阅读说明：本技术 通过切换两个串联连接的开关来持久断开带有感性负载的电路的方法和装置 (Method and device for permanently disconnecting an electric circuit with an inductive load by switching two switches connected in series ) 是由 P·莱尔 于 2020-02-05 设计创作，主要内容包括：本发明涉及一种通过切换两个串联连接的开关来持久断开带有感性负载的电路的方法和装置。该装置具有第一和第二开关/开关组,它们彼此串联连接,并且可以从闭合状态转换到断开状态以断开电路,没有开关/开关组被设计成使其能够单独地持久断开电路,该装置还具有控制单元,用于控制第二开关/开关组,其被设计成使得第二开关/开关组时间上在第一开关/开关组之后从闭合状态转换到断开状态。本发明还涉及一种电路,该电路除了根据本发明的装置之外,还具有电压源、负载电阻和感性负载,并且还涉及使用根据本发明的装置的方法。(The invention relates to a method and a device for permanently breaking an electric circuit with an inductive load by switching two switches connected in series. The device has a first and a second switch/switch group which are connected in series with one another and can be switched from a closed state to an open state in order to open the circuit, no switch/switch group being designed such that it can permanently open the circuit alone, and a control unit for controlling the second switch/switch group which is designed such that the second switch/switch group is switched from the closed state to the open state temporally after the first switch/switch group. The invention also relates to a circuit having a voltage source, a load resistance and an inductive load in addition to the device according to the invention, and to a method of using the device according to the invention.)

1. A device for breaking an electrical circuit (1) having an inductive load (L), the device having:

(a) a first switch/switch group (S1) and a second switch/switch group (S2), the first switch/switch group (S1) and the second switch/switch group (S2) being connected in series with one another and being able to be switched from a closed state to an open state for opening the electrical circuit (1), none of the switch/switch groups (S1, S2) being designed such that it is individually able to reliably permanently open the electrical circuit (1), and

(b) a control unit (2), the control unit (2) controlling the second switch/switch group (S2) and being designed such that the second switch/switch group (S2) transits from the closed state to the open state temporally after the first switch/switch group (S1).

2. The device according to claim 1, wherein the control unit (2) is designed such that the second switch/switch group (S2) is only transferred from the closed state to the open state at the earliest when so much energy has been absorbed in the first switch/switch group (S1) that the remaining energy introduced into the second switch/switch group (S2) does not cause damage thereto.

3. The device according to claim 1 or 2, wherein the control unit (2) is designed such that the second switch/switch group (S2) at the latest is transferred from the closed state to the open state before the energy introduced into the second switch/switch group (S2) reaches a level that would cause damage thereof.

4. The apparatus of any one of claims 1 to 3, wherein the first switch/switch group (S1) and the second switch/switch group (S2) are actively switchable from the closed state to the open state by a controllable driver (110).

5. The device of any one of claims 1 to 3, wherein the first switch/switch group (S1) is passively transitionable from the closed state to the open state and the second switch/switch group (S2) is actively transitionable from the closed state to the open state by a controllable driver (110) when a certain nominal value of current is exceeded.

6. The device according to claim 4 or 5, wherein the control unit (2) is designed to switch the second switch/switch group (S2) from the closed state to the open state depending on a specific measured current or a specific measured voltage through the first switch/switch group (S1).

7. The device of claim 6, wherein the control unit (2) is designed such that the second switch/switch group (S2) switches from the closed state to the open state when the current through both switch/switch groups (S1, S2) drops to a value in the range of 25% to 40% of the current at the start of opening of the first switch/switch group (S1).

8. The device according to claim 6 or 7, wherein the control unit (2) is designed such that the second switch/switch group (S2) switches from the closed state to the open state when the current through both switch/switch groups (S1, S2) drops to a value in the range of 5% to 15% of the current at the beginning of the opening of the first switch/switch group (S1).

9. The device according to claim 6, wherein the control unit (2) is designed to switch the second switch/switch group (S2) from the closed state to the open state in dependence on a certain measured current drop in the electrical circuit.

10. The device according to any one of claims 1 to 9, wherein more than two switches/switch groups are electrically connected in series and can be controlled one after the other in time.

11. A circuit (1), the circuit (1) having a circuit according to claims 1 to 110, voltage source, load resistance (W)_L) And an inductive load (L).

12. Method for opening a circuit (1) with an inductive load (L) with a first switch/switch group (S1) and a second switch/switch group (S2), the first switch/switch group (S1) and the second switch/switch group (S2) being connected in series with one another and, for opening the circuit (1), being switched from a closed state to an open state, wherein none of the switch/switch groups (S1, S2) is designed such that it can alone reliably permanently open the circuit (1), wherein the second switch/switch group (S2) is switched from the closed state to the open state after the first switch/switch group (S1) over time.

13. The method of claim 12, wherein the second switch/switch group (S2) is only switched from the closed state to the open state at the earliest when so much energy has been absorbed in the first switch/switch group (S1) that the remaining energy introduced into the second switch/switch group (S2) does not cause it to break.

14. Method according to claim 12 or 13, wherein the second switch/switch group (S2) is switched from the closed state to the open state at the latest before the energy introduced into the second switch/switch group (S2) reaches a level that would cause damage thereto.

15. The method of any of claims 12 to 14, wherein the first switch/switch group (S1) and the second switch/switch group (S2) are actively switched from the closed state to the open state by a controllable driver (110).

16. Method according to any of claims 12 to 15, wherein the first switch/switch group (S1) passively switches from the closed state to the open state and the second switch/switch group (S2) actively switches from the closed state to the open state by means of a controllable driver (110) when a certain nominal value of the current is exceeded.

17. The method of claim 15 or 16, wherein the second switch/switch group (S2) is switched from the closed state to the open state in dependence on a specific measured current or a specific measured voltage through the first switch/switch group (S1).

18. The method of claim 17, wherein the second switch/switch group (S2) transitions from the closed state to the open state when the current through both switch/switch groups (S1, S2) drops to a value in the range of 25% to 40% of the current at the beginning of the opening of the first switch/switch group (S1).

19. The method of claim 17 or 18, wherein the second switch/switch group (S2) switches from the closed state to the open state when the current through both switch/switch groups (S1, S2) drops to a value in the range of 5% to 15% of the current at the beginning of the opening of the first switch/switch group (S1).

20. The method of claim 17, wherein the second switch/switch set (S2) transitions from the closed state to the open state according to a particular measured current drop in the circuit.

21. The method of any one of claims 12 to 20, wherein more than two switches/switch sets are electrically connected in series and can be controlled successively in time.

Technical Field

The invention relates to a device for permanently and safely opening an electrical circuit with an inductive load and with a high current at a high voltage. The device has a first and a second switch/switch group which are connected in series with one another and can be switched from a closed state into an open state in order to open the circuit, wherein no switch/switch group is designed such that it can open the circuit individually reliably and permanently, and a control unit for controlling the second switch/switch group and which is designed such that the second switch/switch group is switched from the closed state into the open state after the first switch in terms of time. The invention also relates to a circuit having a voltage source, a load resistance and an inductive load in addition to the device according to the invention, and to a method of using the device according to the invention.

Background

It is generally only possible to open a circuit with a high current at a high voltage if the switch consumes a large amount of energy without being destroyed. Hitherto, switches with an interruption zone in which a fire extinguishing agent is present or on which at least one fire extinguishing agent is present have often been used for this purpose. The extinguishing agent is intended to extinguish, deplete or at least destroy the arc generated after the disconnection of the disconnection zone. The reason for the occurrence of an arc is the energy stored in the form of a magnetic field in the circuit inductance when the current is switched off, which energy is introduced into the switch immediately after switching off. This means that high-energy arcs can occur, especially when breaking an electrical circuit with a highly inductive load. Since most fire extinguishants and plastics contain carbon atoms which decompose in extreme arc heat well above 2000 c and then form a conductive carbon layer upon cooling, the arc heat makes the agent fully or partially conductive. Such a switch can actively or passively cut off the circuit at high supply voltages and high currents, but here the inductance of the circuit to be cut off determines whether the switch is highly insulating after a current interruption and remains insulating or is more or less conductive later on again. The same applies to materials used in switches that contain mainly halides of chlorine or fluorine-in this case a high temperature plasma is still present in the switch after the current has been switched off, the conductivity is still low, but if the plasma is cooled after the circuit has been switched off, the conductivity will be very high. A cooling time of a few milliseconds is sufficient. Although the circuit can be interrupted first with such a switch, a permanent and reliable disconnection cannot be ensured with the high insulation resistance that is always required. The switches currently used are already partly suitable for cutting off voltages of 450V to 850V, which are common in automobiles, and the current in the circuit is up to 20kA at the moment of opening. In the future, however, a voltage of 1250V is expected, and for buses and trucks, even more than 2000V, an off current of up to 30kA is expected, so that previously used switches will not be able to permanently and safely break such a circuit as a single module.

Disclosure of Invention

It is therefore an object of the present invention to provide a possibility to permanently and safely disconnect a circuit with high current and high voltage of a high inductive load, in which case a previous high current high voltage switch would fail. Such a switch should of course be prevented from turning on again shortly after being turned off. It is also intended to prevent the switch from being destroyed by the high continuous current flowing when the insulation resistance is insufficient after the switching process.

The device according to the invention for opening an electric circuit with an inductive load has a first and a second switch/switch group which are connected in series with each other and serve to open the electric circuit, so that the electric circuit can be switched from a closed state to an open state, wherein no switch/switch group is designed to be able to permanently open the electric circuit alone. The device according to the invention furthermore has a control unit which controls the second switch/switch group and is designed in such a way that the second switch/switch group switches from the closed state to the open state after the first switch/switch group.

Hereinafter, the term "switch" represents not only a single switch but also a switch group.

There is also included a plurality of switches/switch sets, in which case more than two switches or switch sets are controlled in succession. The switching principle or protection principle is the same, and for the sake of simplicity only two switches/switch groups are described here.

When the circuit is switched off by the first switch, the energy stored in the inductance of the circuit is introduced into the first switch. This energy causes an arc to be generated between the two separated ends of the opening element of the switch. A large amount of energy is now introduced into the first switch, which will cause the first switch to become conductive again or to be destroyed after the actual opening process. By delaying the switching of the second switch, the energy introduced into the first switch can be reduced, since part of the energy to be consumed is introduced into the second switch, which furthermore also only needs to handle or cope with a switching load which is much lower than the current and the voltage flowing through its connected components when activated. This also allows the circuit to be interrupted before the first switch, which is turned on again, is reestablished by the second switch, which cannot handle the circuit inductance. Each switch cannot by itself cope with the full energy stored in the circuit inductance alone, which would cause the switch to break or turn on again, and thus would not be able to break the circuit permanently and safely. In this way, a circuit with such a high inductive load can be switched off permanently and safely, which is not sufficient with a single switch.

One particular form of controlling or switching two switches/switch sets is to control both switches simultaneously. This will halve the voltage drop across each of the two switches, and thus the energy flowing into the respective switch. If the two switches are identically constructed, the two switches will be loaded in the same manner. For smaller circuit inductances this may still be possible, but for higher circuit inductances there is a risk that the two components are again conductive after disconnection, which is not acceptable at all. Likewise, the high disconnectability of the individual switches cannot be used, since care must be taken about the insulation resistance after disconnection, and the second switch cannot be used only at very low switching loads.

In the case of a temporally offset activation or deactivation, it is also possible to combine different switch types with one another. For example, a switch having a high breaking property at high voltage and high current when activated, such as a so-called power fuse (see fig. 5), may be used as the first switch, whereas a conventional Battery cut-off (Battery cut), which is not capable of high current switching by itself at high voltage, may be used as the second switch in the circuit, since at this point in time, i.e. after the first switch is opened, the second switch only needs to be opened at a low voltage with a small current, without having to use a fire extinguishing agent.

According to the invention, the first switch used is preferably a high-current high-voltage switch, i.e. a circuit with high current at high voltage can be reliably disconnected. Such high-current high-voltage switches can usually reliably and permanently disconnect circuits with currents up to 30kA and voltages up to 2000V. Such high-current high-voltage switches come, for example, from DE 102014107853 a1, DE 102014110825 a1, DE 202015100525U 1, DE 102015112141 a1, DE 102015114279 a1, DE 102015114894 a1, DE 102016124176 a1 and DE 102017123021 a 1. If the switch is a switch bank, the switch bank preferably comprises or consists of a parallel circuit of one or more fuses and a conventional battery disconnector. In this case, a battery disconnector is preferred, for example a battery or cable circuit known for conventional vehicle batteries of up to 56V. Both mentioned systems are suitable for main current cut-off at high switching voltages and high switching currents. The first switching group particularly preferably has a fire extinguishing agent in the interior region of the disconnection element, by the disconnection of which the electrical circuit is disconnected. The extinguishing agent ensures that the switch can absorb higher energy when the circuit is open, since the arc can be used to evaporate the extinguishing agent and decompose it into its individual components. Switches without such extinguishing agents are not suitable for breaking an electric circuit with a high switching voltage and a high switching current. However, as mentioned above, the adverse effect of the chemical conversion of the extinguishing agent into electrically conductive material means that the switch quickly becomes electrically conductive again after a certain energy input after the actual switching-off process.

The fire extinguishing agent may be a solid, powder or liquid medium. The extinguishing agent is preferably a vaporizable medium. The extinguishing agent is preferably a liquid or gel medium which is converted in whole or in part to a gaseous state when the boiling or evaporating temperature is reached. At the same time, the extinguishing agent preferably also has electrically insulating properties, so that the arc can be extinguished after the two separate parts of the disconnection zone have been sufficiently removed and subsequently there is sufficient insulation between the separate contacts to prevent undesired currents. The fire extinguishing agent is preferably an oil, such as a silicone oil with or without a thickener, or a silane or a polysiloxane, such as a hexasilane or pentasilane with little or even better no carbon atom component.

According to the invention, a second switch can be used which only withstands a lower energy input than the first switch, since most of the energy from the circuit inductance has been destroyed in the first switch. Preferably, the second switch is a switch that can reliably and permanently disconnect a circuit with currents up to 100A and voltages up to 100V when activated, and can isolate voltages up to 1000V or 2000V without breaking down after disconnection. Since the high energy of the arc quickly causes its conductivity again in the first switch, the second switch is preferably designed such that its switching delay is in the range of 1ms to 10 ms.

The switching delay refers to the time interval between the first and second switches to open the circuit or to switch from a closed state to an open state. However, it is also conceivable for the second switch to have a greater switching delay if, for example, it has already been activated before an arc occurs in the second switch, but has, for example, only shortly thereafter been changed from the closed state to the open state. The latter is however only possible if the time interval required for safely and permanently breaking the circuit between the switching of the first switch and the second switch can be predetermined on the basis of all parameters of the circuit. The system described for the first switch is equally applicable to the second switch. Furthermore, it is also possible to use conventional battery disconnectors without parallel-connected fuses, since these do not switch the high disconnection currents that occur in the inactive state, but can conduct them well. Furthermore, the second switch only has to switch the current in the range of 0A to 100A after the current has been switched off by the first switch when the switching voltage at the switch contact of the second switch is below 100V. Relays or electromagnetic contactors are not suitable for use as the second switch, since relays or contactors used in the automotive field for normal operating currents (from 400A to 1000A) have exploded at high currents (for example, lithium ion batteries exceeding 10 kA) between 0.5ms and 200ms (here the heavy contactors used on railway tractors are not considered, since they cannot be used in the automotive field for reasons of weight, size and cost).

The high-current high-voltage switch or battery disconnector which can be used according to the invention preferably has a housing which comprises a contact unit/connecting element which defines a current path through the high-current high-voltage switch or battery disconnector and has a first and a second connecting contact and a disconnection region. The contact unit is preferably designed such that it can be supplied with current via the first connecting contact and can be discharged from it via the second connecting contact, and vice versa. The disconnection region is preferably designed such that, when it is disconnected, the current path between the first and second connection contacts is interrupted. The shut-off zone is preferably arranged in the reaction chamber. The reaction chamber is preferably filled with a fire extinguishing agent. If the switch is a high-current high-voltage switch, the contact unit can have or be connected to a push-in reflector (Treibspiegel) which is designed such that it can be moved from an initial position to a final position by the applied pressure, wherein the breaking zone breaks in the final position of the push-in reflector and reaches the insulation distance between the first and second connection contacts.

The arrangement of said series connection by the first and second switches enables to open a circuit with a larger circuit inductance than with only a single switch. The first switch here, when open, absorbs a large part of the magnetic energy stored in the circuit inductance in a dissipative manner, while the second switch only has to receive a small amount of magnetic energy which may still be present in the circuit inductance during this process. Thus, the second switch need not necessarily be a switch with extinguishing agent in the vicinity of its breaking element. However, if a circuit with a very high inductance of the circuit is involved, the second switch should also be a switch with a fire suppressant near its disconnect element for safety reasons. Possible fire extinguishing agents have been described above.

In the case of the switch used according to the invention, an adiabatic system can be considered for the purposes of the invention, since the switching process is so rapid that the heat exchange with the surroundings is negligible at least during the disconnection process.

The characteristic of the first and second switches being designed so as not to enable them to break the circuit individually, permanently and safely, is due to the fact that: the known high-current high-voltage switches become conductive again after the actual switching-off process at very high switching voltages and very high switching currents. According to the invention, a permanent and safe disconnection of the circuit means that one or more switches are permanently isolated/insulated and therefore no longer switched on again.

The device according to the invention can be used not only in AC circuits but also in DC circuits. Thus, although in the case of an ac circuit zero-crossing currents are always encountered, it is never possible to predict when the circuit should be switched off. If switching at maximum current is necessary, a dc current cut-off condition will be approximately assumed.

The break-off element in the switch may be a hollow cylinder or an elongated hollow body with a bottom surface cross-section deviating from a circle, so as to be able to be torn by internal pressure, but may also be designed as a rod-like solid conductor for a so-called battery disconnector, which conductor is interrupted at one or more locations by a piston or a shot. In both cases, materials are mostly used which can become electrically conductive when or after contact with the arc due to a large energy impact, and in most cases fire extinguishing agents are also used.

In one embodiment of the device according to the invention, the control unit is preferably designed such that the second switch is first switched from the closed state to the open state only when sufficient energy has been absorbed in the first switch such that the remaining energy introduced into the second switch does not lead to damage to the second switch.

In one embodiment of the device according to the invention, the control unit is preferably designed such that the second switch is switched from the closed state to the open state at the latest before the energy introduced into the second switch reaches an amount that would cause damage thereof.

According to the invention, a breakdown of the switch can be understood as a break in the switch housing or an explosion of the switch due to the introduced energy and the occurrence of an arc.

In one embodiment of the device according to the invention, the first and second switches can be actively switched from the closed state to the open state by means of a controllable drive. "active" is understood to mean any type of mechanical or pyrotechnic energy (pyrotechnischer energy) which can control the opening of the opening zone (opening element) of the switch. For example, the break-away zone may be broken by a pulling or pushing motion acting. Or with pyrotechnic materials, such as igniters (EED) or micro-explosives, either inside or outside the reaction chamber, in order to be able to bring them into the breaking zone and cause them to break, either by means of a pulling or pushing motion or by means of a shock wave.

In one embodiment of the device according to the invention, the first switch can be passively switched from the closed state to the open state when a certain threshold current strength is exceeded, and the second switch can be actively switched from the closed state to the open state by means of a controllable drive. Such passive activation can be achieved, for example, by melting the material forming the breaking zone, for example, when a certain current level is reached. Passive activation may also be supported by the action of a pyrotechnic igniter, as well as the thermal action of just decomposing substances (e.g., tetraphenyl benzene). It is also possible to attach to one or both of the separate parts of the break-away zone means which further separate the two ends from each other, for example by means of a tensile load which is still active after the break-away zone has broken away. As an example, a tensile load caused by a pretensioned spring may be mentioned here.

In one embodiment of the device according to the invention, the control unit is preferably designed such that it switches the second switch from the closed state to the open state as a function of a specific measurement current or a specific measurement voltage present at the first switch.

In one embodiment of the device according to the invention, the control unit is preferably designed such that the second switch switches from the closed state to the open state when the current through the two switches falls within a range of 25% to 40% of the value at the beginning of the opening of the first switch.

In one embodiment of the device according to the invention, the control unit is preferably designed such that the second switch switches from the closed state to the open state when the current through the two switches falls within a range of 5% to 15% of the value at the beginning of the opening of the first switch.

In one embodiment of the device according to the invention, the control unit is preferably designed such that it switches the second switch from the closed state to the open state in dependence on a specific measured current drop in the circuit.

The invention also relates to a circuit having a voltage source and an inductive load in addition to the device according to the invention. In addition to the inductive load, there may be a load resistance in the circuit. All preferred embodiments or modifications of the device according to the invention are also applicable to the circuit according to the invention.

The invention also relates to a method for opening an electric circuit with an inductive load with a first switch and a second switch, which are connected in series with each other and which open the electric circuit by switching from a closed state to an open state, wherein none of the switches is designed to permanently open the electric circuit alone, and wherein the second switch switches from the closed state to the open state after the first switch.

In one embodiment of the method according to the invention, it is preferred that the second switch is first switched from the closed state to the open state only if a large part of the energy has been absorbed in the first switch without the unabsorbed residual energy introduced into the second switch causing damage thereto.

In one embodiment of the method according to the invention, the second switch is preferably switched from the closed state to the open state at the latest before the energy introduced into the second switch reaches an amount that would cause damage thereto.

In one embodiment of the method according to the invention, the first and second switches are preferably actively switched from the closed state to the open state by a controllable drive.

In one embodiment of the method according to the invention, it is preferred that the first switch passively switches from the closed state to the open state when a certain nominal value is exceeded, and the second switch actively switches from the closed state to the open state by means of a controllable drive. For this purpose, the controllable drive is preferably connected to a control unit which controls the drive and can thus switch the second switch from the closed state to the open state.

In one embodiment of the method according to the invention, it is preferred that the second switch is switched from the closed state to the open state as a function of a specific measurement current or a specific measurement voltage through the first switch.

In one embodiment of the method according to the invention, it is preferred that the second switch is transferred from the closed state to the open state when the value of the current flowing through the two switches falls within a range of 25% to 40% of the current at the start of opening of the first switch.

In one embodiment of the method according to the invention, the control unit is preferably designed such that the second switch switches from the closed state to the open state when the current through the two switches falls within a range of 5% to 15% of the value at the beginning of the opening of the first switch.

In one embodiment of the method according to the invention, the control unit is preferably designed such that it switches the second switch from the closed state to the open state in dependence on a specific measured current drop in the circuit.

The device according to the invention or the circuit according to the invention is preferably used in the method according to the invention. Therefore, all preferred embodiments and modifications described above in connection with the device according to the invention should also be applicable to the method according to the invention. For switching the second switch from the closed state to the open state, a control unit as described above is preferably also used. The same applies as long as the second switch is controlled by the control unit.

Drawings

The invention will now be explained in more detail with reference to the following figures. However, these are merely exemplary in nature and are intended to illustrate the invention by way of example.

Fig. 1 shows a circuit according to the invention with a device according to the invention.

Fig. 2 shows a voltage profile of the capacitor bank over time, a voltage profile across the first switch and a current profile in the entire circuit shortly before and after switching of the first switch in the circuit according to fig. 1.

Fig. 3 shows the variation of the current through a first and a second switch over time, which are connected in series in the circuit according to fig. 1.

Fig. 4a shows an example of a battery disconnector in closed state, which can be used as a second switch or in connection with a fuse connected in parallel as part of the first switch group.

Fig. 4b shows the battery disconnector of fig. 4a in a disconnected state.

Fig. 5 shows an example of a high current high voltage switch, which may be used as the first or second switch.

Detailed Description

Fig. 1 shows a circuit 1 according to the invention with a device according to the invention (first switch S1, second switch S2 and control unit 2). The circuit 1 comprises a voltage source represented by + and-, a first switch S1 and a second switch S2 connected in series with each other, and an inductive load L and a load resistance W_L. Furthermore, a control unit 2 is provided, which evaluates the current distribution through the first switch S1, for example, and generates an ignition signal at the second switch S2 in accordance therewith. In this way, the second switch S2 may transition from the closed state to the open state, whereby the second switch S2 interrupts the circuit 1. The first switch S1 may be actively activated by an ignition signal from the control unit 2, but may also be passively switched by exceeding a certain threshold current. The control unit 2 is designed such that the second switch S2 is only switched when sufficient energy stored in the inductive load L has been dissipated after switching the first switch S1. In this way, it is ensured that, in the event of switching, the energy stored in the inductive load L is distributed between the two switches S1 and S2, so that the circuit can be opened permanently and safely even if the first switch S1 is turned on again from the initial state. The control unit 2 may have a comparator/ignition electronics for evaluating the current curve and generating an ignition signal for the second switch S2. The first switch S1 may be a high current, high voltage switch as shown in fig. 5. However, it may be a battery disconnector as shown in fig. 4a and 4b, to which a fuse is connected in parallel. The second switch S2 may also be a high current, high voltage switch as shown in fig. 5, and it may also be a switch as shown in fig. 4aAnd the battery disconnector shown in fig. 4b, but it is not necessary to connect the fuse in parallel. If the first switch S1 is a high current, high voltage switch, the second switch S2 may be either a high current, high voltage switch or a battery disconnector. If the first switch S1 is a battery disconnector to which a fuse is connected in parallel, it is preferable that the second switch is a battery disconnector. The reason for this is that the second switch generally has to absorb less energy than the first switch, and that for cost reasons a cheaper second switch is used.

Fig. 2 shows a voltage curve 3 of the capacitor bank over time, a voltage curve 4 at the connecting contact of the first switch, and a current curve 5 of the entire circuit shortly before and after switching of the first switch in the circuit according to fig. 1. For this purpose a high current high voltage switch as shown in fig. 5 is used as the first switch. Curve 3 shows the voltage curve of the capacitor bank. The initial voltage of the capacitor bank is 1200V, which drops to 650V during the current flow when the switch starts to open. Curve 4 shows the voltage curve across the current connection of the first switch. Curve 5 shows the current curve of the whole circuit. Time point 6 is the time the first switch was opened under the off condition of 650V and 31 kA. Until the point in time 6 when the first switch is opened, the current in the entire circuit increases (current curve 5). After the start of the disconnection at time point 6, the current in the entire circuit drops sharply. In curve 4 (voltage curve over the first switch), after the start of the switch-off, a large voltage increase can be seen, which is far above the voltage at the start of the switch-off, and even far above the charging voltage of the capacitor bank. This is due to the magnetic field of the circuit inductance, which should be prevented from breaking after the start of the disconnection by inducing a voltage or an induced current there (Lenz's law), which is in the same direction as the current in the circuit before the start of the disconnection. At the end of the disconnection, i.e. when the current in the circuit is equal to 0A, the voltage across the first switch (curve 4) is again the same as the voltage of the capacitor bank now isolated from the circuit. The isolation dam (isolationplaceteau) 7 begins at the end of the disconnection when the first switch is fully isolated. It can be seen that the voltage of the capacitor bank (curve 3) is equal to the voltage at the switch contacts (curve 4), while the isolation dam 7 is no longer decreasing. However, it can also be seen that the first switch becomes conductive again after a certain time, since the isolation dam 7 is not permanently held, but the voltage curve of the capacitor bank 3 after the isolation dam 7 drops again, i.e. the voltage curve of the capacitor bank 3 drops. This results in a further discharge of the capacitor bank. It is therefore clearly shown that the high current high voltage switch becomes conductive again after a certain time of circuit disconnection, as shown in fig. 5. The discharge current is about 10A, very small, which is no longer visible in the current curve 5, because the current scale here is very large.

Fig. 3 schematically shows a linearized time-dependent current profile 10 flowing through a first and a second switch, which are connected in series in the circuit according to fig. 1. The switching time point 8 of the first switch is at 0 seconds. Curve 10 represents the decreasing current distribution through the first and second switches. Curve 11 shows the energy input into the first switch after switching the first switch. The energy profile 11 extends according to the curve shown until the second switch is switched at 9. Without the second switch, the maximum energy consumption would end up at 16 points in the first switch, which would be much higher than the load capacity of switch 1 of 11000A (see dashed line). Curve 12 shows the energy reduction in the inductive load after switching the first switch.

If the second switch is switched at point in time 9, the current distribution through the first and second switch will decrease more quickly when the connection is broken, as shown by curve 13, since the load on the second switch is much lower. Likewise, the energy 15 in the inductive load also drops more quickly after switching the second switch. Curve 14 shows the energy curve over the second switch after switching the second switch, i.e. shows the energy absorbed by the second switch. The maximum energy consumption of the second switch is achieved at a very low level 17, so that the second switch will be able to open the circuit safely and permanently with a large margin, while the first switch will then become slightly conductive because its load exceeds its limit value of 11 kA.

Fig. 4a and 4b show a schematic view of the battery disconnector 100 before and after the disconnection of the disconnection zone 60. The battery disconnector 100 has a housing 20 through which the contact unit 30 passes. The contact unit 30 has a first connecting contact 40 on one side and a second connecting contact 50 on the other side, which are electrically connected to one another via a disconnection area 60 in the battery disconnector 100 in fig. 4 a. The disconnection zone 60 passes through a reaction chamber 70 enclosed by the housing 20. As shown in fig. 4a, the breaking zone 60 may have two predetermined breaking points 130, but may also have only one predetermined breaking point or more than two predetermined breaking points. The reaction chamber 70 is preferably filled with a fire extinguishing agent 90. Furthermore, a controllable drive 110 is provided in the reaction chamber 70, which is connected to a plunger 120. The controllable driver may be controlled by a control unit. The actuator 110 may be configured as, for example, a pyrotechnic actuator. If the driver 110 is actuated, the plunger 120 applies pressure to the disconnection area 60 of the contact unit 30. This results in the disconnection 60 being disconnected at the predetermined breaking point 130, as a result of which the first connection contact 40 and the second connection contact 50 are no longer connected. Fig. 4a shows the battery disconnector 100 in the conducting position, while fig. 4b shows the same battery disconnector 100 after switching in the non-conducting position, in which the disconnection area 6 is separated into separate parts 6a, 6b and 6 c. The pulse force can be set by the distance from the plunger 120 to the contact cell 30, which can be used to tear the contact cell apart in addition to the hydraulic pressure from the product pressure x depression area of the plunger 120 in the driver 110.

Fig. 5 shows a high current high voltage switch 100 comprising a housing 20, in which housing 20 a contact unit 30 is arranged. The housing 20 is designed such that it withstands the pressure generated within the housing 20, which pressure is generated, for example, when a high current high voltage switch 100 is activated by a pyrotechnic, without the risk of damage or even bursting. In the exemplary embodiment shown, the contact unit 30 is designed as a switching tube, which is pressed down in the compression region by the push-in reflector 101, so that it is designed as a tube in the disconnection region 60 and the compression region 190. In the embodiment shown, the contact unit 30 has a first connecting contact 40 with a larger diameter and a second connecting contact 50 with a smaller diameter. Following the first connecting contact 40 is a radially outwardly extending flange 150, which flange 150 is supported on an annular insulating element 220 (which is made of an insulating material, for example plastic), so that the contact unit 30 does not project axially outward from the housing 20. For this purpose, the insulating element 220 has an annular shoulder on which the flange 150 of the contact unit 30 rests. In addition, the insulating member 220 insulates the housing 20 from the contact unit 30. The contact unit 30 has a compression zone 190 that abuts the flange 150 on the axis of the contact unit 30. The wall thickness of the contact elements is selected and matched to the material in the compression zone 190 with a predetermined axial extent such that when the high-current high-voltage switch 100 is activated, the compression zone 190 is reduced by a predetermined distance in the axial direction due to the plastic deformation of the contact elements 30 in the compression zone 190, so that the separation distance existing after the disconnection process is greatly increased and results here from the addition of the compression distance and the length of the disconnection zone 60.

The flange 140 adjoins the compression region 190 in the axial direction of the contact unit 30, on which the thrust reflector 101 is provided in the exemplary embodiment shown. The push reflector 101 surrounds the contact unit 30 such that an insulation area of the push reflector 101 is engaged between the outer circumference of the flange 140 and the inner wall of the housing 20. If a pressure acts on the surface of the push reflector 101, a force is generated which compresses the compression zone 190 of the contact unit 30 via the flange 140. The force is selected such that during activation of the high-current high-voltage switch 100 the compression region 190 is compressed, wherein the push reflector 101 is moved from its starting position (state before activation of the high-current high-voltage switch 100) to the end position (after the end of the switching process).

The push reflector 101 or the flange 140 of the contact unit 30 is connected to the disconnection area 60. The second connecting contact 50 then rests against this side of the contact unit 30. The closure member 240 closes the housing 20.

In the exemplary embodiment shown, the push reflector 101 is pushed onto the contact unit 30 from the side of the connection contact 50 when the high-current high-voltage switch 100 is installed. The closure 240 is designed as an annular part, the outer diameter of which substantially corresponds to the inner diameter of the housing 20.

An actuator 110, preferably a pyrotechnical actuator, is arranged in the axial end of the contact unit 30 in the region of the second connection contact 50. The electrical connection lines 200 of the driver 110 can be led to the outside through the through-going portion of the annular closure 240.

The size of the disconnection zone 60 is designed such that it is at least partially disconnected by the generated gas pressure or the generated shock wave of the driver 110, so that this pressure or shock wave can also diffuse out of the combustion chamber 170 into the reaction chamber 70, which is designed as a surrounding annular space.

When the high-current high-voltage switch 100 is activated by means of the driver 110, a pressure or shock wave is generated on the side of the push reflector 101 facing away from the compression region 190, as a result of which the push reflector 101 is subjected to a corresponding axial force. The force is selected by appropriately dimensioning the pyrotechnic material such that the contact unit 30 is plastically deformed, broken or pressed in the compression zone 190 and then the push reflector 101 is moved in the direction of the first connection point 40. The pyrotechnic material is dimensioned in such a way that, in cooperation with the evaporation of the extinguishing agent 90, after the break-away zone 60 has been broken or pressurized, the movement of the propelling reflector 101 separates the two separate halves sufficiently far apart, even to the end position.

Immediately after the pyrotechnic material is activated, the break-away zone 60 is at least partially broken or compressed. If no fracture or compression occurs before the axial movement of the push-on reflector 101 starts over the entire circumference of the disconnection zone 60, the remaining part of the disconnection zone 60, which still causes the electrical contact, will completely fracture as a result of the axial movement of the push-on reflector 101, whereby the rapid heating of the now small remaining cross section of the conductor is increased by the current flowing through it.

In the embodiment shown in figure 5, the fire extinguishing agent 90 is located in the combustion chamber 170 and the reaction chamber 70, which promotes shock wave propagation when the pyrotechnic material is ignited or detonated, so that in this way less material has to be used and the walls of the breaking zone 60 can be kept sufficiently thick so that the assembly can also be used at high operating currents. The extinguishing agent 90 serves to attenuate or extinguish the arc between the separated ends of the interruption zone 60.

Furthermore, a channel can be provided in the high-current high-voltage switch 100, which channel is preferably arranged centrally in the axial direction below the thrust reflector 101, in particular extends centrally in the flange 140, and connects the combustion chamber 170 into the compression chamber 180 below the compression region 190. In the embodiment shown, the contact unit 30 is therefore further designed as a continuous switching tube. In this embodiment, the combustion chamber 170, the channels, the reaction chamber 70, and the compression chamber 180 may all be filled with the fire extinguishing agent 90. The channel ensures that upon activation of the high current high voltage switch 100 and movement of the push reflector 101 from the starting position to the ending position, the increased volume in the area of the combustion chamber 170 and the reaction chamber 70 is also filled with extinguishing agent 90. Due to the movement of the push reflector 101 from the starting position to the end position, the extinguishing medium 90 is compressed in the compression chamber 180 and is sprayed through the passage in the direction of the area of the combustion chamber 170 and here directly onto the shut-off region 60. In this way, arcs between the separate portions of the breaking zone 60 may be additionally attenuated or extinguished.

Furthermore, a sealing element 230 is preferably provided in the high current high voltage switch 100 for sealing the various chambers 70, 170 and 180 from escaping the fire suppressant 90 and for sealing the various components from each other.

List of reference numerals:

1 circuit

S1 first switch

S2 second switch

2 control unit

L-inductive load

W_LLoad resistance

3 voltage curve of capacitor bank

4 voltage profile in the first switch

Current curve of the entire circuit

6 point in time of opening the first switch

7 isolation dam

8 switching time point of the first switch

9 switching time point of the second switch

10 current profile through the first and second switches

11 after switching the first switch (the second switch is not switched), the energy input to the first switch

12 energy reduction of the magnetic field of the inductive load after switching the first switch

13 current profile through the first and second switches when the second switch is switched

14 energy input to the second switch after switching the first switch

15 energy reduction of the magnetic field of the inductive load after switching the second switch

16 maximum energy consumption of the first switch (second switch not switched)

17 maximum power consumption of the second switch

100 switch (high current high voltage switch/battery disconnector)

20 casing

30 contact unit

40 first contact point

50 second connection contact

60 break-off zone

60a separation part of the breaking zone

60b separation part of the breaking zone

60c separation of the cleavage zone

70 reaction chamber

90 fire extinguishing agent

101 push reflector

110 driver

120 plunger

130 breaking point

140 flange

150 flange

170 combustion chamber

180 compression chamber

190 compression zone

200 electric connecting wire

220 insulating element

230 sealing element

240 closure

250 closure element for compression chamber