ELECTRONIC CIRCUIT SWITCH, CIRCUIT ARRAY WITH AN ELECTRONIC CIRCUIT SWITCH AND METHOD FOR PREVENTING A STRANGE ARC MEANS OF AN ELECTRONIC CIRCUIT SWITCH

Description

[0001] The invention relates to a device according to the preamble of claim 1.

[0002] From DE 10 2011 120 466 A1, an electronic circuit breaker for protecting electrical loads arranged in an electrical circuit in the event of a defect, for example a short circuit, is known. EP3916940A1 discloses a known electronic circuit breaker according to the preamble of claim 1.

[0003] During normal operation of an electrical circuit, a so-called arc fault can occur due to faulty insulation or a break in an electrical conductor between a power source and an electrical load, or due to an intermittent connection between the power source and the load. The power source can be a power supply unit, a battery, a busbar output, or a similar component for electrical power supply. An arc fault can not only damage or destroy components of the electrical circuit, but can also cause serious injuries or fires. Therefore, there is a need for electronic circuit breakers to reduce the risk of arc faults.

[0004] The invention is based on the objective of further developing a generic electronic circuit breaker in such a way that it can prevent the formation of an arc fault in the circuit during intended operation of a circuit.

[0005] This problem is solved by an electronic circuit breaker having the features of claim 1.

[0006] According to the invention, the electronic circuit breaker comprises an input and an output. A current path for a load current runs between the input and the output. An actuator is arranged in the current path, which has a closed state and an open state. In the open state, the current path is open and blocks the load current. In the closed state, the current path is closed and allows the load current to pass. The actuator can be designed as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), an IGBT (Insulated Gate Bipolar Transistor), an electromagnetically, electrothermally, or electromechanically actuated mechanical switch, or a hybrid combination of the aforementioned and further examples.

[0007] The electronic circuit breaker also includes a control unit. The control unit is designed to switch the actuator between the open and closed states. During normal operation of the electronic circuit breaker, an input voltage Uin is present at the input.

[0008] According to the invention, the electronic circuit breaker comprises an energy storage device that is electrically connected to the current path. The electronic circuit breaker is designed such that, when the electronic circuit breaker is installed in a circuit for conducting the load current through the current path, a charge signal is transmitted to the control unit. Changes in this signal correlate with changes in the charge of the energy storage device. When the charge signal detects a discharge of the energy storage device while the actuator is closed, the control unit measures a discharge time during which the energy storage device is continuously discharged. If a limit value for the discharge time is exceeded, the control unit switches the actuator to the open state, thereby preventing the formation of an arc fault in the circuit. The control unit receives the charge signal.The charge signal is a measurable and measured value of a physical quantity that correlates with the state of charge of the energy storage device and enables the control unit to determine whether the energy storage device is being charged or discharged during the intended operation of the circuit.

[0009] An arc fault occurring in the circuit, particularly a series arc fault (SSLB) in an electrical line connected to the input of the electronic circuit breaker, causes a drop in the input voltage Uin of the electronic circuit breaker. The energy storage device counteracts this drop in input voltage Uin by discharging. If the detected discharge lasts longer than the discharge time limit, the control unit disconnects the load from a voltage source in the circuit by switching the actuator to the open state, i.e., by interrupting the current path. This prevents or immediately extinguishes the arc fault, particularly the series arc fault.

[0010] In other words, the electronic circuit breaker distinguishes between a series arc fault and operational fluctuations in the circuit based on the duration of the discharge. While operational fluctuations in the circuit typically result in very short discharges of the energy storage device, a series arc fault causes a relatively long discharge of the energy storage device.

[0011] The electronic circuit breaker can be designed as a single, integrated component comprising a housing in which all its components are arranged. Alternatively, components of the electronic circuit breaker can be distributed throughout the circuit and / or integrated into circuit components. For example, the energy storage device and control unit, on the one hand, and the actuator, on the other, can be located at opposite ends of the electrical conductor. It is also possible for the electronic circuit breaker to be integrated into the circuit's load.

[0012] The electronic circuit breaker is advantageously designed so that the control unit continuously monitors the charge signal and, in the event of a discharge of the energy storage device, determines, and in particular measures, the discharge time. In this way, the electronic circuit breaker reacts to the potential discharge of the energy storage device at any time during the intended operation of the circuit.

[0013] Ideally, the load current should be direct current. Arc faults are particularly problematic in DC systems. Unlike AC systems, the supply voltage US never has a zero crossing that could extinguish an arc fault, especially a series arc fault.

[0014] If the voltage source provides the supply voltage US as a DC voltage, the load current in the circuit also flows as a DC current. Modern DC electrical systems are increasingly designed for higher supply voltages US to improve energy efficiency. However, the higher the supplied DC voltage, the greater the risk of arcing faults, particularly in series. Furthermore, an arcing fault, especially in series, persists in a DC system.

[0015] The discharge of the energy storage device effectively prevents the formation of an arc fault when the actuator is closed. During normal operation of the circuit, the energy storage device of the electronic circuit breaker maintains a load operating voltage UA. The energy storage device can also be integrated separately from the electronic circuit breaker into the load. This maintenance reduces the voltage drop between the voltage source and the electronic circuit breaker. The reduced voltage drop is lower than the ignition voltage of an arc fault, particularly a series arc fault.

[0016] In a further advantageous development, the limit value for the discharge time is chosen such that the actuator is switched to the open state before a series arc fault occurs. Specifically, the limit value is chosen such that the discharge beginning before the series arc fault occurs already exceeds the limit value.

[0017] In a more advantageous development, the energy storage device is a capacitor or a battery. The capacitor can be a supercapacitor or an electrolytic capacitor. The battery can also be a rechargeable battery.

[0018] Advantageously, the electronic circuit breaker includes a DC / DC converter positioned between the energy storage device and the power supply. The DC / DC converter decouples the energy storage device's operating voltage (Ue) from the power supply voltage (USs). The DC / DC converter can have a wide operating range, which allows for better utilization of the electrical energy stored in the energy storage device.

[0019] Advantageously, the electronic circuit breaker includes an energy management unit arranged between the energy storage device and the current path. In particular, the energy management unit is designed to allow the energy storage device to discharge when the difference between the operating voltage Ue of the energy storage device (normalized, in particular, by means of a conversion factor) and the voltage Uin at the input exceeds an upper differential threshold.

[0020] For discharge to occur, the normalized operating voltage of the energy storage device must be higher than the voltage at the input of the electronic circuit breaker by the upper differential threshold value. This upper differential threshold value could, for example, be 2V. In other words, the energy management unit only initiates discharge of the energy storage device when the input voltage drops significantly.

[0021] The conversion factor has a value of 1 when the operating voltage of the energy storage device is equal to the voltage at the input of the electronic circuit breaker. If the operating voltage of the energy storage device differs from the voltage at the input of the electronic circuit breaker, the conversion factor has a value other than 1. For example, the DC / DC converter can convert the voltage at the input of the electronic circuit breaker to twice the operating voltage of the energy storage device. In this case, the actual operating voltage of the energy storage device must be halved for calculation purposes, i.e., divided by a conversion factor of 2. Specifically, the conversion factor corresponds to the factor by which the DC / DC converter scales the voltage at the input of the electronic circuit breaker. In particular, the conversion factor corresponds to the quotient of the operating voltage of the energy storage device and the voltage at the input of the electronic circuit breaker during normal operation.

[0022] Preferably, the energy management unit is designed to prevent discharge of the energy storage device when the difference between the energy storage device's operating voltage Ue (normalized, in particular, by a conversion factor) and the input voltage Uin is less than a lower differential threshold. For discharge to occur, the normalized operating voltage of the energy storage device must therefore be at least this lower differential threshold higher than the input voltage of the electronic circuit breaker. The lower differential threshold could, for example, be 0.3 V. In other words, the energy management unit stops the discharge of the energy storage device when its operating voltage, as a result of the discharge, approaches the input voltage.

[0023] In particular, the energy management unit allows the energy storage to discharge as long as the difference between the supply voltage US of the circuit and the input voltage Uin of the electronic circuit breaker is less than an arc fault limit USLBmin. The arc fault limit USLBmin can be the sum of an offset value Uoffset and the voltage drop value between a voltage source generating the supply voltage and the input, where the offset value is typically between 10 V and 14 V. The voltage drop value corresponds to the voltage drop across an electrical line with line resistance RW between the voltage source and the electronic circuit breaker, i.e., USLBmin = Rw Iin + Uoffset, where Iin denotes the input current of the electronic circuit breaker. The line resistance RW can be measured or estimated.

[0024] The charging signal is conveniently represented as an operating voltage or discharge current of the energy storage device. The operating voltage Ue or the discharge current ie can be easily determined by the control unit.

[0025] In a beneficial further development, the limit for the discharge time is between 5 ms and 25 ms, particularly between 10 ms and 20 ms. Limits within this range have proven effective in practice.

[0026] A circuit arrangement according to the invention comprises a voltage source and a load. The voltage source is, for example, designed as a DC power supply or a bus of a DC network. The load can also be referred to as an electrical load or a resistive load.

[0027] According to the invention, the circuit arrangement comprises an electronic circuit breaker according to one embodiment of the invention. The electronic circuit breaker is preferably arranged in close proximity to the load. The input of the electronic circuit breaker is connected to the voltage source. The output of the electronic circuit breaker is connected to the load. In particular, the electronic circuit breaker is arranged closer to the load than to the voltage source along a connecting line running from the voltage source to the load. Advantageously, the distance measured along the connecting line between the voltage source and the input is at least twice as large as the distance measured along the connecting line between the output and the load.In a further development, the electronic circuit breaker can comprise multiple inputs, multiple energy storage devices, multiple actuators, and multiple outputs; i.e., it can be multi-channel. During normal operation of the circuit, the electronic circuit breaker prevents the formation of a series arc fault, thereby protecting the electrical conductor and / or the load from damage or destruction caused by such an arc fault.

[0028] In one embodiment, the circuit arrangement comprises an electrical conductor connecting the voltage source and the load, and the electronic circuit breaker is arranged in an end section of the electrical conductor facing away from the voltage source. Unlike conventional electronic circuit breakers, the electronic circuit breaker according to the invention is located downstream of the electrical conductor, as the component of the circuit to be protected, when viewed from the voltage source. In particular, the electronic circuit breaker is arranged along the electrical conductor closer to the load than to the voltage source. Advantageously, the electronic circuit breaker is arranged in the quarter of the electrical conductor furthest from the voltage source.

[0029] In a further advantageous embodiment, the circuit arrangement comprises a higher-level electronic circuit breaker located between the voltage source and the electronic circuit breaker. The higher-level electronic circuit breaker is preferably located in close proximity to the voltage source. In particular, the higher-level electronic circuit breaker is located closer to the voltage source along the connecting line than the electronic circuit breaker. Advantageously, the higher-level electronic circuit breaker is integrated into the voltage source.

[0030] When the discharge time limit is exceeded, the control unit sends a disconnect signal to the upstream electronic circuit breaker, instead of switching the actuator to the open state. This disconnects the electronic circuit breaker from the voltage source via the upstream circuit breaker. The electronic circuit breaker and the upstream circuit breaker together form a cascaded protection system. The two electronic circuit breakers are located at opposite ends of the electrical line between the voltage source and the load. The electronic circuit breaker trips the upstream electronic circuit breaker.While the electronic circuit breaker according to the invention protects the electrical line and / or the load, in particular against series arc faults, the upstream electronic circuit breaker protects the electrical line and / or the load, in particular against parallel arc faults (PSLB). In particular, the upstream electronic circuit breaker also provides protection against overload, short circuit, or earth fault.

[0031] Alternatively, the control unit can activate a chopper of the electronic circuit breaker. The electronic circuit breaker causes the chopper to create a short circuit. The upstream electronic circuit breaker detects the short circuit created by the chopper and then automatically disconnects the electrical line from the voltage source. In conjunction with the upstream electronic circuit breaker, the electronic circuit breaker therefore also provides protection against parallel arc faults that would not be detected by the upstream electronic circuit breaker alone.

[0032] An inventive method for preventing, in particular, a series arc fault in a circuit by means of an electronic circuit breaker, wherein the electronic circuit breaker has a current path that is looped into the circuit, comprises the following steps:

[0033] According to the invention, a charge signal is monitored, the change of which correlates with a change in the charge of a charged energy storage device of the electronic circuit breaker. When a discharge of the energy storage device is detected based on the charge signal while the current path is closed, a discharge time, during which the energy storage device is continuously discharged, is determined, and in particular measured. Advantageously, the discharge is detected by a control unit. The determination, and in particular the measurement, of the discharge time is expediently carried out by the control unit. If a limit value for the discharge time is exceeded, the current path is opened. Advantageously, the control unit causes the current path to be opened. In particular, an actuator is arranged in the current path that can be opened to open the current path, preventing the load current from passing through the actuator.Opening the current path prevents the formation of a series arc fault in the circuit. This method protects an electrical line connected to the input of the electronic circuit breaker and / or a load connected to an output of the electronic circuit breaker from damage or destruction caused by a series arc fault.

[0034] An embodiment of the invention is explained below with reference to the drawing. The drawing shows: Fig. 1 a circuit arrangement from the prior art, Fig. 2 the in Fig. 1 The circuit arrangement shown with a series arc fault, Fig. 3 a circuit diagram of an electronic protective switch according to the invention, Fig. 4 a circuit arrangement according to the invention; Fig. 5 the in Fig. 4 Circuit arrangement shown with arcing faults.

[0035] Fig. 1Figure 15 shows a known circuit arrangement. The circuit arrangement 15 comprises a voltage source 11, an electrical line 14, a conventional electronic circuit breaker 16, and a load 12. The conventional electronic circuit breaker 16 is located in one end section of the electrical line 14 facing the voltage source 11. The voltage source 11 has an internal resistance RS and provides a supply voltage US. The symbol Ri is also commonly used for internal resistance. The electrical line 14 has a line resistance RW. The load 12 has a load resistance RL. In the intended operation of the circuit arrangement 15, the electronic circuit breaker 16 is in a closed state, connecting the load 12 to the voltage source 11 and allowing a load current to pass through.

[0036] Fig. 2 shows the in Fig. 1The circuit arrangement 15 shown features a series arc fault 17, which arises, for example, from a break in the electrical conductor 14. The break divides the conductor resistance RW into a first conductor resistance R Wa between the voltage source 11 and the break point, and a second conductor resistance R Wb between the break point and the electronic circuit breaker 16, where RW = R Wa + R Wb. An arc fault voltage U SLB, which sustains the series arc fault 17, drops across the break point. The conventional electronic circuit breaker 16 does not detect the arc fault voltage U SLB and, consequently, the series arc fault 17. As a result, the circuit breaker 16 does not open and does not disconnect the load 12 from the voltage source 11.The load current, which continues to pass through the electronic circuit breaker 16 and is modulated by the series arc fault 17, can damage or even destroy the electrical line 14 or the load 12. Furthermore, the series arc fault 17 can cause a fire.

[0037] Fig. 3 Figure 1 shows an electronic circuit breaker 1 according to the invention. The electronic circuit breaker 1 according to the invention can be used in place of the conventional electronic circuit breaker 16 in the Figures 1 and 2 The circuit arrangement shown in section 15 is arranged as follows. The description of the... Figures 1 and 2This also applies to a circuit arrangement according to the invention. The electronic circuit breaker 1 according to the invention has an input 2 and an output 3. A current path 4 for a load current runs between the input 2 and the output 3. The load current can be a direct current. An input voltage applied to the input 2 is denoted by Uin.

[0038] An actuator 5 is arranged in the current path 4. The actuator 5 has a closed state and an open state. In the open state, the current path 4 is open and blocks the load current. In the closed state, the current path 4 is closed and allows the load current to pass. The actuator 5 serves to interrupt and close the current path 4.

[0039] The electronic circuit breaker 1 includes a control unit 6. The control unit 6 is designed to switch the actuator 5 between the open state and the closed state.

[0040] The electronic circuit breaker 1 includes an energy storage device 7, which is electrically connected to the current path 4. The energy storage device 7 can be a capacitor or a battery. An operating voltage provided by the energy storage device 7 is denoted by Ue. A current flowing during a charge change of the energy storage device 7 is denoted by ie. The electronic circuit breaker 1 is designed such that a discharge and / or charge of the energy storage device 7 is possible during the intended operation of the electronic circuit breaker 1, in particular when the current path 4 is closed, and especially when the actuator 5 is in the closed state.

[0041] The electronic circuit breaker 1 is designed such that, when the electronic circuit breaker 1 is installed in a circuit 8 for the transmission of the load current through the current path 4 of the control unit 6, a charge signal is transmitted, the change of which correlates with a change in the charge of the charged energy storage device 7. The charge signal can be an operating voltage of the energy storage device 7 or a discharge current of the energy storage device 7. The charge signal is monitored during the intended operation of the electronic circuit breaker 1, i.e., when the load is supplied with the load current. In particular, the charge signal is continuously monitored.

[0042] The electronic circuit breaker 1 is further designed such that, when the energy storage device 7 is discharged based on the charge signal, the control unit 6 determines a discharge time, in the exemplary embodiment measures it, during which the energy storage device 7 is continuously discharged, and that the control unit 6 switches the actuator 5 to the open state when a limit value for the discharge time is exceeded.

[0043] The discharge time limit is selected such that the actuator 5 switches to the open state before a series arc fault occurs. Specifically, the discharge time limit can be from 5 ms to 25 ms, and in particular from 10 ms to 20 ms. This prevents the formation of a series arc fault in circuit 8.

[0044] Furthermore, the formation of the arc fault, especially serial arc faults, when the actuator 5 is closed can be prevented by discharging the energy storage device 7.

[0045] The electronic circuit breaker 1 can be designed so that the control unit 6 continuously monitors the charge signal and, in the event of a discharge of the energy storage device 7, determines, in particular measures, the discharge time.

[0046] Furthermore, the electronic circuit breaker 1 can include a DC-DC converter 9, which is arranged between the energy storage device 7 and the current path 4.

[0047] The electronic circuit breaker 1 includes, in particular, an energy management unit 10 arranged between the energy storage device 7 and the current path 4. The energy management unit 10 can be configured to allow the energy storage device 7 to discharge if the difference between the operating voltage of the energy storage device 7 and the input voltage at input 2, normalized in particular by means of a conversion factor, is greater than an upper differential threshold. The energy management unit 10 can also be configured to block the energy storage device 7 from discharging if the difference between the operating voltage of the energy storage device 7, normalized in particular by means of a conversion factor, and the input voltage at input 2 is less than a lower differential threshold.In particular, the DC / DC converter allows the energy storage device 7 to be discharged during the intended operation of the electronic circuit breaker 1, especially when the current path 4 is closed.

[0048] In particular, the energy management unit 10 allows the energy storage device 7 to discharge as long as the difference between the supply voltage of the circuit 8 and the input voltage of the electronic circuit breaker 1 is less than an arc fault limit. Ideally, the arc fault limit corresponds to the sum of an offset value and the voltage drop value between a voltage source 11 generating the supply voltage and the input 2. The offset value is, in particular, between 10 V and 14 V.

[0049] The electronic circuit breaker 1 may also include a chopper 13 and / or a fuse 19. The fuse 19 may be provided to comply with an applicable safety standard.

[0050] The electronic circuit breaker 1 can also include a communication module 22 and / or a measuring module 24, which are functionally connected to the control unit 6. The communication module 22 is configured to transmit a state of the electronic circuit breaker 1 and / or the circuit 8 to a central control system (not shown). The measuring module 23 is configured to detect a state of the circuit 8 by measuring the current of the load current or an input voltage U. The electronic circuit breaker 1 can further include a control module 23, which is functionally connected to the control unit 6 and the actuator 5. The control module 23 is configured to open or close the actuator 5 depending on a signal from the control unit 6.

[0051] Fig. 4Figure 1 shows a circuit arrangement 20 according to the invention. The circuit arrangement 20 comprises a voltage source 11 and a load 12. The circuit arrangement 20 further comprises the [missing information]. Fig. 3 The electronic circuit breaker 1 shown. The input 2 of the electronic circuit breaker 1 is connected to the voltage source 11 via an electrical line. The output 3 of the electronic circuit breaker 1 is connected to the load 12. The electronic circuit breaker 1 can be arranged in an end section of the electrical line furthest from the voltage source 11. In particular, the electronic circuit breaker 1 is arranged along the electrical line closer to the load 12 than to the voltage source 11. Advantageously, the electronic circuit breaker 1 is arranged in the quarter of the electrical line furthest from the voltage source 11.

[0052] The circuit arrangement 20 further includes a superior electronic circuit breaker 21, which functions as a conventional electronic circuit breaker 16 (see Figures 1 and 2The upstream electronic circuit breaker 21 can be configured as a conductor and is arranged between the voltage source 11 and the electronic circuit breaker 1. The upstream electronic circuit breaker 21 can be arranged in an end section of the electrical line facing the voltage source 11. In particular, the upstream electronic circuit breaker 21 is arranged along the electrical line closer to the voltage source 11 than to the load 12. Advantageously, the upstream electronic circuit breaker 21 is arranged in a quarter of the electrical line furthest from the load 12.The control unit 6 can, when the limit value for the discharge time is exceeded, in particular instead of switching the actuator 5 to the open state, send a disconnect signal to the higher-level electronic circuit breaker 21 to activate the higher-level electronic circuit breaker 21, thereby disconnecting the electronic circuit breaker 1 from the voltage source 11 by the higher-level circuit breaker 21.

[0053] Alternatively or additionally, the control unit 6 activates, in particular instead of the one in Fig. 3 The actuator 5 shown is switched to the open state, the chopper 13 of the electronic circuit breaker 1, whereby the higher-level electronic circuit breaker 21 detects an overload case and disconnects the electronic circuit breaker 1 from the voltage source 11.

[0054] By means of the electronic circuit breaker 1, whose current path 4 is inserted into the circuit 8, a particularly series arc fault in the circuit 8 is prevented in a method as follows.

[0055] A charge signal is monitored, the change of which correlates with a change in the charge of the charged energy storage device 7 of the electronic circuit breaker 1. In the exemplary embodiment, the monitoring is carried out by the control unit 6 as described above.

[0056] When the energy storage device 7 is discharged based on the charge signal while the current path 4 is closed, a discharge time is determined, in particular measured, during which the energy storage device 7 is continuously discharged. In the exemplary embodiment, the determination, in particular the measurement of the discharge time, is carried out by the control unit 6.

[0057] If the discharge time limit is exceeded, the current path 4 is opened, thereby preventing the formation of a fault arc, particularly a series arc, in the circuit 8. In the exemplary embodiment, the opening of the current path 4 is effected by the control unit 6. As described above, the actuator 5 is advantageously switched to the open state for this purpose.

[0058] Furthermore, the formation of an arc fault, in particular a serial arc fault, can be prevented by discharging the energy storage device 7.

[0059] Fig. 5 shows the in Fig. 4The circuit arrangement 20 shown. Thanks to the electronic circuit breaker 1, the circuit arrangement 20 protects the electrical line 14 and / or the load 12 from series arc faults 17 in the electrical line 14, both in the supply and return lines, or from a parallel arc fault 18 between the supply and return lines. The series arc faults 17 are each accompanied by an arc fault voltage USLB. The electronic circuit breaker 1 prevents the series arc faults 17 from occurring by disconnecting the load 12 from the voltage source 11. The upstream electronic circuit breaker 21 also detects the parallel arc fault 18 and causes the upstream electronic circuit breaker 21 to disconnect the electrical line 14 from the voltage source 11, thereby extinguishing the parallel arc fault 18.

Claims

1. Electronic circuit breaker having an input (2) and an output (3), wherein a current path (4) for a load current runs between the input (2) and the output (3), wherein an actuator (5), which has a closed state and an open state, is arranged in the current path (4), wherein, in the open state, the current path (4) is open and blocks the load current, wherein, in the closed state, the current path (4) is closed and allows the load current to pass, wherein the electronic circuit breaker (1) comprises a control unit (6) designed to switch the actuator (5) between the open state and the closed state, characterized in that the electronic circuit breaker (1) comprises an energy storage device (7), which is electrically connected to the current path (4), in that the electronic circuit breaker (1) is designed such that, when the electronic circuit breaker (1) is arranged in a circuit (8) for conducting the load current through the current path (4), - a charge signal is transmitted to the control unit (6), the change in which charge signal correlates to a change in charge of the charged energy storage device (7), - if it is detected based on the charge signal that the energy storage device (7) has been discharged, the control unit (6) measures a discharge time when the actuator (5) is in the closed state, during which discharge time the energy storage device (7) is continuously discharged, and - the control unit (6) switches the actuator (5) to the open state when a limit value for the discharge time is exceeded, thereby preventing formation of an arc fault in the circuit (8).

2. Electronic circuit breaker according to Claim 1, characterized in that the electronic circuit breaker (1) is designed such that the control unit (6) continuously monitors the charge signal and determines the discharge time in the event of a discharge of the energy storage device (7).

3. Electronic circuit breaker according to Claim 1 or 2, characterized in that the load current is a direct current.

4. Electronic circuit breaker according to any of Claims 1 to 3, characterized in that the formation of the arc fault is prevented by discharging the energy storage device (7) when the actuator (5) is in the closed state.

5. Electronic circuit breaker according to any of Claims 1 to 4, characterized in that the limit value for the discharge time is selected such that the actuator (5) is switched to the open state even before the arc fault can form.

6. Electronic circuit breaker according to any of Claims 1 to 5, characterized in that the energy storage device (7) is a capacitor or a rechargeable battery.

7. Electronic circuit breaker according to any of Claims 1 to 6, characterized in that the electronic circuit breaker (1) comprises a DC-DC converter (9), which is arranged between the energy storage device (7) and the current path (4).

8. Electronic circuit breaker according to any of Claims 1 to 7, characterized in that the electronic circuit breaker (1) has an energy management unit (10), which is arranged between the energy storage device (7) and the current path (4), in that the energy management unit (10) is designed such that it allows the energy storage device (7) to be discharged if a difference between the operating voltage of the energy storage device (7), which in particular is normalized by means of a conversion factor, and the voltage at the input (2) is greater than an upper difference threshold value.

9. Electronic circuit breaker according to Claim 8, characterized in that the energy management unit (10) is designed such that it blocks the energy storage device (7) being discharged if the difference between the operating voltage of the energy storage device (7), which in particular is normalized by means of a conversion factor, and the voltage at the input (2) is less than a lower difference threshold value.

10. Electronic circuit breaker according to Claim 8 or 9, characterized in that the energy management unit (10) allows the energy storage device (7) to be discharged as long as the difference between a supply voltage of the circuit (8) and the input voltage of the electronic circuit breaker (1) is less than an arc fault limit value, wherein the arc fault limit value corresponds to the sum of an offset value and the voltage loss value of the voltage loss between a voltage source (11) generating the supply voltage and the input (2), wherein the offset value is in particular from 10 V to 14 V.

11. Electronic circuit breaker according to any of Claims 1 to 10, characterized in that the charge signal is a voltage of the energy storage device (7) or a discharge current of the energy storage device (7).

12. Electronic circuit breaker according to any of Claims 1 to 11, characterized in that the limit value for the discharge time is from 5 ms to 25 ms, in particular from 10 ms to 20 ms.

13. Circuit arrangement comprising a voltage source (11) and a load (12), characterized in that the circuit arrangement (20) comprises an electronic circuit breaker (1) according to any of Claims 1 to 12, in that the input (2) of the electronic circuit breaker (1) is connected to the voltage source (11), and in that the output (3) of the electronic circuit breaker (1) is connected to the load (12).

14. Circuit arrangement according to Claim 13, characterized in that the circuit arrangement (20) comprises an electrical line connecting the voltage source (11) and the load (12), and the electronic circuit breaker (1) is arranged in an end section of the electrical line remote from the voltage source.

15. Circuit arrangement according to Claim 13 or 14, characterized in that the circuit arrangement (20) comprises a higher-level electronic circuit breaker (21), which is arranged between the voltage source (11) and the electronic circuit breaker (1), and in that the control unit (6), when the limit value for the discharge time is exceeded, in particular instead of switching the actuator (5) into the open state, - sends a disconnection signal for activating the higher-level electronic circuit breaker (21) to the higher-level electronic circuit breaker (21), as a result of which the electronic circuit breaker (1) is disconnected from the voltage source (11) by way of the higher-level circuit breaker (21), or - activates a chopper (13) of the electronic circuit breaker (1), as a result of which the higher-level electronic circuit breaker (21) detects an overload situation and disconnects the electronic circuit breaker (1) from the voltage source (11).

16. Method for preventing an arc fault in a circuit (8) by means of an electronic circuit breaker (1), wherein the electronic circuit breaker (1) has a current path looped into the circuit (8), wherein, in the method, - a charge signal is monitored, the change in which correlates to a change in charge of a charged energy storage device (7) of the electronic circuit breaker (1), - if it is detected based on the charge signal that the energy storage device (7) has been discharged, a discharge time is determined when the current path is in the closed state, during which discharge time the energy storage device (7) is continuously discharged, and - the current path is opened when a limit value for the discharge time is exceeded, thereby preventing formation of an arc fault in the circuit (8).