Hybrid protective switch and circuit breaker
By designing a hybrid protection switch, including first, second, and third switch modules, the mechanical failure and insufficient fast protection of existing DC circuit breakers when interrupting large currents are solved, achieving fast disconnection and secondary protection, ensuring power system safety, and is suitable for electrical equipment such as circuit breakers.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI LIANGXIN ELECTRICAL CO LTD
- Filing Date
- 2025-05-07
- Publication Date
- 2026-06-16
AI Technical Summary
Existing hybrid DC circuit breakers have a high probability of mechanical break commutation failure when interrupting large currents, which cannot meet the requirements of microsecond-level fast protection. They also lack effective secondary protection mechanisms, resulting in excessively long fault clearing times, increasing the risk of cascading faults in the system, and affecting the safe operation of the DC power grid.
Design a hybrid protection switch, including a first switch module, a second switch module and a third switch module. The first switch module disconnects under abnormal current, the second switch module disconnects after absorbing energy, and the third switch module cuts off the main circuit in time when the first switch module fails, forming a secondary protection mechanism.
It achieves rapid disconnection of abnormal current and absorption of energy within less than 2ms, timely disconnection of the main circuit through monitoring by the third switch module, reduces the risk of faults, ensures the safe and stable operation of the power system, and has a response speed of less than 200μs.
Smart Images
Figure CN224367532U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of electrical equipment technology, and more specifically, to a hybrid protection switch and circuit breaker. Background Technology
[0002] With the rapid development of DC power transmission technology, DC circuit breakers, as key protection devices for DC power grids, directly affect the safe and stable operation of the system.
[0003] However, existing hybrid DC circuit breakers still face numerous technical bottlenecks in practical applications. For example, when breaking large currents, excessively high breaking currents significantly increase the probability of mechanical contact commutation failure, severely impacting the reliability and stability of the circuit breaker. Furthermore, existing protection devices struggle to meet the microsecond-level rapid protection requirements of modern DC systems, resulting in excessively long fault clearing times and a lack of effective rapid secondary protection mechanisms. This prevents timely intervention when faults escalate, increasing the risk of cascading failures and seriously threatening the safe operation of the DC power grid. These problems severely restrict the application of hybrid DC circuit breakers in high-voltage, high-capacity DC systems, necessitating the development of a novel hybrid DC circuit breaker and its control method to address these technical challenges. Utility Model Content
[0004] This utility model provides a hybrid protection switch and circuit breaker, which can quickly disconnect and absorb energy in the event of abnormal current in the main circuit through the first and second switch modules, and promptly disconnect the main circuit again in the event of failure of the first switch module through the third switch module, thereby forming a secondary protection mechanism and effectively reducing the fault risk of the power system.
[0005] The embodiments of this utility model can be implemented as follows:
[0006] In a first aspect, this utility model provides a hybrid protection switch, comprising:
[0007] Main circuit;
[0008] A first switch module is disposed in the main circuit and is used to disconnect in case of abnormal current in the main circuit.
[0009] The second switch module is connected in parallel with the first switch module. The second switch module is used to absorb energy and disconnect when the main circuit current is abnormal.
[0010] A third switch module is disposed in the main circuit and connected in series with the first switch module. The third switch module is used to disconnect the main circuit in the event that the first switch module fails to disconnect.
[0011] In an optional implementation, the hybrid protection switch further includes a first signal branch, through which the third switch module detects the arc voltage of the first switch module and is used to cut off the main circuit when the detected arc voltage is greater than a preset threshold.
[0012] In an optional implementation, the third switching module includes a detection unit connected in parallel with the first switching module through the first signal branch, which is used to detect the arc voltage of the first switching module.
[0013] In an optional embodiment, the third switch module further includes a fast response device and a cutting element. The fast response device is connected to the detection unit through the first signal branch. The fast response device is used to receive the arc voltage detected by the detection unit and to control the cutting element to cut off the main circuit when the arc voltage is greater than a preset threshold.
[0014] In an optional implementation, the detection unit is connected to the third switch module via the first signal branch.
[0015] In an optional embodiment, the first switch module further includes a control signal circuit and a circuit breaker. The control signal circuit is connected to the circuit breaker and is used for the power connection. The circuit breaker is disposed in the main circuit and is used to disconnect or connect the main circuit under the control of the control signal circuit.
[0016] In an optional embodiment, the circuit breaker includes an electromagnetic component, a moving contact, and two stationary contacts. The electromagnetic component is disposed in the control signal circuit, the moving contact is disposed in the electromagnetic component, and the two stationary contacts are respectively connected to two sections of the main circuit. The control signal circuit is used to energize the electromagnetic component so that the electromagnetic component drives the moving contact to move toward or away from the stationary contact, thereby driving the moving contact to close or open with the stationary contact.
[0017] In an optional embodiment, the second switching module includes an energy absorption branch and an isolating switch connected in series. The energy absorption branch is used to absorb energy in the event of an abnormality in the main circuit current, and the isolating switch is used to disconnect the circuit after the energy absorption branch has absorbed energy.
[0018] In an optional embodiment, the second switching module further includes a power electronic branch connected in parallel with the energy absorption branch.
[0019] Secondly, this utility model provides a circuit breaker, including a hybrid protection switch as described in any of the foregoing embodiments.
[0020] The beneficial effects of the hybrid protection switch and circuit breaker provided in this embodiment of the invention include: in the event of a short circuit or other circuit abnormality in the main circuit, the first switch module installed in the main circuit can detect the fault current and disconnect, allowing the current to be diverted to the second switch module connected in parallel with the first switch module. The second switch module then absorbs energy and disconnects, thereby completely cutting off the current in the main circuit while reducing the impact of voltage on electrical components, effectively ensuring the safe operation of the power system. Furthermore, by setting a third switch module in parallel with the first switch module to monitor the disconnection status of the first switch module, the main circuit can be promptly cut off in the event of a failure in the first switch module's disconnection, such as when the first switch module generates arc voltage during disconnection, further ensuring the complete disconnection of the main circuit. Therefore, the hybrid protection switch provided in this embodiment of the invention can quickly disconnect and absorb energy in the event of an abnormal current in the main circuit through the first and second switch modules, and promptly disconnect the main circuit again through the third switch module in the event of a failure in the first switch module, thus forming a secondary protection mechanism and effectively reducing the fault risk of the power system. Attached Figure Description
[0021] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0022] Figure 1 One of the schematic diagrams of a hybrid protection switch provided in the embodiments of this utility model;
[0023] Figure 2 This is the second schematic diagram of a hybrid protection switch provided in an embodiment of the present utility model;
[0024] Figure 3 The third schematic diagram of the hybrid protection switch provided in this embodiment of the utility model;
[0025] Figure 4 The fourth schematic diagram of the hybrid protection switch provided in the embodiment of this utility model.
[0026] Icons: 10-Hybrid protection switch; 100-Main circuit; 200-First switch module; 210-Control signal circuit; 220-Circuit breaker; 221-Electromagnetic component; 222-Moving contact; 223-Stationary contact; 300-Second switch module; 310-Energy absorption branch; 320-Isolating switch; 330-Power electronics branch; 400-Third switch module; 410-Detection unit; 420-Fast response device; 430-Cutting component; 500-First signal branch. Detailed Implementation
[0027] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0028] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0029] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0030] In the description of this utility model, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the utility model product is usually placed during use, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
[0031] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.
[0032] It should be noted that, where there is no conflict, the features in the embodiments of this utility model can be combined with each other.
[0033] With the rapid development of DC transmission technology, DC circuit breakers, as key protection devices for DC power grids, directly affect the safe and stable operation of the system. However, existing hybrid DC circuit breakers still face several technical bottlenecks in practical applications: First, when breaking large currents, especially when the breaking current exceeds 20kA and the reverse recovery voltage is higher than 10kV, the probability of mechanical break commutation failure increases significantly, severely impacting the reliability and stability of the circuit breaker. Second, when traditional fuses are used as backup protection devices, their operating time generally exceeds 10ms, which is insufficient to meet the microsecond-level fast protection requirements of modern DC systems, resulting in excessively long fault clearing times. Furthermore, existing technologies lack effective fast secondary protection mechanisms, failing to take timely protective measures when faults escalate, increasing the risk of cascading faults and seriously threatening the safe operation of the DC power grid. These problems severely restrict the application of hybrid DC circuit breakers in high-voltage, high-capacity DC systems, necessitating the development of a new type of hybrid DC circuit breaker and its control method to solve these technical challenges.
[0034] Based on the problems existing in the prior art, this utility model provides a hybrid protection switch, which is applied in the field of power system protection technology, and is especially suitable for circuit breakers and other related electrical equipment.
[0035] For details, please refer to Figure 1 The hybrid protection switch 10 includes a main circuit 100 (as shown in S1-S2 in the figure), a first switch module 200, a second switch module 300, and a third switch module 400.
[0036] In this embodiment, the first switch module 200 is a mechanical switch module, the second switch module 300 is a solid-state switch module, and the third switch module 400 is a protection switch module.
[0037] The first switch module 200 is disposed in the main circuit 100 and is used to disconnect the main circuit 100 in case of abnormal current. The second switch module 300 is connected in parallel with the first switch module 200 and is used to disconnect the main circuit 100 after absorbing energy in case of abnormal current. The third switch module 400 is disposed in the main circuit 100 and connected in series with the first switch module 200. The third switch module 400 is used to disconnect the main circuit 100 in case the first switch module 200 fails to disconnect.
[0038] In this embodiment, the first switch module 200 is normally closed, and at this time the current flows through the main circuit 100.
[0039] In the event of a short circuit or other circuit abnormality in the main circuit 100, the first switch module 200 installed in the main circuit 100 can detect the fault current and disconnect it, so that the current is diverted to the second switch module 300 connected in parallel with the first switch module 200. The second switch module 300 then disconnects after absorbing energy, thereby completely cutting off the current in the main circuit 100 while reducing the impact of voltage on electrical components, thus effectively ensuring the safe operation of the power system.
[0040] It is worth mentioning that the entire process has a response time of less than 2ms, which is fast.
[0041] In addition, a third switch module 400 is connected in series with the first switch module 200 to monitor the disconnection status of the first switch module 200. In the event that the first switch module 200 fails to disconnect, such as when the first switch module 200 generates arc voltage during disconnection, the main circuit 100 is cut off in time, further ensuring that the main circuit 100 is completely disconnected.
[0042] It is worth mentioning that the response speed of the third switch module 400 is less than 200μs.
[0043] Therefore, the hybrid protection switch 10 provided in this embodiment of the present invention can quickly disconnect and absorb energy when an abnormal current occurs in the main circuit 100 through the first switch module 200 and the second switch module 300, and can promptly disconnect the main circuit 100 again through the third switch module 400 when the first switch module 200 fails, thereby forming a secondary protection mechanism and effectively reducing the fault risk of the power system.
[0044] Among them, the first switch module 200 and the second switch module 300 serve as the main protection modules of the main circuit 100, and the timing coordination error between them and the third switch module 400 serves as the backup protection module is <10μs.
[0045] For further information, please refer to [link / reference]. Figure 2 and Figure 3 The hybrid protection switch 10 also includes a first signal branch 500, through which the third switch module 400 detects the arc voltage of the first switch module 200 and is used to cut off the main circuit 100 when the detected arc voltage is greater than a preset threshold.
[0046] In this embodiment, the first signal branch 500 includes two excitation signal lines, which are connected to the main circuit 100 and located at both ends of the first switch module 200. Therefore, the third switch module 400 detects the arc voltage of the first switch module 200 in the main circuit 100 through the excitation signal lines of the first signal branch 500, thereby determining whether the first switch module 200 is effectively disconnected.
[0047] It is understandable that after the first switch module 200 completes the disconnection action, if the third switch module 400 can still detect the arc voltage at both ends of the main circuit 100 of the first switch module 200 and the arc voltage is greater than the preset arc voltage threshold, then the disconnection of the first switch module 200 is determined to be unsuccessful; conversely, if the third switch module 400 fails to detect the arc voltage at both ends of the main circuit 100 of the first switch module 200, then the first switch module 200 is determined to be effectively disconnected.
[0048] In detail, the third switch module 400 includes a detection unit 410, a rapid response device 420, and a cutting element 430.
[0049] The detection unit 410 is connected in parallel with the first switch module 200 through the first signal branch 500 and is used to detect the arc voltage of the first switch module 200.
[0050] The rapid response device 420 is connected in parallel with the detection unit 410 through the first signal branch 500. The rapid response device 420 is used to receive the arc voltage detected by the detection unit 410 and to control the cutting component 430 to cut off the main circuit 100 when the arc voltage is greater than a preset threshold.
[0051] In this embodiment, when the fast response device 420 receives a signal that the first switch module 200 has failed to disconnect, the fast response device 420 can react quickly, that is, quickly cut off the circuit with abnormally high current through the cutting element 430, which helps to reduce damage caused by short circuit or other electrical faults and protect downstream equipment from being affected.
[0052] Therefore, by setting up the detection unit 410, the rapid response device 420, and the cutting element 430, the reliability of the entire power system is improved, an additional safety barrier is provided for the electrical system, and it is ensured that a rapid and effective response can be made in the face of emergencies.
[0053] Specifically, the third switch module 400 can be an activated fuse, including a fast-response device 420 and a cutter 430. The fast-response device 420 can be a gas generator, abbreviated as MGG in the industry, and the cutter 430 can be a piston. When activated, the fast-response device 420 explodes to generate high-pressure gas, which drives the cutter 430 to cut off the main circuit 100.
[0054] Understandable, such as Figure 4 As shown, the detection unit 410 can be part of 400 or independent of 400.
[0055] Specifically, the detection unit 410 is connected in parallel with the first switch module 200 through the first signal branch 500, and is also connected to the third switch module 400 through the first signal branch 500.
[0056] In detail, the first switch module 200 also includes a control signal circuit 210 and a circuit breaker 220. The control signal circuit 210 is connected to the circuit breaker 220 and is used to connect to the power supply. The circuit breaker 220 is located in the main circuit 100 and is used to disconnect or connect the main circuit 100 under the control of the control signal circuit 210.
[0057] The circuit breaker 220 includes an electromagnetic element 221, a moving contact 222, and two stationary contacts 223. The electromagnetic element 221 is located in the control signal circuit 210, the moving contact 222 is located in the electromagnetic element 221, and the two stationary contacts 223 are respectively connected to two main circuits 100. The control signal circuit 210 is used to energize the electromagnetic element 221 so that the moving contact 222 moves toward or away from the stationary contact 223, thereby causing the moving contact 222 to close or open with the stationary contact 223.
[0058] Furthermore, the second switch module 300 includes an energy absorption branch 310 and an isolating switch 320 connected in series. The energy absorption branch 310 is used to absorb energy in the event of an abnormal current in the main circuit 100, and the isolating switch 320 is used to disconnect the circuit after the energy absorption branch 310 absorbs energy.
[0059] In this embodiment, the energy absorption branch 310 is mainly used to absorb excess electrical energy when the circuit breaker operates, so as to prevent this energy from damaging other electrical components, equipment or systems.
[0060] Specifically, when the first switching module 200 cuts off the current, especially the current of highly inductive loads (such as motors and transformers), transient overvoltages may occur. If excessive energy cannot be dissipated in time, it may cause system oscillations or other instabilities. Therefore, the energy absorption branch 310 can effectively absorb this energy, thereby reducing the impact of overvoltages on insulation materials and other electrical components.
[0061] Furthermore, by absorbing and dissipating the energy generated during the disconnection process, the energy absorption branch 310 helps reduce the intensity and duration of the electric arc between the contacts, thereby mitigating contact erosion and wear and extending their service life.
[0062] Therefore, the energy absorption branch 310 can help maintain the stable operation of the entire power system, ensuring that the circuit breaker can maintain good working condition under various operating conditions, such as quickly and reliably interrupting fault current, while minimizing unnecessary interference.
[0063] Furthermore, the second switch module 300 also includes a power electronics branch 330, which is connected in parallel with the energy absorption branch 310.
[0064] In this embodiment, by setting up a power electronic branch 330, the fast switching characteristics of power electronic devices (such as IGBTs, MOSFETs, etc.) can be utilized to achieve rapid control and cut-off of current.
[0065] Therefore, by setting up the power electronic branch 330, the functionality and reliability of the circuit breaker are greatly enhanced, enabling it to better adapt to the needs of complex and ever-changing power environments.
[0066] In summary, this utility model embodiment provides a hybrid protection switch 10. When a short circuit or other circuit abnormality occurs in the main circuit 100, the first switch module 200, located in the main circuit 100, detects the fault current and disconnects, allowing the current to be diverted to a second switch module 300 connected in parallel with the first switch module 200. The second switch module 300 then disconnects after absorbing energy, thereby completely cutting off the current in the main circuit 100 while reducing the impact of voltage on electrical components, effectively ensuring the safe operation of the power system. Furthermore, a third switch module 400 is connected in series with the first switch module 200 to monitor the disconnection status of the first switch module 200. This allows for timely disconnection of the main circuit 100 in case the first switch module 200 fails to disconnect, such as when arcing occurs during disconnection, further ensuring the complete disconnection of the main circuit 100. Therefore, the hybrid protection switch 10 provided in this embodiment of the present invention can quickly disconnect and absorb energy when an abnormal current occurs in the main circuit 100 through the first switch module 200 and the second switch module 300, and can promptly disconnect the main circuit 100 again through the third switch module 400 when the first switch module 200 fails, thereby forming a secondary protection mechanism and effectively reducing the fault risk of the power system.
[0067] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.
Claims
1. A hybrid protective switch, characterized in that, include: Main circuit (100); A first switch module (200) is disposed in the main circuit (100) and is used to disconnect in the event of an abnormal current in the main circuit (100). The second switch module (300) is connected in parallel with the first switch module (200). The second switch module (300) is used to absorb energy and disconnect in the event of an abnormal current in the main circuit (100). A third switch module (400) is disposed in the main circuit (100) and connected in series with the first switch module (200). The third switch module (400) is used to disconnect the main circuit (100) in the event that the first switch module (200) fails to disconnect.
2. The hybrid protection switch according to claim 1, characterized in that, The hybrid protection switch also includes a first signal branch (500), and the third switch module (400) detects the arc voltage of the first switch module (200) through the first signal branch (500) and is used to cut off the main circuit (100) when the detected arc voltage is greater than a preset threshold.
3. The hybrid protection switch according to claim 2, characterized in that, The third switch module (400) includes a detection unit (410), which is connected in parallel with the first switch module (200) through the first signal branch (500) and is used to detect the arc voltage of the first switch module (200).
4. The hybrid protection switch according to claim 3, characterized in that, The third switch module (400) further includes a fast response device (420) and a cutting element (430). The fast response device (420) is connected to the detection unit (410) through the first signal branch (500). The fast response device (420) is used to receive the arc voltage detected by the detection unit (410) and to control the cutting element (430) to cut off the main circuit (100) when the arc voltage is greater than a preset threshold.
5. The hybrid protection switch according to claim 3, characterized in that, The detection unit (410) is connected to the third switch module (400) through the first signal branch (500).
6. The hybrid protection switch according to claim 1, characterized in that, The first switch module (200) further includes a control signal circuit (210) and a circuit breaker (220). The control signal circuit (210) is connected to the circuit breaker (220) and is used to connect to the power supply. The circuit breaker (220) is located in the main circuit (100) and is used to disconnect or connect the main circuit (100) under the control of the control signal circuit (210).
7. The hybrid protection switch according to claim 6, characterized in that, The circuit breaker (220) includes an electromagnetic element (221), a moving contact (222), and two stationary contacts (223). The electromagnetic element (221) is located in the control signal circuit (210), and the moving contact (222) is located in the electromagnetic element (221). The two stationary contacts (223) are respectively connected to two sections of the main circuit (100). The control signal circuit (210) is used to energize the electromagnetic element (221) so that the moving contact (222) moves toward or away from the stationary contact (223) through the electromagnetic element (221), thereby causing the moving contact (222) to close or open with the stationary contact (223).
8. The hybrid protection switch according to claim 1, characterized in that, The second switch module (300) includes an energy absorption branch (310) and an isolating switch (320) connected in series. The energy absorption branch (310) is used to absorb energy in the event of an abnormal current in the main circuit (100), and the isolating switch (320) is used to disconnect the circuit after the energy absorption branch (310) absorbs energy.
9. The hybrid protection switch according to claim 8, characterized in that, The second switching module (300) further includes a power electronic branch (330), which is connected in parallel with the energy absorption branch (310).
10. A circuit breaker, characterized in that, Including the hybrid protection switch as described in any one of claims 1-9.