Devices, circuit breakers and pre-charging devices for DC power supply networks

Abstract

The invention discloses a device (1a..1l) with a circuit breaker (20) and a precharging device (21), wherein two series capacitors (C1, C2) are connected to a direct current power supply network (DC), and wherein the device (1a..1l) comprises: a circuit breaker control unit (SCU) designed to open the circuit breaker (S in the event of an overcurrent and / or upon manual intervention. C ); a load control unit (LCU) designed to limit the load current of the two series capacitors (C1, C2) by using a high-ohmic path (4); and a balancing control unit (BCU) designed to measure the capacitor voltage (V1, V2) of each of the two series capacitors (C1, C2) and avoid or limit an imbalance of these capacitor voltages (V1, V2) by individually controlling the current through the two series capacitors (C1, C2).

Description

Technical Field

[0001] The present invention relates to a device, comprising a direct current power supply network (referred to as "DC power supply network" for short) having a positive pole and a negative pole, two capacitors in series, wherein a first external tap is connected to the positive pole via a first power line, wherein a second external tap is connected to the negative pole via a second power line, and wherein an intermediate tap is connected to ground. In addition, the device comprises a circuit switch arranged in at least one of the first and second power lines and a circuit switch control unit, which is designed to disconnect the circuit switch in the event of an overcurrent and / or upon manual intervention. In addition, the present invention relates to a circuit breaker, the circuit breaker comprising a first circuit breaker input terminal for connecting the positive pole of the direct current power supply network and a second circuit breaker input terminal for connecting the negative pole of the direct current power supply network, and a first circuit breaker output terminal for connecting the first external taps of the two capacitors in series and a second circuit breaker output terminal for connecting the second external taps of the two capacitors in series. A first circuit breaker current path of the circuit breaker connects the first circuit breaker input terminal and the first circuit breaker output terminal, and a second circuit breaker current path of the circuit breaker connects the second circuit breaker input terminal and the second circuit breaker output terminal. In addition, the circuit breaker comprises a circuit switch arranged in at least one of the first and second circuit breaker paths and a circuit switch control unit, which is designed to disconnect the circuit switch in the event of an overcurrent and / or upon manual intervention. Finally, the present invention relates to a precharging device, which comprises a first precharger input terminal for connecting the positive pole of a DC power supply network and a second precharger input terminal for connecting the negative pole of the DC power supply network, as well as a first precharger output terminal for connecting the first external tap of two series capacitors and a second precharger output terminal for connecting the second external tap of two series capacitors. In addition, the precharging device comprises a first precharger current path and a second precharger current path, the first precharger current path connecting the first precharger input terminal and the first precharger output terminal, and the second precharger current path connecting the second precharger input terminal and the second precharger output terminal. Background Art

[0002] Devices, circuit breakers and pre-charging circuits of the type disclosed above are known in principle. The capacitors act as energy buffers, which may cause problems in transition phases between different operating states. In particular, overcurrent conditions in the circuit breaker may be caused, which in turn leads to disconnection from the DC power supply network. In addition, in the prior art, there is a lack of solutions for (floating) DC power supply networks, as well as more general solutions covering all necessary aspects of connecting capacitors to a DC power supply network via circuit breakers. Summary of the invention

[0003] It is therefore an object of the present invention to provide an improved device, an improved circuit breaker and an improved pre-charging circuit. In particular, a solution will be provided which covers all necessary aspects of connecting a capacitor to a DC power supply network, more particularly a floating DC power supply network, via a circuit breaker, wherein neither the positive nor the negative pole is directly connected to ground.

[0004] The objects of the invention are solved by a device as disclosed in the opening paragraph, said device additionally comprising

[0005] - a switchable high-ohmic path in at least one of said first and said second power supply lines, said switchable high-ohmic path bypassing a) a switchable low-ohmic path in said at least one of said first and said second power supply lines or b) said circuit switch,

[0006] a load control unit designed to measure the total voltage of the two series capacitors and, if the measured total voltage is below a first threshold voltage, to switch on the high-ohmic path and to switch off the low-ohmic path in case a) and to switch on the high-ohmic path and to switch off the circuit switch in case b) if the measured total voltage is below a first threshold voltage, and to switch on the low-ohmic path (and in particular also switch off the high-ohmic path) in case a) or to switch on the circuit switch (and in particular also switch off the high-ohmic path) in case b) if the measured total voltage is equal to or above the first threshold voltage or above a second, higher threshold voltage, wherein the first threshold voltage and, if present, the second threshold voltage are arranged to be lower than the voltage of the DC power supply network between its positive and negative poles, and

[0007] - a balancing control unit designed to measure the capacitor voltage of each of the two series capacitors, detect an imbalance of these capacitor voltages and individually control the current through the two series capacitors by using a first current influencing member, wherein if the first capacitor voltage of a first capacitor of the two series capacitors is lower than the second capacitor voltage of a second capacitor of the two series capacitors, the current through the first capacitor is higher than the current through the second capacitor, and vice versa.

[0008] The objects of the invention are furthermore solved by a circuit breaker as disclosed in the opening paragraph, said circuit breaker further comprising

[0009] - a switchable high-ohmic path in at least one of said first and said second circuit breaker current paths, said switchable high-ohmic path bypassing either a) a switchable low-ohmic path in said at least one of said first and said second circuit breaker current paths or b) said circuit switch,

[0010] a load control unit designed to measure the total voltage between the first circuit breaker output terminal and the second circuit breaker output terminal and, if the measured total voltage is below a first threshold voltage, to switch on the high-ohmic path and to switch off the low-ohmic path in case a) and to switch on the high-ohmic path and to switch off the circuit switch in case b) if the measured total voltage is below a first threshold voltage, and to switch on the low-ohmic path (and in particular to switch off the high-ohmic path) in case a) or to switch on the circuit switch (and in particular to switch off the high-ohmic path) in case b) if the measured total voltage is equal to or above the first threshold voltage or above a second, higher threshold voltage, wherein the first threshold voltage and, when present, the second threshold voltage are set below a nominal voltage which can be applied to the first circuit breaker input terminal and the second circuit breaker input terminal, and / or

[0011] - a third circuit breaker output terminal, the third circuit breaker output terminal being used to connect a center tap of the two series capacitors and a balancing control unit, the balancing control unit being designed to measure a first voltage between the first circuit breaker output terminal and the third circuit breaker output terminal and a second voltage between the third circuit breaker output terminal and the second circuit breaker output terminal, detect an imbalance between the first and second voltages and individually control the current through the first circuit breaker output terminal and the second circuit breaker output terminal, wherein if the first voltage is lower than the second voltage, the current through the first circuit breaker output terminal is higher than the current through the second circuit breaker output terminal, and vice versa.

[0012] The object of the present invention is ultimately solved by a pre-charging device as disclosed in the opening paragraph, which pre-charging device further comprises

[0013] - a switchable high-ohmic path in at least one of the first and the second pre-charger current paths, the switchable high-ohmic path bypassing a switchable low-ohmic path in at least one of the first and the second pre-charger current paths and a load control unit, the load control unit being designed to measure the total voltage between the first pre-charger output terminal and the second pre-charger output terminal and to switch the high-ohmic path on and off the low-ohmic path if the measured total voltage is below a first threshold voltage, and to switch the low-ohmic path on (and in particular to switch off the high-ohmic path) if the measured total voltage is equal to or above the first threshold voltage or above a second, higher threshold voltage, wherein the first threshold voltage and, when present, the second threshold voltage are set below a nominal voltage which can be applied to the first pre-charger input terminal and the second pre-charger input terminal, and / or

[0014] - A third circuit breaker output terminal, the third precharger output terminal being used to connect the middle tap of the two series capacitors and a balancing control unit, the balancing control unit being designed to measure a first voltage between the first precharger output terminal and the third precharger output terminal and a second voltage between the third precharger output terminal and the second precharger output terminal, detect an imbalance between the first and second voltages and individually control the current through the first precharger output terminal and the second precharger output terminal, wherein if the first voltage is lower than the second voltage, the current through the first precharger output terminal is higher than the current through the second precharger output terminal, and vice versa.

[0015] By the above measures, any load current loading the capacitor is limited and any imbalance of the capacitor voltage is avoided or at least reduced. Thus, overcurrent conditions in the circuit breaker are avoided and the circuit switch is not triggered by the load current of the capacitor. In addition, the voltage of the DC power supply network is symmetrical about ground. Therefore, the voltage of the DC power supply network does not float arbitrarily.

[0016] In the context of the present invention, "ground" may refer to a common reference potential of a plurality of DC power supply networks and / or an earth potential of a single DC power supply network or a plurality of DC power supply networks.

[0017] Further advantageous embodiments are disclosed in the claims and the description as well as in the drawings.

[0018] Advantageously, the switchable high-ohmic path comprises a switch and a series resistor or a second current influencing member, which allows more than two control values ​​in the current range (with or without a switch, in particular with a current range starting from zero). Thus, the resistance of the high-ohmic path can be switched or varied between two values ​​(on / off) or multiple values.

[0019] In this context it should be noted that, considering a low-ohmic path, "switchable" generally means switchable between two values ​​(on / off). The switch in the low-ohmic path can, for example, be embodied as an electronic switch (for example, by using a transistor) or an electromechanical switch (for example, as a relay). Considering a high-ohmic path, "switchable" can mean the same or, for example, a current source, whose current range starts in particular (but not necessarily) from zero or almost zero. In the present context, "almost zero" especially refers to 10% of the current range. Even if the high-ohmic path comprises a current source, there may be additional switches connected in series.

[0020] In an advantageous embodiment of the device, the first current influencing member comprises a first sub-current influencing member switched in parallel with the first capacitor and a second sub-current influencing member switched in parallel with the second capacitor. Thus, in an advantageous embodiment of the circuit breaker, the first current influencing member comprises a first sub-current influencing member switched between the first circuit breaker output terminal and the third circuit breaker output terminal and a second sub-current influencing member switched between the third circuit breaker output terminal and the second circuit breaker output terminal. Thus, in an advantageous embodiment of the pre-charging device, the first current influencing member comprises a first sub-current influencing member switched between the first pre-charger output terminal and the third pre-charger output terminal and a second sub-current influencing member switched between the third pre-charger output terminal and the second pre-charger output terminal. In this way, the currents through the capacitors can be controlled independently of each other.

[0021] In a further advantageous embodiment of the device, the first current influencing member comprises a first sub-current influencing member and a second sub-current influencing member, wherein the first sub-current influencing member is arranged in a first switchable high-ohmic path in the first power line, which first switchable high-ohmic path bypasses a) a first switchable low-ohmic path in the first power line or b) a circuit switch in the first power line, and wherein the second sub-current influencing member is arranged in a second switchable high-ohmic path in the second power line, which second switchable high-ohmic path bypasses the second switchable low-ohmic path in the second power line in case a) or bypasses the complementary circuit switch in the second power line in case b). Therefore, in a preferred embodiment of the circuit breaker, the first current influencing member comprises a first sub-current influencing member and a second sub-current influencing member, wherein the first sub-current influencing member is arranged in a first switchable high-ohmic path in the first circuit breaker current path, which first switchable high-ohmic path bypasses a) a first switchable low-ohmic path in the first circuit breaker current path or b) a circuit switch in the first circuit breaker current path, and wherein the second sub-current influencing member is arranged in a second switchable high-ohmic path in the second circuit breaker current path, which second switchable high-ohmic path bypasses the second switchable low-ohmic path in the second circuit breaker current path in case a) or bypasses the complementary circuit switch in the second circuit breaker current path in case b). Therefore, in an advantageous embodiment of the pre-charging device, the first current influencing member comprises a first sub-current influencing member and a second sub-current influencing member, wherein the first sub-current influencing member is arranged in a first switchable high-ohmic path in the first pre-charger current path, which first switchable high-ohmic path bypasses the first switchable low-ohmic path in the first pre-charger current path, and wherein the second sub-current influencing member is arranged in a second switchable high-ohmic path in the second pre-charger current path, which second switchable high-ohmic path bypasses the second switchable low-ohmic path in the second pre-charger current path. This is another way to control the current through the capacitor independently of each other.

[0022] In a further advantageous embodiment of the device, the load control unit is designed to keep the current through the two series capacitors below the current limit by using a first current influencing member arranged in the high-ohmic path or by using a second current influencing member arranged in the high-ohmic path. Thus, in an advantageous embodiment of the circuit breaker, the load control unit is designed to keep the current through the first circuit breaker output terminal and the second circuit breaker output terminal below the current limit by using a first current influencing member arranged in the high-ohmic path or by using a second current influencing member arranged in the high-ohmic path. Thus, in an advantageous embodiment of the pre-charging device, the load control unit is designed to keep the current through the first pre-charger output terminal and the second pre-charger output terminal below the current limit by using a first current influencing member arranged in the high-ohmic path or by using a second current influencing member arranged in the high-ohmic path. In this way, the current through the capacitor and therefore through the circuit switch is controlled, and an overcurrent condition in the circuit breaker can be avoided. For example, the capacitor can be loaded with a constant current. However, other current distributions are also possible.

[0023] Advantageously, the device comprises a discharge control unit designed to control the discharge through the two series capacitors by means of a controlled current through the first current influencing member or through a third current influencing member switched in parallel with the two series capacitors in the following cases:

[0024] - Case a): when the circuit switch is open, when the high-ohmic path and the low-ohmic path are disconnected, when the current through the circuit switch is zero or when the current through the high-ohmic path and the low-ohmic path is zero, and

[0025] - Case b): when the circuit switch is open and the high-ohmic path is off, or when the current through the circuit switch and the high-ohmic path is zero.

[0026] Therefore, the circuit breaker advantageously comprises a discharge control unit designed to control the discharge on the first circuit breaker output terminal and the second circuit breaker output terminal by means of a controlled current through the first current influencing member or through a third current influencing member switched between the first circuit breaker output terminal and the second circuit breaker output terminal in the following cases

[0027] - Case a): when the circuit switch is open, when the high-ohmic path and the low-ohmic path are disconnected, when the current through the circuit switch is zero or when the current through the high-ohmic path and the low-ohmic path is zero, and

[0028] - Case b): when the circuit switch is open and the high-ohmic path is off, or when the current through the circuit switch and the high-ohmic path is zero.

[0029] Therefore, the pre-charging device advantageously comprises a discharge control unit which is designed to control the discharge at the first pre-charger output terminal and the second pre-charger output terminal by means of a controlled current through the first current influencing member or through a third current influencing member switched between the first pre-charger output terminal and the second pre-charger output terminal in the following cases:

[0030] - Case a): when the circuit switch is open, when the high-ohmic path and the low-ohmic path are disconnected, when the current through the circuit switch is zero or when the current through the high-ohmic path and the low-ohmic path is zero, and

[0031] - Case b): when the circuit switch is open and the high-ohmic path is off, or when the current through the circuit switch and the high-ohmic path is zero.

[0032] Typically, when the aforementioned switch and current path are disconnected, not only is the capacitor disconnected from the DC power supply network, but a current drop to zero may be an indication of such disconnection. For example, such a current drop may be caused by the disconnection of an upstream circuit breaker, or if the connection to the DC power supply network is interrupted in another way, for example, by a cable interruption, such a current drop may be caused.

[0033] Advantageously, the first sub-current influencing component and the second sub-current influencing component can each be embodied as a buck converter, an electronic smoothing inductor, etc. Such components are generally available and provide reliable functioning of the device, the circuit breaker and the pre-charging device.

[0034] Advantageously, the device, the circuit breaker or the pre-charging device may include a combined balancing and discharging control unit, which performs the functions of a balancing control unit and a discharging control unit. Advantageously, the device, the circuit breaker or the pre-charging device may include a combined balancing and load control unit, which performs the functions of a balancing control unit and a load control unit. It is also beneficial if the device or the circuit breaker includes a combined circuit switch and load control unit that performs the functions of a circuit switch control unit and a load control unit. In addition, it is beneficial if the device or the circuit breaker includes a combined circuit switch balancing and load control unit that performs the functions of a circuit switch control unit, a balancing control unit and a load control unit. In addition, it is beneficial if the device or the circuit breaker includes a combined circuit switch balancing load and discharging control unit that performs the functions of a circuit switch control unit, a balancing control unit, a load control unit and a discharging control unit. All of these embodiments provide a highly integrated solution for connecting a capacitor to a DC power supply network (especially a floating DC power supply network) via a circuit breaker.

[0035] It is advantageous if the circuit breaker is connected to the pre-charging device by means of a communication channel between a circuit breaker control interface of the circuit breaker and a pre-charger control interface of the pre-charging device, wherein the communication channel is prepared to exchange information about the state of the circuit switch and / or the high-ohmic path and / or the low-ohmic path. Therefore, it is advantageous if the circuit breaker comprises a circuit breaker control interface, which is designed to be connected to a pre-charger control interface of the pre-charging device and is designed to exchange information about the state of the circuit switch and / or the high-ohmic path and / or the low-ohmic path. Therefore, it is also advantageous if the pre-charging device comprises a pre-charger control interface, which is designed to be connected to a circuit breaker control interface of the circuit breaker and is designed to exchange information about the state of the circuit switch and / or the high-ohmic path and / or the low-ohmic path. In this way, various control units can take into account the state of the circuit switch and / or the high-ohmic path and / or the low-ohmic path, even if the circuit switch and / or the high-ohmic path and / or the low-ohmic path is not part of the control unit in question. For example, if the high-ohmic path and the low-ohmic path are not part of the circuit breaker, but part of another device (e.g., a pre-charging device), there may be data communication between the circuit breaker and the device in order to obtain information about the state of the high-ohmic path and the low-ohmic path (e.g., its switching state or its current). And vice versa. For example, a discharge control unit in the pre-charging device can take into account the switching state of the circuit switch in the circuit breaker by means of the communication channel. The communication channel and the control interface can be wired or wireless. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present invention will now be described in more detail below with reference to specific examples, however the present invention is not limited to these specific examples.

[0037] Figure 1 A circuit diagram of a device having a circuit switch control circuit, a load control circuit, and a balance control circuit is shown;

[0038] Figure 2 A circuit diagram showing a device of a current source in a high ohmic path and a discharge control circuit;

[0039] Figure 3 A circuit diagram of a device having a combined balancing and discharge control circuit is shown;

[0040] Figure 4 A circuit diagram showing a device in which a high-ohmic path and its second switch are switched in parallel with the circuit switch;

[0041] Figure 5 A circuit diagram showing a device having a sub-current influencing member in a power supply line;

[0042] Figure 6A circuit diagram showing a device in which the sub-current influencing member is embodied as a buck converter;

[0043] Figure 7 shows a circuit diagram of a device having a third current influencing member and a discharge control unit for discharging a capacitor;

[0044] Figure 8 A circuit diagram showing a device in which the third current influencing member is embodied as a switch and a series resistor;

[0045] Fig. 9 A circuit diagram of an apparatus having a combined circuit switch balancing and load control unit is shown;

[0046] Fig.10 A circuit diagram of a device having a combined circuit switch balancing load and a discharge control unit is shown;

[0047] Fig.11 A circuit diagram of an apparatus having a circuit breaker is shown, and

[0048] Fig.12 A circuit diagram of a device with a circuit breaker and a pre-charging circuit is shown.

[0049] Fig.13 A first example of a solid state circuit breaker / switch is shown;

[0050] Fig.14 A second example of a solid state circuit breaker / switch is shown;

[0051] Fig.15 A third example of a solid state circuit breaker / switch is shown, and

[0052] Fig.16 A fourth example of a solid state circuit breaker / switch is shown. DETAILED DESCRIPTION

[0053] Generally, identical or similar parts are indicated by identical / similar names and reference numerals. The features disclosed in the specification apply to the parts respectively having identical / similar names and reference numerals. Indications of orientation and relative positions (upwards, downwards, sideways, etc.) relate to the associated drawings, and indications of orientation and / or relative positions must therefore be modified accordingly in the different drawings as the case may be.

[0054] Figure 1 A first example of a device 1a is shown. The device 1a comprises a direct current power supply network DC (referred to as "DC power supply network") having a positive pole + and a negative pole -, and two series capacitors C1, C2, wherein a first outer tap is connected to the positive pole + via a first power supply line 2, a second outer tap is connected to the negative pole - via a second power supply line 3, and a middle tap is connected to ground GND.

[0055] Furthermore, the device 1 a comprises an optional third capacitor C3 between the first power supply line 2 and the second power supply line 3 .

[0056] Furthermore, the device 1a comprises a circuit switch S arranged in the first power line 2 C and a circuit breaker control unit SCU designed to disconnect the circuit breaker S in the event of an overcurrent and / or upon manual intervention. C The overcurrent detection is symbolized by an ammeter A, which is designed to measure the current flowing through the circuit switch S C The current is fed to the switch control unit SCU and its output is fed to the switch control unit SCU. Manual intervention is symbolized by the manual button M. It should be noted that the ammeter A can actually be a meter connected to the electronic switch control unit SCU, but more precisely to the circuit switch S C The current detection and triggering of the circuit breaker is usually accomplished by an electric actuator and / or a thermal actuator. In the context of the present disclosure, such an electric actuator and / or a thermal actuator particularly refers to a combination of an ammeter A and a switch control unit SCU. It should also be noted that the circuit switch S C The same may be arranged in the second power line 3, or even the first power line 2 and the second power line 3 may be equipped with a circuit breaker S C Or in detail, it is equipped with a circuit switch S C Switch contacts of the circuit breaker S C , the ammeter A and the circuit switching control unit SCU together form or include the circuit switching control circuit 10a.

[0057] Furthermore, the device 1a comprises a switchable high-ohmic path 4 in the first power line 2, which bypasses the switchable low-ohmic path 5 in the first power line 2 (case a). The switchable low-ohmic path 5 can be switched on and off by means of a first switch S1, and the switchable high-ohmic path 4 can be switched on and off by means of a second switch S2. Furthermore, the device 1a comprises a load control unit LCU, which is designed to measure the total voltage V of the two series capacitors C1, C2 T , and if the measured total voltage V T is lower than the first threshold voltage, the high ohmic path 4 is turned on and the low ohmic path 5 is turned off. If the measured total voltage V T is equal to or above a first threshold voltage or above a second, higher threshold voltage, the low-ohmic path 5 is switched on (and in particular also the high-ohmic path 4 is switched off). The first threshold voltage and, if present, the second threshold voltage are arranged to be lower than the voltage between the positive pole + and the negative pole - of the direct current power supply network DC. Figure 1 In the embodiment, the high-ohmic path 4 is switched in parallel with the dedicated switchable low-ohmic path 5 (case a). However, the high-ohmic path 4 can also be switched in parallel with the circuit switch SC Parallel switching (case b - see also for example Figure 4 ). In addition, in this example, the load resistor R L is arranged in the high-ohmic path 4, but the current may also be limited by other components (see, for example, Figure 2 ). In addition, the switchable high-ohmic path 4 and the switchable low-ohmic path 5 may be arranged in the second power line 3. The switchable high-ohmic path 4, the switchable low-ohmic path 5, the load control unit LCU and the circuit for measuring the total voltage V T The ammeter forms or includes the load control circuit 11a.

[0058] Finally, the device 1a comprises a balancing control unit BCU designed to measure the capacitor voltage V1, V2 of each of the two series capacitors C1, C2, detect an imbalance of these capacitor voltages V1, V2 and individually control the current through the two series capacitors C1, C2 by using a first current influencing member I1, wherein if the first capacitor voltage V1 of the first capacitor C1 is lower than the second capacitor voltage V2 of the second capacitor C2, the current through the first capacitor C1 is higher than the current through the second capacitor C2, and vice versa. In this example, the first current influencing member I1 comprises a first sub-current influencing member IS1 switched in parallel with the first capacitor C1 and a second sub-current influencing member IS2 switched in parallel with the second capacitor C2. The first sub-current influencing member IS1 and the second sub-current influencing member IS2 can be embodied as controllable current sources, for example. The first current influencing member I1, the balancing control unit BCU and the ammeter for measuring the capacitor voltages V1, V2 form or comprise a balancing control circuit 12a.

[0059] The functions of device 1a are as follows:

[0060] As long as the total voltage V T Below the first threshold voltage, the load control unit LCU switches on the high ohmic path 4 and switches off the low ohmic path 5. Therefore, any load current of the load capacitors C1, C2 is limited by the load resistor R L In addition, the balancing control unit BCU is responsible for the two capacitors C1, C2 being loaded equally so that the voltage of the DC power supply network DC is symmetrical about the ground GND. If the capacitors C1, C2 are fully loaded, this means that the total voltage V T is equal to or higher than the first threshold voltage or higher than the second higher threshold voltage, the load control unit LCU switches on the low ohmic path 5. In addition, the load control unit LCU can switch off the high ohmic path 6. Therefore, in this state, any load ( Figure 110a) is directly connected to the DC power supply network DC via a low-ohmic path 5. By these measures, an overcurrent condition in the circuit switch control circuit 10a is avoided, and the circuit switch S C Not triggered by the load current of capacitors C1 and C2.

[0061] exist Figure 1 In the example, the current through the two series capacitors C1 and C2 is divided by the load resistor R L Limitation, but this is not Figure 2 The only possibility shown in the device 1b is shown. Instead, the load control unit LCU can be designed to keep the current through the two series capacitors C1, C2 below the current limit by using a second current influencing component I2 arranged in the high-ohmic path 4. The second current influencing component I2 can be embodied as a controllable current source. For example, the current can be kept constant, but other current distributions are also applicable. It should be noted that the second current influencing component I2 here has a current range starting from zero or almost from zero, so that the second switch S2 can be omitted. However, depending on the specific circumstances, the high-ohmic path 4 may include an additional second switch S2 controlled by the load control unit LCU (see also Figure 4 ). A switchable high-ohmic path 4, a switchable low-ohmic path 5, a load control unit LCU and a circuit for measuring the total voltage V T The ammeter forms or comprises a second instance of the load control circuit 11b.

[0062] Furthermore, the device 1b comprises an optional discharge control unit DCU which is designed to operate when the circuit switch S C When the high-ohmic path 4 and the low-ohmic path 5 are both disconnected, the discharge of the two series capacitors C1, C2 is controlled by means of a controlled current through the first current influencing member I1. Alternatively or additionally, the discharge control unit DCU can be designed to control the discharge of the two series capacitors C1, C2 by means of the circuit switch S C The discharge of the two series capacitors C1, C2 is controlled when the current is zero or when the current through the high-ohmic path 4 and the low-ohmic path 5 is zero. In this way, other reasons for disconnection from the DC power supply network DC can also be detected. For example, an upstream circuit breaker can disconnect the connection to the DC power supply network DC, or the connection can be interrupted in another way, for example because of a cable break. By the above measures, when the connection to the DC power supply network DC is interrupted, the capacitors C1, C2 are automatically discharged. Therefore, when the power lines 2, 3 are considered to be disconnected, the load capacitors C1, C2 will not pose a danger. In order to obtain the circuit switch S CIn order to obtain the switching state of the high-ohmic path 4 and the low-ohmic path 5, the discharge control unit DCU is connected to the load control unit LCU. The signals between the discharge control unit DCU and the circuit switch control unit SCU or the load control unit LCU can be sent by wire or wirelessly. The first current influencing component I1 and the discharge control unit DCU form or include a discharge control circuit 13a. In addition, the balancing control circuit 12 and the discharge control circuit 13a can form a combined balancing and discharge control circuit 14a. If the switchable high-ohmic path 4 bypasses the circuit switch S C (Case b), the discharge control unit DCU can be designed to be used as the circuit switch S C When the high-ohmic path 4 is disconnected or when the circuit switch S C and the current in the high-ohmic path 4 is zero (see also Figure 4 ) controls the discharge of two series capacitors C1 and C2.

[0063] Figure 3 An example of a device 1c with a combined balancing and discharging control unit BDCU is shown, which performs the functions of a balancing control unit BCU and a discharging control unit DCU, wherein a first current influencing member I1 comprises a first sub-current influencing member IS1 switched in parallel with a first capacitor C1 and a second sub-current influencing member IS2 switched in parallel with a second capacitor C2. The first current influencing member I1, the combined balancing and discharging control unit BDCU and an ammeter for measuring the capacitor voltages V1, V2 form or comprise a combined balancing and discharging control circuit 14b.

[0064] Figure 4 An example of a device 1d is shown, in which the high-ohmic path 4 and its second switch S2 are connected to the circuit switch S C Parallel switching, the circuit switch is arranged here in the low-ohmic path 5 (case b). In this example, there is a combined circuit switch and load control unit SLCU, which performs the functions of the circuit switch control unit SCU and the load control unit LCU. However, depending on the specific situation, the circuit switch control unit SCU and the load control unit LCU can also be embodied as separate units. In this example, the combined circuit switch and load control unit SLCU (or the separate load control unit LCU) is designed to measure the total voltage V T If the voltage is lower than the first threshold voltage, the high ohmic path 4 is connected and the circuit switch S is turned off. C , and if the measured total voltage V T is equal to or higher than the first threshold voltage or higher than the second higher threshold voltage, then the circuit switch S is turned on C(and in particular shutting off the high-ohmic path 4). The high-ohmic path 4, the low-ohmic path 5, the combined circuit switch and load control unit SLCU and the circuit for measuring the total voltage V T The ammeter forms or includes a combination circuit switch and load control circuit 15.

[0065] Figure 5 The device 1e is shown with a first current influencing component I1, which also includes a first sub-current influencing component IS1 and a second sub-current influencing component IS2, but the arrangement of the first sub-current influencing component IS1 and the second sub-current influencing component IS2 is different from Figures 1 to 4 The embodiment shown is different. In detail, the first sub-current influencing member IS1 is arranged in a first switchable high-ohmic path 4a in the first power line 2, which first switchable high-ohmic path bypasses the first switchable low-ohmic path 5a in the first power line 2, and the second sub-current influencing member IS2 is arranged in a second switchable high-ohmic path 4b in the second power line 3, which second switchable high-ohmic path bypasses the second switchable low-ohmic path 5b in the second power line 3 (case a). Therefore, the first sub-current influencing member IS1 and the second sub-current influencing member IS2 are not switched in parallel with the capacitors C1, C2, but are switched in the power lines 2, 3. The first switchable low-ohmic path 5a can be switched on and off by means of the first switch S1, while the second switchable low-ohmic path 5b can be switched on and off by means of the complementary first switch S1'. It should also be noted that the first switch S1 and the complementary first switch S1' can also be switch contacts of a single switching device, which switch contacts move simultaneously.

[0066] Likewise, the load control unit LCU may be designed to keep the current through the two series capacitors C1 , C2 below a current limit by using the first current influencing member I1 . Figure 5In the example of , there is a combined balancing and load control unit BLCU, which performs the functions of a balancing control unit BCU and a load control unit LCU. This means that any current loading the capacitors C1, C2 is limited by the load control function, and any imbalance of the capacitor voltages V1, V2 is avoided or limited by the balancing control function. To this end, the combined balancing and load control unit BLCU is connected to an ammeter for measuring the capacitor voltage V1, V2 of each of the two series capacitors C1, C2, which also provides the total voltage VT as the sum of V1+V2. In addition, the combined balancing and load control unit BLCU is connected to a first switch S1, a complementary first switch S1' and a first current influencing member I1. The combined balancing and load control unit BLCU, the ammeter for measuring the capacitor voltages V1, V2, the first switch S1, the complementary first switch S1' and the first current influencing member I1 form or include a combined balancing and load control circuit 16a.

[0067] exist Figure 5 In the example shown, the first sub-current influencing component IS1 and the second sub-current influencing component IS2 are switched in parallel with the first switch S1 and the complementary first switch S1'. However, this is not a necessary condition, and in alternative embodiments, the first sub-current influencing component IS1 can be connected to the circuit switch S C The second sub-current influencing member IS2 can be switched in parallel with the complementary circuit switch S C Parallel switching (case b - see also for example Fig. 9 ).

[0068] It should also be noted that the first sub-current influencing member IS1 and the second sub-current influencing member IS2 here have a current range starting from zero or almost starting from zero, so that the second switch S2 and the complementary second switch S2' can be omitted. However, depending on the specific situation, the high-ohmic path 4a, 4b can include an additional second switch S2, S2' controlled by the load control unit LCU or the combined balancing and load control unit BLCU (see also Figure 4 ).

[0069] Figure 6A device 1f is shown, in which the first sub-current influencing member IS1 and the second sub-current influencing member IS2 are each embodied as a buck converter. In detail, the first sub-current influencing member IS1 includes a second switch S2, a first inductor L1 and a first diode D1, and the second sub-current influencing member IS2 includes a complementary second switch S2', a second inductor L2 and a second diode D2. Wherein, the second switches S2, S2' are controlled by a combined balancing and load control unit BLCU (or, as the case may be, by a separate load control unit LCU and balancing control unit BCU). The current through the first sub-current influencing member IS1 and the second sub-current influencing member IS2 can be controlled, for example, by the pulse-pause-ratio of the second switches S2, S2'. The combined balancing and load control unit BLCU, an ammeter for measuring the capacitor voltages V1, V2, the first switches S1, S1', the second switches S2, S2', the inductors L1, L2 and the diodes D1, D2 form or include a combined balancing and load control circuit 16b.

[0070] Figure 7 The device 1g is shown with a discharge control unit DCU, which is designed to be used as a circuit switch S C , S C ' is disconnected or when both the high-ohmic paths 4a, 4b and the low-ohmic paths 5a, 5b are closed, the discharge of the two series capacitors C1, C2 is controlled by means of a controlled current through a third current influencing member I3 switched in parallel with the first capacitor C1 and the second capacitor C2. Alternatively or in addition, the discharge control unit DCU can be designed to control the discharge of the two series capacitors C1, C2 by means of a controlled current through a third current influencing member I3 switched in parallel with the first capacitor C1 and the second capacitor C2. C The discharge of the two series capacitors C1, C2 is controlled when the current is zero or when the current through the high-ohmic path 4 and the low-ohmic path 5 is zero. In this way, other reasons for disconnection from the direct current power supply network DC can also be detected. For example, an upstream circuit breaker can disconnect the connection to the direct current power supply network DC, or the connection can be interrupted in another way, for example because of a cable break. By these measures, the capacitors C1, C2 are automatically discharged when the connection to the direct current power supply network DC is interrupted. Therefore, when the power supply lines 2, 3 are considered to be disconnected, the load capacitors C1, C2 do not pose a danger. In order to obtain the circuit switch S CThe discharge control unit DCU is connected to the circuit switch control unit SCU to determine the switching state of the high-ohmic path 4a, 4b and the low-ohmic path 5a, 5b, and the discharge control unit DCU is connected to the combined balancing and load control unit BLCU to obtain the state of the high-ohmic path 4a, 4b and the low-ohmic path 5a, 5b. The signals between the discharge control unit DCU and the circuit switch control unit SCU or the combined balancing and load control unit BLCU can be sent by wire or wirelessly. The third current influencing component I3 and the discharge control unit DCU form or include a discharge control circuit 13b. If the switchable high-ohmic path 4 bypasses the circuit switch S C (Case b), the discharge control unit DCU can be designed to be used as the circuit switch S C When the high-ohmic path 4 is disconnected or when the circuit switch S C and the current in the high-ohmic path 4 is zero (see also Figure 4 ) controls the discharge of two series capacitors C1 and C2.

[0071] Figure 8 A device 1h is shown with an alternative embodiment of a third current influencing member I3 comprising a discharge switch S D and the discharge resistor R D When the circuit switch S C , S C When at least one of the two is disconnected or when both the high-ohmic paths 4a, 4b and the low-ohmic paths 5a, 5b are disconnected, the discharge switch S is closed. D The third current influencing component I3 and the discharge control unit DCU form or include a discharge control circuit 13c.

[0072] Fig. 9 shows a circuit with a switch S C and complementary circuit switch S C 'The device 1i of the first sub-current influencing member IS1 and the second sub-current influencing member IS2 switched in parallel. In detail, the circuit switch S C is arranged in the first switchable low-ohmic path 5a, and the complementary circuit switch S C ' is arranged in the second switchable low-ohmic path 5b. This function is similar to Figure 5 The device 1e shown. However, in contrast, the device 1i comprises a combined circuit switch balancing and load control unit SBLCU combining the functions of a circuit switch control unit SCU, a balancing control unit BCU and a load control unit LCU. The combined circuit switch balancing and load control unit SBLCU, an ammeter for measuring the capacitor voltages V1, V2, a circuit switch S C , complementary circuit switch S C', the ammeter A and the first current influencing component I1 form or include a combined circuit switch balancing and load control circuit 17.

[0073] also, Fig.10 A device 1j is shown having a combined circuit switch balancing load and discharge control unit SBLDCU combining the functionality of a combined circuit switch balancing and load control unit SBLCU and a discharge control unit DCU. Thus, the combined circuit switch balancing load and discharge control circuit 18 comprises the elements of the combined circuit switch balancing and load control circuit 17 and a third current influencing member I3.

[0074] Fig.11 An apparatus 1k having a circuit breaker 20 is shown. The circuit breaker 20 comprises a first circuit breaker input terminal TCBI1 for connecting the positive pole + of a direct current power supply network DC and a second circuit breaker input terminal TCBI2 for connecting the negative pole - of the direct current power supply network DC. In addition, the circuit breaker 20 comprises a first circuit breaker output terminal TCBO1 for connecting a first external tap of two series capacitors C1 and C2 and a second circuit breaker output terminal TCBO2 for connecting a second external tap of the two series capacitors C1 and C2. In addition, the circuit breaker 20 comprises a first circuit breaker current path connecting the first circuit breaker input terminal TCBI1 and the first circuit breaker output terminal TCBO1 and a second circuit breaker current path connecting the second circuit breaker input terminal TCBI2 and the second circuit breaker output terminal TCBO2. In detail, the first circuit breaker current path is part of the first power line 2, and the second circuit breaker current path is part of the second power line 3. Finally, the circuit breaker 20 comprises an optional third circuit breaker output terminal TCBO3 for connecting a center tap of the two series capacitors C1 , C2 or ground GND.

[0075] Typically, the circuit breaker 20 may include Figures 1 to 10 One or more of the functions or circuits of each of the devices 1a..1j shown, provided that the circuit breaker comprises a circuit breaker S C :

[0076] -Therefore, based on Figure 1 The circuit breaker 20 may include a switch control circuit 10a and a load control circuit 11a, a switch control circuit 10a and a balance control circuit 12a, or a switch control circuit 10a, a load control circuit 11a, and a balance control circuit 12a.

[0077] -based on Figure 2 The circuit breaker 20 may include a switch control circuit 10 (eg, embodied as a Figure 1The switch control circuit 10a) and the load control circuit 11b, the switch control circuit 10 and the discharge control circuit 13a, the switch control circuit 10 and the load control circuit 11b and the discharge control circuit 13a, the switch control circuit 10 and the combined balancing and discharge control circuit 14a, or the switch control circuit 10 and the load control circuit 11b and the combined balancing and discharge control circuit 14a.

[0078] -based on Figure 3 The circuit breaker 20 may include a switch control circuit 10 (eg, embodied as a Figure 1 The switch control circuit 10a) and the load control circuit 11 (for example, embodied as similar to Figure 1 The load control circuit 11a or Figure 2 load control circuit 11b) and combined balancing and discharge control circuit 14b.

[0079] -based on Figure 4 The circuit breaker 20 may include a combination circuit switch and load control circuit 15 or a combination circuit switch and load control circuit 15 and a balance control circuit 12 (eg, embodied as a circuit similar to Figure 1 A combination of a balance control circuit 12a).

[0080] -based on Figure 5 The circuit breaker 20 may include a switch control circuit 10 (eg, embodied as a Figure 1 In particular, the first sub-current influencing component IS1 and the second sub-current influencing component IS2 can each be implemented similar to Figure 6 The buck converter depicted in

[0081] -.based on Figure 7 The circuit breaker 20 may include a switch control circuit 10 (eg, embodied as a Figure 1 The switch control circuit 10a), the combined balancing and load control circuit 16 (for example, embodied as a similar Figure 5 and 6 The discharge control circuit 13c can also be implemented as Figure 8 shown.

[0082] -based on Fig. 9 The circuit breaker 20 may include the combined circuit switch balancing and load control circuit 17 or a combination of the combined circuit switch balancing and load control circuit 17 and the discharge control circuit 13 (eg, embodied similarly to the discharge control circuits 13a . . 13c ).

[0083] -based on Fig.10The circuit breaker 20 may ultimately include a combined circuit switch balancing load and a discharge control circuit 18 .

[0084] Similar considerations can be made for the pre-charging device 21, which Fig.12 2 is shown in combination with the circuit breaker 20. The pre-charging device 21 includes a first pre-charger input terminal TPDI1 for connecting the positive pole + of the DC power supply network DC and a second pre-charger input terminal TPDI2 for connecting the negative pole - of the DC power supply network DC. In addition, the pre-charging device 21 includes a first pre-charger output terminal TPDO1 for connecting the first external tap of the two series capacitors C1 and C2 and a second pre-charger output terminal TPDO2 for connecting the second external tap of the two series capacitors C1 and C2. In addition, the pre-charging device 21 includes a first pre-charger current path connecting the first pre-charger input terminal TPDI1 and the first pre-charger output terminal TPDO1 and a second pre-charger current path connecting the second pre-charger input terminal TPDI2 and the second pre-charger output terminal TPDO2. In detail, the first pre-charger current path is part of the first power line 2, and the second pre-charger current path is part of the second power line 3. Finally, the pre-charging device 21 includes an optional third pre-charger output terminal TPDO3 for connecting the middle tap of the two series capacitors C1 and C2 or the ground GND.

[0085] like Fig.12 As shown, capacitors C1, C2 do not have to be directly connected to circuit breaker output terminals TCBO1, TCBO2 of circuit breaker 20, but may also be indirectly connected thereto via pre-charging device 21. The same is true for pre-charging device 21, since the positions of circuit breaker 20 and pre-charging device 21 may vary.

[0086] Typically, the pre-charging device 21 may include Figures 1 to 10 One or more of the functions or circuits of each of the devices 1a..1j shown:

[0087] -Therefore, based on Figure 1 The pre-charging device 21 may include a load control circuit 11a, a balance control circuit 12a, or a combination of the load control circuit 11a and the balance control circuit 12a.

[0088] -based on Figure 2 The pre-charging device 21 may include a load control circuit 11b, a balance control circuit 12a or a discharge control circuit 13a or any combination thereof.

[0089] -based on Figure 3 The pre-charging device 21 may include a load control circuit 11 (for example, embodied as a Figure 1 The load control circuit 11a or Figure 2 load control circuit 11b) or combined balancing and discharge control circuit 14b or a combination thereof.

[0090] -based on Figure 5 The pre-charging device 21 may include a combined balancing and load control circuit 16a. In particular, the first sub-current influencing component IS1 and the second sub-current influencing component IS2 may each be implemented similarly to Figure 6 The buck converter depicted in

[0091] -.based on Figure 7 The pre-charging device 21 may include a combined balancing and load control circuit 16 (e.g., embodied as a similar Figure 5 and 6 The discharge control circuit 13c may also be implemented as a combination of the balancing and load control circuits 16a and 16b) or the discharge control circuit 13b or a combination thereof. Figure 8 shown).

[0092] Based on the above considerations, Figures 1 to 10 The functions or circuits of each of the devices 1a..1j shown may be integrated in the circuit breaker 20 or may be divided between the circuit breaker 20 and the pre-charging device 21. Functions or circuits that are neither part of the circuit breaker 20 nor part of the pre-charging device 21 may be integrated in one or more further devices.

[0093] like Fig.12 As depicted in FIG. 1 , there may be one or more communication channels 22 between the circuit breaker 20 and the pre-charging device 21 (or the other device), and the one or more communication channels may be embodied as wired or wireless communication channels 22 (see FIG. 1 ). Figures 1 to 10 ).

[0094] In all examples, depending on the specific situation, there may be a third capacitor C3, and of course there may also be a load L D In addition, in all examples, the first switch S1, S1', the second switch S2, S2', the circuit switch S C , S C ' and / or discharge switch S D It may be embodied as an electronic switch (eg, a transistor) or an electromechanical switch (eg, a relay).

[0095] Fig.13 A solid-state circuit breaker / switch is shown which includes two IGBTs (Insulated Gate Bipolar Transistors) 32 and 33 and an overvoltage protection device 34. Inductor 31 represents line inductance. Fig.13Also shown is a pre-charging unit represented by an electronic smoothing inductor ESI, which comprises an inductor 35, a capacitor 38 and an active rectifier having two diodes 36 and 40 and two semiconductor switches 37 and 39. The ESI is an active rectifier and acts as a constant current source. Resistor 41 represents the line resistance on the load side. In addition, capacitor 42 represents the load capacitance to be charged. The ESI controls the voltage across it (from 35 to 40) and thus controls the charging current.

[0096] Fig.14 A solid-state circuit breaker / switch is shown, which includes two IGBTs 51 and 52 and an overvoltage protection device 53. It also shows a pre-charging unit, which includes an ohmic resistor 55 and a mechanical switch 54 such as a contactor. Pre-charging starts by closing the switch 54 to create a high-ohmic path via the resistor 55 between the bus side and the load side. The capacitor is charged with a small current. In order to avoid thermal overloading of the resistor 55 due to the charging current, a PTC resistor can be used. It reduces the charging current when heated. After the capacitor is charged to the bus voltage, the semiconductor elements 51 and 52 are turned on and the mechanical switch 54 is disconnected.

[0097] Fig.15 A solid-state circuit breaker / switch is shown, which consists of two IGBTs 61 and 62 and an overvoltage protection device 63. It also shows a pre-charging unit, which is implemented as a buck converter, which includes diodes 64, 67, a transistor 65 (here a MOSFET transistor) and an inductor 66. The basic operation of the buck converter is as follows: First, the transistor 65 is turned on, and thus the current flows to the external capacitor ( Fig.15 66), thereby charging it. Since the voltage across the capacitor cannot rise immediately and since the inductor 66 limits the charging current, the voltage across the capacitor during the switching cycle is not the full bus voltage of the power supply. In the second phase, transistor 65 is turned off. Since the current in inductor 66 cannot change suddenly, inductor 66 produces a voltage across it. When transistor 65 is turned off, this voltage is allowed to charge the capacitor and supply power to the load through diode 67. The buck converter is controlled in a manner that acts as a constant current source. The circuit breaker switches 61 and 62 (here IGBTs) are inactive (turned off) during pre-charging. After the capacitor is charged to the bus voltage, semiconductor switches 61 and 62 are turned on, and the pre-charging switch 65 is turned off.

[0098] Fig.16A solid-state circuit breaker / switch is shown, which includes two IGBTs 71 and 72 and an overvoltage protection device 73. It also shows a pre-charging unit, which is implemented as a buck converter including a diode 74, an inductor 75, a mechanical switch 74 and an IGBT 72. Fig.15 The difference is that the buck converter is incorporated in the circuit breaker, which means that the circuit breaker switch 71 is used as the switching element of the buck converter ( Fig.15 The advantage here is that the already existing switching element 71 acts as a circuit breaker switch during normal operation (protection) and as a constant current source during pre-charging. The mechanical switch 76 is closed in normal operation (protection) to minimize power losses (thus bypassing the inductor 75).

[0099] Furthermore, it should be noted that the invention is not limited to the embodiments disclosed above, but combinations of different variants are possible. In practice, the apparatus 1a..1l, the circuit breaker 20 or the pre-charging device 21 may have more or fewer parts than shown in the drawings. Furthermore, the present specification may include the subject matter of further independent inventions.

[0100] It should also be noted that the term "comprising" does not exclude other elements, and the use of the article "a" or "an" does not exclude a plurality. Moreover, elements described in connection with different embodiments may be combined. It should also be noted that the reference signs in the claims should not be interpreted as limiting the scope of the claims.

[0101] Reference numerals list

[0102] 1a..1l Equipment

[0103] 2.3 Power cord

[0104] 4, 4a, 4b Switchable high-ohmic path

[0105] 5, 5a, 5b Switchable low ohmic path

[0106] 10, 10a Circuit switch control circuit / main switch control circuit

[0107] 11, 11a, 11b Load control circuit

[0108] 12.12a Balance control circuit

[0109] 13. 13a..13c Discharge control circuit

[0110] 14a, 14b Combined balancing and discharge control circuit

[0111] 15 Combination circuit switch and load control circuit

[0112] 16, 16a, 16b Combined balancing and load control circuit

[0113] 17 Combination Circuit Switch Balance and Load Control Circuit

[0114] 18 Combination circuit switch balance load and discharge control circuit

[0115] 20 Circuit Breaker

[0116] 21 Pre-charging device

[0117] 22 Communication Channels

[0118] SCU Circuit Switching Control Unit

[0119] LCU Load Control Unit

[0120] BCU Balance Control Unit

[0121] DCU Discharge Control Unit

[0122] BDCU Combined Balancing and Discharge Control Unit

[0123] SLCU Combined Circuit Switch and Load Control Unit

[0124] BLCU Combined Balancing and Load Control Unit

[0125] SBLCU Combined Circuit Switch Balancing and Load Control Unit

[0126] SBLDCU Combined Circuit Switch Balanced Load and Discharge Control Unit

[0127] DC power supply network

[0128] - Negative electrode

[0129] + Positive

[0130] GND Ground

[0131] S1, S1' First switch

[0132] S2, S2' Second switch

[0133] S C , S C ' Circuit switch

[0134] S D Discharge switch

[0135] I1..I3 Current affecting components

[0136] IS1, IS2 sub-current influencing components

[0137] C1..C3 capacitors

[0138] R L Load resistor

[0139] R D Discharge resistor

[0140] A Amperemeter

[0141] V1, V2 Voltage of each of the two series capacitors / ammeters

[0142] V T Total voltage of two capacitors / ammeters in series

[0143] D1, D2 diodes

[0144] L1, L2 inductors

[0145] LD Load

[0146] M Manual button

[0147] TCBI1, TCBI2 circuit breaker input terminals

[0148] TCBO1..TCBO3 circuit breaker output terminals

[0149] TPDI1, TPDI2 pre-charger input terminals

[0150] TPDO1..TPDO3 pre-charger output terminals

[0151] 31, 35, 66, 75 inductors

[0152] 32, 33, 51, 52, 61, 62, 71, 72 Insulated Gate Bipolar Transistors

[0153] 34, 53, 63, 73 Overvoltage protector

[0154] 36, 40, 64, 67, 74 diodes

[0155] 37, 39 Semiconductor switch

[0156] 38, 42 Capacitor

[0157] 54, 76 Mechanical switch

[0158] 41, 55 resistors

[0159] 65 Transistor

Claims

1. A device (1a..1l), comprising - a direct current power supply network (DC) having a positive pole (+) and a negative pole (-), - two capacitors (C1, C2) connected in series, wherein a first outer tap is connected to the positive pole (+) via a first power supply line (2), a second outer tap is connected to the negative pole (-) via a second power supply line (3), and a middle tap is connected to ground (GND), -Circuit switch (S C ), the circuit switch being arranged in at least one of the first and the second power supply lines (2, 3), - a circuit breaker control unit (SCU) designed to disconnect the circuit breaker (S C ), a switchable high-ohmic path (4) in at least one of the first and second power supply lines (2, 3), the switchable high-ohmic path bypassing a) a switchable low-ohmic path (5) in the at least one of the first and second power supply lines (2, 3) or b) the circuit switch (S C ),as well as - a load control unit (LCU) designed to measure the total voltage (V T ), and if the measured total voltage (V T ) is lower than the first threshold voltage, then in case a) the high-ohmic path (4) is switched on and the low-ohmic path (5) is switched off, or in case b) the high-ohmic path (4) is switched on and the circuit switch (S) is switched off. C ), and if the measured total voltage (V T ) is equal to or higher than the first threshold voltage or higher than a second higher threshold voltage, the low-ohmic path (5) is switched on in case a) or the circuit switch (S) is switched on in case b). C ), wherein the first threshold voltage and, when present, the second higher threshold voltage are arranged to be lower than the voltage of the direct current power supply network (DC) between its positive (+) and negative (-) poles, It is characterized in that The device (1a..1l) further comprises a balancing control unit (BCU) designed to measure the capacitor voltage (V1, V2) of each of the two series capacitors (C1, C2), detect an imbalance of these capacitor voltages (V1, V2) and individually control the current through the two series capacitors (C1, C2) by using a first current influencing member (I1), wherein if the first capacitor voltage (V1) of the first capacitor (C1) of the two series capacitors (C1, C2) is lower than the second capacitor voltage (V2) of the second capacitor (C2) of the two series capacitors (C1, C2), the current through the first capacitor (C1) is higher than the current through the second capacitor (C2), and vice versa.

2. A circuit breaker (20), comprising - a first circuit breaker input terminal (TCBI1) and a second circuit breaker input terminal (TCBI2), the first circuit breaker input terminal being used to connect to the positive pole (+) of a direct current power supply network (DC), the second circuit breaker input terminal being used to connect to the negative pole (-) of the direct current power supply network (DC), - a first circuit breaker output terminal (TCBO1) and a second circuit breaker output terminal (TCBO2), wherein the first circuit breaker output terminal is used to connect a first external tap of two series capacitors (C1, C2), and the second circuit breaker output terminal is used to connect a second external tap of the two series capacitors (C1, C2), - a first circuit breaker current path connecting the first circuit breaker input terminal (TCBI1) and the first circuit breaker output terminal (TCBO1) and a second circuit breaker current path connecting the second circuit breaker input terminal (TCBI2) and the second circuit breaker output terminal (TCBO2), -Circuit switch (S C ), the circuit breaker being arranged in at least one of the first and the second circuit breaker current paths, - a circuit breaker control unit (SCU) designed to disconnect the circuit breaker (S C ), a switchable high-ohmic path (4) in at least one of the first and the second circuit breaker current paths, the switchable high-ohmic path bypassing a) a switchable low-ohmic path (5) in the at least one of the first and the second circuit breaker current paths or b) the circuit breaker (S C ),as well as - a load control unit (LCU) designed to measure the total voltage (V T ), and if the measured total voltage (V T ) is lower than the first threshold voltage, then in case a) the high-ohmic path (4) is switched on and the low-ohmic path (5) is switched off, or in case b) the high-ohmic path (4) is switched on and the circuit switch (S) is switched off. C ), and if the measured total voltage (V T ) is equal to or higher than the first threshold voltage or higher than a second higher threshold voltage, the low-ohmic path (5) is switched on in case a) or the circuit switch (S) is switched on in case b). C ), wherein the first threshold voltage and, when present, the second higher threshold voltage are arranged to be lower than a nominal voltage which can be applied to the first circuit breaker input terminal (TCBI1) and the second circuit breaker input terminal (TCBI2), It is characterized in that The circuit breaker (20) further comprises a third circuit breaker output terminal (TCBO3) for connecting a center tap of the two series capacitors (C1, C2) and a balancing control unit (BCU), the balancing control unit being designed to measure a first voltage (V1) between the first circuit breaker output terminal (TCBO1) and the third circuit breaker output terminal (TCBO3) and a second voltage (V2) between the third circuit breaker output terminal (TCBO3) and the second circuit breaker output terminal (TCBO2), detect an unbalance between the first and second voltages (V1, V2) and individually control the current through the first circuit breaker output terminal (TCBO1) and the second circuit breaker output terminal (TCBO2) by using a first current influencing member (I1), wherein if the first voltage (V1) is lower than the second voltage (V2), the current through the first circuit breaker output terminal (TCBO1) is higher than the current through the second circuit breaker output terminal (TCBO2), and vice versa.

3. The circuit breaker (20) according to claim 2, characterized in that: The first current influencing component (I1) includes a first sub-current influencing component (IS1) switched between the first circuit breaker output terminal (TCBO1) and the third circuit breaker output terminal (TCBO3) and a second sub-current influencing component (IS2) switched between the third circuit breaker output terminal (TCBO3) and the second circuit breaker output terminal (TCBO2).

4. The circuit breaker (20) according to claim 2 or 3, further comprising a discharge control unit (DCU) designed to control a discharge current between the first circuit breaker output terminal (TCBO1) and the second circuit breaker output terminal (TCBO2) by means of a controlled current through the first current influencing member (I1) in the following situations, - Case a): When the circuit switch (S C ) is disconnected, when the high ohmic path (4) and the low ohmic path (5) are disconnected, when the circuit switch (S C ) is zero or when the current through the high-ohmic path (4) and the low-ohmic path (5) is zero, and - Case b): When the circuit switch (S C ) is disconnected and the high-ohmic path (4) is closed, or when the circuit switch (S C ) and the current in the high-ohmic path (4) is zero.

5. The circuit breaker (20) according to claim 2, characterized in that: The first current influencing member (I1) comprises a first sub-current influencing member (IS1) and a second sub-current influencing member (IS2), wherein the first sub-current influencing member (IS1) is arranged in a first switchable high-ohmic path (4a) in the first circuit breaker current path, the first switchable high-ohmic path bypassing a) a first switchable low-ohmic path (5a) in the first circuit breaker current path or b) the circuit breaker (S) in the first circuit breaker current path. C ), and wherein the second sub-current influencing member (IS2) is arranged in a second switchable high-ohmic path (4b) in the second circuit-breaker current path, the second switchable high-ohmic path bypassing in case a) a) a second switchable low-ohmic path (5b) in the second circuit-breaker current path or in case b) a complementary circuit switch (S) in the second circuit-breaker current path. C ').

6. The circuit breaker (20) according to claim 5, further comprising a discharge control unit (DCU) designed to control a discharge current between the first circuit breaker output terminal (TCBO1) and the second circuit breaker output terminal (TCBO2) by means of a controlled current through a third current influencing member switched between the first circuit breaker output terminal (TCBO1) and the second circuit breaker output terminal (TCBO2), in the following cases, - Case a): When the circuit switch (S C ) is disconnected, when the high ohmic path (4) and the low ohmic path (5) are disconnected, when the circuit switch (S C ) is zero or when the current through the high-ohmic path (4) and the low-ohmic path (5) is zero, and - Case b): When the circuit switch (S C ) is disconnected and the high-ohmic path (4) is closed, or when the circuit switch (S C ) and the current in the high-ohmic path (4) is zero.

7. A pre-charging device (21), comprising - a first pre-charger input terminal (TPDI1) and a second pre-charger input terminal (TPDI2), wherein the first pre-charger input terminal is used to connect to the positive pole (+) of a direct current power supply network (DC), and the second pre-charger input terminal is used to connect to the negative pole (-) of the direct current power supply network (DC), a first pre-charger output terminal (TPDO1) and a second pre-charger output terminal (TPDO2), wherein the first pre-charger output terminal is used to connect a first external tap of two capacitors connected in series (C1, C2), and the second pre-charger output terminal is used to connect a second external tap of the two capacitors connected in series (C1, C2), - a first pre-charger current path connecting the first pre-charger input terminal (TPDI1) and the first pre-charger output terminal (TPDO1) and a second pre-charger current path connecting the second pre-charger input terminal (TPDI2) and the second pre-charger output terminal (TPDO2), and - a switchable high-ohmic path (4) in at least one of the first and the second pre-charger current paths, the switchable high-ohmic path bypassing the switchable low-ohmic path (5) in the at least one of the first and the second pre-charger current paths and a load control unit (LCU) designed to measure a total voltage (V) between the first pre-charger output terminal (TPDO1) and the second pre-charger output terminal (TPDO2) T ), and if the measured total voltage (V T ) is lower than a first threshold voltage, the high ohmic path (4) is turned on and the low ohmic path (5) is turned off, and if the measured total voltage (V T ) is equal to or higher than the first threshold voltage or higher than a second higher threshold voltage, the low ohmic path (5) is turned on, wherein the first threshold voltage and the second higher threshold voltage, when present, are set below a nominal voltage that can be applied to the first pre-charger input terminal (TPDI1) and the second pre-charger input terminal (TPDI2), It is characterized in that The pre-charging device (21) further comprises a third pre-charger output terminal (TPDO3), the third pre-charger output terminal being used to connect the middle tap of the two series capacitors (C1, C2) and a balancing control unit (BCU), the balancing control unit being designed to measure a first voltage (V1) between the first pre-charger output terminal (TPDO1) and the third pre-charger output terminal (TPDO3) and a second voltage (V2) between the third pre-charger output terminal (TPDO3) and the second pre-charger output terminal (TPDO2), detect an imbalance between the first and second voltages (V1, V2) and individually control the current through the first pre-charger output terminal (TPDO1) and the second pre-charger output terminal (TPDO2) by using a first current influencing component (I1), wherein if the first voltage (V1) is lower than the second voltage (V2), the current through the first pre-charger output terminal (TPDO1) is higher than the current through the second pre-charger output terminal (TPDO2), and vice versa.

8. The pre-charging device (21) according to claim 7, characterized in that: The first current influencing component (I1) includes a first sub-current influencing component (IS1) switched between the first pre-charger output terminal (TPDO1) and the third pre-charger output terminal (TPDO3) and a second sub-current influencing component (IS2) switched between the third pre-charger output terminal (TPDO3) and the second pre-charger output terminal (TPDO2).

9. The pre-charging device (21) according to claim 7 or 8, further comprising a discharge control unit (DCU) designed to control a discharge current between the first pre-charger output terminal (TPDO1) and the second pre-charger output terminal (TPDO2) by means of a controlled current through the first current influencing member (I1) in the following cases, - When the high-ohmic path (4) and the low-ohmic path (5) are disconnected, or when the current through the high-ohmic path (4) and the low-ohmic path (5) is zero.

10. The pre-charging device (21) according to claim 7, characterized in that: The first current influencing component (I1) includes a first sub-current influencing component (IS1) and a second sub-current influencing component (IS2), wherein the first sub-current influencing component (IS1) is arranged in a first switchable high-ohmic path (4a) in the first pre-charger current path, the first switchable high-ohmic path bypasses the first switchable low-ohmic path (5a) in the first pre-charger current path, and wherein the second sub-current influencing component (IS2) is arranged in a second switchable high-ohmic path (4b) in the second pre-charger current path, the second switchable high-ohmic path bypasses the second switchable low-ohmic path (5b) in the second pre-charger current path.

11. The pre-charging device (21) according to claim 10, further comprising a discharge control unit (DCU) designed to control a discharge current between the first pre-charger output terminal (TPDO1) and the second pre-charger output terminal (TPDO2) by means of a controlled current of a third current influencing member switched between the first pre-charger output terminal (TPDO1) and the second pre-charger output terminal (TPDO2) in the following case, - When the high-ohmic path (4) and the low-ohmic path (5) are disconnected, or when the current through the high-ohmic path (4) and the low-ohmic path (5) is zero.

Images