Power distribution

Abstract

Power distributor (8) with a housing (14) in which a feed-in connection (36) and several supply connections (20) are provided, and in which a DC circuit (38) is arranged which is electrically connected to the feed-in connection (36) and each of the supply connections (20).

Description

[0001] The invention relates to a power distributor and a motor vehicle with a power distributor.

[0002] Motor vehicles, such as trains, have a variety of different electrical auxiliary systems that do not directly contribute to propulsion but, for example, provide safety and / or comfort features. Examples of such auxiliary systems include lighting, heating, or pneumatic or hydraulic systems, which in turn can perform other functions, such as opening or closing doors. To transmit the electrical energy required to operate each auxiliary system, cables or similar components are typically used, which are connected to the vehicle's electrical system at a suitable point via a current transformer, such as a DC / DC converter. The DC / DC converter, for example, adjusts the voltage and / or current supplied to the respective auxiliary system.

[0003] If the auxiliary unit or the line leading to it malfunctions, a comparatively high electrical current may be carried through it, especially in the event of a short circuit. This can result in significant heating, which may damage the auxiliary unit, the line leading to it, and / or adjacent components. Furthermore, a fire may develop, potentially causing further damage to the train. To prevent such an event, fuses are typically installed. These are usually located directly at the auxiliary unit, which simplifies installation. However, if a fuse has blown, which can occur due to a temporary malfunction and / or specific environmental conditions, it must be replaced to check and, if necessary, restore the functionality of the auxiliary unit.This requires, for example, the removal of interior paneling or similar components, making it relatively complicated. Knowledge of the exact location of the safety device is also necessary, which is why such work can only be carried out by trained personnel.

[0004] In building services engineering, electrical distribution boards are commonly used, featuring a power supply connection and multiple supply connections. The power supply connection is electrically connected to a supply network during installation, carrying a three-phase alternating current. The distribution board contains several DIN rails on which circuit breakers and / or miniature circuit breakers (MCBs) can be mounted. Typically, the circuit breakers / MCBs assigned to a particular DIN rail are electrically connected to one of the phases of the power supply connection via a busbar or similar connection. Several electrical cables run into the distribution board, each dedicated to a different branch circuit of the building. Each cable is connected to a circuit breaker / MCB, thus protecting both the circuit breaker and its associated branch circuit.

[0005] The invention is based on the objective of providing a particularly suitable power distributor and a particularly suitable motor vehicle, wherein safety is increased in particular, and manufacturing costs are expediently reduced.

[0006] With regard to the power distributor, this problem is solved according to the invention by the features of claim 1, and with regard to the motor vehicle by the features of claim 14. Advantageous further developments and embodiments are the subject of the respective dependent claims.

[0007] The power distribution unit is suitable and intended for use in building technology. In other words, when installed, the power distribution unit is an integral part of a building. However, it is particularly preferred that the power distribution unit is suitable and intended for use in a motor vehicle. Thus, when installed, the power distribution unit forms an integral part of the motor vehicle, which could be, for example, a ship or boat. Alternatively, the motor vehicle could be an aircraft, such as an airplane. However, it is particularly preferred that the motor vehicle be land-based. For this purpose, the motor vehicle has, in particular, a number of wheels that are driven by a propulsion system. For example, the motor vehicle has a number of steerable wheels by means of which the direction of travel of the motor vehicle can be set.A motor vehicle is, in particular, an agricultural machine, such as a tractor (i.e., an agricultural towing vehicle), a combine harvester, a planting machine, or a fertilizer spreader. Alternatively, a motor vehicle is, in particular, a construction machine, such as an excavator, a front loader, a dump truck, a side tipper, a forklift, or another commercial vehicle, such as a truck or a bus. Alternatively, a motor vehicle could be, for example, a passenger car.

[0008] Preferably, however, the motor vehicle is rail-bound, i.e., a rail vehicle. The rail vehicle is, for example, a locomotive, particularly an electric locomotive, which has a pantograph or similar device for electrical contact with an overhead line. Alternatively, the locomotive is, for example, a hybrid locomotive with an electric motor for propulsion. The locomotive also includes a diesel engine that drives a generator, which in turn supplies power to the electric motor. Preferably, the rail vehicle includes a power car and is thus configured as a train. The rail vehicle is used, for example, in long-distance or regional transport, or is configured as a tram or subway.

[0009] The power distribution unit has a housing containing a power inlet and several supply connections. These connections allow for electrical contact with the components of the power distribution unit located inside the housing. The housing effectively forms the outer boundary of the power distribution unit, thus protecting the remaining parts from environmental influences. Furthermore, this provides touch protection, thereby increasing safety.

[0010] The power distribution unit has a DC circuit located inside the housing. This circuit is electrically connected to the power input and each of the supply terminals. Therefore, the DC circuit can be powered via the power input, which in turn supplies the supply terminals. This allows electrical energy supplied and / or fed into the power input to be routed to the individual supply terminals.

[0011] In its assembled state / during operation, the DC circuit carries a DC voltage and has two different (electrical) poles. Specifically, the voltage between the individual poles, and thus across the DC circuit, is greater than or equal to 12 V, 48 V, or 60 V. Advantageously, the applied voltage is less than 1000 V or 800 V. A DC voltage of 110 V across the DC circuit is particularly preferred, making the power distributor comparatively well-suited for railway applications.

[0012] The power supply connection has, in particular, two plugs or the like, between which the DC voltage is present during assembly, supplied via the DC circuit. This eliminates the need for additional components, thus reducing the manufacturing costs of the power distributor. Alternatively, or more preferably in combination, the supply connections each have two plugs or the like, also supplied with the same DC voltage, in particular the same voltage supplied via the DC circuit. Again, this eliminates the need for additional components, thus reducing the size and manufacturing costs of the power distributor. In summary, the power supply connection and the supply connections are preferably designed as two-pole connections, and the same voltage is always supplied via these connections as is present in the DC circuit.

[0013] Therefore, the power distributor is advantageously suited for a DC voltage application, or at least, during operation, it carries a DC voltage that is present in the DC circuit and supplies power to the supply terminals. This simplifies the electrical wiring in a DC application, particularly in the vehicle where the power distributor is used. The housing protects the electrical contacts, which are responsible for distributing the electrical energy supplied via the input terminal to the supply terminals. This increases safety.

[0014] Preferably, the power supply connection has one or more screw terminals, with each pole expediently having its own screw terminal. For example, the power supply connection thus comprises two screw terminals if a DC voltage is supplied at the power supply connection. This design allows for a relatively robust connection of the power supply connection to a supply line or the like, which is expediently part of the vehicle's electrical system. Furthermore, it is possible to use a supply line with a relatively large cross-section, thus enabling the supply of a relatively high electrical current and / or high electrical energy without overloading.

[0015] For example, the supply connections may be designed differently and feature different methods of securing the associated cable. Alternatively, the supply connections may be identical in construction, allowing the use of standard components. A particularly preferred configuration is for the supply connections to be different, yet always operating on the same principle. This ensures that connecting a cable to the supply connections is always done in the same way. Due to the different designs, however, it is possible to adapt the supply connections to different cables, which differ primarily in cross-section. Thus, for instance, a relatively high electrical current can be carried through a single supply connection, allowing for the use of a cable with a large cross-section.In contrast, one or more supply connections are designed so that only a cable with a reduced cross-section can be connected, thus reducing the maximum electrical current that can be carried through it. This reduces the manufacturing costs of such a cable, and it can be routed with relative flexibility, simplifying installation. The supply connections are preferably designed as push-in terminals or spring-cage terminals. This allows for quick and easy connection of the respective cable without the need for additional tools. This can even be done after the power distribution unit has been installed. Disconnecting the cables remains possible, for example, if the components powered by these cables need to be replaced.

[0016] It is advantageous that at least one of the supply connections is suitable and equipped to carry a rated electrical current of 5 A, 10 A, 15 A, and / or 20 A. In particular, the feed-in connection is suitable, equipped, and designed to carry a rated electrical current of up to 40 A, 50 A, 60 A, 70 A, or 80 A. This allows for the carrying of comparatively high electrical currents without excessively increasing manufacturing costs or size.

[0017] For example, the DC circuit is directly connected to the power supply connection. This reduces manufacturing costs and size. However, it is particularly preferred that the DC circuit is connected to the power supply connection via a switching device. This device is, for example, single-pole, so that at least one pole of the DC circuit can be disconnected from the corresponding pole of the power supply connection. For example, such a switching device is assigned to both poles, so that both poles of the DC circuit can be disconnected from the power supply connection, for example, independently of each other. However, it is particularly preferred that the switching device be double-pole.When the switching device is activated, both poles of the DC circuit are electrically disconnected from the power supply connection, preventing any electrical current from flowing from the power supply connection into the DC circuit. Consequently, no voltage is present at the DC circuit, and the supply connections are also de-energized. This allows for relatively simple maintenance and / or reconfiguration of the power distribution unit and the components it powers.

[0018] The switching device is, for example, manually operable and expediently features an operating device, such as a switch or lever, that extends through the housing. Therefore, manual operation of the switching device from outside the housing is possible. Suitablely, each pole is assigned a lever as an operating device, and the two levers are expediently mechanically coupled. Thus, the switching device can be formed, for example, by means of two separate switches that are mechanically coupled. This makes it possible to manufacture the switching device using existing components, thereby reducing production costs.

[0019] For example, the switching device is designed as or incorporates a semiconductor switch or similar device. This reduces the overall size and enables switching without the formation of an electric arc. However, it is particularly preferred that the switching device be designed to provide galvanic isolation, which increases safety. Advantageously, the switching device incorporates a mechanical switch for this purpose.

[0020] For example, the switching device can only be operated manually. This reduces complexity. However, the switching device is preferably designed as a protective switch. The switching device advantageously conducts the electrical current flowing through it and analyzes it for fault conditions, such as a fault current, an overcurrent, and / or a short-circuit current. A characteristic curve is advantageously used to determine when such a fault condition exists. Alternatively, or in combination with this, the switching device detects the electrical voltage present at the supply connection and / or the DC circuit, and this is used to determine whether a corresponding fault condition exists. This increases safety.Preferably, the circuit breaker includes one or more sensors by means of which the relevant values, in particular the electric current and / or the applied electric voltage, can be measured or at least recorded. This allows for a comparatively accurate determination of whether a fault has actually occurred. Alternatively, this is achieved implicitly, and the circuit breaker includes a locking mechanism by which, in particular, a mechanical switch or the like is held in place. Advantageously, the switching device includes a mechanical switch that is held in place, in particular, by a bimetallic element against a spring force or the like. The bimetallic element is traversed, in particular, by the electric current carried by the switching device. When this current increases, the bimetallic element is heated and deformed, so that the mechanical switch is released and opened due to the spring force.

[0021] For example, each supply connection is directly electrically connected to the DC circuit. In particular, a switching device, preferably designed as a circuit breaker, is present. This allows for monitoring of the electrical current / voltage carried through the power distribution unit, thus ensuring safety. It is also possible to disconnect the power distribution unit from current and / or voltage. However, it is particularly preferred that each supply connection is electrically connected to the DC circuit via a separate semiconductor switch. Preferably, the semiconductor switches are identical in construction or differ only in their rated current. The semiconductor switches are preferably designed as field-effect transistors, in particular as MOSFETs, IGBTs, JFETs, or GTOs. In particular, the semiconductor switches are therefore power semiconductor switches.For example, the respective semiconductor switch is configured as a two-pole switch. However, it is particularly preferred that each semiconductor switch is only single-pole, thus reducing manufacturing costs. In this configuration, for example, two semiconductor switches are provided per supply terminal, assigned to the different poles of the DC circuit. However, it is particularly preferred that only a single such semiconductor switch is assigned to each supply terminal, thus reducing manufacturing costs. If the respective semiconductor switch is electrically non-conductive, the electrical potential of one of the poles of the DC circuit remains present at the assigned supply terminal, but not the electrical voltage carried by the DC circuit. Therefore, a component connected to the supply terminal is no longer energized. This allows for reconfiguration or replacement of the component.However, the operation of components / loads connected to the other supply connections remains possible, increasing convenience and functionality / availability. Furthermore, the semiconductor switches reduce the overall size and simplify installation. Arc-free switching is also enabled.

[0022] For example, each supply terminal is assigned only the corresponding semiconductor switch, which can interrupt the flow of electrical current from the DC circuit to the supply terminal. Preferably, a fuse is connected in series with each semiconductor switch. Thus, each supply terminal is electrically connected to the DC circuit via the series connection of the assigned semiconductor switch and the fuse. The fuse further increases safety. It is also possible, for example, to use the semiconductor switch only for the predetermined / proper operation of the component connected to the supply terminal, without providing any safety functions. Therefore, controlling the semiconductor switches is simplified.The electrical protection is provided by the respective fuse, thus increasing safety. In particular, when the fuse trips, a kind of galvanic isolation occurs, so that the supply connection is at least partially galvanically isolated from the DC circuit.

[0023] For example, each pole of the respective supply terminal is assigned a corresponding fuse, or, more preferably, only a single such fuse is present. This reduces manufacturing costs while still providing a comparatively high level of safety. For example, the fuse is arranged between the semiconductor switch and the DC circuit. More preferably, however, it is arranged between the semiconductor switch and the supply terminal. This makes it possible to operate the semiconductor switch in a non-conductive manner, allowing the fuse to be replaced without voltage. More preferably, the fuse is designed as a surface-mount component, in particular as a so-called SMD. This eliminates the need for an additional assembly step, thus reducing manufacturing costs. The required package size is also reduced.

[0024] It is particularly advantageous if the fuse is present and the associated semiconductor switch is also present. Alternatively, the semiconductor switch is not present, so that each supply connection is electrically connected to the DC circuit via its respective fuse. This still provides a high level of safety, even though reversible and / or intentional interruption of the electrical current is not possible.

[0025] It is particularly preferred that each supply connection is assigned a surge protector. Advantageously, the series connection of each fuse and the respective semiconductor switch is bypassed by the respective surge protector. If only the semiconductor switch or only the fuse is present, it is particularly preferred that each be bypassed by the corresponding surge protector. The surge protector is, for example, designed as a two-pole device, or, more preferably, as a single-pole device, which reduces manufacturing costs. If a voltage spike or similar event occurs during operation, it is intercepted by the surge protector, so that the semiconductor switch / fuse is not destroyed by a relatively short-term event or at least by a surge.Preferably, the overvoltage protection is designed to become electrically conductive before the semiconductor switch / fuse is destroyed. A switching device is particularly preferred, and this is expediently designed as a circuit breaker. If an overvoltage is present for a relatively long period, this device is triggered, thus disconnecting the DC circuit from the power supply connection and preventing damage, even if the overvoltage protection is present. Advantageously, a varistor is used as the overvoltage protection device, which reduces complexity and manufacturing costs.

[0026] For example, each semiconductor switch is assigned a control terminal, which is also integrated into the housing. The operation of the respective semiconductor switch is controlled via this terminal, making it either electrically conductive or non-conductive. Specifically, an electrical voltage of less than 12 V, or essentially 5 V, is applied to the control terminal, thus changing the switching state of the semiconductor switch. This relatively low voltage reduces the required operating voltage. It also allows for flexible actuation of the semiconductor switches, ideally depending on current requirements. Actuation can also be performed remotely from the power distribution unit, for example, via a higher-level control system, if a suitable line is connected to the respective control terminal. This further increases flexibility.

[0027] Preferably, the power distributor includes a control unit. This control unit advantageously actuates the semiconductor switches. For example, each semiconductor switch may be assigned its own corresponding control unit. However, preferably only a single control unit is present, which actuates all semiconductor switches. This reduces manufacturing costs and space requirements. For example, the control unit may also include a driver circuit for the semiconductor switches, or a driver circuit for the semiconductor switches may be provided, which is suitably actuated by the control unit. The control unit may be implemented using discrete components, particularly electronic components. Alternatively, the control unit may comprise an application-specific integrated circuit (ASIC).The control unit preferably included a microprocessor, which was advantageously designed to be programmable. This makes it possible to adapt the power distributor to different applications without having to replace individual components. This reduces manufacturing costs and increases flexibility.

[0028] The control unit is supplied with electrical energy, for example, via the power supply connection or the DC circuit. For this purpose, the control unit is electrically connected to the power supply connection / DC circuit via a DC / DC converter. This eliminates the need for additional connections and wiring, thus simplifying the installation of the power distribution unit. Alternatively, an auxiliary connection or similar is integrated into the housing to supply the control unit with electrical energy. This connection provides a low voltage, specifically a DC voltage of less than 60 volts and preferably less than or equal to 12 V or 5 V. This allows the control unit to operate even when no voltage is present at the power supply connection or DC circuit, thus increasing its flexibility.

[0029] Preferably, each supply terminal is assigned a current sensor by means of which the electric current flowing through the respective supply terminal can be measured. During operation, measurement data is expediently provided by means of each current sensor, which, for example, directly corresponds to the measured electric current, or from which the electric current flowing to the respective supply terminal can at least be determined. Preferably, the current sensors are identical in construction, which reduces manufacturing costs. The respective current sensor is, in particular, a shunt and suitably includes a measuring resistor. Preferably, an operational amplifier or the like is also present by means of which the electric voltage across the respective measuring resistor can be measured. Based on this and the known value of the electrical resistance of the measuring resistor, it is possible to determine the electric current flowing through it.Alternatively, each current sensor includes a Hall sensor.

[0030] Each current sensor is preferably connected to the common or individual control unit via a signal connection, so that the control unit can read the current sensor's measurement data. The control unit then actuates the respective semiconductor switch based on the measurement data acquired by the associated current sensor. In summary, each supply connection is thus assigned its respective current sensor, which is connected to the control unit via a signal connection. The control unit then actuates the associated semiconductor switch based on the measurement data acquired by the respective current sensor.Thus, each semiconductor switch, in conjunction with the respective current sensor and control unit, acts like a protective switch, so that when a certain electric current occurs, for example an overcurrent or short-circuit current, the supply connection is switched off, which increases safety.

[0031] For example, the control unit switches the respective semiconductor switch to the non-conductive state when the current detected by the current sensor exceeds a fixed threshold. This reduces complexity and therefore increases robustness. The threshold can be the same for all supply connections or, expediently, different. Preferably, however, a characteristic curve is used, according to which each semiconductor switch is actuated, and this curve is expediently stored in the control unit. Using this characteristic curve, it is possible to specify the duration for which an overcurrent—that is, an electric current greater than the rated current—can be carried before the semiconductor switch is switched to the non-conductive state. This duration varies for different current intensities.In this case, it is particularly possible to mimic the behavior of a thermal and / or magnetic circuit breaker. Due to its characteristic curve, it is possible to conduct a short-term overcurrent without compromising safety.

[0032] For example, the same characteristic curve is used for all semiconductor switches. However, it is particularly preferred that this curve differs for the various supply connections, thus increasing flexibility. In this case, the characteristic curve used for each semiconductor switch depends on the component connected to and energized by the associated supply connection. For example, the characteristic curve(s) may be fixed. However, it is particularly preferred that they are modifiable. For example, it is possible to select one of several characteristic curves. Selection is achieved, for example, by setting / positioning a jumper or adjusting a coding switch, which then allows for the adjustment. However, it is particularly preferred that the characteristic curve can be modified by programming.This allows for relatively flexible shaping and adjustment of the characteristic curve, which increases safety while ensuring that the semiconductor switch is not mistakenly or unintentionally put into the non-conductive state. This, in turn, increases availability.

[0033] For example, the control unit is already pre-configured when the power distributor is used. In particular, modifying the control unit is not possible. Reading the control unit's status is also not possible. Alternatively, the power distributor can advantageously include a communication interface that is connected to the control unit via signal processing. This makes it possible to query data from the control unit, such as states and / or events, or, more conveniently, to transmit control commands to the control unit, which, for example, actuate any semiconductor switches. Alternatively, or in combination with this, the communication interface can be used to program the control unit, allowing, for example, the modification of its characteristic curves. This increases flexibility. For example, the communication interface is located inside the housing.This means that opening the housing is necessary to communicate with the control unit, thus increasing safety. However, it is particularly advantageous to integrate the communication interface into the housing. This eliminates the need to open the housing, thereby increasing convenience. Furthermore, it is possible, for example, to exchange information with the control unit via the communication interface during operation of the power distributor, such as querying the states of the semiconductor switches or measurement data from any current sensors. It is also possible, for example, to transmit control commands to the control unit, which then switch one of the semiconductor switches to an electrically conductive or non-conductive state. In particular, the arrangement of the communication interface, which is connected to the control unit via signal technology, is independent of whether the current sensor(s) are present.

[0034] For example, the communication interface is suitable, designed, and configured for wireless communication. This might involve adhering to a specific standard, such as WLAN, mobile communication, or Bluetooth. However, a wired communication interface is particularly preferred, as it is also designed and configured for wired communication. This increases robustness. It is also possible, for example, to supply the control unit with electrical power via the communication interface, specifically a DC voltage that is preferably less than 20 V, such as 12 V or 5 V. This reduces the number of openings in the housing, thus improving its sealing.

[0035] Advantageously, the communication interface is galvanically isolated from the power supply connection. Preferably, the communication interface is also galvanically isolated from the DC circuit. As a result, safety requirements for the components connected to the communication interface are reduced, and it is, for example, impossible for a fault in the DC circuit or any on-board electrical system connected to the power supply connection to have a feedback effect on the communication interface and / or the components connected to it.

[0036] In an alternative embodiment, a mechanical switch is used instead of a semiconductor switch. This reduces the electrical resistance in the conductive state. It also allows for at least partial galvanic isolation of the respective supply connection from the DC circuit, thus increasing safety. In this configuration, a fuse may or may not be present. However, a particularly preferred configuration includes a semiconductor switch and a mechanical switch connected in series with it. This allows the semiconductor switch to interrupt the electrical current first, ensuring that the mechanical switch can always be operated, or at least when de-energized. Therefore, the formation of an arc is prevented.Redundancy is also provided by the semiconductor switch and the mechanical switch, thus increasing safety. If a fuse is also present, safety is further enhanced. The mechanical switch is preferably driven by a actuator, and the combination of actuator and mechanical switch is ideally designed as a relay. The actuator is preferably driven by the control unit, so that actuation occurs or can occur when a fault is detected and / or corresponding control commands are received. Alternatively, the mechanical switch can be manually actuated, for which a suitable actuating element is provided through the housing. For example, the mechanical switch may be single-pole or, more expediently, double-pole.It is therefore possible to completely isolate the respective supply connection galvanically from the DC circuit, which further increases safety.

[0037] For example, the switching state of the semiconductor switches is not monitored further. It is specifically assumed that the control of the half-liter switch always functions flawlessly and / or that the switching state (i.e., the electrical conductivity) of the semiconductor switch always corresponds to the control signal. Preferably, however, each semiconductor switch is assigned a signaling circuit. The signaling circuit serves to signal the electrical conductivity / switching state of the respective semiconductor switch and has a signal contact. The electrical potential provided there depends, in particular, on the current electrical conductivity / switching state. Specifically, the control unit is electrically and / or electronically connected to the signal contact so that the switching state of the semiconductor switch can be retrieved via this connection.

[0038] Each signaling circuit includes an additional semiconductor switch with two terminals. This additional semiconductor switch is, for example, a transistor such as a field-effect transistor. If the additional semiconductor switch is electrically conductive, the two terminals are connected with low resistance. If, however, the additional semiconductor switch is electrically non-conductive, no electrical current can flow between the two terminals, and they are connected with high resistance. Furthermore, the additional semiconductor switch has a control input. By applying and / or changing an electrical potential at this input, it is possible to change the switching state of the additional semiconductor switch, i.e., to switch it to an electrically conductive or non-conductive state.

[0039] One of the terminals of the additional semiconductor switch and the control input are electrically connected to each other via the semiconductor switch, for example directly or, more conveniently, via a resistor. The other terminal of the additional semiconductor switch is electrically connected to the signal contact. In particular, this terminal is directly connected to the signal contact. The signal contact is connected to a reference potential, preferably via an ohmic resistor. Specifically, the signal contact is connected to the control input via one or more additional resistors, thus providing a voltage divider and thereby realizing the reference potential. Therefore, no separately provided reference potential is required, which reduces complexity and simplifies assembly.

[0040] If the semiconductor switch is electrically conductive, the voltage / potential applied to the control input is too low for the other semiconductor switch to be electrically conductive. In this case, the electrical potential at the signal contact is determined by the reference potential or by any resistance. Conversely, if the semiconductor switch is electrically non-conductive, a comparatively high electrical potential is applied to the control input, causing the other semiconductor switch to be electrically conductive. Therefore, a different electrical potential is applied to the signal contact. Preferably, the signaling circuit is designed and / or connected to the other components of the power distributor in this way. This allows the signaling circuit to check the current state of the semiconductor switch, i.e., whether it is electrically conductive or non-conductive.This increases security.

[0041] For example, only the semiconductor switch is present, or at least the signaling circuit is only assigned to the respective semiconductor switch. Alternatively, a fuse is also present, and the fuse is, for example, additionally electrically connected between the terminal and the control input. Thus, it is always possible to determine whether an electrical current is flowing through the supply terminal. In a further development, a corresponding signaling circuit is assigned to each fuse as well as to each semiconductor switch. This enables a comparatively precise check of the current state of the connection of each supply terminal to the DC circuit.For example, if a mechanical switch is also present, it is assigned to one of the existing signaling circuits, or each mechanical switch is also assigned a corresponding signaling circuit. This allows for a comparatively granular assessment of the current state of the power distribution system.

[0042] For example, the housing is made of plastic. This allows for relatively free shaping of the housing and reduces manufacturing costs. However, it is particularly preferred that the housing is made of metal. This increases robustness. Electromagnetic compatibility is also improved in this way. Advantageously, the housing has a ground connection to which, in particular, electrical ground can be connected. For example, the housing is made of steel, preferably stainless steel. This increases robustness. Alternatively, the housing is made of aluminum. Consequently, weight is reduced and manufacturing is simplified. For example, the housing is cast from the metal, or preferably deep-drawn or die-cast.

[0043] Furthermore, the use of metal allows for the dissipation of heat from the interior of the housing. This eliminates the need for any openings, thus improving airtightness. Ideally, the power distribution unit, or preferably its housing, should meet a protection rating or class of at least IP 68, and preferably IP 69 or IP 69K. In other words, the power distribution unit is designed to achieve the corresponding protection class. Consequently, it is possible to install the power distribution unit in an unprotected location, such as on the floor or roof of a rail vehicle. This prevents the ingress of foreign particles into the housing that could otherwise cause a short circuit.Ideally, the power distribution box includes several covers or lids, which can be used to cover the connections, such as the supply connections and / or the feed-in connection, when not in use. Alternatively, these connections can be covered with a membrane that is pierced for electrical contact via the respective cable. This ensures a secure connection while still providing a relatively high level of sealing.

[0044] For example, the DC circuit is provided by means of several cables and / or busbars. However, the power distributor preferably comprises a printed circuit board (PCB) arranged within the housing, by means of which the DC circuit is provided. In particular, the PCB has several conductor tracks, and / or several busbars are attached to a body of the PCB. The body of the PCB is advantageously made of a glass-fiber reinforced epoxy resin. Advantageously, the PCB also includes any control unit and / or any semiconductor switches and / or any current sensors. In particular, these are each attached to the body of the PCB, advantageously by means of surface mounting. This simplifies manufacturing.Ideally, the supply connections and / or the feed-in connection and / or any switching device are also integrated into the circuit board, thus stabilizing the individual components of the power distributor. This simplifies assembly within the housing. It is also possible to manufacture the circuit board separately from the housing.

[0045] Preferably, the housing is made of metal, and the DC circuit is provided by means of a printed circuit board. These components are, for example, electrically connected to each other. This makes it possible, in particular, to also ground the printed circuit board, which simplifies wiring. However, it is especially preferred that the housing and the printed circuit board are galvanically isolated from each other. This prevents any feedback from the electrical ground to the power supply connection and any associated circuit, such as the vehicle electrical system. This also improves protection against electric shock and thus increases safety.

[0046] For example, the terminals of each supply connection are not electrically connected to each other. Preferably, however, they are short-circuited by means of a series connection consisting of a freewheeling diode and another surge protector. The freewheeling diode is oriented opposite to the voltage normally applied to it, so that no current flows through it under normal circumstances. Specifically, the respective series connection is offset towards the respective supply connection with respect to the semiconductor switch, fuse, and / or mechanical switch, if present. Thus, current can always flow via the series connection, regardless of whether the semiconductor switch / fuse / mechanical switch is electrically conductive or not.Due to the additional surge protection, it is advantageous to ensure that current is only conducted through the series circuit above a critical voltage, thus preventing undesirable effects that would impair the functionality of the power distributor. The series connection also allows for the interception of reverse currents, preventing discharge or polarity reversal of the DC circuit. This ensures the power distributor's continuous operation. Furthermore, this design allows for the dissipation of stored electrical energy, for example, if the semiconductor switch / fuse / mechanical switch is switched to a non-conductive state and an inductive load is connected to the respective supply terminal. This enhances safety.Furthermore, due to the series connection, it is possible to operate the connected load using pulse width modulation or the like, whereby the resulting switching peaks, especially if an inductive load is present, can be safely absorbed.

[0047] The vehicle is primarily land-based and preferably a rail vehicle, such as a locomotive or railcar. The power distribution unit is suitable for distributing electrical current, which is supplied, for example, by a generator or overhead line. This power supply unit ideally feeds an on-board electrical system, which carries a voltage of 110 V. The power distribution unit is preferably connected to this on-board electrical system.

[0048] The power distribution unit comprises a housing containing a power input and several supply connections, and a DC circuit that is electrically connected to the power input and each of the supply connections. Suitablely, each or at least some of the supply connections is connected to a corresponding electrical line leading to one or more associated auxiliary units. These units are thus powered via the power distribution unit. The power input, on the other hand, is preferably connected to the vehicle's electrical system.

[0049] The advantages and further training mentioned in connection with the power distributor can also be applied analogously to the motor vehicle and vice versa.

[0050] Exemplary embodiments of the invention are explained in more detail below with reference to a drawing. The drawing shows: Fig. 1. Schematic representation of a motor vehicle with a power distributor, Fig. 2. From a perspective view, the power distributor, which has a housing Fig. 3. A perspective view of the power distributor, with the housing not shown, so that a circuit board arranged inside is visible. Fig. 4 an alternative embodiment of the printed circuit board, Fig. 5 a simplified circuit diagram of the power distribution unit, Fig. 6 different characteristic curves, and Fig. 7 a simplified circuit diagram of a signaling circuit.

[0051] Corresponding parts are marked with the same reference symbols in all figures.

[0052] In Fig. Figure 1 schematically simplifies the representation of a motor vehicle 2 comprising several wheels 4. The motor vehicle 2 is designed as a rail vehicle, and the wheels 4 rest on rails (not shown) in their intended state. The motor vehicle 2 has an electrical system 6, which is supplied via an overhead line (not shown) or a generator. An electrical DC voltage of 110 V is always supplied via the electrical system 6. A power distribution unit 8 is connected to the electrical system 6, resulting in only a single connection to the electrical system 6. A supply line (not shown) is used for this connection, through which electrical energy is supplied from the electrical system 6 to the power distribution unit 8 during operation. Several loads 10 are connected to the power distribution unit 8 via individual lines 12, so that the electrical energy supplied to the power distribution unit 8 can be distributed among the loads 10.

[0053] In Fig. Figure 2 shows the power distributor 8 in perspective. It has a housing 14 made of aluminum and designed to be airtight. The housing 14, and therefore the power distributor 8, meets a protection rating of IP 69 K. The housing 14 has several openings 16, each containing a cover 18, which is designed as a rubber membrane and is firmly bonded to the housing 14. Each of the several supply connections 20 of a circuit board 22 is covered by a portion of the cover 18. Fig. Figure 3 shows the connection from a perspective view. The supply connections 20 are at least partially located within the openings 16, thus preventing the ingress of foreign particles between the supply connection 22 and the rim of the respective opening 16. Consequently, the supply connections 20 are integrated into the housing 40.

[0054] The printed circuit board 22 is completely enclosed within the metal housing 14. The printed circuit board 22 is spaced from the housing 14 by several spacers 24, thus providing galvanic isolation between them. The printed circuit board 22 comprises a body 26 made of a glass-fiber-reinforced epoxy resin, to which and in which several copper conductors (not shown) are attached / embedded. The supply terminals 20 are designed as cage clamp terminals and are surface-mounted on the body 26. The supply terminals 20 are configured differently, with two of them designed to accommodate cables with a relatively large diameter and three designed to accommodate cables with a reduced diameter.

[0055] A switching device 28, which is two-pole and has two switches 30, each designed as a circuit breaker, is also connected to the body 26. Therefore, the switching device 28 is also designed as a circuit breaker. Each switch 30 has a lever 32 that acts as an actuating element. The lever 32 actuates a mechanical switch (not shown) of the respective switch 30, thus changing its state. Consequently, it is possible to put it into an electrically conductive or non-conductive state. In doing so, the lever 32 cocks a switch lock (not shown). The two levers 32 are attached to each other, so that both switches 30 are always actuated together. The levers 32 are guided through a sealed opening in the housing 14, so that the switching device 28 can also be actuated from outside the housing 14.

[0056] Each switch 30 forms one pole 34 of a feed-in connection 36. The poles 34 are designed as screw terminals. Each pole 34 is assigned one of the openings 16 and lies close to its edge, thus preventing the ingress of foreign particles into the housing 14. The feed-in connection 36 is also integrated into the housing 14, allowing it to be contacted from outside the housing 14.

[0057] In Fig. Figure 4 shows a perspective view of a modified version of the circuit board 22. In this version, the body 26 is shortened, and the switching device 30 is not attached to it. For example, in this variant of the power distributor 8, the switching device 30 is either not present or is separate from the circuit board 22. Otherwise, there are no changes.

[0058] The supply terminals 20 and the feed-in terminal 36 are electrically connected by means of a DC circuit 38, as shown in the simplified circuit diagram of the Fig. Figure 5 shows the circuit. However, only two of the supply connections 20 are shown there. The DC circuit 38 is provided by means of conductor tracks on the circuit board 22 (not shown in detail). The DC circuit 38 is electrically connected to the supply connection 36 via the two-pole switching device 28. If the switches 30 of the switching device 28 are electrically conductive, the DC voltage of 110 V is also carried via the DC circuit 38.

[0059] The switching device 28 comprises a drive 40, by means of which the switches 30 are actuated, so that in addition to the lever 32, the switching state of the switches 30 can also be changed by means of the drive 40. The drive 40 is operated by means of a control unit 42. The control unit 42 adjusts the current supply to the drive 40. The control unit 42 comprises several components attached to the body 26 by means of surface mounting, including a programmable microcontroller 44 and a memory 56.

[0060] The electrical current carried by the switching device 28 and the electrical voltage applied between the poles 34 are detected by means of a sensor (not shown in detail) and, furthermore, at least implicitly, for example by means of the switch lock. Depending on this, the drive 40 is actuated and thus the switching device 28 is switched to the electrically conductive or non-conductive state.

[0061] The control unit 42 is connected via signal technology to a communication interface 48, which is also integrated into the housing 14, namely on the side in Fig. 2 shown on the opposite side of the housing 14. This makes it possible to connect a signal line or the like there. A low electrical voltage is also provided via the communication interface 48, which powers the control unit 42. The communication interface 48 is galvanically isolated from the power supply connection 36 and the DC circuit 38.

[0062] Each supply terminal 20 is connected to the DC voltage network 38 via a mechanical switch 50, a fuse 52, and a semiconductor switch 54, which are electrically connected in series. The mechanical switch 50 is located on the side facing the supply terminal 20, and the semiconductor switch 54 is located on the side facing the DC voltage circuit 38, with the fuse 52 positioned between them.

[0063] Each mechanical switch 50 is double-pole and is operated by means of a corresponding actuator 40, which is controlled by the control unit 42. Thus, it is also possible to open and close the mechanical switches 50 using the control unit 42, thereby switching them to the electrically non-conductive and electrically conductive states. The fuses 52 and the semiconductor switches 54, on the other hand, are single-pole. The semiconductor switches 54 are also operated by the control unit 42, so that it can also be set which semiconductor switch 54 is electrically conductive or electrically non-conductive.

[0064] In summary, it is thus possible to interrupt the electrical current between the DC circuit 38 and the respective supply terminal 20 by means of each semiconductor switch 44 and the associated mechanical switch 50, whereby galvanic isolation is achieved by means of the mechanical switches 50. The semiconductor switches 54 and the actuators 40 are actuated depending on control commands received via the communication interface 48.

[0065] Between each fuse 52 and the associated semiconductor switch 54, a current sensor 56 is connected, which is signal-connected to the control unit 42. Thus, it is possible to detect the electrical current supplied to the respective supply terminal 20 using the current sensor 56. In summary, each supply terminal 20 is electrically connected to the DC circuit 38 via the respective semiconductor switch 54, with the respective fuse 52 and the mechanical switch 50 being electrically connected in series with each semiconductor switch 54. Therefore, each current sensor 56 is assigned to one of the supply terminals 20 and signal-connected to the control unit 42.

[0066] The control unit 42 actuates the semiconductor switches 54 and the mechanical switches 50 depending on the measurement data acquired by the associated current sensor 52 and a respective characteristic curve 58. The measurement data is either the electric current directly or an electric voltage, namely when the current sensor 56 is configured as a shunt. Based on the electric voltage and the known value of the electrical resistance of a measuring resistor in the shunt, the electric current supplied to the supply terminal 20 can be determined.

[0067] The characteristic curves 58 are stored in memory 46 of the control unit 42, two of which are in Fig. Figure 6 shows the characteristic curves, one of which is assigned to each semiconductor switch 54. Each characteristic curve is used to assign a time duration t to an electric current I. As soon as the electric current I, which is greater than the rated current of the assigned supply terminal 20, has been carried for the assigned time duration t by means of the current sensor 54, the semiconductor switch 54 is switched to the non-conductive state. Furthermore, the mechanical switch 50 is also opened. Thus, each semiconductor switch 54, in conjunction with the respective current sensor 56 and the control unit 42, acts as a protective switch, thereby mimicking, for example, the operation of a thermal circuit breaker. After the semiconductor switch 54 has been opened, the respective mechanical switch 50 is also switched to the non-conductive state, for which purpose the respective actuator 40 is energized. This results in galvanic isolation.Since the electrical current is already interrupted, the mechanical switch 50 opens without voltage and therefore without an arc.

[0068] In the event of a malfunction of the respective semiconductor switch 54, the mechanical switch 50, or the control unit 42, a fuse 52 is provided as protection. This fuse trips in the event of excessive electrical current, thus interrupting the electrical current to the respective supply terminal 50. The characteristic curves 58 can be changed by programming. For this purpose, the characteristic curves 58 assigned to the different supply terminals 20 are reprogrammed into the memory 46 via the communication interface 48, so that they can be adapted to the respective load 10.

[0069] Each series circuit consisting of each semiconductor switch 54, the respective current sensor 56, and the associated fuse 52 has a surge protector 60 connected in parallel, so that the series circuit of each fuse 52 and the respective semiconductor switch 54 is bridged by the respective surge protector 60. A varistor is used as the surge protector 60, which reduces manufacturing costs and reduces the size. If an excessive voltage occurs at the respective series circuit, the electrical current is passed through the surge protector 60, thus dissipating the voltage and preventing damage to the semiconductor switches 54 and fuses 52.

[0070] Each supply terminal 20 is connected to a series circuit 62 consisting of a freewheeling diode 64 and a further overvoltage protection device 66, which is also designed as a varistor. Each supply terminal 20 is short-circuited by means of the respective series circuit 62, with the respective mechanical switch 50 being arranged between the respective supply terminal 20 and the respective series circuit 62. The freewheeling diodes 64 are oriented such that discharge of the DC circuit 38 is prevented.

[0071] The series circuit 62, for example, prevents any reverse currents that may occur if the respective semiconductor switch 54 is electrically non-conductive but the mechanical switch 50 is electrically conductive. These reverse currents occur particularly when the connected load 10 has an inductance. It also prevents voltage spikes that may occur, for example, if the load 10 connected to the respective supply terminal 20 is operated using pulse-width modulation. The additional surge protection 66 ensures that the series circuit 62 only conducts current when a sufficiently high voltage occurs that would otherwise damage other components of the power distribution unit 8.

[0072] The power distributor 8 also has several signaling circuits 68, each with a signal contact 70. Each signal contact 70 is connected to the control unit 42 both signal-wise and electrically, so that the electrical potential present at the respective signal contact 70 can be queried by the control unit 42. The signaling circuits 68 are assigned to the mechanical switches 50, the fuses 52, and the semiconductor switches 54, so that there are a total of 3 such signaling circuits 68 per supply connection 20, which are identical in construction, and are controlled by the Fig. Figure 7 shows a simplified circuit diagram. The signaling circuit 68 associated with one of the semiconductor switches 54 is shown.

[0073] The signaling circuit 68 includes a further semiconductor switch 72 with two terminals 74 and a control input 76. One of the terminals 74 is directly connected to the signal contact 70, and the other directly to a terminal of the associated semiconductor switch 54. The control input 76 is connected to the other terminal of the associated semiconductor switch 54 via a first diode 78, a first resistor 80, and a second diode 82, which are connected in series. Thus, one of the terminals 74 of the further semiconductor switch 72 is electrically connected to the control input 76 via the semiconductor switch 54, the second diode 82, the first resistor 80, and the first diode 78. The reverse bias of the first diode 78 and the second diode 82 is opposite, with the first diode 78 being oriented such that current can flow to the control input 76.

[0074] The semiconductor switch 54 is bypassed by a series circuit consisting of a second resistor 86 and a third diode 84, which is also electrically connected to terminal 74, which is not assigned to the signal contact 70, and which is conductive against the switching direction of the semiconductor switch 54. A third resistor 88 is connected to the signal contact 70, with the series circuit consisting of the second semiconductor switch 72 and the third resistor 88 being connected in parallel to the third diode 84. The signaling circuit 68 further comprises a fourth resistor 90, with the series circuit consisting of the second and fourth resistors 86 and 90 being connected in parallel to the second diode 82. The fourth resistor 90 is located on the side of the semiconductor switch 54 facing the DC circuit 38, so that the electrical potential specified by the DC circuit 38 is always present on this side.

[0075] In the signaling circuits 68 assigned to the mechanical switches 50 or the fuses 52, the respective mechanical switch 50 or the respective fuse 52 is located instead of the semiconductor switch 54.

[0076] When the respective semiconductor switch 54 is electrically non-conductive, an electric current flows through the second resistor 86, the fourth resistor 90, the first resistor 80, and the first diode 78 to the control input 76. As a result, the next semiconductor switch 72 is switched to the electrically conductive state, so that the electrical potential at the supply terminal 20, or at least the potential on the side of the semiconductor switch 54 facing the supply terminal 70, is present at the signal contact 70. The third diode 84 serves as a voltage-limiting element, and the second resistor 86 limits the electric current flowing into the signaling circuit 68. The voltage level that causes the next semiconductor switch 72 to become electrically conductive, and thus corresponds to a signaling level, is set by means of the first resistor 80 and the fourth resistor 90.This diode also sets the control current for the other semiconductor switch. The second diode 82 serves as a blocking diode and is conveniently identical in construction to the first diode 78.

[0077] If the semiconductor switch 44 is electrically conductive, a lower voltage is present across the second diode 82 and the semiconductor switch 54 than across the first resistor 80, the first diode 78, and the voltage between the control input 76 and one terminal 74 of the second semiconductor switch 72. Therefore, the electrical current flows through the semiconductor switch 54, and the electrical potential at the control input 76 is insufficient to convert the second semiconductor switch 72 into a conductive state. Consequently, the second semiconductor switch 72 is electrically non-conductive, and the electrical potential at the signal contact 70 is determined by the second and third resistors 86 and 88, as well as the DC circuit 38.Consequently, depending on whether the semiconductor switch 54 is electrically conductive or electrically non-conductive, a different electrical potential is present at the signal contact 70, so that the state of the associated semiconductor switch 54 can be checked by means of the control unit 54.

[0078] The invention is not limited to the embodiments described above. Rather, other variants of the invention can also be derived by a person skilled in the art without departing from the subject matter of the invention. In particular, all individual features described in connection with the individual embodiments can also be combined with one another in other ways without departing from the subject matter of the invention. Reference symbol list 2 motor vehicles 4-wheeler 6 On-board electrical system 8 power distribution boxes 10 Last 12 Line 14 cases 16 Breakthrough 18 Cover 20 supply connection 22 Circuit board 24 spacers 26 bodies 28 Switching device 30 switches 32 levers 34 poles 36 Feed-in connection 38 DC circuit 40 drive 42 Control unit 44 microcontrollers 46 storage 48 Communication interface 50 mechanical switches 52 fuse 54 semiconductor switches 56 Current sensor 58 characteristic curve 60 Surge protection 62 series connection 64 Freewheeling diode 66 additional surge protectors 68 Signaling circuit 70 Signal contact 72 more semiconductor switches 74 connection 76 Tax input 78 first diode 80 first resistance 82 second diode 84 third diode 86 second resistor 88 third resistance 90 fourth resistance t duration I electric current

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