Detection device for circuit breaker and circuit breaker

Abstract

According to the embodiment of the utility model, the invention provides a detection device for a circuit breaker and the circuit breaker. The detection device comprises a micro-control unit which comprises an analog-to-digital conversion port and a digital-to-analog conversion port; the zero-sequence current transformer is coupled in the circuit of the circuit breaker and comprises an induction coil which is wound on the circuit of the circuit breaker; the detection winding is coupled to the induction coil and is connected with the analog-to-digital conversion port of the micro-control unit, so as to induce an induction signal from the induction coil at least during an electric leakage period or an electric leakage detection period, and send an electric leakage signal related to the induction signal to the analog-to-digital conversion port; and the self-checking winding is coupled to the induction coil and is connected with the digital-to-analog conversion port of the micro-control unit so as to receive a self-checking signal sent by the micro-control unit through the digital-to-analog conversion port for electric leakage detection. Therefore, the leakage protection function can be detected under the condition of uninterruptible power supply.

Description

Technical Field

[0001] Example embodiments of the present disclosure generally relate to the field of electrical equipment, and in particular, to a detection device for a circuit breaker and a circuit breaker. Background Art

[0002] A residual current operated protective device is a device used to detect leakage in a circuit and cut off the power supply in time when leakage occurs. It can monitor the leakage current in the circuit and send a signal when the leakage current exceeds the set value, triggering the circuit to cut off the power supply, thereby protecting the safety of personnel and equipment.

[0003] Traditional residual current operated protective devices will cause the circuit breaker to disconnect during self-test, affecting the power consumption of downstream equipment. Utility Model Content

[0004] In a first aspect of the present disclosure, a detection device for a circuit breaker is provided. The detection device includes: a microcontroller unit, including an analog-to-digital conversion port and a digital-to-analog conversion port; and a zero-sequence current transformer, coupled in the circuit of the circuit breaker, and including: an induction coil, wrapped around the circuit of the circuit breaker; a detection winding, coupled to the induction coil and connected to the analog-to-digital conversion port of the microcontroller unit, to induce an induction signal from the induction coil at least during a leakage period or a leakage detection period, and to send a leakage signal related to the induction signal to the analog-to-digital conversion port; and a self-test winding, coupled to the induction coil and connected to the digital-to-analog conversion port of the microcontroller unit, to receive a self-test signal sent by the microcontroller unit via the digital-to-analog conversion port to perform leakage detection.

[0005] In some embodiments, the zero-sequence current transformer further includes: a sampling resistor coupled to the detection winding and adapted to convert the induced signal into a leakage signal.

[0006] In some embodiments, the zero-sequence current transformer further includes: a self-detection resistor coupled to the self-detection winding and adapted to convert the self-detection signal into a self-detection current signal for injection into the induction coil.

[0007] In some embodiments, the detection device further includes a first operational amplifier arranged between the detection winding and the analog-to-digital conversion port.

[0008] In some embodiments, the detection device further includes a second operational amplifier arranged between the self-test winding and the digital-to-analog conversion port.

[0009] In some embodiments, the detection device further comprises an auxiliary power supply coupled to the power supply circuit and adapted to supply power to at least the micro control unit.

[0010] In some embodiments, the detection device further comprises a manual detection button coupled to the microcontroller unit and adapted to be triggered to send a manual detection instruction to the microcontroller unit.

[0011] In some embodiments, the micro control unit further includes: a communication interface, suitable for connecting and communicating with an external device.

[0012] According to the embodiments of the present disclosure, the detection device can manually detect the leakage protection function of the circuit breaker when the user triggers the manual detection button, and can also automatically detect by the microcontroller unit after a predetermined condition is met (for example, a predetermined detection cycle is reached). In the automatic detection process, the load on the circuit breaker can be guaranteed to work normally, thereby improving the convenience of detection.

[0013] In a second aspect of the present disclosure, a circuit breaker is provided. The circuit breaker comprises: a line connected between a power supply circuit and a load; at least one solid-state switch arranged on the line and adapted to control the on-off of the line; a mechanical switch arranged on the line and adapted to control the on-off of the line; and the detection device provided according to the first aspect of the present disclosure, wherein the induction coil of the detection device is arranged between the solid-state switch and the mechanical switch.

[0014] In some embodiments, the solid-state switch comprises a metal-oxide semiconductor field effect transistor.

[0015] In some embodiments, the micro control unit further includes: a first control port coupled to a gate of the metal-oxide semiconductor field effect transistor.

[0016] In some embodiments, the micro control unit further includes: a second control port coupled to the mechanical switch to control the action of the mechanical switch.

[0017] In some embodiments, the circuit breaker further includes at least one pair of voltage detection elements disposed on both sides of at least one solid-state switch to respectively obtain voltage signals on both sides of the solid-state switch.

[0018] In some embodiments, the circuit breaker further includes a pair of sensors, which are respectively arranged on both sides of the solid-state switch and the mechanical switch and are suitable for detecting the current and voltage of the line.

[0019] It should be understood that the contents described in this content section are not intended to limit the key features or important features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements, wherein:

[0021] Figure 1 A simplified schematic diagram of a circuit breaker according to some embodiments of the present disclosure is shown;

[0022] Figure 2 A simplified schematic diagram of a detection device according to some embodiments of the present disclosure is shown; and

[0023] Figure 3 A schematic diagram showing a microcontroller unit controlling the operation of a solid-state switch and a mechanical switch according to some embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0024] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not intended to limit the scope of protection of the present disclosure.

[0025] It should be noted that the titles of any sections / subsections provided herein are not restrictive. Various embodiments are described throughout this article, and any type of embodiment may be included under any section / subsection. In addition, the embodiments described in any section / subsection may be combined in any manner with any other embodiments described in the same section / subsection and / or different sections / subsections.

[0026] In the description of the embodiments of the present disclosure, the term "including" and similar terms should be understood as open inclusion, that is, "including but not limited to". The term "based on" should be understood as "based at least in part on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The term "some embodiments" should be understood as "at least some embodiments". Other explicit and implicit definitions may be included below. The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may be included below.

[0027] As briefly mentioned above, traditional residual current operated protective devices require a button on the panel to trigger ground fault detection. During self-test, the residual current operated protective device disconnects the main circuit to confirm whether a fault has occurred, which will affect downstream electrical equipment. In addition, traditional residual current operated protective devices are unable to determine the cause of the fault.

[0028] According to the detection device for circuit breaker and circuit breaker provided by the present disclosure, the above-mentioned problems and other potential problems existing in the traditional solution are solved or at least partially solved. According to the embodiment of the present disclosure, the detection winding can sense an induction signal through the induction coil when leakage occurs in the circuit, and send a leakage signal related to the induction signal to the analog-to-digital conversion port of the microcontroller unit. After receiving the leakage signal, the microcontroller unit determines that the intensity of the induction signal exceeds the threshold, thereby triggering a tripping operation, and controlling the solid-state switch and the mechanical switch in the circuit breaker to be disconnected in sequence.

[0029] When it is necessary to detect whether the leakage protection function is normal, the microcontroller unit responds to the manual detection instruction issued after the button is triggered or the self-test cycle is satisfied, and sends a self-test signal to the self-test winding through the digital-to-analog conversion port. After receiving the self-test signal, the self-test winding injects a self-test current signal into the induction coil. At this time, the detection winding also coupled to the induction coil senses the induction signal from the induction coil, and sends a leakage signal related to the induction signal to the analog-to-digital conversion port of the microcontroller unit. After receiving the leakage signal, the microcontroller unit determines that the intensity of the induction signal exceeds the threshold and disconnects the solid-state switch.

[0030] The microcontroller unit determines whether the solid-state switch is successfully disconnected based on the voltage signals sent by a pair of voltage detection elements arranged on both sides of the solid-state switch. When it is confirmed that the solid-state switch is disconnected, the microcontroller unit controls the solid-state switch to be turned on again. Since the action time from disconnection to re-conduction of the solid-state switch is very short (for example, 1μs), it can ensure that the electrical equipment is not affected during the circuit breaker self-test.

[0031] Figure 1 FIG. 1 shows a simplified circuit diagram of a circuit breaker according to some embodiments of the present disclosure. Figure 1 As shown, the circuit breaker generally comprises a line arranged between the power supply circuit and the load 9, a mechanical switch 6 and at least one solid-state switch 7 coupled to the line for controlling the on and off of the line, and a detection device arranged between the mechanical switch 6 and the solid-state switch 7. The detection device is suitable for controlling the solid-state switch 7 and the mechanical switch 6 to disconnect successively when leakage occurs in the line, and the detection device is also suitable for detecting the leakage protection function of the circuit breaker.

[0032] Figure 2 FIG. 2 shows a simplified schematic diagram of a detection device according to some embodiments of the present disclosure. Figure 1 and Figure 2As shown, the detection device generally includes a micro control unit (MCU) 1, and a zero-sequence current transformer coupled to the line of the circuit breaker circuit. The zero-sequence current transformer includes an induction coil 2, a detection winding 3 coupled to the induction coil 2, and a self-test winding 4. The detection winding 3 and the self-test winding 4 are respectively coupled to the control unit. Specifically, the micro control unit 1 includes an analog-to-digital conversion port (ADC) 11 and a digital-to-analog conversion port (DAC) 12. The detection winding 3 is coupled to the analog-to-digital conversion port 11, which is suitable for inducing an induction signal from the induction coil 2 at least during leakage or leakage detection, and sending a leakage signal related to the induction signal to the analog-to-digital conversion port 11 of the micro control unit 1. The self-test module is coupled to the digital-to-analog conversion port 12 of the micro control unit 1 to receive the self-test signal sent by the micro control unit 1.

[0033] In some embodiments, the zero-sequence current transformer further includes a sampling resistor 31. The sampling resistor 31 is connected in parallel to both ends of the detection winding 3. When the current in the induction coil 2 changes (for example, the vector sum of the currents of each phase in the line passing through the induction coil 2 is not zero), the detection winding 3 induces an induction signal from the induction coil 2 and converts it into a leakage signal through the sampling resistor 31.

[0034] In some embodiments, the detection device also includes a first operational amplifier 32, the two ends of which are coupled in parallel to the two ends of the sampling resistor 31, and are suitable for gain amplifying the leakage signal converted by the sampling resistor 31, converting the leakage signal into a voltage range signal suitable for detection by the micro control unit 1 (for example, 0~3V), and inputting the gain-amplified leakage signal into the analog-to-digital conversion port 11 of the micro control unit 1 for measurement by the micro control unit 1.

[0035] If leakage occurs in the load 9, the induction coil 2 of the circuit breaker detects leakage current in the line (for example, the vector sum of the three-phase current in the line is not zero), and an induction signal is induced in the self-detection winding 4 of the zero-sequence current transformer, and the induction signal is converted into a leakage signal through the sampling resistor 31. Further, the leakage signal is converted into a voltage range suitable for detection by the micro-control unit 1 after being processed by the first operational amplifier 32 and input to the analog-to-digital conversion port 11 of the micro-control unit 1. If the micro-control unit 1 detects that the leakage signal exceeds a predetermined threshold, the micro-control unit 1 sends a trip signal to control the solid-state switch 7 and the mechanical switch 6 to disconnect.

[0036] In some embodiments, the zero-sequence current transformer also includes a self-detection resistor 41, which is connected in series to one end of the self-detection winding 4 and is suitable for converting a self-detection signal into a self-detection current signal and injecting it into the induction coil 2, so that the detection winding 3 coupled to the induction coil 2 induces an induction signal.

[0037] In some embodiments, the detection device further includes a second operational amplifier 42, and the first operational amplifier 32 is connected in series between the self-test resistor 41 and the digital-to-analog conversion port 12 of the microcontroller unit 1. The first operational amplifier 32 is coupled to an end of the self-test resistor 41 away from the self-test winding.

[0038] In some embodiments, the microcontroller unit 1 further includes a manual detection button 16, which is suitable for being triggered by a user to send a manual detection instruction to the microcontroller unit 1. The microcontroller unit 1 can perform a manual self-test on the circuit breaker after receiving the manual detection instruction. In some embodiments, the microcontroller unit 1 can also perform an automatic self-test on the circuit breaker, and the microcontroller unit 1 can trigger the automatic detection process when a predetermined self-test cycle (e.g., 5s, 30s, 1min, 15min, 30min, 1h, 2h, 12h, 1week, 2week, etc.) is met.

[0039] If the circuit breaker needs to perform manual or automatic detection of the leakage detection function, the microcontroller unit 1 sends a self-detection signal (e.g., a sine wave voltage of 0V to 3V) to the self-detection winding 4 through the digital-to-analog conversion port 12. After the gain conversion of the second operational amplifier 42, it is converted into a leakage voltage signal suitable for injection into the induction coil 2 (e.g., a sine wave voltage of -3V to +3V). After receiving the self-detection signal, the self-detection winding 4 injects a self-detection current signal into the induction coil 2. At this time, the detection winding 3, which is also coupled to the induction coil 2, senses the induction signal from the induction coil 2, and after converting the induction signal into a leakage signal through the sampling resistor 31, it is converted into a voltage signal suitable for reception by the microcontroller unit 1 (e.g., 0V to 3V) after being processed by the first operational amplifier 32 and sent to the analog-to-digital conversion port 11 of the microcontroller unit 1.

[0040] For manual detection, after receiving the leakage signal, the micro control unit 1 determines that the strength of the sensing signal exceeds the threshold value and disconnects the solid-state switch 7 and then disconnects the mechanical switch 6 .

[0041] As for automatic detection, after receiving the leakage signal, the microcontroller unit 1 judges that the strength of the induced signal exceeds the threshold value and disconnects the solid-state switch 7, and after judging that the solid-state switch 7 is successfully disconnected within a predetermined time interval (e.g., 5ms), the solid-state switch 7 is controlled to be turned on again. In this way, the leakage function of the circuit breaker can be detected without powering off the load 9.

[0042] In some embodiments, the circuit breaker includes at least one solid-state switch 7. For example, the at least one solid-state switch 7 may be three solid-state switches 7, which are respectively arranged in three-phase circuits of the line to control the on and off of the three-phase circuits respectively.

[0043] Figure 3FIG. 1 is a schematic diagram showing a microcontroller unit 1 controlling a solid-state switch 7 and a mechanical switch 6 according to some embodiments of the present disclosure. Figure 3 As shown, in some embodiments, the micro control unit 1 includes a first control port 13, and the first control is coupled to the control side of the solid-state switch 7. The micro control unit 1 can send a control signal to the solid-state switch 7 through the first control port 13 to control the on and off of the solid-state switch 7.

[0044] In some embodiments, the solid-state switch 7 may include a metal-oxide semiconductor field effect transistor. The source and drain of the metal-oxide semiconductor field effect transistor are respectively coupled to the line, and the gate of the metal-oxide semiconductor field effect transistor is coupled to the first control port 13 of the micro control unit 1. The micro control unit 1 can output a control signal to the solid-state switch 7 through the first control port 13, thereby controlling the conduction or disconnection of the solid-state switch 7.

[0045] In some embodiments, the circuit breaker further includes at least one pair of voltage detection elements 71, and at least one pair of voltage detection elements 71 are respectively coupled to the two ends of at least one solid-state switch 7, for example, a pair of voltage detection elements 71 are respectively coupled to the source and drain of the metal-oxide semiconductor field effect transistor. The micro control unit 1 can detect the voltage on both sides of the solid-state switch 7 within a period of time (for example, 5ms) after the solid-state switch 7 performs an action through a pair of voltage detection elements 71, thereby determining whether the solid-state switch 7 is in action. For example, when the micro control unit 1 sends a control signal and controls the solid-state switch 7 to disconnect. If the micro control unit 1 detects a voltage change on both sides of the solid-state switch 7 (for example, when the solid-state switch 7 is turned on, the voltage difference on both sides is zero, and when the solid-state switch 7 is disconnected, a voltage difference appears on both sides), it can be confirmed that the solid-state switch 7 has successfully completed the action.

[0046] In some embodiments, the mechanical switch 6 may include a coil (or electromagnet) for controlling the opening (disconnection) or closing (conduction) of the mechanical switch 6. In some embodiments, the microcontroller unit 1 further includes a second control port 14, which is coupled to the coil of the mechanical switch 6 and is suitable for controlling the mechanical switch 6 to be turned on or off by controlling the coil to work.

[0047] When executing the trip command, the microcontroller unit 1 may first control the solid-state switch 7 to be disconnected, and after the microcontroller unit 1 confirms that the solid-state switch 7 is successfully disconnected, the microcontroller unit 1 controls the mechanical switch 6 to be disconnected through the second control port 14. Similarly, during the period when the microcontroller unit 1 controls the circuit breaker to be closed, the microcontroller unit 1 may first control the mechanical switch 6 to be closed, and then control the solid-state switch 7 to be closed. In this way, the arc generated by the mechanical switch 6 during the operation can be reduced, thereby improving the safety of the circuit breaker operation and extending the service life of the circuit breaker.

[0048] When the solid-state switch 7 is disconnected by self-test or remote command, it can be disconnected when the current passes through zero to extend the life of the solid-state switch; when the tripping command is executed due to leakage, the solid-state switch 7 does not need to pass through zero and is executed immediately.

[0049] In some embodiments, the detection device further comprises an auxiliary power supply 5, which is coupled to the power supply circuit and is adapted to supply power to at least the microcontroller unit 1. In some embodiments, the auxiliary power supply 5 is also adapted to supply power to a control module of the mechanical switch 6 and / or the solid-state switch 7, so that the corresponding control module can drive the mechanical switch 6 and / or the solid-state switch 7 to act (e.g., disconnect or conduct).

[0050] In some embodiments, the microcontroller unit 1 further includes a communication interface 15, which is suitable for connecting to an external device, so that the external device can obtain information stored in the microcontroller unit 1 (e.g., action information of each component during tripping) and / or load or modify configuration information to the microcontroller unit 1 through the communication interface 15. In some embodiments, if the circuit breaker detects that the leakage protection function fails, the circuit breaker can also report data such as fault parameters and / or fault causes to the remote host through the communication interface 15.

[0051] In some embodiments, the circuit breaker further includes a pair of sensors 8, which are respectively arranged on both sides of the solid-state switch 7 and the mechanical switch 6, and are suitable for detecting the current and voltage of the line.

[0052] The following will describe how to perform manual self-test and automatic self-test of a circuit breaker in conjunction with various embodiments.

[0053] For manual self-test, in some embodiments, after the user presses the manual test button 16, the manual test button 16 sends a manual test instruction to the microcontroller unit 1. After receiving the manual test instruction, the microcontroller unit 1 sends a self-test signal (e.g., a sine wave signal of 0V to 3V) to the self-test winding 4. The self-test signal is processed by the second operational amplifier 42 and converted into a voltage signal (e.g., a sine wave signal of -3 to +3V) suitable for injection into the self-test winding 4. The voltage signal is converted into a corresponding current signal through the self-test resistor 41 and input into the self-test winding 4. At this time, the detection winding 3 senses the current fluctuation of the self-test winding 4 through the induction coil 2, thereby generating an induction signal (e.g., an induction current), which is converted into a leakage signal (e.g., an induction voltage related to the induction current) through the self-test resistor 41. The leakage signal is converted into a voltage signal (e.g., 0V to 3V) suitable for reception by the microcontroller unit 1 after being processed by the first operational amplifier 32, and is input into the microcontroller unit 1 through the analog-to-digital conversion port 11. When the micro control unit 1 detects that the leakage signal is greater than a predetermined threshold, it controls the solid-state switch 7 to be disconnected, and controls the disconnection switch to be disconnected after the solid-state switch 7 is successfully disconnected.

[0054] For automatic self-test, in some embodiments, when the microcontroller unit 1 meets the preset period of automatic self-test (e.g., 12h), the microcontroller unit 1 sends a self-test signal (e.g., a sine wave signal of 0V to 3V) to the self-test winding 4, and the self-test signal is processed by the second operational amplifier 42 and converted into a voltage signal suitable for injection into the self-test winding 4 (e.g., a sine wave signal of -3 to +3V). The voltage signal is converted into a corresponding current signal through the self-test resistor 41 and input into the self-test winding 4. At this time, the detection winding 3 senses the current fluctuation of the self-test winding 4 through the induction coil 2, thereby generating an induction signal (e.g., an induction current). The induction signal is converted into a leakage signal (e.g., an induction voltage related to the induction current) through the self-test resistor 41. The leakage signal is converted into a voltage signal (e.g., 0V to 3V) suitable for reception by the microcontroller unit 1 after being processed by the first operational amplifier 32, and is input into the microcontroller unit 1 through the analog-to-digital conversion port 11. When the microcontroller unit 1 detects that the leakage signal is greater than a predetermined threshold, the solid-state switch 7 is controlled to be disconnected, and the microcontroller unit 1 controls the solid-state switch 7 to be turned on again within a certain time interval after determining that the solid-state switch 7 is successfully disconnected. Since the interval between the solid-state switch 7 being disconnected and being turned on again is very short during the automatic detection process (for example, it takes 5 ms to determine whether the solid-state switch 7 is actuated and 1 μs to perform the closing action of the solid-state switch), the load 9 connected to the circuit breaker will not lose power.

[0055] In some embodiments, in order to ensure that the micro-control unit 1 can accurately receive the leakage signal related to the detection signal, the intensity of the detection current injected into the detection winding 3 can be greater than or equal to twice the rated residual current. In this way, even if there is a residual current in the circuit that is opposite to the detection current, after the detection current is offset by the residual current, there can still be enough detection current detected by the micro-control unit 1 for the detection winding 3 to sense.

[0056] In some embodiments, the induction of the detection winding 3 is delayed, which results in a phase difference φ in the current actually detected. Therefore, the micro control unit 1 may be calibrated before the circuit breaker is used to reduce the error.

[0057] In some embodiments, the micro control unit 1 can also diagnose the location of a fault in the circuit breaker according to the action parameters of each component.

[0058] For example, during the manual detection process, the circuit breaker does not trip. If the micro control unit 1 detects only a 1.5V detection signal, it can be determined that the induction coil 2 is faulty.

[0059] During the manual detection process, the circuit breaker does not trip. If the micro control unit 1 cannot detect the detection signal, it can be determined that the circuit between the detection winding 3 and the micro control unit 1 is faulty.

[0060] During the manual detection process, the circuit breaker does not trip. If the micro control unit 1 detects the detection signal and detects that the voltage of the auxiliary power supply 5 is abnormal (for example, less than 10V), it can be determined that the auxiliary power supply 5 and / or related circuits are faulty.

[0061] During the manual detection process, the circuit breaker does not trip. If the micro control unit 1 detects the detection signal and detects that the voltage of the auxiliary power supply 5 is normal (for example, 13V), and the micro control unit 1 does not receive the feedback signal about the contact action of the mechanical switch 6, it can be determined that the coil (or electromagnet) used to drive the mechanical switch 6 to act is faulty.

[0062] During the manual detection process, the circuit breaker does not trip. If the microcontroller unit 1 detects the detection signal and detects that the voltage of the auxiliary power supply 5 is normal (for example, 13V), the feedback signal received by the microcontroller unit 1 about the contact action of the mechanical switch 6 is incomplete. At this time, it can be determined that the mechanical switch 6 is faulty.

[0063] In the automatic detection process, if the residual current corresponding to the detection signal detected by the micro control unit 1 is less than the rated residual current, and the micro control unit 1 only detects a detection signal of 1.5V, it can be determined that the induction coil 2 is faulty.

[0064] During the automatic detection process, if the residual current corresponding to the detection signal detected by the microcontroller unit 1 is less than the rated residual current and the microcontroller unit 1 cannot detect the detection signal, it can be determined that there is a circuit fault between the detection winding 3 and the microcontroller unit 1.

[0065] During the automatic detection process, if the residual current corresponding to the detection signal detected by the microcontroller unit 1 is less than the rated residual current, and the microcontroller unit 1 fails to execute the solid-state switch related actions (from closed->open->closed) or the voltage of the auxiliary power supply 5 is abnormal, it can be determined that the auxiliary power supply 5 and / or related circuits are faulty.

[0066] The above descriptions of various implementations of the present disclosure are exemplary, non-exhaustive, and not limited to the disclosed implementations. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described implementations. The selection of terms used herein is intended to best explain the principles of the implementations, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the various implementations disclosed herein.

Claims

1. A detection device for a circuit breaker, characterized in that: include: A micro control unit (1) comprises an analog-to-digital conversion port (11) and a digital-to-analog conversion port (12); as well as A zero-sequence current transformer is coupled in the circuit of the circuit breaker and comprises: an induction coil (2) wrapped around the circuit of the circuit breaker; A detection winding (3) coupled to the induction coil (2) and connected to the analog-to-digital conversion port (11) of the microcontroller unit (1) to induce a sensing signal from the induction coil (2) at least during a leakage period or a leakage detection period, and to send a leakage signal related to the sensing signal to the analog-to-digital conversion port (11); and The self-test winding (4) is coupled to the induction coil (2) and connected to the digital-to-analog conversion port (12) of the microcontroller unit (1) to receive a self-test signal sent by the microcontroller unit (1) via the digital-to-analog conversion port (12) to perform leakage detection.

2. The detection device according to claim 1, characterized in that: The zero-sequence current transformer also includes: The sampling resistor (31) is coupled to the detection winding (3) and is suitable for converting the induction signal into the leakage signal.

3. The detection device according to claim 1, characterized in that: The zero-sequence current transformer also includes: The self-detection resistor (41) is coupled to the self-detection winding (4) and is suitable for converting the self-detection signal into a self-detection current signal for injecting into the induction coil (2).

4. The detection device according to claim 1, characterized in that: It also includes a first operational amplifier (32) arranged between the detection winding (3) and the analog-to-digital conversion port (11).

5. The detection device according to claim 1, characterized in that: It also includes a second operational amplifier (42) arranged between the self-test winding (4) and the digital-to-analog conversion port (12).

6. The detection device according to claim 1, characterized in that: It also comprises an auxiliary power supply (5) coupled to the power supply circuit and suitable for supplying power to at least the micro control unit (1).

7. The detection device according to any one of claims 1 to 6, characterized in that: It also comprises a manual detection button (16), which is coupled to the micro control unit (1) and is suitable for being triggered to send a manual detection instruction to the micro control unit (1).

8. The detection device according to any one of claims 1 to 6, characterized in that: The micro control unit (1) further comprises: The communication interface (15) is suitable for connecting and communicating with external equipment.

9. A circuit breaker, characterized in that: include: A line connected between the power supply circuit and the load (9); At least one solid-state switch (7), arranged on the line and adapted to control the on and off of the line; A mechanical switch (6), arranged on the line and adapted to control the on and off of the line; as well as A detection device according to any one of claims 1 to 8, wherein the induction coil (2) of the detection device is arranged between the solid-state switch (7) and the mechanical switch (6).

10. The circuit breaker according to claim 9, characterized in that The solid-state switch (7) comprises a metal-oxide semiconductor field effect transistor.

11. The circuit breaker according to claim 10, characterized in that The micro control unit (1) further comprises: a first control port (13) coupled to the gate of the metal-oxide semiconductor field effect transistor.

12. The circuit breaker according to claim 9, characterized in that The micro control unit (1) further comprises: a second control port (14) coupled to the mechanical switch (6) to control the action of the mechanical switch (6).

13. The circuit breaker according to any one of claims 9 to 12, characterized in that: It also comprises at least one pair of voltage detection elements (71) arranged on both sides of the at least one solid-state switch (7) to respectively obtain voltage signals on both sides of the solid-state switch (7).

14. The circuit breaker according to claim 9, characterized in that It also includes a pair of sensors (8), which are arranged on both sides of the solid-state switch (7) and the mechanical switch (6) respectively and are suitable for detecting the current and voltage of the line.

Images