DC voltage switch

Abstract

The present invention relates to a DC voltage switch for coupling a DC voltage branch to a DC voltage bus. In the forward direction, current flows from the positive conductor of the DC voltage bus via the DC voltage switch to the positive conductor of the DC voltage branch. In the reverse direction, current flows from the positive conductor of the DC voltage branch via the DC voltage switch to the positive conductor of the DC voltage bus, and from the negative conductor of the DC voltage bus via the DC voltage switch to the negative conductor of the DC voltage branch. The DC voltage switch has: a semiconductor-based electronically controllable switching device, a voltage sensor on the DC voltage bus side provided before the switching device for determining the voltage level on the DC voltage bus side, a voltage sensor on the DC voltage branch side provided after the switching device for determining the voltage level on the DC voltage branch side, a current sensor for determining the current level and the current direction, and a control device connected to the switching device, the voltage sensors, and the current sensor, wherein the control device is designed to determine the direction and the current level of the current, interrupt the current flow through the switching device when a first threshold value of the current level is exceeded, and in the case of a reverse direction when the first threshold value of the current level is exceeded: after interrupting the current flow, compare the voltage level on the DC voltage bus side with the voltage level on the DC voltage branch side, and switch the switching device to the conducting state when the voltage difference is less than a certain voltage difference value.

Description

Technical Field

[0001] The present invention relates to a DC voltage switch and related methods for coupling a DC voltage device or a DC voltage branch having positive and negative conductors to a DC voltage bus. Background Art

[0002] DC voltage refers to a voltage of up to 1500 volts. DC voltage up to this level is also referred to as low voltage. More specifically, DC voltage particularly refers to a voltage greater than the level of low voltage having a DC voltage of 120 volts. DC voltage particularly refers to a voltage of 400 - 800 volts.

[0003] A DC voltage circuit or a DC circuit refers to a circuit for a current from 2 to 1000 amperes, particularly the nominal current or the maximum current; more specifically, a circuit for a current from 2 amperes to 400 amperes or 200 amperes.

[0004] A DC voltage bus refers to at least a two - wire system having a positive conductor and a negative conductor that provides DC voltage by at least one energy source. (DC voltage) devices, such as DC voltage consuming devices, loads, inverters, combined energy sinks or energy sources, simple (additional) energy sources, etc., are correspondingly connected to the DC voltage bus through DC voltage branches. Multiple DC voltage devices can also be connected to one DC voltage branch.

[0005] DC voltage devices particularly refer to devices having a power of 1 kW to 500 kW.

[0006] At the same time, DC voltage circuits, also known as DC voltage networks or low - voltage DC networks, are increasingly developed and constructed, which usually have a DC voltage bus with DC voltage branches.

[0007] DC voltage branches, also known as device branches, are usually protected by DC voltage switches (DC switches). These DC voltage switches have switching devices.

[0008] Figure 1 A schematic diagram of a DC voltage circuit, a DC voltage network, a low - voltage DC network, or a DC network is shown, which has a DC voltage bus DCB and multiple DC voltage branches DCA1, DCA2, DCA3, and the DC voltage branches DCA1, DCA2, DCA3 have DC voltage switches S1, S2, S3.

[0009] Figure 1In principle, a DC voltage source EQ connected to a DC voltage bus DCB via a feed switch S4 is shown. A first DC voltage branch DCA1 having at least one first DC voltage device G1 is connected to the DC voltage bus DCB via a first DC voltage switch S1; in a similar manner, a second DC voltage branch DCA2 having at least one second DC voltage device G2 is connected to the DC voltage bus DCB via a second DC voltage switch S2, and a third DC voltage branch DCA3 having at least one third DC voltage device G3 is connected to the DC voltage bus DCB via a third DC voltage switch S3.

[0010] Additional DC voltage switches, DC voltage branches, and DC voltage devices can be provided. The DC voltage switch can be an outgoing switch (Abgangsschalter). The DC voltage device typically has a capacitor that can store a non-trivial amount of energy.

[0011] If a fault occurs in the DC voltage circuit according to Figure 1 , for example, a short circuit occurs at a fault location F1 between the first DC voltage switch S1 and the first (DC voltage) device G1 in the first DC voltage branch DCA1, then power is fed from the energy source EQ, and also from the surrounding DC voltage branches, in this example the second and third DC voltage branches DCA2, DCA3 or the energy sources or capacitors located therein, to the short circuit there. This results in a large current being generated in the relevant switching device, in this example in the second or third DC voltage switches S2, S3 that are triggered / triggerable by disconnection (Abschaltung).

[0012] The second and third devices G2, G3 or their capacitors may supply a large (fault) current. If, for example, the second device G2 has a small nominal current, then the second DC voltage switch S2 is correspondingly small, and the second DC voltage switch S2 may interrupt the current flow even when the fault occurs in another branch.

[0013] In principle, the surrounding DC voltage switches (S2, S3) should block the current flowing from the corresponding DC voltage branch or the electrical device branch to the short circuit F1 as little as possible, in order to reliably trigger the DC voltage switch, in this example the first DC voltage switch S1.

[0014] Furthermore, it is important here not to trigger the surrounding DC voltage switches (S2, S3), so as to effect a so-called selective disconnection of the fault (via S1).

[0015] As shown above, this is not always ensured. Especially when the surrounding DC voltage switch has a switching device, and the switching device has semiconductor switching elements. The semiconductor switching elements usually have a saturation current that is less than the short-circuit current in the event of a fault, and thus act as a current limiter. In addition, the semiconductor switching elements can only carry this saturation current for a short time, usually in the range of single-digit microseconds. Therefore, the DC voltage switch must be disconnected (self-protected), that is, the current flow is interrupted, regardless of the required selectivity, to protect the semiconductor switching elements.

[0016] So far, this problem has been solved in the following way, that is, the DC voltage switch either has an electromechanical switching device or is designed to be oversized, which is expensive or uneconomical. Summary of the Invention

[0017] The technical problem to be solved by the present invention is to improve the switching characteristics of the DC voltage switch to achieve selectivity, especially for DC voltage switches with semiconductor-based switching devices, and to provide a solution to the above-mentioned problem.

[0018] The above technical problem is solved by a DC voltage switch having the features of claim 1 or a method having the features of claim 16.

[0019] According to the present invention, a DC voltage switch is proposed for coupling a DC voltage branch provided for at least one DC voltage device to a DC voltage bus using a positive conductor and a negative conductor, wherein the forward direction of the current is defined by the following current flow, the current flowing from the positive conductor of the DC voltage bus DCB through the DC voltage switch to the positive conductor of the DC voltage branch, and from the negative conductor of the DC voltage branch through the DC voltage switch to the negative conductor of the DC voltage bus.

[0020] Therefore, the reverse direction of the current is defined as flowing from the positive conductor of the DC voltage branch through the DC voltage switch to the positive conductor of the DC voltage bus, and from the negative conductor of the DC voltage bus through the DC voltage switch to the negative conductor of the DC voltage branch.

[0021] The DC voltage switch has:

[0022] - A semiconductor-based electronically controllable switching device,

[0023] - A voltage sensor on the DC voltage bus side provided before the switching device for determining the voltage level on the DC voltage bus side,

[0024] - A voltage sensor on the DC voltage branch side provided after the switching device for determining the voltage level on the DC voltage branch side,

[0025] - A current sensor for determining the current level and current direction,

[0026] - A control device connected to the switching device, voltage sensor and current sensor.

[0027] The control device is designed to,

[0028] - Determine the direction and current level of the current, in particular periodically determine the direction and current level,

[0029] - When exceeding the first threshold value (current threshold) of the current level, interrupt the current flow through the switching device,

[0030] - In the case where there is a reverse direction when exceeding the first threshold value of the current level:

[0031] - After interrupting the current flow, compare the voltage level on the DC voltage bus side with the voltage level on the DC voltage branch side. If the voltage difference is less than a certain voltage difference value, switch the switching device to the conducting state.

[0032] This has the following advantages: when the DC voltage switch is accidentally disconnected due to excessive current flow, when the current (current level) causing the disconnection does not flow towards the DC voltage device but from the DC voltage device towards the DC voltage bus, reconnection is performed. That is to say, there is no fault in the DC voltage branch of the DC voltage switch, but there is a fault on the DC voltage bus or on the side of another DC voltage branch. In addition, when the voltage level on the DC voltage bus again corresponds to a value approximately corresponding to the voltage level in the DC voltage branch. In this case, it can be assumed that the faulty branch has been disconnected and the voltage on the DC voltage bus has been normalized, so normal power supply continues to the non-faulty DC voltage branch that has been accidentally disconnected.

[0033] Advantageous designs of the present invention are given in the dependent claims.

[0034] In an advantageous design of the present invention, the switching device has at least one, in particular two, semiconductor switching elements that guide the current flow on the positive or negative conductor side.

[0035] This has the following particular advantages: a particularly simple solution is given for the switching device.

[0036] In an advantageous design of the present invention, the semiconductor switching element is a bipolar transistor with an insulated gate electrode, a metal-oxide semiconductor field effect transistor or a gallium nitride transistor.

[0037] This has the following particular advantages: a simple solution is given for the semiconductor switching element of the switching module.

[0038] In an advantageous design of the present invention, the semiconductor switching element is connected in parallel with a diode, and the conduction direction of the diode is particularly opposite to that of the semiconductor switching element.

[0039] This has the following particular advantage, namely, for unidirectional semiconductor switching elements, especially when two unidirectional semiconductor switching elements are connected in series, a simple solution is provided.

[0040] In an advantageous design of the present invention, the diode has a low conduction voltage, and the diode is particularly a network diode or a Schottky diode.

[0041] This has the following particular advantage, namely, a particularly low voltage drop is presented in the reverse direction, whereby on the one hand, a low power loss is presented, and on the other hand, a maximum current is given in the reverse direction to improve selectivity.

[0042] In an advantageous design of the present invention, the DC voltage switch is arranged in a housing.

[0043] This has the following particular advantage, namely, a compact DC voltage switch is provided in one housing.

[0044] In an advantageous design of the present invention, the housing has a positive conductor input connector, a negative conductor input connector, a positive conductor output connector, and a negative conductor output connector. The input connectors can be connected to a DC voltage bus. The output connectors can be connected to a DC voltage branch.

[0045] The switching device connects the positive conductor input connector to the positive conductor output connector, or the switching device connects the negative conductor input connector to the negative conductor output connector.

[0046] In a variant, switching devices can be provided in the positive and negative conductors.

[0047] This has the following particular advantage, namely, a simple solution is provided for a compact DC voltage switch.

[0048] In an advantageous design of the present invention, the connectors without switching devices are connected to each other by electric wires.

[0049] This has the following particular advantage, namely, a simple solution is provided for the DC voltage switch, especially a solution for single-pole switching.

[0050] In an advantageous design of the present invention, the voltage difference is 10 volts.

[0051] This has the particular advantage that it minimizes an excessive compensation current between the DC voltage branch and the DC voltage bus, or the voltage difference exceeds a large degree.

[0052] In an advantageous embodiment of the invention, the current sensor is a Hall effect-based sensor.

[0053] This has the particular advantage that it provides a simple solution for determining the level and direction of the current.

[0054] In an advantageous embodiment of the invention, the control device is also designed to interrupt the current flow through the switching device when the current rise exceeds the current rise threshold.

[0055] This has the particular advantage that it provides another protection criterion for the DC voltage switch for targeted triggering or self-protection.

[0056] In an advantageous embodiment of the invention, a power supply, an energy storage, or a connector for external energy supply is provided for the control device.

[0057] This has the particular advantage that it provides, in particular, the energy supply after triggering the DC voltage switch.

[0058] In an advantageous embodiment of the invention, the control device has a microprocessor.

[0059] This has the particular advantage that it enables the DC voltage switch to be controlled in a particularly comfortable or variable manner.

[0060] All embodiments, not only in the form of dependencies referring to claim 1 or 16, but also referring only to individual features or combinations of features of the claims, improve the DC voltage switch, thereby improving the selectivity in the DC voltage network. Thus, in particular, devices with different power levels can be operated on a common DC voltage bus. Description of the Drawings

[0061] The described features, characteristics, and advantages of the invention and the ways of achieving them will become clearer and easier to understand in connection with the description of the embodiments described in detail below in conjunction with the drawings.

[0062] In the associated drawings:

[0063] Figure 1 shows a schematic diagram of a DC voltage circuit having a DC voltage bus and a plurality of DC voltage branches, the DC voltage branches having DC voltage switches,

[0064] Figure 2Shows a diagram of a DC voltage switch together with a DC voltage bus, a DC voltage branch, and a DC voltage device according to the present invention,

[0065] Figure 3 Shows an example of a switching device having a semiconductor switching element. Detailed Description

[0066] Figure 1 Shows a schematic diagram of a DC voltage circuit according to the prior art as described at the beginning, the DC voltage circuit having a DC voltage bus and a plurality of DC voltage branches, the DC voltage branches having DC voltage switches.

[0067] Figure 2 Shows a DC voltage switch Sx having a housing GEH, which can be used, for example, as the first, second, or third switch S1, S2, S3 according to Figure 1 . The housing GEH has a positive conductor input connection PE, a negative conductor input connection ME, a positive conductor output connection PA, and a negative conductor output connection MA.

[0068] The input connections PE, ME are connected to the DC voltage bus DCB, which has a positive conductor DCP(+) and a negative conductor DCN(-).

[0069] The output connections PA, MA are connected to the DC voltage branch DCA, which in turn is connected to at least one DC voltage device Gx, for example the first, second, or third device G1, G2, G3 according to Figure 1 .

[0070] The DC voltage switch Sx has a switching device SCH.

[0071] Inside the housing, the switching device SCH either connects the positive conductor input connection PE to the positive conductor output connection PA, as shown, or connects the negative conductor input connection ME to the negative conductor output connection MA.

[0072] Alternatively, two switching devices, namely a first and a second switching device, can also be provided. Among them, the first switching device is arranged for the positive conductor connection, and the second switching device is arranged for the negative conductor connection.

[0073] According to Figure 2 , the connections without the switching device SCH are connected to each other by electrical wires. In this example, the negative conductor input connection ME is connected to the negative conductor output connection MA by an electrical wire.

[0074] Before the switching device SCH, i.e., on the DC voltage bus DCB side, a voltage sensor U1 of the DC voltage bus side is provided between the positive and negative conductors for determining the voltage level on the DC voltage bus side.

[0075] After the switching device SCH, i.e., on the DCA side of the DC voltage branch, a voltage sensor U2 on the DC voltage branch side is provided between the positive and negative conductors for determining the voltage level on the DC voltage branch side.

[0076] In the positive conductor or the negative conductor, before or after the switching device SCH, a current sensor I is provided for determining the current level and the current direction. The current sensor can be a Hall effect-based sensor.

[0077] The switching device SCH is a semiconductor-based electronically controllable switching device SCH. It can have at least one semiconductor switching element that guides (depending on the position, on the positive conductor or negative conductor side) the current flow. In particular, two semiconductor switching elements that guide (depending on the position, on the positive conductor or negative conductor side) the current flow can be provided. The semiconductor switching element can be a bipolar transistor with an insulated gate electrode, a metal-oxide-semiconductor field-effect transistor, or a gallium nitride transistor.

[0078] The semiconductor switching element can be connected in parallel with a diode, and the conduction direction of the diode is especially opposite to that of the semiconductor switching element. The diode can have a low conduction voltage and can especially be a network diode or a Schottky diode.

[0079] A control device SE is provided, which is connected to the switching device SCH, the voltage sensors U1, U2, and the current sensor I. The control device SE can have a microprocessor.

[0080] The control device can be supplied with energy by a power supply (not shown). The power supply can be connected to the input interface on the DC voltage bus side and / or the output interface on the DC voltage branch side.

[0081] Alternatively or additionally, an energy storage device, such as a supercapacitor, a storage battery, or a battery, can be provided for supplying energy to the control device SE in case of a short circuit / fault or triggering on the DC voltage branches DCA1, DCA2, DCA3 or the DC voltage bus DCB. Alternatively, a connection for external energy supply to the control device and, if necessary, other devices of the DC voltage switch Sx can be provided.

[0082] The control device is designed to

[0083] -(especially periodically) determine the direction and the level of the current,

[0084] -interrupt the current flow through the switching device SCH when a first threshold of the current level, i.e., the current threshold, is exceeded,

[0085] - In the case where there is a current in the reverse direction shortly before or during the first threshold of the over - current level:

[0086] - After interrupting the current flow, the voltage level on the DC voltage bus side is (periodically) compared with the voltage level on the DC voltage branch side, and if the voltage difference is less than the voltage difference value, the switching device is switched to the conducting state. For example, this voltage difference value can be 10 volts. That is, if the voltage difference between the DC voltage bus DCB and the DC voltage branch DCA is less than 10 volts, the control device SE reconnects the switching device SCH, and for current flow, the switching device SCH becomes conducting.

[0087] Additionally, the control device SE can also be designed to interrupt the current flow through the switching device when the rise of the current exceeds the current - rise threshold. After this type of interruption, the present invention can also be used, and in the case where there is a current flow in the reverse direction at the time of triggering / current interruption, the voltage can be compared and switched on if necessary.

[0088] Furthermore, in the positive conductor or the negative conductor, before or after the switching device SCH, a separating contact or a disconnecting switch can be provided in one or both conductors (positive conductor, negative conductor) for the (galvanischen) separation of the current of the DC voltage device or the DC voltage switch. The separating contact can be switched by the control device SE.

[0089] Figure 3 An example of a switching device SCH with semiconductor switching elements is shown. The switching device SCH has a series circuit of a first and a second semiconductor switching element Q1, Q2. For example, the controllable first semiconductor switching element Q1 conducts for the first current direction, while the controllable second semiconductor switching element Q2 conducts for the opposite current direction.

[0090] The first semiconductor switching element Q1 is connected in parallel with a first diode D1, and the first diode D1 conducts in the current direction opposite to that of the first semiconductor switching element Q1, and the second semiconductor switching element Q2 is connected in parallel with a second diode D2, and the second diode D2 conducts in the first current direction of the first semiconductor switching element Q1.

[0091] The switching device SCH is implemented with a bipolar connection (for the positive and negative conductors). In this example, the first and second semiconductor switching elements Q1, Q2 are located in one conductor, in this example, in the positive conductor; the negative conductor is continuous and has no semiconductor switching element.

[0092] Alternatively, the semiconductor switching elements can also be arranged in the negative conductor, or both conductors can have semiconductor switching elements.

[0093] After the series connection of two semiconductor switching elements Q1, Q2, there is a disconnecting contact on the device side or the DC voltage branch side. For the positive conductor, a first disconnecting contact TK1 is provided, and for the negative conductor, a second disconnecting contact TK2 is provided, which are generally referred to as disconnecting contacts for current isolation of the DC voltage branch or the device.

[0094] The switching device SCH can also be constructed in other ways, for example, by a parallel circuit of two semiconductor switching elements Q1, Q2. Each of the semiconductor switching elements Q1, Q2 can be connected in series with a diode, and these series circuits are connected in parallel. Other variants are also conceivable.

[0095] Next, the present invention will be shown again in another way of saying.

[0096] In a DC voltage network with distributed capacitance in the load outgoing line and the feed circuit path, in the future, the protection of machines and operating equipment can be achieved by a power electronic DC voltage switch (switch). Here, the selectivity of the switch is desired. Now, the selectivity requirement is to only (continuously) disconnect the faulty branch, while all other branches remain active.

[0097] Semiconductor-based switching elements, such as Si-IGBT or SiC MOSFET, can achieve a saturation current less than the short-circuit current in case of a fault. Since these switching elements can only carry such a saturation current for a very short time (within the μs range), these switches must all be disconnected for self-protection, regardless of the selectivity required in such a DC voltage system.

[0098] According to the present invention, two possibilities for achieving selectivity are proposed:

[0099] A: Evaluate the voltage and short-circuit current before disconnecting the switch,

[0100] B: Evaluate the voltage after disconnecting the switch and, if necessary, perform a rapid reconnection.

[0101] In a DC voltage network with distributed capacitance and drive line inductance, bidirectional power electronic switches should be used to protect the outgoing line. For self-protection, these switches can have current and voltage measurements (not only on the emitter-collector but also between the poles (Polen)). Therefore, the following parameters can be detected, namely current, current rise rate, voltage, and voltage change rate.

[0102] Depending on the current direction, a DC voltage switch, such as the outgoing line switch S1, can determine whether a fault has occurred in its DC voltage branch or outgoing line, and if the fault itself is reliably identified based on the current rise and voltage drop, whether it must remain open.

[0103] If the switch must be opened for self - protection, then the above - mentioned parameters can be detected and buffered for evaluation by a microcontroller or controller in the switch. Here, for the operation of the switch, there is advantageously a continuously available control voltage.

[0104] For the second and third DC voltage switches S2, S3 in adjacent branches or outgoing lines with similar or smaller power, in the event of a fault, the current flows in the reverse direction, towards the DC voltage bus or DC distribution device, and the time point of re - connection can additionally be determined by the voltage drop (discharge of the capacitor in the outgoing line) and the depth of the repeated voltage due to other power - feeding paths and line inductance, and this re - connection will be in the millisecond range / ms range.

[0105] U s (t)=R L ·I s (t)+L L (dl s (t) / dt)-∫I s (t) / Cdt + UFehler

[0106] If the switch must be opened for self - protection, then S2 and S3 can decide to re - connect as soon as possible based on the current direction. In this case, S4 will identify the recovery of the DC voltage, and if it has been opened, it can also re - connect very quickly. S1 remains open due to the short - circuit, thus due to the absence of voltage on the outgoing line.

[0107] The present invention has the following advantages: compared with protection using electromechanical power switches, when, according to the criteria of the matching system, the power electronic switch cannot be opened or re - connected, and before the capacitor is completely discharged and the system must be restarted, power supply to the non - faulty outgoing lines cannot be continued, selectivity in the DC voltage network with capacitive buffering can be ensured.

[0108] In particular, for these criteria, not only the flowing current is considered, but also the voltage and its corresponding changes. In this regard, the rapid opening and re - connection of the power electronic switch are crucial.

[0109] It is advantageous to obtain improved selectivity without over - sizing the semiconductor switch.

[0110] Although the present invention has been described in more detail by way of examples in terms of details, the present invention is not limited to the disclosed examples, and those skilled in the art can derive other variants therefrom without departing from the scope of protection of the present invention.

Claims

1. A DC voltage switch (Sx) for coupling a DC voltage branch (DCA, DCA1, DCA2, DCA3) provided for at least one DC voltage device (Gx) to a DC voltage bus (DCB) using a positive conductor and a negative conductor, the DC voltage switch (Sx) being arranged in a housing (GEH), wherein, In the forward direction, current flows from the positive conductor (DCP) of the DC voltage bus (DCB) via the DC voltage switch (Sx) to the positive conductor of the DC voltage branch (DCA), and from the negative conductor of the DC voltage branch (DCA) via the DC voltage switch (Sx) to the negative conductor (DCN) of the DC voltage bus (DCB). And in the reverse direction, current flows from the positive conductor of the DC voltage branch (DCA) via the DC voltage switch (Sx) to the positive conductor (DCP) of the DC voltage bus (DCB), and from the negative conductor (DCN) of the DC voltage bus (DCB) via the DC voltage switch (Sx) to the negative conductor of the DC voltage branch (DCA). The DC voltage switch (Sx) has: A semiconductor-based electronically controllable switching device (SCH). A DC voltage bus-side voltage sensor (U1) provided in front of the semiconductor-based electronically controllable switching device (SCH) for determining the voltage level of the DC voltage bus side (DCB). A DC voltage branch-side voltage sensor (U2) provided behind the semiconductor-based electronically controllable switching device (SCH) for determining the voltage level of the DC voltage branch side (DCA). A current sensor (I) for determining the current level and the current direction, and A control device (SE) connected to the semiconductor-based electronically controllable switching device (SCH), the DC voltage bus-side voltage sensor (U1), the DC voltage branch-side voltage sensor (U2), and the current sensor (I), wherein the control device (SE) is designed to - Determine the direction and the current level of the current. - Interrupt the current flow through the semiconductor-based electronically controllable switching device (SCH) when a first threshold value of the current level is exceeded. - In the case of a reverse direction when the first threshold value of the current level is exceeded: - After interrupting the current flow, compare the voltage level of the DC voltage bus side (DCB) with the voltage level of the DC voltage branch side (DCA), and switch the semiconductor-based electronically controllable switching device (SCH) to the conducting state when it is determined by the comparison that the voltage difference is less than a certain voltage difference value.

2. The DC voltage switch (Sx) according to claim 1, characterized in that, The semiconductor-based electronically controllable switching device (SCH) has at least one semiconductor switching element (Q1, Q2) that conducts current flow between the positive conductor of the DC voltage bus and the DC voltage branch or between the negative conductor of the DC voltage bus and the DC voltage branch.

3. The DC voltage switch (Sx) according to claim 2, characterized in that, The semiconductor switching elements (Q1, Q2) are bipolar transistors, metal-oxide-semiconductor field-effect transistors, or gallium nitride transistors having insulated gate electrodes.

4. The DC voltage switch (Sx) according to claim 2, characterized in that, The semiconductor switching elements (Q1, Q2) are connected in parallel with diodes (D1, D2), wherein the conduction direction of the diodes is opposite to the conduction direction of the semiconductor switching elements (Q1, Q2).

5. The DC voltage switch (Sx) according to claim 4, characterized in that, The diodes (D1, D2) have a low conduction voltage, and the diodes are network diodes or Schottky diodes.

6. The DC voltage switch (Sx) according to claim 1, characterized in that, The housing (GEH) has a positive conductor input connection (PE), a negative conductor input connection (ME), a positive conductor output connection (PA), and a negative conductor output connection (MA); The input connections (PE, ME) can be connected to a DC voltage bus (DCB); The output connections (PA, MA) can be connected to a DC voltage branch (DCA); A semiconductor-based electronically controllable switching device (SCH) is arranged between the positive conductor input connection (PE) and the positive conductor output connection (PA), and / or A semiconductor-based electronically controllable switching device (SCH) is arranged between the negative conductor input connection (ME) and the negative conductor output connection (MA).

7. The DC voltage switch (Sx) according to claim 6, characterized in that, The connections without a semiconductor-based electronically controllable switching device (SCH) are interconnected by electrical conductors.

8. The DC voltage switch (Sx) according to any one of claims 1 to 7, characterized in that, The voltage difference is 10 volts.

9. The DC voltage switch (Sx) according to any one of claims 1 to 7, characterized in that, The DC voltage switch (Sx) is an outgoing line switch, or the DC voltage switch (Sx) is used in an outgoing line switch.

10. The DC voltage switch (Sx) according to any one of claims 1 to 7, characterized in that, The current sensor (I) is a Hall effect-based sensor.

11. The DC voltage switch (Sx) according to any one of claims 1 to 7, characterized in that, The control device (SE) is also designed to interrupt the current flow through the semiconductor-based electronically controllable switching device when the current rise exceeds a current rise threshold.

12. The DC voltage switch (Sx) according to any one of claims 1 to 7, characterized in that, A power supply, an energy storage device, or a connection for external energy supply is provided for supplying energy to the control device (SE).

13. The DC voltage switch (Sx) according to any one of claims 1 to 7, characterized in that, The control device (SE) has a microprocessor.

14. A DC voltage branch (DCA) having a DC voltage switch (Sx) according to any one of claims 1 to 13, wherein, The DC voltage switch (Sx) is connected to the DC voltage bus (DCB) on the one hand and to an electrical device on the other hand.

15. A method for coupling a DC voltage branch (DCA, DCA1, DCA2, DCA3) provided for at least one DC voltage device (Gx) to a DC voltage bus (DCB) using a positive conductor and a negative conductor; wherein, In the forward direction, the current flows from the positive conductor (DCP) of the DC voltage bus (DCB) via the DC voltage switch (Sx) having a switching device (SCH) to the positive conductor of the DC voltage branch (DCA), and from the negative conductor of the DC voltage branch (DCA) via the DC voltage switch (Sx) to the negative conductor (DCN) of the DC voltage bus (DCB), and in the reverse direction, the current flows from the positive conductor of the DC voltage branch (DCA) via the DC voltage switch (Sx) to the positive conductor (DCP) of the DC voltage bus (DCB), and from the negative conductor (DCN) of the DC voltage bus (DCB) via the DC voltage switch (Sx) to the negative conductor of the DC voltage branch (DCA), the DC voltage switch (Sx) is arranged in the housing (GEH); the method includes: Determining the voltage level on the DC voltage bus side (DCB), Determining the voltage level on the DC voltage branch side (DCA), Determining the current level and the current direction, Interrupting the current flow through the switching device when the first threshold of the current level is exceeded, In the case of a reverse direction when the first threshold of the current level is exceeded: after interrupting the current flow, comparing the voltage level on the DC voltage bus side (DCB) with the voltage level on the DC voltage branch side (DCA), and switching the switching device (SCH) to the conducting state when the voltage difference is less than a certain voltage difference.

16. A DC voltage switch (Sx) for coupling a DC voltage branch (DCA, DCA1, DCA2, DCA3) provided for at least one DC voltage device (Gx) to a DC voltage bus (DCB) by means of a positive conductor and a negative conductor, wherein, In the forward direction, current flows from the positive conductor (DCP) of the DC voltage bus (DCB) via the DC voltage switch (Sx) to the positive conductor of the DC voltage branch (DCA), and from the negative conductor of the DC voltage branch (DCA) via the DC voltage switch (Sx) to the negative conductor (DCN) of the DC voltage bus (DCB). And in the reverse direction, current flows from the positive conductor of the DC voltage branch (DCA) via the DC voltage switch (Sx) to the positive conductor (DCP) of the DC voltage bus (DCB), and from the negative conductor (DCN) of the DC voltage bus (DCB) via the DC voltage switch (Sx) to the negative conductor of the DC voltage branch (DCA). The DC voltage switch (Sx) has: A semiconductor-based electronically controllable switching device (SCH). A DC voltage bus-side voltage sensor (U1) provided in front of the semiconductor-based electronically controllable switching device (SCH) for determining the voltage level of the DC voltage bus side (DCB). A DC voltage branch-side voltage sensor (U2) provided behind the semiconductor-based electronically controllable switching device (SCH) for determining the voltage level of the DC voltage branch side (DCA). A current sensor (I) for determining the current level and current direction, the current sensor being a Hall effect-based sensor, and A control device (SE) connected to the semiconductor-based electronically controllable switching device (SCH), the DC voltage bus-side voltage sensor (U1), the DC voltage branch-side voltage sensor (U2), and the current sensor (I), wherein the control device (SE) is designed to - Determine the direction and current level of the current. - Interrupt the current flow via the semiconductor-based electronically controllable switching device (SCH) when a first threshold value of the current level is exceeded. - In the case of a reverse direction when the first threshold value of the current level is exceeded: - After interrupting the current flow, compare the voltage level of the DC voltage bus side (DCB) with the voltage level of the DC voltage branch side (DCA), and switch the semiconductor-based electronically controllable switching device (SCH) to the conducting state when it is determined by the comparison that the voltage difference is less than a certain voltage difference value.

17. The DC voltage switch (Sx) according to claim 16, characterized in that, The semiconductor-based electronically controllable switching device (SCH) has at least one semiconductor switching element (Q1, Q2) for guiding the current flow between the positive conductor of the DC voltage bus and the DC voltage branch or between the negative conductor of the DC voltage bus and the DC voltage branch.

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