Solid state circuit breaker

Abstract

The embodiment of the utility model provides a solid-state circuit breaker. The solid-state circuit breaker comprises a switch unit, a driving circuit, a control unit and a protection circuit. The driving circuit is electrically connected with the switch unit and can be switched between a first state and a second state. When the driving circuit is in the first state, the driving circuit can control the switch unit to be connected or disconnected, and when the driving circuit is in the second state, the driving circuit stops controlling the switch unit. The control unit can continuously send out a first signal after being powered on. The protection circuit is electrically connected with the control unit and the driving circuit, controls the driving circuit to be in a first state when receiving the first signal, and controls the driving circuit to be in a second state when not receiving the first signal. By means of the arrangement, when a program is out of control or a system breaks down, the drive circuit stops controlling the switch unit, the switch unit is switched to the off state, and therefore the safety of the circuit system is improved.

Description

TECHNICAL FIELD

[0001] Embodiments of the present disclosure generally relate to the field of electrical equipment, and in particular, to a solid-state circuit breaker. BACKGROUND

[0002] In the power distribution industry, products are developing towards digitization and intelligence, and their safety is becoming increasingly important. For example, solid-state switch circuit breakers and other power distribution products are also being used more and more widely in the market. In some conventional solid-state switch circuit breakers, a control unit is used to control the on or off of a solid-state switch unit. When the program is out of control or the system fails, the circuit breaker may not be able to accurately control the state of the solid-state switch unit, thereby increasing the risk of the circuit system. CONTENT OF THE UTILITY MODEL

[0003] An object of embodiments of the present disclosure is to provide a solid-state circuit breaker to at least partially solve the above-mentioned problems and other potential problems.

[0004] The present disclosure provides a solid-state circuit breaker. The solid-state circuit breaker comprises: a switch unit; a drive circuit, which is electrically connected to the switch unit and is capable of being switched between a first state and a second state, wherein when the drive circuit is in the first state, the drive circuit is capable of controlling the switch unit to be on or off, and when the drive circuit is in the second state, the drive circuit stops controlling the switch unit; a control unit, which is capable of continuously sending a first signal after being powered on; and a protection circuit, which is electrically connected to the control unit and the drive circuit, and controls the drive circuit to be in the first state when the first signal is received, and controls the drive circuit to be in the second state when the first signal is not received.

[0005] In some embodiments, the protection circuit comprises: a level conversion circuit, which is electrically connected to the control unit and the drive circuit, to convert the first signal into a high-level signal; and a logic conversion circuit, which is electrically connected to the level conversion circuit and the drive circuit, and controls the drive circuit to be in the first state when the high-level signal is received, and controls the drive circuit to be in the second state at least when the high-level signal is not received.

[0006] In some embodiments, the level conversion circuit comprises: a diode; a first capacitor, which is electrically connected between the control unit and an anode of the diode; a second capacitor, one end of which is electrically connected to a cathode of the diode, and the other end of which is electrically connected to a ground terminal of the control unit; a first resistor, one end of which is electrically connected to the cathode of the diode, and the other end of which is electrically connected to the ground terminal of the control unit; and a second resistor, one end of which is electrically connected to the ground terminal of the control unit, and the other end of which is electrically connected to a node between the first capacitor and the anode of the diode.

[0007] In some embodiments, the control unit is electrically connected with the drive circuit to send a control signal to the drive circuit, and the drive circuit controls the switching unit to be on in the case of receiving the control signal.

[0008] In some embodiments, the first signal comprises at least one of a pulse width modulation signal and a fixed frequency pulse signal.

[0009] In some embodiments, the solid state circuit breaker further comprises an under-voltage protection circuit electrically connected with the logic conversion circuit, and the under-voltage protection circuit is capable of generating a second signal in the case of an under-voltage in the circuit to make the logic conversion circuit control the drive circuit to be in the second state at least in the case of receiving the second signal.

[0010] In some embodiments, the solid state circuit breaker further comprises a short-circuit protection circuit electrically connected with the logic conversion circuit, and the short-circuit protection circuit is capable of generating a third signal in the case of a short-circuit in the main circuit to make the logic conversion circuit control the drive circuit to be in the second state at least in the case of receiving the third signal.

[0011] In some embodiments, the solid state circuit breaker further comprises an over-temperature protection circuit electrically connected with the logic conversion circuit, and the over-temperature protection circuit is capable of generating a fourth signal in the case of an over-temperature in the main circuit to make the logic conversion circuit control the drive circuit to be in the second state at least in the case of receiving the fourth signal.

[0012] In some embodiments, the drive circuit comprises an application specific integrated circuit or a circuit connected by a plurality of discrete elements.

[0013] In some embodiments, the switching unit comprises at least one of a metal oxide semiconductor field effect transistor or an insulated gate bipolar transistor.

[0014] In embodiments of the present disclosure, the solid state circuit breaker comprises a switching unit, a drive circuit, a control unit and a protection circuit. The drive circuit is electrically connected with the switching unit and is capable of switching between a first state and a second state. In the case of the drive circuit being in the first state, the drive circuit is capable of controlling the switching unit to be on or off, while in the case of the drive circuit being in the second state, the drive circuit stops controlling the switching unit. The control unit is capable of continuously sending a first signal after power-on. The protection circuit is electrically connected with the control unit and the drive circuit, and the protection circuit controls the drive circuit to be in the first state in the case of receiving the first signal, and controls the drive circuit to be in the second state in the case of not receiving the first signal. With this arrangement, in the case of normal program and system operation, the drive circuit can control the switching unit to be on or off. In the case of program out of control or system failure, the drive circuit stops controlling the switching unit. At this time, the drive circuit cannot send a control signal to the switching unit, and the switching unit switches to an off state, thereby increasing the safety of the circuit system.

[0015] It should be understood that the contents described in this section are not intended to limit the key features or important features of the embodiments of the present disclosure, nor to limit the scope of the present disclosure. Other features of the present disclosure will become apparent through the following description. BRIEF DESCRIPTION OF DRAWINGS

[0016] The above and other features, advantages and aspects of embodiments of the present disclosure will become more apparent by describing in detail some embodiments thereof with reference to the attached drawings in which:

[0017] Figure 1 A circuit block diagram of a solid state circuit breaker according to some embodiments of the present disclosure is shown;

[0018] Figure 2 A circuit schematic diagram of a solid state circuit breaker according to some embodiments of the present disclosure is shown;

[0019] Figure 3 A schematic diagram of a level conversion circuit according to some embodiments of the present disclosure is shown;

[0020] Figure 4 A timing diagram of a first signal according to some embodiments of the present disclosure is shown;

[0021] Figure 5 A timing diagram of a level conversion circuit converting a first signal into a high level signal according to some embodiments of the present disclosure is shown; and

[0022] Figure 6 A timing diagram of a control signal according to some embodiments of the present disclosure is shown.

[0023] BRIEF DESCRIPTION OF DRAWINGS

[0024] 10, a switching unit;

[0025] 20, a driving circuit;

[0026] 30, a control unit;

[0027] 40, a protection circuit; 41, a level conversion circuit; 411, a diode; 412, a first capacitor; 413, a second capacitor; 414, a first resistor; 415, a second resistor; 42, a logic conversion circuit;

[0028] 50, an under-voltage protection circuit;

[0029] 60, a short-circuit protection circuit;

[0030] 70, an over-temperature protection circuit. DETAILED DESCRIPTION

[0031] Preferred embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0032] The term "comprising" and its variations as used herein signify open inclusion, i.e., "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "at least partially based on". The terms "one example embodiment" and "one embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc., may refer to different or the same objects.

[0033] As mentioned above, in some conventional solid-state circuit breakers, the solid-state switching unit is controlled to turn on or off through a control unit. When encountering program malfunction or system failure, the circuit breaker may not be able to accurately control the state of the solid-state switching unit, thereby increasing the risk of the circuit system.

[0034] This disclosure provides a solid-state circuit breaker. The solid-state circuit breaker includes a switching unit, a drive circuit, a control unit, and a protection circuit. The drive circuit is electrically connected to the switching unit and can switch between a first state and a second state. In the first state, the drive circuit can control the switching unit to turn on or off; in the second state, the drive circuit stops controlling the switching unit. The control unit can continuously send a first signal after power-on. The protection circuit is electrically connected to the control unit and the drive circuit. Upon receiving the first signal, the protection circuit controls the drive circuit to be in the first state; otherwise, it controls the drive circuit to be in the second state. With this arrangement, the drive circuit can control the switching unit to turn on or off during normal program and system operation. In the event of program malfunction or system failure, the drive circuit stops controlling the switching unit. At this time, the drive circuit cannot send control signals to the switching unit, and the switching unit switches to the off state, thereby increasing the safety of the circuit system. The following will describe... Figures 1 to 6 The principles of this disclosure will be described in detail below.

[0035] like Figures 1 to 3 As shown, a solid-state circuit breaker can respond to abnormal conditions such as overload or short circuit in a circuit, protecting the safety of electrical equipment and lines by disconnecting the main circuit. In embodiments of this disclosure, the solid-state circuit breaker includes a switching unit 10, a drive circuit 20, a control unit 30, and a protection circuit 40.

[0036] As shown in Figure 1 and Figure 2 The switch unit 10 can be electrically connected with the main circuit on the high-voltage side, thereby controlling the on and off of the main circuit. The drive circuit 20 is electrically connected with the switch unit 10, and can control the switch unit 10, thereby determining whether to allow current to pass through the main circuit in different states. When the drive circuit 20 is in the first state, the drive circuit 20 can control the switch unit 10 to be on or off. When the drive circuit 20 switches to the second state, the drive circuit 20 will stop controlling the switch unit 10. For example, the second state of the drive circuit 20 is a low-level state of grounding. In this state, even if there is an external control signal trying to change the state of the switch unit 10, the drive circuit 20 will not perform the corresponding action.

[0037] As shown in Figure 4 The control unit 30 can continuously send a first signal after power-on. The first signal is used to indicate that the control unit 30 is in good running condition, providing a reference for other components.

[0038] As an example, the first signal can include a pulse width modulation (PWM) signal. In a solid-state circuit breaker, the pulse width modulation signal generated by the control unit 30 can be used to control the behavior of the drive circuit 20. At a fixed frequency, by adjusting the proportion of high-level duration (i.e. duty cycle), different instructions can be conveyed.

[0039] As another example, the first signal can include a fixed frequency pulse signal. The fixed frequency pulse signal repeatedly appears within a certain time interval, and its frequency remains constant.

[0040] It should be understood that in other embodiments, the first signal can also be other types of digital signals, and the present disclosure is not intended to be limited in this regard.

[0041] As shown in Figure 1 and Figure 2 The protection circuit 40 is electrically connected with the control unit 30 and the drive circuit 20. In the case that the protection circuit 40 receives the first signal sent by the control unit 30, the protection circuit 40 can control the drive circuit 20 to remain in the first state, thereby allowing the drive circuit 20 to perform normal control operation on the switch unit 10. In the case of program out of control or system failure, the control unit 30 cannot continuously send the first signal. At this time, the protection circuit 40 will control the drive circuit 20 to enter the second state.

[0042] In this way, during normal operation of the program and system, the protection circuit 40 keeps the driving circuit 20 in the first state due to the continuous sending of the first signal by the control unit 30, and the driving circuit 20 can normally control the switching unit 10 to be turned on or turned off. In the case of program out of control or system failure, the first signal sent by the controller is interrupted, and the protection circuit 40 controls the driving circuit 20 to be in the second state. At this time, even if the control unit 30 sends a control signal to the driving circuit 20, the driving circuit 20 cannot control the switching unit 10 to be turned on. At this time, the switching unit 10 automatically switches to the off state, which can avoid turning on the main loop during program out of control or system failure, thereby improving the safety of the circuit system.

[0043] In some embodiments, as shown in Figure 1 and Figure 2 , the protection circuit 40 includes a level conversion circuit 41 and a logic conversion circuit 42. The level conversion circuit 41 is electrically connected with the control unit 30 and the driving circuit 20.

[0044] As shown in Figure 4 and Figure 5 , the level conversion circuit 41 can convert the first signal from the control unit 30 into a high-level signal suitable for subsequent processing, so as to reach a standard sufficient to trigger the logic conversion circuit 42 to work.

[0045] The logic conversion circuit 42 is electrically connected with the level conversion circuit 41 and the driving circuit 20. After receiving the high-level signal, the logic conversion circuit 42 can perform corresponding operations to determine the state of the driving circuit 20. When the logic conversion circuit 42 detects the presence of the high-level signal, it controls the driving circuit 20 to remain in the first state. In this state, the driving circuit 20 can normally control the switching unit 10, and turn on or turn off the main loop as needed. If the logic conversion circuit 42 fails to receive the high-level signal, it means that an abnormal situation occurs in the program or system, such as program out of control or hardware failure. At this time, the logic conversion circuit 42 controls the driving circuit 20 to enter the second state. In the second state, the driving circuit 20 stops controlling the switching unit 10, preventing unsafe operation caused by external commands to turn on the switching unit 10.

[0046] In some embodiments, as shown in Figure 3 , the level conversion circuit 41 includes a diode 411, a first capacitor 412, a second capacitor 413, a first resistor 414, and a second resistor 415. The first capacitor 412 is electrically connected between the control unit 30 and the anode of the diode 411. The first capacitor 412 is used for filtering and smoothing the input signal from the control unit 30, eliminating possible high-frequency noise to ensure the purity of the signal. When the control unit 30 sends out the first signal, the first capacitor 412 makes the signal more stable.

[0047] One end of the second capacitor 413 is connected to the cathode of the diode 411, and the other end is grounded to the ground terminal of the control unit 30. The second capacitor 413 can filter the output signal after passing through the diode 411 to ensure its stability. In addition, the second capacitor 413 can guide high-frequency interference to the ground to avoid affecting the normal operation of the system.

[0048] One end of the first resistor 414 is electrically connected to the cathode of the diode 411, and the other end is electrically connected to the ground terminal of the control unit 30. The first resistor 414 can function as a current limiting and voltage dividing resistor, which can limit the current flowing through the diode 411, thereby preventing excessive current from damaging the diode 411 or other components.

[0049] One end of the second resistor 415 is grounded, and the other end is connected to the node between the first capacitor 412 and the anode of the diode 411. The second resistor 415 can provide a loop path to allow the first capacitor 412 to charge or discharge, and maintain the voltage level of the node when there is no signal input.

[0050] In the level conversion circuit 41, the diode 411 is used for rectification, two capacitors are responsible for filtering the input signal and the output signal respectively, and two resistors are used for current limiting, voltage dividing and adjusting the static operating point. In this way, the level conversion circuit 41 can improve the reliability and anti-interference performance of the solid-state circuit breaker.

[0051] In some embodiments, as shown in FIG. 1, the control unit 30 is electrically connected to the drive circuit 20. Figure 1 and Figure 2 As shown in FIG. 1, when the solid-state circuit breaker is in the normal operation mode, the control unit 30 can generate and send a control signal to the drive circuit 20. Upon receiving the control signal, the drive circuit 20 can control the switching unit 10 to turn on the main loop. Figure 6

[0052] In some embodiments, as shown in FIG. 1, the solid-state circuit breaker further includes an under-voltage protection circuit 50. The under-voltage protection circuit 50 is electrically connected to the logic conversion circuit 42. In the event of an under-voltage in the main loop, such as power grid fluctuation, power failure or other external factors causing voltage drop, the under-voltage protection circuit 50 will activate the protection mechanism. In some embodiments, the under-voltage protection circuit 50 includes a voltage comparator that can monitor the input voltage and compare it with a pre-set safety threshold. Once the actual voltage is detected to be lower than the safety threshold, the under-voltage protection circuit 50 will generate a second signal. Figure 1

[0053] ​​In the case that the second signal is received by the logic conversion circuit 42, the drive circuit 20 will be switched to the second state. In the second state, the drive circuit 20 stops controlling the switching unit 10, and no longer allows current to pass, thereby cutting off the main circuit.

[0054] In some embodiments, as shown in FIG. 2, the solid-state circuit breaker further comprises a short-circuit protection circuit 60. The short-circuit protection circuit 60 is electrically connected to the logic conversion circuit 42. In the case that a short circuit occurs in the main circuit, the current in the main circuit will increase sharply, exceeding the normal working range. The short-circuit protection circuit 60 will identify the abnormal current change phenomenon, and generate a third signal when it confirms the existence of a short circuit. Figure 1

[0055] In the case that the third signal is received by the logic conversion circuit 42, the drive circuit 20 will be switched to the second state. In the second state, the drive circuit 20 stops sending control instructions to the switching unit 10, and the switching unit 10 will automatically enter a high-impedance or open state, thereby rapidly cutting off the current flow in the main circuit.

[0056] In some embodiments, as shown in FIG. 3, the solid-state circuit breaker further comprises an over-temperature protection circuit 70. The over-temperature protection circuit 70 is electrically connected to the logic conversion circuit 42. When the temperature of the main circuit rises due to overload, environmental temperature rise, or other factors, exceeding the safe range, the temperature sensor built into the over-temperature protection circuit 70 will detect the temperature change, and generate a fourth signal when it confirms that the temperature exceeds the standard. Figure 1 Figure 1

[0057] In the case that the fourth signal is received by the logic conversion circuit 42, the drive circuit 20 will be switched to the second state. In the second state, the drive circuit 20 stops sending control instructions to the switching unit 10, causing the switching unit 10 to automatically enter a high-impedance or open state, thereby cutting off the current flow in the main circuit.

[0058] It should be understood that the logic conversion circuit 42 can be a multi-channel or gate, which can control the state of the drive circuit 20 under different signals.

[0059] In some embodiments, the drive circuit 20 comprises an application-specific integrated circuit. In the solid-state circuit breaker, the application-specific integrated circuit can efficiently process signals from the control unit 30 and control the operation of the switching unit 10. The application-specific integrated circuit not only simplifies the circuit structure, but also reduces the number of external components, thereby improving the reliability and response speed of the system.

[0060] In other embodiments, the drive circuit 20 can comprise a circuit connected by a plurality of discrete components. The discrete components may, for example, include transistors, resistors, capacitors, diodes, etc., which are connected together by a topology to form a complete drive system.​​

[0061] In some embodiments, the switching unit 10 can be a metal oxide semiconductor field effect transistor (MOSFET). In this configuration, the control unit 30 can instruct the driving circuit 20 to operate by generating a specific control signal. The control signal is delivered to the gate of the metal oxide semiconductor field effect transistor, thereby controlling the on or off state between its source and drain. When the metal oxide semiconductor field effect transistor receives sufficient gate voltage, it enters the on state and allows current to flow from the source to the drain, thereby achieving the turn-on of the main circuit. In the case where the gate voltage is insufficient to maintain the conduction channel, the metal oxide semiconductor field effect transistor switches to a high impedance state, which can cut off the main circuit.

[0062] In other embodiments, the switching unit 10 can be an insulated gate bipolar transistor (IGBT). The driving circuit 20 can adjust the voltage applied to the gate of the insulated gate bipolar transistor according to the received instructions, which can determine whether it is turned on or off, thereby controlling the on-off state of the main circuit.

[0063] It should be understood that in other embodiments, the switching unit 10 can also include a time delay switch or a contactor, etc., and the present disclosure is not intended to be limited thereto.

[0064] The above has described various embodiments of the present disclosure, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A solid-state circuit breaker, characterized in that, include: Switching unit (10); A drive circuit (20) is electrically connected to the switch unit (10) and is capable of switching between a first state and a second state, wherein when the drive circuit (20) is in the first state, the drive circuit (20) is capable of controlling the switch unit (10) to turn on or off, and when the drive circuit (20) is in the second state, the drive circuit (20) stops controlling the switch unit (10). Control unit (30), which is capable of continuously emitting a first signal after being powered on; as well as A protection circuit (40) is electrically connected to the control unit (30) and the drive circuit (20). The protection circuit (40) controls the drive circuit (20) to be in the first state when it receives the first signal, and controls the drive circuit (20) to be in the second state when it does not receive the first signal.

2. The solid-state circuit breaker according to claim 1, characterized in that, The protection circuit (40) includes: A level conversion circuit (41), electrically connected to the control unit (30) and the drive circuit (20), converts the first signal into a high-level signal; and A logic conversion circuit (42) is electrically connected to the level conversion circuit (41) and the driving circuit (20). The logic conversion circuit (42) controls the driving circuit (20) to be in the first state when it receives the high-level signal, and controls the driving circuit (20) to be in the second state at least when it does not receive the high-level signal.

3. The solid-state circuit breaker according to claim 2, characterized in that, The level conversion circuit (41) includes: Diode (411); The first capacitor (412) is electrically connected between the control unit (30) and the anode of the diode (411); The second capacitor (413) has one end electrically connected to the cathode of the diode (411) and the other end electrically connected to the ground terminal of the control unit (30). A first resistor (414) has one end electrically connected to the cathode of the diode (411) and the other end electrically connected to the ground terminal of the control unit (30); and The second resistor (415) has one end electrically connected to the ground terminal of the control unit (30), and the other end electrically connected to the node between the first capacitor (412) and the anode of the diode (411).

4. The solid-state circuit breaker according to any one of claims 1 to 3, characterized in that, The control unit (30) is electrically connected to the drive circuit (20) to send a control signal to the drive circuit (20), and the drive circuit (20) controls the switch unit (10) to turn on when it receives the control signal.

5. The solid-state circuit breaker according to any one of claims 1 to 3, characterized in that, The first signal includes at least one of a pulse width modulation signal and a fixed frequency pulse signal.

6. The solid-state circuit breaker according to claim 2 or 3, characterized in that, Also includes: An undervoltage protection circuit (50) is electrically connected to the logic conversion circuit (42). The undervoltage protection circuit (50) is capable of generating a second signal in the event of an undervoltage in the circuit, so that the logic conversion circuit (42) controls the drive circuit (20) to be in the second state at least when it receives the second signal.

7. The solid-state circuit breaker according to claim 2 or 3, characterized in that, Also includes: A short-circuit protection circuit (60) is electrically connected to the logic conversion circuit (42). The short-circuit protection circuit (60) can generate a third signal in the event of a short circuit in the main circuit, so that the logic conversion circuit (42) controls the drive circuit (20) to be in the second state at least when it receives the third signal.

8. The solid-state circuit breaker according to claim 2 or 3, characterized in that, Also includes: An over-temperature protection circuit (70) is electrically connected to the logic conversion circuit (42). The over-temperature protection circuit (70) can generate a fourth signal in the event of an over-temperature in the main circuit, so that the logic conversion circuit (42) controls the drive circuit (20) to be in the second state at least when it receives the fourth signal.

9. The solid-state circuit breaker according to any one of claims 1 to 3, characterized in that, The driving circuit (20) includes a dedicated integrated circuit or a circuit composed of multiple discrete components.

10. The solid-state circuit breaker according to any one of claims 1 to 3, characterized in that, The switching unit (10) includes at least one of a metal-oxide-semiconductor field-effect transistor or an insulated-gate bipolar transistor.

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