Switching control apparatus for hybrid switch circuit, and method

Abstract

The present invention provides a switching control apparatus for a hybrid switch circuit, and a method. The apparatus comprises a sensor for sensing an electronic switch to generate a sensing signal, and a controller for controlling a hybrid switch circuit to perform a device switching operation. When a device closing operation is performed, on the basis of a current sensing result of the sensor for the electronic switch, an isolation contact is first closed and then an arc protection contact is closed; and when a device opening operation is performed, on the basis of the current sensing result of the sensor for the electronic switch, the arc protection contact is first opened and then the isolation contact is opened. Therefore, in the present invention, current switching between an electronic switch and a mechanical switch is determined by sensing a current change in the electronic switch, thereby achieving arc-free closing and opening of a hybrid switch circuit; and the present invention has the advantages of a simple circuit structure and ease of implementation.

Description

Switching control device and method for hybrid switching circuits Technical Field

[0001] This invention relates to the field of switch switching control, and more particularly to a switching control device and method for a hybrid switch circuit. Background Technology

[0002] Under high voltage conditions, switching devices are prone to generating electric arcs during the connection or disconnection process, which can damage electronic components. Therefore, switching devices with arc-extinguishing functions are required. However, in related technologies, hybrid switching devices have poor arc-extinguishing effects during the connection or disconnection process because the electronic switch controller cannot know the on / off state of the mechanical switch and it is difficult to determine the current switching between the mechanical and electronic switches.

[0003] Therefore, how to reliably combine the operating state of mechanical contacts in hybrid switching devices with the logic indication of electronic devices to achieve arc-free closing and opening of mechanical contacts has become a pressing technical problem to be solved. Summary of the Invention

[0004] In view of this, the present invention provides a switching control device and method for a hybrid switching circuit, which controls the switching logic of isolation contacts and arc protection contacts by sensing the signal changes of electronic switches, so as to improve the arc extinguishing effect when the hybrid switching circuit performs switching operations and improve the reliability of the switching device operation.

[0005] According to a first aspect of the present invention, a switching control device for a hybrid switching circuit is provided. The hybrid switching circuit includes an electronic switch, an isolation contact connected in series with the electronic switch, and an arc protection contact connected in parallel with the electronic switch. The switching control device includes: a sensor for sensing current changes of the electronic switch to generate a sensing signal; and a controller for executing a device closing operation corresponding to a device closing command or executing a device disconnection operation corresponding to a device disconnection command.

[0006] The device closing operation includes: closing the isolation contact and the electronic switch; and, based on the sensing signal of the sensor, closing the arc protection contact and opening the electronic switch when it is determined that current is flowing through the electronic switch.

[0007] The device disconnection operation includes: closing the electronic switch and disconnecting the arc protection contact; and disconnecting the electronic switch and the isolation contact based on the sensing signal of the sensor when it is determined that current is flowing through the electronic switch.

[0008] In some embodiments, the device closing operation performed by the controller includes:

[0009] In response to the device closing command, the isolation contact and the electronic switch are closed, wherein the first time point at which the electronic switch begins to perform the closing operation is not earlier than the second time point at which the isolation contact begins to perform the closing operation; based on the sensing signal of the sensor, if it is determined that the current flowing through the electronic switch has decreased from large to small, a first sensing result is obtained that current is flowing through the electronic switch; in response to the first sensing result, the arc protection contact is closed; based on the sensing signal of the sensor, if a falling edge of the sensing signal is detected, a second sensing result is obtained that the arc protection contact is fully closed; in response to the second sensing result, the electronic switch is opened.

[0010] In some embodiments, the device disconnection operation performed by the controller includes:

[0011] In response to the device disconnect command, the electronic switch is closed and the arc protection contact is disconnected, wherein the third time point at which the arc protection contact begins to perform the disconnect operation is not earlier than the fourth time point at which the electronic switch begins to perform the closing operation; based on the sensing signal of the sensor, if it is determined that the current flowing through the electronic switch has increased from small to large, a third sensing result indicating that current is flowing through the electronic switch is obtained; based on the generation time of the third sensing result and a preset delay time, a disconnection start time is determined; in response to the determination result that the current time meets the disconnection start time, the electronic switch and the isolation contact are disconnected, wherein the fifth time point at which the isolation contact begins to perform the disconnect operation is not earlier than the sixth time point at which the electronic switch begins to perform the disconnect operation.

[0012] In some embodiments, the preset delay time is determined based on a given time difference between the isolation contact and the arc protection contact.

[0013] In some embodiments, the switching control device further includes a self-tester;

[0014] The controller is configured to send a self-test command to the self-tester when it receives the device closure command or the device disconnect command, and obtain the self-test result of the self-test command from the self-tester. If the self-test result indicates that the sensor is operating normally, the controller continues to execute the device closure operation corresponding to the device closure command or the device disconnect operation corresponding to the device disconnect command. If the self-test result indicates that the sensor is operating abnormally, the controller stops executing the device closure operation corresponding to the device closure command or the device disconnect operation corresponding to the device disconnect command.

[0015] In some embodiments, the self-test device includes a self-test power supply, a first resistor, a second resistor, and an analysis module; the first resistor is connected in parallel with the sensor to form a sensor parallel resistance; the self-test power supply is connected to a first terminal of the analysis module via the second resistor; the self-test power supply is also connected to a ground terminal via the second resistor and the sensor parallel resistance; the second terminal of the analysis module is connected to the ground terminal; the analysis module is used to analyze the voltage difference between the first terminal and the second terminal; if the voltage difference falls within a given voltage difference range, it sends a self-test result indicating an abnormal operating state of the sensor to the controller.

[0016] In some embodiments, the analysis module includes a rectifier unit, an optocoupler unit, and a semiconductor switch. The given differential voltage range is determined based on the operating voltage range of the optocoupler unit. The rectifier unit includes a first terminal and a second terminal. The rectifier unit, the optocoupler unit, the semiconductor switch, and the controller are connected in sequence. The optocoupler unit is used to send an abnormality detection signal to the semiconductor switch when the differential voltage between the first terminal and the second terminal falls within the operating voltage range of the optocoupler unit. The semiconductor switch sends a level conversion signal from high to low level to the controller based on the abnormality detection signal. The controller obtains a self-test result indicating that the sensor's operating state is abnormal based on the level conversion signal.

[0017] In some embodiments, the controller is configured to obtain a self-test result indicating that the sensor is operating normally if it does not receive a level transition signal from the semiconductor switch within a given self-test period after sending the self-test command to the self-tester.

[0018] In some embodiments, the self-test device further includes: a self-test switch disposed between the self-test power supply and the first resistor, which is to be disconnected in the default state and to be closed to power on the self-test device after receiving the self-test command.

[0019] In some embodiments, the electronic switch includes a semiconductor switch; the sensor includes a current transformer.

[0020] According to a second aspect of the present invention, a switching control method for a hybrid switching circuit is provided, the hybrid switching circuit including an electronic switch, an isolation contact connected in series with the electronic switch, an arc protection contact connected in parallel with the electronic switch, and a sensor connected to the electronic switch, the method comprising:

[0021] The device switching command is identified, and when the device switching command is identified as a device closing command, a device closing operation is performed, including: closing the isolation contact and the electronic switch; sensing the current change of the electronic switch through the sensor; and when it is determined that current is flowing through the electronic switch, closing the arc protection contact and opening the electronic switch; or when the device switching command is identified as a device closing command, a device closing operation is performed, including: closing the electronic switch and opening the arc protection contact; sensing the current change of the electronic switch through the sensor; and when it is determined that current is flowing through the electronic switch, opening the electronic switch and the isolation contact.

[0022] In some embodiments, the device closing operation includes:

[0023] In response to the device closing command, the isolation contact and the electronic switch are closed, wherein the first time point at which the electronic switch begins to perform the closing operation is not earlier than the second time point at which the isolation contact begins to perform the closing operation; based on the sensing signal of the sensor, when it is determined that the current flowing through the electronic switch has decreased from large to small, a first sensing result that current is flowing through the electronic switch is obtained;

[0024] In response to the first sensing result, the arc protection contact is closed; based on the sensing signal of the sensor, a second sensing result is obtained when the falling edge of the sensing signal is detected, indicating that the arc protection contact is completely closed; in response to the second sensing result, the electronic switch is turned off.

[0025] In some embodiments, the device disconnection operation includes:

[0026] In response to the device disconnect command, the electronic switch is closed and the arc protection contact is disconnected, wherein the third time point at which the arc protection contact begins to perform the disconnect operation is not earlier than the fourth time point at which the electronic switch begins to perform the closing operation; based on the sensing signal of the sensor, if it is determined that the current flowing through the electronic switch has increased from small to large, a third sensing result indicating that current is flowing through the electronic switch is obtained; based on the generation time of the third sensing result and a preset delay time, a disconnection start time is determined; in response to the determination result that the current time meets the disconnection start time, the electronic switch and the isolation contact are disconnected, wherein the fifth time point at which the isolation contact begins to perform the disconnect operation is not earlier than the sixth time point at which the electronic switch begins to perform the disconnect operation.

[0027] In some embodiments, the method further includes: executing a self-test procedure for the sensor after receiving the device switching instruction;

[0028] If the self-test result of the self-test program indicates that the sensor is operating normally, the device switching command continues to be executed; if the self-test result indicates that the sensor is operating abnormally, the device switching command is stopped.

[0029] The switching control schemes provided in the various embodiments of the present invention sense the current changes of electronic switches through sensors, and control the switching logic between electronic switches and mechanical switches accordingly, so as to realize arc-free conduction and shutdown of hybrid switching circuits and improve the reliability of equipment operation.

[0030] The switching control scheme provided in the various embodiments of the present invention first connects the isolation contact and then connects the electronic switch when the controller performs the device closing operation. When current is sensed flowing through the electronic switch, the arc protection contact is connected. After the current in the electronic switch is detected to be stable, the electronic switch is disconnected, thereby realizing arc-free connection of the hybrid switching circuit.

[0031] The switching control scheme provided in the various embodiments of the present invention, when the controller performs the device disconnection operation, first turns on the electronic switch and then disconnects the arc protection contact. When current is sensed flowing through the electronic switch, based on the time difference between the action of the arc protection contact and the isolation contact, the electronic switch and the isolation contact are disconnected to achieve arc-free disconnection of the hybrid switching circuit.

[0032] The switching control schemes provided in the various embodiments of the present invention can ensure the reliability of the device switching control design by executing a self-test program of the sensor before the hybrid switching circuit performs the switching operation.

[0033] The switching control schemes provided in the various embodiments of the present invention utilize a rectifier unit to achieve bidirectional detection of current rise and fall, and use an optocoupler unit for isolation to reduce the impact of noise and interference signals on the feedback signal, while also ensuring electrical safety. Attached Figure Description

[0034] Figure 1 is a schematic diagram of the structure of a hybrid switching circuit applicable to the switching control device and method of various embodiments of the present invention.

[0035] Figure 2 is a structural diagram of the switching control device of an exemplary embodiment of the present invention.

[0036] Figure 3 is a structural diagram of a switching control device according to another exemplary embodiment of the present invention.

[0037] Figure 4 is a structural diagram of a switching control device according to another exemplary embodiment of the present invention.

[0038] Figure 5 is a structural diagram of the detector according to an exemplary embodiment of the present invention.

[0039] Figure 6 is a flowchart of a switching control method according to an exemplary embodiment of the present invention.

[0040] Figure 7 is a flowchart of a switching control method according to another exemplary embodiment of the present invention.

[0041] Figures 8A and 8B are schematic diagrams of simulation waveforms generated by the switching control methods of various embodiments of the present invention.

[0042] List of reference numerals in the attached diagram: 600. Switching control method for hybrid switching circuit; 602. Identifying device switching command; 604. Executing device closing operation corresponding to device closing command; 606. Executing device disconnection operation corresponding to device disconnection command; 700. Switching control method for hybrid switching circuit; 702. Obtaining device switching command and executing sensor self-test program; 704. Determining whether the sensor's operating status is normal; if yes, proceed to step 602; otherwise, proceed to step 706. 706, Stop Execution of Equipment Switching Command 100, Hybrid Circuit Switch 300, Switching Control Device 110, Mechanical Switch 402, Self-Test Power Supply 112, Isolation Contact 404, First Resistor 114, Arc Contact 406, Second Resistor 120, Electronic Switch 408, Analysis Module 132, Power Supply Positive C1, First Terminal 134, Power Supply Negative C2, Second Terminal 140, Load 412, Rectifier Unit 200, Switching Control Device 414, Optocoupler Unit 210, Sensor 416, Semiconductor Switch 220, Controller 418, Self-Test Switch 230, Self-Tester 420, Diode Detailed Implementation

[0043] To enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention should fall within the protection scope of the present invention.

[0044] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Where there is no conflict between the embodiments, the following embodiments and features can be combined with each other. The steps in the following method embodiments are for illustrative purposes only and are not intended to limit the present invention.

[0045] Compared with traditional AC transmission networks, DC transmission networks can effectively simplify the power conversion process, improve equipment power density and transmission efficiency, and are the main development direction to adapt to the future large-scale new energy grid construction.

[0046] Because the switching capacity and contact opening speed of traditional mechanical circuit breakers are affected by factors such as contact structure, arc-extinguishing medium characteristics, and operating mechanism performance, they are difficult to meet the requirements of rapid fault interruption in DC transmission and distribution networks. Furthermore, the erosion of contacts by the interrupting arc also affects the circuit breaker's breaking performance and service life. Therefore, to enable DC transmission systems to quickly and effectively interrupt fault currents, the industry has proposed a hybrid DC circuit breaker, which combines the static and dynamic advantages of mechanical switches and electronic switches (semiconductor switches), possessing excellent current-carrying and withstand voltage characteristics and rapid turn-off capability.

[0047] However, in high-voltage applications of DC transmission networks, switching devices are prone to arcing during the connection or disconnection process. In related technologies, hybrid switching devices suffer from poor arc extinguishing during the connection or disconnection process because the electronic switch controller cannot know the on / off state of the mechanical switch, making it difficult to calculate the appropriate switching timing for the electronic switch.

[0048] Based on the above-mentioned technical problems, the embodiments of the present invention provide a switching control scheme suitable for hybrid switching circuits. By sensing the current change of the electronic switch, the switching logic between the electronic switch and the mechanical switch is controlled to achieve arc-free switching of the hybrid switching circuit and improve the reliability of the hybrid switching circuit when performing switching operations.

[0049] To help readers better understand the technical solutions of the various embodiments of the present invention, the main structure of the hybrid switching circuit 100 is briefly described below.

[0050] Referring to Figure 1, the hybrid switching circuit 100 mainly includes a mechanical switch 110 and an electronic switch 120.

[0051] Electronic switch 120 includes semiconductor switches, such as insulated gate bipolar transistors (IGBTs).

[0052] The mechanical switch 110 may include an isolating contact 112 and an arc protection contact 114, wherein the isolating contact 112 is connected in series with the electronic switch 120, and the arc protection contact 114 is connected in parallel with the electronic switch 120.

[0053] The hybrid switching circuit 100 also includes a positive power supply terminal 132 (DC+) and a negative power supply terminal 134 (DC-). An isolation contact 112 can be connected to the positive power supply terminal 132, and an arc protection contact 114 can be connected to the negative power supply terminal 134. However, this is not a limitation. In other embodiments, the isolation contact 112 can be connected to the negative power supply terminal 134, and the arc protection contact 114 can be connected to the positive power supply terminal 132. This invention does not impose any restrictions on this.

[0054] The hybrid switching circuit 100 also includes a load 140. For example, the load 140 may be located between the arc protection contact 114 and the negative power supply 134, but this is not a limitation. The location of the load 140 in the hybrid switching circuit 100 may be adjusted according to the actual usage scenario.

[0055] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0056] 200 Switching control device for hybrid switching circuits

[0057] Figure 2 is a schematic diagram of the structure of a switching control device 200 according to an exemplary embodiment of the present invention. As shown in the figure, the switching control device 200 includes a sensor 210 and a controller 220.

[0058] The sensor 210 can be placed in the circuit of the electronic switch 120 to sense the current change of the electronic switch 120 and generate a corresponding sensing signal.

[0059] In some embodiments, the sensor 210 includes, but is not limited to, a current transformer (CT). The current transformer can sense a corresponding pulse signal when the current flowing through the electronic switch 120 changes.

[0060] The controller 220 is used to execute the device closing operation corresponding to the device closing command or to execute the device disconnection operation corresponding to the device disconnection command.

[0061] In some embodiments, controller 220 may include, but is not limited to, a microcontroller (MCU) or a digital signal processor (DSP).

[0062] In some embodiments, the device closing operation performed by the controller 220 may include: closing the isolation contact 112 and the electronic switch 120, and based on the sensing signal of the sensor 210, closing the arc protection contact 114 and opening the electronic switch 120 when it is determined that current is flowing through the electronic switch 120.

[0063] Specifically, the controller 220 can close the isolation contact 112 and the electronic switch 120 in response to the device closing command. The first time point at which the electronic switch 120 begins to perform the closing operation is no earlier than the second time point at which the isolation contact 112 begins to perform the closing operation. That is, the electronic switch 120 is turned on after the isolation contact 112 is closed.

[0064] The controller 220 can obtain a first sensing result that current is flowing through the electronic switch 120 based on the sensing signal of the sensor 210 and when it is determined that the current in the electronic switch 120 has changed from large to small.

[0065] The controller 220 can close the arc protection contact 114 based on the first sensing result and continue to monitor the sensing signal of the sensor 210. When the falling edge of the sensing signal is detected, the controller 220 can obtain the second sensing result that the arc protection contact 114 is completely closed.

[0066] Specifically, when the electronic switch 120 is turned on, and the arc protection contact 114 connected in parallel with it is also turned on, the current in the electronic switch 120 will rise instantaneously and then slowly decrease and gradually stabilize. When the current flowing through the electronic switch 120 stabilizes, the pulse signal sensed by the current transformer (sensor 210) will also disappear. At this time, the judgment result that the arc protection contact 114 is completely closed can be obtained.

[0067] The controller 220 can disconnect the electronic switch 120 based on the second sensing result, thereby realizing the arc-free closing operation of the hybrid switching circuit 100.

[0068] In some embodiments, the device disconnection operation performed by the controller 220 may include:

[0069] Close the electronic switch 120 and disconnect the arc protection contact 114. Based on the sensing signal of the sensor 210, if it is determined that current is flowing through the electronic switch 120, disconnect the electronic switch 120 and the isolation contact 112.

[0070] Specifically, the controller 220 can respond to the device disconnection command by closing the electronic switch 120 and disconnecting the arc protection contact 114. The third time point at which the arc protection contact 114 begins to perform the disconnection operation is no earlier than the fourth time point at which the electronic switch 120 begins to perform the closing operation. That is, the arc protection contact 114 is disconnected after the electronic switch 120 is turned on.

[0071] The controller 220 can obtain a third sensing result that current is flowing through the electronic switch 120 based on the sensing signal of the sensor 210 when it is determined that the current in the electronic switch 120 is increasing from small to large.

[0072] The controller 220 can determine the disconnection start time based on the generation time of the third sensing result and the preset delay time. If it is determined that the current time meets the disconnection start time, the controller 220 disconnects the electronic switch 120 and the isolation contact 112. The fifth time point at which the isolation contact 112 starts to perform the disconnection operation is not earlier than the sixth time point at which the electronic switch 120 starts to perform the disconnection operation, thereby realizing the arc-free disconnection operation of the hybrid switching circuit.

[0073] In this embodiment, the preset delay time is determined based on a given action time difference between the isolation contact 112 and the arc protection contact 114. Generally, the preset delay time should not be less than the given action time difference. Preferably, the preset delay time can be 0.5ms to 1ms longer than the given action time difference. For example, if the given action time difference between the isolation contact 112 and the arc protection contact 114 is 1ms, the preset delay time can be set to between 1.5ms and 2ms.

[0074] In summary, the switching control device of this embodiment accurately determines the current switching between the mechanical contacts and the electronic switch by sensing the current change in the electronic switch, thereby reasonably controlling the conduction and disconnection of the electronic switch, realizing arc-free connection and disconnection of the hybrid switching circuit, and the switching control circuit structure design is simple and easy to implement.

[0075] 300 switching control device for hybrid switching circuits

[0076] Figure 3 is a schematic diagram of the switching control device 300 of another exemplary embodiment of the present invention.

[0077] Referring to Figure 4, in some embodiments, the output pin of sensor 210 can be input to rectifier unit 412 via a common-mode inductor (not shown), a first resistor 404, and a TVS clamping diode (not shown), and then enter optocoupler unit 414 after passing through voltage divider module and filter module (not shown) to transmit the sensing signal of sensor 210 (i.e., the current change signal of electronic switch 120) to controller 220, thereby controlling the on and off of electronic switch 120. Considering the importance of this signal, this embodiment performs a self-test on sensor 210 before controlling the hybrid switching circuit (mechanical switch) to perform the switching operation to ensure the reliability of the subsequent switching control scheme.

[0078] As shown in the figure, the switching control device 300 may include: a sensor 210, a controller 220, and a self-tester 230.

[0079] After receiving a device closing command or a device opening command, the controller 220 sends a self-test command to the self-tester 230 and obtains the self-test result from the self-tester 230. If the self-test result indicates that the sensor 210 is operating normally, the controller continues to execute the device closing operation corresponding to the device closing command or the device opening operation corresponding to the device opening command. If the self-test result indicates that the sensor 210 is operating abnormally, the controller stops executing the device closing operation corresponding to the device closing command or the device opening operation corresponding to the device opening command.

[0080] In some embodiments, the self-test device 230 may include a self-test power supply 402, a first resistor 404, a second resistor 406, an analysis module 408, and a self-test switch 418 (refer to Figures 4 and 5).

[0081] In this embodiment, the first resistor 404 is a load disposed within the sensor 210. In the self-test state, the sensor 210 can be equivalent to a DC resistor (Rdc). By connecting the first resistor 404 in parallel with the sensor 210, a parallel resistor for the sensor is formed. The resistance of the first resistor 404 is much larger than the resistance of the sensor 210. The resistance of the first resistor 404 after being connected in parallel with the sensor 210 (Rdc) is approximately the same as the resistance of the sensor 210 (Rdc).

[0082] In this embodiment, when the sensor 210 is operating normally, the resistance of the second resistor 406 is greater than the resistance of the sensor 210. When the sensor 210 malfunctions (for example, the sensor 210 experiences winding burnout, failure to connect, or other abnormal conditions), the resistance of the sensor 210 is equivalent to the open circuit resistance, and the resistance of the second resistor 406 will be less than the resistance of the sensor 210.

[0083] The self-test power supply 402 can be connected to the first terminal C1 of the analysis module 408 via the second resistor 406. The self-test power supply 402 is also connected to the ground terminal via the second resistor 406 and the parallel resistor of the sensor. The second terminal C2 of the analysis module 408 is connected to the ground terminal. The voltage input from the first terminal C1 can be output through the second terminal C2 and grounded to form a loop.

[0084] The self-test switch 418 can be set between the self-test power supply 402 and the second resistor 406. The self-test switch 418 is in the off state by default and closes after receiving a self-test command to power on the self-tester 230.

[0085] The analysis module 408 is used to analyze the pressure difference between the first terminal C1 and the second terminal C2. If the pressure difference falls within the given pressure difference range, it sends the self-test result of the sensor 210's abnormal operating status to the controller 220.

[0086] In some embodiments, a diode 420 may be provided on the side of the second resistor 406 away from the self-test power supply 402 to provide reverse current protection during periods when the self-test procedure of the sensor 210 is not being performed.

[0087] In some embodiments, the analysis module 408 includes a rectifier unit 412, an optocoupler unit 414, and a semiconductor switch 416, and the given differential voltage range is determined based on the operating voltage range of the optocoupler unit 414.

[0088] The rectifier unit 412 includes a first terminal C1 and a second terminal C2, and the rectifier unit 412, optocoupler unit 414, semiconductor switch 416 and controller 220 are connected in sequence, with the signal output of the previous electronic component serving as the signal input of the next electronic component.

[0089] The optocoupler unit 414 can be used to operate when the voltage difference between the first terminal C1 and the second terminal C2 of the rectifier unit 412 falls within the operating voltage range of the optocoupler unit 414, and send an abnormal detection signal to the semiconductor switch 416. The semiconductor switch 416 can send a level conversion signal from high level to low level to the controller 220 according to the abnormal detection signal. The controller 220 obtains the self-test result of the abnormal operating state of the sensor 210 according to the level conversion signal.

[0090] In some embodiments, a voltage divider resistor (not shown) may be provided between the rectifier unit 412 and the optocoupler unit 414, depending on the input voltage of the sensor 210 and the specific model of the optocoupler unit 414, to ensure that the optocoupler unit 414 can operate normally within the desired voltage range and to ensure normal signal feedback.

[0091] For example, referring to FIG5, after receiving a device closing command or a device opening command, the controller 220 may send a self-test enable signal to the self-tester 230 to close the self-test switch 418. In some embodiments, a digital isolation chip may be used to transmit the self-test enable signal to ensure the security and reliability of signal transmission.

[0092] With the self-test switch 418 closed, the voltage source of the self-test power supply 402 (e.g., P10V) flows into the first terminal C1 of the rectifier unit 412 via the second resistor 406 and the diode 420, and then into the ground terminal via the second resistor 406, the diode 420, and the parallel resistor of the sensor. In this case, the input voltage difference between the first terminal C1 and the second terminal C2 of the rectifier unit 412 can be expressed by the following formula: V C2-C1 =(V 402 -Vce 418 -VF 420 )×(R 210 / / R 404 ) / (R 210 / / R 404 +R 406 )

[0093] In the above formula, V 402 This indicates the voltage drop across the self-test power supply 402, V. 418 This indicates the voltage drop across the self-test switch 418, VF. 420 R represents the voltage drop across diode 420. 210 / / R 404 R represents the voltage drop across the parallel resistor of the sensor. 406 This indicates the voltage drop across the second resistor 406.

[0094] Among them, when the input voltage difference (V) between the first terminal C1 and the second terminal C2 C2-C1 When the voltage falls within the operating voltage range that allows the optocoupler unit 414 to operate normally, it indicates that the sensor 210 is abnormal. The semiconductor switch 416 can feed back a level conversion signal from high level to low level to the controller 220. The controller 220 can obtain the self-test result of the abnormal operating status of the sensor 210 based on this level conversion signal.

[0095] In some embodiments, if the controller 220 does not receive a level conversion signal from the semiconductor switch 416 within a given self-test period after sending a self-test command to the self-tester 230, it obtains a self-test result indicating that the sensor 210 is operating normally.

[0096] In some embodiments, the semiconductor switch 416 may include, but is not limited to, transistors, MOSFETs (metal-oxide-semiconductor field-effect transistors), etc.

[0097] In summary, the switching control device of this embodiment can sense the current change of the electronic switch through a sensor to control the switching logic between the electronic switch and the mechanical switch, realize arc-free conduction and shutdown of the hybrid switching circuit, improve the reliability of equipment operation, and has the advantages of simple and easy-to-implement self-test circuit structure design.

[0098] Furthermore, by performing a self-test procedure on the sensor before executing the switching operation of the hybrid switching circuit, the reliability of the switching control device in controlling the hybrid switching circuit to perform the switching operation can be ensured.

[0099] Furthermore, by incorporating a rectifier unit in the self-test, bidirectional detection of current rise and fall can be achieved. Additionally, by incorporating an optocoupler unit in the self-test, the isolation provided by the optocoupler can reduce the impact of noise and interference signals on the feedback signal, thereby ensuring electrical safety.

[0100] 600 Switching control method for hybrid switching circuits

[0101] Figure 6 shows the processing flow of the switching control method 600 for a hybrid switching circuit according to an exemplary embodiment of the present invention. The hybrid switching circuit 100 includes an electronic switch 120, an isolation contact 112 connected in series with the electronic switch 120, an arc protection contact 114 connected in parallel with the electronic switch 120, and a sensor 210 connected to the electronic switch 120 (refer to the example shown in Figure 2).

[0102] As shown in the figure, the method 600 in this embodiment mainly includes:

[0103] Step 602: Identify the device switching command and select to execute either step 604 or step 606.

[0104] In this embodiment, if the identified device switching command is a device closing command, step 604 is executed; if the identified device switching command is a device disconnection operation, step 606 is executed.

[0105] Step 604: Execute the device closing operation corresponding to the device closing command.

[0106] In some embodiments, the isolation contact 112 and the electronic switch 120 can be closed. By sensing the change in current of the electronic switch 120 through the sensor 231, if it is determined that current is flowing through the electronic switch 120, the arc protection contact 114 can be closed and the electronic switch 120 can be opened.

[0107] Specifically, in response to a device closing command, the isolation contact 112 and the electronic switch 120 can be closed, wherein the first time point at which the electronic switch 120 begins to perform the closing operation is no earlier than the second time point at which the isolation contact 112 begins to perform the closing operation. Based on the sensing signal of the electronic switch 120, it can be determined that the current flowing through the electronic switch 120 has decreased from a large value, and a first sensing result of current flowing through the electronic switch 120 can be obtained. In response to the first sensing result, the arc protection contact 114 can be closed, and the sensing signal of the electronic switch 120 can be acquired. Based on the sensing signal of the electronic switch 120, in the case of detecting a falling edge of the sensing signal, a second sensing result of the arc protection contact 114 being fully closed can be obtained. In response to the second sensing result, the electronic switch 120 can be opened to complete the closing operation of the hybrid switching circuit.

[0108] Step 606: Execute the device disconnection operation corresponding to the device disconnection command.

[0109] In some embodiments, the electronic switch 120 can be closed and the arc protection contact 114 can be disconnected. The current change of the electronic switch 120 can be sensed by the sensor 210. If it is determined that there is current flowing through the electronic switch 120, the electronic switch 120 and the isolation contact 112 can be disconnected.

[0110] Specifically, in response to a device disconnection command, the electronic switch 120 can be closed and the arc protection contact 114 can be disconnected. The third time point at which the arc protection contact 114 begins its disconnection operation is no earlier than the fourth time point at which the electronic switch 120 begins its closing operation. Based on the sensing signal of the electronic switch 120, a third sensing result indicating that current is flowing through the electronic switch 120 can be obtained when it is determined that the current flowing through the electronic switch 120 is increasing. Based on the generation time of the third sensing result and a preset delay time, a disconnection start time can be determined. In response to the determination that the current time meets the disconnection start time, the electronic switch 120 and the isolation contact 112 can be disconnected. The fifth time point at which the isolation contact 112 begins its disconnection operation is no earlier than the sixth time point at which the electronic switch 120 begins its disconnection operation.

[0111] Switching control method for hybrid switching circuits 700

[0112] Figure 7 illustrates the processing flow of a switching control method 700 according to another exemplary embodiment of the present invention. As shown in the figure, the method 700 of this embodiment mainly includes:

[0113] Step 702: Obtain the device switching command and execute the self-test program of sensor 210.

[0114] Step 704: Determine whether the sensor is operating normally. If yes, proceed to step 602; otherwise, proceed to step 706.

[0115] Specifically, if the self-test result of the self-test program indicates that the sensor 210 is operating normally, step 602 is executed to continue executing the device switching command; otherwise, if the self-test result indicates that the sensor 210 is operating abnormally, step 706 is executed.

[0116] Step 706: Stop executing the device switching command.

[0117] Specifically, when the sensor 210 is found to be in an abnormal operating state, the mechanical switch of the hybrid switching circuit can be prevented from performing a switching operation, and a fault warning message can be output.

[0118] Figures 8A and 8B are signal waveform diagrams obtained by implementing the switching control methods of various embodiments of the present invention, which are used to show the current transfer trend between the mechanical switch and the electronic switch through the sensor feedback during the switching process of the hybrid switching circuit.

[0119] Figure 8A is a signal waveform diagram of the device closing operation performed using the switching control method of this embodiment. Waveform 802 represents the voltage detection signal of the rectifier unit 412 for the CT, and waveform 804 represents the voltage detection signal of the semiconductor switch 416.

[0120] As shown in Figure 8A, when semiconductor switch 416 is on, after isolation contact 112 closes, the voltage detection signal of rectifier unit 412 is pulled low (refer to the first trough of waveform 802), and the voltage detection signal of semiconductor switch 416 slowly rises (refer to the upslope of waveform 804); when arc protection contact 114 closes and conducts, current is transferred from electronic switch 120 to arc protection contact 114, and the voltage detection signal of semiconductor switch 416 drops back (refer to the downslope of waveform 804). (The voltage detection signal of the rectifier unit 412 will rise during the trough section). Since the arc protection contact 114 is a mechanical contact, it will rebound after closing. Therefore, the voltage detection signal of the rectifier unit 412 will fall again and the voltage detection signal of the semiconductor switch 416 will rise again (refer to the second uphill section of waveform 804). Until the arc protection contact 114 is fully closed, no current flows through the electronic switch 120. At this time, the voltage detection signal of the semiconductor switch 416 will fall again and tend to stabilize.

[0121] Figure 8B is a signal waveform diagram of the device disconnection operation performed using the switching control method of this embodiment. Waveform 806 represents the voltage detection signal of the rectifier unit 412 for the CT, and waveform 808 represents the voltage detection signal of the semiconductor switch 416.

[0122] As shown in Figure 8B, when the electronic switch 120 is closed and the arc protection contact 114 is open, the current is transferred to the electronic switch 120, and the voltage detection signal of the semiconductor switch 416 will rise (refer to the peak segment of waveform 808); when the electronic switch 120 is opened, since no current flows through the electronic switch 120, the voltage detection signal of the semiconductor switch 416 will fall back and tend to stabilize.

[0123] In summary, the switching control method of this embodiment, by sensing the current change in the electronic switch and controlling the switching logic of the isolation contact and the arc protection contact accordingly, can improve the arc extinguishing effect when the hybrid switching circuit performs switching operations and enhance the operational reliability of the switching device.

[0124] Furthermore, the switching control method of this embodiment ensures the reliability of the switching control scheme by executing a self-test program of the sensor before performing the switching operation, thereby realizing arc-free connection and disconnection of the hybrid switching circuit.

[0125] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0126] Not all steps and modules in the above process and system structure diagrams are mandatory; some steps or modules can be omitted as needed. The execution order of each step is not fixed and can be adjusted as required. The system structure described in the above embodiments can be a physical structure or a logical structure. That is, some modules may be implemented by the same physical entity, or some modules may be implemented by multiple physical entities, or they may be jointly implemented by certain components in multiple independent devices.

[0127] In the above embodiments, the hardware modules can be implemented mechanically or electrically. For example, a hardware module may include permanent dedicated circuitry or logic (such as a dedicated processor, FPGA, or ASIC) to perform the corresponding operations. The hardware module may also include programmable logic or circuitry (such as a general-purpose processor or other programmable processor), which can be temporarily configured by software to perform the corresponding operations. The specific implementation method (mechanical, dedicated permanent circuitry, or temporarily configured circuitry) can be determined based on cost and time considerations.

[0128] The present invention has been shown and described in detail above with reference to the accompanying drawings and preferred embodiments. However, the present invention is not limited to these disclosed embodiments. Based on the above embodiments, those skilled in the art will know that more embodiments of the present invention can be obtained by combining the code review methods in the different embodiments. These embodiments are also within the protection scope of the present invention.

Claims

1. A switching control device (200) for a hybrid switching circuit (100), the hybrid switching circuit (100) comprising an electronic switch (120), an isolating contact (112) in series with the electronic switch (120), an arc protection contact (114) in parallel with the electronic switch (120), wherein, The switching control device (200) comprises: a sensor (210) configured to sense a current change of the electronic switch (120) and generate a sensing signal; a controller (220) configured to perform a device closing operation corresponding to a device closing instruction or perform a device opening operation corresponding to a device opening instruction; wherein the device closing operation comprises: closing the isolation contact (112) and the electronic switch (120), and closing the arc prevention contact (114) and opening the electronic switch (120) according to the sensing signal of the sensor (210) when it is determined that there is current flowing through the electronic switch (120); the device opening operation comprises: closing the electronic switch (120) and opening the arc prevention contact (114), and opening the electronic switch (120) and the isolation contact (112) according to the sensing signal of the sensor (210) when it is determined that the current flowing through the electronic switch (120) changes from small to large.

2. The switching control device (200) according to claim 1, wherein The device closing operation performed by the controller (220) comprises: in response to the device closing instruction, closing the isolation contact (112) and the electronic switch (120), wherein a first time point at which the electronic switch (120) starts to perform the closing operation is not earlier than a second time point at which the isolation contact (112) starts to perform the closing operation; based on the sensing signal of the sensor (210), obtaining a first sensing result that there is current flowing through the electronic switch (120) when it is determined that the current flowing through the electronic switch (120) changes from large to small; in response to the first sensing result, closing the arc prevention contact (114); based on the sensing signal of the sensor (210), obtaining a second sensing result that the arc prevention contact (114) is completely closed when a falling edge of the sensing signal is detected; in response to the second sensing result, opening the electronic switch (120).

3. The switching control device according to claim 1, wherein The device opening operation performed by the controller (220) comprises: in response to the device opening instruction, closing the electronic switch (120) and opening the arc prevention contact (114), wherein a third time point at which the arc prevention contact (114) starts to perform the opening operation is not earlier than a fourth time point at which the electronic switch (120) starts to perform the closing operation; based on the sensing signal of the sensor (210), obtaining a third sensing result that there is current flowing through the electronic switch (120) when it is determined that the current flowing through the electronic switch (120) changes from small to large; determining an opening start time based on a generation time point of the third sensing result and a preset delay time; in response to a determination result that a current time meets the opening start time, opening the electronic switch (120) and the isolation contact (112), wherein a fifth time point at which the isolation contact (112) starts to perform the opening operation is not earlier than a sixth time point at which the electronic switch (120) starts to perform the opening operation.

4. The switching control device according to claim 3, wherein The preset delay time is determined according to a given action time difference between the isolating contact (112) and the arc protection contact (114).

5. The switching control device (300) according to claim 1, wherein, the switching control device further comprises a self-checker (230); the controller (220) is configured to send a self-check instruction to the self-checker (230) and acquire a self-check result of the self-check instruction from the self-checker (230) if the device closing instruction or the device opening instruction is acquired, and continue to execute a device closing operation corresponding to the device closing instruction or execute a device opening operation corresponding to the device opening instruction if the self-check result is that the running state of the sensor (210) is normal, and stop executing the device closing operation corresponding to the device closing instruction or executing the device opening operation corresponding to the device opening instruction if the self-check result is that the running state of the sensor (210) is abnormal.

6. The switching control device (300) according to claim 5, wherein, the self-checker (230) comprises a self-check power supply (402), a first resistor (404), a second resistor (406), and an analysis module (408); the first resistor (404) is connected in parallel with the sensor (210) to form a sensor parallel resistor, the self-check power supply (402) connects a first terminal (C1) of the analysis module (408) via the second resistor (406), and the self-check power supply (402) also connects a ground terminal via the second resistor (406) and the sensor parallel resistor, and a second terminal (C2) of the analysis module (408) is connected to the ground terminal; the analysis module (408) is configured to analyze a pressure difference between the first terminal (C1) and the second terminal (C2), and send a self-check result that the running state of the sensor (210) is abnormal to the controller (220) if the pressure difference falls within a given pressure difference range.

7. The switching control device according to claim 6, wherein, the analysis module (408) comprises a rectifier unit (412), an optical coupling unit (414), and a semiconductor switch (416), and the given pressure difference range is determined based on a working voltage range of the optical coupling unit (414); the rectifier unit (412) comprises the first terminal (C1) and the second terminal (C2), and the rectifier unit (412), the optical coupling unit (414), the semiconductor switch (416), and the controller (220) are connected in sequence. The light coupling unit (414) is configured to send an abnormality detection signal to the semiconductor switch (416) when a voltage difference between the first terminal (C1) and the second terminal (C2) falls within a working voltage range of the light coupling unit (414), and the semiconductor switch (416) is configured to send a level conversion signal from high to low to the controller (220) according to the abnormality detection signal, and the controller (220) is configured to obtain a self-checking result that the operating state of the sensor (210) is normal when no level conversion signal is received from the semiconductor switch (416) within a given self-checking period after the self-checking instruction is sent to the self-checker (230).

8. The switching control device according to claim 7, wherein, The controller (220) is configured to obtain a self-checking result that the operating state of the sensor (210) is normal when no level conversion signal is received from the semiconductor switch (416) within a given self-checking period after the self-checking instruction is sent to the self-checker (230).

9. The switching control device according to claim 6, wherein The self-checker (230) further comprises: A self-checking switch (418) is arranged between the self-checking power supply (402) and the second resistor (406) and is configured to be closed to energize the self-checker (230) after receiving the self-checking instruction.

10. The switching control device according to any one of claims 1 to 9, wherein, The electronic switch (120) comprises a semiconductor switch; The sensor (210) comprises a current transformer.

11. A switching control method (600) of a hybrid switch circuit, the hybrid switch circuit comprising an electronic switch (120), an isolating contact (112) in series with the electronic switch (120), an arcing prevention contact (114) in parallel with the electronic switch (120), a sensor (210) connected with the electronic switch (120), wherein, The method comprises: Identifying a device switching instruction (602); In a case where the device switching instruction is identified as a device closing instruction, performing a device closing operation (604), comprising: closing the isolation contact (112) and the electronic switch (120), sensing a current change of the electronic switch (120) by the sensor (210), and in a case where it is determined that current flows through the electronic switch (120), closing the arc prevention contact (114) and opening the electronic switch (120); or In a case where the device switching instruction is identified as a device opening instruction, performing a device opening operation (606), comprising: closing the electronic switch (120) and opening the arc prevention contact (114), and sensing a current change of the electronic switch (120) by the sensor (210), and in a case where it is determined that current flows through the electronic switch (120), opening the electronic switch (120) and the isolation contact (112).

12. The handover control method according to claim 11, wherein The device closing operation (604) comprises: In response to the device closing instruction, closing the isolation contact (112) and the electronic switch (120), wherein a first time point at which the electronic switch (120) starts to perform the closing operation is not earlier than a second time point at which the isolation contact (112) starts to perform the closing operation; Based on a sensing signal of the sensor (210), obtaining a first sensing result that current flows through the electronic switch (120) in a case where it is determined that the current flowing through the electronic switch (120) changes from large to small; In response to the first sensing result, closing the arc prevention contact (114); based on the sensing signal of the sensor (210), a second sensing result that the arc-proof contact (114) is completely closed is obtained in a case that a falling edge of the sensing signal is detected; the electronic switch (120) is turned off in response to the second sensing result.

13. The handover control method according to claim 11, wherein The device opening operation (606) comprises: the electronic switch (120) is turned on and the arc-proof contact (114) is turned off in response to the device opening instruction, wherein a third time point at which the arc-proof contact (114) starts to perform the opening operation is not earlier than a fourth time point at which the electronic switch (120) starts to perform the closing operation; based on the sensing signal of the sensor (210), a third sensing result that current flows through the electronic switch (120) is obtained in a case that the current flowing through the electronic switch (120) is determined to change from small to large; a turn-off starting time is determined based on a generation time point of the third sensing result and a preset delay time; the electronic switch (120) and the isolation contact (112) are turned off in response to a determination result that a current time meets the turn-off starting time, wherein a fifth time point at which the isolation contact (112) starts to perform the opening operation is not earlier than a sixth time point at which the electronic switch (120) starts to perform the opening operation.

14. The handover control method according to claim 11, wherein The method (700) further comprises: after the device switching instruction is received, a self-checking procedure of the sensor (210) is performed (702); if a self-checking result of the self-checking procedure is that a running state of the sensor (210) is normal, the device switching instruction is continuously executed, and if the self-checking result is that the running state of the sensor (210) is abnormal, the device switching instruction is stopped (704, 706).

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