current value determination subunit is used to determine the fault current value of the secondary side of the current transformer according to the current transformer ratio, the three-phase fault steady-state current amplitude, the power frequency, the sampling frequency, the initial phase of the fault fundamental wave, the amplitude of the non-periodic component and the decay time constant.

[0091] In the embodiment of the present application, optionally, the fault current value determination subunit is specifically used to:

[0092] Determine the fault current value on the secondary side of the current transformer according to the following formula:

[0093]

[0094] Among them, I 2 (j) is the fault current value on the secondary side of the current transformer, K is the current transformer ratio, I M is the three-phase fault steady-state current amplitude, f n is the power frequency, t(j) is the jth time point, j is the number of the time point, f s is the sampling frequency, is the initial phase of the fault fundamental wave, k 0 is the amplitude of the non-periodic component, and τ is the decay time constant.

[0095] In the embodiment of the present application, optionally, the similarity calculation module 320 includes:

[0096] A normalization processing unit, used for normalizing the fault current data to obtain normalized fault current data;

[0097] The similarity calculation unit is used to determine the similarity between the target current data and the fault current data based on the following formula:

[0098]

[0099] Where cosk is the similarity between the target current data and the fault current data under the kth saturation fault condition, I n (j) is the target current data, I' 2k (j) is the fault current data under the kth saturation fault condition, is the number of current values ​​included in the current data, and j is the number of the current value.

[0100] In the embodiment of the present application, optionally, the device further includes: a fault occurrence time determination module, including:

[0101] A detection current data determination unit, used to obtain detection current data of a target current transformer in a target time period; the target time period includes the time when a short circuit fault of a target line occurs;

[0102] a target current value determination unit, configured to determine a target current value satisfying a current jump condition in the detected current data;

[0103] The fault occurrence time determination unit is used to determine the sampling time corresponding to the target current value as the fault occurrence time.

[0104] In an embodiment of the present application, optionally, the target current value determining unit includes:

[0105] A difference calculation subunit is used to traverse the detection current values ​​in the detection current data and calculate the difference between the current detection current value and the reference detection current value; the sampling time of the reference current value is one power frequency cycle before the sampling time of the current detection current value;

[0106] The target current value determination subunit is used to determine the current detection current value as the target current value if the absolute value of the difference calculation result is greater than a preset current threshold.

[0107] A saturation fault identification device for a current transformer provided in an embodiment of the present application can execute a saturation fault identification method for a current transformer provided in any embodiment of the present invention, and has functional modules and beneficial effects corresponding to the execution method.

[0108] Embodiment 4

[0109] Figure 5 A schematic diagram of the structure of an electronic device 10 that can be used to implement an embodiment of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0110] like Figure 5As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0111] A number of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0112] The processor 11 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as a saturation fault identification method for a current transformer.

[0113] In some embodiments, the saturation fault identification method of the current transformer can be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the saturation fault identification method of the current transformer described above can be performed. Alternatively, in other embodiments, the processor 11 can be configured to execute the saturation fault identification method of the current transformer in any other appropriate manner (for example, by means of firmware).

[0114] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0115] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0116] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0117] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0118] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0119] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0120] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0121] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for identifying saturation fault of a current transformer, characterized in that: include: If it is determined that a short circuit fault occurs in the target line, then obtaining target current data detected by the target current transformer after the fault occurs; The target current transformer is used to detect the current of the target line; respectively calculating the similarity between the target current data and the fault current data under various saturation fault conditions; The fault occurrence time and / or fault occurrence location are different under different saturation fault conditions; According to the similarity calculation result, the saturation fault detection result of the target current transformer is determined.

2. The method according to claim 1, characterized in that A process for determining fault current data under a saturation fault condition includes: Starting from the time when the fault occurs, the fault current value of the secondary side of the current transformer at each time point within a power frequency cycle is determined according to the line information that can trigger the current transformer saturation fault; The fault current data of the time series is determined according to the fault current value at each time point.

3. The method according to claim 2, characterized in that Determining a fault current value on the secondary side of the current transformer according to line information that can trigger a current transformer saturation fault includes: The fault current value on the secondary side of the current transformer is determined according to the current transformer ratio, the three-phase fault steady-state current amplitude, the power frequency, the sampling frequency, the initial phase of the fault fundamental wave, the amplitude of the non-periodic component and the decay time constant.

4. The method according to claim 3, characterized in that The fault current value on the secondary side of the current transformer is determined according to the current transformer ratio, the three-phase fault steady-state current amplitude, the power frequency, the sampling frequency, the initial phase of the fault fundamental wave, the amplitude of the non-periodic component and the decay time constant, including: Determine the fault current value on the secondary side of the current transformer according to the following formula: Where I2(j) is the fault current value on the secondary side of the current transformer, K is the current transformer ratio, I M is the three-phase fault steady-state current amplitude, f n is the power frequency, t(j) is the jth time point, j is the number of the time point, f s is the sampling frequency, is the initial phase of the fault fundamental wave, k0 is the amplitude of the non-periodic component, and τ is the decay time constant.

5. The method according to claim 1, characterized in that Calculate the similarity between the target current data and the fault current data, including: Normalizing the fault current data to obtain normalized fault current data; The similarity between the target current data and the fault current data is determined based on the following formula: Where cosk is the similarity between the target current data and the fault current data under the kth saturation fault condition, I n (j) is the target current data, I' 2k (j) is the fault current data under the kth saturation fault condition, is the number of current values ​​included in the current data, and j is the number of the current value.

6. The method according to claim 1, characterized in that The process of determining the fault occurrence time includes: Acquire detection current data of a target current transformer in a target time period; the target time period includes the time when a short circuit fault of a target line occurs; In the detected current data, determining a target current value that satisfies a current jump condition; The sampling time corresponding to the target current value is determined as the fault occurrence time.

7. The method according to claim 6, characterized in that In the detected current data, determining a target current value that satisfies a current jump condition comprises: Traversing the detection current values ​​in the detection current data, and calculating the difference between the current detection current value and the reference detection current value; the sampling time of the reference current value is one power frequency cycle before the sampling time of the current detection current value; If the absolute value of the difference calculation result is greater than the preset current threshold, the current detection current value is determined to be the target current value.

8. A saturation fault identification device for a current transformer, characterized in that: include: A target current data acquisition module is used to acquire target current data detected by the target current transformer after the fault occurs if it is determined that a short circuit fault occurs in the target line; The target current transformer is used to detect the current of the target line; A similarity calculation module, used to respectively calculate the similarity between the target current data and the fault current data under various saturation fault conditions; The fault occurrence time and / or fault occurrence location are different under different saturation fault conditions; The saturation fault detection result determination module is used to determine the saturation fault detection result of the target current transformer according to the similarity calculation result.

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the saturation fault identification method for a current transformer according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the saturation fault identification method of a current transformer according to any one of claims 1 to 7 when executed.

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