A solid-state circuit breaker and its control method

Abstract

A solid-state circuit breaker and its control method, comprising a mechanical switch, a power electronic device and a control circuit; the mechanical switch can be triggered manually or electrically, the mechanical switch includes a contact mechanism and a control coil, the contact mechanism includes a main contact and an auxiliary contact, the main contact and the power electronic device are connected in series on the main circuit of the circuit breaker to control the on and off of the main circuit of the circuit breaker, the control circuit is connected to the auxiliary contact to detect the state of the auxiliary contact, the control circuit is connected to the power electronic device to drive the power electronic device to act, and the control circuit can drive the contact mechanism to act through the control coil. When the control circuit is normally powered, the mechanical switch can be triggered manually or electrically, so that the contact mechanism and the power electronic device act to operate the on and off of the main circuit. When the power supply of the control circuit is interrupted, the mechanical switch can only be triggered manually. When the power supply of the control circuit is interrupted, the mechanical switch can still be triggered manually, overcoming the defect that the existing solid-state circuit breaker cannot be closed after power failure.

Description

Technical Field

[0001] The present invention relates to a circuit breaker, and more particularly to a solid-state circuit breaker and its control method. Background Art

[0002] Solid-state circuit breakers are increasingly widely used in flexible AC transmission systems due to their fast switching, reliability, and repeatability, and greatly improve the stability and reliability of power systems when used in conjunction with other devices. However, existing solid-state circuit breakers cannot completely dispense with mechanical switches. Usually, a mechanical switch is installed in a solid-state circuit breaker for electrical isolation. By disconnecting the mechanical switch, leakage current generated by power electronic devices can be avoided. This type of circuit usually controls the switching on and off of the mechanical switch and power electronic devices through time offset. However, since the operation process of the mechanical switch is relatively complex, it usually cannot operate as precisely as power electronic devices. Moreover, the closing and opening of the mechanical switch are controlled by the electronic circuit in the solid-state circuit breaker. When the system is powered off and then needs to be switched on, the solid-state circuit breaker cannot be operated, which has limitations in use. Summary of the Invention

[0003] The object of the present invention is to overcome the defects of the prior art and provide a solid-state circuit breaker and its control method that can overcome the existing operation defects.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A solid-state circuit breaker includes a mechanical switch, power electronic devices, and a control circuit; the mechanical switch can be manually triggered or electrically triggered. The mechanical switch includes a contact mechanism and a control coil that can drive the contact mechanism to act. The contact mechanism includes a main contact and an auxiliary contact. The main contact and the power electronic devices are connected in series on the main circuit of the circuit breaker to control the on and off of the main circuit of the circuit breaker. The control circuit is connected to the auxiliary contact to detect the state of the auxiliary contact, and the control circuit is connected to the power electronic devices to drive the power electronic devices to act. The control circuit can drive the contact mechanism to act through the control coil.

[0006] Preferably, when the mechanical switch is manually or electrically triggered to close, the main contact closes before the auxiliary contact; when the mechanical switch is manually or electrically triggered to open, the auxiliary contact opens before the main contact.

[0007] Preferably, the main contact, the auxiliary contact, and the control coil are assembled together. The total stroke of the main contact and the auxiliary contact is the same. The opening distance of the main contact is less than the opening distance of the auxiliary contact, and the overtravel of the main contact is greater than the overtravel of the auxiliary contact.

[0008] Preferably, when the mechanical switch is manually triggered to close, the main contact closes before the auxiliary contact, and the control circuit detects the closing of the auxiliary contact and then controls the conduction of the power electronic device; when the mechanical switch is manually triggered to open, the auxiliary contact opens before the main contact, and the control circuit detects the opening of the auxiliary contact and then controls the power electronic device to turn off before the main contact opens.

[0009] Preferably, the control circuit obtains power from the power supply system of the circuit breaker, and the mechanical switch is of a magnetic latching structure or a self-latching structure.

[0010] Preferably, the control circuit has a power supply, and the mechanical switch is of an electrically latched structure.

[0011] A control method for a solid-state circuit breaker includes the solid-state circuit breaker as described above:

[0012] When the control circuit is normally powered, the contact mechanism of the mechanical switch in the solid-state relay can be manually triggered. After the control circuit detects the state of the auxiliary contact, the control circuit drives the power electronic device to act according to the state of the auxiliary contact to make the main circuit of the circuit breaker conduct or disconnect;

[0013] When the control circuit is normally powered, the contact mechanism of the mechanical switch can be electrically triggered. When the control circuit receives an automatic control signal, the control circuit drives the power electronic device and the mechanical switch to act step by step to control the on-off of the main circuit of the circuit breaker;

[0014] When the control circuit is powered off, the contact mechanism of the mechanical switch can only be manually triggered and cannot be electrically triggered, and the control circuit cannot conduct the power electronic device.

[0015] Furthermore, when manually or electrically triggering the contact mechanism of the mechanical switch to close, the contact mechanism acts synchronously, and the main contact closes before the auxiliary contact;

[0016] When manually or electrically triggering the contact mechanism of the mechanical switch to open, the contact mechanism acts synchronously, and the auxiliary contact opens before the main contact.

[0017] Furthermore, when the control circuit is normally powered and manually triggering the contact mechanism of the mechanical switch to close, the main contact closes before the auxiliary contact, and after the control circuit detects that the auxiliary contact is in the closed state, it drives the power electronic device to conduct;

[0018] When the control circuit is normally powered and manually triggering the contact mechanism of the mechanical switch to open, the auxiliary contact opens before the main contact, and after the control circuit detects that the auxiliary contact is in the open state, it drives the power electronic device to turn off before the main contact opens.

[0019] Furthermore, when electrically triggering the contact mechanism of the mechanical switch to close or open, the main contact and the auxiliary contact act synchronously under the drive of the control coil.

[0020] Furthermore, when the control circuit is normally powered and obtains an automatic control signal for opening the circuit, the control circuit first drives the power electronic device to turn off, and then drives the control coil to disconnect the contact mechanism;

[0021] When the control circuit is normally powered and obtains an automatic control signal for closing the circuit, the control circuit first drives the control coil to close the contact mechanism, and then the control circuit drives the power electronic device to conduct.

[0022] Furthermore, when the power supply of the control circuit is interrupted and the contact mechanism of the mechanical switch is not manually triggered to act, after the power supply of the control circuit resumes normal power supply, the control circuit detects the state of the auxiliary contact and drives the power electronic device according to the state of the auxiliary contact. When the control circuit detects that the auxiliary contact is in the closed state, the control circuit drives the power electronic device to conduct; when the control circuit detects that the auxiliary contact is in the open state, the control circuit does not drive the power electronic device to conduct.

[0023] Furthermore, when the power supply of the control circuit is interrupted, the contact mechanism of the mechanical switch can remain in the closed state. After the control circuit resumes normal power supply, the control circuit detects the state of the auxiliary contact and drives the power electronic device to act according to the state of the auxiliary contact.

[0024] Furthermore, when the power supply of the control circuit is interrupted and the mechanical switch is already in the open state, the mechanical switch can be manually triggered to close and the contact mechanism can be kept in the closed state. After the control circuit resumes normal power supply, the control circuit drives the power electronic device to conduct after detecting that the auxiliary contact is in the closed state.

[0025] A solid-state circuit breaker and its control method according to the present invention set a mechanical switch that can be manually or electrically triggered in the solid-state circuit breaker. When the power supply of the control circuit of the solid-state circuit breaker is interrupted, the mechanical switch can be manually triggered to achieve the opening and closing of the mechanical switch, and the mechanical switch can still be normally driven after the control circuit resumes power supply, overcoming the defect that the existing solid-state circuit breaker cannot close after power failure.

[0026] In addition, compared with the existing solid-state circuit breaker that is turned off through a mechanical structure, when the auxiliary contact is disconnected and the main contact is not completely disconnected in the present invention, the main circuit is turned off by driving the power electronic device to disconnect, which has the advantages of fast turning-off speed and sensitive response.

[0027] In addition, the control circuit in the solid-state circuit breaker can directly obtain power from the power supply system of the circuit breaker or can also have its own power supply, and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic diagram of a solid-state circuit breaker according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The following is combined with Figure 1 The following embodiments further illustrate the specific implementation of a solid-state circuit breaker and a control method thereof according to the present invention. The solid-state circuit breaker and a control method thereof according to the present invention are not limited to the description of the following embodiments.

[0030] A solid-state circuit breaker includes a mechanical switch, a power electronic device, and a control circuit. The mechanical switch can be triggered manually or electrically. The mechanical switch includes a contact mechanism and a control coil capable of driving the contact mechanism. The contact mechanism includes a main contact and an auxiliary contact. The main contact is connected in series with the power electronic device to control the on / off state of the circuit breaker main circuit. The control circuit is connected to the auxiliary contact to detect the state of the auxiliary contact. The control circuit is connected to the power electronic device to drive the power electronic device to operate. The control circuit can drive the contact mechanism to operate via the control coil.

[0031] When the control circuit is powered normally, the contact mechanism of the mechanical switch in the solid-state relay can be manually triggered. After the control circuit detects the state of the auxiliary contact, the control circuit drives only the power electronic device to operate so that the main line of the circuit breaker is turned on, or drives the power electronic device and the control coil in steps, so that the power electronic device and the contact mechanism operate in steps to disconnect the main line of the circuit breaker.

[0032] When the control circuit is powered normally, the contact mechanism of the mechanical switch can be electrically triggered. When the control circuit receives an automatic control signal, the control circuit drives the power electronic device and the control coil in steps according to the control signal, causing the power electronic device and the contact mechanism to operate in steps to control the on and off of the main line of the circuit breaker.

[0033] When the control circuit is powered off, the contact mechanism of the mechanical switch can only be triggered manually and cannot be triggered electrically, and the control circuit cannot turn on the power electronic device.

[0034] A solid-state circuit breaker and a control method thereof of the present invention are provided with a mechanical switch that can be triggered manually or electrically in the solid-state circuit breaker. When the power supply to the control circuit of the solid-state circuit breaker is interrupted, the mechanical switch can be manually triggered to open and close the mechanical switch. After the power supply to the control circuit is restored, the mechanical switch can still be driven normally, overcoming the defect of existing solid-state circuit breakers that they cannot be closed after power failure.

[0035] Combine Figure 1 A solid-state circuit breaker and a control method thereof are described in detail. A solid-state circuit breaker includes a mechanical switch, a power electronic device and a control circuit; the mechanical switch can be manually triggered (see Figure 1Manual trigger point A) or electric trigger of the mechanical switch. The mechanical switch includes a contact mechanism and a control coil that can drive the contact mechanism. The contact mechanism includes a main contact and at least one auxiliary contact. The main contact and the auxiliary contact act synchronously. The main contact and the power electronic device are connected in series on the main circuit of the circuit breaker to control the on and off of the main circuit of the circuit breaker. The control circuit is connected to an auxiliary contact. The control circuit judges the action of the main contact by detecting the state of the auxiliary contact. The control circuit is connected to the power electronic device. The control circuit judges the state of the main contact by detecting the state of the auxiliary contact. By judging the action intention of the main contact, a control signal is output to control the action of the power electronic device. The control circuit drives the contact mechanism to act through the control coil to achieve the electric trigger of the mechanical switch. In this embodiment, the control circuit has a signal processing function. After receiving and processing the signal, the control circuit outputs a corresponding level signal to drive the opening and closing actions of the power electronic device.

[0036] In this embodiment, when the mechanical switch is manually or electrically triggered to close, the main contact closes before the auxiliary contact; when the mechanical switch is manually or electrically triggered to open, the auxiliary contact opens before the main contact. Especially when the mechanical switch is manually triggered to close, the main contact closes before the auxiliary contact, and the control circuit controls the power electronic device to conduct after detecting the closing of the auxiliary contact; when the mechanical switch is manually triggered to open, the auxiliary contact opens before the main contact, and the control circuit controls the power electronic device to turn off before the main contact disconnects after detecting the disconnection of the auxiliary contact.

[0037] Preferably, the main contact, the auxiliary contact, and the driving coil can be in the same device. When closing, the main contact closes earlier than the auxiliary contact, and when opening, the main contact opens later than the auxiliary contact. Thus, when the control circuit detects the closing of the auxiliary contact, the main contact must be in the closed state. When the control circuit detects that the auxiliary contact is in the open state, the main contact must be in the process of opening. At this time, the control circuit drives the power electronic device to turn off. Since the power electronic device is faster than the mechanical structure, the power electronic device can quickly turn off the main circuit. Compared with the existing solid-state circuit breaker that uses the action of the mechanical switch to turn off the main circuit, the turn-off speed of this application is significantly faster.

[0038] An embodiment of a contact mechanism is provided. Under the condition that the total stroke of the main contact and the auxiliary contact is the same, the opening distance of the main contact is smaller than that of the auxiliary contact, and the overtravel of the main contact is greater than that of the auxiliary contact. In this way, when the contact mechanism operates synchronously, the main contact closes before the auxiliary contact, and the auxiliary contact disconnects earlier than the main contact. For example, the main contact and the auxiliary contact are synchronously triggered. The opening distance of the main contact when contacting is 1 mm, the overtravel is 2 mm, and the total stroke is 3 mm. The contact opening distance of the auxiliary contact is 2 mm, the overtravel is 1 mm, and the total stroke is 3 mm. During the closing process, when the main contact moves to 1 mm, the main contact closes. At this time, the auxiliary contact also moves 1 mm, but the auxiliary contact has not closed yet. When the main contact and the auxiliary contact both move to the position of 2.1 mm - 3 mm, the main contact and the auxiliary contact are both closed, and the closing action is completed at this time; the auxiliary contact closes, and the main contact also closes, and the closing action is completed at this time; during the disconnection process, when the return distances of the main contact and the auxiliary contact are between 1.1 - 1.9 mm, the auxiliary contact has already disconnected, and at this time the main contact is in the closed state. When the return distances of the main contact and the auxiliary contact are at 2.1 mm - 3 mm, the main contact and the auxiliary contact are both in the disconnected state. It should be noted that the opening distance, overtravel and total stroke of the above main contact and auxiliary contact are only for illustrative purposes and are not actual data.

[0039] When the control circuit is normally powered, the contact mechanism of the mechanical switch in the solid-state relay can be manually triggered. The control circuit detects the state of the auxiliary contact, and makes the control circuit judge the action state of the main contact according to the state of the auxiliary contact and issue a control command. When manually triggering the mechanical switch to close, the main contact and the auxiliary contact of the contact mechanism start to close simultaneously. The main contact closes earlier than the auxiliary contact. The electrical signal after the auxiliary contact closes is transmitted to the control circuit, and the control circuit drives the power electronic device to conduct, and the manual closing action is completed; when manually triggering the mechanical switch to disconnect, the main contact and the auxiliary contact of the contact mechanism start to disconnect simultaneously. The auxiliary contact disconnects earlier than the main contact. The electrical signal after the auxiliary contact disconnects is transmitted to the control circuit, and the control circuit drives the power electronic device to disconnect. At this time, the main contact has not been completely disconnected. The reason why the power electronic device disconnects earlier than the main contact is that the speed of the power electronic device is faster than that of the mechanical structure. Finally, the main contact disconnects, and the manual disconnection operation is completed.

[0040] When the control circuit is normally powered, the contact mechanism of the mechanical switch can be electrically triggered. When the control circuit receives an automatic control signal, the control circuit drives the power electronic device and the mechanical switch to act step by step according to the control signal to control the on and off of the main circuit of the circuit breaker. When electrically triggering the contact mechanism of the mechanical switch to close or disconnect, the contact mechanism is synchronously driven by the control coil. But when closing, the main contact closes earlier than the auxiliary contact, and when opening, the auxiliary contact disconnects earlier than the main contact. It should be noted that the control circuit needs to be programmed. Only when the input voltage is normal and an automatic closing control signal is received, can the control circuit drive the mechanical switch to close.

[0041] The specific process is as follows. When the control circuit is normally powered, when the control circuit obtains an automatic control signal to trip, for example, when the control circuit receives a control signal from an overload protection mechanism or a short-circuit protection mechanism and needs to trip the solid-state circuit breaker, the control circuit first drives the power electronic device to turn off, and then drives the control coil to disconnect the contact mechanism; when the control circuit is normally powered again and the control circuit obtains an automatic control signal to close, the control circuit first drives the control coil to close the contact mechanism, that is, the main contact closes before the auxiliary contact. After the auxiliary contact closes, it feeds back to the control circuit that it is in the closed state. After the control circuit detects that the auxiliary contact is in the closed state, it drives the power electronic device to conduct.

[0042] When the control circuit is powered off, the contact mechanism of the mechanical switch can only be manually triggered and cannot be electrically triggered, and the control circuit cannot conduct the power electronic device, and at this time the power electronic device is already in a state where it cannot conduct.

[0043] An improvement point of this application is that the mechanical switch has a manual trigger function. Whether the control circuit is normally powered or not, the mechanical switch can be manually triggered. In this way, it can still be controlled by the control circuit after the power supply is restored, overcoming the defect that the existing solid-state circuit breaker relies only on electronic circuit control, and the operation is convenient.

[0044] Furthermore, when the power supply of the control circuit is interrupted during power supply and the contact mechanism of the mechanical switch is not manually triggered to act, after the power supply of the control circuit resumes normal power supply, the control circuit detects the state of the auxiliary contact and drives the power electronic device according to the state of the auxiliary contact. When the control circuit detects that the auxiliary contact is in the closed state, the control circuit drives the power electronic device to conduct. When the control circuit detects that the auxiliary contact is in the open state, the control circuit does not drive the power electronic device to conduct.

[0045] In the actual application process, when the power supply of the control circuit is interrupted, the contact mechanism of the mechanical switch can be in the closed state or in the open state.

[0046] When the mechanical switch is in the closed state, when it is not manually triggered, the contact mechanism of the mechanical switch can continue to maintain the closed state. After the control circuit resumes normal power supply again, the control circuit drives the power electronic device to conduct after detecting that the auxiliary contact is in the closed state; when the mechanical switch is in the closed state, the auxiliary contact of the mechanical switch is manually triggered to disconnect. When the control circuit detects that the auxiliary contact is in the open state, the control circuit does not drive the power electronic device to conduct. Of course, in this embodiment, it is preferably that when the power supply of the control circuit is interrupted, the mechanical switch can remain in the closed state of the most recent time. After the power supply of the control circuit is restored, the control circuit drives the power electronic device to conduct after detecting that the auxiliary contact is in the closed state.

[0047] When the mechanical switch is in the open state, the contact mechanism can be manually triggered to close and remain closed. After the control circuit resumes normal power supply, the control circuit detects that the auxiliary contact is in the closed state and then drives the power electronic device to conduct; when the mechanical switch is in the open state and the contact mechanism is not closed by manually triggering the mechanical switch, after the control circuit resumes normal power supply, the control circuit does not drive the power electronic device to conduct.

[0048] In this embodiment, the power supply mode of the control circuit is diverse, which is beneficial for application in different scenarios. Preferably, the control circuit can directly obtain power from the power supply system of the solid-state circuit breaker. At this time, the mechanical switch is preferably a magnetic holding structure or a self-holding structure. Of course, the control circuit can also be equipped with its own power supply. At this time, the mechanical switch is preferably an electric holding structure. However, the self-equipped power supply has a limited lifespan and needs to be replaced regularly, which is not as good as directly obtaining power from the power supply system.

[0049] The above content is a further detailed description of the present invention in combination with specific preferred embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention pertains, without departing from the concept of the present invention, several simple deductions or substitutions can be made, and all should be regarded as belonging to the protection scope of the present invention.

Claims

1. A solid-state circuit breaker, characterized in that: It includes a mechanical switch, a power electronic device and a control circuit; the mechanical switch can be triggered manually or electrically, the mechanical switch includes a contact mechanism and a control coil that can drive the contact mechanism to operate, the contact mechanism includes a main contact and an auxiliary contact, the main contact and the power electronic device are connected in series on the main line of the circuit breaker to control the on and off of the main line of the circuit breaker, the control circuit is connected to the auxiliary contact to detect the state of the auxiliary contact, the control circuit is connected to the power electronic device to drive the power electronic device to operate, and the control circuit can drive the contact mechanism to operate through the control coil.

2. The solid-state circuit breaker according to claim 1, wherein: When the mechanical switch is manually or electrically triggered to close, the main contacts close before the auxiliary contacts; when the mechanical switch is manually or electrically triggered to open, the auxiliary contacts open before the main contacts.

3. The solid-state circuit breaker according to claim 2, wherein: The main contact, auxiliary contact and control coil are assembled together, the total stroke of the main contact and the auxiliary contact are the same, the opening distance of the main contact is smaller than the opening distance of the auxiliary contact, and the overtravel of the main contact is greater than the overtravel of the auxiliary contact.

4. The solid-state circuit breaker according to claim 1, wherein: When the mechanical switch is manually triggered to close, the main contact closes before the auxiliary contact. The control circuit detects that the auxiliary contact is closed and then controls the power electronic device to turn on. When the mechanical switch is manually triggered to open, the auxiliary contact opens before the main contact. The control circuit detects that the auxiliary contact is opened and then controls the power electronic device to turn off before the main contact is opened.

5. The solid-state circuit breaker according to claim 1, wherein: The control circuit draws power from the power supply system of the circuit breaker, and the mechanical switch is a magnetic holding structure or a self-holding structure.

6. The solid-state circuit breaker according to claim 1, wherein: The control circuit has a power supply, and the mechanical switch is an electrical holding structure.

7. A control method for a solid-state circuit breaker, characterized in that: Comprising a solid-state circuit breaker according to any one of claims 1 to 5: When the control circuit is powered normally, the contact mechanism of the mechanical switch in the solid-state circuit breaker can be manually triggered. After the control circuit detects the state of the auxiliary contact, the control circuit drives the power electronic device to operate according to the state of the auxiliary contact to connect or disconnect the main line of the circuit breaker; Alternatively, when the control circuit is powered normally, the contact mechanism of the mechanical switch can be electrically triggered. When the control circuit receives an automatic control signal, the control circuit drives the power electronic device and the mechanical switch step by step according to the control signal to control the on and off of the main line of the circuit breaker. When the control circuit is powered off, the contact mechanism of the mechanical switch can only be triggered manually and cannot be triggered electrically, and the control circuit cannot turn on the power electronic device.

8. The control method of a solid-state circuit breaker according to claim 7, wherein: When the contact mechanism of the mechanical switch is closed by manual or electric triggering, the contact mechanism moves synchronously, and the main contact closes before the auxiliary contact; When the contact mechanism of the mechanical switch is manually or electrically triggered to disconnect, the contact mechanism acts synchronously and the auxiliary contact disconnects before the main contact.

9. The control method of a solid-state circuit breaker according to claim 7, wherein: When the control circuit is powered normally, the contact mechanism of the mechanical switch is manually triggered to close, the main contact closes before the auxiliary contact, and the power electronic device is driven to conduct after the control circuit detects that the auxiliary contact is in the closed state; When the control circuit is powered normally, the contact mechanism of the manually triggered mechanical switch is disconnected, and the auxiliary contact is disconnected before the main contact. After the control circuit detects that the auxiliary contact is in the disconnected state, it drives the power electronic device to close before the main contact is disconnected.

10. The control method of a solid-state circuit breaker according to claim 7, wherein: When the contact mechanism of the electrically triggered mechanical switch is closed or opened, the main contacts and auxiliary contacts move synchronously under the drive of the control coil.

11. The control method of a solid-state circuit breaker according to claim 10, characterized in that: When the control circuit is normally powered, when the control circuit obtains the automatic control signal to open the switch, the control circuit first drives the power electronic device to turn off, and then drives the control coil to open the contact mechanism; When the control circuit is normally powered, when the control circuit obtains the automatic control signal to close the switch, the control circuit first drives the control coil to close the contact mechanism, and then drives the power electronic device to turn on.

12. The control method of a solid-state circuit breaker according to claim 7, wherein: When the power supply of the control circuit is interrupted and the contact mechanism of the mechanical switch is not manually triggered to operate, after the power supply of the control circuit is restored to normal, the control circuit detects the state of the auxiliary contact and drives the power electronic device according to the state of the auxiliary contact. When the control circuit detects that the auxiliary contact is in the closed state, the control circuit drives the power electronic device to turn on; when the control circuit detects that the auxiliary contact is in the open state, the control circuit does not drive the power electronic device to turn on.

13. The control method of a solid-state circuit breaker according to claim 7, wherein: When the power supply of the control circuit is interrupted, the contact mechanism of the mechanical switch can remain in the closed state. After the control circuit resumes normal power supply, the control circuit detects the state of the auxiliary contact and drives the power electronic device to operate according to the state of the auxiliary contact.

14. The control method of a solid-state circuit breaker according to claim 7, wherein: When the power supply of the control circuit is interrupted and the mechanical switch is in the disconnected state, the mechanical switch can be manually triggered to close and the contact mechanism can be kept in the closed state. After the control circuit resumes normal power supply, the control circuit detects that the auxiliary contact is in the closed state and drives the power electronic device to turn on.

Images