Leakage digital detection and fast protection method and circuit breaker

Abstract

The application relates to the field of electronic devices, and discloses a leakage current digital detection and rapid protection method and a circuit breaker. The circuit breaker comprises a leakage current detection circuit, a power supply rapid starting circuit, a power supply circuit and a circuit breaking driving circuit. The method specifically comprises the following steps: in the power grid power-off to power-on stage, directly obtaining the power supply output by the power supply rapid starting circuit, and stopping obtaining the power supply output by the power supply rapid starting circuit when the power supply output by the power supply circuit reaches a preset voltage value; after the power grid is powered on, receiving the power supply output by the power supply circuit; obtaining the leakage current detection signal output by the leakage current detection circuit after detecting the load voltage, and outputting a circuit breaking signal to the circuit breaking driving circuit when it is determined that the leakage current of the load is greater than or equal to a preset current value, so that the circuit breaking driving circuit drives the circuit breaker to break the circuit. The application solves the problem that when the circuit breaker adopts an MCU chip to digitally detect the leakage current, the protection and breaking of the load power supply time will exceed 40 ms.

Description

Technical Field

[0001] This invention relates to the field of electronic devices, and more particularly to a digital leakage current detection and rapid protection method and circuit breaker. Background Technology

[0002] Circuit breakers are essential protective devices used in power systems. They are primarily used to automatically disconnect circuits to prevent damage to electrical equipment and lines caused by faults such as overload and short circuits. To ensure the safe and stable operation of the power system, protect electrical equipment, and ensure personnel safety, the leakage tripping time of air circuit breakers must be within 40ms.

[0003] Traditional circuit breakers use mechanical structures for power-off detection, requiring manual adjustment of circuit board resistance parameters at the factory to adjust the leakage current threshold. This means the leakage current threshold cannot be adjusted on-site after the circuit breaker leaves the factory, and it's impossible to determine whether the tripping is due to a short circuit or leakage, nor can the circuit parameter data during operation be recorded. While using an MCU chip to record leakage current and other circuit parameter data can lead to a time exceeding 40ms between the circuit breaker being powered on and triggering leakage detection, posing a potential electrical safety hazard to downstream loads. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a digital leakage current detection and rapid protection method and circuit breaker, so as to solve the problem that the time for the circuit breaker to protect and disconnect the load power supply exceeds 40ms when using MCU chip for digital detection of leakage current.

[0005] The technical solution of the present invention is as follows:

[0006] A digital leakage current detection and rapid protection method is applied to a circuit breaker. The circuit breaker includes a leakage current detection circuit, a power supply rapid start-up circuit, a power supply circuit, and a circuit breaker drive circuit. The digital leakage current detection and rapid protection method specifically includes the following steps:

[0007] During the power grid outage and power-on phase, the power supply is directly obtained from the power supply fast start-up circuit, and the power supply is stopped when the power supply output from the power supply circuit reaches the preset voltage value.

[0008] After the power grid is powered on, it receives the power output from the power supply circuit;

[0009] Obtain the leakage current detection signal output by the leakage current detection circuit after detecting the load voltage;

[0010] When the leakage current of the load is determined to be greater than or equal to the preset current value based on the leakage current detection signal, a circuit breaker signal is output to the circuit breaker drive circuit so that the circuit breaker drive circuit drives the power-off device to disconnect the power supply to the load.

[0011] Optionally, when performing the step of obtaining the leakage current detection signal output by the leakage current detection circuit after detecting the load voltage, the method further includes:

[0012] Record the leakage current data of the load and the waveform of the leakage action.

[0013] Optionally, the digital leakage current detection and rapid protection method further includes the following steps:

[0014] When the leakage current of the load is determined to be less than the preset current value based on the leakage current detection signal, the power supply control signal is received, the power supply of the grid to the load is adjusted, and the leakage current value of the load is detected and recorded at the same time.

[0015] Optionally, the power supply circuit is a half-wave rectifier power supply circuit or a full-wave rectifier power supply circuit.

[0016] Optionally, the following steps are also included:

[0017] Receive the leakage current threshold adjustment signal and adjust the preset current value according to the leakage current threshold adjustment signal.

[0018] This invention also proposes a circuit breaker based on the above-mentioned digital leakage current detection and rapid protection method, comprising:

[0019] A leakage current detection circuit, wherein the detection terminal of the leakage current detection circuit is used to connect to a load, the leakage current detection circuit is used to detect the leakage current of the load, and outputs a leakage current detection signal;

[0020] An MCU control chip is provided, the input of which is connected to the output of the leakage current detection circuit. The MCU control chip is used to output a circuit breaker signal to the circuit breaker drive circuit when it is determined from the leakage current detection signal that the leakage current of the load is greater than or equal to a preset current value. The MCU control chip is also used to record leakage current parameters.

[0021] A power fast start circuit is provided, wherein the input terminal of the power fast start circuit is used to connect to the power grid, and the output terminal of the power fast start circuit is connected to the power supply terminal of the MCU control chip. The power fast start circuit is used to directly output power to the MCU control chip when the power grid is powered on.

[0022] A circuit breaker drive circuit is provided, wherein the input terminal of the circuit breaker drive circuit is connected to the output terminal of the MCU control chip, and the output terminal of the circuit breaker drive circuit is used to connect to a power-off device. The circuit breaker drive circuit is used to drive the power-off device to disconnect the load power supply when a circuit breaker signal is received.

[0023] Optionally, the circuit breaker further includes:

[0024] The power supply circuit has an input terminal for connecting to the power grid and an output terminal for connecting to the power supply terminal of the MCU control chip. The power supply circuit converts the power output from the power grid and outputs it to the MCU control chip. When the MCU control chip receives power output from the power supply circuit and the voltage reaches a preset value, it stops receiving power output from the power supply fast start circuit.

[0025] Optionally, the power fast start circuit includes a first MOSFET, a first resistor, a second resistor, a first diode, a second diode, and a third diode;

[0026] The drain of the first MOSFET is connected to the first power supply. The source of the first MOSFET is connected to the first end of the first resistor. The second end of the first resistor, the cathode of the first diode, the cathode of the second diode, and the first end of the second resistor are interconnected and connected to the power supply terminal of the MCU control chip. The anode of the second diode is connected to the second power supply. The second end of the second resistor, the cathode of the third diode, and the gate of the first MOSFET are interconnected. The anodes of the first diode and the anodes of the third diode are grounded.

[0027] Optionally, the power fast start circuit includes a second MOSFET, a third resistor, a fourth resistor, a fourth diode, and a fifth diode;

[0028] The drain of the second MOS transistor is connected to the third power supply. The source of the second MOS transistor is connected to the first end of the third resistor. The second end of the third resistor, the first end of the fourth resistor, and the cathode of the fourth diode are interconnected and connected to the power supply terminal of the MCU control chip. The anode of the fourth diode is connected to the fourth power supply. The gate of the second MOS transistor, the second end of the fourth resistor, and the cathode of the fifth diode are interconnected. The anode of the fifth diode is grounded.

[0029] Optionally, the power supply fast startup circuit includes a third MOSFET, a fifth resistor, a sixth resistor, a sixth diode, a first capacitor, a second capacitor, a first comparator, and a first voltage regulator;

[0030] The drain of the third MOSFET is connected to the fifth power supply. The gate of the third MOSFET, the first end of the fifth resistor, and the output of the first comparator are interconnected. The second end of the fifth resistor is connected to the power supply of the MCU control chip. The source of the third MOSFET is connected to the first end of the sixth resistor. The second end of the sixth resistor, the cathode of the sixth diode, the first end of the first capacitor, and the input of the first voltage regulator are interconnected. The anode of the sixth diode is connected to the sixth power supply. The output of the first voltage regulator and the first end of the second capacitor are connected, and are also connected to the power supply of the MCU control chip. The first input of the first comparator is connected to the power supply of the MCU control chip. The second output of the first comparator is connected to the sixth power supply. The second end of the first capacitor, the ground terminal of the first voltage regulator, and the second end of the second capacitor are grounded.

[0031] This invention utilizes a circuit breaker employing a digital leakage current detection and rapid protection method. When using an MCU control chip, the circuit breaker can supply power to the MCU control chip upon grid connection via a fast-start power circuit, allowing the MCU control chip to operate immediately and drive the disconnecting device to break the circuit when the load leakage current is large. Furthermore, the fast-start power circuit and the mains circuit supply power to the MCU control chip at different times during power-on. This ensures that the circuit breaker's disconnection time is within 40ms. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art 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 the structures shown in these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the method steps of an embodiment of the digital leakage current detection and rapid protection method of the present invention.

[0034] Figure 2 This is a schematic diagram of the method steps of another embodiment of the digital leakage current detection and rapid protection method of the present invention.

[0035] Figure 3 This is a schematic diagram of the method steps of another embodiment of the digital leakage current detection and rapid protection method of the present invention.

[0036] Figure 4 This is a schematic diagram of the method steps in another embodiment of the digital leakage current detection and rapid protection method of the present invention.

[0037] Figure 5 This is a functional module diagram of an embodiment of the circuit breaker of the present invention.

[0038] Figure 6 This is a schematic diagram of the circuit structure of an embodiment of the power supply fast start circuit in the circuit breaker of the present invention.

[0039] Figure 7 This is a schematic diagram of the circuit structure of another embodiment of the power supply fast start circuit in the circuit breaker of the present invention.

[0040] Figure 8 This is a schematic diagram of the circuit structure of another embodiment of the power supply fast start circuit in the circuit breaker of the present invention.

[0041] Figure 9 This is a schematic diagram of the circuit structure of a leakage current detection circuit in the circuit breaker of the present invention.

[0042] Figure 10 This is a schematic diagram of the circuit structure of an embodiment of the circuit breaker interruption drive circuit of the present invention.

[0043] Figure labeling: 10. Power supply fast start circuit; 21. Leakage detection circuit; 22. MCU control chip; 30. Circuit break drive circuit; 40. Power supply circuit; L. Mains; V1. First power supply; V2. Second power supply; V3. Third power supply; V4. Fourth power supply; V5. Fifth power supply; V6. Sixth power supply; V7. Seventh power supply; J1. Electrical interface; J2. Power-off device socket; U1. First voltage regulator; U2. First comparator; R1. First resistor; R2. Second resistor; R3. Third resistor; R4. Fourth resistor; R5. Fifth resistor; R6. Sixth resistor; R7. Seventh resistor; R8. Eighth resistor; R9. Ninth resistor; R10. Tenth resistor; R11. Eleventh resistor. Resistors: R12, twelfth resistor; R13, thirteenth resistor; R14, fourteenth resistor; C1, first capacitor; C2, second capacitor; C3, third capacitor; C4, fourth capacitor; C5, fifth capacitor; Q1, first MOSFET; Q2, second MOSFET; Q3, third MOSFET; Q4, fourth MOSFET; Q5, first transistor; D1, first diode; D2, second diode; D3, third diode; D4, fourth diode; D5, fifth diode; D6, sixth diode; D7, seventh diode; D8, eighth diode; D9, ninth diode; D10, tenth diode; D11, eleventh diode; D12, twelfth diode; D13, first thyristor. Detailed Implementation

[0044] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0045] In the implementation methods and claims, unless otherwise specified in the text, the terms "a," "an," "the," and "the" may also include plural forms. If the embodiments of the present invention involve descriptions of "first," "second," etc., such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0046] It should be further understood that the term "comprising" as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when an element is referred to as "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements present. Furthermore, "connected" or "coupled" as used herein can include wireless connections or wireless coupling. The term "and / or" as used herein includes all or any unit and all combinations of one or more associated listed items.

[0047] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0048] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0049] Circuit breakers are essential protective devices used in power systems. They are primarily used to automatically disconnect circuits to prevent damage to electrical equipment and lines caused by faults such as overload and short circuits. To ensure the safe and stable operation of the power system, protect electrical equipment, and ensure personnel safety, the leakage tripping time of air circuit breakers must be within 40ms.

[0050] Traditional circuit breakers use mechanical structures for power-off detection, requiring manual adjustment of the leakage threshold. Furthermore, they cannot determine whether the tripping is due to a short circuit or leakage, nor can they record the circuit parameters during operation. While using an MCU chip to record leakage and other circuit parameters can result in a time limit exceeding 40ms between power-on and leakage tripping, posing a safety hazard.

[0051] To address the aforementioned problems, this invention proposes a digital leakage current detection and rapid protection method, applicable to circuit breakers. The circuit breaker includes a leakage current detection circuit, a power supply rapid start-up circuit, a power supply circuit, and a circuit breaker drive circuit.

[0052] Reference Figure 1 In one embodiment, the digital leakage current detection and rapid protection method specifically includes the following steps:

[0053] S100. During the power grid outage to power-on phase, directly acquire the power output from the power supply fast start circuit and stop acquiring the power output from the power supply fast start circuit when the power received from the power supply circuit reaches the preset voltage value.

[0054] S110. During the period after the power grid is powered on, receive the power output from the power supply circuit;

[0055] S200: Obtain the leakage current detection signal output by the leakage current detection circuit after detecting the load voltage;

[0056] S300: When the leakage current of the load is determined to be greater than or equal to the preset current value based on the leakage current detection signal, the circuit breaker signal is output to the circuit breaker drive circuit so that the circuit breaker drive circuit drives the power-off device to disconnect the power supply to the load.

[0057] In this embodiment, after the power grid is powered on, the leakage current of the load is detected by the leakage current detection circuit, and an analog signal, namely the leakage current detection signal, is output. The analog signal is then acquired and converted into a digital signal to determine the magnitude of the leakage current. When the leakage current is greater than or equal to a preset current value, it indicates that the leakage current is large and there is a safety hazard. At this time, a corresponding electrical signal, namely the circuit breaker signal, is output to the circuit breaker drive circuit. The circuit breaker drive circuit can then output an electrical signal to the power-off device, causing the power-off device to disconnect the current in the circuit, thereby disconnecting the power supply to the load. Normally, after the power grid is powered on, the power output from the power grid needs to undergo rectification and voltage conversion steps before outputting a voltage to the MCU control chip for leakage current detection. In order to make the circuit breaker disconnect the circuit when the load experiences leakage after power-on within 40ms, this embodiment directly obtains the power output from the power supply fast start circuit. This allows for direct leakage current detection and subsequent control of the load without the need for the preceding power supply rectification and voltage conversion steps. This shortens the time required for the circuit breaker to disconnect the circuit when leakage occurs after power-on. It should be noted that the power supply circuit has high power but slow startup, while the power supply fast-start circuit has low power but fast startup. This embodiment combines the advantages of both power supplies, using the power supply fast-start circuit and the power supply circuit respectively at different power-on times, achieving seamless switching between the two power supplies. This ensures both rapid power supply and the normal operation of subsequent circuits. During the power grid's transition from outage to power-on, directly obtaining power from the grid allows for direct leakage current detection and subsequent control of the load, eliminating the need for pre-conversion and rectification steps. This shortens the time required for the circuit breaker to disconnect the circuit in case of leakage during the outage-to-power-on phase. Once the grid is back to normal power, the power supply circuit is used. This enables full-time leakage current detection and protection.

[0058] This invention utilizes a circuit breaker employing a digital leakage current detection and rapid protection method. When the circuit breaker uses an MCU control chip, a rapid power-start circuit supplies power to the MCU control chip upon grid connection, allowing the MCU control chip to operate immediately and drive the disconnecting device to break the circuit when the load leakage current is large. This ensures that the circuit breaker disconnects the load power supply within 40ms.

[0059] Reference Figure 2 In one embodiment, the step of obtaining the leakage current detection signal output by the leakage current detection circuit after detecting the load voltage further includes:

[0060] S210: Record the leakage current data of the load and the waveform of the leakage action.

[0061] In this embodiment, the leakage current parameters of the load and other circuit parameters, such as the waveform of leakage action, are recorded during the operation of the circuit breaker. This allows users or maintenance personnel to view the data or implement a safety warning function.

[0062] Reference Figure 3 In one embodiment, the digital leakage current detection and rapid protection method further includes the following steps:

[0063] S400: When the leakage current of the load is determined to be less than the preset current value based on the leakage current detection signal, the power supply control signal is received, the power supply of the grid to the load is adjusted, and the leakage current value of the load is detected and recorded.

[0064] In this embodiment, when the leakage current of the load is less than a preset current value, it indicates that the leakage current is small and there is no safety hazard. At this time, a power supply control signal can be received to adjust the power supply from the grid to the load. The power supply control signal can be output manually or from a remote control terminal. Simultaneously, the leakage current value of the load is detected and recorded, thus providing users with real-time leakage current monitoring data.

[0065] In one embodiment, the power supply circuit is a half-wave rectified power supply circuit or a full-wave rectified power supply circuit.

[0066] In this embodiment, the power supply circuit can use half-wave rectification, which will have no voltage for half a cycle; or it can use full-wave rectification, which requires an isolated power supply and will increase the size of the circuit breaker. The choice between half-wave rectification power supply circuit and full-wave rectification power supply circuit can be made according to the actual situation and user needs.

[0067] Reference Figure 4 In one embodiment, the digital leakage current detection and rapid protection method further includes the following steps:

[0068] S500 receives the leakage current threshold adjustment signal and adjusts the preset current value according to the leakage current threshold adjustment signal.

[0069] In this embodiment, the leakage current threshold adjustment signal output by an external terminal, such as a mobile phone or Bluetooth device, can be received through the communication function, allowing the user to remotely adjust the leakage current threshold or control other functions.

[0070] Based on the above-mentioned digital leakage current detection and rapid protection method, this invention also proposes a circuit breaker.

[0071] Reference Figure 5 In one embodiment, the circuit breaker includes:

[0072] Leakage detection circuit 21, wherein the detection terminal of the leakage detection circuit 21 is used to connect to the load, the leakage detection circuit 21 is used to detect the leakage current of the load, and outputs a leakage detection signal;

[0073] The MCU control chip 22 has its input terminal connected to the output terminal of the leakage current detection circuit 21. The MCU control chip 22 is used to output a circuit breaker signal to the circuit breaker drive circuit when it is determined from the leakage current detection signal that the leakage current of the load is greater than or equal to a preset current value. The MCU control chip 22 is also used to record leakage current parameters.

[0074] A power fast start circuit 10 is provided, wherein the input terminal of the power fast start circuit 10 is connected to the power grid L, and the output terminal of the power fast start circuit 10 is connected to the power supply terminal of the MCU control chip 22. The power fast start circuit 10 is used to directly output power to the MCU control chip 22 when the power grid L is powered on.

[0075] The circuit breaker drive circuit 30 has its input terminal connected to the output terminal of the MCU control chip 22, and its output terminal used to connect to the power-off device. The circuit breaker drive circuit 30 is used to drive the power-off device to disconnect the load power supply when it receives a circuit breaker signal.

[0076] In this embodiment, the leakage current detection circuit 21 can be composed of multiple electronic components such as capacitors, diodes, and resistors. It detects the leakage current of the load and outputs an analog signal. The MCU control chip 22 then converts the analog signal into a digital signal to determine the magnitude of the leakage current. When the leakage current exceeds a preset current value within the MCU control chip 22, it indicates a large leakage current and a safety hazard. In this case, the MCU control chip 22 outputs a corresponding electrical signal, i.e., a circuit breaker signal, to the circuit breaker drive circuit 30. The circuit breaker drive circuit 30 can be composed of multiple capacitors, resistors, and switching devices. It drives the switching on and off of the power-off device. The power-off device can be an electromagnet or a mechanical switch, such as the electromagnet in a circuit breaker. During normal operation, the electromagnet remains closed. When the drive circuit receives the circuit breaker signal, it outputs an electrical signal to the electromagnet, causing the electromagnet to disconnect the current in the circuit, thus breaking the circuit. The MCU control chip 22 can be an RN8211B-V3 MCU chip or other chips with the same function. The MCU control chip 22 can also record the leakage current parameters and other circuit parameters of the circuit breaker during operation, making it convenient for users or maintenance personnel to view or implement safety warning functions. Furthermore, the MCU control chip 22 can also perform communication functions, allowing users to remotely adjust the leakage current threshold or control other functions.

[0077] It should be noted that, typically during the power grid L's transition from power outage to power-on, the power output from grid L requires rectification and voltage conversion before being supplied to the MCU control chip 22. To ensure that the circuit breaker can disconnect the circuit within 40ms when a load leakage occurs after power-on, this embodiment also includes a fast-start power circuit 10. The fast-start power circuit 10 can be composed of electronic components such as switches, resistors, or capacitors. It connects grid L and the power supply terminals of the MCU control chip 22, directly supplying power to the MCU control chip 22 during the power grid L's transition from power outage to power-on. This allows the MCU control chip 22 to directly detect leakage current and perform subsequent control of the load without the need for prior rectification and voltage conversion. This shortens the time required for the circuit breaker to disconnect the circuit when a load leakage occurs after power-on. After grid L is powered on normally, the power supply circuit supplies power to the MCU control chip 22. This enables full-time leakage current detection and protection.

[0078] The circuit breaker in this solution allows the MCU control chip 22 to be powered on by the power fast start circuit 10 when the mains L is powered on. This enables the MCU control chip 22 to immediately detect and control leakage current, and drive the power-off device to disconnect the circuit when the leakage current is large. Thus, the circuit breaker disconnection time is within 40ms.

[0079] Reference Figure 6 In one embodiment, the power fast start circuit 10 includes a first MOSFET Q1, a first resistor R1, a second resistor R2, a first diode D1, a second diode D2, and a third diode D3;

[0080] The drain of the first MOSFET Q1 is connected to the first power supply V1. The source of the first MOSFET Q1 is connected to the first end of the first resistor R1. The second end of the first resistor R1, the cathode of the first diode D1, the cathode of the second diode D2, and the first end of the second resistor R2 are interconnected and connected to the power supply terminal of the MCU control chip 22. The anode of the second diode D2 is connected to the second power supply V2. The second end of the second resistor R2, the cathode of the third diode D3, and the gate of the first MOSFET Q1 are interconnected. The anodes of the first diode D1 and the anodes of the third diode D3 are grounded.

[0081] For three-phase AC power, the power supply fast start-up circuit 10 in this embodiment can be used for fast power start-up. The first MOSFET Q1 can be a depletion-type PMOS transistor, and the first transistor Q5 and the third transistor can be Zener diodes. When power is first applied, the depletion-type PMOS transistor is in the on state, and the first power supply V1 can be the mains power L. The first power supply V1 is directly output to the power supply terminal of the MCU control chip 22 through the first MOSFET Q1 and the first resistor R1 to supply power to the MCU control chip 22. At this time, the power supply circuit 40 in the circuit breaker will perform rectification and voltage conversion on the mains power L, converting it into a suitable operating voltage and outputting the second power supply V2. This output is then sent to the power supply terminal of the MCU control chip 22 through the second diode D2. Furthermore, the voltage at the cathode of the third diode D3 will increase with the output of the first power supply V1 and the second power supply V2. When the breakdown voltage of the third diode D3 is reached, the third diode D3 reverse-biased conducts, pulling the gate voltage of the first MOSFET Q1 down to ground. At this point, the gate-source voltage difference of the first MOSFET Q1 is less than the turn-on voltage, the first MOSFET Q1 turns off, and the power fast start circuit 10 stops outputting power to the power supply terminal of the MCU control chip 22. The third power supply V3 then supplies power to the MCU control chip 22. The breakdown voltage of the third diode D3 can be selected according to the actual situation and user requirements.

[0082] Reference Figure 7 In one embodiment, the power fast start circuit 10 includes a second MOSFET Q2, a third resistor R3, a fourth resistor R4, a fourth diode D4, and a fifth diode D5;

[0083] The drain of the second MOSFET Q2 is connected to the third power supply V3. The source of the second MOSFET Q2 is connected to the first end of the third resistor R3. The second end of the third resistor R3, the first end of the fourth resistor R4, and the cathode of the fourth diode D4 are interconnected and connected to the power supply terminal of the MCU control chip 22. The anode of the fourth diode D4 is connected to the fourth power supply V4. The gate of the second MOSFET Q2, the second end of the fourth resistor R4, and the cathode of the fifth diode D5 are interconnected. The anode of the fifth diode D5 is grounded.

[0084] For single-phase AC power, the power supply fast start circuit 10 in this embodiment can be used for fast power start-up. The second MOSFET Q2 can be a depletion-type PMOS transistor, and the fifth diode D5 can be a transient suppression diode. When power is first applied, the depletion-type PMOS transistor is in the on state, and the third power supply V3 can be the mains power L. The third power supply V3 is directly output to the power supply terminal of the MCU control chip 22 through the second MOSFET Q2 and the third resistor R3 to supply power to the MCU control chip 22. At this time, the power supply circuit 40 in the circuit breaker will perform rectification and voltage conversion on the mains power L, converting it to a suitable operating voltage and outputting the fourth power supply V4. This output is then sent to the power supply terminal of the MCU control chip 22 via the fourth diode D4. Furthermore, the voltage at the cathode of the fifth diode D5 will increase with the output of the third power supply V3 and the fourth power supply V4. When the breakdown voltage of the fifth diode D5 is reached, the fifth diode D5 reverse-biased conducts, pulling the gate voltage of the second MOSFET Q2 down to ground. At this point, the gate-source voltage difference of the second MOSFET Q2 is less than the turn-on voltage, the second MOSFET Q2 turns off, and the power supply fast start circuit 10 stops outputting power to the power supply terminal of the MCU control chip 22. The third power supply V3 then supplies power to the MCU control chip 22. The breakdown voltage of the fifth diode D5 can be selected according to the actual situation and user requirements. Additionally, Figure 7 In this context, N can represent the zero line.

[0085] Reference Figure 8 In one embodiment, the power fast start circuit 10 includes a third MOSFET Q3, a fifth resistor R5, a sixth resistor R6, a sixth diode D6, a first capacitor C1, a second capacitor C2, a first comparator U2, and a first voltage regulator U1.

[0086] The drain of the third MOSFET Q3 is connected to the fifth power supply V5. The gate of the third MOSFET Q3, the first end of the fifth resistor R5, and the output of the first comparator U2 are interconnected. The second end of the fifth resistor R5 is connected to the power supply of the MCU control chip 22. The source of the third MOSFET Q3 is connected to the first end of the sixth resistor R6. The second end of the sixth resistor R6, the cathode of the sixth diode D6, the first end of the first capacitor C1, and the input of the first voltage regulator U1 are interconnected. The anode of the sixth diode D6 is connected to the sixth power supply V6. The output of the first voltage regulator U1 and the first end of the second capacitor C2 are connected and connected to the power supply of the MCU control chip 22. The first input of the first comparator U2 is connected to the power supply of the MCU control chip 22. The second output of the first comparator U2 is connected to the sixth power supply V6. The second end of the first capacitor C1, the ground of the first voltage regulator U1, and the second end of the second capacitor C2 are grounded.

[0087] For single-phase AC power, the power supply fast start circuit 10 of this embodiment can also be used for fast power start-up. Upon power-on, the voltage at the power supply terminal of the MCU control chip 22 is 0, the sixth power supply V6 is also 0, the first comparator U2 cannot operate, the gate of the third MOSFET Q3 is connected to the power supply terminal of the MCU control chip 22 via the fifth resistor R5, therefore the gate potential is 0, the voltage of the first capacitor C1 is 0, so the source potential of the third MOSFET Q3 is also 0, the gate-source voltage difference of the third MOSFET Q3 is 0V, and the third MOSFET Q3 is turned on.The fifth power supply V5 can be the mains power supply L, and the sixth power supply V6 can be the power output after the mains power supply L is converted by the front-end power supply circuit 40. The fifth power supply V5 directly charges the first capacitor C1 and supplies power to the load at the back end of the first regulator U1 through the circuit of the third MOSFET Q3 and the sixth resistor R6. As the first capacitor C1 and the second capacitor C2 are charged, the voltage at the power supply terminal of the MCU control chip 22 and the voltage at the first capacitor C1 gradually rise. Before the voltage at the power supply terminal of the MCU control chip 22 rises to the regulated voltage value of 3.3V of the first regulator U1, the gate voltage of the third MOSFET Q3 is equal to the power supply terminal voltage of the MCU control chip 22, and the source voltage of the third MOSFET Q3 is equal to the voltage at the MCU control chip 22. The power supply voltage of chip 22 is such that the gate-source voltage difference of the third MOSFET Q3 is approximately 0V, and it remains in a conducting state, continuously supplying power from the high-voltage fifth power supply V5 to the subsequent stage. Once the power supply voltage of the MCU control chip 22 rises to the regulated value of the first regulator U1 (3.3V), the power supply voltage of the MCU control chip 22 remains constant at 3.3V. The sixth power supply V6, due to the slower startup of the preceding power supply circuit 40, has a lower voltage than the power supply voltage of the MCU control chip 22. The first comparator U2 continuously outputs a high level, meaning the gate voltage of the third MOSFET Q3 equals the power supply voltage of the MCU control chip 22, which is 3.3V. Meanwhile, the voltage of the first capacitor C1 increases with the power supply voltage V5 flowing through the third MOSFET... As the charging of transistor Q3 increases, the source voltage of the third MOSFET Q3 also rises. The gate-source voltage difference of the third MOSFET Q3 gradually approaches the turn-off threshold, causing its conduction capability to decrease. Balance is achieved when the current flowing through the third MOSFET Q3 equals the load current. At this point, the voltage of the first capacitor C1 is approximately the turn-off threshold of the third MOSFET Q3 plus the power supply voltage of the MCU control chip 22. The turn-off threshold of the third MOSFET Q3 is between -1.5V and -3.3V. Therefore, the voltage of the first capacitor C1 is 3.3 + 1.5 = 4.8V to 3.3 + 3.3 = 6.6V. If the sixth power supply V6 rises to 5V, the sixth power supply V6, after passing through the first... After voltage regulator U1, the voltage drops to 4.6V, which may prevent the third MOSFET Q3 from being completely turned off, potentially causing it to burn out due to prolonged power supply. Therefore, a first comparator U2 is added to assist in the turn-off process. As long as the voltage of the sixth power supply V6 rises higher than the power supply voltage of the MCU control chip 22, the first comparator U2 will output 0V. The source voltage of the third MOSFET Q3, i.e., the voltage of the first capacitor C1, only needs to reach 3.3V to turn off the third MOSFET Q3. After the front-stage power supply circuit 40 is fully operational, it can raise the voltage of the first capacitor C1 to 4.6V, completely turning off the third MOSFET Q3, thus achieving the switching from power supply from the fast-start circuit 10 to mains power L. Additionally... Figure 8 In this context, N can represent the zero line.

[0088] Furthermore, referring to Figure 9 In one embodiment, the leakage detection circuit 21 includes a seventh diode D7, an eighth diode D8, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a third capacitor C3, and a fourth capacitor C4.

[0089] The cathode of the seventh diode D7, the anode of the eighth diode D8, the first terminal of the seventh resistor R7, and the first terminal of the eighth resistor R8 are interconnected and used to connect to the first terminal of the electrical interface J1. The anode of the seventh diode D7, the cathode of the eighth diode D8, the second terminal of the seventh resistor R7, and the first terminal of the ninth resistor R9 are interconnected and used to connect to the second terminal of the electrical interface J1. The second terminal of the eighth resistor R8 is interconnected with the first terminal of the third capacitor C3 and connected to the input terminal of the MCU control chip 22. The second terminal of the ninth resistor R9 is interconnected with the first terminal of the fourth capacitor C4 and connected to the input terminal of the MCU control chip 22. The second terminal of the third capacitor C3 and the second terminal of the fourth capacitor C4 are connected and grounded.

[0090] In this embodiment, electrical interface J1 is used to connect the load. The seventh diode D7 and the eighth diode D8 provide voltage limiting protection. When the voltage at the first terminal of electrical interface J1 is higher than the voltage at the second terminal and exceeds a certain value, the seventh diode D7 conducts, limiting the voltage within a safe range. Similarly, when the voltage at the second terminal of electrical interface J1 is higher than the voltage at the first terminal and exceeds a certain value, the eighth diode D8 conducts, also limiting the voltage within a safe range, thus protecting the subsequent resistors, capacitors, and MCU control chip 22 from damage by high voltage. The seventh resistor R7 provides current limiting, while the eighth resistor R8 and the ninth resistor R9 provide voltage division. The third capacitor C3 and the fourth capacitor C4 provide filtering. Thus, the leakage detection circuit 21 in this embodiment achieves accurate detection of load leakage through the voltage limiting protection of the diodes, the voltage division and current limiting of the resistors, and the filtering effect of the capacitors.

[0091] Reference Figure 10 In one embodiment, the circuit breaker drive circuit 30 includes a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a ninth diode D9, a tenth diode D10, an eleventh diode D11, a twelfth diode D12, a first thyristor D13, a first transistor Q5, a fourth MOSFET Q4, and a fifth capacitor C5.

[0092] The first end of the tenth resistor R10 is connected to the output terminal of the MCU control chip 22. The second end of the tenth resistor R10 is connected to the anode of the ninth diode D9. The first end of the eleventh resistor R11 is connected to the output terminal of the MCU control chip 22. The second end of the eleventh resistor R11, the anode of the tenth diode D10, and the drain of the fourth MOS transistor Q4 are interconnected. The gate of the fourth MOS transistor Q4 is connected to the output terminal of the MCU control chip 22. The source of the fourth MOS transistor Q4 is grounded. The cathodes of the ninth diode D9 and the tenth diode D10, the base of the first transistor Q5, and the first end of the twelfth resistor R12 are interconnected. The second end of the twelfth resistor R12 is grounded. The collector of the first transistor Q5 is connected to the... The first end of the thirteenth resistor R13 is connected, and the second end of the thirteenth resistor R13 is connected to the power supply terminal of the MCU control chip 22. The emitter of the first transistor Q5, the first end of the fourteenth resistor R14, the first end of the fifth capacitor C5, and the gate of the first thyristor D13 are interconnected. The second end of the fourteenth resistor R14, the second end of the fifth capacitor C5, and the cathode of the first thyristor D13 are grounded. The anode of the first thyristor D13 is connected to the cathode of the eleventh diode D11. The anode of the eleventh diode D11 is connected to the anode of the twelfth diode D12 and is used to connect to the first end of the power-off device socket J2. The cathode of the twelfth diode D12 is used to connect to the seventh power supply V7 and is used to connect to the second end of the power-off device socket J2.

[0093] In this embodiment, the tenth resistor R10 and the eleventh resistor R11 serve as current limiters; the twelfth resistor R12 serves as both current limiter and voltage divider, ensuring the normal operation of the first transistor Q5; the thirteenth resistor R13 serves as a pull-up resistor, providing power to the collector of the first transistor Q5; and the fourteenth resistor R14 serves as a current-limiting resistor, limiting the current flowing into the gate of the first thyristor D13 to prevent excessive gate current from damaging the thyristor. The ninth diode D9 and the tenth diode D10 serve as isolation and rectification. They isolate the signals output by the MCU control chip 22, preventing signal interference, and simultaneously rectify the high-level signal to provide a forward bias voltage to the base of the first transistor Q5. The eleventh diode D11 and the twelfth diode D12 serve as isolation and protection. The eleventh diode D11 prevents current from flowing back into the first thyristor D13, while the twelfth diode D12 is used to connect to the seventh power supply V7, providing a suitable drive voltage for the power-off device and also preventing current from flowing back. The first transistor Q5 acts as an amplification and switching element. When its base receives a suitable bias voltage, it conducts, amplifying the signal output by the MCU control chip 22 and providing sufficient trigger current to the gate of the first thyristor D13. The first thyristor D13 acts as a switching element, conducting after receiving a trigger signal at its gate, providing drive current to the power-off device, thereby controlling the operation of the power-off device. Once conducting, it will remain on as long as there is sufficient current between the anode and cathode, until the anode current is less than the holding current before turning off. The fourth MOSFET Q4 acts as a switching element, controlling the circuit's on / off state according to the signal output by the MCU control chip 22. It conducts when its gate receives a high-level signal, providing a path for subsequent circuits; it turns off when it receives a low-level signal, cutting off the circuit. The fifth capacitor C5 serves as a filter and delay element. In the gate circuit of the first thyristor D13, the capacitor can filter out high-frequency interference signals, making the trigger signal more stable; at the same time, the charging and discharging process of the capacitor can provide a certain delay, preventing false triggering. It should be noted that in this embodiment, the first end of the tenth resistor R10 is connected to the output terminal of the MCU control chip 22, and is used to receive the remote opening and closing command signal output by the MCU control chip 22. That is, the user can control the power-off device to close or open through the MCU control chip 22. The first end of the eleventh resistor R11 is connected to the output terminal of the MCU control chip 22, and is used to receive the leakage protection tripping signal output by the MCU control chip 22. That is, when the MCU control chip 22 detects leakage in the power grid L, it outputs a circuit breaker signal to the first end of the eleventh resistor R11, thereby controlling the power-off device to open. The gate of the fourth MOSFET Q4 is used to receive the contact status signal output by the MCU control chip 22, which can prevent the power-off device from reclosing due to leakage current drive when it is open. The seventh power supply V7 can be output from the front-end power supply circuit 40.

[0094] Reference Figure 5 In one embodiment, the circuit breaker further includes:

[0095] The power supply circuit 40 has an input terminal for connecting to the power grid and an output terminal for connecting to the power supply terminal of the MCU control chip 22. The power supply circuit 40 converts the output voltage of the power grid and outputs it to the MCU control chip 22. When the MCU control chip 22 receives the power output from the power supply circuit 40 and it reaches a preset voltage value, it stops receiving the power output from the power fast start circuit 10.

[0096] In this embodiment, the power supply circuit 40 can be composed of electronic components such as capacitors, resistors, inductors, and diodes. The power supply circuit 40 can rectify, filter, and transform the output voltage of the mains power supply before outputting it to the MCU control chip 22 for normal power supply. The specific circuit structure of the power supply circuit 40 can be referred to Figure 6 , Figure 7 and Figure 8 For different power supply fast start circuits 10, a corresponding power supply circuit 40 can be configured to perform power conversion. When the power output from the power supply circuit 40 reaches a preset voltage value, the MCU control chip 22 stops receiving power from the power supply fast start circuit 10, thus achieving seamless switching between the two power supplies.

[0097] In one embodiment, the power supply circuit 40 is a half-wave rectifier power supply circuit 40 or a full-wave rectifier power supply circuit 40.

[0098] In this embodiment, the power supply circuit 40 in the circuit breaker can be a half-wave rectifier paired with an MCU chip, but half-wave rectification will have no voltage for half a cycle; or it can be a full-wave rectifier, but full-wave rectification requires an isolated power supply, which will increase the size of the circuit breaker; the choice between a half-wave rectifier power supply circuit 40 and a full-wave rectifier power supply circuit 40 can be made according to the actual situation and user requirements.

[0099] To better illustrate the technical concept of the present invention, in conjunction with the above embodiments and... Figures 1 to 10 Explanation:

[0100] First, the entire process from powering on the power grid L to detecting load leakage and triggering the leakage trip includes powering on the power grid L, providing stable power to the MCU control chip 22, the MCU control chip 22 detecting leakage, triggering leakage control, and the circuit breaker drive circuit 30 driving the electromagnet to open and extinguish the arc. Specifically, the time from providing stable power to the MCU control chip 22 to detecting leakage is fixed at 10ms; the time from detecting leakage to triggering leakage control is 3ms to 5ms; and the time from the circuit breaker drive circuit 30 driving the electromagnet to open is 1ms. It should be noted that the power-on process using the fast-start circuit 10 in this scheme takes 1ms to 2ms, while powering on via the power supply circuit 40 takes 15ms to 20ms. When using half-wave rectification, it takes 0ms to 10ms for the leakage current control to be triggered and for the circuit breaker drive circuit 30 to drive the electromagnet to open the gate. Tripping and arc extinguishing require crossing the zero point, so it also takes 0ms to 10ms. Using half-wave rectification may also result in a loss of 0ms to 10ms during power-on.

[0101] The circuit breaker in this solution can control the entire process within 40ms; taking a power grid frequency of 50 Hz as an example, one AC wavelength cycle is 20ms. In this scheme, the time required from the power-on of the MCU control chip 22 to triggering the leakage current control is fixed at 14ms to 17ms. With half-wave rectification, 0ms to 10ms is positive current with voltage, 10ms to 20ms is negative current with no voltage, and so on. Assuming that the grid L is powered on at 10ms with no voltage, and voltage is only available at 20ms, 10ms has already been lost. After the MCU control chip 22 powers on and the leakage current control is triggered, which is 17ms, the current is positive and there is voltage at 27ms. At this time, the circuit breaker drive circuit 30 can directly drive the electromagnet to open the gate without losing time. After another 1ms, the circuit breaker drive circuit 30 drives the electromagnet to open the gate, which is 28ms, with positive current. The current crosses zero at 30ms, thus achieving tripping and arc extinguishing. Even if the arc extinguishing cannot be achieved at 30ms due to circuit delay or other reasons, it can still achieve tripping and arc extinguishing when it crosses zero again at 40ms. Therefore, the time from when the circuit breaker is powered on by the power grid L to when it detects load leakage and triggers the leakage trip action will not exceed 40ms.

[0102] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for detecting and quickly protecting against electric leakage, applied to a circuit breaker, characterized in that, The circuit breaker comprises a leakage detection circuit, a power supply quick start circuit, a power supply circuit and a circuit breaker driving circuit, and the power supply quick start circuit comprises: a first MOS tube, a first resistor, a second resistor, a first diode, a second diode and a third diode; the drain of the first MOS tube is used for connecting a first power supply, the source of the first MOS tube and the first end of the first resistor are connected, the second end of the first resistor, the cathode of the first diode, the cathode of the second diode and the first end of the second resistor are interconnected and connected with the power supply end of the MCU control chip, the anode of the second diode is used for connecting a second power supply, the second end of the second resistor, the cathode of the third diode and the gate of the first MOS tube are interconnected, the anode of the first diode and the anode of the third diode are grounded; or, a second MOS tube, a third resistor, a fourth resistor, a fourth diode and a fifth diode; the drain of the second MOS tube is used for connecting a third power supply, the source of the second MOS tube and the first end of the third resistor are connected, the second end of the third resistor, the first end of the fourth resistor and the cathode of the fourth diode are interconnected and connected with the power supply end of the MCU control chip, the anode of the fourth diode is used for connecting a fourth power supply, the gate of the second MOS tube, the second end of the fourth resistor and the cathode of the fifth diode are interconnected, and the anode of the fifth diode is grounded; or, a third MOS tube, a fifth resistor, a sixth resistor, a sixth diode, a first capacitor, a second capacitor, a first comparator and a first voltage stabilizer; the drain of the third MOS tube is used for connecting a fifth power supply, the gate of the third MOS tube, the first end of the fifth resistor and the output end of the first comparator are interconnected, the second end of the fifth resistor is connected with the power supply end of the MCU control chip, the source of the third MOS tube is connected with the first end of the sixth resistor, the second end of the sixth resistor, the cathode of the sixth diode, the first end of the first capacitor and the input end of the first voltage stabilizer are interconnected, the anode of the sixth diode is used for connecting a sixth power supply, the output end of the first voltage stabilizer and the first end of the second capacitor are connected and connected with the power supply end of the MCU control chip, the first input end of the first comparator is connected with the power supply end of the MCU control chip, the second output end of the first comparator is used for connecting the sixth power supply, and the second end of the first capacitor, the ground end of the first voltage stabilizer and the second end of the second capacitor are grounded. The leakage digital detection and quick protection method specifically comprises the following steps: in the power grid power-off to power-on stage, directly acquiring the power supply output by the power supply quick start circuit and stopping acquiring the power supply output by the power supply quick start circuit when the power supply output by the power supply circuit reaches a preset voltage value; in the stage after the power grid is powered on, receiving the power supply output by the power supply circuit; acquiring the leakage current detection signal output by the leakage detection circuit after detecting the load voltage; When the leakage current of the load is determined to be greater than or equal to the preset current value according to the leakage current detection signal, a circuit breaking signal is output to the circuit breaking driving circuit to drive the circuit breaker to disconnect the power supply of the load.

2. The leakage current digitization detection and fast protection method of claim 1, wherein, The step of acquiring the leakage current detection signal output by the leakage detection circuit after detecting the load voltage further includes: The leakage current data of the load and the waveform of the leakage action are recorded.

3. The leakage current digitization detection and fast protection method of claim 1, wherein, The leakage digital detection and rapid protection method further includes the following steps: When the leakage current of the load is determined to be less than the preset current value according to the leakage current detection signal, a power supply control signal is received, the power supply of the load by the power grid is adjusted, and the leakage current value of the load is detected and recorded.

4. The leakage current digitization detection and fast protection method of claim 1, wherein, The power supply circuit is a half-wave rectification power supply circuit or a full-wave rectification power supply circuit.

5. The leakage current digitization detection and fast protection method of claim 1, wherein, The method further includes the following steps: A leakage threshold adjustment signal is received, and the size of the preset current value is adjusted according to the leakage threshold adjustment signal.

6. A circuit breaker based on the method for detecting and fast protecting of leakage current digitization according to any one of claims 1-5, characterized in that, The method includes: A leakage detection circuit, the detection end of the leakage detection circuit is used to connect the load, the leakage detection circuit is used to detect the leakage current of the load, and a leakage detection signal is output; An MCU control chip, the input end of the MCU control chip is connected with the output end of the leakage detection circuit, the MCU control chip is used to output a circuit breaking signal to the circuit breaking driving circuit when the leakage current of the load is determined to be greater than or equal to the preset current value according to the leakage current detection signal; the MCU control chip is also used to record the leakage current parameter; A power supply rapid starting circuit, the input end of the power supply rapid starting circuit is used to connect the power grid, the output end of the power supply rapid starting circuit is connected with the power supply end of the MCU control chip, and the power supply rapid starting circuit is used to directly output power to the MCU control chip when the power grid is powered on; A circuit breaking driving circuit, the input end of the circuit breaking driving circuit is connected with the output end of the MCU control chip, the output end of the circuit breaking driving circuit is used to connect the circuit breaker, and the circuit breaking driving circuit is used to drive the circuit breaker to disconnect the power supply of the load when the circuit breaking signal is received.

7. The circuit breaker of claim 6, wherein, The circuit breaker further includes: A power supply circuit, the input end of the power supply circuit is used to connect the power grid, the output end of the power supply circuit is connected with the power supply end of the MCU control chip, and the power supply circuit is used to convert and output the output power of the power grid to the MCU control chip; when the power output by the power supply circuit reaches the preset voltage value, the MCU control chip stops receiving the power output by the power supply rapid starting circuit.

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