Solid state circuit breaker

Abstract

The utility model relates to a solid-state circuit breaker which is characterized by comprising a current detection circuit which is configured to detect a current signal in the circuit and output a detection signal; and the current limiting circuit is connected to the current detection circuit and is configured to generate a first control signal for controlling the turn-off of the solid-state circuit breaker according to the detection signal so as to limit the current in the circuit. The current limiting circuit is configured to trip instantly after the current in the line exceeds a set threshold value, so that the damage of excessive short-circuit current to a solid-state device, namely an MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) can be avoided, and meanwhile, a cable can also be protected. And the MCU microprocessor is configured to process and analyze the detection signal representing the current in the circuit, and give a tripping command to break the circuit when a tripping condition is met.

Description

Technical Field

[0001] This utility model relates to a solid-state circuit breaker. Background Technology

[0002] Unlike traditional circuit breakers, solid-state circuit breakers use power components, such as metal-oxide-semiconductor field-effect transistors (MOSFETs), to control the main circuit's on / off state. Compared to traditional mechanical contacts, MOSFETs have a faster response time (μs), but their ability to withstand fault current is relatively limited. Furthermore, if there is capacitance in the load, a large current may exceed the set threshold at power-on, causing the MOSFET to trip. However, traditional circuit breakers lack main circuit control with current breaking time on the microsecond scale.

[0003] Therefore, solid-state circuit breakers are needed to better limit line current, ensuring that excessive instantaneous current does not exceed the set threshold during power-up, while allowing the load capacitor to charge normally. Furthermore, it is necessary to instantly shut down the MOSFET when fault current may damage it, preventing the fault current from rising too rapidly and damaging the MOSFET. Utility Model Content

[0004] This utility model relates to a solid-state circuit breaker, characterized in that it includes: a current detection circuit configured to detect a current signal in the circuit and output a detection signal; and a current limiting circuit connected to the current detection circuit and configured to generate a first control signal for controlling the turn-off of the solid-state circuit breaker based on the detection signal, so as to limit the current in the circuit.

[0005] In one example, the current limiting circuit includes: a first comparator configured to compare a detection signal with a peak current threshold and output a first comparison signal; and a current limiting AND-OR trigger connected to the first comparator and configured to generate the first control signal based on the first comparison signal.

[0006] In one example, when the peak current of the detected signal is higher than the peak current threshold, the first comparator outputs a high-level first comparison signal, and the current-limiting AND-OR trigger outputs a high-level signal and outputs a first control signal via an inverter to control the solid-state circuit breaker to turn off.

[0007] In one example, the first control signal immediately shuts off the solid-state circuit breaker without any intentional delay.

[0008] In one example, the current-limiting AND-OR trigger is also configured to receive a reset signal from the microprocessor unit (MCU) to unlock.

[0009] In one example, the current detection circuit includes: a resistor shunt configured to generate a voltage signal corresponding to the current signal; and a gain amplifier circuit configured to amplify the voltage signal and output it to a microprocessor unit (MCU) for processing.

[0010] In one example, the solid-state circuit breaker further includes a pre-charging circuit connected to a current detection circuit and configured to generate a second control signal based on the detection signal to control the on and off of the solid-state circuit breaker to perform pre-charging on the load capacitor.

[0011] In one example, the pre-charge circuit includes: a second comparator configured to compare a detection signal with an upper limit value of the charging current and output a second comparison signal; a third comparator configured to compare the detection signal with a lower limit value of the charging current and output a third comparison signal; and a pre-charge AND-OR trigger connected to the second and third comparators and configured to generate the second control signal based on the second and third comparison signals, wherein the third comparison signal serves as a reset signal for the pre-charge AND-OR trigger.

[0012] In one example, when the detected signal is higher than the upper limit of the charging current, the second comparator outputs a high-level second comparison signal, the third comparator outputs a high-level third comparison signal, and the precharge AND-OR trigger outputs a high-level signal and outputs a second control signal controlling the solid-state circuit breaker to turn off via an inverter. When the detected signal is lower than the lower limit of the charging current, the second comparator outputs a low-level second comparison signal, the third comparator outputs a low-level third comparison signal, and the precharge AND-OR trigger outputs a low-level signal and outputs a second control signal controlling the solid-state circuit breaker to turn on via an inverter.

[0013] In one example, the solid-state circuit breaker also includes a microprocessor unit (MCU) connected to a current detection circuit, a pre-charge circuit, and a current limiting circuit, and is configured to perform long-delay protection and / or transient protection on the solid-state circuit breaker based on the detection signal.

[0014] In one example, the MCU is also configured to output a precharge circuit enable signal for enabling / disabling the precharge circuit.

[0015] According to the embodiments of this utility model, the solid-state circuit breaker has a better limiting effect on the line current, which can prevent excessive short-circuit current from affecting the normal operation of the MOSFET, and at the same time, it can also limit the short-circuit current in the line and protect the cable.

[0016] Furthermore, according to the embodiments of this utility model, when a short-circuit current, such as a surge current, occurs in the circuit that is sufficient to damage the MOSFET, the current limiting circuit will operate and instantly turn off the MOSFET, thereby protecting the MOSFET from damage.

[0017] According to an embodiment of this utility model, when the circuit breaker is just closed, the pre-charge function is activated to ensure that the instantaneous current during the power-on process does not exceed the set threshold, and the load capacitor can also be charged normally.

[0018] Furthermore, the circuit breaker protection device according to the present invention can directly control the MOSFET to turn on and off through hardware signals, without the need for software signals from the host or microprocessor unit, thus reducing the delay and speed of MOSFET to turn on and off. Attached Figure Description

[0019] The above and other aspects, features, and advantages of specific embodiments of the present invention will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0020] Figure 1 This is a schematic block diagram illustrating a solid-state circuit breaker according to an embodiment of the present invention;

[0021] Figure 2 This is a view showing a schematic circuit of a current detection circuit according to an embodiment of the present invention;

[0022] Figure 3 This is a view showing a schematic circuit of a current-limiting circuit according to an embodiment of the present invention;

[0023] Figure 4 This is a schematic flowchart illustrating a method for operating a solid-state circuit breaker in current-limiting mode according to an embodiment of the present invention;

[0024] Figure 5 This is a schematic block diagram illustrating a solid-state circuit breaker according to another embodiment of the present invention;

[0025] Figure 6 This is a view showing a schematic circuit of a pre-charging circuit according to an embodiment of the present invention;

[0026] Figure 7 This is a schematic flowchart illustrating a method for operating a solid-state circuit breaker in precharge mode according to an embodiment of the present invention;

[0027] Figure 8 This is a schematic block diagram showing a solid-state circuit breaker according to another embodiment of the present invention; and

[0028] Figure 9 This is a schematic flowchart illustrating the operation method of the circuit breaker protection device according to an embodiment of the present invention. Detailed Implementation

[0029] Before proceeding with the detailed description below, it may be advantageous to define certain words and phrases used throughout this invention. The terms “comprising” and “including” and their derivatives mean, but are not limited to, any of the following. The term “controller” or “control unit” means any device, system, or part thereof that controls at least one operation. Such a controller may be implemented in hardware, or a combination of hardware and software and / or firmware. For example, a controller may include, for instance, an application-specific integrated circuit (ASIC), a general-purpose or special-purpose central processing unit (CPU), a digital signal processor (DSP), and programmable logic devices such as a field-programmable gate array (FPGA). A controller may be manufactured as a single printed circuit board (PCB) or distributed across several interconnected PCBs. A controller may include other processing circuitry; for example, a controller may include two processing circuits such as an FPGA and a CPU interconnected on a PCB. The functionality associated with any particular controller may be centralized or distributed, either local or remote. The phrase “at least one,” when used with a list of items, means that different combinations of one or more of the listed items may be used, and perhaps only one item from the list is required. For example, "at least one of A, B, and C" includes any one of the following combinations: A, B, C, A and B, A and C, B and C, A and B and C. Furthermore, in the description of this utility model, the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance or order. In embodiments of this disclosure, unless otherwise expressly stated, "connection" does not necessarily mean "direct connection" or "direct contact," but only requires electrical connection.

[0030] Definitions of other specific words and phrases are provided throughout this invention. Those skilled in the art will understand that, in many, if not most, cases, such definitions apply to the prior and future use of the words and phrases thus defined.

[0031] The various embodiments of the present invention described below with reference to the accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of the present invention in any way. Those skilled in the art will understand that the principles of the present invention can be implemented in any suitably arranged system or device. In some cases, the actions described in the present invention can be performed in different orders and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific order or sequential sequence shown to achieve the desired result. In certain embodiments, multitasking and parallel processing may be advantageous.

[0032] The text and accompanying drawings are provided by way of example only to aid in understanding the present invention. They should not be construed as limiting the scope of the appended claims in any way. Although certain embodiments and examples have been provided, it will be clear to those skilled in the art, based on the content of the present invention, that changes can be made to the illustrated embodiments and examples without departing from the scope of the present invention.

[0033] Figure 1 This is a schematic block diagram showing a solid-state circuit breaker 100 according to an embodiment of the present invention.

[0034] like Figure 1 As shown, the solid-state circuit breaker 100 according to an embodiment of the present invention may include: a current detection circuit 101, which can be configured to detect the current signal in the circuit and output the detection signal; and a current limiting circuit 102, which is connected to the current detection circuit and configured to generate a first control signal for controlling the turn-off of the solid-state circuit breaker based on the detection signal, so as to limit the current in the circuit.

[0035] According to embodiments of this invention, the solid-state circuit breaker provides better current limiting for the circuit. The current-limiting circuit is configured to trip instantaneously when the current in the circuit exceeds a set threshold, preventing excessive short-circuit current from damaging the solid-state device, i.e., the MOSFET, and also protecting the cables. When a short-circuit current sufficient to damage the MOSFET, such as a surge current, occurs in the circuit, the current-limiting circuit activates, instantly turning off the MOSFET and protecting it from damage. Therefore, according to embodiments of this invention, excessive short-circuit current can be prevented from affecting the normal operation of the MOSFET, and it can also limit the short-circuit current in the circuit, protecting the cables.

[0036] Hereinafter, embodiments of the present invention will be described using MOSFETs as examples of solid-state circuit breakers. However, those skilled in the art will recognize that the present invention is not limited thereto, and any other suitable device may be used as a solid-state circuit breaker.

[0037] Figure 2 This is a view showing a schematic circuit 200 of a current detection circuit according to an embodiment of the present invention.

[0038] like Figure 2 As shown, the schematic circuit 200 of the current detection circuit may include a resistor shunt R9 and a gain amplifier circuit OPAMP.

[0039] The resistor shunt R9 can be configured to generate a voltage signal corresponding to the current signal at the input terminal IN, and the gain amplifier circuit OPAMP can be configured to amplify the voltage signal and output it to the microprocessor unit MCU for processing.

[0040] Specifically, the current in the circuit flows through the resistor shunt R9, generating a voltage signal representing the magnitude of the current. Because the resistance value of the resistor shunt R9 is small, the voltage across it is also small. Therefore, this voltage signal is amplified by the gain amplifier circuit OPAMP and can be provided to the pre-charge circuit and the current limiting circuit, as well as to the MCU.

[0041] Although Figure 2 The gain of the OPAMP circuit shown is 10, but the present invention is not limited to this, and those skilled in the art can use other gain values.

[0042] Figure 3 This is a schematic circuit 300 view showing the current limiting circuit of a solid-state circuit breaker according to an embodiment of the present invention.

[0043] like Figure 3 As shown, the schematic circuit 300 of the current limiting circuit may include: a first comparator Comp1, which can be configured to compare a detection signal with a peak current threshold and output a first comparison signal; and a current limiting AND-OR flip-flop, connected to the first comparator Comp1 and configured to generate a first control signal based on the first comparison signal.

[0044] exist Figure 3 In this configuration, the reset signal Reset of the current-limiting AND-OR flip-flop can be provided by the MCU. Specifically, the MCU can provide a low-level Reset signal to the current-limiting AND-OR flip-flop to release the latch.

[0045] In one example, the peak current threshold can be set to 200A. However, the embodiments of this invention are not limited to this, and those skilled in the art can set any suitable peak current threshold as needed.

[0046] When the peak current of the detected signal is higher than the peak current threshold, the first comparator outputs a high-level first comparison signal, and the current limiting AND-OR trigger outputs a high-level signal and outputs a first control signal for controlling the solid-state circuit breaker to turn off via an inverter.

[0047] The first control signal can immediately shut down the solid-state circuit breaker without any intentional delay.

[0048] Specifically, such as Figure 3As shown, when the peak current of the detection signal from the current detection circuit is higher than the peak current threshold (200A), the first comparator Comp1 outputs a high-level first comparison signal, which serves as one input to the OR gate of the current-limiting AND-OR flip-flop. The output of the OR gate serves as one input to the AND gate of the current-limiting AND-OR flip-flop. The output of the AND gate serves as the output of the current-limiting AND-OR flip-flop and is also fed back as the other input to the OR gate. A reset signal Reset can be provided by the MCU as the other input to the AND gate. Therefore, when the peak current of the detection signal is higher than the peak current threshold (200A), the current-limiting AND-OR flip-flop outputs a high-level signal, which is converted to a low-level signal via the inverter INV1 to control the MOSFET to turn off. In other words, the current-limiting circuit outputs a low-level first control signal to turn off the MOSFET.

[0049] Therefore, when the peak current of the detected signal exceeds the peak current threshold (200A), the first comparator Comp1 outputs a high-level first comparison signal, and this high-level first comparison signal is locked by a current-limiting AND-OR flip-flop. The locked state is not released until the MCU outputs a low-level reset signal Reset, allowing the MOSFET to be turned on again.

[0050] Figure 4 This is a schematic flowchart illustrating a method 400 when a solid-state circuit breaker operates in current-limiting mode according to an embodiment of the present invention.

[0051] like Figure 4 As shown, in step 401 of method 400, it is detected whether the peak current of the detection signal is higher than the peak current threshold (200A). When the peak current of the detection signal is higher than the peak current threshold (200A) (yes in 401), in step 402, the MOSFET is automatically turned off. Otherwise, when the peak current of the detection signal is not higher than the peak current threshold (200A) (no in 401), it continues to monitor whether the detection signal is higher than the peak current threshold (200A).

[0052] Here, the solid-state circuit breaker according to the present invention can directly control the MOSFET to turn on and off through hardware signals, without the need for software signals from the host or microprocessor unit, thus reducing the delay and speed of MOSFET to turn on and off.

[0053] Furthermore, the solid-state circuit breaker 100 according to an embodiment of the present invention may include a pre-charge circuit ( Figure 1 (Not shown), the pre-charging circuit can be connected to the current detection circuit 101 and configured to generate a second control signal based on the detection signal to control the on and off of the solid-state circuit breaker in order to perform pre-charging on the load capacitor.

[0054] Figure 5 This is a schematic block diagram illustrating a solid-state circuit breaker 500 according to another embodiment of the present invention.

[0055] like Figure 5 As shown, the solid-state circuit breaker 500 according to an embodiment of the present invention may include: a current detection circuit 501, which can be configured to detect a current signal in the circuit and output a detection signal; a current limiting circuit 502, connected to the current detection circuit and configured to generate a first control signal for controlling the turn-off of the solid-state circuit breaker based on the detection signal, so as to limit the current in the circuit; and a pre-charging circuit 503, which can be connected to the current detection circuit and configured to generate a second control signal for controlling the turn-on and turn-off of the solid-state circuit breaker based on the detection signal, so as to perform pre-charging on the load capacitor.

[0056] Therefore, according to the present invention, when the circuit breaker is just closed, the pre-charge function is enabled to ensure that the instantaneous current during the power-on process does not exceed the set threshold, and the load capacitor can also be charged normally.

[0057] Figure 5 The current detection circuit 501 and current limiting circuit 502 shown in the figure can be similar in structure and operation to those in the reference. Figures 1 to 4 The current detection circuit 101 and the current limiting circuit 102 described herein will not be repeated here.

[0058] Figure 6 This is a view showing a schematic circuit 600 of a pre-charging circuit according to an embodiment of the present invention.

[0059] like Figure 3 As shown, the schematic circuit 600 of the pre-charge circuit may include: a second comparator Comp2, which can be configured to compare the detection signal with the upper limit value of the charging current and output a second comparison signal; a third comparator Comp3, which is configured to compare the detection signal with the lower limit value of the charging current and output a third comparison signal; and a pre-charge AND-OR trigger, connected to the second comparator and the third comparator, and configured to generate the second control signal based on the second comparison signal and the third comparison signal.

[0060] The second control signal can immediately turn on and / or turn off the solid-state circuit breaker without intentional delay.

[0061] exist Figure 6 In this circuit, the third comparison signal output by the third comparator Comp3 can be used as the reset signal Reset for the precharge AND-OR flip-flop.

[0062] In one example, the upper limit of the charging current can be set to 20A, and the lower limit of the charging current can be set to 4A. However, the embodiments of this invention are not limited to this, and those skilled in the art can set any suitable upper and lower limit of the charging current as needed.

[0063] When the detected signal is higher than the upper limit of the charging current, the second comparator outputs a high-level second comparison signal, the third comparator outputs a high-level third comparison signal, and the precharge AND-OR trigger outputs a high-level signal and outputs a second control signal to control the MOSFET to turn off via an inverter.

[0064] When the detection signal is lower than the lower limit of the charging current, the second comparator outputs a low-level second comparison signal, the third comparator outputs a low-level third comparison signal, and the precharge AND-OR trigger outputs a low-level signal and outputs a second control signal to control the MOSFET to turn on via the inverter.

[0065] Specifically, such as Figure 6 As shown, when the detection signal from the current detection circuit is higher than the upper limit of the charging current (20A), the second comparator Comp2 outputs a high-level second comparison signal, which serves as one input to the OR gate of the precharge AND-OR flip-flop. At the same time, the third comparator Comp3 also outputs a high-level third comparison signal, which serves as one input to the AND gate of the precharge AND-OR flip-flop, and the output of the OR gate serves as the other input to the AND gate. The output of the AND gate serves as the output of the precharge AND-OR flip-flop and is also fed back as the other input to the OR gate. Therefore, when the detection signal is higher than the upper limit of the charging current (20A), the precharge AND-OR flip-flop outputs a high-level signal, which is converted to a low-level signal via the inverter INV2 to control the MOSFET to turn off. In other words, the precharge circuit outputs a low-level second control signal to turn off the MOSFET.

[0066] On the other hand, when the detection signal from the current detection circuit is lower than the lower limit of the charging current (4A), the second comparator Comp2 outputs a low-level second comparison signal, which serves as one input to the OR gate of the precharge AND-OR flip-flop. At this time, the third comparator Comp3 also outputs a low-level third comparison signal, which serves as one input to the AND gate of the precharge AND-OR flip-flop, and the output of the OR gate serves as the other input to the AND gate. The output of the AND gate serves as the output of the precharge AND-OR flip-flop and is also fed back as the other input to the OR gate. Therefore, when the detection signal is lower than the lower limit of the charging current (4A), the precharge AND-OR flip-flop outputs a low-level signal, which is converted to a high-level signal via the inverter INV2 to control the MOSFET to turn on. In other words, the precharge circuit outputs a high-level second control signal to turn on the MOSFET.

[0067] When the detection signal from the current detection circuit is not lower than the lower limit of the charging current (4A) and not higher than the upper limit of the charging current (20A), the pre-charging circuit continuously outputs a high-level second control signal, which indicates that the MOSFET is stably turned on, the load capacitor has been fully charged, and the pre-charging mode can be exited.

[0068] Figure 7 A schematic flowchart of a method 700 for operating a solid-state circuit breaker in precharge mode according to an embodiment of the present invention is shown.

[0069] like Figure 7 As shown, in method 700, at 701, it is detected whether the pre-charge current, i.e., the detection signal as described above, is higher than the upper limit of the charging current (20A). When the pre-charge current is higher than 20A (yes in 701), in 702, the MOSFET is automatically turned off. Otherwise, when the pre-charge current is not higher than 20A (no in 701), in 701, it continues to monitor whether the pre-charge current is higher than the upper limit of the charging current. Then, in 703, it is detected whether the pre-charge current is lower than the lower limit of the charging current (4A). When the pre-charge current is lower than 4A (yes in 703), in 704, the MOSFET is automatically turned on to charge the load capacitor. Otherwise, when the pre-charge current is not lower than 4A (no in 703), in 703, it continues to monitor whether the pre-charge current is lower than the lower limit of the charging current.

[0070] Here, the solid-state circuit breaker according to the present invention can directly control the MOSFET to turn on and off through hardware signals, without the need for software signals from the host or microprocessor unit, thus reducing the delay and speed of MOSFET to turn on and off.

[0071] Although Figure 7 The diagram shows steps 701 to 704 performed sequentially, but those skilled in the art will understand that they can be performed in a different manner. Figure 7 Method 700 may be executed in an order other than that shown, without departing from the teachings of this embodiment of the invention. For example, 701 and 703 may be executed in parallel. Alternatively, 703 and 704 may be executed before 701 and 702.

[0072] Figure 8 This is a schematic block diagram showing a solid-state circuit breaker 800 according to another embodiment of the present invention.

[0073] like Figure 8 As shown, in addition to the current detection circuit, pre-charge circuit, and current limiting circuit, the solid-state circuit breaker 800 may also include a microprocessor unit (MCU), which can be connected to the current detection circuit, pre-charge circuit, and current limiting circuit, and can be configured to perform long-delay protection and / or transient protection on the solid-state circuit breaker based on the detection signal.

[0074] Therefore, the microprocessor (MCU) according to this embodiment of the present invention is configured to process and analyze the detection signal representing the current in the circuit, and to issue a trip command to disconnect the circuit when the tripping conditions are met.

[0075] In one example, the MCU is also configured to output a reset signal for a current-limiting AND-OR flip-flop.

[0076] In one example, the MCU is also configured to output a precharge circuit enable signal for enabling / disabling the precharge circuit.

[0077] In one example, the MCU is also configured to output control signals for turning the MOSFET on and off.

[0078] Unlike the first and second control signals output by the pre-charging circuit and current limiting circuit according to the embodiments of the present invention, which are implemented in hardware, the control signals output by the MCU for turning on and off the MOSFET are implemented in software.

[0079] Figure 9 This is a schematic flowchart illustrating an operation method 900 of a solid-state circuit breaker according to an embodiment of the present invention.

[0080] like Figure 9 As shown, in method 900, at step 901, a closing command is received from a remote or manual source. At step 902, the MCU sends a precharge circuit enable signal PCEN to enable / activate the precharge mode. In one example, the precharge circuit is enabled when PCEN = 0, and disabled when PCEN = 1. However, this embodiment of the invention is not limited to this.

[0081] In step 903, the MCU sets the MOSFET. In step 904, the MCU sends a signal MOSCTRL = 1 to control the MOSFET's conduction. Once the MCU controls the MOSFET to conduct, a pre-charge mode can be enabled to limit the current flowing into the load capacitor. In step 905, after a period of time (e.g., 10ms), the MCU can detect whether the pre-charge is complete in step 906. If the MOSFET is still adjusting the current flowing into the load, the system can determine that a short circuit has occurred (no in step 906) and send a signal MOSCTRL = 0 in step 907 to turn off the MOSFET. Then, in step 908, the MCU sends a signal PCEN = 1 to exit the pre-charge mode, i.e., disable the pre-charge function. In step 909, the MCU can also issue an alarm to inform the operator of a short circuit.

[0082] In 906, if the control signal of the precharge circuit is always high (as is the case in 906), it means that the MOSFET is stably turned on. At this time, in 910, the MCU can send the signal PCEN=1 to exit the precharge mode, that is, turn off the precharge function.

[0083] At this point, the load capacitor is fully charged, the load voltage reaches the predetermined target, the pre-charge function ends, and the system operates in normal mode at step 911. The MCU enters protection mode. In protection mode, the MCU uses the detection signal on the line detected by the current detection circuit through the resistor shunt to perform long-delay protection and / or transient protection. At step 912, if the fault current on the line meets the conditions for long-delay protection and / or transient protection (as it does in step 912), the process proceeds to step 907, where the MCU turns off the MOSFET.

[0084] If the conditions for long delay protection and / or transient protection are not met (No for 912), then hardware protection can be triggered in 913, i.e., the current limiting circuit is triggered to operate.

[0085] In the 913, if a short-circuit current occurs in the circuit that is sufficient to damage the MOSFET (as is the case in the 913), the current limiting circuit will activate, momentarily shutting off the MOSFET via the hardware signal FETCTRL (FETCTRL=1). This protects the MOSFET from damage.

[0086] After the MOSFET is turned off by the current limiting circuit, in 914, the MCU can try to re-close the circuit and wait for a period of time (e.g., 1ms) to determine whether there is a short circuit or surge current in the line, and then return to 902 to enter the pre-charge mode.

[0087] When the current limiting circuit is not triggered in 913 (FETCTRL=0), the process can return to 910, and the MCU continues to operate in normal mode.

[0088] Although Figure 9The diagram shows steps 901 to 914 performed sequentially, but those skilled in the art will understand that they can be performed in a different manner. Figure 9 Method 900 may be performed in an order other than that shown in the diagram, without departing from the teachings of this utility model embodiment.

[0089] Although the present invention has been described with reference to exemplary embodiments, various changes and modifications may be suggested to those skilled in the art. The present invention is intended to cover such changes and modifications that fall within the scope of the appended claims.

[0090] Any description in this invention should not be construed as implying that any particular element, step, or function is an essential element that must be included within the scope of the claims. The scope of the patent subject matter is defined only by the claims.

Claims

1. A solid-state circuit breaker, characterized in that, include: The current detection circuit is configured to detect the current signal in the circuit and output a detection signal; as well as A current-limiting circuit is connected to a current-sensing circuit and is configured to generate a first control signal based on the detection signal to control the shutdown of a solid-state circuit breaker, thereby limiting the current in the circuit.

2. The solid-state circuit breaker according to claim 1, characterized in that, The current limiting circuit includes: A first comparator is configured to compare a detection signal with a peak current threshold and output a first comparison signal; and A current-limiting AND-OR trigger is connected to a first comparator and configured to generate the first control signal based on a first comparison signal.

3. The solid-state circuit breaker according to claim 2, characterized in that, When the peak current of the detected signal is higher than the peak current threshold, the first comparator outputs a high-level first comparison signal, and the current limiting AND-OR trigger outputs a high-level signal and outputs a first control signal for controlling the solid-state circuit breaker to turn off via an inverter.

4. The solid-state circuit breaker according to claim 3, characterized in that, The first control signal immediately shuts off the solid-state circuit breaker without any intentional delay.

5. The solid-state circuit breaker according to claim 2, characterized in that, The current limiting AND-OR trigger is also configured to receive a reset signal from the microprocessor unit (MCU) to unlock.

6. The solid-state circuit breaker according to claim 1, characterized in that, The current detection circuit includes: A resistor shunt is configured to generate a voltage signal corresponding to the current signal; and The gain amplifier circuit is configured to amplify the voltage signal and output it to the microprocessor unit (MCU) for processing.

7. The solid-state circuit breaker according to claim 1, characterized in that, Also includes: The pre-charging circuit is connected to the current detection circuit and is configured to generate a second control signal based on the detection signal to control the on and off of the solid-state circuit breaker in order to perform pre-charging on the load capacitor.

8. The solid-state circuit breaker according to claim 7, characterized in that, The pre-charging circuit includes: The second comparator is configured to compare the detection signal with the upper limit of the charging current and output a second comparison signal; The third comparator is configured to compare the detection signal with the lower limit of the charging current and output a third comparison signal; and A precharge AND-OR trigger, connected to the second and third comparators, is configured to generate the second control signal based on the second and third comparison signals. The third comparison signal serves as the reset signal for the precharge AND-OR flip-flop.

9. The solid-state circuit breaker according to claim 8, characterized in that: When the detected signal exceeds the upper limit of the charging current, the second comparator outputs a high-level second comparison signal, the third comparator outputs a high-level third comparison signal, and the precharge AND-OR trigger outputs a high-level signal, which, via an inverter, outputs a second control signal to control the solid-state circuit breaker to turn off. When the detection signal is lower than the lower limit of the charging current, the second comparator outputs a low-level second comparison signal, the third comparator outputs a low-level third comparison signal, and the precharge AND-OR trigger outputs a low-level signal and outputs a second control signal to control the solid-state circuit breaker to turn on via an inverter.

10. The solid-state circuit breaker according to claim 7, characterized in that, It also includes a microprocessor unit (MCU), connected to the current detection circuit, the precharge circuit, and the current limiting circuit, and is configured to: Based on the detection signal, long-delay protection and / or transient protection are performed on the solid-state circuit breaker.

11. The solid-state circuit breaker according to claim 10, characterized in that, The MCU is also configured to output a precharge circuit enable signal for enabling / disabling the precharge circuit.

Images