Switching system

Abstract

The present invention proposes a switching system (500, 600, 700) comprising: a mechanical switch (210) for current, including a conductive state and a non-conductive state; a first actuator (100) configured to change the state of the mechanical switch, wherein the actuation of the first actuator is based on a Thomson coil system; and a second actuator (510) configured to change the state of the mechanical switch (210), including a loading spring system locked by a latching system; wherein the first actuator (100) and the second actuator (510) are each configured to change the state of the mechanical switch (210) according to the characteristics of the current passing through the mechanical switch (210).

Description

Technical Field

[0001] This invention relates to a switching system, including an actuator based on a Thomson coil system and a spring system. Background Technology

[0002] Thomson coil systems represent a class of fast actuators developed for switching operations. A Thomson coil system typically comprises a flat coil with conductive plates parallel to the flat coil itself. Current flowing through the coil generates a magnetic field, introducing eddy currents into the plates, thereby producing a large repulsive electromagnetic force that can be used for actuation. In particular, in switching applications, these forces are used to rapidly separate the contacts of a mechanical switch. The coil of a Thomson coil system can be driven by active or passive electronic circuitry.

[0003] The idea behind the actuator based on a passive Thomson coil is to trigger it using the energy of the fault current, specifically by directly using the rate of change of the fault current, dI / dt, to generate motion of the conductive plate. Therefore, this method helps reduce the delay between fault initiation and the separation of the mechanical switch contacts. Consequently, the acceleration of the conductive plate is a function of the rate of change of the current, dI / dt. Summary of the Invention

[0004] This means that when the rate of change of current dI / dt is very slow (<1kA / ms), as happens in the case of overload current, the force acting on the conductive plate is insufficient to push it into the disconnected position. Figure 3 Experimental values ​​and Figure 4 The simulation shown illustrates this point: the larger dI / dt is, the faster the given gap distance is reached.

[0005] Therefore, a switching system is needed that can rapidly switch from a conductive state to a non-conductive state for high current change rates dI / dt, but also rapidly switch from a high current with low current change rates to a non-conductive state.

[0006] The basic idea of ​​this invention is to combine a passive Thomson coil-based actuator, which is essentially used for high current change rates dI / dt (typically >1kA / ms), with a spring system, which is essentially used for low current change rates dI / dt (typically <1kA / ms).

[0007] Various aspects of the present invention relate to a switching system and the use of the switching system, the subject of which is described in the independent claims.

[0008] Advantageous modifications of the invention are set forth in the dependent claims. All combinations of at least two features disclosed in the specification, claims, and drawings fall within the scope of the invention. To avoid repetition, the features disclosed according to this method should also be applicable and may be applied according to the system.

[0009] Throughout this description of the invention, some features are provided for counting words to improve readability or make the assignment clearer, but this does not mean that certain features exist.

[0010] To achieve these and other advantages, and in accordance with the purposes of the invention, as embodied and broadly described herein, a switching system is provided comprising a mechanical switch for current, including a conductive state and a non-conductive state. The switching system further comprises a first actuator configured to change the state of the mechanical switch, wherein actuation of the first actuator is based on a Thomson coil system. The switching system further comprises a second actuator configured to change the state of the mechanical switch, comprising a loading spring system locked by a latching system, and wherein the first and second actuators are each configured to change the state of the mechanical switch according to the characteristics of the current flowing through the mechanical switch.

[0011] According to one aspect, the mechanical switch is mechanically coupled to the first actuator and / or the second actuator.

[0012] According to one perspective, the Thomson coil system is a passive Thomson coil system. This means that the Thomson coil system is based on a passive Thomson coil.

[0013] The dependence on current characteristics for changing the state of a mechanical switch can be achieved by configuring a first actuator based on a Thomson coil system that changes the state of the mechanical switch according to the rate of change of current (dI / dt), and can also be configured a second actuator that changes the state of the mechanical switch according to a threshold of the current passing through the mechanical switch.

[0014] In other words, if the first actuator is based on a passive Thomson coil system, its actuation depends on the rate of change of current, dI / dt. If dI / dt is too slow, the Thomson coil system has difficulty disconnecting the mechanical switch. Therefore, for large rates of change of current, dI / dt, a loaded spring actuator is provided, which responds more slowly than the first actuator based on the passive Thomson coil system.

[0015] Thomson coil systems represent a class of fast actuators developed for switching operations. For example... Figure 1 As shown, it includes a flat coil with conductive plates parallel to the coil. The current flowing through the coil generates a magnetic field, introducing eddy currents into the plates, thereby producing a large repulsive electromagnetic force that can be used for actuation. In particular, in switching applications, these forces are used to quickly separate the contacts of mechanical circuit breakers. Actuators based on Thomson coils may exhibit greater... Figure 1 The simple sketch shows a more complex structure.

[0016] The switching system provides the contact breaking speed based on a first actuator using a Thomson coil system, according to a high rate of change of current dI / dt. The second actuator, based on a spring-loaded system, where its actuation depends on the amount of current independent of the rate of change of current dI / dt, provides the mechanical switch's state change, including the slower rate of change of current dI / dt due to the spring system. The breaking speed of the spring-loaded system is a function of the spring stiffness, the space and tolerances between the moving parts, and the mass of the moving parts. For a properly designed system, this can be rapid, resulting in the spring system achieving a 1mm breaking gap for the mechanical switch within approximately 2ms.

[0017] Advantageously, the switching system described above can switch to a non-conductive state relative to the full spectrum of fault currents, which is very fast for large current change rates dI / dt, and can also switch to a non-conductive state during overcurrent, which allows more time (some ms) for the response.

[0018] This switching system, which combines two different actuators, provides a system to handle fault currents as well as smaller overcurrents, and the required switching system includes manual operation functionality, thereby avoiding the need for additional switches and saving the space and cost associated with additional switches for manual operation.

[0019] The latching system for locking the loaded spring system can be easily constructed using different possible unlocking mechanisms, and the switching system can be configured to be additionally locked in the open, non-conductive position.

[0020] If the spring system is designed to achieve a 1mm break gap within approximately 2ms, then from Figure 3 It can be seen that for large dI / dt, the Thomson plate will actuate first as expected, and then the slower spring system will still "quickly" hold the contacts in the fully open position.

[0021] Advantageously, a fast-disconnect switching system for high current change rates dI / dt can rapidly interrupt fault current in a DC system based on a Thomson coil system, and additionally allows coordination with other protective devices (e.g., fuses). However, a loaded spring actuator can successfully handle slower current change rates dI / dt, such as overcurrent.

[0022] According to one aspect, the mechanical switch includes: a first conductor configured to be at a first potential; a second conductor configured to be at a second potential; and a conductive bridge, wherein the conductive bridge is configured to be in electrical contact with the first and second conductors in a conductive state, and not in electrical contact with at least one of the conductors in a non-conductive state.

[0023] The conductive bridge can be separated from the first and second conductors, and / or the conductive bridge can be part of one of the conductors. This means that the conductive bridge can move on its own and / or the conductive bridge can be continuously electrically and mechanically connected to one of the contacts.

[0024] In other words, a mechanical switch can be, for example, a mechanical switch having a fixed contact and a movable contact that are parallel to each other, but includes all other types of mechanical switches.

[0025] For example, if the actuator is triggered by current through a mechanical switch and thereby disconnects the electrical contact between the first and second conductors, the first and second actuators can be coupled to a conductive bridge to increase the distance between the conductive plate and the first and / or second conductors.

[0026] Advantageously, the mechanical switches of the switching system can have a simple construction.

[0027] According to one aspect, the conductive bridge is held in a conductive state by a closing spring.

[0028] This closed spring can provide force for the solid electrical contact between the conductive bridge and the corresponding conductor of the mechanical switch.

[0029] According to one aspect, the first actuator is configured to change the conductive state of the mechanical switch when the rate of change of the current through the mechanical switch exceeds the current change limit.

[0030] A change in the conductive state of a mechanical switch can be a change from a conductive state to a non-conductive state. The change in the conductive state of the mechanical switch by a first actuator can be provided by mechanical coupling of the first actuator to the mechanical switch. As an example, the first actuator can be mechanically coupled to a conductive plate to increase the distance between the conductive bridge and at least one of the conductors, thereby switching the mechanical switch from a conductive state to a non-conductive state.

[0031] Since the first actuator is based on a Thomson coil system, it provides sensitivity to the rate of change of current.

[0032] Advantageously, no sensors are needed to provide this functionality of the first actuator.

[0033] According to one aspect, the current through the mechanical switch passes through the Thomson coil of the Thomson coil system to drive the first actuator of the mechanical switch to change its state.

[0034] Passing current through a Thomson coil to a mechanical switch provides a simple actuation system.

[0035] According to one aspect, the second actuator is configured to change the state of the mechanical switch if the current flowing through it exceeds a current limit. This means that if the current flowing through the mechanical switch exceeds a current threshold, the second actuator will change the state of the mechanical switch due to its configuration.

[0036] In this way, the switching system can accommodate fault currents with low current change rates but where the current through the mechanical switch exceeds the current limit.

[0037] According to one aspect, the latching system of the second actuator is configured to unlock the loading spring if the current through the mechanical switch exceeds the current value limit.

[0038] Thus, if the loading spring is released by unlocking the latch according to the amount of current, the second actuator can interact with the mechanical switch to change from a conductive state to a non-conductive state.

[0039] This provides the advantage that no electrical energy from the circuit system is required in order to switch the state of the mechanical switch itself.

[0040] According to one aspect, the latching system includes a bimetallic strip, wherein the latching system is configured to at least partially allow current passing through the mechanical switch to pass through the bimetallic strip to unlock the loading spring if the current exceeds a current value limit.

[0041] Bimetallic strips are used to convert temperature changes into mechanical displacement. The strip consists of two different metal strips that expand at different rates when heated, such as steel and copper and / or steel and brass. This differing expansion forces the flat strip to bend unidirectionally when heated and in the opposite direction when cooled below its initial temperature. When the strip is heated, the metal with the higher coefficient of thermal expansion is on the outside of the curve, while when the strip cools, the metal is on the inside. Passing a current exceeding the current limit through the bimetallic strip will increase its temperature.

[0042] This bimetallic strip provides a simple construction for the latching system to lock the loaded spring.

[0043] According to one aspect, the latching system includes a magnetic shape memory alloy system and an electromagnetic coil, wherein the latching system is configured to at least partially allow current from a mechanical switch that alters the shape of the magnetic shape memory alloy system to pass through the electromagnetic coil to unlock the loading spring if the current exceeds a current value limit.

[0044] Magnetic shape memory alloys (MSMs) change their shape under the influence of an external magnetic field and can include NiMnGa. This MSM system, combined with an electromagnetic coil, provides a simple and reliable latching system to hold a loaded spring in a locked position and release the spring when a magnetic field is applied to the MSM.

[0045] Alternatively, the electromagnetic coil of the latching system that changes the shape of the shape memory alloy can be supplied with current, wherein the latching system is configured to supply current through the electromagnetic coil based on the measurement results of a current measuring sensor that measures the current passing through the mechanical switch.

[0046] On one hand, latching systems are based on electromechanical systems.

[0047] Such an electromechanical system could be, for example, an electrical relay. This means that the loading spring of the second actuator can be locked by the electromechanical system, which is configured to release the loading spring if at least a portion of the current and / or a current proportional to the current through the mechanical switch passes through the electromechanical system to release the loading spring when the current through the electromechanical system exceeds a certain limit.

[0048] According to one aspect, the latching system includes a current measuring sensor that measures the current passing through the mechanical switch, wherein the latching system is configured to release the loading spring if the current passing through the mechanical switch exceeds a current value limit.

[0049] According to one aspect, current measurement sensors include shunts and / or Rogowski coils and / or Hall sensors.

[0050] The sensor provides a simple and reliable method for measuring current.

[0051] According to one aspect, the first actuator and the second actuator are configured to each push or alternatively pull the contact bridge of the mechanical switch to change the state of the mechanical switch to a non-conductive state.

[0052] Advantageously, this provides a wide range of construction possibilities for switching systems.

[0053] This means that the first actuator and the second actuator can be configured to push or, alternatively, pull the contact bridge. This means that one actuator can push the contact bridge while the other can pull it, or both can be actuated in the same way by pushing or pulling the contact bridge, thereby changing the state of the mechanical switch to a non-conductive state.

[0054] According to one aspect, the first actuator and / or the second actuator of the switching system described above are configured to manually and / or remotely change the state of the mechanical switch based on a trigger signal, thereby affecting the first actuator and / or the second actuator.

[0055] The trigger signal can be an electrical signal that affects the first actuator and / or the second actuator.

[0056] This means that, in addition to the aforementioned release mechanism, the switching system can be configured to be manually opened or closed by means of changes in current rate or current above a certain current limit, for example by manually releasing the loading spring to open the mechanical switch and / or by manually loading the spring to close the mechanical switch.

[0057] Alternatively, the switching system can be configured to disconnect remotely based on a trigger signal, for example by remotely releasing a load spring, to disconnect the mechanical switch using a latching system that can be configured to release the load spring based on a trigger signal.

[0058] Alternatively, the switching system can be configured to close remotely based on a trigger signal, for example by remotely loading a spring of a second actuator to close the mechanical switch using an electromechanical system, which can be configured to load the spring based on a trigger signal.

[0059] Manual and / or remote control of the switching system allows the mechanical switches of the switching system to be disconnected and / or connected as part of the contactor circuit.

[0060] Provided for use in a switching system as described above for protecting battery energy storage systems and / or electric vehicles and / or electric vehicle chargers or data centers in the event of fault current and / or short-circuit current and / or overload current.

[0061] Switching systems can be used to protect battery energy storage systems, but they can also be used in applications such as data centers and / or electric vehicle charging systems. Applications of the switching systems described can relate to low-voltage and medium-voltage switching, respectively.

[0062] To explain the second actuator of the aforementioned switching system (including the loading spring system locked by the latching system) in more detail, it is compared here with a different second actuator that is not part of the switching system described in this specification. This different second actuator may be based on an electromechanical system configured to directly alter the state of the mechanical switch. This means that if the current through the mechanical switch exceeds a current limit, the electromechanical system can be configured and mechanically coupled to the mechanical switch to force the mechanical switch into the open position.

[0063] Thus, the switching system with the first actuator is configured to change the state of the mechanical switch based on a Thomson coil system, and a different second actuator can be based on an electromechanical system, such that, without a loaded spring, the second actuator is configured to force the mechanical switch into the off position. For example, the electromechanical system can disconnect the mechanical switch by using a magnetic field to move a magnetic device mechanically coupled to the mechanical switch from a first position to a second position.

[0064] Alternatively or additionally, different second actuators can be configured to change the state of the mechanical switch by a trigger signal to close the mechanical switch accordingly. Attached Figure Description

[0065] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. The drawings show:

[0066] Figure 1 This is a schematic representation of an actuator based on a Thomson coil;

[0067] Figure 2 This is a diagram illustrating a possible implementation of an actuator based on a passive Thomson coil;

[0068] Figure 3 This is the experimental stroke curve of the conductive plate of the actuator based on the Thomson coil;

[0069] Figure 4 The travel curves of the conductive plate of the Thomson coil-based actuator for different dI / dt were determined through simulation calculations.

[0070] Figure 5 This is a schematic diagram of an example of a switching system;

[0071] Figure 6a , Figure 6b This is a schematic diagram of another example of a switching system drawn from different perpendicular directions;

[0072] Figure 7a , Figure 7b This is another example of a switching system drawn from different perpendicular directions. Detailed Implementation

[0073] Figure 1 A schematic representation of an actuator 100 based on a Thomson coil is shown. The magnetic field generated by the current flowing through the flat coil 110 induces eddy currents inside the conductive plate 120. The resulting repulsive electromagnetic force F causes the plate to move away from the coil.

[0074] Figure 2The passive implementation is schematically depicted. A Thomson coil system 100, as part of a first actuator, has a coupling 230 between the Thomson coil system and a mechanical switch 210. The mechanical switch 210 includes a first conductor 212, a second conductor 214, and a conductive bridge 220.

[0075] Figure 3 Figure 300 is provided, showing experimental travel curves 310, 312, 314, 316, and 318 of the moving conductive plate 120 of the Thomson coil-based actuator 100.

[0076] The rate of change of current, dI / dt, ranges from 1 to 21 kA / ms (1 kA / ms: (318), 3 kA / ms: (316), 7 kA / ms: (314), 15 kA / ms: (312), 21 kA / ms: (310)). Clearly, the slower dI / dt, the slower the acceleration of the conductive plate, and the longer the time required to reach the endpoint (between 1 and 1.5 mm in this example). For the measurement shown, the contact is locked in the open position.

[0077] Figure 4 Figure 400 shows the travel curves of the moving plate of the Thomson coil-based actuator at different current change rates dI / dt determined by simulation calculations (200kA / ms:(410), 10kA / ms:(412), 5kA / ms:(414), 2.5kA / ms:(416), 1kA / ms:(418)).

[0078] Figure 5 A schematic diagram depicting an example of a switching system 500 is provided.

[0079] As described above Figure 5 The passive Thomson coil system in Figures 6 and 7, and the spring system with Figure 1 Start describing.

[0080] Figure 5 Figures 6 and 7 illustrate the concept of combining a Thomson coil-based system 100 (including coil 110 and conductive plate 120) with a spring system 510. For a large current change rate dI / dt, the Thomson plate 120 actuates rapidly and disconnects the conductive bridge 220. At a slow current change rate dI / dt where the Thomson coil-based system 100 is less efficient, the loading spring system 510 pushes the Thomson plate 120 to disconnect the conductive bridge 220 after the loading spring system 510 is unlocked via a latching system. The conductive plate spring 520 can provide the necessary contact force for the conductive bridge 220 in the closed position. The mechanical connection between the Thomson conductive plate 120 and the spring system 510 should be loose, i.e., the Thomson conductive plate 120 can move independently of the loading spring 510.

[0081] Switching systems 500, 600, and 700 can be configured to clamp the push rail in the end position or maintain it in the open position via a release spring system 510 that directly ensures unlocking. It can be noted that the first actuator based on the Thomson coil system 100 can have a higher... Figure 1 More complex geometry or shapes in a simple schematic diagram.

[0082] pass Figure 5 In the configuration of the switching system 500, a loading spring 510 can be pushed onto the Thomson conductive plate 120. In the presence of a large current change rate dI / dt, the Thomson conductive plate 120 breaks the conductive path between the first conductor 212 and the second conductor 214 provided by the conductive bridge 220 of the mechanical switch 210, while the loading spring 510 can follow after a few milliseconds, i.e., without contributing to the breaking of the conductive path. In the case of slow breaking, due to the small current change rate, the released, unlocked loading spring 510 pushes the Thomson conductive plate 120 until the desired gap is reached.

[0083] The mechanical connection between the Thomson conductive plate 120 and the spring system 510 may be loose, meaning that the Thomson conductive plate 120 can move independently of the spring system 510. A latching system is not shown here.

[0084] The contact spring 520 can provide the required force to maintain the conductive bridge 220 in mechanical and electrical contact with the first conductor 212 and the second conductor 214.

[0085] Figure 6a and Figure 6b A schematic diagram depicting another example of a switching system 600 drawn from different side view directions perpendicular to each other. A first actuator including a Thomson coil system 100 and a spring system 520 (not shown here) is shown. Figure 5 The example of the described switching system 500 is similar.

[0086] The main difference between the switching systems 600 and 500 is that the spring system 510, indicated by the force arrow 510, is mechanically coupled to the conductive bridge 220 via the push rail 610.

[0087] The push rail 610 is guided within the slit (not shown here). The spring system is not shown, but can be placed in three dimensions.

[0088] Figure 7a , Figure 7b A schematic diagram depicts another example of a switching system 700 drawn from different side view directions perpendicular to each other. This example of the switching system 700 is similar to the configuration shown in Figure 6, except that the Thomson conductive plate pulls the contacts apart instead of pushing them.

Claims

1. A switching system (500, 600, 700), comprising: Mechanical switches (210) for current, including conductive and non-conductive states; A first actuator (100) is configured to change the state of the mechanical switch, wherein the actuation of the first actuator is based on a Thomson coil system; The second actuator (510) is configured to change the state of the mechanical switch (210), including a loading spring system locked by a latching system; The first actuator (100) and the second actuator (510) are each configured to change the state of the mechanical switch (210) according to the characteristics of the current passing through the mechanical switch (210); The switching system is configured to change the state by driving the first actuator (100) of the mechanical switch (210) to change the state by passing the current through the Thomson coil (110) of the Thomson coil system.

2. The switching system (500, 600, 700) according to claim 1, wherein the mechanical switch (210) comprises: The first conductor (212) is configured to be at a first potential; The second conductor (214) is configured to be at a second potential; as well as The conductive bridge (220) is configured to make electrical contact with the first conductor (212) and the second conductor (214) in the conductive state; and is configured not to make electrical contact with at least one of the conductors (212, 214) in the non-conductive state.

3. The switching system (500, 600, 700) according to claim 2, wherein the conductive bridge (220) is held in the conductive state position by a contact spring (520).

4. The switching system (500, 600, 700) according to any one of claims 1 to 3, wherein the first actuator (100) is configured to change the conductivity state of the mechanical switch (210) if the rate of change of the current through the mechanical switch (210) exceeds the rate of change limit of the current.

5. The switching system (500, 600, 700) according to any one of claims 1 to 3, wherein the second actuator (510) is configured to change the state of the mechanical switch (210) if the amount of current through the mechanical switch (210) exceeds a current value limit.

6. The switching system (500, 600, 700) according to any one of claims 1 to 3, wherein the latching system of the second actuator (510) is configured to unlock the loading spring if the amount of current through the mechanical switch (210) exceeds a current value limit.

7. The switching system (500, 600, 700) according to any one of claims 1 to 3, wherein the latching system comprises a bimetallic strip, wherein the latching system is configured to, in the event that the current exceeds a current value limit, at least partially allow the current through the mechanical switch to pass through the bimetallic strip to unlock the loading spring.

8. The switching system (500, 600, 700) according to any one of claims 1 to 3, wherein the latching system comprises a magnetic shape memory alloy system and an electromagnetic coil, wherein the latching system is configured to at least partially allow the current through the mechanical switch (210) to pass through the electromagnetic coil, which alters the shape of the magnetic shape memory alloy system, to unlock the loading spring if the current exceeds a current value limit.

9. The switching system (500, 600, 700) according to any one of claims 1 to 3, wherein the latching system includes a current measuring sensor that measures the current through the mechanical switch (210), wherein the latching system is configured to unlock the loading spring if the current through the mechanical switch (210) exceeds a current value limit.

10. The switching system (500, 600, 700) according to claim 9, wherein the current measuring sensor comprises a shunt and / or a Rogowski coil and / or a Hall sensor.

11. The switching system (500, 600, 700) according to any one of claims 1 to 3, wherein the latching system is based on an electromechanical system.

12. The switching system (500, 600, 700) according to any one of claims 1 to 3, wherein the first actuator (100) and the second actuator (510) each push or alternately pull the contact bridge (220) of the mechanical switch (210) to change the state of the mechanical switch (210) to the non-conductive state.

13. The switching system (500, 600, 700) according to any one of claims 1 to 3, wherein the first actuator and / or the second actuator is configured to manually and / or remotely change the state of the mechanical switch (210) based on a trigger signal affecting the first actuator (100) and / or the second actuator (510).

14. Use of the switching system (500, 600, 700) according to any one of the preceding claims in protecting battery energy storage systems and / or electric vehicles and / or electric vehicle chargers or data centers in the event of fault current and / or short-circuit current and / or overload current.

Images