Switching device and control method therefor, related devices

Abstract

The application discloses a switching device and a control method thereof and a related device. The switching device comprises a mechanical switch, a coil and a switching circuit. The mechanical switch comprises mechanical contacts. The coil controls the mechanical contacts to close or open based on electromagnetic control. The switching circuit is connected with the coil. In response to receiving a breaking signal, the switching circuit switches the equivalent inductance of the coil. The equivalent inductance of the switched coil is smaller than that of the coil before switching. The switching device can effectively reduce the time constant of current decay in the coil by reducing the equivalent inductance of the coil, thereby effectively improving the breaking response speed of the switching device.

Description

Technical Field

[0001] This application relates to the field of electrical switch technology, and more specifically, to a switch device and its control method and related devices. Background Technology

[0002] As the core control device used to connect and disconnect circuits, the performance of the switching device directly affects the timeliness and safety of power supply system control. For example, in situations requiring rapid response to faults or changes in operating modes, such as during the switching of power supply systems between grid and off-grid systems, the breaking speed of the switching device is crucial.

[0003] In related technologies, electromagnetically operated mechanical switches are commonly used to construct switching devices. The opening action of their mechanical contacts relies on the magnetic field generated by the coil used to drive the mechanical contacts. When disconnection is required, the power supply to the coil is usually cut off. The current in the coil naturally decays due to the freewheeling circuit formed by the coil itself and the freewheeling branch, and the magnetic field weakens until the mechanical contacts open. This process results in a disconnection response time of electromagnetically operated switching devices in related technologies that is typically greater than tens of milliseconds.

[0004] This response speed has significant limitations when facing high-frequency, fast-action scenarios, making it difficult to meet the stringent requirements of instantaneous response in systems. Especially for loads highly sensitive to power quality, such as semiconductor manufacturing lines and precision medical imaging equipment, a power outage exceeding 10ms can easily trigger equipment shutdown protection or lead to the loss of critical process data. Clearly, the breaking response speed of existing switching devices urgently needs to be improved. Summary of the Invention

[0005] This application provides a switching device and its control method, as well as related devices. The various aspects involved in this application's embodiments are described below.

[0006] In a first aspect, a switching device is provided, including a mechanical contact, a coil, and a switching circuit, wherein the coil controls the mechanical contact to close or open based on electromagnetic control, and the switching circuit is connected to the coil. In response to receiving a disconnection signal, the switching circuit switches the equivalent inductance of the coil, wherein the equivalent inductance of the coil after switching is less than the equivalent inductance of the coil before switching.

[0007] In some embodiments, the coil has a first connection topology and a second connection topology, the equivalent inductance of the coil in the second connection topology is less than the equivalent inductance of the coil in the first connection topology, and in response to receiving the disconnection signal, the switching circuit switches the coil from the first connection topology to the second connection topology.

[0008] In some embodiments, in response to receiving an engagement signal, the switching circuit switches the coil from the second connection topology state to the first connection topology state.

[0009] In some embodiments, the coil includes multiple winding segments, the first connection topology is that the multiple winding segments are connected in series, and the second connection topology is that the multiple winding segments are all connected in parallel.

[0010] In some embodiments, the switching circuit includes a plurality of switching switches connected to the multi-segment winding. The plurality of switching switches have a first on / off state and a second on / off state. When the plurality of switching switches are in the first on / off state, the coil is in the first connection topology state. When the plurality of switching switches are in the second on / off state, the coil is in the second connection topology state.

[0011] In some embodiments, the multiple winding segments are wound on the same iron core.

[0012] In some embodiments, the switching device further includes a semiconductor switch connected in parallel with the mechanical contacts, wherein the semiconductor switch is turned on in response to receiving the disconnection signal or the engagement signal.

[0013] In some embodiments, the switching device further includes a voltage conversion circuit connected between the driving circuit and the power supply terminal of the coil. The voltage conversion circuit is used to provide a converted driving voltage to the power supply terminal of the coil. The converted driving voltage includes a forward driving voltage, a reverse driving voltage, or a zero-value driving voltage.

[0014] In some embodiments, the switching device further includes a control unit, the voltage conversion circuit being connected to the control unit, the control unit being configured to perform the following control methods: in response to receiving the disconnection signal, controlling the voltage conversion circuit to provide the 0-value driving voltage or the reverse driving voltage to the power supply terminal of the coil; or, in response to receiving the pull-in signal, controlling the voltage conversion circuit to provide the forward driving voltage to the power supply terminal of the coil.

[0015] In some embodiments, the voltage conversion circuit includes a first bridge arm and a second bridge arm connected in parallel. The first bridge arm includes a first power device and a second power device connected in series. The second bridge arm includes a third power device and a fourth power device connected in series. Both ends of the first bridge arm and the second bridge arm are connected to a driving voltage. The midpoint of the first bridge arm is connected to the positive power supply terminal of the coil, and the midpoint of the second bridge arm is connected to the negative power supply terminal of the coil. The control unit is configured to perform one of the following control methods: controlling the first power device and the fourth power device to be turned on and the second power device and the third power device to be turned off, so that the voltage conversion circuit provides the positive driving voltage to the power supply terminal of the coil; controlling the first power device... The voltage conversion circuit provides the zero-value driving voltage to the power supply terminal of the coil by controlling the second and third power devices to be turned on and the first and third power devices to be turned off; and the voltage conversion circuit provides the reverse driving voltage to the power supply terminal of the coil by controlling the second and third power devices to be turned on and the first and fourth power devices to be turned off. Wherein, the first and fourth power devices are both controllable switches, and the second and third power devices are both controllable switches or diodes.

[0016] In some embodiments, the switching device further includes: a freewheeling diode, the anode of which is connected to the negative power supply terminal of the coil, and the cathode of which is connected to the positive power supply terminal of the coil to form a freewheeling circuit; and a negative voltage circuit disposed between the anode of the freewheeling diode and the negative power supply terminal of the coil, the negative voltage circuit being configured to provide a reverse voltage to the power supply terminal of the coil in response to the disconnection of the power supply terminal of the coil from the driving circuit.

[0017] In some embodiments, the negative voltage circuit includes a voltage source, which includes a positive output terminal and a negative output terminal. The positive output terminal is connected to the negative power supply terminal of the coil, and the negative output terminal is connected to the anode of the freewheeling diode.

[0018] In some embodiments, the reverse voltage provided by the voltage source is adjustable.

[0019] In some embodiments, the negative voltage circuit includes a voltage clamping device.

[0020] In a second aspect, a control method for a switching device is provided. The switching device includes a mechanical switch, which includes mechanical contacts, a coil, and a switching circuit. The coil controls the mechanical contacts to close or open based on electromagnetic control. The switching circuit is connected to the coil. The control method includes: in response to receiving a disconnection signal, controlling the switching circuit to switch the equivalent inductance of the coil, wherein the equivalent inductance of the switched coil is less than the equivalent inductance of the coil before switching.

[0021] In some embodiments, the coil has a first connection topology and a second connection topology, and the equivalent inductance of the coil in the second connection topology is less than its equivalent inductance in the first connection topology; the step of controlling the switching circuit to switch the equivalent inductance of the coil in response to receiving a disconnection signal includes: in response to receiving the disconnection signal, controlling the switching circuit to switch the coil from the first connection topology to the second connection topology.

[0022] In some embodiments, the control method further includes: in response to receiving an engagement signal, controlling the switching circuit to switch the coil from the second connection topology state to the first connection topology state.

[0023] In some embodiments, the switching device further includes a semiconductor switch connected in parallel with the mechanical contacts, and the control method further includes: controlling the semiconductor switch to turn on in response to receiving the disconnection signal or the activation signal.

[0024] In some embodiments, the switching device further includes a voltage conversion circuit connected between the driving circuit and the power supply terminal of the coil. The voltage conversion circuit is used to provide a converted driving voltage to the power supply terminal of the coil. The converted driving voltage includes a forward driving voltage, a reverse driving voltage, or a zero-value driving voltage. The control method further includes: in response to receiving the disconnection signal, controlling the voltage conversion circuit to provide the zero-value driving voltage or the reverse driving voltage to the power supply terminal of the coil; or, in response to receiving the pull-in signal, controlling the voltage conversion circuit to provide the forward driving voltage to the power supply terminal of the coil.

[0025] In some embodiments, the voltage conversion circuit includes a first bridge arm and a second bridge arm connected in parallel. The first bridge arm includes a first power device and a second power device connected in series, and the second bridge arm includes a third power device and a fourth power device connected in series. Both ends of the first and second bridge arms are connected to a driving voltage. The midpoint of the first bridge arm is connected to the positive power supply terminal of the coil, and the midpoint of the second bridge arm is connected to the negative power supply terminal of the coil. The first and fourth power devices are both controllable switches, and the second and third power devices are both controllable switches or diodes. The voltage conversion circuit is controlled to provide the positive driving voltage to the power supply terminal of the coil. The control includes: turning on the first power device and the fourth power device while turning off the second power device and the third power device; controlling the voltage conversion circuit to provide the 0-value driving voltage to the power supply terminal of the coil includes: turning on the first power device and the third power device while turning off the second power device and the fourth power device, or, turning on the second power device and the fourth power device while turning off the first power device and the third power device; controlling the voltage conversion circuit to provide the reverse driving voltage to the power supply terminal of the coil includes: turning on the second power device and the third power device while turning off the first power device and the fourth power device.

[0026] In some embodiments, the switching device further includes a freewheeling diode and a negative voltage circuit, wherein the anode of the freewheeling diode is connected to the negative power supply terminal of the coil, the cathode of the freewheeling diode is connected to the positive power supply terminal of the coil, and the negative voltage circuit is disposed between the anode of the freewheeling diode and the negative power supply terminal of the coil; the control method further includes: in response to the disconnection of the power supply terminal of the coil from the driving circuit, providing a reverse voltage to the power supply terminal of the coil through the negative voltage circuit.

[0027] Thirdly, a controller is provided for performing the control method as described in the second aspect.

[0028] Fourthly, a power supply system is provided, comprising: a switching device as described in the first aspect; and a power converter connected to an external circuit via the switching device.

[0029] The switching device proposed in this application incorporates a switching circuit in its mechanical switch. This switching circuit can switch the equivalent inductance of the coil when disconnection is required, ensuring that the equivalent inductance of the coil after switching is less than that before switching. Based on this, the time constant for current decay in the coil of the mechanical switch can be effectively reduced by decreasing the equivalent inductance of the coil, thereby reducing the disconnection response delay caused by the fixed inductance of the mechanical switch and effectively improving the disconnection response speed of the switching device. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a switching device in related technologies.

[0031] Figure 2 This is a schematic diagram of the structure of a switching device provided in an embodiment of this application.

[0032] Figure 3 This is a schematic diagram of the freewheeling circuit of the mechanical switch in a switching device provided in an embodiment of this application.

[0033] Figure 4 This is a schematic diagram of the structure of a switching device provided in another embodiment of this application.

[0034] Figure 5 This is a schematic diagram of the freewheeling circuit of the mechanical switch in a switching device provided in another embodiment of this application.

[0035] Figure 6 This is a schematic diagram of the freewheeling circuit of the mechanical switch in a switching device provided in another embodiment of this application.

[0036] Figure 7 This is a schematic diagram of the freewheeling circuit of the mechanical switch in a switching device provided in another embodiment of this application.

[0037] Figure 8 yes Figure 7 A possible structural diagram of a negative voltage circuit in [the circuit].

[0038] Figure 9 This is a schematic diagram of the freewheeling circuit of the mechanical switch in a switching device provided in another embodiment of this application.

[0039] Figure 10 This is a schematic diagram of a power supply system provided in an embodiment of this application.

[0040] Figure 11 This is a schematic flowchart of a control method for a switching device provided in an embodiment of this application. Detailed Implementation

[0041] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application should fall within the scope of protection of the present application.

[0042] References to embodiments herein mean that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0043] In power systems, switching devices are typically installed to ensure reliable circuit connection and disconnection. As the core control device for circuit connection and disconnection, the performance of the switching device directly affects the timeliness and safety of the power supply system control. For example, when switching devices are applied to energy storage power supply systems, in the event of a grid fault (such as a short circuit, power outage, or voltage drop), the energy storage power supply system needs to quickly switch from grid-connected mode to off-grid mode. As a grid-connected / off-grid switching device, the switching speed of the switching device is crucial, ensuring the uninterrupted operation of sensitive critical loads such as precision manufacturing and data centers.

[0044] In related technologies, electromagnetically operated mechanical switches are commonly used to construct switching devices, such as contactors or circuit breakers. These switching devices include mechanical contacts and coils, with the coils controlling the mechanical contacts to close (or engage or conduct) or open (or disengage or disconnect) based on electromagnetic control. Specifically: For example... Figure 1 As shown, the switching device 100 includes a mechanical switch 110, which includes mechanical contacts 111 and a coil 112. The coil 112, together with the current-limiting resistor R and the diode D1, forms a freewheeling circuit. Whether the coil 112 is energized is controlled by a coil control circuit switch K1. When the mechanical contacts need to close, K1 closes to energize the coil 112, generating electromagnetic force that drives the mechanical contacts 111 to close. When the mechanical contacts need to open, K1 opens to cut off the current to the coil 112. The current in the coil 112 naturally decays due to the freewheeling circuit, weakening the magnetic field until the mechanical contacts 111 open. Figure 1 Middle U C The driving voltage provided by the driving circuit to the coil.

[0045] However, to avoid accidental activation, the electromagnetic force required for the mechanical contact 111 to engage is relatively large. Therefore, the coil 112 in the switching device is typically a large inductance coil. After receiving the disconnection signal, the current in coil 112 decays naturally according to a fixed time constant (τ=L / R, where L is the equivalent inductance of coil 112 and R is the resistance of the current-limiting resistor in the freewheeling branch). The mechanical contact 111 must wait for the current in coil 112 to drop below a specific threshold before disconnecting. According to the above time constant formula, the large inductance of coil 112 results in a slow release of magnetic field energy in the freewheeling circuit, leading to a disconnection response time in electromagnetically operated switching devices typically greater than tens of milliseconds. Furthermore, considering the impact of the arc-extinguishing process, the disconnection response time can even reach between 20 and 100 milliseconds.

[0046] This response speed has significant limitations when facing high-frequency, fast-action scenarios, making it difficult to meet the stringent requirements of instantaneous response in systems. Especially for loads highly sensitive to power quality, such as semiconductor manufacturing lines and precision medical imaging equipment, a power outage exceeding 10ms can easily trigger equipment shutdown protection or lead to the loss of critical process data. Clearly, the breaking response speed of existing switching devices urgently needs to be improved to meet seamless switching requirements.

[0047] To address the above issues, the mechanical switch in the switching device proposed in this application incorporates a switching circuit. This switching circuit can switch the equivalent inductance of the coil when disconnection is required, ensuring that the equivalent inductance of the coil after switching is less than that before switching. Based on this, without changing the conduction characteristics of the switching device containing the mechanical switch, the time constant for current decay in the coil of the mechanical switch can be effectively reduced by decreasing the equivalent inductance of the coil. This reduces the disconnection response delay time caused by the fixed inductance of the mechanical switch, effectively improving the disconnection response speed of the switching device.

[0048] To facilitate understanding of the embodiments of this application, the following is in conjunction with... Figure 2 The switching device provided in the embodiments of this application will be described by way of example. See details. Figure 2 The switching device 200 includes a mechanical switch 210.

[0049] The mechanical switch 210 can be understood as including physically separable or contactable mechanical contacts 211 and a mechanism that drives the contacts to move by generating electromagnetic force through the excitation of a coil 212. That is, the mechanical switch 210 includes mechanical contacts 211 and a coil 212, with the coil 212 controlling the closing or opening of the mechanical contacts 211 based on electromagnetic effects. Specifically, the coil 212 can be wound on an iron core. When the coil 212 is energized and generates a sufficient magnetic field, it can drive the iron core to move the mechanical contacts 211, causing the mechanical contacts 211 to close. When the coil 212 is de-energized, as the current in the coil 212 decays, the magnetic field gradually weakens until the mechanical contacts 211 open under the action of a return spring, etc. This application does not specifically limit the type of mechanical switch 210. For example, the mechanical switch 210 may include, but is not limited to, switches such as AC contactors, DC contactors, relays, and circuit breakers.

[0050] Coil 212 can be understood as an inductive element made of wire that generates a magnetic field when energized, and it is the excitation part of the electromagnetic operating mechanism. In the embodiments of this application, the equivalent inductance of coil 212 is variable. For example, the equivalent inductance of coil 212 can be related to the connection topology of coil 212. By setting coil 212 to different connection topologies, coil 212 can have different equivalent inductances. Here, the connection topology of coil 212 can be understood as the structural form of the electrical connection of coil 212. In some embodiments, the connection topology of coil 212 can also be referred to as the topological structure of coil 212, or the connection relationship forming the windings of coil 212.

[0051] In the embodiments of this application, such as Figure 2 As shown, the mechanical switch 210 also includes a switching circuit 213 connected to the coil 212, and the switching circuit 213 is used to switch the equivalent inductance of the coil 212. For example, the switching circuit 213 can switch the equivalent inductance of the coil 212 by switching the connection topology of the coil 212. That is, the coil 212 has different equivalent inductances under different connection topologies, and the switching circuit 213 can switch the connection topology of the coil 212 to make the coil 212 exhibit different equivalent inductances. As one implementation, the switching circuit 213 may include at least two controllable switches, and these at least two controllable switches can be connected to different positions of the coil 212. These at least two controllable switches can switch the number of turns of the coil 212 connected to the circuit, thereby switching the equivalent inductance of the coil 212. Different numbers of turns of the coil 212 connected to the circuit can represent different connection topologies of the coil 212.

[0052] In this embodiment, in response to receiving a disconnection signal, the switching circuit 213 switches the equivalent inductance of the coil 212, and the equivalent inductance of the switched coil 212 is less than the equivalent inductance of the coil 212 before switching. The switching circuit 213 switching the equivalent inductance of the coil 212, and the equivalent inductance of the switched coil 212 being less than the equivalent inductance of the coil 212 before switching, can be understood as the switching circuit 213 reducing the equivalent inductance of the coil 212.

[0053] A disconnect signal can be understood as any external or internal command signal that instructs the switching device 200 to perform a disconnect operation. For example, a disconnect signal may include, but is not limited to: logic level signals, pulse signals, or trigger signals automatically generated upon detecting fault conditions such as overcurrent, short circuit, or power failure from the control unit, host computer, or protection circuit. In some embodiments, a disconnect signal may also be referred to as a disconnect command.

[0054] The equivalent inductance of coil 212 can be understood as the total inductance effect exhibited by coil 212. The equivalent inductance is determined by the self-inductance of the windings forming coil 212 and the mutual inductance between the windings, and its value changes with the switching of the connection topology of coil 212. In view of this, the switching circuit 213 can switch the equivalent inductance of coil 212 by switching (or transforming) the topological connection state of coil 212 to switch the equivalent inductance of coil 212.

[0055] In this embodiment, the equivalent inductance of coil 212 before switching can be understood as the equivalent inductance of coil 212 before the start of the disconnection operation (i.e., when it is in steady-state conduction or in-phase hold), and the equivalent inductance after switching can be understood as the equivalent inductance of coil 212 after the start of the disconnection operation. The reduction in the equivalent inductance of coil 212 after switching relative to the equivalent inductance of coil 212 before switching can be designed as needed. For example, the equivalent inductance of coil 212 after switching can be 1 / 2, 1 / 4, 1 / 9, 1 / 16, or lower than the equivalent inductance of coil 212 before switching.

[0056] The aforementioned response to the received disconnection signal provides a clear triggering condition and timing start point for the subsequent action of the switching circuit 213 to reduce the equivalent inductance of coil 212. Reducing the equivalent inductance of coil 212 is a physical intervention directly acting on the electromagnetic inertial root (inductance L). By not only initiating the conventional power-off process at the instant the switching device 200 receives the disconnection signal, but also actively and forcibly switching the electromagnetic parameters of coil 212 by reducing its equivalent inductance through the switching circuit 213, the dissipation of magnetic field energy is fundamentally accelerated, thereby driving the mechanical contact 211 to achieve physical separation much faster than related technical solutions. This synergistic effect solves the problem of delayed separation of mechanical contact 211 caused by the fixed inductance of coil 212, shortening the disconnection response time of the switching device 200 and effectively improving its disconnection response speed.

[0057] As mentioned above, the switching circuit 213 switches the equivalent inductance of coil 212 in a specific way: the switching circuit 213 switches the equivalent inductance of coil 212 by switching the connection topology state of coil 212. To further optimize the reliability and controllability of the connection topology state switching process, in some embodiments, coil 212 has a first connection topology state and a second connection topology state; that is, the connection topology state of coil 212 includes both a first connection topology state and a second connection topology state. The equivalent inductance of coil 212 in the second connection topology state is less than that in the first connection topology state, or in other words, the equivalent inductance of coil 212 in the second connection topology state is less than that in the first connection topology state. The switching circuit 213 is used to switch coil 212 between the first connection topology state and the second connection topology state.

[0058] Based on this configuration, in this embodiment, in response to receiving a disconnection signal, the switching circuit 213 performs a first switch. The first switch involves switching the coil 212 from a first connection topology state to a second connection topology state. In some embodiments, the switching circuit 213 may perform the first switch under the control of a control unit, which may also be configured to cut off the power supply to the coil 212 in response to receiving a disconnection signal. Therefore, the triggering timing of the first switch may be slightly earlier than, synchronized with, or slightly later than the action of cutting off the power supply to the coil 212; the specific timing can be optimized and adjusted according to requirements and circuit design.

[0059] By defining the connection topology of coil 212 as a first connection topology and a second connection topology, and designing the equivalent inductance value of coil 212 in the second connection topology to be smaller than the equivalent inductance value in the first connection topology, the switching of the equivalent inductance of coil 212 can no longer be a continuous or fuzzy adjustment, but rather a jump between two discrete states with different performance. Its advantage is that the specific control logic of the control switching circuit 213 to reduce the equivalent inductance of coil 212 is simple and reliable, the state is clear, it is easy to implement, and the effect is significant.

[0060] As mentioned above, in this embodiment, when the switching device 200 needs to disconnect, the equivalent inductance of the coil 212 is reduced to accelerate the disconnection response speed. To avoid the disconnection process unnecessarily affecting the engagement process, in some embodiments, this embodiment further proposes that, in response to receiving an engagement signal, the switching circuit 213 performs a second switch, which switches the coil 212 from a second connection topology state to a first connection topology state. In other words, the second switch is the reverse operation of the first switch.

[0061] In some embodiments, the switching circuit 213 can perform a second switching under the control of the control unit, which can also be configured to control the drive circuit to supply power to the coil 212 in response to receiving a pull-in signal. Based on this, the triggering timing of the second switching can be slightly earlier than, synchronized with, or slightly later than the action of cutting off the power supply to the coil 212, and the specific timing can be optimized and adjusted according to requirements and circuit.

[0062] As mentioned earlier, when the switching device 200 needs to be engaged, it is generally desirable for the coil 212 to generate the largest possible electromagnetic force to ensure reliable and rapid closing. According to the electromagnetic force formula, under the same current, the coil 212 with a larger inductance tends to correspond to more ampere-turns and may generate a stronger magnetic field. Therefore, switching the coil 212 to a first connection topology with high equivalent inductance during the engagement phase is beneficial for establishing a larger current change rate or obtaining a larger steady-state ampere-turns under a given drive voltage, which may accelerate the engagement process or enhance the closing holding force.

[0063] The second switching, together with the first switching, enables bidirectional reconfigurability of coil 212 throughout the entire lifecycle of switching device 200, improving the overall performance and flexibility of the device. Based on this, the embodiments of this application can dynamically configure the optimal inductance state of coil 212 according to different requirements for engagement and disengagement, enabling the switching device 200 to achieve performance improvements in different operating stages. This further expands the application value of the variable topology coil 212 technology of this application, allowing it not only to optimize the disengagement response of switching device 200, but also, under the premise of optimized disengagement response, to further ensure that the speed of engagement response is not affected.

[0064] In this application embodiment, there is no specific limitation on the first connection topology state and the second connection topology state of the coil 212, as long as the equivalent inductance of the coil 212 in the first connection topology state is greater than the equivalent inductance of the coil 212 in the second connection topology state.

[0065] In one implementation, coil 212 may include multiple winding segments. A first connection topology of coil 212 may involve all windings of coil 212 connected to the circuit, while a second connection topology may involve only a portion of the windings connected to the circuit, with the remaining windings short-circuited or open-circuited. For example, coil 212 may include two winding segments connected in series. In the first connection topology, these two winding segments are connected in series to the driving circuit of coil 212 to form a substrate capable of generating or transforming electromagnetic fields. In the second connection topology, one of these winding segments is connected in series to the driving circuit of coil 212 to form a substrate capable of generating or transforming electromagnetic fields, while the other segment is short-circuited or open-circuited to avoid involvement in electromagnetic control. In this case, assuming the inductance of the two winding segments is the same, the equivalent inductance of coil 212 in the second connection topology is half that in the first connection topology.

[0066] In another implementation, coil 212 comprises multiple winding segments. A first connection topology involves these segments connected in series, while a second connection topology involves all winding segments connected in parallel. Each winding segment can be understood as coil 212 being divided into multiple winding segments that can be electrically connected or combined independently. In the first connection topology, all winding segments are connected in series, and the equivalent inductance of coil 212 is the sum of the equivalent inductances of each individual winding segment. In the second connection topology, all winding segments are connected in parallel, and the equivalent inductance of coil 212 decreases geometrically compared to the first connection topology. The equivalent inductance of each winding segment can be the same or different.

[0067] To facilitate understanding and explanation, let's take the example of multiple winding segments having the same equivalent inductance to illustrate why the equivalent inductance of coil 212 in the second connection topology decreases dramatically in a geometric progression. When the inductance values ​​of each winding segment are the same and tightly coupled (e.g., coupling coefficient k≈1), after multiple winding segments are connected in parallel, the equivalent inductance of coil 212 is 1 / N² of the equivalent inductance of coil 212 when multiple winding segments are connected in series. Here, N is the number of winding segments, that is, coil 212 is divided into N equal winding segments. For example, when N=3, when all 3 winding segments are connected in parallel, the equivalent inductance of coil 212 is approximately 1 / 9 of the equivalent inductance of coil 212 when all 3 winding segments are connected in series.

[0068] This is because the formula for calculating the inductance L of coil 212 is as follows.

[0069] (1) Where N is the number of turns in the winding, and S is the cross-sectional area of ​​coil 212. Let l be the permeability of the magnetic core and l be the length of coil 212. According to formula (1), if coil 212 is divided into N winding segments, the inductance L1 of each segment becomes 1 / N of L. 2 .

[0070] To ensure consistent magnetic field distribution in both series and parallel configurations of the multi-segment windings and to simplify the manufacturing process, in some embodiments, the multiple windings forming coil 212 are wound on the same iron core; that is, N windings are wound on the same iron core. For example, Figure 3 The three winding segments L1, L2, and L3 shown are wound on the same iron core. This arrangement clearly defines the physical spatial relationship between the multiple winding segments. They are not independent inductors, but are tightly wound on the same iron core, which allows for very strong magnetic coupling between the winding segments, with a coupling coefficient k close to 1, thus making the winding segments approximately fully coupled to each other.

[0071] Given that coil 212 is configured as a multi-segment winding wound on the same iron core, mutual inductance M can exist between any two segments of the winding. Based on a coupling coefficient of 1, the mutual inductance M between them is L / 9. Figure 3 When the three windings L1, L2, and L3 shown are connected in series, the equivalent inductance of coil 212 is... The calculation formula is as follows.

[0072] (2) exist Figure 3 When the three windings L1, L2, and L3 shown are connected in parallel, the equivalent inductance of coil 212 is... The calculation formula is as follows.

[0073] (3) Wherein, L refers to the coil 212 as a whole in the prior art (i.e. Figure 1 The inductance of coil 212 in the middle, The equivalent inductance of coil 212 in the first connection topology state, L1 represents the equivalent inductance of coil 212 in the second connection topology. L1 is the self-inductance of a single-segment winding, and 2M is the mutual inductance on the single-segment winding. The coil 212 in the first connection topology can be understood as dividing the existing integral coil 212 into three winding segments connected in series to form coil 212. The coil 212 in the second connection topology can be understood as dividing the existing integral coil 212 into three winding segments connected in parallel to form coil 212.

[0074] Based on the above formulas (2) and (3), it can be further concluded that after multiple winding segments are connected in parallel, the equivalent inductance of the coil 212 formed by this connection is approximately 1 / N of the equivalent inductance of the coil 212 formed by multiple winding segments connected in series. 2 Because the time constant τ = L / R for current decay in coil 212, the decay time can be drastically reduced as the equivalent inductance L decreases, thus allowing the current to decrease rapidly. Based on this, mechanical switch 210 can quickly disconnect.

[0075] It should be noted that the number of segments N in the multi-segment winding in this embodiment is not limited to 3, but can be 2, 4, 5 or more. The more segments there are, the greater the difference in inductance between the series and parallel states, but the more complex the switching circuit 213 becomes. A trade-off can be made based on the requirements for breaking speed and circuit cost.

[0076] By setting the first connection topology and the second connection topology, the equivalent inductance of coil 212 can decrease sharply in a geometric series when disconnected, thus providing a basis for extremely significant electromagnetic parameter changes for rapid disconnection, thereby further improving the response speed of rapid disconnection of switching device 200.

[0077] As mentioned earlier, the switching circuit 213 is used to switch the connection topology of the coil 212, specifically to switch the coil 212 between a first connection topology and a second connection topology. When the first connection topology consists of multiple winding segments connected in series, and the second connection topology consists of multiple winding segments connected in parallel, how to configure the switching circuit 213 to achieve reliable switching between the first and second connection topologies becomes a further problem that needs to be solved.

[0078] As one possible implementation, the switching circuit 213 may include multiple switching switches, which are connected to multiple winding segments. The multiple switching switches have a first on / off state and a second on / off state. When the multiple switching switches are in the first on / off state, the coil 212 is in a first connection topology state; when the multiple switching switches are in the second on / off state, the coil 212 is in a second connection topology state.

[0079] The on / off states of multiple switches can be understood as the overall combination configuration of a group of switches (i.e., multiple switches) under specific control logic, rather than referring to the independent action of a single switch. Based on this, the first on / off state includes a set of instructions for each switch among the multiple switches. The second on / off state includes another set of instructions for each switch among the multiple switches. Each instruction in the instruction set represents whether the corresponding switch is on or off.

[0080] When multiple switching switches are in the first on / off state, the combinational logic of the switch group is configured to connect the multiple windings inside coil 212 into a series circuit. In this state, a specific switching switch closes to connect the beginning and end of each winding segment. Physically, this means that the current must flow sequentially through the first winding segment, the second winding segment, and so on until the last winding segment, with a single path and no current splitting.

[0081] When multiple switching switches are switched to the second on / off state, the combinational logic of the switch group changes, reconfiguring the multiple winding segments into a parallel circuit. In this state, the operation of the switching switches cuts off the series path between the windings and connects the two ends of each winding segment in parallel. Physically, this manifests as the current being shunted when entering node 212 of coil, flowing through each winding segment, and then converging and flowing out.

[0082] By setting multiple switching switches connected to the multi-segment winding, and controlling the switching of multiple switching switches between the first on / off state and the second on / off state, an easy-to-implement and reliable hardware foundation is provided for the switching of the connection topology of coil 212. This not only helps to improve the breaking response speed, but also improves the switching reliability between breaking control and engaging control, as well as the overall response speed.

[0083] It should be noted that the specific number of switching switches in the switching circuit 213 is different from the specific number of winding segments in the coil 212. A switching switch can be understood as a controlled switching device, or a controllable switch. For example, a switching switch can include, but is not limited to, MOSFETs or IGBTs. Furthermore, it is understood that for multi-segment winding structures, there are various layout methods for multiple switching switches to achieve the aforementioned series-parallel switching.

[0084] To better understand the multiple toggle switches mentioned above, the following will combine... Figure 3 This will be explained. See details. Figure 3 Coil 212 is divided into three identical winding segments, namely, coil 212 includes three winding segments L1, L2, and L3. These three winding segments are connected to six switching switches S1-S6, which constitute the switching circuit 213 described earlier. For specific connection details, please refer to [reference needed]. Figure 3 .

[0085] The first on / off states of the six switching switches S1-S6 are: S1 on, S2 on, S3 off, S4 off, S5 off, and S6 off. Based on this first on / off state, L1, L2, and L3 are connected in series, meaning coil 212 is in the first connection topology. At this time, when there is a normal current in coil 212 used to drive the mechanical contact 211 to close, the current path is: positive power supply terminal in+ of coil 212 - L1 - S1 - L2 - S2 - L3 - negative power supply terminal in- of coil 212.

[0086] The second on / off states of the six switching switches S1-S6 are: S1 off, S2 off, S3 on, S4 on, S5 on, and S6 on. Based on this second on / off state, L1, L2, and L3 are connected in parallel, that is, coil 212 is in the second connection topology. At this time, when there is a current in coil 212 that is normally used to drive the mechanical contact 211 to close, the current path is: positive power supply terminal in+- of coil 212, L1, L2, and L3- negative power supply terminal in- of coil 212.

[0087] Figure 3 The proposed solution can reliably and quickly perform topology reconfiguration of coil 212 by electronically controlling multiple switching switches, providing robust and flexible hardware support for the switching of the topology connection state of coil 212.

[0088] To prevent the generation of electric arcs during the breaking process of the mechanical contact 211, thereby protecting the mechanical contact 211 and avoiding breaking delays caused by arc extinguishing, in some embodiments, the switching device 200 in this application embodiment can be a hybrid switch formed by both a mechanical switch 210 and a semiconductor switch 220. Specifically, as shown in the example... Figure 4 As shown, the switching device 200 also includes a semiconductor switch 220. The semiconductor switch 220 is connected in parallel with the mechanical contact 211. The semiconductor switch 220 can be a fully or partially controlled switch, such as a thyristor (SCR), an insulated gate bipolar transistor (IGBT), a metal-oxide-semiconductor field-effect transistor (MOSFET), or an integrated gate commutated thyristor (IGCT).

[0089] In this embodiment, the semiconductor switch 220 is turned on in response to receiving an open or closed signal. The turned-on semiconductor switch 220 provides a low-impedance bypass path for the load current during the dynamic process of the mechanical contact 211 opening or closing, thereby transferring the load current from the mechanical contact 211 branch to the semiconductor switch 220 branch. Based on this, the voltage across the mechanical contact 211 can be clamped at the on-state voltage drop level of the semiconductor switch 220 (typically 1.5V-2V), making the voltage across the mechanical contact 211 much lower than the arcing voltage (hundreds of volts) in air or other media. Based on this, arc-free opening or closing can be achieved. When the switching device 200 is in a stable on-state, the mechanical contact 211 is closed. Since its contact resistance is much lower than the on-state resistance of the semiconductor switch 220, most of the load current flows through the mechanical contact 211, and the semiconductor switch 220 is in the off-state, generating almost no losses.

[0090] In one possible implementation, the semiconductor is controlled by a control unit configured to, in response to receiving an interruption signal, control the semiconductor switch 220 to turn on and control the switching circuit 213 to perform a first switching. The turning on of the semiconductor switch 220 and the first switching can be performed simultaneously, or the first switching can occur slightly later than the turning on of the semiconductor switch 220. By first conducting the transfer current through the semiconductor switch 220, a zero-voltage or low-voltage condition is created for the separation of the mechanical contacts 211. Simultaneously, the first switching can transform the connection topology of the coil 212 to a second connection topology, and the sudden drop in equivalent inductance allows the mechanical contacts 211 to separate rapidly. After the mechanical contacts 211 are completely separated, the semiconductor switch 220 is turned off, ultimately achieving the interruption of the switching device 200.

[0091] By adding a semiconductor switch 220 in parallel with the mechanical contact 211, the two key advantages of fast breaking (achieved by the variable topology coil 212) and arc-free breaking (achieved by the bypass of the semiconductor switch 220) can be combined. Therefore, the arcing caused by the mechanical switch 210 when breaking large currents can be avoided, thus extending the breaking time for arc extinguishing. Combined with the concept of accelerating contact breaking by reducing the decay time constant of this application, fast and damage-free breaking is achieved. It also takes into account fast and seamless switching and low steady-state loss, so that the seamless switching time (or the breaking process time) is much less than 10ms.

[0092] In some embodiments, the control unit is further configured to: in response to receiving a pull-in signal, control the semiconductor switch 220 to turn on and control the switching circuit 213 to perform a second switching. The turning on of the semiconductor switch 220 and the second switching can be performed simultaneously, or the second switching can occur slightly later than the turning on of the semiconductor switch 220. By first conducting the transfer current through the semiconductor switch 220, a zero-voltage or low-voltage condition is created for the pull-in of the mechanical contact 211. Simultaneously, the second switching can transform the connection topology of the coil 212 to the first connection topology, and the increased equivalent inductance allows the mechanical contact 211 to have sufficient electromagnetic attraction. After the mechanical contact 211 is fully pulled in, the semiconductor switch 220 is turned off, ultimately achieving the pull-in of the switching device 200.

[0093] The formula for calculating the electromagnetic attraction force F is as follows.

[0094] (4) Where N is the number of turns in the winding, and I is the current in coil 212. Based on the above formula (4), it can be seen that the attraction scheme in this embodiment will not reduce the electromagnetic force of coil 212, and the attraction speed of mechanical switch 210 is consistent with the attraction speed in the prior art. This further solves the problem of contact arc erosion during rapid attraction and ensures the electromagnetic attraction force and attraction speed during attraction.

[0095] To surpass the natural attenuation limit imposed solely by reducing the equivalent inductance, the demagnetization process of coil 212 is further accelerated to further speed up the breaking response. This application proposes accelerating the demagnetization process by applying a reverse voltage to the positive power supply terminal in+ and the negative power supply terminal in- of coil 212. The reverse voltage can be understood as the voltage between the positive and negative power supply terminals in+ and in- of coil 212 having a positive polarity and a negative polarity. When the equivalent inductance of coil 212 is known, applying a reverse voltage to the power supply terminals of coil 212 generates a very large negative current change rate, thereby forcing the current in coil 212 to decrease rapidly. This allows the magnetic field energy to be forcibly reduced faster than the previously described scheme, further improving the breaking response speed of the switching device 200.

[0096] As one implementation, the reverse voltage can be a reverse drive voltage provided by a voltage conversion circuit 214 connected between the drive circuit of coil 212 and the power supply terminal of coil 212. Therefore, in some embodiments, such as... Figure 5 and Figure 6 As shown, the switching device 200 also includes a voltage conversion circuit 214. The voltage conversion circuit 214 is connected between the driving circuit and the power supply terminal of the coil 212. Specifically, the input terminal of the voltage conversion circuit 214 is connected to the output terminal of the driving circuit to receive the driving voltage provided by the driving circuit, and the output terminal of the voltage conversion circuit 214 is connected to the power supply terminal of the coil 212. The power supply terminal of the coil 212 may include a positive power supply terminal in+ and a negative power supply terminal in-. The first and second output terminals of the voltage conversion circuit 214 are respectively connected to the positive power supply terminal in+ and the negative power supply terminal in-. The driving circuit is a power supply circuit used to provide the driving voltage to the coil 212. It is understood that... Figure 5 and Figure 6 The driving circuit is not shown; only the driving voltage Uc provided at the output terminal of the driving circuit is shown. The voltage conversion circuit 214 is used to reverse the polarity of the driving voltage Uc to obtain a converted driving voltage, and is used to provide the converted driving voltage to the power supply terminal of the coil 212. This application embodiment does not specifically limit the topology of the voltage conversion circuit 214; any conversion circuit topology capable of outputting bidirectional voltage is acceptable. For example, the voltage conversion circuit 214 can be an H-bridge circuit or a half-bridge circuit.

[0097] The transformed driving voltage includes: forward driving voltage, reverse driving voltage, or zero-value driving voltage. The forward driving voltage is used to drive the mechanical contact 211 to engage. The forward driving voltage can be understood as the voltage between the positive power supply terminal in+ and the negative power supply terminal in- of coil 212, where the positive power supply terminal in+ is positive and the negative power supply terminal in- is negative. The reverse driving voltage is the driving voltage with the opposite polarity to the forward driving voltage; that is, the reverse driving voltage can be understood as the voltage between the positive power supply terminal in+ and the negative power supply terminal in- of coil 212, where the negative power supply terminal in- is positive and the positive power supply terminal in+ is negative. The reverse driving voltage can accelerate the decay of the current in coil 212. A zero-value driving voltage can be understood as a driving voltage with a voltage value of 0. When the transformed driving voltage is a zero-value driving voltage, it is equivalent to stopping the power supply to the power supply terminal of coil 212, that is, stopping the driving.

[0098] In this embodiment, by adding a more powerful voltage conversion circuit 214 to the switching device 200, it can not only provide a forward driving voltage to the coil 212 to energize and engage the mechanical contact 211, but also provide a reverse driving voltage or a zero-value driving voltage. This allows the mechanical contact 211 to be opened in natural freewheeling mode after the coil 212 is de-energized according to the zero-value driving voltage during disconnection, or the mechanical contact 211 to be opened in accelerated freewheeling mode by energizing the coil 212 according to the reverse driving voltage during disconnection. Based on this, when the switching device 200 disconnects, it can flexibly choose between natural freewheeling mode or accelerated freewheeling mode for demagnetization. Furthermore, in accelerated freewheeling mode, no additional voltage source is required; the reverse voltage can be provided through the voltage conversion circuit 214, thus effectively reducing the cost of implementing the reverse voltage.

[0099] Since a voltage conversion circuit 214 can be provided in the switching device 200, in some embodiments, in order to enable the control unit to flexibly manage the operating mode of the voltage conversion circuit 214 and achieve fine control of the disconnection and engagement processes, the switching device 200 also includes a control unit (…). Figures 5-6 (Not shown in the diagram) The voltage conversion circuit 214 is connected to the control unit, which is configured to perform the following control modes: in response to receiving an interruption signal, the voltage conversion circuit 214 is controlled to provide a zero-value drive voltage or a reverse drive voltage to the power supply terminal of the coil 212; or, in response to receiving an engagement signal, the voltage conversion circuit 214 is controlled to provide a forward drive voltage to the power supply terminal of the coil 212.

[0100] In response to receiving the disconnection signal, the control voltage conversion circuit 214 provides a zero-value driving voltage to the power supply terminal of the coil 212, which is equivalent to demagnetizing by relying on natural freewheeling in the prior art. In other words, it is equivalent to disconnecting the power supply to the coil 212.

[0101] Furthermore, the control strategy during the aforementioned disconnection can be fixed or adaptive. For example, a zero-voltage mode can be used to reduce stress during light-load disconnection, while a reverse voltage mode can be used to pursue maximum speed during heavy-load or emergency fault disconnection.

[0102] It is understandable that the control voltage conversion circuit 214 provides a zero-value driving voltage or a reverse driving voltage to the power supply terminal of the coil 212 in sync with or slightly later than the control switching circuit 213 described above, which reduces the equivalent inductance of the coil 212. The former provides a reverse driving voltage to the power supply terminal of the coil 212 to actively apply reverse voltage to accelerate demagnetization, while the latter actively reduces the time constant to accelerate demagnetization. Through the synergy of the two, the breaking response speed can be doubled.

[0103] By adopting a scheme in which the control unit flexibly selects the driving voltage mode according to instructions, not only is the disconnection response speed further improved, but also the drive for engagement is not affected, so as to adapt to different application requirements and working conditions, achieve optimized configuration of performance and cost, and enhance the universality of the application of this embodiment.

[0104] In the embodiments of this application, the control unit mentioned can be understood as a hardware, software, or firmware entity capable of receiving instruction signals, performing logic processing, and outputting control signals. For example, the control unit may include, but is not limited to, a microcontroller, a digital signal processor, a programmable logic device, or a control circuit built from discrete logic circuits.

[0105] As mentioned earlier, the voltage conversion circuit 214 can be an H-bridge circuit, which will be discussed below. Figure 5 and Figure 6 The topology of the voltage conversion circuit 214 as an H-bridge circuit and the corresponding control strategy are illustrated by example. Figure 5 and Figure 6As shown, the voltage conversion circuit 214 includes a first bridge arm and a second bridge arm connected in parallel. The first bridge arm includes a first power device and a second power device connected in series, and the second bridge arm includes a third power device and a fourth power device connected in series. Both ends of the first and second bridge arms can be connected to a driving voltage. The midpoint of the first bridge arm is connected to the positive power supply terminal in+ of the coil 212, and the midpoint of the second bridge arm is connected to the negative power supply terminal in- of the coil 212. The midpoints of the first and second bridge arms form the output terminals of the voltage conversion circuit 214. Specifically, the first end of the first power device is connected to the positive terminal of the driving voltage, the first end of the second power device is connected to the negative terminal of the driving voltage, and the second ends of the first and second power devices are connected at the midpoint of the first bridge arm. The first end of the third power device is connected to the positive terminal of the driving voltage, the first end of the fourth power device is connected to the negative terminal of the driving voltage, and the second ends of the third and fourth power devices are connected at the midpoint of the second bridge arm.

[0106] In some embodiments, such as Figure 5 As shown, the first power device, the second power device, the third power device, and the fourth power device are all controllable switches. Specifically, the first power device, the second power device, the third power device, and the fourth power device are respectively... Figure 5 The controllable switches are SW1, SW2, SW3 and SW4.

[0107] In other embodiments, such as Figure 6 As shown, the first and fourth power devices are both controllable switches, while the second and third power devices are both diodes. Specifically, the first, second, third, and fourth power devices are respectively... Figure 5 The controllable switch SW1, diode D2, diode D3, and controllable switch SW4 are included.

[0108] The controllable switch can be a MOSFET or an IGBT. It should be noted that, compared to... Figure 5 By setting the second and third power devices as diodes, it is possible to further reduce costs and improve reliability while still achieving the same ability to provide forward and reverse drive voltages.

[0109] Optionally, a current-limiting resistor R1 can be connected between the positive power supply terminal in+ of coil 212 and the midpoint of the first bridge arm (e.g., ...). Figure 5 and Figure 6 As shown), and / or, a current-limiting resistor R1 can be connected between the negative power supply terminal in- of coil 212 and the middle of the second bridge arm. By setting the current-limiting resistor R1, current can be limited and the demagnetization speed can be accelerated.

[0110] In view of the fact that the voltage conversion circuit 214 can be configured as the H-bridge circuit described above, the control unit can be specifically configured to perform one of the following control methods: control the first power device and the fourth power device to be turned on and the second power device and the third power device to be turned off, so that the voltage conversion circuit 214 provides a positive drive voltage to the power supply terminal of the coil 212; control the first power device and the third power device to be turned on and the second power device and the fourth power device to be turned off, so that the voltage conversion circuit 214 provides a zero-value drive voltage to the power supply terminal of the coil 212; control the second power device and the fourth power device to be turned on and the first power device and the third power device to be turned off, so that the voltage conversion circuit 214 provides a zero-value drive voltage to the power supply terminal of the coil 212; control the second power device and the third power device to be turned on and the first power device and the fourth power device to be turned off, so that the voltage conversion circuit 214 provides a reverse drive voltage to the power supply terminal of the coil 212.

[0111] By setting the voltage conversion circuit 214 as the H-bridge circuit described above and setting the control strategy of the control unit as described above, it is possible to generate a positive drive voltage, a reverse drive voltage, and turn off the power supply between the positive power supply terminal in+ and the negative power supply terminal in- of the coil 212 by controlling the on / off combination of the four power devices in the H-bridge circuit.

[0112] The preceding text described in detail how the reverse voltage applied to the power supply terminal of coil 212 is the reverse drive voltage provided by voltage conversion circuit 214. The embodiments of this application are not limited to this method of providing the reverse voltage. As another implementation, the reverse voltage can be provided by a negative voltage circuit 215 connected in the freewheeling circuit of coil 212. The following describes, in conjunction with... Figures 7-9 This will be explained in detail.

[0113] like Figure 7 and Figure 9 As shown, the switching device 200 further includes a freewheeling diode D1 and a negative voltage circuit 215. The freewheeling diode D1 is connected to the coil 212 to form a freewheeling circuit. Specifically, the anode of the freewheeling diode D1 is connected to the negative power supply terminal in- of the coil 212, and the cathode of the freewheeling diode D1 is connected to the positive power supply terminal in+ of the coil 212, thus forming a freewheeling circuit. Optionally, a current-limiting resistor R1 can also be provided on the freewheeling circuit. The freewheeling resistor can be set between the cathode of the freewheeling diode D1 and the positive power supply terminal in+ of the coil 212, such as... Figure 7 and Figure 9As shown. Alternatively, the freewheeling resistor can be placed between the anode of the freewheeling diode D1 and the negative power supply terminal in- of the coil 212. The negative voltage circuit 215 is placed in the freewheeling circuit. Specifically, the negative voltage circuit 215 is placed between the anode of the diode and the negative power supply terminal in- of the coil 212. The negative voltage circuit 215 is configured to provide a reverse voltage to the power supply terminal of the coil 212 in response to the disconnection of the power supply terminal of the coil 212 from the drive circuit. Specifically, the disconnection of the power supply terminal of the coil 212 from the drive circuit can be in response to the drive control switch K1 (e.g., ...). Figure 7 and Figure 9 )disconnect.

[0114] Based on this setup, when the power supply to coil 212 is cut off (e.g., the drive circuit stops outputting voltage, i.e.) Figure 7 and Figure 9 When the driving voltage Uc is 0, and the current in coil 212 needs to freewheel, the current no longer simply decays naturally through the freewheeling diode D1. Instead, an additional reverse voltage drop is generated in the freewheeling circuit of coil 212 through the negative voltage circuit 215. The polarity of this reverse voltage drop is opposite to the original driving voltage of coil 212, thus achieving an effect similar to active reverse drive, accelerating current decay. Although this method requires a separate negative voltage circuit 215, its control of the driving voltage is relatively simpler and compatible with the existing circuit structure that controls the on / off state of the driving circuit through a drive control switch, potentially reducing the complexity of providing the reverse voltage.

[0115] This application does not impose specific limitations on the topology of the negative voltage circuit 215, as long as the negative voltage circuit 215 can provide a negative voltage to the power supply terminal of the coil 212 when the driving circuit does not provide a driving voltage.

[0116] In one implementation, the negative voltage circuit 215 may include a voltage source. The voltage source may have a positive output terminal and a negative output terminal. The positive output terminal may be connected to the negative power supply terminal in- of the coil 212, and the positive output terminal may be connected to the positive power supply terminal in+ of the coil 212. At least the aforementioned freewheeling diode D1 is disposed between the positive output terminal and the positive power supply terminal in+ of the coil 212. Based on this arrangement, when the power supply terminal of the coil 212 is disconnected from the drive circuit, the voltage source can provide a voltage UO between the negative power supply terminal in- and the positive power supply terminal in+ of the coil 212; this voltage is the reverse voltage.

[0117] A voltage source can be understood as an active circuit element capable of establishing and maintaining a specific potential difference between its positive and negative output terminals. For example, a voltage source can be a battery, auxiliary power supply, or charge pump circuit. In some embodiments, a voltage source can provide a fixed reverse voltage. In other embodiments, a voltage source can provide an adjustable reverse voltage; that is, it is an adjustable voltage source.

[0118] By providing reverse voltage through an external voltage source, different voltage levels can be flexibly selected according to actual needs. Furthermore, if the voltage source is adjustable, the specific reverse voltage magnitude can be selected even more flexibly based on the actual application scenario or load, resulting in faster demagnetization and increased flexibility.

[0119] As mentioned earlier, in some embodiments, the magnitude of the reverse voltage provided by the voltage source is adjustable. As one implementation method, such as... Figure 8 As shown, the voltage source may include a transformer and multiple upper capacitors (capacitors C11-C1n in the figure), multiple diodes, and multiple lower capacitors (C21-C2n) connected to the secondary side of the transformer. The voltage on the primary side of the transformer is U. i The voltage on the secondary side of the transformer is U2. By adjusting the specific number of capacitors n connected to the secondary side, the output voltage U of the voltage source can be changed. O The magnitude of the reverse voltage. Specifically, the relationship between the reverse voltage and n is as follows.

[0120] (5) Through the above, as shown Figure 8 The voltage source shown not only allows for adjustable reverse voltage output, but also provides a higher level of reverse voltage with only a few components. It is also easily expandable and allows for convenient adjustment of the voltage source's level.

[0121] As another implementation, the negative voltage circuit 215 may include a voltage clamping device. In this embodiment, the voltage clamping device can provide a reverse voltage to the power supply terminal of the coil 212 when the power supply terminal of the coil 212 is disconnected from the driving circuit, utilizing a clamping principle. For example, the voltage clamping device can be a transient voltage suppressor diode (TVS) or a varistor (MOV). The number of voltage clamping devices in the negative voltage circuit 215 can be one or more. When there are multiple voltage clamping devices, a higher reverse voltage can be provided to the power supply terminal of the coil 212, thereby accelerating the demagnetization speed and further improving the breaking response speed. As an example, such as... Figure 9As shown, the negative voltage circuit 215 includes two transient voltage suppression diodes. By using a voltage clamping device as the negative voltage circuit 215, reverse voltage application can be achieved with a very simple device, which has the advantages of low cost, fast response and high reliability.

[0122] This embodiment of the application breaks through the physical response limit of the traditional mechanical switch 210: by reconfiguring the excitation coil 212 from series to parallel at the moment of disconnection, the inductance time constant is significantly reduced, and with the active reverse voltage forcing the magnetic flux to return to zero in a very short time, rapid physical separation of the mechanical contact 211 is achieved. Simultaneously, combined with the bypass shunt technology of the semiconductor switch 220, the voltage across the mechanical contact 211 is clamped to near zero during the disconnection process, achieving arc-free "cold switching," completely solving the problem of electrical erosion and extending its lifespan. This solution perfectly integrates the low steady-state loss of the mechanical switch 210 with the high-speed control characteristics of power electronic devices, meeting the stringent requirements of power supply systems for storing sensitive loads and switching off-grid with a low-cost, high-reliability innovative architecture.

[0123] In addition, this application embodiment also provides a power supply system 10. The power supply system 10 mentioned in this application embodiment can be an energy storage system, a photovoltaic-energy storage system, or a photovoltaic-energy storage-charging system. For example... Figure 10 As shown, the power supply system 10 includes a power converter 300 and the aforementioned switching device 200. The power converter 300 is connected to an external circuit via the switching device. The external circuit can be understood as a circuit located outside the power converter 300 and required to be connected to it.

[0124] In some embodiments, the power converter 300 can be a DC power converter, with its input and output both connected to a DC power supply or a load. The input can be connected to a DC power supply and / or the output via a switching device 200, and / or the output can be connected to a DC power supply or a load via a switching device.

[0125] In other embodiments, the power converter 300 can be one or more of the following: an inverter with bidirectional energy transfer capability, a power conversion system (PCS), and a rectifier with bidirectional energy transfer capability. Based on this, the switching device 200 can be understood as a grid-connected / off-grid switching unit. Specifically, the power converter 300 can include an AC terminal and a DC terminal. The DC terminal is used to connect to a DC power supply or a DC load, and the AC terminal is connected to an AC circuit, such as a public power grid, via the switching device 200. In this environment, one end of the switching device 200 is connected to the power grid, and the other end is connected to the AC terminal of the power converter 300. The mechanical switch 210 in the switching device 200 can be an AC circuit breaker. When the power grid is normal, the switch device 200 is closed and the power converter 300 operates in parallel with the grid. When a grid fault is detected (such as voltage drop, frequency abnormality, short circuit, etc.), the control unit needs to control the switch device 200 to reliably disconnect from the grid in a very short time (e.g., less than 5 milliseconds) based on the disconnection signal and through the above-described method in the embodiments of this application, so that the power converter 300 can seamlessly switch to off-grid operation mode and provide uninterrupted power supply to critical loads.

[0126] The above text combined Figures 1 to 10 The device embodiments of this application have been described in detail below, in conjunction with... Figure 11 The method embodiments of this application are described in detail below. It should be understood that the description of the method embodiments corresponds to the description of the apparatus embodiments; therefore, any parts not described in detail can be referred to the foregoing apparatus embodiments.

[0127] The control method for the switching device provided in this application is used to control the switching device described above. As mentioned earlier, the switching device includes a mechanical switch and a switching circuit. The mechanical switch includes mechanical contacts, a coil, and a switching circuit. The coil controls the mechanical contacts to close or open based on electromagnetic control, and the switching circuit is connected to the coil.

[0128] like Figure 11 As shown, the control method includes step S1110. In step S1110: in response to receiving an interruption signal, the switching circuit is controlled to switch the equivalent inductance of the coil. The equivalent inductance of the coil after switching is less than the equivalent inductance of the coil before switching.

[0129] In some embodiments, the coil has a first connection topology and a second connection topology, and the equivalent inductance of the coil in the second connection topology is less than its equivalent inductance in the first connection topology; step S1110 includes: in response to receiving a disconnection signal, controlling the switching circuit to switch the coil from the first connection topology to the second connection topology.

[0130] In some embodiments, the control method further includes: in response to receiving an engagement signal, controlling the switching circuit to switch the coil from a second connection topology state to a first connection topology state.

[0131] In some embodiments, the coil includes multiple winding segments, with a first connection topology in which the multiple winding segments are connected in series and a second connection topology in which the multiple winding segments are all connected in parallel.

[0132] In some embodiments, the switching circuit includes a plurality of switching switches connected to a plurality of winding segments. The plurality of switching switches have a first on / off state and a second on / off state. When the plurality of switching switches are in the first on / off state, the coil is in a first connection topology state. When the plurality of switching switches are in the second on / off state, the coil is in a second connection topology state.

[0133] In some embodiments, multiple windings are wound on the same iron core.

[0134] In some embodiments, the switching device further includes a semiconductor switch connected in parallel with the mechanical contacts, and the control method further includes: controlling the semiconductor switch to turn on in response to receiving an open signal or an closed signal.

[0135] In some embodiments, the switching device further includes a voltage conversion circuit connected between the driving circuit and the power supply terminal of the coil. The voltage conversion circuit is used to provide a converted driving voltage to the power supply terminal of the coil. The converted driving voltage includes a forward driving voltage, a reverse driving voltage, or a zero-value driving voltage. The control method further includes: in response to receiving an interruption signal, controlling the voltage conversion circuit to provide a zero-value driving voltage or a reverse driving voltage to the power supply terminal of the coil; or, in response to receiving an engagement signal, controlling the voltage conversion circuit to provide a forward driving voltage to the power supply terminal of the coil.

[0136] In some embodiments, the voltage conversion circuit includes a first bridge arm and a second bridge arm connected in parallel. The first bridge arm includes a first power device and a second power device connected in series, and the second bridge arm includes a third power device and a fourth power device connected in series. Both ends of the first and second bridge arms are connected to a driving voltage. The midpoint of the first bridge arm is connected to the positive power supply terminal of the coil, and the midpoint of the second bridge arm is connected to the negative power supply terminal of the coil. The first and fourth power devices are both controllable switches, and the second and third power devices are both controllable switches or diodes. The voltage conversion circuit controls the power supply to the coil. Providing a forward drive voltage includes: controlling the first power device and the fourth power device to be turned on and the second power device and the third power device to be turned off; controlling the voltage conversion circuit to provide a zero-value drive voltage to the power supply terminal of the coil includes: controlling the first power device and the third power device to be turned on and the second power device and the fourth power device to be turned off, or controlling the second power device and the fourth power device to be turned on and the first power device and the third power device to be turned off; controlling the voltage conversion circuit to provide a reverse drive voltage to the power supply terminal of the coil includes: controlling the second power device and the third power device to be turned on and the first power device and the fourth power device to be turned off.

[0137] In some embodiments, the switching device further includes a freewheeling diode and a negative voltage circuit. The anode of the freewheeling diode is connected to the negative power supply terminal of the coil, and the cathode of the freewheeling diode is connected to the positive power supply terminal of the coil. The negative voltage circuit is disposed between the anode of the freewheeling diode and the negative power supply terminal of the coil. The control method further includes: in response to the disconnection of the power supply terminal of the coil from the driving circuit, providing a reverse voltage to the power supply terminal of the coil through the negative voltage circuit.

[0138] This application also provides a controller that can be used to execute the methods described in the above method embodiments. This application does not limit the specific implementation of the controller. For example, the controller can be implemented in hardware when executing the above methods. Alternatively, the controller can be implemented using a combination of software and hardware. Yet another example is that the controller can be implemented in software, such as by an MCU running a computer program to execute the above methods.

[0139] This application also provides a chip, including a processor, which can be used to call and run a computer program from memory, causing a power converter or power system on which the chip is installed to perform the methods described in the above method embodiments. It is understood that the processor can be any type of processor mentioned above. It is also understood that the memory can be independent of the chip or integrated into the chip.

[0140] This application also provides a machine-readable storage medium for storing a program. This program causes a computer to execute the methods described in the various embodiments of this application.

[0141] This application also provides a computer program product. The computer program product includes a program. The program causes a computer to perform the methods described in various embodiments of this application.

[0142] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any other combination. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this disclosure are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a machine-readable storage medium or transmitted from one machine-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The machine-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., digital video discs (DVDs)), or semiconductor media (e.g., solid-state drives (SSDs)).

[0143] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments of this disclosure can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this disclosure.

[0144] In the several embodiments provided in this disclosure, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0145] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0146] In addition, the functional units in the various embodiments of this disclosure can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0147] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A switching device, characterized in that, include: A mechanical switch includes mechanical contacts, a coil, and a switching circuit. The coil controls the mechanical contacts to close or open based on electromagnetic control. The switching circuit is connected to the coil. In response to receiving a disconnection signal, the switching circuit switches the equivalent inductance of the coil. The equivalent inductance of the coil after switching is less than the equivalent inductance of the coil before switching.

2. The switching device according to claim 1, characterized in that, The coil has a first connection topology and a second connection topology. The equivalent inductance of the coil in the second connection topology is less than the equivalent inductance of the coil in the first connection topology. In response to receiving the disconnection signal, the switching circuit switches the coil from the first connection topology to the second connection topology.

3. The switching device according to claim 2, characterized in that, In response to receiving an engagement signal, the switching circuit switches the coil from the second connection topology state to the first connection topology state.

4. The switching device according to claim 2, characterized in that, The coil includes multiple winding segments. The first connection topology is that the multiple winding segments are connected in series, and the second connection topology is that the multiple winding segments are all connected in parallel.

5. The switching device according to claim 4, characterized in that, The switching circuit includes multiple switching switches connected to the multiple winding segments. The multiple switching switches have a first on / off state and a second on / off state. When the multiple switching switches are in the first on / off state, the coil is in the first connection topology state. When the multiple switching switches are in the second on / off state, the coil is in the second connection topology state.

6. The switching device according to claim 4, characterized in that, The multiple winding segments are wound on the same iron core.

7. The switching device according to any one of claims 1-6, characterized in that, Also includes: A semiconductor switch, connected in parallel with the mechanical contacts, turns on in response to receiving the disconnection signal or the activation signal.

8. The switching device according to claim 1, characterized in that, Also includes: A voltage conversion circuit is connected between the driving circuit and the power supply terminal of the coil. The voltage conversion circuit is used to provide a converted driving voltage to the power supply terminal of the coil. The converted driving voltage includes: a forward driving voltage, a reverse driving voltage, or a zero-value driving voltage.

9. The switching device according to claim 8, characterized in that, The switching device further includes a control unit, and the voltage conversion circuit is connected to the control unit. The control unit is configured to perform the following control methods: In response to receiving the disconnect signal, the voltage conversion circuit is controlled to provide the 0-value driving voltage or the reverse driving voltage to the power supply terminal of the coil; or, In response to receiving a pull-in signal, the voltage conversion circuit is controlled to provide the positive drive voltage to the power supply terminal of the coil.

10. The switching device according to claim 9, characterized in that, The voltage conversion circuit includes a first bridge arm and a second bridge arm connected in parallel. The first bridge arm includes a first power device and a second power device connected in series. The second bridge arm includes a third power device and a fourth power device connected in series. Both ends of the first bridge arm and the second bridge arm are connected to a driving voltage. The midpoint of the first bridge arm is connected to the positive power supply terminal of the coil, and the midpoint of the second bridge arm is connected to the negative power supply terminal of the coil. The control unit is configured to perform one of the following control methods: The first power device and the fourth power device are turned on while the second power device and the third power device are turned off, so that the voltage conversion circuit provides the positive drive voltage to the power supply terminal of the coil; The first power device and the third power device are controlled to be turned on while the second power device and the fourth power device are turned off, so that the voltage conversion circuit provides the 0-value drive voltage to the power supply terminal of the coil; The second power device and the fourth power device are controlled to be turned on while the first power device and the third power device are turned off, so that the voltage conversion circuit provides the 0-value drive voltage to the power supply terminal of the coil; The second power device and the third power device are controlled to be turned on while the first power device and the fourth power device are turned off, so that the voltage conversion circuit provides the reverse drive voltage to the power supply terminal of the coil; In this configuration, the first power device and the fourth power device are both controllable switches, and the second power device and the third power device are both controllable switches or diodes.

11. The switching device according to claim 1, characterized in that, Also includes: A freewheeling diode, wherein the anode of the freewheeling diode is connected to the negative power supply terminal of the coil, and the cathode of the freewheeling diode is connected to the positive power supply terminal of the coil, so as to form a freewheeling circuit; A negative voltage circuit is disposed between the anode of the freewheeling diode and the negative power supply terminal of the coil. The negative voltage circuit is configured to provide a reverse voltage to the power supply terminal of the coil in response to the disconnection of the power supply terminal of the coil from the driving circuit.

12. The switching device according to claim 11, characterized in that, The negative voltage circuit includes a voltage source, which has a positive output terminal and a negative output terminal. The positive output terminal is connected to the negative power supply terminal of the coil, and the negative output terminal is connected to the anode of the freewheeling diode.

13. The switching device according to claim 12, characterized in that, The reverse voltage provided by the voltage source is adjustable.

14. The switching device according to claim 11, characterized in that, The negative voltage circuit includes a voltage clamping device.

15. A control method for a switching device, characterized in that, The switching device includes a mechanical switch, which includes mechanical contacts, a coil, and a switching circuit. The coil controls the mechanical contacts to close or open based on electromagnetic control. The switching circuit is connected to the coil. The control method includes: In response to receiving a disconnection signal, the switching circuit is controlled to switch the equivalent inductance of the coil, and the equivalent inductance of the coil after switching is less than the equivalent inductance of the coil before switching.

16. The control method according to claim 15, characterized in that, The coil has a first connection topology and a second connection topology, and the equivalent inductance of the coil in the second connection topology is less than its equivalent inductance in the first connection topology. The step of controlling the switching circuit to switch the equivalent inductance of the coil in response to receiving a disconnection signal includes: In response to receiving the disconnection signal, the switching circuit is controlled to switch the coil from the first connection topology state to the second connection topology state.

17. The control method according to claim 16, characterized in that, Also includes: In response to receiving a pull-in signal, the switching circuit is controlled to switch the coil from the second connection topology state to the first connection topology state.

18. The control method according to any one of claims 15 to 17, characterized in that, The switching device further includes a semiconductor switch connected in parallel with the mechanical contacts, and the control method further includes: In response to receiving the disconnect signal or the engage signal, the semiconductor switch is controlled to turn on.

19. The control method according to claim 15, characterized in that, The switching device further includes a voltage conversion circuit, which is connected between the driving circuit and the power supply terminal of the coil. The voltage conversion circuit is used to provide a converted driving voltage to the power supply terminal of the coil. The converted driving voltage includes: a forward driving voltage, a reverse driving voltage, or a zero-value driving voltage. The control method further includes: In response to receiving the disconnect signal, the voltage conversion circuit is controlled to provide the 0-value driving voltage or the reverse driving voltage to the power supply terminal of the coil; or, In response to receiving a pull-in signal, the voltage conversion circuit is controlled to provide the positive drive voltage to the power supply terminal of the coil.

20. The control method according to claim 19, characterized in that, The voltage conversion circuit includes a first bridge arm and a second bridge arm connected in parallel. The first bridge arm includes a first power device and a second power device connected in series. The second bridge arm includes a third power device and a fourth power device connected in series. Both ends of the first bridge arm and the second bridge arm are connected to a driving voltage. The midpoint of the first bridge arm is connected to the positive power supply terminal of the coil, and the midpoint of the second bridge arm is connected to the negative power supply terminal of the coil. The first power device and the fourth power device are both controllable switches, and the second power device and the third power device are both controllable switches or diodes. The control of the voltage conversion circuit to provide the positive drive voltage to the power supply terminal of the coil includes: controlling the first power device and the fourth power device to be turned on and the second power device and the third power device to be turned off; The method of controlling the voltage conversion circuit to provide the 0-value driving voltage to the power supply terminal of the coil includes: controlling the first power device and the third power device to be turned on and the second power device and the fourth power device to be turned off, or controlling the second power device and the fourth power device to be turned on and the first power device and the third power device to be turned off; The control of the voltage conversion circuit to provide the reverse drive voltage to the power supply terminal of the coil includes: controlling the second power device and the third power device to be turned on and the first power device and the fourth power device to be turned off.

21. The control method according to claim 15, characterized in that, The switching device further includes a freewheeling diode and a negative voltage circuit. The anode of the freewheeling diode is connected to the negative power supply terminal of the coil, and the cathode of the freewheeling diode is connected to the positive power supply terminal of the coil. The negative voltage circuit is disposed between the anode of the freewheeling diode and the negative power supply terminal of the coil. The control method further includes: In response to the disconnection of the power supply terminal of the coil from the drive circuit, a reverse voltage is provided to the power supply terminal of the coil through the negative voltage circuit.

22. A controller, characterized in that, Used to perform the control method as described in any one of claims 15-21.

23. A power supply system, characterized in that, include: The switching device as described in any one of claims 1-14; A power converter, which is connected to an external circuit via the switching device.

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