Detection circuit, detection method and circuit breaker

Abstract

The present application provides a detection circuit, a detection method and a circuit breaker, which relate to the field of circuits, and solve the problem that the current circuit breaker can only be used for functional self-detection in a single-phase AC circuit. The present application includes a leakage detection module, which includes a control unit, a residual current mutual inductance core, and a residual current acquisition coil, a residual current test coil and an abnormal feedback unit electrically connected to the control unit. The present application also includes a power supply module, which is used to convert the high-voltage power supply signal input by the target line into a low-voltage power supply signal, and provide the low-voltage power supply signal to the residual current test coil. The power supply input for the simulated leakage detection in the present application is a low-voltage power supply signal converted by the power supply module, so the leakage self-detection function is no longer limited by the negative half-cycle self-detection of the single-phase power supply, and can be generally used in AC and DC systems, with strong flexibility.

Description

Technical Field

[0001] The present application relates to the field of circuit technology, and in particular to a detection circuit, a detection method and a circuit breaker. Background Art

[0002] Currently, the residual current operated circuit breakers with circuit self-test function on the market are mainly implemented using dedicated chips, and mainly use the negative half cycle of sinusoidal alternating current to realize the self-test function. This solution has the disadvantages of being only applicable to single-phase AC circuits and having poor flexibility. Summary of the invention

[0003] The present application provides a detection circuit, a detection method and a circuit breaker that can detect leakage in a target circuit and can perform self-detection on a detection circuit having the function of a leakage protection circuit, and can be used in AC and DC circuits, thereby solving the problem that current circuit breakers can only be used for functional self-detection in single-phase AC circuits.

[0004] In one aspect, the present application provides a detection circuit, comprising:

[0005] A leakage detection module, the leakage detection module comprising a control unit, a residual current mutual inductance core, and a residual current acquisition coil, a residual current test coil and an abnormal feedback unit electrically connected to the control unit, the residual current mutual inductance core is sleeved outside the target line to be detected for leakage, and the residual current acquisition coil and the residual current test coil are both wound on the residual current mutual inductance core;

[0006] A power module, comprising a power input terminal and a power output terminal, wherein the power input terminal is electrically connected to a target circuit for leakage detection, and the power output terminal is electrically connected to the control unit and the residual current test coil, and the power module is used to convert a high-voltage power signal input by the target circuit into a low-voltage power signal, and provide the low-voltage power signal to the residual current test coil;

[0007] Among them, the control unit controls the residual current test coil to generate a simulated residual current to simulate leakage in the target line. At the same time, the control unit obtains fault information of the leakage detection function by detecting the abnormal feedback signal fed back by the abnormal feedback unit.

[0008] In a possible implementation of the present application, the detection circuit further includes a switch module electrically connected to the leakage detection module, and the switch module is used to control the on and off of the target line.

[0009] In a possible implementation of the present application, the switch module includes a trip switch, which is disposed in the target line and is used to control the on / off state of the target line.

[0010] In a possible implementation of the present application, the switch module includes a trip control unit electrically connected between the trip switch and the control unit, and the trip control unit includes:

[0011] A first switch tube, wherein a control electrode of the first switch tube is electrically connected to a pin of the control unit, and a first end of the first switch tube is electrically connected to a first node;

[0012] a second switch tube, wherein a control electrode of the second switch tube is electrically connected to a pin of the control unit, a first end of the second switch tube is grounded, and a second end of the second switch tube is electrically connected to the first node;

[0013] A trip coil, wherein a first end of the trip coil is electrically connected to a second end of the first switch tube, and a second end of the trip coil is electrically connected to the trip switch and the power module.

[0014] In a possible implementation of the present application, the abnormality feedback unit includes:

[0015] A fourth switch tube, wherein a control electrode and a second end of the fourth switch tube are electrically connected to two pins of the control unit respectively, and a first end of the fourth switch tube is grounded;

[0016] A second node, wherein the second node is an electrical connection point between a control electrode of the fourth switch tube and a pin of the control unit, and another pin of the control unit is electrically connected to the second node.

[0017] In a possible implementation of the present application, the second switch tube in the trip control unit and the fourth switch tube in the abnormal feedback unit are the same switch tube.

[0018] In a possible implementation of the present application, the leakage detection module also includes a residual current acquisition unit, which includes a signal input end and two signal output ends, the signal input end is electrically connected to the residual current acquisition coil, and the two signal output ends are respectively electrically connected to a pin of the control unit and the abnormal feedback unit, and the residual current acquisition unit is used to detect the current value in the residual current acquisition coil and send a leakage detection signal to the control unit and / or the abnormal feedback unit.

[0019] In a possible implementation of the present application, the leakage detection module also includes a residual current testing unit, and the residual current testing unit includes a test switch tube, the gate of the test switch tube is electrically connected to a pin of the control unit, the drain of the test switch tube is electrically connected to an input end of the residual current test coil, the source of the test switch tube is grounded, and the test switch tube is used to control the power supply to the residual current test coil.

[0020] In a possible implementation of the present application, the leakage detection module further includes a button trigger module, and the button trigger module includes a test button electrically connected to the control unit, and when the test button is pressed, a trigger signal is provided to the control unit.

[0021] In a possible implementation of the present application, the self-test circuit also includes an indication module, which is electrically connected to a pin of the control unit. When the control unit detects that the leakage detection module fails, the control unit controls the indication module to send a fault prompt signal.

[0022] On the other hand, the present application provides a detection method, which is applied to a detection circuit, wherein the detection circuit includes a power module and a leakage detection module electrically connected to the power module, wherein the leakage detection module includes a control unit, a residual current mutual inductance core, and a residual current acquisition coil electrically connected to the control unit, a residual current test coil, a residual current acquisition unit, and an abnormal feedback unit, wherein the detection method includes:

[0023] The control unit controls the residual current test coil to generate a simulated residual current to simulate leakage in the target circuit for detecting leakage;

[0024] The control unit obtains fault condition information of the leakage detection function by detecting the abnormal feedback signal fed back by the abnormal feedback unit.

[0025] In a possible implementation of the present application, the detection circuit further includes a switch module, and the switch module is used to control the on / off of the target line. Before the control unit controls the residual current test coil to generate a simulated residual current, the method further includes:

[0026] Obtaining a stop signal of the switch module;

[0027] According to the stop signal, the control unit controls the switch module to stop operating.

[0028] In a possible implementation of the present application, before obtaining the stop signal of the switch module, the method further includes:

[0029] Get the delay duration;

[0030] Compare the delay duration with a preset duration threshold to obtain a duration comparison result;

[0031] When the duration comparison result is that the delay duration is less than or equal to the duration threshold, a start signal is obtained, and the start signal instructs the control unit to control the switch module to start operation;

[0032] When the duration comparison result is that the delay duration is greater than the duration threshold, a stop signal is obtained, and the stop signal instructs the control unit to control the switch module to stop operating.

[0033] In a possible implementation of the present application, the detection circuit further includes a test switch tube, the gate of the test switch tube is electrically connected to a pin of the control unit, the drain of the test switch tube is electrically connected to an input end of the residual current test coil, and the control unit controls the residual current test coil to generate a simulated residual current, including:

[0034] A pin of the control unit outputs a pulse width modulation wave;

[0035] The test switch tube controls the on and off of the residual current test coil according to the pulse width modulation wave;

[0036] When the residual current test coil is energized, the residual current test coil generates a simulated residual current on the residual current mutual inductance core.

[0037] In a possible implementation of the present application, before the control unit obtains the fault condition information of the leakage detection function by detecting the abnormal feedback signal fed back by the abnormal feedback unit, the method further includes:

[0038] The residual current acquisition unit receives the current input by the residual current acquisition coil, and outputs a current acquisition signal to the control unit;

[0039] The control unit outputs a first leakage detection signal to the abnormality feedback unit according to the current acquisition signal;

[0040] The abnormal feedback unit generates the abnormal feedback signal according to the first leakage detection.

[0041] or:

[0042] The residual current acquisition unit receives the current input by the residual current acquisition coil, and outputs a second leakage detection signal to the abnormality feedback unit;

[0043] The abnormal feedback unit generates the abnormal feedback signal according to the second leakage detection.

[0044] In a possible implementation of the present application, the leakage detection module further includes a test button, and the control unit controls the residual current test coil to generate a simulated residual current, including:

[0045] When the duration comparison result is that the delay duration is less than or equal to the duration threshold, the control unit controls the switch module to start operation, and the control unit detects the manual detection trigger signal sent by the test button;

[0046] According to the manual detection trigger signal, the control unit controls the residual current test coil to generate a simulated residual current.

[0047] On the other hand, the present application also provides a circuit breaker, which adopts the detection circuit as described above and / or adopts the detection method as described above.

[0048] In the present application, the control unit controls the residual current test coil to generate a simulated residual current on the residual current mutual inductance core to simulate leakage in the target line, and the simulated leakage current is collected by the residual current collection coil. The control unit detects the simulated leakage current to perform a simulated leakage detection, and the result of the simulated leakage detection is obtained by the abnormal feedback signal fed back by the abnormal feedback unit, and then the fault condition information of the leakage detection function is obtained, that is, if the abnormal feedback signal fed back by the abnormal feedback unit is a successful simulated leakage detection, then the fault condition information is that the leakage detection function is normal; if the abnormal feedback signal fed back by the abnormal feedback unit is a failed simulated leakage detection, then the fault condition information is that the leakage detection function is abnormal. Since the power input for the simulated leakage detection in the present application is a low-voltage power supply signal converted by a power module, the leakage self-detection function is no longer limited by the negative half-cycle self-detection of a single-phase power supply, and can be widely used in AC and DC systems, with strong flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0050] Figure 1 is a structural schematic diagram of a self-test circuit in an embodiment of the present application;

[0051] Figure 2 is a structural schematic diagram of a residual current collection unit in an embodiment of the present application;

[0052] Figure 3 It is a flowchart of the self-test method in the embodiment of the present application. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0054] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0055] In this application, the word "exemplary" is used to mean "serving as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is given to enable any person skilled in the art to implement and use the present invention. In the following description, details are listed for the purpose of explanation. It should be understood that one of ordinary skill in the art can recognize that the present invention can be implemented without using these specific details. In other examples, well-known structures and processes will not be elaborated in detail to avoid obscuring the description of the present invention with unnecessary details. Therefore, the present invention is not intended to be limited to the embodiments shown, but is consistent with the widest scope consistent with the principles and features disclosed in this application.

[0056] The embodiments of the present application provide a detection circuit, a detection method and a circuit breaker, which are described in detail below.

[0057] like Figure 1 FIG. 1 is a schematic diagram of a structure of a detection circuit in an embodiment of the present application, and the detection circuit includes:

[0058] A leakage detection module, the leakage detection module includes a control unit 110, a residual current mutual inductance core 101, and a residual current collection coil 107, a residual current test coil 108 and an abnormal feedback unit 113 electrically connected to the control unit 110. The residual current mutual inductance core 101 is sleeved outside the target line 111 to be detected for leakage, and the residual current collection coil 107 and the residual current test coil 108 are both wound on the residual current mutual inductance core 101;

[0059] The power module 102 includes a power input terminal and a power output terminal, wherein the power input terminal is electrically connected to the target line 111 for leakage detection, and the power output terminal is electrically connected to the control unit 110 and the residual current test coil 108. The power module 102 is used to convert the high-voltage power signal input from the target line 111 into a low-voltage power signal, and provide the low-voltage power signal to the residual current test coil 108;

[0060] The control unit 110 controls the residual current test coil 108 to generate a simulated residual current to simulate leakage in the target line 111 . At the same time, the control unit 110 obtains fault information of the leakage detection function by detecting the abnormal feedback signal fed back by the abnormal feedback unit 113 .

[0061] In the present application, the control unit 110 controls the residual current test coil 108 to generate a simulated residual current on the residual current mutual inductance core 101 to simulate leakage in the target line 111, and the simulated leakage current is collected by the residual current collection coil 107. The control unit 110 detects the simulated leakage current to perform a simulated leakage detection, and obtains the result of the simulated leakage detection through the abnormal feedback signal fed back by the abnormal feedback unit 113, and then obtains the fault condition information of the leakage detection function, that is, if the abnormal feedback signal fed back by the abnormal feedback unit 113 is a successful simulated leakage detection, then the fault condition information is that the leakage detection function is normal, if the abnormal feedback signal fed back by the abnormal feedback unit 113 is a failed simulated leakage detection, then the fault condition information is that the leakage detection function is abnormal. Since the power input for the simulated leakage detection in the present application is a low-voltage power supply signal converted by the power module 102, the leakage self-detection function is no longer limited by the negative half-cycle self-detection of the single-phase power supply, and can be generally used in AC and DC systems, with strong flexibility.

[0062] In this embodiment, the power supply module 102 can adopt a switching power supply or a linear power supply, which is not specifically limited here. The power input end of the power supply module 102 has four input ends, and the four input ends correspond to four power lines electrically connected to the AC power supply (C, B, A, N). The power output end of the power supply module 102 includes three output ends, and the three output ends are respectively electrically connected to the first end of the residual current test coil 108, the control unit 110 and the second end of the tripping coil (see below). The residual current test coil 108, the control unit 110 and the tripping coil are powered by the power supply module 102.

[0063] In this embodiment, the control unit 110 may be any one of a central processing unit (CPU), an electronic control unit 110 (ECU), a microcontroller unit 110110 (MCU), a memory protection module (MPU), and an integrated circuit chip (System on a Chip, SOC). It is understood that in other embodiments, the control unit 110 may also be other control units 110 that meet the circuit requirements, and the regulation of the control unit 110 in this embodiment is not specifically limited.

[0064] In this embodiment, the residual current acquisition coil 107 and the residual current test coil 108 are jointly connected to the secondary of the residual current mutual inductance core 101, wherein the residual current acquisition coil 107 is used to sense the change of the residual current in the target line 111, and use the sensed residual current value as the input of the residual current acquisition unit 105 (as shown below), and the residual current test coil 108 is used to generate a simulated residual current for checking whether the leakage detection function of the residual detection circuit is normal, that is, the residual current acquisition coil 107 with the leakage detection function and the residual current test coil 108 with the circuit self-test function share the same residual current mutual inductance core 101, making the circuit simpler and more practical.

[0065] In another embodiment of the present application, the detection circuit further includes a switch module 104 electrically connected to the leakage detection module, and the switch module 104 is used to control the on-off of the target line 111 .

[0066] The switch module 104 includes a trip switch, which is disposed in the target line 111. The trip switch is electrically connected between the AC power supply (C, B, A, N) and the external device and is located on the AC power supply side. The trip switch is used to control the on and off of the target line 111. Under normal circumstances, the trip switch remains in a closed state. Once an excessively high leakage current is detected in the target line 111, the trip switch is controlled to be disconnected to achieve the leakage protection function of the target line 111 and the external device.

[0067] The switch module 104 includes a trip control unit 112 electrically connected between the trip switch and the control unit 110. The trip control unit 112 is used to control the opening and closing of the trip switch. The trip control unit 112 includes:

[0068] A first switch tube Q1, wherein a gate of the first switch tube Q1 is electrically connected to a pin IO1 of the control unit 110, and a source of the first switch tube Q1 is electrically connected to a first node N1;

[0069] A second switch tube Q2, wherein a gate of the second switch tube Q2 is electrically connected to the pin IO4 of the control unit 110, a source of the second switch tube Q2 is grounded, and a drain of the second switch tube Q2 is electrically connected to the first node N1;

[0070] A trip coil, a first end of the trip coil is electrically connected to the drain of the first switch tube Q1 , and a second end of the trip coil is electrically connected to the trip switch and the power module 102 .

[0071] The first switch tube Q1 and the second switch tube Q2 may be MOS tubes or triodes, and the second switch tube Q2 may also be a thyristor element. In this embodiment, there is no specific limitation on the specifications of the first switch tube Q1 and the second switch tube Q2.

[0072] In this embodiment, when leakage current detection is performed on the target line 111, the pin IO1 of the control unit 110 is maintained at a high level, so that the first switch tube Q1 remains in a conducting state. When it is detected that there is residual current in the target line 111 and the residual current is higher than the preset threshold current, the fourth pin IO4 of the control unit 110 or the residual current acquisition unit 105 (as shown below) outputs a high level, so that the second switch tube Q2 is turned on, and then the trip coil is energized, the trip switch is turned on, and the target line 111 is disconnected. When there is residual current in the target line 111, the target line 111 is controlled to be disconnected through the switch module 104, thereby achieving the effect of protecting the circuit.

[0073] In another embodiment of the present application, the abnormal feedback unit 113 includes a third switch tube and a second node N2.

[0074] The fourth switch tube Q4, the gate and the drain of the fourth switch tube Q4 are electrically connected to the two pins of the control unit 110 respectively, and the source of the fourth switch tube Q4 is grounded. In this embodiment, the second switch tube Q2 in the trip control unit 112 and the fourth switch tube Q4 in the abnormal feedback unit 113 are the same switch tube, that is, the gate of the fourth switch tube Q4 is electrically connected to the pin IO2 of the control unit 110, and the drain of the fourth switch tube Q4 is electrically connected to the pin IO4 of the control unit 110.

[0075] The second node N2 is an electrical connection point between the gate of the fourth switch tube Q4 and the pin IO2 of the control unit 110. The pin IO3 of the control unit 110 is electrically connected to the second node N2. In this embodiment, the level change of the second node N2 is the abnormal feedback signal fed back to the control unit 110 by the abnormal feedback unit 113.

[0076] Since the detection circuit in this application has the following two functions:

[0077] (1) A function of performing leakage detection on the target line 111;

[0078] (2) The function of self-checking the leakage detection function of the detection circuit itself;

[0079] Furthermore, since during the self-check of the leakage detection function of the detection circuit itself, if the switch module 104 keeps running, the control unit 110 can easily output a control signal to the trip control unit 112 when detecting the simulated leakage current, thereby controlling the trip switch to trip and disconnect the target line 111. Therefore, when performing the self-check of the circuit leakage function, the switch module 104 needs to be stopped to avoid the situation where the target line 111 is frequently disconnected due to the circuit self-check.

[0080] Therefore, in the specific application process of the circuit leakage function self-test, the pin IO1 of the control unit 110 is kept at a low level, so that the first switch tube Q1 remains in a disconnected state. At the same time, the pin IO2 of the control unit 110 continues to output a high level, and the control unit 110 controls the residual current test coil 108 to generate a simulated residual current on the residual current mutual inductance core 101. When the control unit 110 detects that the simulated residual current is higher than the preset threshold current, the pin IO4 of the control unit 110 changes to a high level, the second switch tube Q2 is turned on, and the voltage at the second node N2 is pulled low. At this time, the pin IO3 port of the control unit 110 detects that the voltage at the second node N2 is The high level is pulled to a low level, that is, the abnormal feedback signal fed back by the abnormal feedback unit 113 is that the high level at the second node N2 is pulled to a low level, indicating that the simulated leakage detection is successful and the self-test is successful, then the corresponding fault condition information is that the leakage detection function is normal. If the pin IO4 of the control unit 110 changes to a high level, the second switch tube Q2 is not turned on, or the pin IO3 port of the control unit 110 detects that the high level at the second node N2 is not pulled low, that is, the abnormal feedback signal fed back by the abnormal feedback unit 113 is that the second node N2 is still at a high level, indicating that the simulated leakage detection fails and the self-test fails, then it means that the leakage detection function of the detection circuit is abnormal.

[0081] In another embodiment of the present application, the leakage detection module further includes a residual current acquisition unit 105, which is electrically connected between the pin ADC of the control unit 110 and the residual current acquisition coil 107. The residual current acquisition unit 105 includes a signal input terminal and two signal output terminals. The signal input terminal of the residual current acquisition unit 105 is electrically connected to the residual current acquisition coil 107, one signal output terminal of the residual current acquisition unit 105 is electrically connected to the pin ADC of the control unit 110, and the other signal output terminal of the residual current acquisition unit 105 is electrically connected to the gate of the fourth switch tube Q4 in the abnormal feedback unit 113. The residual current acquisition unit 105 is used to detect the current value in the residual current acquisition coil 107 and send a leakage detection signal to the control unit 110 and / or the abnormal feedback unit 113.

[0082] Specifically, the residual current acquisition unit 105 is used to process the current changes induced in the residual current acquisition coil 107. The induced residual current value can be used as the input of the pin ADC of the control unit 110, or the current changes induced in the residual current acquisition coil 107 can be processed separately. During the leakage detection of the target line 111 or the self-test of the leakage detection function of the detection circuit, when the residual current value input by the residual current acquisition coil 107 exceeds the set threshold, the control unit 110 or the residual current acquisition unit 105 can control the second switch tube Q2 (fourth switch tube Q4) to turn on.

[0083] The residual current acquisition unit 105 may be a processing circuit composed of an operational amplifier, or may be a circuit composed of a dedicated residual current acquisition chip. In this embodiment, Figure 2 As shown, the residual current acquisition unit 105 includes an operational amplifier IC1-1, a capacitor C1, a capacitor C2, a resistor R2 and a resistor R3, the same-direction input terminal of the operational amplifier IC1-1 is electrically connected to the first end of the residual current acquisition coil 107, the reverse input terminal of the operational amplifier IC1-1 is electrically connected to the second end of the residual current acquisition coil 107, one end of the resistor R2 and one end of the capacitor C2 are electrically connected together, the other end of the resistor R2 and the other end of the capacitor C2 are electrically connected to the same-direction input terminal of the operational amplifier IC1-1 at the same time, the two ends of the capacitor C1 are electrically connected to the reverse input terminal of the operational amplifier IC1-1 and the output terminal of the operational amplifier IC1-1 respectively, and the resistor R3 is electrically connected to the capacitor C1 in parallel. The residual current signal input to the operational amplifier IC1-1 is amplified by the operational amplifier IC1-1 and then input to the pin ADC of the control unit 110, and the residual current signal is detected by the control unit 110.

[0084] Among them, the operational amplifier IC1-1 is an operational amplifier integrated chip. In this embodiment, the operational amplifier integrated chip can be a precision bipolar input stage operational amplifier of the OP07 series or OP27 series, or can be other types of bipolar operational amplifiers, which are not limited here. In addition, the residual current acquisition unit 105 can also be a circuit composed of a dedicated residual current acquisition chip, such as VG54123, FM2147, FM2149, etc.

[0085] In another embodiment of the present application, Figure 1As shown, the leakage detection module also includes a residual current test unit 103, and the residual current test unit 103 includes a test switch tube Q3, the gate of the test switch tube Q3 is electrically connected to the pin IO7 of the control unit 110, the drain of the test switch tube Q3 is electrically connected to the second end of the residual current test coil 108, and the source of the test switch tube Q3 is grounded. The test switch tube Q3 is used to control the residual current test coil 108 to be energized. Among them, the test switch tube Q3 can be a MOS tube or a triode, and the specifications of the test switch tube Q3 are not specifically limited in this embodiment.

[0086] In this embodiment, the test switch tube Q3 is usually used to control the residual current test coil 108 to be energized when performing a circuit leakage function self-test. Therefore, in a specific application process, it is necessary to control the switch module 104 to be disconnected, that is, the pin IO1 of the control unit 110 is kept at a low level, so that the first switch tube Q1 remains in a disconnected state. At the same time, the pin IO7 of the control unit 110 continuously outputs a pulse width modulation wave value, and the test switch tube Q3 controls the residual current test coil 108 to be turned on and off according to the pulse width modulation wave.

[0087] In another embodiment of the present application, the leakage detection module further includes a button trigger module 109, which includes a test button K1 electrically connected to the control unit. When the test button K1 is pressed, it provides a trigger signal to the control unit.

[0088] Specifically, the button trigger module 109 includes a test button K1 and a first resistor R1, the first pole of the test button K1 is electrically connected to pin IO6 of the control unit 110, the second pole of the test button K1 is grounded, the first end of the first resistor R1 is electrically connected to the power supply Vdd, and the second end is electrically connected to the electrical connection point between the first pole of the test button K1 and the control unit 110. When the detection circuit is in a state of performing leakage current detection on the target line 111, the test button K1 is convenient for the user to manually trigger the detection circuit to perform self-test of the leakage detection function. In the specific application process, the pin IO1 of the control unit 110 is kept at a high level, so that the first switch tube Q1 remains in a conducting state. The user presses the test button K1, and the control unit 110 detects that the test button K1 is pressed. The pin IO7 of the control unit 110 outputs a pulse width modulation wave. When the residual current test coil 108 is turned on, the power output end of the power module 102 outputs a low-voltage power signal to the residual current test coil 108, thereby simulating the leakage current. If the trip control unit 112 controls the trip switch to be disconnected, the leakage detection function of the detection circuit is normal. If the trip switch has no response, the leakage detection function of the detection circuit is abnormal.

[0089] In another embodiment of the present application, the self-test circuit further includes an indication module 106, and the indication module 106 is electrically connected to the pin IO5 of the control unit 110. When the control unit 110 detects that the leakage detection module fails, the control unit 110 controls the indication module 106 to send a fault prompt signal. When the detection circuit self-test fails or the detection circuit detects that the target line 111 has residual current leakage, the indication module 106 sends a fault prompt signal. The indication module 106 sends the fault prompt signal in a manner that can be a local sound and light indication, or can be an indication alarm through a remote communication method. In addition, in this embodiment, the indication module 106 can also indicate the operating status of the self-test circuit.

[0090] In another embodiment of the present application, in order to better apply the detection circuit, the present application provides a detection method, which is applied to the above-mentioned detection circuit of the present application. The detection method includes:

[0091] The control unit 110 controls the residual current test coil 108 to generate a simulated residual current to simulate leakage in the target line 111 to be tested for leakage.

[0092] The control unit 110 obtains the fault condition information of the leakage detection function by detecting the abnormal feedback signal fed back by the abnormal feedback unit 113 .

[0093] In this embodiment, a time period is preset in the control unit 110 , and the leakage detection function of the detection circuit is tested once within the preset time period. The time period can be set manually or by default in the control unit 110 .

[0094] The control unit 110 controls the residual current test coil 108 to generate a simulated residual current, including:

[0095] In a preset time period, the pin IO7 of the control unit 110 outputs a pulse width modulation wave;

[0096] The test switch tube Q3 controls the on and off of the residual current test coil 108 according to the pulse width modulation wave;

[0097] When the residual current test coil 108 is energized, the residual current test coil 108 generates a simulated residual current on the residual current mutual inductance core 101 .

[0098] That is, when the residual current test coil 108 is turned on, the power output terminal of the power module 102 outputs a low-voltage power signal to the residual current test coil 108 , thereby simulating leakage of the target circuit 111 .

[0099] The control unit 110 obtains fault information of the leakage detection function by detecting the abnormal feedback signal fed back by the abnormal feedback unit 113, including:

[0100] When the abnormal feedback signal detected by the control unit 110 is that the high level at the second node N2 is pulled to a low level, it means that the simulated leakage detection is successful and the self-test is successful, then the corresponding fault condition information is that the leakage detection function is normal;

[0101] When the abnormal feedback signal detected by the control unit 110 is that the second node N2 is still at a high level, it means that the simulated leakage detection fails, the self-test fails, and the leakage detection function of the detection circuit is abnormal.

[0102] In another embodiment of the present application, as mentioned above, when performing a circuit leakage function self-test, the switch module 104 needs to be stopped to avoid frequent disconnection of the target line 111 due to the circuit self-test.

[0103] Therefore, before the control unit 110 controls the residual current test coil 108 to generate a simulated residual current, the method further includes:

[0104] Obtaining a stop signal from the switch module 104;

[0105] According to the stop signal, the control unit 110 controls the switch module 104 to stop operating.

[0106] In this embodiment, when the detection circuit itself is preparing to perform a self-test operation of the leakage detection function, the control unit 110 generates a stop signal for the switch module 104, and according to the stop signal, the control unit 110 controls the switch module 104 to stop running, that is, the pin IO1 of the control unit 110 outputs a low level, and the first switch tube Q1 remains in the disconnected state.

[0107] In another embodiment of the present application, in order to realize the two functions of the detection circuit being performed asynchronously, that is, the function of leakage detection on the target circuit 111 and the function of self-checking the leakage detection function of the detection circuit itself are performed asynchronously, in the present application, the operation of leakage detection on the target circuit 111 and the operation of self-checking the leakage detection function of the detection circuit itself are set to be performed in different time periods respectively.

[0108] Therefore, before obtaining the stop signal of the switch module 104, the method further includes:

[0109] Get the delay duration t;

[0110] When the target line 111 is powered on or the detection circuit is powered on, the control unit 110 starts the delay and forms a delay time t after the start-up accordingly.

[0111] Compare the delay time t with the preset time threshold to obtain a time comparison result;

[0112] In this embodiment, the duration comparison result includes the duration comparison result that the delay duration t is less than or equal to the duration threshold and the duration comparison result that the delay duration t is greater than the duration threshold, wherein the duration threshold can be pre-set in the control unit 110 before the detection circuit starts running, or it can be the default setting of the control unit 110 when leaving the factory.

[0113] When the time comparison result is that the delay time t is less than or equal to the time threshold, a start signal is obtained, and the start signal instructs the control unit 110 to control the switch module 104 to start operation;

[0114] Specifically, when the duration comparison result is that the delay duration t is less than or equal to the duration threshold, the start signal is a high-level signal output by pin IO1 of the control unit 110. When pin IO1 of the control unit 110 outputs a high level, the first switch tube Q1 remains in the on state, the switch module 104 starts running, and the residual current in the target line 111 is detected through the detection circuit.

[0115] When the time comparison result is that the delay time t is greater than the time threshold, a stop signal is obtained, and the stop signal instructs the control unit 110 to control the switch module 104 to stop running;

[0116] Specifically, when the duration comparison result is that the delay duration t is greater than the duration threshold, the stop signal is a low-level signal output by pin IO1 of the control unit 110. When pin IO1 of the control unit 110 outputs a low level, the first switch tube Q1 remains in the off state, the switch module 104 stops running, and the detection circuit performs a self-test of the leakage detection function within a set time period through the detection circuit.

[0117] In this embodiment, when the target line 111 is powered on or when the detection circuit is powered on, the control unit 110 starts the delay. When the delay time t does not exceed the preset time threshold, the detection circuit detects the residual current in the target line 111. When the delay time t exceeds the preset time threshold, the detection circuit performs a self-test of the leakage detection function of the detection circuit within a set time period, thereby achieving the purpose of performing the two operations of the detection circuit independently in two time periods.

[0118] In another embodiment of the present application, before the control unit 110 obtains the fault condition information of the leakage detection function by detecting the abnormal feedback signal fed back by the abnormal feedback unit 113, the method further includes:

[0119] The residual current acquisition unit 105 receives the current input by the residual current acquisition coil 107 and outputs a current acquisition signal to the control unit 110;

[0120] The control unit 110 outputs a first leakage detection signal to the abnormality feedback unit 113 according to the current acquisition signal;

[0121] The abnormal feedback unit 113 generates an abnormal feedback signal according to the first leakage detection.

[0122] In this embodiment, the residual current acquisition unit 105 is used to collect and process the residual current induced in the residual current acquisition coil 107, and output the processed current value to the pin ADC of the control unit 110, and the control unit 110 determines whether the residual current exceeds the set residual current threshold.

[0123] The first leakage detection signal output by the control unit 110 is a signal output by the pin IO4 of the control unit 110. The first leakage detection signal is used to control the on and off of the fourth switch tube Q4. The first leakage detection signal includes a high level signal and a low level signal. When the residual current exceeds the set residual current threshold, the first leakage detection signal is a high level. When the residual current does not exceed the set residual current threshold, the first leakage detection signal is a low level.

[0124] When the first leakage detection signal is a high level signal, the fourth switch tube Q4 in the abnormal feedback unit 113 is turned on, and the abnormal feedback signal fed back at the second node N2 is that the high level at the second node N2 is pulled to a low level;

[0125] When the first leakage detection signal is a low level signal, the fourth switch tube Q4 in the abnormal feedback unit 113 is turned off, and the abnormal feedback signal fed back at the second node N2 is still at a high level.

[0126] In another embodiment of the present application, before the control unit 110 obtains the fault condition information of the leakage detection function by detecting the abnormal feedback signal fed back by the abnormal feedback unit 113, the method further includes:

[0127] The residual current acquisition unit 105 receives the current input by the residual current acquisition coil 107 and outputs a second leakage detection signal to the abnormality feedback unit 113;

[0128] The abnormality feedback unit 113 generates an abnormality feedback signal according to the second leakage detection.

[0129] In this embodiment, the residual current acquisition unit 105 is used to collect and process the residual current induced in the residual current acquisition coil 107 and to determine whether the residual current exceeds a set residual current threshold, and output a second leakage detection signal to the abnormal feedback unit 113 according to the judgment structure.

[0130] The second leakage detection signal is used to control the on and off of the fourth switch tube Q4. The second leakage detection signal includes a high level signal and a low level signal. When the residual current exceeds the set residual current threshold, the second leakage detection signal is at a high level. When the residual current does not exceed the set residual current threshold, the second leakage detection signal is at a low level.

[0131] When the second leakage detection signal is a high level signal, the fourth switch tube Q4 in the abnormal feedback unit 113 is turned on, and the abnormal feedback signal fed back at the second node N2 is that the high level at the second node N2 is pulled to a low level;

[0132] When the second leakage detection signal is a low level signal, the fourth switch tube Q4 in the abnormal feedback unit 113 is turned off, and the abnormal feedback signal fed back at the second node N2 is still at a high level.

[0133] In another embodiment of the present application, in order to achieve the purpose of detecting the leakage detection function of the detection circuit while the detection circuit performs leakage detection on the target line 111, the control unit 110 controls the residual current test coil 108 to generate a simulated residual current, which may also include:

[0134] When the delay time is less than or equal to the time threshold, the control unit 110 controls the switch module 104 to start operation.

[0135] The control unit 110 detects a manual detection trigger signal sent by the test button K1;

[0136] According to the manual detection trigger signal, the control unit 110 controls the residual current test coil 108 to generate a simulated residual current.

[0137] In this embodiment, when the test button K1 is pressed and the pin IO6 of the control unit 110 detects the manual detection trigger signal, the pin IO7 of the control unit 110 outputs a pulse width modulation wave. When the residual current test coil 108 is turned on, the power output end of the power module 102 outputs a low-voltage power signal to the residual current test coil 108, thereby simulating a leakage current. At this time, the control unit 110 detects the simulated leakage current. If the trip control unit 112 controls the trip switch to be disconnected, the leakage detection function of the detection circuit is normal. If the trip switch does not respond, the leakage detection function of the detection circuit is abnormal.

[0138] Since the self-test mode of the leakage detection function of the detection circuit is performed by manually triggering the test button K1, the problem of frequent tripping of the trip switch can be avoided artificially.

[0139] In order to facilitate further understanding of the scheme, Figure 2 and Figure 3 As shown, the technical solution of the present application is described as a whole in combination with the detection circuit and the detection method in the present application.

[0140] When the target line 111 is powered on or the detection circuit is powered on, the pin IO1 of the control unit 110 outputs a high level and starts a delay, forming a delay time t;

[0141] During the delay time t, the first switch tube Q1 is turned on, and the pin IO6 of the control unit 110 detects whether the test button K1 is pressed. At the same time, the control unit 110 detects whether the residual current value in the target circuit 111 exceeds the threshold value. If it is detected that the test button K1 is pressed or the residual current value of the main circuit exceeds the threshold value, the control unit 110 outputs a high level through IO4 to control the switch module 104 to power on, triggering the trip switch to turn on, so that the target circuit is tripped;

[0142] If the control unit 110 does not detect whether the test button K1 is pressed or whether the residual current value in the target line 111 exceeds the threshold, it determines whether the delay time t exceeds the set time threshold;

[0143] If the delay time t exceeds the set threshold, the pin IO1 of the control unit 110 outputs a low level, thereby disconnecting the switch module 104, and the target line 111 will not trip;

[0144] At the same time, the pin IO2 of the control unit 110 outputs a high level, and the pin IO7 of the control unit 110 outputs a pulse width modulation wave (PWM wave) to intermittently turn on the third switch tube Q3. After the third switch tube Q3 is turned on, simulated leakage is generated in the residual current test coil 108. At this time, the pin IO4 of the control unit 110 or the residual current acquisition and processing circuit outputs a high level to turn on the fourth switch tube Q4. The pin IO3 of the control unit 110 can detect that the high level output by IO2 is pulled to a low level, and the self-test is successful at this time;

[0145] If the fourth switch tube Q4 is not turned on, the self-test fails, and the indication module 106 may output an alarm.

[0146] In another embodiment of the present application, the present application further provides a circuit breaker, which adopts the detection circuit as described above and / or adopts the detection method as described above.

[0147] The above is a detailed introduction to a detection circuit, a detection method and a circuit breaker provided in the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A detection circuit, characterized in that: include: A leakage detection module, the leakage detection module comprising a control unit, a residual current mutual inductance core, and a residual current acquisition coil, a residual current test coil and an abnormal feedback unit electrically connected to the control unit, the residual current mutual inductance core is sleeved outside the target line to be detected for leakage, and the residual current acquisition coil and the residual current test coil are both wound on the residual current mutual inductance core; A power module, comprising a power input terminal and a power output terminal, wherein the power input terminal is electrically connected to a target circuit for leakage detection, and the power output terminal is electrically connected to the control unit and the residual current test coil, and the power module is used to convert a high-voltage power signal input by the target circuit into a low-voltage power signal, and provide the low-voltage power signal to the residual current test coil; The control unit controls the residual current test coil to generate a simulated residual current to simulate leakage in the target line, and the control unit obtains fault information of the leakage detection function by detecting the abnormal feedback signal fed back by the abnormal feedback unit; The detection circuit further includes a switch module electrically connected to the leakage detection module, and the switch module is used to control the on and off of the target circuit; The switch module includes a trip switch, which is arranged in the target line and used to control the on and off of the target line; The switch module further includes a trip control unit electrically connected between the trip switch and the control unit, and the trip control unit includes: A first switch tube, wherein a control electrode of the first switch tube is electrically connected to a first pin of the control unit, and a first end of the first switch tube is electrically connected to a first node; a second switch tube, wherein a control electrode of the second switch tube is electrically connected to a fourth pin of the control unit, a first end of the second switch tube is grounded, and a second end of the second switch tube is electrically connected to the first node; A trip coil, wherein a first end of the trip coil is electrically connected to a second end of the first switch tube, and a second end of the trip coil is electrically connected to the trip switch and the power module; The abnormal feedback unit comprises: a fourth switch tube, wherein a control electrode and a second end of the fourth switch tube are electrically connected to the second pin and the fourth pin of the control unit respectively, and a first end of the fourth switch tube is grounded; a second node, the second node being an electrical connection point between the second end of the fourth switch tube and the second pin of the control unit, and the third pin of the control unit being electrically connected to the second node; The second switch tube in the trip control unit and the fourth switch tube in the abnormal feedback unit are the same switch tube.

2. The detection circuit according to claim 1, characterized in that: The leakage detection module also includes a residual current acquisition unit, which includes a signal input end and two signal output ends. The signal input end is electrically connected to the residual current acquisition coil, and the two signal output ends are electrically connected to the acquisition pin of the control unit and the abnormal feedback unit respectively. The residual current acquisition unit is used to detect the current value in the residual current acquisition coil and send a leakage detection signal to the control unit and / or the abnormal feedback unit.

3. The detection circuit according to claim 1, characterized in that: The leakage detection module also includes a residual current testing unit, which includes a test switch tube, a gate of the test switch tube being electrically connected to the seventh pin of the control unit, a drain of the test switch tube being electrically connected to an input end of the residual current testing coil, a source of the test switch tube being grounded, and the test switch tube being used to control the power supply to the residual current testing coil.

4. The detection circuit according to claim 3, characterized in that: The leakage detection module also includes a button trigger module, which includes a test button electrically connected to the control unit. When the test button is pressed, a trigger signal is provided to the control unit.

5. The detection circuit according to claim 1, characterized in that: The detection circuit also includes an indication module, which is electrically connected to the fifth pin of the control unit. When the control unit detects that the leakage detection module fails, the control unit controls the indication module to send a fault prompt signal.

6. A detection method, characterized in that: Applied in a detection circuit, the detection circuit includes a power module and a leakage detection module electrically connected to the power module, the leakage detection module includes a control unit, a residual current mutual inductance core, and a residual current acquisition coil, a residual current test coil, a residual current acquisition unit and an abnormal feedback unit electrically connected to the control unit, the detection circuit also includes a switch module electrically connected to the leakage detection module, the switch module includes a trip switch, the trip switch is arranged in a target line, the trip switch is used to control the on and off of the target line, the switch module also includes a trip control unit electrically connected between the trip switch and the control unit, the trip control unit includes a first switch tube, a second switch tube and a trip coil, the control electrode of the first switch tube is electrically connected to the first pin of the control unit, the first end of the first switch tube is electrically connected to a first node, and the first The control electrode of the second switch tube is electrically connected to the fourth pin of the control unit, the first end of the second switch tube is grounded, the second end of the second switch tube is electrically connected to the first node, the first end of the trip coil is electrically connected to the second end of the first switch tube, and the second end of the trip coil is electrically connected to the trip switch and the power module. The abnormal feedback unit includes a fourth switch tube and a second node. The control electrode and the second end of the fourth switch tube are electrically connected to the second pin and the fourth pin of the control unit respectively. The first end of the fourth switch tube is grounded, the second node is the electrical connection point between the second end of the fourth switch tube and the second pin of the control unit, and the third pin of the control unit is electrically connected to the second node. The second switch tube in the trip control unit and the fourth switch tube in the abnormal feedback unit are the same switch tube; the detection method includes: The control unit controls the residual current test coil to generate a simulated residual current to simulate leakage in the target circuit for detecting leakage; The control unit obtains fault condition information of the leakage detection function by detecting the abnormal feedback signal fed back by the abnormal feedback unit.

7. A detection method according to claim 6, characterized in that: Before the control unit controls the residual current test coil to generate a simulated residual current, the method further includes: Obtaining a stop signal of the switch module; According to the stop signal, the control unit controls the switch module to stop operating.

8. A detection method according to claim 7, characterized in that: Before obtaining the stop signal of the switch module, the method further includes: Get the delay duration; Compare the delay duration with a preset duration threshold to obtain a duration comparison result; When the duration comparison result is that the delay duration is less than or equal to the duration threshold, a start signal is obtained, and the start signal instructs the control unit to control the switch module to start operation; When the duration comparison result is that the delay duration is greater than the duration threshold, a stop signal is obtained, and the stop signal instructs the control unit to control the switch module to stop operating.

9. A detection method according to claim 7, characterized in that: The detection circuit further includes a test switch tube, a gate of the test switch tube is electrically connected to the seventh pin of the control unit, a drain of the test switch tube is electrically connected to an input end of the residual current test coil, and the control unit controls the residual current test coil to generate a simulated residual current, including: The seventh pin of the control unit outputs a pulse width modulation wave; The test switch tube controls the on and off of the residual current test coil according to the pulse width modulation wave; When the residual current test coil is energized, the residual current test coil generates a simulated residual current on the residual current mutual inductance core.

10. A detection method according to claim 6, characterized in that: Before the control unit obtains the fault information of the leakage detection function by detecting the abnormal feedback signal fed back by the abnormal feedback unit, the method further includes: the residual current acquisition unit receives the current input by the residual current acquisition coil and outputs the current acquisition signal to the control unit; The control unit outputs a first leakage detection signal to the abnormality feedback unit according to the current acquisition signal; The abnormal feedback unit generates the abnormal feedback signal according to the first leakage detection; or: The residual current acquisition unit receives the current input by the residual current acquisition coil, and outputs a second leakage detection signal to the abnormality feedback unit; The abnormal feedback unit generates the abnormal feedback signal according to the second leakage detection.

11. A detection method according to claim 8, characterized in that: The leakage detection module further includes a test button, and the control unit controls the residual current test coil to generate a simulated residual current, including: When the duration comparison result is that the delay duration is less than or equal to the duration threshold, the control unit controls the switch module to start operation, and the control unit detects the manual detection trigger signal sent by the test button; According to the manual detection trigger signal, the control unit controls the residual current test coil to generate a simulated residual current.

12. A circuit breaker, characterized in that: The circuit breaker adopts the detection circuit as described in any one of claims 1 to 5, and / or adopts the detection method as described in any one of claims 6 to 11.

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