Intelligent tripping method for circuit breakers, computer-readable storage media and circuit breakers

Abstract

This invention provides an intelligent tripping method for circuit breakers. The intelligent tripping method includes: continuously acquiring the secondary current output by an RC integral filter unit at different operating frequencies; calibrating the secondary current based on the input-output characteristics between the primary current acquired by the Rogowski coil at different operating frequencies and the secondary current output by the RC integral filter unit at different operating frequencies to obtain a fitted primary current; the input-output characteristics between the primary current and the secondary current are correlated with the operating frequency of the current source; comparing the fitted primary current with a preset tripping threshold of the intelligent tripping system; and generating a tripping command when the primary current exceeds the preset tripping threshold. This invention also provides a computer-readable storage medium and a circuit breaker. Based on the above scheme, accurate measurement of the primary current of the circuit breaker at different operating frequencies at the front end can be achieved, realizing the Rogowski coil as a low-frequency current measurement and line protection function.

Description

Technical Field

[0001] This invention relates to the field of low-voltage electrical technology, and in particular to an intelligent tripping method for a circuit breaker, a computer-readable storage medium, and a circuit breaker. Background Technology

[0002] While Rogowski coils offer good linearity of output port voltage with respect to operating frequency in low-frequency applications, their measurement accuracy is relatively poor, making it difficult to accurately reproduce the true value of the primary current. Therefore, current technologies rarely use Rogowski coils for low-frequency (2–20 Hz) current measurement and line protection.

[0003] Therefore, how to provide an intelligent tripping method for circuit breakers, a computer-readable storage medium, and a circuit breaker to solve the defect that Rogowski coils cannot accurately reproduce the true value of the primary current in low-frequency applications has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the present invention provides an intelligent tripping method for a circuit breaker, which can accurately measure the primary current of the circuit breaker at different operating frequencies at the front end, and realize the function of measuring low-frequency (lower operating frequency) current and protecting the line using the Rogowski coil.

[0005] This invention provides an intelligent tripping method for a circuit breaker, applied to an intelligent tripping system for a circuit breaker. The input terminal of the intelligent tripping system is connected to a combined current transformer, and the output terminal is connected to a flux converter. The combined current transformer includes an energy converter and a Rogowski coil. The energy converter supplies power to the intelligent tripping system, and the Rogowski coil collects the primary-side current of the circuit breaker at different operating frequencies. The intelligent tripping system includes an RC integral filter unit and a processing unit. The input terminal of the RC integral filter unit is connected to the Rogowski coil, the output terminal of the RC integral filter unit is connected to the input terminal of the processing unit, and the output terminal of the processing unit is connected to the flux converter. The intelligent tripping method of the circuit breaker includes the following steps: continuously acquiring the secondary current output by the RC integral filter unit at different operating frequencies; calibrating the secondary current based on the input-output characteristics between the primary current acquired by the Rogowski coil at different operating frequencies and the secondary current output by the RC integral filter unit at different operating frequencies to obtain a fitted primary current; the input-output characteristics between the primary current and the secondary current are related to the operating frequency of the primary current; comparing the fitted primary current with the preset tripping threshold of the intelligent tripping system; when the fitted primary current exceeds the preset tripping threshold of the intelligent tripping system, the intelligent tripping system issues a tripping command, and the flux converter executes the tripping command.

[0006] In another illustrative embodiment of the present invention, after continuously acquiring the secondary current output by the filter unit at different operating frequencies, the intelligent tripping method further includes: calculating the operating frequency of the primary current. This step is beneficial for subsequent calibration of the primary current.

[0007] In another illustrative embodiment of the present invention, the step of calculating the operating frequency of the primary current includes: recording continuous sampling time points of the secondary current, and arbitrarily selecting a first sampling time point and a second sampling time point; wherein the second sampling time point is greater than the first sampling time point; determining a third sampling time point based on the first sampling time point and a fourth sampling time point based on the second sampling time point; wherein the third sampling time point is equal to the first sampling time point plus the sampling time interval, and the fourth sampling time point is equal to the second sampling time point plus the sampling time interval; acquiring the first output port voltage, the second output port voltage, the third output port voltage, and the fourth output port voltage output by the RC integral filter unit at the first sampling time point, the second sampling time point, the third sampling time point, and the fourth sampling time point; when the product of the first output port voltage and the third output port voltage is less than or equal to 0, and the product of the second output port voltage and the fourth output port voltage is less than or equal to 0, calculating the time interval between the corresponding second sampling time point and the first sampling time point; wherein the time interval between the second sampling time point and the first sampling time point is half a working cycle; and calculating the operating frequency of the primary current based on the working cycle. This step can accurately calculate the operating frequency of the primary current.

[0008] In another illustrative embodiment of the present invention, the input-output characteristics between the primary current acquired by the Rogowski coil at different operating frequencies and the secondary current output by the RC integral filter unit at different operating frequencies are as follows: the primary current operating frequency is the independent variable, and the current ratio between the secondary current and the primary current is the dependent variable. The response of the current ratio to the primary current operating frequency is a unit step response. Utilizing the response of the current ratio to the primary current operating frequency can improve the measurement accuracy of the primary current.

[0009] In yet another illustrative embodiment of the invention, the response of the current ratio to the primary current operating frequency is expressed as: Wherein, I2 is the secondary current output by the RC integral filter unit at different operating frequencies, I1 is the primary current collected by the Rogowski coil at different operating frequencies, f is the operating frequency of the primary current, and F is the frequency constant.

[0010] In another illustrative embodiment of the present invention, the input-output characteristics between the primary current acquired by the Rogowski coil at different operating frequencies and the secondary current output by the RC integrating filter unit at different operating frequencies are such that the modulus parameter of the amplification factor of the RC integrating filter unit is related to the RC ratio of the integrating circuit and the operating frequency. Utilizing this characteristic, the measurement accuracy of the primary current can be improved.

[0011] In another illustrative embodiment of the present invention, the modulus parameter of the amplification factor of the RC integral filter unit is the ratio of the effective value of the output port voltage of the RC integral filter unit to the effective value of the input port voltage of the RC integral filter unit, wherein the effective value of the output port voltage of the RC integral filter unit is C3*I2, C3 is a constant, and the effective value of the input port voltage of the RC integral filter unit is equal to C1*I1f, C1 is a constant.

[0012] In another aspect, the present invention provides a computer-readable storage medium storing computer-readable instructions, which, when executed by a processor, cause the processor to perform the steps in the aforementioned smart tripping method.

[0013] In another aspect, the present invention provides a circuit breaker that can use an intelligent tripping system to accurately measure the primary current at different operating frequencies at the front end of the circuit breaker, thereby enabling the Rogowski coil to measure low-frequency (lower operating frequency) current and provide line protection functions.

[0014] In another aspect, the present invention provides a circuit breaker, comprising: at least one combined current transformer, a flux converter, and an intelligent tripping system. The input terminal of the intelligent tripping system is connected to the combined current transformer, and the output terminal of the intelligent tripping system is connected to the flux converter. The combined current transformer includes an energy converter and a Rogowski coil. The energy converter supplies power to the intelligent tripping system, and the Rogowski coil is used to collect the primary-side current of the circuit breaker at different operating frequencies at the front end. The intelligent tripping system includes: an RC integral filter unit and a processing unit. The input terminal of the RC integral filter unit is connected to the Rogowski coil, and the output terminal of the RC integral filter unit is connected to the input terminal of the processing unit. The output terminal of the processing unit is connected to the flux converter. The processing unit is used to execute the steps of the intelligent tripping method described above.

[0015] In another illustrative embodiment of the present invention, the RC integral filter unit includes an RC integral low-pass filter circuit comprising at least one resistor and at least one capacitor connected to the resistor. This RC integral filter unit has a simple structure and is easy to implement. Attached Figure Description

[0016] Figure 1 This is an exemplary structural diagram of the intelligent tripping system of the circuit breaker of the present invention;

[0017] Figure 2 This is an exemplary flowchart of the intelligent tripping method for the circuit breaker of the present invention.

[0018] Figure 3 The current ratio of this invention A schematic diagram of the response to the operating frequency f of the primary current.

[0019] Figure 4 This is an exemplary hardware circuit diagram of the RC integral filter unit of the present invention.

[0020] Figure 5A This is a comparison chart of the calibration results of the primary current based on the input-output characteristics between the primary current collected by the Rogowski coil at different operating frequencies and the secondary current output by the RC integral filter unit at different operating frequencies.

[0021] Figure 5B This invention uses the input-output characteristics of the primary current acquired by the Rogowski coil at different operating frequencies and the secondary current output by the RC integral filter unit at different operating frequencies to compare the calibration results of the primary current.

[0022] List of reference numerals in the attached diagram:

[0023] 1. Intelligent tripping system for circuit breakers

[0024] 2. Combined current transformer

[0025] 3. Flux Converter

[0026] 11 RC Integral Filter Unit

[0027] 12 processing units

[0028] 21 Rogowski coil Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solutions in the embodiments of this application, the following will be combined with this application.

[0030] The accompanying drawings in the embodiments clearly and in detail describe the technical solutions in the embodiments of this application. Obviously, the described embodiments are only some embodiments of the embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art should fall within the protection scope of the embodiments of this application.

[0031] It should be understood that the terms "first," "second," and "third," etc., in the claims, specification, and drawings of this disclosure are used to distinguish different objects, not to describe a specific order. The terms "comprising" and "including" as used in the specification and claims of this disclosure indicate the presence of the described features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or sets thereof.

[0032] It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this disclosure. As used in this disclosure and claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this disclosure and claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations.

[0033] Example 1

[0034] This embodiment provides an intelligent tripping method for a circuit breaker, which is applied to, for example... Figure 1 The circuit breaker shown has an intelligent tripping system 1. The input terminal of the intelligent tripping system 1 is connected to a combined current transformer 2, and the output terminal is connected to a flux converter 3. The combined current transformer 2 includes an energy converter and a Rogowski coil 21. The energy converter is used to power the intelligent tripping system 1, and the Rogowski coil 21 is used to collect the primary current of the circuit breaker at different operating frequencies at the front end.

[0035] The intelligent tripping system 1 is used to filter the primary current signal, acquire the filtered secondary current, and calibrate the secondary current to fit the primary current. When the fitted primary current exceeds the preset tripping threshold of the intelligent tripping system 1, the intelligent tripping system issues a tripping command to the flux converter to trip.

[0036] Continue reading Figure 1 The intelligent tripping system 1 includes an RC integral filter unit 11 and a processing unit 12. The input terminal of the RC integral filter unit 11 is connected to the Rogowski coil 21, the output terminal of the RC integral filter unit 11 is connected to the input terminal of the processing unit 12, and the output terminal of the processing unit 12 is connected to the flux converter 3.

[0037] In this embodiment, the RC integral filter unit 11 is used to acquire the primary current of the circuit breaker at different operating frequencies at the front end collected by the Rogowski coil 21, and to integrate and filter the primary current to ensure the measurement accuracy at low frequencies and to ensure that high-order harmonics at high frequencies do not affect the effectiveness of the processing unit.

[0038] Please see Figure 2 This is a schematic diagram illustrating an exemplary process for a circuit breaker's intelligent tripping method. Figure 2 As shown, the intelligent tripping method includes the following steps:

[0039] S21 continuously acquires the secondary current I2 output by the RC integral filter unit at different operating frequencies.

[0040] In this embodiment, the secondary current I2 output by the RC integral filter unit at different operating frequencies is obtained by dividing the collected output port voltage V3 of the RC integral filter unit by the ratio K2 between the output current and the AD sampling input.

[0041] S23, based on the input-output characteristics between the primary current of the circuit breaker at different operating frequencies acquired by the Rogowski coil and the secondary current output by the RC integral filter unit at different operating frequencies, the second current is calibrated to obtain a fitted primary current. In this embodiment, the input-output characteristics between the primary current and the secondary current are related to the operating frequency of the primary current. In this embodiment, the input-output characteristics between the primary current of the circuit breaker at different operating frequencies acquired by the Rogowski coil and the secondary current output by the RC integral filter unit at different operating frequencies are used to reconstruct the primary current of the Rogowski coil in low-frequency applications, so as to realize the function of the Rogowski coil as a measure of low-frequency (lower operating frequency) current and for line protection.

[0042] S24, compare the fitted primary current with the preset tripping threshold of the intelligent tripping system. When the fitted primary current exceeds the preset tripping threshold of the intelligent tripping system, the intelligent tripping system issues a tripping command, and the flux converter executes the tripping command.

[0043] In this embodiment, to facilitate subsequent primary-side current calibration, such as Figure 2 As shown, after S21, the intelligent tripping method also includes:

[0044] S22, calculate the operating frequency f of the primary current.

[0045] To accurately calculate the operating frequency of the primary current, S22 specifically includes the following steps:

[0046] S221, record the continuous sampling time points of the secondary current, and arbitrarily select the first sampling time point t1 and the second sampling time point t2, wherein the second sampling time point t2 is greater than the first sampling time point t1.

[0047] S222, determine the third sampling time point t3 based on the first sampling time point t1 and the fourth sampling time point t4 based on the second sampling time point t2, wherein the third sampling time point t3 is equal to the first sampling time point t1 plus the sampling time interval Δt, and the fourth sampling time point t4 is equal to the second sampling time point t2 plus the sampling time interval Δt.

[0048] S223, acquire the first output port voltage U(t1), second output port voltage U(t2), third output port voltage U(t3), and fourth output port voltage U(t4) output by the RC integral filter unit at the first sampling time point t1, the second sampling time point t2, the third sampling time point t3, and the fourth sampling time point t4.

[0049] S224, when the product of the first output port voltage U(t1) and the third output port voltage U(t3) is less than or equal to 0, and the product of the second output port voltage U(t2) and the fourth output port voltage U(t4) is less than or equal to 0, calculate the time interval (i.e. t2-t1) between the corresponding second sampling time point t2 and the first sampling time point t1, where the time interval t2-t1 between the second sampling time point and the first sampling time point is half a working cycle.

[0050] S225, calculate the operating frequency of the primary current based on the duty cycle.

[0051] In this embodiment, when the primary current operating frequency f is the independent variable, the ratio between the primary current collected by the Rogowski coil at different operating frequencies and the secondary current output by the RC integral filter unit at different operating frequencies is defined as follows: When used as the dependent variable, current ratio The response to the primary current operating frequency f is a unit step response, such as... Figure 3 As shown.

[0052] Specifically, the response of the current ratio to the operating frequency of the primary current is expressed as:

[0053]

[0054] Where I2 is the secondary current output by the RC integral filter unit at different operating frequencies, I1 is the primary current collected by the Rogowski coil at different operating frequencies, f is the operating frequency of the primary current, and F is the frequency constant, i.e., F is A frequency equal to 0.632.

[0055] Therefore, in order to improve the measurement accuracy of the primary current, the input-output characteristics between the primary current of the circuit breaker at different operating frequencies collected by the Rogowski coil and the secondary current output by the RC integral filter unit at different operating frequencies are as follows: the operating frequency of the primary current is the independent variable, the current ratio between the secondary current and the primary current is the dependent variable, and the response of the current ratio to the operating frequency of the primary current is a unit step response. In this embodiment, S23 uses formula (1) to calibrate the secondary current I2 output by the RC integral filter unit at different operating frequencies to fit the primary current collected by the Rogowski coil at different operating frequencies.

[0056] In this embodiment, the source current Where I1 is the primary current at different operating frequencies of the front end collected by the Rogowski coil, and ω = 2πf.

[0057] Input port voltage of RC integral filter unit The formula can be simplified as follows: C1 is a constant, that is n is the number of turns of the Rogowski coil, A is the cross-sectional area of ​​the Rogowski coil, and μ0 is the permeability of free space.

[0058] Furthermore, because the output port voltage of the RC integral filter unit The formula can be simplified as follows: C3 is a constant, that is K2 is the ratio between the output current and the AD sampling input, and it is a fixed value.

[0059] In this embodiment, by comparing the output port voltage V3 of the RC integral filter unit with the input port voltage V1 of the RC integral filter unit, the relationship between the secondary current I2 output by the RC integral filter unit at different operating frequencies and the primary current I1 of the front end sampled by the Rogowski coil at different operating frequencies can be obtained, i.e. and This can be obtained by calculating the modulus parameter of the amplification factor of the RC integral filter unit, i.e. equal For example, such as Figure 4 In the exemplary hardware circuit of the RC integral filter unit shown, the RC integral filter unit 11 includes an RC integral low-pass filter circuit, which includes resistors R1 and R2, and a filter capacitor C4. Therefore, the modulus parameter of the amplification factor of the RC integral filter unit... in,

[0060] Therefore, in order to improve the measurement accuracy of the primary current, the input-output characteristics between the primary current acquired by the Rogowski coil at different operating frequencies and the secondary current output by the RC integrating filter unit at different operating frequencies are as follows: When the modulus parameter of the amplification factor of the RC integrating filter unit is related to the RC of the integrating circuit and the operating frequency, it can be expressed by the following formula:

[0061] The secondary current I2 output by the RC integral filter unit at different operating frequencies is calibrated to fit the primary current at different operating frequencies collected by the Rogowski coil. Among them, the modulus parameter of the amplification factor of the RC integral filter unit. C3 is the ratio of the effective value of the output port voltage of the RC integral filter unit to the effective value of the input port voltage of the RC integral filter unit. The effective value of the output port voltage of the RC integral filter unit is C3*I2, where C3 is a constant, and the effective value of the input port voltage of the RC integral filter unit is equal to C1*I1f, where C1 is a constant.

[0062] Please see Figure 5A and Figure 5B The figures show a comparison of the calibration results of the primary current based on the input-output characteristics of the primary current at different operating frequencies acquired by the Rogowski coil and the secondary current output by the RC integral filter unit at different operating frequencies. Figure 5A As shown, under different operating frequencies with a constant primary current, the calibration current curve A is basically close to the primary current curve B. Figure 5B As shown, under different operating frequencies, the calibration current value D curve is basically close to the primary current C curve. This means that the intelligent tripping method provided by this invention can achieve accurate measurement of the primary current at different operating frequencies, from low frequency 2-20Hz to normal operating frequency 50 / 60Hz or even higher.

[0063] This application also proposes a computer-readable storage medium storing computer-readable instructions, which, when executed by a processor, cause the processor to perform the steps in the aforementioned intelligent tripping method for a circuit breaker.

[0064] At any possible level of technical detail, this application can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of this application.

[0065] Computer-readable storage media can be tangible devices capable of holding and storing instructions for use by an instruction execution device. Computer-readable storage media can be, for example, (but not limited to) electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination of the foregoing. The computer-readable storage media used herein are not to be construed as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0066] The computer-readable program described herein can be downloaded from a computer-readable storage medium to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives computer-readable program instructions from the network and forwards these instructions to a computer-readable storage medium in the respective computing / processing device. The computer program instructions used to perform the operations of this application may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, status setting data, integrated circuit configuration data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and procedural programming languages ​​such as "C" or similar programming languages. Computer-readable program instructions may execute entirely on a user's computer, partially on a user's computer, as a standalone software package, partially on a user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing state information from the computer-readable program instructions. This electronic circuitry can execute the computer-readable program instructions to implement various aspects of this application.

[0067] Example 2

[0068] This embodiment proposes a circuit breaker, which includes at least one combined current transformer 2, a flux converter 3, and an intelligent tripping system 1. The input terminal of the intelligent tripping system 1 is connected to the combined current transformer 2, and the output terminal of the intelligent tripping system 1 is connected to the flux converter 3. The combined current transformer 2 includes an energy converter and a Rogowski coil 21. The energy converter supplies power to the intelligent tripping system 1, and the Rogowski coil 21 is used to collect the primary current of the circuit breaker at different operating frequencies at the front end. The intelligent tripping system 1 includes an RC integral filter unit 11 and a processing unit 12. The input terminal of the RC integral filter unit 11 is connected to the Rogowski coil 21, the output terminal of the RC integral filter unit 11 is connected to the input terminal of the processing unit 12, and the output terminal of the processing unit 12 is connected to the flux converter 3.

[0069] The RC integral filter unit 11 is used to acquire the primary current of the circuit breaker at different operating frequencies at the front end collected by the Rogowski coil 21, and to integrate and filter the primary current to ensure the measurement accuracy at low frequencies and to ensure that high-order harmonics at high frequencies do not affect the effectiveness of the processing unit.

[0070] In this embodiment, in order to achieve a simple structure and ease of implementation, such as Figure 4 As shown, the RC integral filter unit 11 includes an RC integral low-pass filter circuit, which includes at least one resistor R and at least one capacitor C connected to the resistor R.

[0071] Processing unit 12 is used to perform the steps in the intelligent tripping method for the circuit breaker as described in Embodiment 1. The processing unit may include a microprocessor, application-specific integrated circuit (ASIC), digital signal processor (DSP), central processing unit (CPU), graphics processing unit (GPU), state machine, etc. Embodiments of computer-readable media include, but are not limited to, floppy disks, CD-ROMs, magnetic disks, memory chips, ROMs, RAMs, ASICs, configured processors, all-optical media, all magnetic tapes or other magnetic media, or any other media from which a computer processor can read instructions. Furthermore, various other forms of computer-readable media can send or carry instructions to a computer, including routers, private or public networks, or other wired and wireless transmission devices or channels. Instructions may include code in any computer programming language, including C, C++, C++, Visual Basic, Java, and JavaScript.

[0072] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application. The nouns and pronouns referring to persons in this patent application are not limited to specific genders.

Claims

1. A method for intelligent tripping of a circuit breaker, characterized in that, An intelligent tripping system (1) applied to a circuit breaker has its input end connected to a combined current transformer (2) and its output end connected to a flux converter (3). The combined current transformer (2) includes an energy converter and a Rogowski coil (21). The energy converter is used to power the intelligent tripping system (1), and the Rogowski coil (21) is used to collect the primary current of the circuit breaker at different operating frequencies at the front end. The intelligent tripping system (1) includes an RC integral filter unit (11) and a processing unit (12). The input end of the RC integral filter unit (11) is connected to the Rogowski coil (21), the output end of the RC integral filter unit (11) is connected to the input end of the processing unit (12), and the output end of the processing unit (12) is connected to the flux converter (3). The intelligent tripping method of the circuit breaker includes the following steps: The secondary current output by the RC integral filter unit at different operating frequencies is continuously collected; Based on the input-output characteristics between the primary current at different operating frequencies acquired by the Rogowski coil and the secondary current output by the RC integral filter unit at different operating frequencies, the secondary current is calibrated to obtain a fitted primary current; the input-output characteristics between the primary current and the secondary current are related to the operating frequency of the primary current. The fitted primary current is compared with the preset tripping threshold of the intelligent tripping system (1). When the fitted primary current exceeds the preset tripping threshold of the intelligent tripping system (1), the intelligent tripping system (1) generates a tripping command, and the flux converter (3) performs the tripping operation.

2. The intelligent tripping method for a circuit breaker according to claim 1, characterized in that, After continuously acquiring the secondary current output by the filter unit at different operating frequencies, the intelligent tripping method further includes: Calculate the operating frequency of the primary current.

3. The intelligent tripping method for a circuit breaker according to claim 2, characterized in that, The steps for calculating the operating frequency of the primary current include: Record the continuous sampling time points of the secondary current, and arbitrarily select the first sampling time point and the second sampling time point from them; wherein the second sampling time point is greater than the first sampling time point; A third sampling time point is determined based on the first sampling time point, and a fourth sampling time point is determined based on the second sampling time point; wherein, the third sampling time point is equal to the first sampling time point plus the sampling time interval, and the fourth sampling time point is equal to the second sampling time point plus the sampling time interval; The first output port voltage, the second output port voltage, the third output port voltage, and the fourth output port voltage of the RC integral filter unit are obtained at the first sampling time point, the second sampling time point, the third sampling time point, and the fourth sampling time point; When the product of the voltage at the first output port and the voltage at the third output port is less than or equal to 0, and the product of the voltage at the second output port and the voltage at the fourth output port is less than or equal to 0, calculate the time interval between the corresponding second sampling time point and the first sampling time point; wherein, the time interval between the second sampling time point and the first sampling time point is half a working cycle. The operating frequency of the primary current is calculated based on the duty cycle.

4. The intelligent tripping method for a circuit breaker according to claim 3, characterized in that, The input-output characteristics between the primary current at different operating frequencies acquired by the Rogowski coil and the secondary current output by the RC integral filter unit at different operating frequencies are as follows: the operating frequency of the primary current is the independent variable, the current ratio between the secondary current and the primary current is the dependent variable, and the response of the current ratio to the operating frequency of the primary current is a unit step response.

5. The intelligent tripping method for a circuit breaker according to claim 4, characterized in that, The response of the current ratio to the operating frequency of the primary current is expressed as: Wherein, I2 is the secondary current output by the RC integral filter unit at different operating frequencies, I1 is the primary current collected by the Rogowski coil at different operating frequencies, f is the operating frequency of the primary current, and F is the frequency constant.

6. The intelligent tripping method according to claim 3, characterized in that, The input-output characteristics between the primary current collected by the Rogowski coil at different operating frequencies and the secondary current output by the RC integral filter unit at different operating frequencies are related to the modulus parameter of the amplification factor of the RC integral filter unit, the RC of the integral circuit, and the operating frequency.

7. The intelligent tripping method for a circuit breaker according to claim 6, characterized in that, The modulus parameter of the amplification factor of the RC integral filter unit is the ratio of the effective value of the output port voltage of the RC integral filter unit to the effective value of the input port voltage of the RC integral filter unit. The effective value of the output port voltage of the RC integral filter unit is C3*I2, where C3 is the constant value, and the effective value of the input port voltage of the RC integral filter unit is equal to C1*I1f, where C1 is the constant value.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-readable instructions, which, when executed by a processor, cause the processor to perform the steps of the smart tripping method as described in any one of claims 1 to 7.

9. A circuit breaker, characterized in that, include: The circuit includes at least one combined current transformer (2), one flux converter (3), and one intelligent tripping system (1). The input terminal of the intelligent tripping system (1) is connected to the combined current transformer (2), and the output terminal of the intelligent tripping system (1) is connected to the flux converter (3). The combined current transformer (2) includes an energy converter and a Rogowski coil (21). The energy converter is used to supply power to the intelligent tripping system (1), and the Rogowski coil (21) is used to collect the primary current of the circuit breaker at different operating frequencies at the front end. The intelligent tripping system (1) includes: An RC integral filter unit (11) and a processing unit (12) are provided, wherein the input terminal of the RC integral filter unit (11) is connected to the Rogowski coil (21), the output terminal of the RC integral filter unit (11) is connected to the input terminal of the processing unit (12), and the output terminal of the processing unit (12) is connected to the flux converter (3). The processing unit (12) is used to perform the steps in the intelligent tripping method as described in any one of claims 1 to 8.

10. The circuit breaker according to claim 9, characterized in that, The RC integral filter unit (11) includes an RC integral low-pass filter circuit comprising at least one resistor and at least one capacitor connected to the resistor.

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