A method, device, equipment and medium for identifying disturbances in parallel capacitors in a substation

Abstract

The present invention discloses a method, device, equipment and medium for identifying disturbances in parallel capacitors in a substation, comprising: obtaining multiple monitoring signals within multiple cycles of at least one monitoring point on each busbar of the substation; processing each monitoring signal to obtain a processed monitoring signal; calculating the waveform shape similarity of the processed monitoring signals within adjacent cycles of each monitoring point to form a similarity curve; when the similarity curve is lower than a threshold curve, determining that a disturbance has occurred in the current cycle; obtaining the disturbance power within the current cycle, and the current at the monitoring point before and / or after the disturbance occurs; and determining the disturbance type based on the disturbance power and current. This identification method can obtain the disturbance type on the parallel capacitor by directly obtaining the monitoring signal of the monitoring point and performing simple calculations based on the monitoring signal. Furthermore, this method can simultaneously obtain the disturbance condition of the entire parallel capacitor group, with high efficiency and accurate identification.

Description

Technical Field

[0001] The present invention relates to the technical field of substations, and in particular to a method, device, equipment and medium for identifying disturbances of shunt capacitors in substations. Background Art

[0002] As key equipment for reactive power compensation and power quality management, the operating status of parallel capacitor banks is becoming increasingly important for the safe and efficient operation of the system as the scale of power systems expands and users' requirements for power quality increase. The disturbances caused by parallel capacitor banks can be mainly divided into two categories, namely capacitor switching disturbances and internal fault disturbances. Capacitor switching disturbances reflect the normal working state of the capacitor, while capacitor internal fault disturbances reflect potential fault hazards or abnormal conditions of the capacitor. Rapid identification of capacitor disturbance types is the basis for achieving capacitor status perception. Currently, waveform monitoring devices at key nodes of the distribution network are mainly used to monitor the three-phase voltage and current waveforms. Based on the typical characteristics of transient disturbances caused by capacitor switching and internal faults, appropriate feature extraction and identification methods are used to identify disturbances caused by capacitor switching or internal faults. This method has high identification accuracy, but the algorithm involves a large amount of computation, making it difficult to quickly identify disturbances in multiple capacitor banks. Summary of the Invention

[0003] The present invention provides a method, device, equipment and medium for identifying disturbances of parallel capacitors in a transformer substation, so as to realize rapid identification of disturbances of multiple capacitor groups.

[0004] To achieve the above objectives, a first embodiment of the present invention provides a method for identifying disturbances in parallel capacitors in a substation, comprising:

[0005] Acquire multiple monitoring signals within multiple cycles of at least one monitoring point on each busbar of the substation;

[0006] Processing each of the monitoring signals to obtain a processed monitoring signal;

[0007] Calculating waveform similarity of the processed monitoring signals within adjacent cycles of each monitoring point to form a similarity curve;

[0008] When the similarity curve is lower than the threshold curve, it is determined that the current cycle is disturbed.

[0009] Optionally, the method further comprises: acquiring the disturbance power in the current cycle, and the current at the monitoring point before and / or after the disturbance occurs;

[0010] A disturbance type is determined according to the disturbance power and the current.

[0011] Optionally, the processing each of the monitoring signals, obtaining and processing the monitoring signals includes:

[0012] The monitoring signal is normalized after taking its absolute value.

[0013] Optionally, the monitoring signal y i (i=1,2,...) satisfies the following relationship:

[0014] in is the normalized signal, E t Corresponding to y k (k∈i, i=1,2,...,N) is the signal energy within the cycle, N is the number of monitoring signals sampled within one cycle, and t is the sampling time of one cycle.

[0015] Optionally, performing waveform shape similarity calculation on the processed monitoring signals within adjacent cycles of each monitoring point to form a similarity curve includes:

[0016] Comparing the processed monitoring signals at corresponding sequential points in adjacent cycles to obtain multiple minimum values;

[0017] Summing the processed monitoring signals in adjacent cycles to obtain a first sum value;

[0018] Calculate twice the sum of the plurality of minimum values ​​to obtain a second sum;

[0019] using the ratio of the second sum value to the first sum value as the similarity between adjacent cycles;

[0020] The above steps are repeated in sequence to obtain similarities between a plurality of adjacent cycles to form a similarity curve.

[0021] Optionally, the similarity curve S c The following relationship is satisfied:

[0022] in, and is the representation of adjacent cycles, k∈i, i=1,2...,N r .

[0023] Optionally, the similarity curve S c The corresponding threshold curve ρ(S c ) satisfies the following relationship:

[0024] ρ(S c )=1-μ×median{1-S ref},ref=cw,...,c-1;

[0025] Where μ is a constant, S refis a sliding interval of length w.

[0026] Optionally, when the similarity curve is lower than a threshold curve, after determining that a disturbance occurs in the current cycle, the method further includes:

[0027] Update the threshold curve, ρ(S y )=ρ(S c* ),y=c * +1,...,c * +w, where c * Indicates the frequency number corresponding to the current frequency, ρ(S y ) represents the updated threshold curve.

[0028] Optionally, obtaining the disturbance power in the current cycle includes:

[0029] Obtaining the difference between the three-phase sampled voltages in the previous cycle and the current cycle;

[0030] Obtaining the difference between the three-phase sampled currents in the previous cycle and the current cycle;

[0031] Clarke transform is performed on the difference between the three-phase sampled voltages and the difference between the three-phase sampled currents to obtain disturbance power.

[0032] Optionally, the determining the disturbance type according to the disturbance power and the current includes:

[0033] If ΔP < 0, and the current at the monitoring point was zero before the disturbance occurred, the disturbance type corresponds to the downstream capacitor bank being put into operation;

[0034] If ΔP<0, and the current at the monitoring point suddenly changes to zero after the disturbance occurs, the disturbance type corresponds to the downstream capacitor bank being cut off;

[0035] If ΔP<0, and the current at the monitoring point is not zero before and after the disturbance occurs, then the disturbance type corresponds to an internal fault of the downstream capacitor bank;

[0036] If ΔP>0, the disturbance type is located at a device upstream of the monitoring point, where ΔP is the disturbance power.

[0037] To achieve the above-mentioned object, a second embodiment of the present invention provides a substation shunt capacitor disturbance identification device, which is used to implement the substation shunt capacitor disturbance identification method as described in any embodiment of the present invention, comprising:

[0038] A monitoring signal acquisition module, used to acquire multiple monitoring signals within multiple cycles of at least one monitoring point on each busbar of the substation;

[0039] A processing module, configured to process each of the monitoring signals to obtain a processed monitoring signal;

[0040] A similarity curve forming module is used to calculate the waveform shape similarity of the processed monitoring signals within adjacent cycles of each monitoring point to form a similarity curve;

[0041] The disturbance judgment module is used to judge whether the current cycle is disturbed when the similarity curve is lower than the threshold curve.

[0042] To achieve the above objectives, a third embodiment of the present invention provides an electronic device for identifying disturbances in parallel capacitors in a substation, the electronic device comprising:

[0043] at least one processor; and

[0044] a memory communicatively connected to the at least one processor; wherein,

[0045] 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 substation shunt capacitor disturbance identification method according to any embodiment of the present invention.

[0046] To achieve the above-mentioned purpose, the fourth aspect of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the substation parallel capacitor disturbance identification method described in any embodiment of the present invention when executed.

[0047] In summary, the method, device, equipment and medium for identifying disturbances in parallel capacitors in substations proposed in accordance with an embodiment of the present invention include: obtaining multiple monitoring signals within multiple cycles of at least one monitoring point on each busbar of the substation; processing each monitoring signal to obtain a processed monitoring signal; calculating the waveform shape similarity of the processed monitoring signals within adjacent cycles of each monitoring point to form a similarity curve; when the similarity curve is lower than the threshold curve, determining that a disturbance has occurred in the current cycle; obtaining the disturbance power within the current cycle, and the current at the monitoring point before and / or after the disturbance occurs; and determining the type of disturbance based on the disturbance power and current. This identification method can obtain the type of disturbance on the parallel capacitor by directly obtaining the monitoring signal of the monitoring point and performing simple calculations based on the monitoring signal, and this method can simultaneously obtain the disturbance condition of the entire parallel capacitor group, with high efficiency and accurate identification.

[0048] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. 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.

[0050] Figure 1 This is a flow chart of a method for identifying disturbances in parallel capacitors in a substation proposed in an embodiment of the present invention;

[0051] Figure 2 It is a schematic diagram of a substation busbar system in related technology;

[0052] Figure 3 This is a frequency sampling diagram in the substation parallel capacitor disturbance method proposed in an embodiment of the present invention;

[0053] Figure 4 is a flow chart of a method for identifying disturbances in parallel capacitors in a substation, according to another embodiment of the present invention;

[0054] Figure 5 1 is a block diagram of a substation shunt capacitor disturbance identification device according to an embodiment of the present invention;

[0055] Figure 6 is a block diagram of a substation shunt capacitor disturbance identification device proposed in another embodiment of the present invention;

[0056] Figure 7 Schematic diagram of a substation shunt capacitor disturbance identification electronic device proposed in an embodiment of the present invention. DETAILED DESCRIPTION

[0057] In order to enable those skilled in the art to better understand the solutions of the present invention, 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 embodiments described are only 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 efforts should fall within the scope of protection of the present invention.

[0058] It should be noted that the terms "first", "second", etc. in the description 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 numbers 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.

[0059] Figure 1 This is a flow chart of a method for identifying disturbances in parallel capacitors in substations proposed in an embodiment of the present invention.

[0060] like Figure 1 As shown, the identification method includes:

[0061] S101, obtaining multiple monitoring signals within multiple cycles of at least one monitoring point on each busbar of a substation.

[0062] The busbar system diagram of the substation in S101 is as follows: Figure 2 As shown, there are monitoring points on each bus. These monitoring points are set in the relevant technology to monitor bus parameters, and the signals of these monitoring points can be monitored by relevant monitoring instruments and then transmitted to the corresponding server. The monitoring signal in S101 can be three-phase current or three-phase voltage.

[0063] S102: Process each monitoring signal to obtain a processed monitoring signal.

[0064] Optionally, the monitoring signal is normalized after taking its absolute value.

[0065] Among them, the monitoring signal y i (i=1,2,...) satisfies the following relationship:

[0066] in is the normalized signal, E t Corresponding to y k (k∈i, i=1,2,...,N) is the signal energy within a cycle, N is the number of monitoring signals sampled within a cycle, and t is the sampling time of a cycle.

[0067] For example, Figure 2Taking monitoring point 1, monitoring point 2 and monitoring point 3 in the example, while obtaining the continuous cycle corresponding monitoring signals of monitoring point 1, monitoring point 2 and monitoring point 3 in step S101, the monitoring signal of each monitoring point is positive, and then the square of each positive monitoring signal in each cycle is summed. Finally, according to the formula Get the normalized value of one of the monitoring signals within a cycle For example, if monitoring point 2 has N monitoring signals in its first cycle, N monitoring signals in its second cycle, and so on, and multiple cycles are monitored, then the monitoring signals in each cycle need to be positively rectified and normalized to form a similarity curve in step S103. Monitoring points 1 and 3 can refer to the processing method of monitoring point 2.

[0068] S103 , performing waveform shape similarity calculation on the processed monitoring signals within adjacent cycles of each monitoring point to form a similarity curve.

[0069] Wherein, S103 includes comparing the processed monitoring signals at corresponding sequential points in adjacent cycles to obtain multiple minimum values;

[0070] Summing each processed monitoring signal in adjacent cycles to obtain a first sum value;

[0071] Calculate twice the sum of multiple minimum values ​​and obtain the second sum;

[0072] The ratio of the second sum value to the first sum value is taken as the similarity between adjacent cycles;

[0073] The above steps are repeated in sequence to obtain the similarities of multiple adjacent cycles to form a similarity curve.

[0074] Among them, the similarity curve Sc satisfies the following relationship:

[0075] in, and is the representation of adjacent cycles, k∈i, i=1,2...,N r .

[0076] For example, Figure 2For example, if N points were collected in the first cycle and N points were collected in the second cycle, then the monitoring signals of the first point in the first cycle and the first point in the second cycle were compared and the minimum value was selected. Next, the monitoring signals of the second point in the first cycle and the second point in the second cycle were compared and the minimum value was selected. This process was repeated until the minimum value of the last group was compared. Each minimum value was then added and multiplied by 2 as the numerator. The sum of the monitoring signals was used as the denominator to calculate the similarity between the first and second cycles. After collecting multiple cycles continuously, a similarity curve was formed.

[0077] S104, when the similarity curve is lower than the threshold curve, it is determined that the current frequency is disturbed. When the similarity curve is lower than the threshold curve, after determining that the current frequency is disturbed, the method further includes: updating the threshold curve.

[0078] Among them, the similarity curve S c The corresponding threshold curve ρ(S c ) satisfies the following relationship: ρ(S c )=1-μ×median{1-S ref},ref=cw,...,c-1; where μ is a constant, S re f is a sliding interval of length w.

[0079] That is, the similarity curve formed by the next w cycles within the c cycles can be solved in the same manner as in step S103, and finally the threshold curve can be obtained by the above formula, where the value of μ can be 1.2. For example, if c is 200 and w can be 10, then the similarity curve of the cycles between the 189th and 199th cycles can be calculated as the threshold curve. And when the similarity curve of the current cycle is less than the threshold curve, the threshold curve is updated. That is, when the inequality S is satisfied, c <ρ(S c ) is detected, and the threshold curve is according to the formula Update, where c * Indicates the cycle number in which the last disturbance was detected. For example, if a disturbance is detected at the 200th cycle, and w is 10, the similarity curve for cycles 201 to 210 can be used as the threshold curve. w can be 10, 11, or 12. w can also be preset based on actual conditions.

[0080] In another embodiment, Figure 4 As shown, the method further includes:

[0081] S105 , obtaining the disturbance power in the current cycle and the current at the monitoring point before and / or after the disturbance occurs.

[0082] Obtaining the disturbance power in the current cycle includes:

[0083] Get the difference between the three-phase sampled voltages in the previous cycle and the current cycle;

[0084] Obtain the difference between the three-phase sampling current in the previous cycle and the current cycle;

[0085] Clarke transform is performed on the difference between the three-phase sampled voltage and the three-phase sampled current to obtain the disturbance power.

[0086] The disturbance power is the integrated average value of the inner product of the disturbance voltage vector and the disturbance current vector within one cycle of the monitoring point, as shown in the relationship: In order to obtain the disturbance voltage and current vector, a phase-locked loop is required to synchronously sample the voltage and current in each cycle, such as Figure 3 As shown in Figure 2, the disturbance voltage and disturbance current of monitoring point 2 are obtained.

[0087] in, u p and u d Denote the sampled voltages before and during the disturbance, respectively, and the same is true for the sampled currents. N is the number of sampling points in one fundamental cycle, n = 1, 2, ..., N; k is an integer, which is the number of fundamental cycles between the sampling intervals of the voltage and current waveforms before and during the disturbance; x∈[a, b, c], where a, b, and c represent the three phases. Clark transform of the three-phase disturbance voltage and current yields:

[0088]

[0089]

[0090] in, ΔU and ΔI are 3×N matrices formed by sampling data of one cycle of three-phase abc. Then the disturbance power is: α and β are the coordinate axes of Clarke transformation.

[0091] S106, determining the disturbance type according to the disturbance power and current, wherein if ΔP>0, the disturbance source is located upstream of the monitoring point; if ΔP<0, the disturbance source is located downstream of the monitoring point.

[0092] Optionally, determining the disturbance type according to the disturbance power and current includes:

[0093] If ΔP < 0, and the current at the monitoring point was zero before the disturbance occurred, the disturbance type corresponds to the downstream capacitor bank being put into operation;

[0094] If ΔP < 0, and the current at the monitoring point suddenly changes to zero after the disturbance occurs, the disturbance type corresponds to the disconnection of the downstream capacitor bank;

[0095] If ΔP < 0, and the current at the monitoring point is not zero before and after the disturbance occurs, the disturbance type corresponds to an internal fault of the downstream capacitor bank;

[0096] If ΔP > 0, the disturbance type is located in the device upstream of the monitoring point, where ΔP is the disturbance power. The disturbance corresponds to a disturbance in other feeder capacitor banks or other parts of the system. The same method can be used to identify disturbances in the capacitor banks of each feeder.

[0097] Therefore, by calculating the three-phase current and three-phase voltage and projecting them onto the α and β components, the calculation is simpler and the collected signals are more comprehensive.

[0098] Figure 5 This is a block diagram of a substation shunt capacitor disturbance identification device proposed in an embodiment of the present invention, which is used to implement a substation shunt capacitor disturbance identification method as in any embodiment of the present invention, such as Figure 5 Shown, including:

[0099] The monitoring signal acquisition module 101 is used to acquire multiple monitoring signals within multiple cycles of at least one monitoring point on each busbar of the substation;

[0100] The processing module 102 is used to process each monitoring signal and obtain a processed monitoring signal;

[0101] The similarity curve forming module 103 is used to calculate the waveform shape similarity of the processed monitoring signals within adjacent cycles of each monitoring point to form a similarity curve;

[0102] The disturbance determination module 104 is configured to determine that a disturbance occurs in the current cycle when the similarity curve is lower than a threshold curve.

[0103] In another embodiment, Figure 6 As shown, the device further includes: a second acquisition module 105, configured to acquire the disturbance power in the current cycle, and the current at the monitoring point before and / or after the disturbance occurs;

[0104] The type determination module 106 is configured to determine the disturbance type according to the disturbance power and current.

[0105] Optionally, the processing module 102 is configured to take an absolute value of the monitoring signal and then perform normalization processing.

[0106] Optionally, monitoring signal y i (i=1,2,...) satisfies the following relationship:

[0107] in is the normalized signal, E t Corresponding to y k(k∈i, i=1,2,...,N) is the signal energy within a cycle, N is the number of monitoring signals sampled within a cycle, and t is the sampling time of a cycle.

[0108] Optionally, the similarity curve forming module 103 includes:

[0109] A comparison unit, used to compare the processed monitoring signals at corresponding sequential points in adjacent cycles to obtain multiple minimum values;

[0110] a first calculation unit, configured to sum each processed monitoring signal in adjacent cycles to obtain a first sum value;

[0111] a second calculating unit, configured to calculate twice the sum of the plurality of minimum values ​​to obtain a second sum;

[0112] a third calculating unit, configured to use a ratio of the second sum value to the first sum value as a similarity between adjacent cycles;

[0113] The forming unit is used to sequentially obtain similarities of multiple adjacent cycles to form a similarity curve.

[0114] Optionally, the similarity curve S c The following relationship is satisfied:

[0115] in, and is the representation of adjacent cycles, k∈i, i=1,2...,N r .

[0116] Optionally, the similarity curve S c The corresponding threshold curve ρ(S c ) satisfies the following relationship:

[0117] ρ(S c )=1-μ×median{1-S ref},ref=cw,...,c-1;

[0118] Where μ is a constant, S ref is a sliding interval of length w.

[0119] Optionally, it also includes: an update module.

[0120] Update threshold curve, ρ(S y )=ρ(S c* ),y=c * +1,...,c * +w, where c * Indicates the frequency number corresponding to the current frequency, ρ(S y ) represents the updated threshold curve.

[0121] Optionally, the second acquisition module 105 includes:

[0122] The first acquisition unit is used to obtain the difference between the three-phase sampled voltages in the previous cycle and the current cycle;

[0123] The second acquisition unit is used to obtain the difference between the three-phase sampling currents in the previous cycle and the current cycle;

[0124] The third acquisition unit is configured to perform Clarke transformation on the difference between the three-phase sampled voltages and the difference between the three-phase sampled currents to acquire the disturbance power.

[0125] Optionally, the type determination module 106 includes:

[0126] A first determining unit is configured to determine that the disturbance type corresponds to the downstream capacitor bank being switched on if ΔP < 0 and the current at the monitoring point has been zero before the disturbance occurs;

[0127] A second determining unit is configured to determine that if ΔP is less than 0 and the current at the monitoring point suddenly changes to zero after the disturbance occurs, the disturbance type corresponds to the disconnection of the downstream capacitor bank;

[0128] A third determining unit is configured to determine that the disturbance type corresponds to an internal fault of the downstream capacitor bank if ΔP < 0 and the currents at the monitoring point are not zero before and after the disturbance occurs;

[0129] The fourth determining unit is configured to determine, if ΔP>0, that the disturbance type is a device located upstream of the monitoring point, wherein ΔP is the disturbance power.

[0130] The substation parallel capacitor disturbance identification device provided in the embodiment of the present invention can execute the substation parallel capacitor disturbance identification method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method, which will not be repeated in this embodiment.

[0131] Figure 7 FIG. 1 is a schematic diagram of an electronic device for identifying disturbances in parallel capacitors in a substation according to an embodiment of the present invention. Figure 7 As shown, the electronic device 10 includes:

[0132] at least one processor; and

[0133] a memory communicatively connected to at least one processor; wherein,

[0134] The memory stores a computer program that can be executed by at least one processor. The computer program is executed by the at least one processor so that the at least one processor can execute the substation parallel capacitor disturbance identification method according to any embodiment of the present invention.

[0135] An embodiment of the present invention further provides a computer-readable storage medium storing computer instructions, which are used to enable a processor to implement the substation parallel capacitor disturbance identification method of any embodiment of the present invention when executed.

[0136] Figure 7 A schematic diagram of the structure of an electronic device 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.

[0137] like Figure 7 As 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 the 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. Various programs and data required for the operation of the electronic device 10 can also be stored in the RAM 13. The processor 11, ROM 12 and RAM 13 are connected to each other via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0138] Multiple 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 magnetic 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 via a computer network such as the Internet and / or various telecommunication networks.

[0139] The processor 11 can be any general-purpose and / or specialized processing component 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 specialized artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any other suitable processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as the method for identifying disturbances in substation shunt capacitors.

[0140] In some embodiments, the substation shunt capacitor disturbance identification method may be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as the storage unit 18. In some embodiments, part or all of the computer program may 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 substation shunt capacitor disturbance identification method described above may be performed. Alternatively, in other embodiments, the processor 11 may be configured to execute the substation shunt capacitor disturbance identification method in any other appropriate manner (e.g., by means of firmware).

[0141] Various embodiments of the systems and techniques described 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), system-on-chip systems (SOCs), programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include being implemented in one or more computer programs that are executable and / or interpreted on a programmable system that includes 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.

[0142] 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, such that when the computer program is executed by the processor, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The computer program may be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0143] In the context of the present invention, computer-readable storage media can be tangible media that can contain or store a computer program for use with an instruction execution system, device or equipment or used in combination with an instruction execution system, device or equipment. Computer-readable storage media can include but are not limited to electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, computer-readable storage media can be machine-readable signal media. More specific examples of machine-readable storage media can include electrical connections based on one or more lines, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0144] To provide interaction with a user, the systems and techniques described herein can 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 pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0145] The systems and techniques described herein can be implemented in a computing system that includes back-end 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 front-end components (e.g., a user computer with a graphical user interface or 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 back-end components, middleware components, or front-end components. The components of the system can 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.

[0146] A computing system may include clients and servers. The clients and servers are typically remote from each other and typically interact via a communication network. This client-server relationship arises through computer programs running on the respective computers, creating a client-server relationship. The server may be a cloud server, also known as a cloud computing server or cloud host. This server is a hosting product within the cloud computing service ecosystem that addresses the management difficulties and limited scalability of traditional physical hosting and VPS services.

[0147] In summary, the method, device, equipment and medium for identifying disturbances in parallel capacitors in substations proposed in accordance with an embodiment of the present invention include: obtaining multiple monitoring signals within multiple cycles of at least one monitoring point on each busbar of the substation; processing each monitoring signal to obtain a processed monitoring signal; calculating the waveform shape similarity of the processed monitoring signals within adjacent cycles of each monitoring point to form a similarity curve; when the similarity curve is lower than the threshold curve, determining that a disturbance has occurred in the current cycle; obtaining the disturbance power within the current cycle, and the current at the monitoring point before and / or after the disturbance occurs; and determining the type of disturbance based on the disturbance power and current. This identification method can obtain the type of disturbance on the parallel capacitor by directly obtaining the monitoring signal of the monitoring point and performing simple calculations based on the monitoring signal, and this method can simultaneously obtain the disturbance condition of the entire parallel capacitor group, with high efficiency and accurate identification.

[0148] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.

[0149] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A method for identifying substation disturbances, characterized in that: include: Acquire multiple monitoring signals within multiple cycles of at least one monitoring point on each busbar of the substation; Processing each of the monitoring signals to obtain a processed monitoring signal; Calculating waveform similarity of the processed monitoring signals within adjacent cycles of each monitoring point to form a similarity curve; When the similarity curve is lower than the threshold curve, it is determined that the current cycle is disturbed; After determining that the current frequency is disturbed, the following steps are also included: Obtaining the disturbance power in the current cycle, and the current at the monitoring point before and / or after the disturbance occurs; determining a disturbance type according to the disturbance power and the current; The determining the disturbance type according to the disturbance power and the current includes: If ΔP < 0, and the current at the monitoring point was zero before the disturbance occurred, the disturbance type corresponds to the downstream capacitor bank being put into operation; If ΔP<0, and the current at the monitoring point suddenly changes to zero after the disturbance occurs, the disturbance type corresponds to the downstream capacitor bank being cut off; If ΔP<0, and the current at the monitoring point is not zero before and after the disturbance occurs, then the disturbance type corresponds to an internal fault of the downstream capacitor bank; If ΔP>0, the disturbance type is located at a device upstream of the monitoring point, where ΔP is the disturbance power.

2. The substation disturbance identification method according to claim 1, characterized in that: Processing each of the monitoring signals to obtain the processed monitoring signals includes: The monitoring signal is normalized after taking its absolute value.

3. The substation disturbance identification method according to claim 2, characterized in that: The monitoring signal y i (i=1,2,...) satisfies the following relationship: in is the normalized signal, E t Corresponding to y k (k∈i, i=1,2,...,N) is the signal energy in the cycle where N is the number of monitoring signals sampled in one cycle, and t is the sampling time of one cycle.

4. The substation disturbance identification method according to claim 1, characterized in that: Calculating waveform shape similarity of the processed monitoring signals within adjacent cycles of each monitoring point to form a similarity curve includes: Comparing the processed monitoring signals at corresponding sequential points in adjacent cycles to obtain multiple minimum values; Summing the processed monitoring signals in adjacent cycles to obtain a first sum value; Calculate twice the sum of the plurality of minimum values ​​to obtain a second sum; using the ratio of the second sum value to the first sum value as the similarity between adjacent cycles; The above steps are repeated in sequence to obtain similarities between a plurality of adjacent cycles to form a similarity curve.

5. The substation disturbance identification method according to claim 4, characterized in that: The similarity curve S c The following relationship is satisfied: in, and is the representation of adjacent cycles, k∈i, i=1,2...,N r .

6. The substation disturbance identification method according to claim 5, characterized in that: The similarity curve S c The corresponding threshold curve ρ(S c ) satisfies the following relationship: ρ(S c )=1-μ×median{1-S ref },ref=c-w,...,c-1; Where μ is a constant, S ref is a sliding interval of length w.

7. The substation disturbance identification method according to claim 6, characterized in that: When the similarity curve is lower than the threshold curve, after determining that the current cycle is disturbed, the method further includes: Update the threshold curve, ρ(S y )=ρ(S c *),y=c * +1,...,c * +w, where c * Indicates the frequency number corresponding to the current frequency, ρ(S y ) represents the updated threshold curve.

8. The substation disturbance identification method according to claim 1, characterized in that: The obtaining of the disturbance power in the current cycle includes: Obtaining the difference between the three-phase sampled voltages in the previous cycle and the current cycle; Obtaining the difference between the three-phase sampled currents in the previous cycle and the current cycle; Clarke transform is performed on the difference between the three-phase sampled voltages and the difference between the three-phase sampled currents to obtain disturbance power.

9. A substation disturbance identification device, characterized in that: A method for identifying a substation disturbance according to any one of claims 1 to 8, comprising: A monitoring signal acquisition module, used to acquire multiple monitoring signals within multiple cycles of at least one monitoring point on each busbar of the substation; A processing module, configured to process each of the monitoring signals to obtain a processed monitoring signal; A similarity curve forming module is used to calculate the waveform shape similarity of the processed monitoring signals within adjacent cycles of each monitoring point to form a similarity curve; The disturbance judgment module is used to judge whether the current cycle is disturbed when the similarity curve is lower than the threshold curve.

10. An electronic device for identifying disturbances in a substation, 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. The computer program is executed by the at least one processor so that the at least one processor can perform the substation disturbance identification method according to any one of claims 1 to 8.

11. 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 substation disturbance identification method according to any one of claims 1 to 8 when executed.

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