Electric leakage detection circuit, reclosing device and circuit breaker

Abstract

The utility model relates to the technical field of electric leakage detection, and discloses an electric leakage detection circuit, a reclosing device and a circuit breaker, the electric leakage detection circuit comprises a signal input module, a two-way differential rectification module, a filtering module, an in-phase amplification module and a steady state output module which are connected in sequence; the signal input module is connected with a tested line, and the steady state output module is connected with the single-chip microcomputer. The signal input module is used for receiving alternating current signals; the double-path differential rectification module is used for converting an alternating current signal into two paths of differential signals, respectively rectifying the two paths of differential signals and outputting a first direct current signal; the filtering module is used for filtering the first direct-current signal to obtain a second direct-current signal; the in-phase amplification module is used for amplifying the second direct current signal to obtain a third direct current signal; and the steady-state output module is used for converting the third direct-current signal into a monostable pulse signal, so that the single chip microcomputer determines whether the detected circuit leaks electricity or not according to the monostable pulse signal. The electric leakage detection circuit can accurately detect the electric leakage phenomenon and effectively avoid false operation of reclosing.

Description

Technical Field

[0001] The present application relates to the technical field of leakage detection, and in particular to a leakage detection circuit, a reclosing device and a circuit breaker. Background Art

[0002] Circuit breakers can detect leakage in circuits and immediately cut off power to prevent electric shock. Reclosing allows circuit breakers to automatically reclose and restore power after the circuit breaker opens if the leakage fault has been resolved. This function is crucial for improving power supply reliability and reducing power outages. However, due to complex loads, existing reclosing devices cannot accurately determine whether the leakage fault has been resolved, leading to incorrect reclosing of the circuit breaker, causing circuit failures or damage to electrical equipment, increasing repair costs. Alternatively, if the leakage fault has been resolved, the circuit breaker cannot be reclosed, causing unnecessary outages. Utility Model Content

[0003] In view of this, the embodiments of the present application provide a leakage detection circuit, a reclosing device and a circuit breaker, which can accurately detect the leakage condition of the tested line, and solve the problem that traditional reclosing cannot accurately determine whether the leakage fault has been eliminated.

[0004] In a first aspect, an embodiment of the present application provides a leakage detection circuit, comprising a signal input module, a dual-path differential rectifier module, a filter module, a non-inverting amplifier module, and a steady-state output module;

[0005] The first end of the signal input module is connected to the circuit under test, the second end of the signal input module is connected to the first end of the dual-path differential rectifier module, the second end of the dual-path differential rectifier module is connected to the first end of the filter module, the second end of the filter module is connected to the first end of the in-phase amplifier module, the second end of the in-phase amplifier module is connected to the first end of the steady-state output module, and the second end of the steady-state output module is connected to the single-chip microcomputer;

[0006] The signal input module is used to receive the AC signal of the tested circuit;

[0007] The dual-path differential rectifier module is used to convert the AC signal into two differential signals and perform rectification on each of them, and then output a first DC signal after connecting the two differential signals in parallel;

[0008] The filtering module is used to remove clutter in the first DC signal to obtain the required second DC signal;

[0009] The in-phase amplification module is used to amplify the second DC signal to obtain a third DC signal;

[0010] The steady-state output module is used to convert the third DC signal into a monostable pulse signal and output it to the single-chip microcomputer;

[0011] The single chip microcomputer is used to determine whether the tested circuit has leakage according to the monostable pulse signal.

[0012] In a first possible implementation manner of the first aspect, the single chip microcomputer is specifically configured to determine that the measured circuit is leaking when detecting that the voltage of the monostable pulse signal is greater than or equal to a preset voltage;

[0013] When it is detected that the voltage of the monostable pulse signal is less than the preset voltage, it is determined that the circuit under test has no leakage.

[0014] In a second possible implementation manner of the first aspect, the signal input module includes a first RC network unit, a first diode, and a second diode;

[0015] The cathode of the first diode is connected to the anode of the second diode, and a series node of the cathode of the first diode and the anode of the second diode is connected to the first end of the measured circuit and the first input end of the first RC network unit respectively;

[0016] The anode of the first diode is connected to the second end of the measured circuit and the second input end of the first RC network unit respectively, and the cathode of the second diode is connected to the second end of the measured circuit and the second input end of the first RC network unit respectively;

[0017] The first output terminal and the second output terminal of the first RC network unit are respectively connected to the dual-path differential rectifier module, and the third output terminal of the first RC network unit is grounded.

[0018] In a third possible implementation of the first aspect, the dual-path differential rectifier module includes two groups of differential amplification units;

[0019] The input end of each group of the differential amplification units is respectively connected to the signal input module, and the output end of each group of the differential amplification units is connected to the filtering module; the two groups of the differential amplification units are respectively used to rectify the differential signals of their own paths into pulsating DC signals, and at the same time merge the pulsating DC signals into the first DC signal.

[0020] In a fourth possible implementation of the first aspect, each group of the differential amplification units includes a first resistor, a second resistor, a third resistor, a fourth resistor, a rectifier, and a first voltage regulator diode;

[0021] The first end of the first resistor is connected to the signal input module, the second end of the first resistor is respectively connected to the first end of the second resistor and the inverting input end of the rectifier, the second end of the second resistor is connected to the output end of the rectifier, the output end of the rectifier is connected to the anode of the first Zener diode, and the cathode of the first Zener diode is connected to the filtering module;

[0022] The first end of the third resistor is connected to the signal input module, the second end of the third resistor is respectively connected to the first end of the fourth resistor and the non-inverting input end of the rectifier, and the second end of the fourth resistor is grounded.

[0023] In a fifth possible implementation of the first aspect, the filtering module includes a second RC network unit; the input end of the second RC network unit is connected to the dual-path differential rectifier module, and the output end of the second RC network unit is connected to the in-phase amplification module.

[0024] In a sixth possible implementation of the first aspect, the in-phase amplification module includes a fifth resistor, a sixth resistor, and a first operational amplifier;

[0025] a first end of the fifth resistor connected to the first output end of the second RC network unit, a second end of the fifth resistor connected to the first end of the sixth resistor and the inverting input end of the first operational amplifier, respectively, and a second end of the sixth resistor connected to the output end of the first operational amplifier;

[0026] The output end of the first operational amplifier is connected to the steady-state output module, and the non-inverting input end of the first operational amplifier is connected to the second output end of the second RC network unit.

[0027] In a seventh possible implementation of the first aspect, the steady-state output module includes a seventh resistor, an eighth resistor, a first capacitor, a second capacitor, a second voltage stabilizing diode, and a second operational amplifier;

[0028] A first end of the seventh resistor is connected to the in-phase amplifier module, a second end of the seventh resistor is connected to a first end of the eighth resistor, and a second end of the eighth resistor is connected to the single chip microcomputer;

[0029] The series connection node of the seventh resistor and the eighth resistor is connected to the first end of the first capacitor and the cathode of the second voltage zener diode respectively, and the parallel connection node of the second end of the first capacitor and the anode of the second voltage zener diode is connected to the non-inverting input terminal, the inverting input terminal and the negative power supply terminal of the second operational amplifier respectively;

[0030] The positive power supply terminal of the second operational amplifier is connected to a power supply and a first terminal of the second capacitor respectively, and the second terminal of the second capacitor is grounded;

[0031] A parallel node of the second end of the first capacitor and the anode of the second voltage stabilizing diode, a non-inverting input terminal, an inverting input terminal and a negative power supply terminal of the second operational amplifier are all grounded.

[0032] In a second aspect, an embodiment of the present application provides a reclosing device, comprising the above-mentioned leakage detection circuit.

[0033] In a third aspect, an embodiment of the present application provides a circuit breaker comprising the above-mentioned reclosing device.

[0034] The embodiments of the present application have the following beneficial effects:

[0035] The leakage detection circuit of the embodiment of the present application includes a signal input module, a dual-channel differential rectifier module, a filtering module, a common-mode amplifier module and a steady-state output module connected in sequence; the signal input module is connected to the circuit under test, and the steady-state output module is connected to the single-chip microcomputer; the signal input module is used to receive an AC signal; the dual-channel differential rectifier module is used to convert the AC signal into two differential signals and rectify them respectively, and output a first DC signal; the filtering module is used to filter the first DC signal to obtain a second DC signal; the common-mode amplifier module is used to amplify the second DC signal to obtain a third DC signal; the steady-state output module is used to convert the third DC signal into a monostable pulse signal, so that the single-chip microcomputer determines whether the circuit under test has leakage according to the monostable pulse signal. Based on the above scheme, the present application realizes more accurate and flexible leakage detection by rectifying, filtering, amplifying and steadily converting the leakage AC signal into a monostable pulse signal output in sequence, effectively avoiding the malfunction and underreporting of the circuit breaker by the reclosing switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solution of this application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of this application and should not be regarded as limiting the scope of protection of this application. In each of the drawings, similar components are numbered similarly.

[0037] Figure 1 A first structural diagram of a leakage monitoring circuit according to an embodiment of the present application is shown;

[0038] Figure 2 A second structural diagram of the leakage monitoring circuit according to an embodiment of the present application is shown;

[0039] Figure 3 A circuit diagram of a leakage monitoring circuit according to an embodiment of the present application is shown.

[0040] Description of main component symbols:

[0041] 100-leakage detection circuit; 110-signal input module; 120-dual-channel differential rectifier module; 130-filter module; 140-common-phase amplifier module; 150-steady-state output module; 160-single-chip microcomputer. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0043] The components of the embodiments of the present application generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but rather merely represents selected embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort are within the scope of protection of the present application.

[0044] Hereinafter, the terms "including", "having" and their cognates, which may be used in various embodiments of the present application, are intended only to indicate specific features, numbers, steps, operations, elements, components or combinations of the foregoing items, and should not be understood as first excluding the existence of one or more other features, numbers, steps, operations, elements, components or combinations of the foregoing items or the possibility of adding one or more features, numbers, steps, operations, elements, components or combinations of the foregoing items.

[0045] Furthermore, the terms “first,” “second,” “third,” etc., are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0046] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which the various embodiments of the present application belong. The terms (such as those defined in generally used dictionaries) will be interpreted as having the same meaning as in the context of the relevant technical field and will not be interpreted as having an idealized meaning or an overly formal meaning unless clearly defined in the various embodiments of the present application.

[0047] In the embodiment of the present application, the leakage detection circuit 100 simultaneously implements the functions of rectifying, filtering, amplifying, and outputting a monostable pulse signal in a stable state for an AC signal within the same circuit, thereby improving signal quality and stability. This allows the microcontroller 160 to easily detect leakage based on the monostable pulse signal obtained after signal processing. The leakage detection circuit 100 can be applied to reclosing devices to accurately detect leakage, thereby promptly controlling the reclosing or continuous opening of the circuit breaker.

[0048] Please refer to Figure 1 , which is a schematic structural diagram of a leakage detection circuit 100 provided in an embodiment of the present application. Exemplarily, the leakage detection circuit 100 includes a signal input module 110, a dual-path differential rectifier module 120, a filter module 130, a non-inverting amplifier module 140, and a steady-state output module 150. The signal input module 110, the dual-path differential rectifier module 120, the filter module 130, the non-inverting amplifier module 140, and the steady-state output module 150 are sequentially connected to convert an input AC signal into a monostable pulse signal, enabling the single-chip microcomputer 160 to more clearly identify the monostable pulse signal and determine whether the circuit under test has leakage.

[0049] In this embodiment, the first end of the signal input module 110 is connected to the circuit under test, the second end of the signal input module 110 is connected to the first end of the dual-path differential rectifier module 120, the second end of the dual-path differential rectifier module 120 is connected to the first end of the filter module 130, the second end of the filter module 130 is connected to the first end of the in-phase amplifier module 140, the second end of the in-phase amplifier module 140 is connected to the first end of the steady-state output module 150, and the second end of the steady-state output module 150 is connected to the single-chip microcomputer 160; the signal input module 110 is used to receive the AC signal of the circuit under test ; The dual-path differential rectifier module 120 is used to convert the AC signal into two differential signals and rectify them separately, and connect the two differential signals in parallel to output a first DC signal; the filtering module 130 is used to remove the noise in the first DC signal to obtain the required second DC signal; the in-phase amplifier module 140 is used to amplify the second DC signal to obtain a third DC signal; the steady-state output module 150 is used to convert the third DC signal into a monostable pulse signal and output it to the microcontroller 160; the microcontroller 160 is used to determine whether the tested circuit has leakage according to the monostable pulse signal.

[0050] It can be understood that the leakage detection circuit 100 not only converts AC power into DC power through the process of rectifying, filtering, amplifying and steadily outputting the AC signal, but also removes high-frequency noise and harmonics through the filtering module 130, increases the signal amplitude through the in-phase amplification module 140, and obtains a stable monostable pulse signal output through the steady-state output module 150. The monostable pulse signal has high stability and low noise, and is used for accurate leakage detection.

[0051] For example, in one embodiment, Figure 2 As shown, the single-chip microcomputer 160 is specifically configured to determine that the circuit under test has leakage when the voltage of the monostable pulse signal detected is greater than or equal to a preset voltage; and to determine that the circuit under test has no leakage when the voltage of the monostable pulse signal detected is less than the preset voltage. It will be understood that the preset voltage can be set accordingly based on actual application conditions.

[0052] In order to better understand the leakage detection circuit 100, the various components of the leakage detection circuit 100 are described in detail below. Figure 3 , which is a schematic diagram of a circuit structure of a leakage detection circuit 100 provided in an embodiment of the present application.

[0053] In one embodiment, the signal input module 110 includes a first RC network unit 111, a first diode D1, and a second diode D2; the cathode of the first diode D1 is connected to the anode of the second diode D2, and the series node of the cathode of the first diode D1 and the anode of the second diode D2 is respectively connected to the first end of the measured circuit and the first input end of the first RC network unit 111; the anode of the first diode D1 is respectively connected to the second end of the measured circuit and the second input end of the first RC network unit 111, and the cathode of the second diode D2 is respectively connected to the second end of the measured circuit and the second input end of the first RC network unit 111; the first output end and the second output end of the first RC network unit 111 are respectively connected to the dual-path differential rectifier module 120, and the third output end of the first RC network unit 111 is grounded.

[0054] Optionally, the first RC network unit 111 can be implemented using a first current limiting resistor R9, a second current limiting resistor R10, a third current limiting resistor R11, a fourth current limiting resistor R12, a first filter capacitor C3, and a second filter capacitor C4; specifically, the first end of the first current limiting resistor R9 is respectively connected to the series node of the cathode of the first diode D1 and the anode of the second diode D2, and the first end of the second current limiting resistor R10, and the second end of the first current limiting resistor R9 is connected to the first end of the first filter capacitor C3; the first end of the third current limiting resistor R11 is respectively connected to the anode of the first diode D1, the cathode of the second diode D2, and the first end of the fourth current limiting resistor R12, the second end of the fourth current limiting resistor R12 is connected to the first end of the second filter capacitor C4, and the series node of the second end of the second current limiting resistor R10 and the second end of the third current limiting resistor R11, and the series node of the second end of the first filter capacitor C3 and the second end of the second filter capacitor C4 are grounded.

[0055] In one embodiment, the dual-path differential rectifier module 120 includes two groups of differential amplification units 121; the input end of each group of differential amplification units 121 is respectively connected to the signal input module 110, and the output end of each group of differential amplification units 121 is connected to the filtering module 130; the two groups of differential amplification units 121 are respectively used to rectify the differential signals of their own paths into pulsating DC signals, and then merge the two obtained pulsating DC signals into one signal, which is recorded here as the first DC signal.

[0056] In one embodiment, each group of differential amplification units 121 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a rectifier U1 and a first Zener diode D3; the first end of the first resistor R1 is connected to the signal input module 110, the second end of the first resistor R1 is respectively connected to the first end of the second resistor R2 and the inverting input end of the rectifier U1, the second end of the second resistor R2 is connected to the output end of the rectifier U1, the output end of the rectifier U1 is connected to the anode of the first Zener diode D3, and the cathode of the first Zener diode D3 is connected to the filtering module 130; the first end of the third resistor R3 is connected to the signal input module 110, the second end of the third resistor R3 is respectively connected to the first end of the fourth resistor R4 and the non-inverting input end of the rectifier U1, and the second end of the fourth resistor R4 is grounded.

[0057] Exemplarily, the first end of the first resistor R1 is used to connect the series node of the first current limiting resistor R9 and the first filter capacitor C3, and the first end of the third resistor R3 is used to connect the series node of the fourth current limiting resistor R12 and the second filter capacitor C4.

[0058] In one embodiment, the filtering module 130 includes a second RC network unit 131 ; an input end of the second RC network unit 131 is connected to the dual-path differential rectifier module 120 , and an output end of the second RC network unit 131 is connected to the in-phase amplifier module 140 .

[0059] Optionally, the second RC network unit 131 can be implemented using a fifth current limiting resistor R13, a sixth current limiting resistor R14, a third filter capacitor C5 and a fourth filter capacitor C6. Specifically, the first end of the fifth current limiting resistor R13 is used to connect the parallel node of the two groups of differential amplification units 121, the first end of the sixth current limiting resistor R14 and the first end of the third filter capacitor C5, respectively, and the second end of the fifth current limiting resistor R13 is connected to the first end of the fourth filter capacitor C6; the second end of the fifth current limiting resistor R13, the second end of the third filter capacitor C5 and the second end of the fourth filter capacitor C6 are all grounded.

[0060] In one embodiment, the non-inverting amplifier module 140 includes a fifth resistor R5, a sixth resistor R6 and a first operational amplifier U2; the first end of the fifth resistor R5 is connected to the first output end of the second RC network unit 131, the second end of the fifth resistor R5 is respectively connected to the first end of the sixth resistor R6 and the inverting input end of the first operational amplifier U2, and the second end of the sixth resistor R6 is connected to the output end of the first operational amplifier U2; the output end of the first operational amplifier U2 is connected to the steady-state output module 150, and the non-inverting input end of the first operational amplifier U2 is connected to the second output end of the second RC network unit 131.

[0061] In one embodiment, the first end of the fifth resistor R5 is connected to the parallel node of the fifth current limiting resistor R13, the third filter capacitor C5 and the fourth filter capacitor C6; the non-inverting input end of the first operational amplifier U2 is connected to the series node of the sixth current limiting resistor R14 and the fourth filter capacitor.

[0062] In one embodiment, the steady-state output module 150 includes a seventh resistor R7, an eighth resistor R8, a first capacitor C1, a second capacitor C2, a second voltage-stabilizing diode D4, and a second operational amplifier U3; the first end of the seventh resistor R7 is connected to the non-inverting amplifier module 140, the second end of the seventh resistor R7 is connected to the first end of the eighth resistor R8, and the second end of the eighth resistor R8 is connected to the single-chip microcomputer 160; the series node of the seventh resistor R7 and the eighth resistor R8 is respectively connected to the first end of the first capacitor C1 and the cathode of the second voltage-stabilizing diode D4, and the parallel node of the second end of the first capacitor C1 and the anode of the second voltage-stabilizing diode D4 is respectively connected to the non-inverting input terminal, the inverting input terminal, and the negative power supply terminal of the second operational amplifier U3; the positive power supply terminal of the second operational amplifier U3 is respectively connected to the power supply VCC and the first end of the second capacitor C2, and the second end of the second capacitor C2 is grounded; the parallel node of the second end of the first capacitor C1 and the anode of the second voltage-stabilizing diode D4, the non-inverting input terminal, the inverting input terminal, and the negative power supply terminal of the second operational amplifier U3 are all grounded.

[0063] The present application also proposes a reclosing device for reclosing the circuit breaker after the leakage fault of the tested circuit is eliminated, which can quickly restore the power supply of the tested circuit, thereby improving the reliability and continuity of the circuit. Exemplarily, the reclosing device includes the leakage detection circuit 100 of the above embodiment. It should be understood that the leakage detection circuit 100 of this embodiment can exist independently in the form of a packaged circuit module, or can be part of the above-mentioned reclosing device, that is, arranged inside the reclosing device, which is not limited here.

[0064] This application also proposes a circuit breaker for use in electrical equipment such as power systems, industrial production, and household electrical appliances. The circuit breaker is primarily used to protect circuits and electrical equipment from abnormal operating conditions, such as circuit overloads or short circuits, which could lead to safety accidents. Exemplarily, the circuit breaker includes a reclosing device as described in the above-described embodiment.

[0065] The above is only a specific implementation method of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed in this application, which should be covered by the protection scope of the present application.

Claims

1. A leakage detection circuit, characterized in that: It includes a signal input module, a dual-channel differential rectification module, a filtering module, a common-mode amplifier module and a steady-state output module; The first end of the signal input module is connected to the circuit under test, the second end of the signal input module is connected to the first end of the dual-path differential rectifier module, the second end of the dual-path differential rectifier module is connected to the first end of the filter module, the second end of the filter module is connected to the first end of the in-phase amplifier module, the second end of the in-phase amplifier module is connected to the first end of the steady-state output module, and the second end of the steady-state output module is connected to the single-chip microcomputer; The signal input module is used to receive the AC signal of the tested circuit; The dual-path differential rectifier module is used to convert the AC signal into two differential signals and perform rectification on each of them, and then output a first DC signal after connecting the two differential signals in parallel; The filtering module is used to remove clutter in the first DC signal to obtain the required second DC signal; The in-phase amplification module is used to amplify the second DC signal to obtain a third DC signal; The steady-state output module is used to convert the third DC signal into a monostable pulse signal and output it to the single-chip microcomputer; The single chip microcomputer is used to determine whether the tested circuit has leakage according to the monostable pulse signal.

2. The leakage detection circuit according to claim 1, characterized in that: The single chip microcomputer is specifically configured to determine that the tested circuit has leakage when detecting that the voltage of the monostable pulse signal is greater than or equal to a preset voltage; When it is detected that the voltage of the monostable pulse signal is less than the preset voltage, it is determined that the circuit under test has no leakage.

3. The leakage detection circuit according to claim 1, wherein: The signal input module includes a first RC network unit, a first diode and a second diode; The cathode of the first diode is connected to the anode of the second diode, and a series node of the cathode of the first diode and the anode of the second diode is connected to the first end of the measured circuit and the first input end of the first RC network unit respectively; The anode of the first diode is connected to the second end of the measured circuit and the second input end of the first RC network unit respectively, and the cathode of the second diode is connected to the second end of the measured circuit and the second input end of the first RC network unit respectively; The first output terminal and the second output terminal of the first RC network unit are respectively connected to the dual-path differential rectifier module, and the third output terminal of the first RC network unit is grounded.

4. The leakage detection circuit according to claim 1, wherein: The dual-path differential rectifier module includes two groups of differential amplification units; The input end of each group of the differential amplification units is respectively connected to the signal input module, and the output end of each group of the differential amplification units is connected to the filtering module; the two groups of the differential amplification units are respectively used to rectify the differential signals of their own paths into pulsating DC signals, and at the same time merge the pulsating DC signals into the first DC signal.

5. The leakage detection circuit according to claim 4, characterized in that: Each group of the differential amplification units includes a first resistor, a second resistor, a third resistor, a fourth resistor, a rectifier and a first voltage stabilizing diode; The first end of the first resistor is connected to the signal input module, the second end of the first resistor is respectively connected to the first end of the second resistor and the inverting input end of the rectifier, the second end of the second resistor is connected to the output end of the rectifier, the output end of the rectifier is connected to the anode of the first Zener diode, and the cathode of the first Zener diode is connected to the filtering module; The first end of the third resistor is connected to the signal input module, the second end of the third resistor is respectively connected to the first end of the fourth resistor and the non-inverting input end of the rectifier, and the second end of the fourth resistor is grounded.

6. The leakage detection circuit according to claim 1, wherein: The filtering module includes a second RC network unit; the input end of the second RC network unit is connected to the dual-path differential rectifier module, and the output end of the second RC network unit is connected to the in-phase amplification module.

7. The leakage detection circuit according to claim 6, characterized in that: The in-phase amplification module includes a fifth resistor, a sixth resistor and a first operational amplifier; a first end of the fifth resistor connected to the first output end of the second RC network unit, a second end of the fifth resistor connected to the first end of the sixth resistor and the inverting input end of the first operational amplifier, respectively, and a second end of the sixth resistor connected to the output end of the first operational amplifier; The output end of the first operational amplifier is connected to the steady-state output module, and the non-inverting input end of the first operational amplifier is connected to the second output end of the second RC network unit.

8. The leakage detection circuit according to claim 1, wherein: The steady-state output module includes a seventh resistor, an eighth resistor, a first capacitor, a second capacitor, a second voltage-stabilizing diode, and a second operational amplifier; A first end of the seventh resistor is connected to the in-phase amplifier module, a second end of the seventh resistor is connected to a first end of the eighth resistor, and a second end of the eighth resistor is connected to the single chip microcomputer; The series connection node of the seventh resistor and the eighth resistor is connected to the first end of the first capacitor and the cathode of the second voltage zener diode respectively, and the parallel connection node of the second end of the first capacitor and the anode of the second voltage zener diode is connected to the non-inverting input terminal, the inverting input terminal and the negative power supply terminal of the second operational amplifier respectively; The positive power supply terminal of the second operational amplifier is connected to a power supply and a first terminal of the second capacitor respectively, and the second terminal of the second capacitor is grounded; A parallel node of the second end of the first capacitor and the anode of the second voltage stabilizing diode, a non-inverting input terminal, an inverting input terminal and a negative power supply terminal of the second operational amplifier are all grounded.

9. A reclosing device, characterized in that: The device comprises the leakage detection circuit according to any one of claims 1 to 8.

10. A circuit breaker, characterized in that: Comprising the reclosing device as claimed in claim 9.

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