Conveyor system and method for operating a conveyor system

Abstract

A conveyor system according to the invention comprises a stationary system part, which has at least one current-carrying primary conductor (2), and a plurality of active vehicles (14) and a plurality of passive vehicles (16) which are movable relative to the stationary system part, wherein each of the active vehicles (14) has a transmitter head (50) which comprises a secondary winding and a rectifier circuit. Each of the vehicles (14, 16) has a positive node (18) and a negative node (19), and the negative node (19) is connected to the negative nodes (19) of two adjacent vehicles (14, 16) via a respective negative line segment (9). Each of the active vehicles (14) has a protection unit (13) which comprises the positive node (18) and the negative node (19).and the protection unit (13) comprises a switchable first switching unit (S1) and a switchable second switching unit (S2), by means of which the positive node (18) is connected to the positive nodes (18) of two adjacent vehicles (14, 16) via a respective positive line segment (8). In each of the active vehicles (14), the rectifier circuit of the transmitter head (50) is electrically connected to the positive node (18) and to the negative node (19). Each of the passive vehicles (16) can be supplied with electrical energy exclusively via the line segments (8, 9) connected to the nodes (18, 19). The invention also relates to a method for operating a conveyor system according to the invention.

Description

[0001] The invention relates to a conveyor system comprising a stationary system part, which has at least one current-carrying primary conductor, and a plurality of active vehicles and a plurality of passive vehicles, which are movable relative to the stationary system part in a direction of travel. Each of the active vehicles has a transmitter head for contactless energy absorption, which comprises a secondary winding for inductive coupling with the primary conductor and a rectifier circuit for generating a direct voltage and / or a direct current. The invention also relates to a method for operating a conveyor system according to the invention.

[0002] From the publication DE 10 2014 010 915 B3, a conveyor system of this type is known, comprising a stationary system part and a system part that is movable relative to it, in particular along a conveyor line. A primary conductor is arranged along the conveyor line. The movable system part has vehicles referred to as conveyor elements, each of which has a secondary winding that is inductively coupled to the stationary primary conductor. Each vehicle is connected to the next adjacent vehicle via connectors and cables for power transmission.

[0003] A transformer for contactless energy absorption is known from DE 10 2021 005 981 A1. The transformer comprises a secondary winding for inductive coupling with a primary conductor and a rectifier circuit for generating a DC voltage.

[0004] DE 10 2009 007 969 A1 discloses a short-circuit protection device for limiting and interrupting short-circuit currents. The device comprises several switches and a monitoring and control device.

[0005] DE 103 29 914 A1 discloses a device for a power ring as a ring line for the electrical supply of devices. The device includes switches that can be used to connect or disconnect ring line elements from a node.

[0006] Each vehicle, with its inductive pickup, represents a DC source, which can have voltage source properties and / or current source properties. All DC sources together form a DC bus. The number of vehicle transmitters in inductive engagement is determined by the average power required on the DC bus and can be smaller than the total number of vehicles. Connection via the DC bus has the advantage of reducing the installed DC source power and / or simplifying the line cable installation, since not every section of the line needs to be supplied inductively.

[0007] The disadvantage of this wiring is that a fault on the DC bus, such as a short circuit, would result in the failure of the entire system. Furthermore, the high energies and currents would cause material damage, even burning cables. A cable break in a ring structure could potentially lead to increased line losses and potentially excessive heating of the current-carrying conductors, since the current is no longer distributed within the ring.

[0008] In the event of a short circuit on the DC bus, at least two protective elements are required to isolate the fault location and restore a safe operating state for the rest of the installation. For short circuits in the drive or DC source, one protective element in series with the faulty component is sufficient. Line interruptions cannot be detected by overcurrent protection components.

[0009] Since the size of the DC bus and its average installed power depend on the size of the system, the short-circuit currents, current gradients, and sustained short-circuit currents are also variable. This makes the installation of a fuse in the DC source and the drive unit expensive, as it must always be designed for the highest continuous current and the highest short-circuit current. The fuse element must be able to interrupt high DC currents. The protective elements within the DC bus are also subject to these maximum criteria. Furthermore, depending on how tightly the fault location needs to be isolated, many such protective elements must be used. The more protective elements used, the finer the localization of the fault location, but this also reduces selectivity and can lead to multiple tripping.

[0010] Fuses and circuit breakers can generally be used as protective elements if the tripping currents of the fuse elements can be reliably achieved without risk of accidental tripping. In applications with an extended ambient temperature range or different cooling conditions for the fuse elements, this requirement is usually not satisfactorily met. Fuse elements can be connected not only to the inlet and outlet of individual components, but also to protect segments of the chain or ring. However, to switch off a defective segment, the fuse elements must switch very precisely and selectively so that in the event of a fault, no more sub-segments are de-energized than necessary. Here, too, this requirement cannot usually be met satisfactorily if the protective elements have different operating temperatures.

[0011] The invention is based on the object of developing a conveyor system and a method for operating a conveyor system.

[0012] The object is achieved according to the invention by a conveyor system having the features specified in claim 1. Advantageous embodiments and further developments are the subject of the dependent claims. The object is also achieved by a method for operating a conveyor system having the features specified in claim 13. Advantageous embodiments and further developments are the subject of the dependent claims.

[0013] A conveyor system according to the invention comprises a stationary system component, which has at least one current-carrying primary conductor, and a plurality of active vehicles and a plurality of passive vehicles, which are movable relative to the stationary system component in a direction of travel. Each of the active vehicles has a transmitter head for contactless energy absorption, which comprises a secondary winding for inductive coupling with the primary conductor and a rectifier circuit for generating a direct voltage and / or a direct current.

[0014] Each of the vehicles has a positive node and a negative node. The negative node is connected to the negative nodes of two neighboring vehicles via a negative line segment.

[0015] Each of the active vehicles has a protection unit comprising the positive node and the negative node. The protection unit comprises a switchable first switching unit and a switchable second switching unit, by means of which the positive node is connected to the positive nodes of two adjacent vehicles via a positive line segment each. In each of the active vehicles, the rectifier circuit of the transformer head is electrically connected to the positive node and the negative node.

[0016] Each of the passive vehicles can be supplied with electrical power exclusively via the cable segments connected to the nodes. In particular, the passive vehicles do not have a transmitter head for contactless power collection.

[0017] In a conveyor system according to the invention, all vehicles can be supplied with electrical energy via the line segments connected to the nodes. A number of active vehicles are required, which, via the transmitters, receive energy from a primary conductor and feed it into the nodes. The supply of neighboring active vehicles, whose secondary winding of the transmitter is not inductively coupled to the primary conductor, is possible via the line segments, as is the supply of neighboring passive vehicles that do not have a transmitter. Passive vehicles are less expensive than active vehicles. Thus, the costs for a conveyor system according to the invention are advantageously reduced. The switching units in the protection unit of an active vehicle also allow the supply of neighboring vehicles to be interrupted if a fault is detected there.

[0018] According to an advantageous embodiment of the invention, each of the switching units of the protection unit can be switched to a closed state, in which current flow through the switching unit is enabled in both directions. Each of the switching units can also be switched to an open state, in which current flow through the switching unit in at least one direction is prevented. Thus, in the event of a fault, it is possible to isolate defective segments by selectively switching the switching units of the protection units of the vehicles, while intact segments remain in operation. This increases the availability of the vehicles in the event of a fault. Wiring cross-sections, in particular of the line segments, do not need to be designed for the entire short-circuit current. Furthermore, troubleshooting and diagnostics of the conveyor system during operation and under fault conditions are facilitated.

[0019] According to an advantageous embodiment of the invention, in the open state of the switching unit, a current flow from the positive line segment to the positive node is enabled through the respective switching unit. In the event of a fault, a current flow from a neighboring vehicle into the respective vehicle is thus enabled. However, a current flow from the vehicle to a neighboring vehicle is prevented.

[0020] According to an advantageous embodiment of the invention, each of the switching units of the protection unit comprises a parallel circuit consisting of a switchable switch and a diode. By switching the respective switching unit to the closed state, the respective switch is switched to a closed state in which current flow through the switch is enabled in both directions. By switching the respective switching unit to the open state, the respective switch is switched to an open state in which current flow through the switch in both directions is prevented. The diodes of the switching units are connected in such a way that current flow from the positive line segment to the positive node is enabled through the respective diode.For example, the switching units are each designed as a MOSFET (metal-oxide-semiconductor field-effect transistor), with each of the diodes representing a body diode of the respective switching unit. Metal-oxide-semiconductor field-effect transistors can be switched relatively quickly and with low loss, while also being cost-effective and reliable. In the event of a fault, current flow from a neighboring vehicle into the respective vehicle is thus enabled. However, current flow from the vehicle to a neighboring vehicle is prevented.

[0021] According to an advantageous embodiment of the invention, the protection unit comprises a first control unit and a second control unit for controlling the switching units, by means of which the switching units can be switched to the closed state and the open state. Upon detection of a fault, the switching units can thus be switched to the open state; after the fault has been rectified, the switching units can be switched to the closed state.

[0022] According to an advantageous embodiment of the invention, the protection unit comprises a first current sensor for measuring a first current flowing through the first switching unit and a second current sensor for measuring a second current flowing through the second switching unit. The first control unit evaluates the measurement of the first current, and the second control unit evaluates the measurement of the second current. In particular, each of the switching units can thus be separately switched to the open state if a value of a current flowing through the respective switching unit exceeds a predetermined limit.

[0023] According to an advantageous embodiment of the invention, the protection unit comprises a first voltage sensor for measuring a first voltage present between the first positive line segment and the first negative line segment, and a second voltage sensor for measuring a second voltage present between the second positive line segment and the second negative line segment. The first control unit evaluates the measurement of the first voltage, and the second control unit evaluates the measurement of the second voltage. The voltage sensors allow the connected line segments to be examined for faults, even if the corresponding switching unit is switched to the open state.

[0024] According to an advantageous embodiment of the invention, the protection unit comprises an internal voltage sensor for measuring an internal voltage present between the positive node and the negative node. The first control unit and / or the second control unit evaluates the internal voltage measurement. The internal voltage sensor allows for an investigation within the protection unit for faults,

[0025] According to an advantageous embodiment of the invention, at least one of the passive vehicles comprises a protection unit, which has the positive node and the negative node. The passive vehicle is thus designed almost identically to an active vehicle, except for the transmitter head. The conveyor system is thus designed flexibly, since a passive vehicle can be upgraded to an active vehicle by installing a transmitter head if necessary.

[0026] According to an advantageous embodiment of the invention, the positive node of at least one of the passive vehicles is directly connected to the positive line segments. The passive vehicle thus has no transmitter head or protection unit with switching units and is therefore particularly cost-effective.

[0027] According to an advantageous embodiment of the invention, the negative nodes of all vehicles are connected to the negative line segments in a ring structure. According to an advantageous embodiment of the invention, the positive nodes of all vehicles are connected to the positive line segments in a ring structure or in a chain structure. The ring structure allows the supply of a vehicle whose secondary winding of the transmitter head is not inductively coupled to the primary conductor, even if the switching units of a protective unit of a neighboring vehicle are switched to the open state. The chain structure allows this, provided that it is not the vehicle at the end of the chain.

[0028] According to an advantageous embodiment of the invention, the secondary winding of the transmitter head of at least one active vehicle is inductively coupled to the primary conductor. The rectifier circuit of the transmitter head feeds a direct voltage and / or a direct current between the positive node and the negative node. The rectifier circuit acts as a voltage source and / or a current source. The direct voltage serves, in particular, to supply electrical energy to a consumer of the vehicle, for example, a drive unit. Furthermore, the supply of neighboring vehicles whose secondary winding of the transmitter head is not inductively coupled to the primary conductor is possible via the line segments.

[0029] According to an advantageous embodiment of the invention, the stationary system component comprises a plurality of current-carrying primary conductors, which are arranged in sections within the conveyor system. The primary conductors are preferably arranged such that the secondary winding of the transmitter head of a vehicle is coupled to no more than one of the primary conductors at a time. Connecting the line segments in a ring structure or a chain structure ensures the supply of vehicles whose secondary winding is temporarily not coupled to a primary conductor. This allows the length of the primary conductors to be installed to be reduced. The arrangement with multiple energy sources also makes it possible to equip long lines and lines with increased power requirements if the feed-in power of a primary energy source is insufficient to supply all secondary consumers.

[0030] A method for operating a conveyor system according to the invention is also proposed. Each of the switching units of a protective unit can be switched to a closed state, in which current flow through the switching unit is enabled in both directions, and each of the switching units of a protective unit can be switched to an open state, in which current flow through the switching unit in at least one direction is prevented. Each of the switching units of a protective unit is switched to the open state when a value of a current flowing through the respective switching unit exceeds a predetermined limit.

[0031] For example, if there is a short circuit on the connected line segments, switching the relevant switching unit to the open state prevents current flow from the protection unit to the short circuit on the connected line segments. The supply to the vehicle's own consumer remains intact.

[0032] According to an advantageous embodiment of the invention, both switching units of the protection unit are switched to the open state if a value of at least one current flowing through one of the switching units exceeds a predetermined limit. Thus, if a short circuit occurs on only one of the connected line segments, both switching units are switched to the open state.

[0033] According to an advantageous development of the invention, the first switching unit is subsequently switched to the closed state when a first voltage applied between the first positive line segment and the first negative line segment is within a desired range. If a short circuit occurs between the first positive line segment and the first negative line segment, the first voltage remains in a range close to 0 V. In this case, the first switching unit remains in the open state.

[0034] According to an advantageous development of the invention, the second switching unit is subsequently switched to the closed state when a second voltage applied between the second positive line segment and the second negative line segment is within the desired range. If a short circuit occurs between the second positive line segment and the second negative line segment, the second voltage remains in a range close to 0 V. In this case, the second switching unit remains in the open state.

[0035] All protection units on all vehicles operate in this way. Only the segment containing the short circuit is switched off. The closed ring structure becomes an open structure, and a connected chain structure becomes two separate chains. The affected protection units located closest to the short circuit signal the detected short circuit. This allows for quick spatial isolation of the short circuit.

[0036] If a short circuit occurs in the vehicle's consumer, the defective consumer remains connected only to the vehicle's own protection unit. The short-circuit current is locally limited to the value of the transmitter. If the transmitter has short-circuit current limitation or current source properties, overheating caused by excessive short-circuit currents is reliably prevented. The closed ring structure becomes an open structure, and a connected chain structure becomes two separate chains. The affected protection units, which are spatially closest to the short circuit, signal the detected short circuit. This allows for rapid spatial localization of the short circuit.

[0037] If a short circuit occurs in the vehicle's transformer head, the defective transformer head remains connected only to the load of the vehicle's own power supply. The short-circuit current is locally limited to the transformer head's current. Overheating caused by excessive short-circuit currents is reliably prevented. The closed ring structure becomes an open structure. The affected protection units located closest to the short circuit signal the detected short circuit. This allows for rapid spatial isolation of the short circuit.

[0038] If a short circuit occurs in the protection unit, particularly between the positive and negative nodes, the internal voltage remains close to 0 V. In this case, the switching units of the protection units of neighboring vehicles are each switched to the open state. The defective protection unit remains connected only to the load of its own vehicle. The short-circuit current is locally limited to the value of the transmitter head. Overheating due to excessive short-circuit currents is reliably prevented. The closed ring structure becomes an open structure. The affected protection units, which are spatially closest to the short circuit, signal the detected short circuit. This allows the short circuit to be spatially isolated quickly.

[0039] If a line break occurs in a line segment between two protection units of adjacent vehicles, no current flows through the connected switching unit. Therefore, if a current is measured in only one of the current sensors with the switching units in the closed state and the ring structure, this indicates a line break or a shutdown of a protection unit of an adjacent vehicle.

[0040] If both switching units of a protection unit are open, no current can flow from the protection unit to the adjacent vehicles. If there is voltage in the transformer but no voltage at the load, there is an open circuit within the protection unit between the transformer and the load.

[0041] The invention is not limited to the combination of features in the claims. Further possible combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent to those skilled in the art, particularly from the problem and / or the problem posed by comparison with the prior art.

[0042] The invention will now be explained in more detail with reference to the accompanying drawings. The invention is not limited to the exemplary embodiments shown in the drawings. The drawings only represent the subject matter of the invention schematically. They show: Fig. 1: a schematic representation of a conveyor system, Fig. 2: a schematic representation of an active vehicle of the conveyor system and Fig. 3: a schematic representation of a conveyor system according to an alternative embodiment.

[0043] Fig. Figure 1 shows a schematic representation of a conveyor system. The conveyor system comprises a stationary system section, a plurality of passive vehicles 16, and a plurality of active vehicles 14, which are movable relative to the stationary system section in a direction of travel 11. The stationary system section forms a closed track, and the vehicles 14, 16 circulate within the closed track. Several vehicles 14, 16, or even all vehicles 14, 16, are mechanically coupled to one another and circulate together around the stationary system section.

[0044] The stationary system component comprises a power source 1 and a current-carrying primary conductor 2. The primary conductor 2 is electrically connected to the power source 1 and carries an alternating current supplied by the power source 1. The primary conductor 2 is laid in a closed conductor loop and has an inductance. The alternating current flowing through the primary conductor 2 has, for example, a frequency of 50 kHz and an effective current of 30 A.

[0045] Each of the active vehicles 14 has a transmitter head 50 for contactless energy reception. The transmitter head 50 comprises a secondary winding for inductive coupling to the primary conductor 2 and a rectifier circuit for generating a direct voltage and / or a direct current. If the secondary winding of the transmitter head 50 is inductively coupled to the primary conductor 2, energy can be transmitted contactlessly from the energy source 1 to the transmitter head 50.

[0046] Depending on the current position of an active vehicle 14 relative to the stationary system component, the secondary winding of the transmitter head 50 is coupled to the primary conductor. There are positions at which the secondary winding of the transmitter head 50 is coupled to the primary conductor, and there are positions at which the secondary winding of the transmitter head 50 is not coupled to the primary conductor. At least one of the active vehicles 14 is always in a position at which the secondary winding of the transmitter head 50 is coupled to the primary conductor.

[0047] Each of the active vehicles 14 and each of the passive vehicles 16 has a load 7. The load 7 is, for example, a drive unit for driving the vehicle 14, 16 along the stationary system section. The drive unit comprises, for example, a three-phase drive motor and an inverter.

[0048] Each of the active vehicles 14 also has a protection unit 13. The protection unit 13 is electrically connected to the transformer 50 and to the load 7. If the secondary winding of the transformer 50 is inductively coupled to the primary conductor 2, the rectifier circuit of the transformer 50 feeds a direct voltage and / or a direct current into the protection unit 13. The protection unit 13 transmits electrical energy in the form of a direct voltage and / or a direct current to the load 7, in particular to its inverter.

[0049] In the illustration shown here, each of the passive vehicles 16 also has a protection unit 13. However, the passive vehicles 16 do not have a transmitter head 50. The protection unit 13 is electrically connected to the load 7.

[0050] Each of the active vehicles 14 and each of the passive vehicles 16 further comprises a communication device (not shown here). The communication device enables data transmission to another vehicle 14, 16 and to a central server. The stationary system component comprises, for example, a slotted waveguide, and each of the vehicles 14, 16 has an antenna extending into the slotted waveguide.

[0051] The protection unit 13 of each active vehicle 14 is electrically connected to the protection units 13 of two adjacent vehicles 14, 16 via negative line segments 9 and positive line segments 8, respectively. The protection unit 13 of each passive vehicle 16 is also electrically connected to the protection units 13 of two adjacent vehicles 14, 16 via negative line segments 9 and positive line segments 8, respectively. The protection units 13 of the vehicles 14, 16 and the line segments 8, 9 are electrically connected to one another in a ring structure.

[0052] If the secondary winding of the transmitter head 50 of one of the active vehicles 14 is not coupled to the primary conductor, electrical energy can be transmitted from the protection unit 13 of a neighboring vehicle 14, 16. Electrical energy can also be transmitted from the protection unit 13 of a neighboring vehicle 14, 16 to each passive vehicle 16.

[0053] Fig. Figure 2 shows a schematic representation of an active vehicle 14 of the conveyor system. As already mentioned, the active vehicle 14 has a protection unit 13, a load 7, and a transmitter 50. The protection unit 13, the load 7, and the transmitter 50 are electrically connected to one another.

[0054] The protection unit 13 comprises a positive node 18 and a negative node 19. The rectifier circuit of the transformer 50 is electrically connected to the positive node 18 and to the negative node 19. If the secondary winding of the transformer 50 is inductively coupled to the primary conductor 2, the rectifier circuit of the transformer 50 feeds a direct voltage and / or a direct current between the positive node 18 and the negative node 19. The load 7 is also electrically connected to the positive node 18 and the negative node 19 and is supplied with electrical energy via the nodes 18, 19.

[0055] The negative node 19 of the protection unit 13 is connected to the negative nodes 19 of the protection units 13 of two adjacent vehicles 14, 16 via a negative line segment 9 each. The negative nodes 19 of all vehicles 14, 16 are interconnected with the negative line segments 9 in a ring structure.

[0056] The protection unit 13 comprises a switchable first switching unit S1 and a switchable second switching unit S2. By means of the switching units S1, S2, the positive node 18 of the protection unit 13 is connected to the positive nodes 18 of the protection units 13 of two adjacent vehicles 14, 16 via a positive line segment 8 each. The positive nodes 18 of all vehicles 14, 16 are interconnected with the positive line segments 8 in a ring structure.

[0057] Each of the switching units S1, S2 comprises a parallel circuit consisting of a switchable switch and a diode. The switching units S1, S2 are designed, for example, as a metal-oxide-semiconductor field-effect transistor, in particular as a normally-blocking n-channel MOSFET. Each of the said diodes represents a body diode of the respective switching unit S1, S2. However, it is also conceivable for the diodes to be designed as switching elements separate from the switches.

[0058] Each of the switching units S1, S2 can be switched to a closed state and an open state. Switching the respective switching unit S1, S2 to the closed state switches the respective switch to a closed state. Switching the respective switching unit S1, S2 to the open state switches the respective switch to an open state.

[0059] When the switch of the respective switching unit S1, S2 is closed, current flow through the switch is possible in both directions. Therefore, when one of the switching units S1, S2 is closed, current flow through the switching unit S1, S2 is possible in both directions.

[0060] When the switch of the respective switching unit S1, S2 is switched to the open state, current flow through the switch is prevented in both directions. Therefore, when one of the switching units S1, S2 is switched to the open state, current flow is only permitted in one direction through the diode of the respective switching unit S1, S2. Therefore, when one of the switching units S1, S2 is switched to the open state, current flow through the respective switching unit S1, S2 is permitted in one direction and prevented in the opposite direction.

[0061] The diodes of the switching units S1, S2 are connected in such a way that a current flow from the positive line segment 8 to the positive node 18 is enabled through the diode of the respective switching unit S1, S2. In the open state of the switching unit S1, S2, a current flow from the positive line segment 8 to the positive node 18 is thus enabled through the respective switching unit S1, S2.

[0062] The protection unit 13 comprises a first control unit 21 and a second control unit 22 for controlling the switching units S1, S2. By means of the first control unit 21, the first switching unit S1 can be switched to the closed state and the open state.

[0063] By means of the second control unit 22, the second switching unit S2 can be switched into the closed state and into the open state.

[0064] The protection unit 13 comprises a first current sensor 31 for measuring a first current I1 flowing through the first switching unit S1 and a second current sensor 32 for measuring a second current I2 flowing through the second switching unit S2. The first control unit 21 evaluates the measurement of the first current I1. The second control unit 22 evaluates the measurement of the second current I2.

[0065] The protection unit 13 comprises a first voltage sensor for measuring a first voltage U1 present between the first positive line segment 8 and the first negative line segment 9, and a second voltage sensor for measuring a second voltage U2 present between the second positive line segment 8 and the second negative line segment 9. The first control unit 21 evaluates the measurement of the first voltage U1. The second control unit 22 evaluates the measurement of the second voltage U2.

[0066] The protection unit 13 includes an internal voltage sensor for measuring an internal voltage Ux present between the positive node 18 and the negative node 19. The first control unit 21 evaluates the measurement of the internal voltage Ux. The second control unit 22 also evaluates the measurement of the internal voltage Ux.

[0067] A passive vehicle 16, unlike the active vehicle 14 shown here, does not have a transmitter head 50. In one possible embodiment, a passive vehicle 16 has a protection unit 13, which is designed similarly to the protection unit 13 of an active vehicle 14. The protection unit 13 is electrically connected to the load 7.

[0068] In another possible embodiment, a passive vehicle 16 also has no protection unit 13 and thus no switching units S1, S2. The passive vehicle 16 has a positive node 18 and a negative node 19. The nodes 18, 19 are electrically connected to the load 7. Furthermore, the positive node 18 is directly connected to the positive line segments 8.

[0069] Fig. Figure 3 shows a schematic representation of a conveyor system according to an alternative embodiment. The conveyor system according to the alternative embodiment is largely similar to that shown in Fig. 1. In the following, the differences to the conveyor system shown in Fig. 1 shown conveyor system.

[0070] The conveyor system according to the alternative embodiment also comprises a stationary system part and a plurality of vehicles 14, 16, which are movable relative to the stationary system part in a direction of travel 11. The stationary system part forms a closed track, and the vehicles 14, 16 circulate within the closed track. Several vehicles 14, 16, or even all vehicles 14, 16, are mechanically coupled to one another and circulate together around the stationary system part.

[0071] The stationary system component comprises two energy sources 1 and two current-carrying primary conductors 2. Each of the primary conductors 2 is electrically connected to one of the energy sources 1 and carries an alternating current supplied by the respective energy source 1. Each of the primary conductors 2 is laid in a closed conductor loop and has an inductance. The alternating current flowing through the primary conductor 2 has, for example, a frequency of 50 kHz and a current of 30 A.

[0072] The primary conductors 2 are arranged in sections within the conveyor system. The primary conductors 2 are arranged such that the secondary winding of the transmitter head 50 of an active vehicle 14 is coupled to no more than one of the two primary conductors 2 at a time. Thus, during a circuit on the closed track, each of the active vehicles 14 temporarily reaches locations where the secondary winding of the transmitter head 50 is not coupled to any of the primary conductors 2. List of reference symbols 1 energy source 2 primary conductors 7 consumers 8 positive line segment 9 negative line segment 11 Direction of travel 13 Protection Unit 14 active vehicles 16 passive vehicle 18 positive node 19 negative node 21 first control unit 22 second control unit 31 first current sensor 32 second current sensor 50 pick-up head S1 first switching unit S2 second switching unit I1 first current I2 second current U1 first voltage U2 second voltage Ux internal voltage QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2014 010 915 B3

[0002] DE 10 2021 005 981 A1

[0003] DE 10 2009 007 969 A1

[0004] DE 103 29 914 A1

[0005]

Claims

[1] Conveyor system, comprising a stationary part of the system which has at least one current-carrying primary conductor (2), and a plurality of active vehicles (14) and a plurality of passive vehicles (16) which are movable relative to the stationary system part in a direction of travel (11), wherein each of the active vehicles (14) has a transmitter head (50) for contactless absorption of energy, which comprises a secondary winding for inductive coupling with the primary conductor (2) and a rectifier circuit for generating a direct voltage and / or a direct current, characterized by , that each of the vehicles (14, 16) has a positive node (18) and a negative node (19), and that the negative node (19) is connected to the negative nodes (19) of two adjacent vehicles (14, 16) via a negative line segment (9), and that each of the active vehicles (14) has a protection unit (13) comprising the positive node (18) and the negative node (19), and that the protection unit (13) comprises a switchable first switching unit (S1) and a switchable second switching unit (S2), by means of which the positive node (18) is connected to the positive nodes (18) of two adjacent vehicles (14, 16) via a positive line segment (8) each, and in that in each of the active vehicles (14) the rectifier circuit of the transmitter head (50) is electrically connected to the positive node (18) and to the negative node (19), and in that each of the passive vehicles (16) can be supplied with electrical energy exclusively via the line segments (8, 9) connected to the nodes (18, 19). [2] Conveyor system according to claim 1, characterized by , that each of the switching units (S1, S2) of the protective unit (13) can be switched into a closed state in which a current flow through the switching unit (S1, S2) is possible in both directions, and that each of the switching units (S1, S2) can be switched into an open state in which a current flow through the switching unit (S1, S2) in at least one direction is prevented. [3] Conveyor system according to claim 2, characterized by that in the open state of the switching unit (S1, S2) a current flow from the positive line segment (8) to the positive node (18) is possible through the respective switching unit (S1, S2). [4] Conveyor system according to one of claims 2 to 3, characterized by , that each of the switching units (S1, S2) of the protection unit (13) comprises a parallel circuit of a switchable switch and a diode, and that by switching the respective switching unit (S1, S2) into the closed state, the respective switch is switched into a closed state in which a current flow through the switch is possible in both directions, and that by switching the respective switching unit (S1, S2) into the open state, the respective switch is switched into an open state in which a current flow through the switch in both directions is prevented, and that the diodes of the switching units (S1, S2) are connected in such a way that a current flow from the positive line segment (8) to the positive node (18) is enabled by the respective diode. [5] Conveyor system according to one of claims 2 to 4, characterized bythat the protective unit (13) comprises a first control unit (21) and a second control unit (22) for controlling the switching units (S1, S2), by means of which the switching units (S1, S2) can be switched into the closed state and into the open state. [6] Conveyor system according to claim 5, characterized by , that the protection unit (13) comprises a first current sensor (31) for measuring a first current (I1) flowing through the first switching unit (S1) and a second current sensor (32) for measuring a second current (I2) flowing through the second switching unit (S2), and that the first control unit (21) evaluates the measurement of the first current (I1), and that the second control unit (22) evaluates the measurement of the second current (I2). [7] Conveyor system according to one of claims 5 to 6, characterized by , that the protection unit (13) comprises a first voltage sensor for measuring a first voltage (U1) applied between the first positive line segment (8) and the first negative line segment (9) and a second voltage sensor for measuring a second voltage (U2) applied between the second positive line segment (8) and the second negative line segment (9), and that the first control unit (21) evaluates the measurement of the first voltage (U1), and that the second control unit (22) evaluates the measurement of the second voltage (U2). [8] Conveyor system according to one of claims 5 to 7, characterized by , that the protection unit (13) comprises an internal voltage sensor for measuring an internal voltage (Ux) present between the positive node (18) and the negative node (19), and that the first control unit (21) and / or the second control unit (22) evaluates the measurement of the internal voltage (Ux). [9] Conveyor system according to one of the preceding claims, characterized by that at least one of the passive vehicles (16) has a protection unit (13) which comprises the positive node (18) and the negative node (19). [10] Conveyor system according to one of the preceding claims, characterized by that in at least one of the passive vehicles (16) the positive node (18) is directly connected to the positive line segments (8). [11] Conveyor system according to one of the preceding claims, characterized bythat the negative nodes (19) of all vehicles (14, 16) are connected to the negative line segments (9) in a ring structure, and / or that the positive nodes (18) of all vehicles (14, 16) are connected to the positive line segments (8) in a ring structure or in a chain structure. [12] Conveyor system according to one of the preceding claims, characterized by that the stationary part of the system has a plurality of current-carrying primary conductors (2) which are arranged in sections in the conveyor system. [13] Method for operating a conveyor system according to one of the preceding claims, characterized by , that each of the switching units (S1, S2) of a protective unit (13) can be switched into a closed state in which a current flow through the switching unit (S1, S2) is possible in both directions, and that each of the switching units (S1, S2) of a protective unit (13) can be switched into an open state in which a current flow through the switching unit (S1, S2) in at least one direction is prevented, and that each of the switching units (S1, S2) of a protective unit (13) is switched to the open state when a value of a current (I1, I2) flowing through the respective switching unit (S1, S2) exceeds a predetermined limit value. [14] Method according to claim 13, characterized by that both switching units (S1, S2) of the protective unit (13) are switched to the open state when a value of at least one current (I1, I2) flowing through one of the switching units (S1, S2) exceeds the predetermined limit value. [15] Method according to claim 14, characterized bythat the first switching unit (S1) is subsequently switched to the closed state when a first voltage (U1) applied between the first positive line segment (8) and the first negative line segment (9) is in a desired range, and / or that the second switching unit (S2) is subsequently switched to the closed state when a second voltage (U2) applied between the second positive line segment (8) and the second negative line segment (9) is in the desired range.

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