Sympathetic inrush current identification method and device

Abstract

The invention provides a sympathetic inrush current identification method and device. The sympathetic inrush current identification method comprises the following steps: determining excitation current according to high-voltage side phase current and low-voltage side phase current; determining excitation inductance according to the excitation current, the sampling period and the phase current; fourier decomposition is carried out on the excitation inductor to obtain fundamental frequency data and triple frequency data of the excitation inductor; and identifying sympathetic inrush current according to the fundamental frequency data of the excitation inductor and the frequency tripling data to obtain a sympathetic inrush current identification result. The method is rapid and accurate in identification, simple in discrimination condition and convenient to implement.

Description

Technical Field

[0001] The present invention relates to the field of power system control and protection, and in particular to a method and device for identifying a response inrush current. Background Art

[0002] As one of the important equipment in the power system, the transformer is responsible for the transmission and conversion of electric energy on the one hand, and also plays a key role in the smooth operation of the power system on the other hand. The excitation surge current generated when the transformer is closed at no-load will flow through the system resistance to produce a DC voltage drop, causing asymmetric fluctuations in the bus voltage, which in turn causes the magnetic flux of the adjacent operating transformer on the bus to enter saturation and generate harmonic surge current. The generation of harmonic surge current will not only cause the transformer protection to malfunction, but also contain a large amount of harmonics and DC components that may affect the stability of the power grid and the normal operation of the converter. Therefore, the identification and anti-disturbance control of harmonic surge current is an important direction of transformer research.

[0003] Among the currently published patents, journals and conference documents, the research on the mechanism of transformer and inrush current is relatively sufficient, but the research on inrush current identification is relatively rare. The existing inrush current identification methods include four categories: the first is the identification method from current data, including intermittent angle braking, second harmonic braking, symmetrical waveform principle, etc.; the second is the method from the combination of current and voltage; the third is to use mathematical methods of signal processing for identification, and use signal processing tools to analyze the collected signal data in the time domain and frequency domain; the fourth is to use intelligent algorithms for supervised learning identification, combining the original protection strategy with the machine learning algorithm. However, the above methods have low recognition accuracy, high complexity and slow recognition speed. Summary of the invention

[0004] The main purpose of the embodiments of the present invention is to provide a method and device for identifying a response flow, which has rapid and accurate identification, simple judgment conditions, and is easy to implement.

[0005] In order to achieve the above object, an embodiment of the present invention provides a method for identifying a surge flow, including:

[0006] Determine the excitation current according to the high-voltage side phase current and the low-voltage side phase current;

[0007] Determine the excitation inductance according to the excitation current, the sampling period and the phase current;

[0008] Performing Fourier decomposition on the excitation inductance to obtain fundamental frequency data and triple frequency data of the excitation inductance;

[0009] The inrush current is identified according to the fundamental frequency data of the excitation inductance and the triple frequency data to obtain an inrush current identification result.

[0010] In one embodiment, it also includes:

[0011] The phase current is determined according to the high-voltage side phase current and the low-voltage side phase current.

[0012] In one embodiment, it also includes:

[0013] Determining the low-voltage side phase current according to the low-voltage side line current and the winding turns ratio;

[0014] When the high voltage side of the three-phase transformer is in angle connection, the high voltage side phase current is determined according to the high voltage side line current and the circulating current in the high voltage side angle winding.

[0015] In one embodiment, it also includes:

[0016] Determining the low-voltage side phase voltage according to the low-voltage side line voltage and the winding turns ratio;

[0017] When the high voltage side of the three-phase transformer is in delta connection, the high voltage side phase voltage is determined according to the high voltage side line voltage.

[0018] The embodiment of the present invention further provides a response flow identification device, comprising:

[0019] An excitation current determination module, used to determine the excitation current according to the high-voltage side phase current and the low-voltage side phase current;

[0020] An excitation inductance determination module, used to determine the excitation inductance according to the excitation current, sampling period and phase current;

[0021] A frequency data module, used for performing Fourier decomposition on the excitation inductance to obtain fundamental frequency data and triple frequency data of the excitation inductance;

[0022] The combined inrush current identification module is used to identify the combined inrush current according to the fundamental frequency data of the excitation inductance and the triple frequency data to obtain the combined inrush current identification result.

[0023] In one embodiment, it further includes: a phase current determination module, which is used to determine the phase current according to the high-voltage side phase current and the low-voltage side phase current.

[0024] In one embodiment, the low-voltage side phase current determination module is used to determine the low-voltage side phase current according to the low-voltage side line current and the winding turns ratio;

[0025] The high-voltage side phase current determination module is used to determine the high-voltage side phase current according to the high-voltage side line current and the circulating current in the high-voltage side angle winding when the high-voltage side of the three-phase transformer is in angle connection.

[0026] In one embodiment, it also includes:

[0027] A low-voltage side phase voltage determination module, used to determine the low-voltage side phase voltage according to the low-voltage side line voltage and the winding turns ratio;

[0028] The high-voltage side phase voltage determination module is used to determine the high-voltage side phase voltage according to the high-voltage side line voltage when the high-voltage side of the three-phase transformer is in a delta connection.

[0029] An embodiment of the present invention further provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor implements the steps of the method for identifying the inrush current when executing the computer program.

[0030] The embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for identifying the combined inrush current are implemented.

[0031] The embodiment of the present invention further provides a computer program product, including a computer program / instruction, which implements the steps of the response flow identification method when the computer program / instruction is executed by a processor.

[0032] The method and device for identifying the inrush current in the embodiment of the present invention first determine the excitation current based on the high-voltage side phase current and the low-voltage side phase current to further determine the excitation inductance based on the excitation current, the sampling period and the phase current, and then perform Fourier decomposition on the excitation inductance to obtain the fundamental frequency data and triple frequency data of the excitation inductance, thereby identifying the inrush current and obtaining the inrush current identification result. The identification is rapid and accurate, the judgment conditions are simple, and the implementation is convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, 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 paying creative work.

[0034] Figure 1 is a flow chart of a method for identifying a surge flow in an embodiment of the present invention;

[0035] Figure 2 is a flow chart of a method for identifying a surge flow in another embodiment of the present invention;

[0036] Figure 3 It is a measurement diagram of the star-delta connection method of a three-phase transformer in an embodiment of the present invention;

[0037] Figure 4 It is a measurement diagram of a three-phase transformer star-star connection method in an embodiment of the present invention;

[0038] Figure 5 It is a measurement diagram of a delta-delta connection method of a three-phase transformer in an embodiment of the present invention;

[0039] Figure 6 It is a measurement diagram of a delta-star connection method of a three-phase transformer in an embodiment of the present invention;

[0040] Figure 7 1 is a fast Fourier analysis schematic diagram of a fundamental frequency cycle of the instantaneous excitation inductance before the inrush current occurs in an embodiment of the present invention;

[0041] Figure 8 It is a fast Fourier analysis schematic diagram of a fundamental frequency cycle of the instantaneous excitation inductance after the inrush current occurs in the embodiment of the present invention;

[0042] Fig. 9 is a structural block diagram of a surge flow identification device in an embodiment of the present invention;

[0043] Fig.10 A schematic block diagram of the system structure of the electronic device 9600 according to an embodiment of the present application. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments 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 creative work are within the scope of protection of the present invention.

[0045] Those skilled in the art will appreciate that the embodiments of the present invention may be implemented as a system, device, apparatus, method or computer program product. Therefore, the present disclosure may be specifically implemented in the following forms, namely: complete hardware, complete software (including firmware, resident software, microcode, etc.), or a combination of hardware and software.

[0046] Figure 1 It is a flow chart of the method for identifying the response flow in an embodiment of the present invention. Figure 2 FIG. 1 is a flow chart of a method for identifying a surge flow in another embodiment of the present invention. Figure 1-Figure 2 As shown, the method for identifying the inrush current includes:

[0047] S101: Determine the excitation current according to the high-voltage side phase current and the low-voltage side phase current.

[0048] In specific implementation, the present invention collects the voltage and current on the high-voltage side and the low-voltage side of the transformer, and converts the voltage and current on one side to the voltage and current on the other side, specifically including:

[0049] Determining the low-voltage side phase current according to the low-voltage side line current and the winding turns ratio;

[0050] When the high voltage side of the three-phase transformer is in angle connection, the high voltage side phase current is determined according to the high voltage side line current and the circulating current in the high voltage side angle winding.

[0051] In one embodiment, before executing S101, the method further includes:

[0052] Determining the low-voltage side phase voltage according to the low-voltage side line voltage and the winding turns ratio;

[0053] When the high voltage side of the three-phase transformer is in delta connection, the high voltage side phase voltage is determined according to the high voltage side line voltage.

[0054] Figure 3 This is a measurement diagram of the three-phase transformer star-delta connection method in the embodiment of the present invention. The electrical quantities required to be collected on the high-voltage side and the low-voltage side are as follows: Figure 3 As shown in the annotation, the high-voltage side phase voltage and the converted low-voltage side phase voltage and phase current are calculated as follows:

[0055]

[0056]

[0057] Among them, u 1a 、u 1b 、u 1c Both are high-voltage side phase voltage, u 1ab 、u 1bc 、u 1ca are all high-voltage side line voltages, N is the ratio of the number of winding turns on the high-voltage side to the number of winding turns on the low-voltage side, are the converted low voltage side phase voltages, u 2ab 、u 2ab 、u 2ab All are low voltage side line voltage, i 2a 、i 2b 、i 2c All are low voltage side line current, are the converted low-voltage side phase currents, i 2cir is the internal circulating current of the low voltage side angle winding, i 2wab is the measured current of one-phase winding on the low-voltage side.

[0058] Figure 4 : is a measurement diagram of the three-phase transformer star-star connection method in the embodiment of the present invention. The electrical quantities to be collected on the high-voltage side and the low-voltage side are as follows: Figure 4 As shown in the mark, the high-voltage side phase voltage and the converted low-voltage side phase voltage and phase current are obtained by calculation:

[0059]

[0060]

[0061] Among them, u 1a 、u 1b 、u 1c Both are high-voltage side phase voltage, u 1ab 、u 1bc 、u 1ca are all high-voltage side line voltages, N is the ratio of the number of winding turns on the high-voltage side to the number of winding turns on the low-voltage side, are the converted low voltage side phase voltages, u 2ab 、u 2ab 、u 2ab All are low voltage side line voltage, i 2a 、i 2b 、i 2c All are low voltage side line current, Both are converted low-voltage side phase currents.

[0062] Figure 5 : is a measurement diagram of the delta-delta connection method of the three-phase transformer in the embodiment of the present invention. The electrical quantities to be collected on the high-voltage side and the low-voltage side are as follows: Figure 5 As shown in the mark, the high-voltage side phase current and the converted low-voltage side phase voltage and phase current are calculated as follows:

[0063]

[0064]

[0065] Among them, i 1a 、i 1b 、i 1c All are high-voltage side line current, i 1ab 、i 1bc 、i 1ca Both are high-voltage side phase currents, i 1cir is the internal circulating current of the high voltage side angle winding, i 1wab is the measured current of one phase winding on the high voltage side, N is the ratio of the number of turns of the winding on the high voltage side to that on the low voltage side, are the converted low voltage side phase voltages, u 2ab 、u 2ab 、u 2ab All are low voltage side line voltage, i 2a 、i 2b 、i 2c All are low voltage side line current, are the converted low-voltage side phase currents, i 2cir is the internal circulating current of the low voltage side angle winding, i 2wab is the measured current of one-phase winding on the low-voltage side.

[0066] Figure 6: is a measurement diagram of the delta-star connection method of the three-phase transformer in the embodiment of the present invention. The electrical quantities to be collected on the high-voltage side and the low-voltage side are as follows: Figure 6 As shown in the mark, the high-voltage side phase current and the converted low-voltage side phase voltage and phase current are calculated as follows:

[0067]

[0068] Among them, i 1a 、i 1b 、i 1c All are high-voltage side line current, i 1ab 、i 1bc 、i 1ca Both are high-voltage side phase currents, i 1cir is the internal circulating current of the high voltage side angle winding, i 1wab is the measured current of one phase winding on the high voltage side, N is the ratio of the number of turns of the winding on the high voltage side to that on the low voltage side, are the converted low voltage side phase voltages, u 2ab 、u 2ab 、u 2ab All are low voltage side line voltage, i 2a 、i 2b 、i 2c All are low voltage side line current, Both are converted low-voltage side phase currents.

[0069] Among them, Figure 3 and Figure 4 In the case of high voltage side line current equal to high voltage side phase current. Figure 5 and Figure 6 In the circuit, the line voltage on the high-voltage side is equal to the phase voltage on the high-voltage side.

[0070] S102: Determine the excitation inductance according to the excitation current, sampling period and phase current.

[0071] In one embodiment, before executing S102, the method further includes: determining the phase current according to the high-voltage side phase current and the low-voltage side phase current, as follows:

[0072]

[0073] Among them, i f is the phase current (transformer excitation current), i1 is the high-voltage side phase current measured or calculated above, and the positive direction is when it flows out of the transformer; It is the phase current converted from the low voltage side measured or calculated as above, and the current flowing out of the transformer is in the positive direction.

[0074] In one embodiment, the excitation inductance is calculated as follows:

[0075]

[0076] Among them, L m(k) is the k-th beat magnetizing inductance, i f(k) is the kth beat excitation current, u 1(k) is the high-voltage side phase voltage measured or calculated above at the kth beat, is the converted value of the low-voltage side phase voltage obtained by the above measurement or calculation at the kth beat, T c is the sampling period.

[0077] S103: Perform Fourier decomposition on the excitation inductance to obtain fundamental frequency data and triple frequency data of the excitation inductance.

[0078] In the specific implementation, the excitation inductance is normalized, and the normalized excitation inductance is subjected to fast Fourier decomposition in one fundamental frequency cycle to obtain its fundamental frequency amplitude L m(k)_1 and triple frequency amplitude L m(k)_3 .

[0079] S104: Identify the inrush current according to the fundamental frequency data of the excitation inductance and the triple frequency data, and obtain the inrush current identification result.

[0080] Figure 7 It is a fast Fourier analysis schematic diagram of a fundamental frequency cycle of the instantaneous excitation inductance before the inrush current occurs in an embodiment of the present invention. Figure 8 FIG. 1 is a schematic diagram of a fast Fourier analysis of a fundamental frequency cycle of the instantaneous excitation inductance after the inrush current occurs in the embodiment of the present invention. Figure 7-Figure 8 As shown in the figure, the amplitudes of the base frequency and triple frequency of the instantaneous excitation inductance before the inrush current occurs are 2.08 and 0.24 respectively, and the amplitudes of the base frequency and triple frequency of the instantaneous excitation inductance after the inrush current occurs are 35.92 and 18.04 respectively. Therefore, the threshold a can be set to 3 and b can be set to 1. At this time, the inrush current identification criterion W is as follows:

[0081] W:L m(k)_1 >3 and L m(k)_3 >1;

[0082] Among them, a and b are judgment thresholds, which are usually set according to the actual equipment. Generally, a is 3 to 8, and b is 1 to 10. When the judgment criterion W of any phase is true, the result of the sum inrush current identification is that the sum inrush current occurs; when the judgment criterion W of the three phases is false, the result of the sum inrush current identification is that the sum inrush current does not occur.

[0083] In summary, the present invention can identify the response surge after one cycle of its occurrence, and the identification is rapid and accurate. Meanwhile, the identification conditions are simple and easy to implement.

[0084] Based on the same inventive concept, an embodiment of the present invention also provides a response flow identification device. Since the principle of solving the problem by the device is similar to that of the response flow identification method, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be repeated.

[0085] Fig. 9 1 is a structural block diagram of a surge flow identification device in an embodiment of the present invention. Fig. 9 As shown, the surge flow identification device includes:

[0086] An excitation current determination module, used to determine the excitation current according to the high-voltage side phase current and the low-voltage side phase current;

[0087] An excitation inductance determination module, used to determine the excitation inductance according to the excitation current, sampling period and phase current;

[0088] A frequency data module, used for performing Fourier decomposition on the excitation inductance to obtain fundamental frequency data and triple frequency data of the excitation inductance;

[0089] The combined inrush current identification module is used to identify the combined inrush current according to the fundamental frequency data of the excitation inductance and the triple frequency data to obtain the combined inrush current identification result.

[0090] In one embodiment, it further includes: a phase current determination module, which is used to determine the phase current according to the high-voltage side phase current and the low-voltage side phase current.

[0091] In one embodiment, the low-voltage side phase current determination module is used to determine the low-voltage side phase current according to the low-voltage side line current and the winding turns ratio;

[0092] The high-voltage side phase current determination module is used to determine the high-voltage side phase current according to the high-voltage side line current and the circulating current in the high-voltage side angle winding when the high-voltage side of the three-phase transformer is in angle connection.

[0093] In one embodiment, it also includes:

[0094] A low-voltage side phase voltage determination module, used to determine the low-voltage side phase voltage according to the low-voltage side line voltage and the winding turns ratio;

[0095] The high-voltage side phase voltage determination module is used to determine the high-voltage side phase voltage according to the high-voltage side line voltage when the high-voltage side of the three-phase transformer is in a delta connection.

[0096] The combined inrush current identification device of the embodiment of the present invention first determines the excitation current according to the high-voltage side phase current and the low-voltage side phase current to further determine the excitation inductance according to the excitation current, the sampling period and the phase current, and then performs Fourier decomposition on the excitation inductance to obtain the fundamental frequency data and the triple frequency data of the excitation inductance, thereby identifying the combined inrush current and obtaining the combined inrush current identification result. The identification is rapid and accurate, the judgment conditions are simple, and the implementation is convenient.

[0097] Fig.10 FIG. 9 is a schematic block diagram of the system structure of the electronic device 9600 according to an embodiment of the present application. Fig.10 As shown, the electronic device 9600 may include a central processor 9100 and a memory 9140; the memory 9140 is coupled to the central processor 9100. It is worth noting that Fig.10 is exemplary; other types of structures may also be used to supplement or replace this structure to implement telecommunication functions or other functions.

[0098] In one embodiment, the function of the response flow identification method can be integrated into the central processing unit 9100. The central processing unit 9100 can be configured to perform the following control:

[0099] Determine the excitation current according to the high-voltage side phase current and the low-voltage side phase current;

[0100] Determine the excitation inductance according to the excitation current, the sampling period and the phase current;

[0101] Performing Fourier decomposition on the excitation inductance to obtain fundamental frequency data and triple frequency data of the excitation inductance;

[0102] The inrush current is identified according to the fundamental frequency data of the excitation inductance and the triple frequency data to obtain an inrush current identification result.

[0103] From the above description, it can be seen that the method for identifying the inrush current provided in the present application first determines the excitation current based on the high-voltage side phase current and the low-voltage side phase current to further determine the excitation inductance based on the excitation current, the sampling period and the phase current, and then performs Fourier decomposition on the excitation inductance to obtain the fundamental frequency data and triple frequency data of the excitation inductance, thereby identifying the inrush current and obtaining the inrush current identification result. The identification is rapid and accurate, the judgment conditions are simple, and it is easy to implement.

[0104] In another embodiment, the response flow identification device can be configured separately from the central processing unit 9100. For example, the response flow identification device can be configured as a chip connected to the central processing unit 9100, and the function of the response flow identification method can be implemented through the control of the central processing unit.

[0105] like Fig.10As shown, the electronic device 9600 may also include: a communication module 9110, an input unit 9120, an audio processor 9130, a display 9160, and a power supply 9170. It is worth noting that the electronic device 9600 does not necessarily have to include Fig.10 In addition, the electronic device 9600 may also include Fig.10 For components not shown, reference may be made to the prior art.

[0106] like Fig.10 As shown, the central processing unit 9100 is sometimes also referred to as a controller or an operation control, and may include a microprocessor or other processor device and / or logic device. The central processing unit 9100 receives input and controls the operation of various components of the electronic device 9600.

[0107] The memory 9140 may be, for example, one or more of a cache, a flash memory, a hard drive, a removable medium, a volatile memory, a non-volatile memory or other suitable devices. The above-mentioned information related to the failure may be stored, and a program for executing the relevant information may also be stored. The CPU 9100 may execute the program stored in the memory 9140 to implement information storage or processing, etc.

[0108] The input unit 9120 provides input to the central processing unit 9100. The input unit 9120 is, for example, a key or a touch input device. The power supply 9170 is used to provide power to the electronic device 9600. The display 9160 is used to display display objects such as images and texts. The display may be, for example, an LCD display, but is not limited thereto.

[0109] The memory 9140 may be a solid-state memory, such as a read-only memory (ROM), a random access memory (RAM), a SIM card, etc. It may also be a memory that saves information even when the power is off, can be selectively erased, and is provided with more data, examples of which are sometimes referred to as EPROMs, etc. The memory 9140 may also be some other type of device. The memory 9140 includes a buffer memory 9141 (sometimes referred to as a buffer). The memory 9140 may include an application / function storage unit 9142, which is used to store application programs and function programs or processes for executing the operation of the electronic device 9600 through the central processor 9100.

[0110] The memory 9140 may also include a data storage unit 9143 for storing data, such as contacts, digital data, pictures, sounds, and / or any other data used by the electronic device. The driver storage unit 9144 of the memory 9140 may include various drivers for communication functions of the electronic device and / or for executing other functions of the electronic device (such as messaging applications, address book applications, etc.).

[0111] The communication module 9110 is a transmitter / receiver 9110 that sends and receives signals via an antenna 9111. The communication module (transmitter / receiver) 9110 is coupled to the central processor 9100 to provide input signals and receive output signals, which may be the same as the case of a conventional mobile communication terminal.

[0112] Based on different communication technologies, multiple communication modules 9110 may be provided in the same electronic device, such as a cellular network module, a Bluetooth module and / or a wireless LAN module, etc. The communication module (transmitter / receiver) 9110 is also coupled to a speaker 9131 and a microphone 9132 via an audio processor 9130 to provide an audio output via the speaker 9131 and receive an audio input from the microphone 9132, thereby realizing a common telecommunication function. The audio processor 9130 may include any suitable buffer, decoder, amplifier, etc. In addition, the audio processor 9130 is also coupled to the central processor 9100, so that recording can be performed on the local machine through the microphone 9132, and the sound stored on the local machine can be played through the speaker 9131.

[0113] The embodiment of the present invention also provides a computer-readable storage medium capable of implementing all the steps of the method for identifying a combined flow in the above embodiment, where the execution subject is a server or a client. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, all the steps of the method for identifying a combined flow in the above embodiment are implemented. For example, when the processor executes the computer program, the following steps are implemented:

[0114] Determine the excitation current according to the high-voltage side phase current and the low-voltage side phase current;

[0115] Determine the excitation inductance according to the excitation current, the sampling period and the phase current;

[0116] Performing Fourier decomposition on the excitation inductance to obtain fundamental frequency data and triple frequency data of the excitation inductance;

[0117] The inrush current is identified according to the fundamental frequency data of the excitation inductance and the triple frequency data to obtain an inrush current identification result.

[0118] In summary, the computer-readable storage medium of the embodiment of the present invention first determines the excitation current according to the high-voltage side phase current and the low-voltage side phase current to further determine the excitation inductance according to the excitation current, the sampling period and the phase current, and then performs Fourier decomposition on the excitation inductance to obtain the fundamental frequency data and triple frequency data of the excitation inductance, thereby identifying the inrush current and obtaining the inrush current identification result, which has rapid and accurate identification, simple judgment conditions and is easy to implement.

[0119] The embodiment of the present invention also provides a computer program product capable of implementing all the steps of the method for identifying a combined flow in the above embodiment, where the execution subject is a server or a client. The computer program product includes a computer program / instruction. When the computer program / instruction is executed by a processor, all the steps of the method for identifying a combined flow in the above embodiment are implemented. For example, when the processor executes the computer program, the following steps are implemented:

[0120] Determine the excitation current according to the high-voltage side phase current and the low-voltage side phase current;

[0121] Determine the excitation inductance according to the excitation current, the sampling period and the phase current;

[0122] Performing Fourier decomposition on the excitation inductance to obtain fundamental frequency data and triple frequency data of the excitation inductance;

[0123] The inrush current is identified according to the fundamental frequency data of the excitation inductance and the triple frequency data to obtain an inrush current identification result.

[0124] In summary, the computer program product of the embodiment of the present invention first determines the excitation current according to the high-voltage side phase current and the low-voltage side phase current to further determine the excitation inductance according to the excitation current, the sampling period and the phase current, and then performs Fourier decomposition on the excitation inductance to obtain the fundamental frequency data and triple frequency data of the excitation inductance, thereby identifying the inrush current and obtaining the inrush current identification result, which has rapid and accurate identification, simple judgment conditions and is easy to implement.

[0125] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the hardware + program embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0126] The above is a description of a specific embodiment of the specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0127] Although the present application provides method operation steps as described in the embodiments or flowcharts, more or fewer operation steps may be included based on conventional or non-creative labor. The order of steps listed in the embodiments is only one way of executing the order of many steps and does not represent the only execution order. When the actual device or client product is executed, it can be executed in the order of the method shown in the embodiments or the drawings or in parallel (for example, in a parallel processor or multi-threaded processing environment).

[0128] Although the present specification embodiment provides the method operation steps as described in the embodiment or flow chart, more or less operation steps may be included based on conventional or non-creative means. The order of steps listed in the embodiment is only one way in the order of execution of many steps, and does not represent a unique execution order. When the device or terminal product in practice is executed, it can be executed in sequence or in parallel (such as a parallel processor or a multi-threaded processing environment, or even a distributed data processing environment) according to the method shown in the embodiment or the accompanying drawings. The term "include", "comprise" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, product or equipment including a series of elements not only includes those elements, but also includes other elements not clearly listed, or also includes elements inherent to such process, method, product or equipment. In the absence of more restrictions, it is not excluded that there are other identical or equivalent elements in the process, method, product or equipment including the elements.

[0129] For the convenience of description, the above devices are described in various modules according to their functions. Of course, when implementing the embodiments of this specification, the functions of each module can be implemented in the same or more software and / or hardware, or the module implementing the same function can be implemented by a combination of multiple sub-modules or sub-units. The device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0130] Those skilled in the art also know that, in addition to implementing the controller in a purely computer-readable program code, the controller can be made to implement the same function in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, such a controller can be considered as a hardware component, and the devices for implementing various functions included therein can also be considered as structures within the hardware component. Or even, the devices for implementing various functions can be considered as both software modules for implementing the method and structures within the hardware component.

[0131] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0132] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0133] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0134] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0135] The memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0136] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0137] Those skilled in the art will appreciate that the embodiments of this specification may be provided as methods, systems or computer program products. Therefore, the embodiments of this specification may take the form of complete hardware embodiments, complete software embodiments or embodiments combining software and hardware. Moreover, the embodiments of this specification may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0138] The various embodiments in this specification may be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The embodiments of this specification may also be practiced in distributed computing environments where tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules may be located in local and remote computer storage media, including storage devices.

[0139] Each embodiment in this specification is described in a progressive manner, and the same and similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. In the description of this specification, the description of the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of this specification. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0140] The above is only an example of the embodiment of the present specification and is not intended to limit the embodiment of the present specification. For those skilled in the art, the embodiment of the present specification may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiment of the present specification shall be included in the scope of the claims of the embodiment of the present specification.

Claims

1. A method for identifying a responsive flow. It is characterized in that include: Determine the excitation current according to the high-voltage side phase current and the low-voltage side phase current; Determine the excitation inductance according to the excitation current, the sampling period and the phase current; Performing Fourier decomposition on the excitation inductance to obtain fundamental frequency data and triple frequency data of the excitation inductance; The inrush current is identified according to the fundamental frequency data of the excitation inductance and the triple frequency data to obtain an inrush current identification result.

2. The method for identifying a responsive flow according to claim 1, It is characterized in that Also includes: The phase current is determined according to the high-voltage side phase current and the low-voltage side phase current.

3. The method for identifying a responsive flow according to claim 1, It is characterized in that Also includes: Determining the low-voltage side phase current according to the low-voltage side line current and the winding turns ratio; When the high voltage side of the three-phase transformer is in angle connection, the high voltage side phase current is determined according to the high voltage side line current and the circulating current in the high voltage side angle winding.

4. The method for identifying a responsive flow according to claim 2, It is characterized in that Also includes: Determine the phase voltage on the low voltage side according to the line voltage on the low voltage side and the winding turns ratio; When the high voltage side of the three-phase transformer is connected in a delta connection, the high voltage side phase voltage is determined according to the high voltage side line voltage.

5. A device for identifying a surge flow, It is characterized in that include: An excitation current determination module, used to determine the excitation current according to the high-voltage side phase current and the low-voltage side phase current; An excitation inductance determination module, used to determine the excitation inductance according to the excitation current, sampling period and phase current; A frequency data module, used for performing Fourier decomposition on the excitation inductance to obtain fundamental frequency data and triple frequency data of the excitation inductance; The combined inrush current identification module is used to identify the combined inrush current according to the fundamental frequency data of the excitation inductance and the triple frequency data to obtain the combined inrush current identification result.

6. The response flow identification device according to claim 5, It is characterized in that Also includes: The phase current determination module is used to determine the phase current according to the high-voltage side phase current and the low-voltage side phase current.

7. The response flow identification device according to claim 5, It is characterized in that Also includes: A low-voltage side phase current determination module, used to determine the low-voltage side phase current according to the low-voltage side line current and the winding turns ratio; The high-voltage side phase current determination module is used to determine the high-voltage side phase current according to the high-voltage side line current and the circulating current in the high-voltage side angle winding when the high-voltage side of the three-phase transformer is in angle connection.

8. The response flow identification device according to claim 6, It is characterized in that Also includes: A low-voltage side phase voltage determination module, used to determine the low-voltage side phase voltage according to the low-voltage side line voltage and the winding turns ratio; The high-voltage side phase voltage determination module is used to determine the high-voltage side phase voltage according to the high-voltage side line voltage when the high-voltage side of the three-phase transformer is in a delta connection.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, It is characterized in that When the processor executes the computer program, the steps of the response flow identification method described in any one of claims 1 to 4 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, It is characterized in that When the computer program is executed by a processor, the steps of the response flow identification method according to any one of claims 1 to 4 are implemented.

11. A computer program product comprising a computer program / instructions, It is characterized in that When the computer program / instructions are executed by a processor, the steps of the method for identifying the surge flow described in any one of claims 1 to 4 are implemented.

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