Energy management system for a vehicle

Abstract

The invention relates to an energy management system (1) for a vehicle, comprising: at least one electronic load (41, 42, 43, 52, 53, 60) for providing a vehicle function; at least one energy source (10) for supplying the at least one electronic load (41, 42, 43, 52, 53, 60) with electrical energy, the at least one electronic load (41, 42, 43, 52, 53, 60) being connectable to the at least one energy source via at least one connecting line (80, 90); at least one electrical resistor unit (20), which has at least one electrical resistor (20a), the at least one electrical resistor (20a) being connectable to the at least one connecting line (80, 90); and at least one control device (21, 70) which is configured to connect the at least one electrical resistor (20a) of the at least one electrical resistor unit (20) to the at least one connecting line (80) in the event of a fault signal.

Description

[0001] DESCRIPTION

[0002] Energy management system for a vehicle

[0003] The present invention relates to an energy management system for a vehicle, a method for operating such an energy management system, a computer program product for carrying out such a method, and a vehicle.

[0004] Electric vehicles, or vehicles with other electrical components, typically have a DC (direct current) connection branch, originating from an energy source such as a traction battery. This branch supplies power to various components, particularly high-voltage devices like a traction motor, including inverters and / or high-voltage compressors. In the event of an accident or a disconnection of a component, the voltage in the high-voltage circuit must be reduced or at least dissipated. This requires the installation of additional components to enable active voltage reduction. These additional components, in turn, increase the complexity and cost of a vehicle equipped with this system.

[0005] The object of the present invention is to provide an energy management system and a corresponding use that can reduce voltage in the event of a fault and / or when consumers are disconnected.

[0006] The problem is solved by the subject matter of the subordinate claims. Advantageous further developments are the subject matter of the dependent claims.

[0007] According to the invention, an energy management system for a vehicle comprises at least one electronic consumer for providing a vehicle function, at least one energy source for supplying the at least one electronic consumer with electrical energy, wherein the at least one electronic consumer is connectable to the at least one energy source via at least one connecting line, and at least one electrical resistance unit comprising at least one electrical resistance, wherein the at least one electrical resistance is connectable to the at least one connecting line. The energy management system also comprises at least one control device configured to connect the at least one electrical resistance of the at least one electrical resistance unit to the at least one connecting line when a fault signal is present.

[0008] An electronic device used to provide a vehicle function can be, in particular, a high-voltage device, such as an electric motor for propulsion. Other examples of high-voltage electronic devices include high-voltage auxiliary components, such as an air conditioning compressor, a compressed air compressor, a heater or water heater, or a power steering pump. Generally, an electrical device is understood here as a unit that is powered by electrical energy to perform at least one predetermined function. The term "device" does not preclude the possibility that a device is a component or unit that not only requires electrical energy to perform a function but can also, conversely, provide and / or transmit electrical energy.

[0009] Electrical energy is supplied to at least one consumer by at least one energy source. This energy source is preferably a generator or a storage medium for storing electrical energy. In particular, the storage medium can be discharged and recharged.

[0010] According to the invention, the at least one electrical resistance unit is designed to be connected to the at least one connecting line in order to dissipate excess energy or convert it into heat via the electrical resistance. This function is implemented via the at least one control device, which is configured to connect the at least one electrical resistance unit to the at least one connecting line when an error signal is present. This reduces the electrical potential or voltage in the energy source circuit by switching on the electrical resistance.

[0011] The fault signal represents the occurrence of a situation outside of normal vehicle operation, where an applied high voltage, for example 800 V, could lead to property damage and, in particular, personal injury. In other words, the fault signal represents situations requiring voltage reduction to a safe level. This voltage reduction from 800 V can be limited to such an extent that the supply of electrical power to electronic devices remains at least partially possible. The term "partially" refers, for example, to some electronic devices that can generally be operated at a lower voltage level, and / or to a portion of an electronic device's functionality that can be maintained even at a lower voltage level.For this purpose, for example, the voltage can be reduced from 800 V as the high voltage to be reduced to 20 V to 80 V, in particular 60 V.

[0012] Accordingly, a safety function is integrated by reducing the voltage via the electrical resistance, in order to prevent personal injury or fire caused by a flashover.

[0013] The fault signal can be generated by a fault detection unit and transmitted to the control device. For example, voltage detection units and / or current detection units can be provided that detect a fault requiring a voltage reduction, in particular a voltage reduction from a high-voltage level to a low-voltage level. The fault detection units can evaluate the detection signals directly to output a fault signal. Alternatively, the detection signals can be evaluated by the control device. As an alternative or supplement to fault detection units that automatically detect fault conditions based on monitoring or at least transmit signals that can be evaluated for fault identification, a fault signal can also be transmitted to the energy management system via a fault input device.This can be achieved through manual error input and / or by transmitting a signal wirelessly or via a connection interface from an external control unit. The error signal is specifically directed at a fault condition in the energy management system, for example, an electronic consumer or the energy source, but can also affect another vehicle component where, in the event of a fault, a safe operating state of the vehicle is required, in the sense of voltage reduction for vehicle components.

[0014] The term "error signal" can also refer to an intentional disconnection of at least one electronic device from the energy management system. This is only possible without errors or risk if the voltage level of the at least one electronic device has been reduced to a safe level before the disconnection. Accordingly, upon input of a disconnection intention or detection of the activation of a disconnection mechanism, the connection process of the electrical braking resistor to the at least one connecting line can be initiated by the control device. The control device can be configured to allow the disconnection of the at least one electronic device only after the current voltage level across the electrical braking resistor has been reduced to a safe level.

[0015] In one embodiment, the at least one electrical resistance unit is at least one electrical braking resistance unit comprising at least one electrical braking resistor. The at least one electrical braking resistance unit can be assigned, for example, to a regenerative brake in electric or hybrid vehicles, i.e., a drive motor or electric motor in recuperation mode, in order to convert and dissipate excess braking energy, which cannot be used otherwise, such as for charging a battery, via the electrical braking resistor during conventional operation. In the context of the present invention, the function of the at least one electrical braking resistance unit or the at least one electrical braking resistor is extended to include the functionality of compensating for fluctuations in electrical energy.Accordingly, the at least one electrical braking resistor unit can be considered an additional consumer unit alongside the at least one electronic consumer. Nevertheless, a distinction must be made between the at least one electrical braking resistor unit and the at least one electronic consumer. This is because the at least one electrical braking resistor unit provides a separate functionality within the energy management system that goes beyond the execution of the function otherwise associated with a braking resistor unit.

[0016] Where the following description refers to an electrical braking resistor unit or an electrical resistor as an example, the described functionalities are equally transferable to a general electrical resistor unit or a general electrical resistor, provided the description is not specifically directed at braking resistor-specific functionalities. Conversely, functionalities of the electrical resistor unit or the electrical resistor itself are also transferable analogously to the electrical braking resistor unit or the electrical braking resistor.

[0017] In one configuration, the fault signal is representative of a vehicle accident, a malfunction of a component of the energy management system, and / or a fault condition that can be influenced by the energy management system. As explained above, the fault signal represents a vehicle condition or a condition of a vehicle component, such as at least one electronic consumer, in which, specifically for safety reasons, a voltage level should or must be reduced to a range that is not critical for other vehicle components and / or persons.

[0018] Accordingly, a fault condition could be a vehicle accident requiring voltage reduction to protect rescue personnel or other individuals. The fault signal can be generated automatically upon airbag deployment or other impact detection. Alternatively or additionally, as with other fault conditions, manual input is possible. Other fault signals may relate to the failure or disconnection of an electronic component. Disconnection can also occur intentionally, for example, during repair and maintenance work. A fault condition can also occur if a component of the energy management system exhibits operating behavior outside of predetermined parameters. For example, unexpected voltage spikes can constitute a fault condition.

[0019] Accordingly, if a predetermined voltage value is exceeded, which is detected, for example, at the at least one electronic device and / or a corresponding connecting line for the supply of electrical energy, the at least one electrical resistor of the at least one electrical braking resistor unit is connected to the at least one connecting line. The voltage can then be dissipated across the at least one electrical resistor via this connection.

[0020] The control device can be configured to distinguish between different fault signals and react to them differently. For example, in the case of a fault signal representing a vehicle accident, the control device can immediately connect at least one electrical resistor of at least one electrical brake resistor unit to at least one connecting line. On the other hand, in the case of another fault signal, such as one related to voltage and / or current monitoring, the control device can only initiate the connection if a predetermined limit is exceeded for a predetermined period and / or with a predetermined frequency within a predetermined period.

[0021] In one embodiment, the at least one control device is an internal control device of the at least one electrical resistance unit or an external control device of the energy management system, which is connected to the at least one electrical resistance unit and / or the at least one connecting line.

[0022] In the case of at least one control device acting as an internal control device of at least one electrical resistance unit, an existing energy management system can be easily retrofitted without having to adapt an external control device. In the case of at least one control device acting as an external control device of the energy management system, where "external" is to be understood in relation to the term "internal," meaning not integrated into the at least one electrical resistance unit, the opposite advantage can arise: adapting the energy management system without modifying the at least one electrical resistance unit. Finally, it is also possible to provide at least one internal and at least one external control device, which are at least partially redundant to each other or complement each other in their control functions.Complementary control involves, for example, control by the internal control device in response to a first type of fault signal and by the external control device in response to a second type of fault signal. The first fault signal could be a fault signal indicating a malfunction of at least one electronic component, while the second type could represent a fault signal resulting from a vehicle accident.

[0023] In one embodiment, the at least one control device controls at least one switch or has at least one switch to connect or disconnect the at least one electrical resistor from the at least one connecting line.

[0024] In particular, the at least one switch and the at least one control device are configured such that the at least one electrical resistor can not only be connected to the at least one connecting line, but the connection can also be disconnected. Alternatively, only the switch can be configured to disconnect the connection, with the disconnection process being controlled by another control device and / or by hardware components integrated into the switch that automatically react to a state intended for disconnection. Such hardware components can also be provided in addition to corresponding control by the at least one control device.

[0025] The at least one switch can be arranged in the at least one connecting line between the at least one electrical resistor and the at least one electronic load and can be controlled by the at least one control device or encompassed by the at least one control device, for example, the at least one external control device. Alternatively, the at least one switch can be integrated into the at least one electrical resistor unit. If the at least one switch is integrated into the electrical resistor unit, the at least one switch can be controlled by the external and / or internal control device or encompassed by the internal control device.

[0026] The term "switch" generally encompasses components that can perform a corresponding switching function via a control system and / or corresponding hardware components.

[0027] In particular, at least one switch is configured to switch independently depending on the fault signal. This at least one switch thus not only possesses the corresponding switching functionality but also simultaneously constitutes the at least one control device. In other words, the at least one switch can also be understood as the at least one control device with a switching function. Such a switch can also be referred to as an intelligent switch or smart switch. Similarly, an intelligent fuse or so-called smart fuse can be used, which can implement switching functions. The at least one switch can incorporate a microprocessor to actively control these switching functions. Alternatively or additionally, hardware components can be integrated into the at least one switch that automatically react to operating states or fault conditions that require switching.The combination of a microprocessor and hardware components can, for example, be used to control switching according to the second type of fault signal via the microprocessor, while the hardware components are designed for switching when the first type of fault signal is present. Additionally, the switching function of at least one switch can be controlled via another control device for reasons of at least partial redundancy and / or to extend switching functionalities.

[0028] The switch can also be designed as a so-called brake chopper. A brake chopper, in this context, is a device that includes a switch capable of connecting an electric motor, particularly one used to drive an electric or hybrid vehicle, to at least one connecting cable. The electrical resistance unit is either part of the brake chopper or positioned between the electric motor and the brake chopper to allow energy to be drawn from or supplied to the at least one connecting cable via the brake chopper when connected. The dissipation of energy refers to the described energy loss in the event of a fault, as an energy outflow from the at least one connecting cable towards the electrical resistance unit.In cases not aimed at energy dissipation, but rather, for example, at charging the energy source, the connection can also be used for an energy supply line, for instance, to provide recuperation energy to the energy source and / or to operate at least one electronic device. The brake chopper and / or another switching device can also be configured to switch a connection between the electric motor and at least one connecting line and / or another connecting line to at least one energy source and / or at least one electronic device, bypassing the electrical resistance unit and thus enabling a bypass. In addition to the switch, the brake chopper can also include a control device and / or at least one detection device for voltage and / or current detection.

[0029] In one embodiment, the control device is configured to connect the at least one electrical resistor of the at least one electrical resistance unit to the at least one connecting line for a predetermined minimum period of time until the fault signal is cleared and / or a voltage level has dropped to a predetermined maximum amount.

[0030] The predetermined minimum period refers to the timeframe within which the reduction of a voltage from, for example, 800 V to 60 V is considered complete. The predetermined minimum period can be estimated differently depending on the operating state of the energy management system and / or the number of electronic loads to be supplied with electrical energy by the energy management system, or the associated range of functions. If, after the predetermined minimum period, the voltage level has not dropped to a predetermined maximum value, e.g., 60 V, or the fault signal has not cleared, the connection can be continued or re-established. The continued or re-established connection can then be scheduled again according to the predetermined minimum period or according to a reduced predetermined minimum period that is shorter than the initial predetermined minimum period.Accordingly, it is possible to perform an initial, rough voltage reduction over the predetermined minimum period, while a fine-tuning of the voltage reduction is achieved over the reduced predetermined voltage reduction period. In this configuration, it can also be stipulated that the initial predetermined minimum period is determined in such a way that the final minimum voltage level to be reached is not quite reached, for example, only 70 V. This prevents the voltage level of 60 V, which may still be required for other functions, from being undercut, either completely or only slightly.

[0031] As an alternative to estimating an initial and / or reduced predetermined minimum connection time for the at least one electrical resistor to the at least one connecting line, or estimating or controlling recurring connection cycles, the dissipation of electrical energy during the connection can also be monitored. Accordingly, the connection time is not based on predetermined time periods, but on essentially continuous detection. The term "essentially continuous" means that the detection or corresponding response time of a hardware component is shorter than a connection cycle that would otherwise be based on a predetermined time period.

[0032] In one embodiment, at least one energy source is a high-voltage energy source, in particular a traction battery.

[0033] A high-voltage power source is a power source capable of providing a voltage greater than 500 V, particularly 800 V or more. For example, a traction battery, also known as a drive battery, can be used as a high-voltage power source. In this case, at least one electronic load is preferably an electric motor.

[0034] In one embodiment, at least one energy source is a direct current source.

[0035] In particular, the energy source is designed as a high-voltage direct current source. The corresponding implementation can be carried out using the traction battery mentioned above as a high-voltage direct current source. In one embodiment, the at least one energy source supplies high-voltage energy to at least one first electronic load group, each with at least one electronic load, via at least one high-voltage connecting line, and supplies low-voltage energy to at least one second electronic load group, each with at least one electronic load, via a voltage converter, in particular a DC-to-V converter, and at least one low-voltage connecting line.

[0036] The above configuration thus makes it possible, for example, to supply both a first group of electronic loads, representing at least one electronic load for high-voltage energy, and a second group of electronic loads, representing at least one electronic load for low-voltage energy, with the required electrical energy via a high-voltage direct current source. The voltage converter used for the second group of electronic loads can, for example, convert a high voltage of 800 V into a low voltage of 48 V or 24 V. The voltage converter can be connected upstream of all electronic loads in the second group, or only to one electronic load or a subgroup of electronic loads, for example, if there are several electronic loads.Multiple voltage converters can also be provided, which can optionally differ from each other.

[0037] In particular, at least one electrical resistance unit can be connected to at least one high-voltage connecting line between at least one energy source and the voltage converter.

[0038] The electrical energy in the high-voltage connection line can then be adjusted via the at least one electrical resistance unit when the at least one electrical resistance unit is connected to the high-voltage connection line. In one embodiment, the voltage converter is connected to the at least one second electronic load group via the at least one low-voltage connection line, wherein the at least one electrical resistance unit, in particular the at least one electrical resistance of the at least one electrical resistance unit, can be connected to the at least one low-voltage connection line.

[0039] Thus, voltage reduction in the at least one low-voltage connection line can occur via the at least one electrical resistance unit or the at least one electrical resistor. Alternatively or additionally, the low-voltage connection line can be used to supply the at least one switch and / or the at least one control device with electrical energy.

[0040] According to a further aspect, the present invention relates to a method for operating an energy management system described above. The method comprises the following steps:

[0041] Supplying electrical energy from the at least one energy source to the at least one electronic load, wherein the at least one electronic load can be connected to the at least one energy source via at least one connecting line, and

[0042] Connecting the at least one electrical resistor of the at least one electrical resistance unit to the at least one connecting line when an error signal is present.

[0043] The procedure may include the detection of a fault. Alternatively or additionally, automatic connection may also occur, for example, due to hardware components installed in the control device or switch as described above. The features described in the description of the energy management system are equally applicable to the procedure. Likewise, features described for the procedure are transferable to the energy management system, provided they have not already been described for the energy management system.

[0044] According to another aspect, the present invention relates to a computer program product with code means configured to enable a control device to execute the method described above.

[0045] This allows vehicles to be retrofitted in a simple manner. For example, if detection devices for detecting quantities representing a fault are already provided, the computer program can initiate the reading of the data and its corresponding processing by at least one control device in order to connect the at least one electrical resistor as required, according to the aforementioned voltage reduction method.

[0046] Here too, it applies that features described for or applicable to the process can be transferred to the computer program product according to their applicability, and vice versa.

[0047] According to a further aspect, the present invention relates to a vehicle, in particular a commercial vehicle, which has a previously described energy management system, wherein the vehicle is in particular an electric vehicle or a hybrid vehicle.

[0048] Features described for or applicable to the energy management system are transferable to the vehicle according to their applicability, and vice versa.

[0049] Overall, the invention aims to provide an energy management system and its use for reducing a high voltage level to a safe low voltage level in the event of a fault or the disconnection of at least one electronic load. By utilizing at least one electrical resistor, the voltage reduction can be achieved via an existing functional component without requiring a separate device. For this purpose, for example, an electrical braking resistor already incorporated as a functional component can be used.

[0050] An exemplary embodiment of the present invention is described below with the aid of the accompanying drawing.

[0051] In detail, it shows

[0052] Fig. 1 shows a schematic representation of an exemplary embodiment of an energy management system to which the present invention is applicable.

[0053] Fig. 1 shows a schematic representation of an exemplary embodiment of an energy management system 1 to which the present invention is applicable. In the present embodiment, the energy management system 1 is installed in an electric vehicle (not shown). The energy management system 1 comprises a traction battery 10 as an energy source, which provides high-voltage energy of 800 V. The traction battery 10 is a direct current source. A high-voltage connecting line 80 extends from the traction battery 10 to connect an electric motor 60, a high-voltage auxiliary unit 52 (such as an air conditioning compressor, a compressed air compressor, or a heater / instantaneous water heater), and another high-voltage consumer 53 (such as a power steering pump or electric brakes) to the traction battery 10 for the provision of electrical energy.An inverter 51 is connected upstream of the electric motor 60 to convert the high-voltage direct current into three-phase alternating current. Conversely, in recuperation mode, the three-phase alternating current of the electric motor 10 can be converted into direct current to charge the traction battery 10. The electric motor 60, the high-voltage auxiliary unit 52, and the additional high-voltage consumer 53 represent a first electronic consumer group. Additionally, an electrical braking resistor unit, designated as an electrical resistance unit 20, is connected to the high-voltage connecting line 80. The connection point of the electrical resistance unit 20 to the high-voltage connecting line 80 is located between the traction battery 10 and the first electronic consumer group 52, 53, 60.The electrical resistance unit 20 includes an electrical braking resistor, designated as electrical resistor 20a, which can be connected to the high-voltage connecting line 80 via a switch 22. In the exemplary embodiment, the electrical resistance unit 20 is connected to a switchable auxiliary battery 23 as a switchable auxiliary power source, which can alternatively and / or additionally be connected to the high-voltage connecting line 80 via the switch 22. In an alternative embodiment, the switchable auxiliary battery 23 can also be included by the electrical resistance unit, either alternatively or additionally.

[0054] Furthermore, a DC / DC converter 30 is connected to the traction battery 10 via the high-voltage connecting line 80 and converts the high voltage of the traction battery 10 (800 V) into a low voltage of 48 V or 24 V. The DC / DC converter 30 is connected via a low-voltage connecting line 90, for example, to an electric power steering unit 41, an electromechanical brake unit 42, and another low-voltage auxiliary unit 43, such as a control unit, sensors, pumps, a windshield wiper, a seat heater, or an infotainment system. The electric power steering unit 41, the electromechanical brake unit 42, and the other low-voltage auxiliary unit 43 represent a second group of electronic consumers.Between the DC-DC converter 30 and the second electronic load group 41, 42, 43, the low-voltage connecting line 90 branches off to the switch 22 of the electrical resistance unit 20, in order to be connected via the switch 22 to the electrical resistor 20a of the electrical resistance unit 20. In Fig. 1, the low-voltage connecting line 90 and its respective connections are shown by dashed lines, and the high-voltage connecting line 80 and its respective connections are represented by solid lines. Dotted lines indicate control connections, which will be discussed below.

[0055] The control connections relate to the actuation of the switch 22 via an internal control device 21 of the electrical resistance unit 20 and via an external control device 70. In alternative embodiments, only the internal control device 21 or the external control device 70 may be provided for actuating the switch 22. In a further alternative or alternative addition, the switch 22 itself may have a control device. The high-voltage connection line 80 and / or the low-voltage connection line 90 can be selectively connected to and disconnected from the electrical resistance 20a of the electrical resistance unit 20 via the switch 22. In the present embodiment, this is done via one and the same switch 22, which allows different connection configurations in different switching positions, i.e., has more than two switching positions.In an alternative embodiment, the following can also be used:

[0056] Different switches can be used for the high-voltage connection line 80 and the low-voltage connection line 90 to enable selective switching. Alternatively, only the high-voltage connection line 80 or the low-voltage connection line 90 can be provided for connection to the electrical resistor via switch 22.

[0057] In the present exemplary embodiment, the internal control device 21 of the electrical resistance unit 20 stores at least one fault condition or fault signal value for each predetermined operating mode, in which the switch 22 is to be connected to the electrical braking resistor with the high-voltage connection line 80 and / or the low-voltage connection line 90 for the first and second electronic load groups. The external control device 70 stores at least one further fault condition or fault signal value for each predetermined operating mode, in which the switch 22 is to be connected to the electrical resistance with the high-voltage connection line 80 and / or the low-voltage connection line 90. Here, the fault condition or fault signal value relates to...the fault signal value with respect to the internal control device 21 is a fault signal with respect to the second electronic consumer group 41, 42, 43 and the further fault condition or the fault signal value with respect to the external control device 70 is a fault signal with respect to the first electronic consumer group 52, 53, 60.

[0058] Based on the energy management system 1 described above, the functionality of the energy management system 1 without the occurrence of an error signal will now be described.

[0059] During a journey of a vehicle with the energy management system 1, at constant or increasing speed, as a first exemplary operating mode, the electrical resistor 20a of the electrical resistance unit 20 is not connected to the high-voltage connecting line 80 and the low-voltage connecting line 90 via the switch 22. Electrical energy is supplied to the respective electronic consumer 41, 42, 43, 52, 53, 60 as needed from the traction battery 10, according to its membership in the first or second electronic consumer group, in the form of high-voltage direct current or low-voltage direct current or alternating current.

[0060] In the event of braking using the electric motor 60 in recuperation mode as a regenerative brake (as an exemplary second operating mode), the traction battery 10 is recharged. If the traction battery 10 cannot be recharged further or the electrical energy cannot be used otherwise, the switch 22 is moved to a position in which it connects the electrical resistor 20a of the electrical resistance unit 20 to the high-voltage connecting line 80. This allows the electrical braking resistor to act as an additional load, converting and dissipating the energy used for voltage reduction into heat. In an alternative embodiment, a different switch and / or a separate connection between the electric motor 60 and the electrical resistor 20a can be provided for this purpose.

[0061] If the vehicle is involved in an accident while in the first operating mode, and this accident is detected by an airbag deployment via a respective detection device (not shown), a corresponding error signal is transmitted to the external control device 70. This results in the following control of switch 22.

[0062] The external control device 70 actuates the switch 22 to connect the electrical resistor 20a of the electrical resistance unit 20 to the high-voltage connecting line 80. The connection is disconnected again via the switch 22 after a predetermined minimum period. The connection for the predetermined minimum period is intended to maintain the voltage of 800

[0063] The voltage is reduced to 60 V. If the voltage is still above 60 V after the connection is broken, the connection cycle is repeated until the voltage level reaches 60 V. The duration of the connection in these repeated connection cycles is continuously reduced to ensure a significant drop below 60 V.

[0064] To avoid V.

[0065] This procedure can be applied similarly to a fault signal detected by the internal control device 21, whereby in this case the internal control device 21 actuates the switch 22 to connect the electrical resistance 20a of the electrical resistance unit 20 to the high-voltage connection line 80 and / or low-voltage connection line 90, depending on the fault signal. With regard to the fault signal associated with the second consumer group 41, 42, 43, it may be sufficient to connect only the low-voltage connection line 90 to the electrical resistance 20a to achieve the required voltage reduction.

[0066] In general, regardless of whether the switch 22 is controlled by the internal control device 21 and / or the external control device 70, a targeted response to a fault signal representing the need for voltage reduction can be achieved by selectively connecting the electrical resistor 20a to the high-voltage connection line 80 and / or the low-voltage connection line 90. For example, if a fault signal requiring a response occurs only with respect to the first consumer group 52, 53, 60 connected to the high-voltage connection line 80, it may be advantageous to connect only the high-voltage connection line 80 to the electrical resistor 20a in order to avoid or at least limit interaction with the second consumer group 41, 42, 43.

[0067] In the second operating mode, i.e., the recuperation mode of the electric motor 60, a distinction must be made between two cases. In the first case, the energy generated by the electric motor 60 can be absorbed by the traction battery 10. During the charging of the traction battery 10, the electrical resistor 20a is therefore not connected to the high-voltage connecting line 80 in order to convert and dissipate excess electrical energy as heat. If an error signal occurs in this configuration that requires a voltage reduction, the energy management system 1 reacts as already described for the first operating mode.

[0068] In a second case, the electric motor 60 provides excess electrical energy that can no longer be absorbed by the traction battery 10 or otherwise utilized. Therefore, in this second case, the electrical resistor 20a, in consideration of its original function, is already connected to the high-voltage connection line 80 via the switch 22. If a fault signal occurs that requires a voltage reduction, the electrical resistor is additionally connected to the low-voltage connection line 90 via the switch 22. In the embodiment described above, when a fault signal requiring a voltage reduction occurs, the voltage is reduced by connecting the electrical resistor 20a to the high-voltage connection line 80 and / or the low-voltage connection line 90 as described above. The electrical resistor 20a then acts as an additional load.If the voltage reduction is intended to occur only to the extent that a predetermined voltage level, such as the 60 V specified in the embodiment, is to remain available, the switchable auxiliary battery 23 is connected to the high-voltage connection line 80 via the switch 22 of the electrical resistance unit 20 when the voltage falls below 60 V due to the previous connection. The auxiliary battery 23 can then introduce electrical energy directly, or in other embodiments via the electrical resistor 20a, into the high-voltage connection line 80 and / or the low-voltage connection line 90 to compensate for the deficit. In an alternative embodiment, the switchable auxiliary battery 23 is preferably part of the electrical resistance unit 20, in which case the auxiliary battery 23 is connected instead of the electrical resistor to avoid losses across the electrical resistor.However, if the supply of electrical energy from the switchable auxiliary battery 23 is used via the electrical resistance, it is possible to throttle the energy supply in order to control the compensation of deficits more precisely.

[0069] The invention is not limited to the described embodiment. In particular, features described for this embodiment, as well as for other described embodiments and further developments of the invention, can be combined with one another, provided they are not mutually exclusive. For example, the description of the above embodiment relates to a voltage reduction in the event of a fault signal indicating an accident or malfunction. In other embodiments, the principle can also be applied alternatively or additionally to a fault signal that signals an intended disconnection of at least one electronic load. Furthermore, the above embodiment is described with regard to a first and second load group, or high-voltage and low-voltage loads.However, the control of the connection of the electrical resistor with at least one connecting line can also be directed only at an error signal from high-voltage consumers, since otherwise the safety risk is particularly high.

[0070] REFERENCE MARK LIST

[0071] 1 Energy management system

[0072] 10 Traction battery (energy source) 20 Electrical resistance unit

[0073] 20a electrical resistance

[0074] 21 ECU (internal control unit)

[0075] 22 switches

[0076] 30 DC / DC converters (voltage converters) 41 electric steering unit

[0077] 42 electromechanical brake (brake unit)

[0078] 43 Low-voltage auxiliary units

[0079] 51 inverters

[0080] 52 High-voltage auxiliary equipment 53 High-voltage consumers

[0081] 60 electric motor

[0082] 70 external control device

[0083] 80 High-voltage connecting line (connecting line)

[0084] 90 Low-voltage connecting cable (connecting cable)

Claims

PATENT CLAIMS 1. Energy management system (1) for a vehicle, comprising: at least one electronic consumer (41, 42, 43, 52, 53, 60) for providing a vehicle function, at least one energy source (10) for supplying the at least one electronic consumer (41, 42, 43, 52, 53, 60) with electrical energy, wherein the at least one electronic consumer (41, 42, 43, 52, 53, 60) is connectable to the at least one energy source (10) via at least one connecting line (80, 90), at least one electrical resistance unit (20) comprising at least one electrical resistance (20a), wherein the at least one electrical resistance (20a) is connectable to the at least one connecting line (80, 90), and at least one control device (21, 70) configured to control the at least one electrical resistance (20a) of the at least one electrical resistance unit (20) to connect to at least one connecting line (80, 90),when an error signal is present.

2. Energy management system (1) according to claim 1, wherein the at least one electrical resistance unit (20) has at least one electrical Braking resistance unit with at least one electrical braking resistance as the at least one electrical resistance (20a).

3. Energy management system (1) according to claim 1 or 2, wherein the fault signal is representative of a vehicle accident, a malfunction of a component of the energy management system (1) and / or a fault that can be influenced by the energy management system (1).

4. Energy management system (1) according to one of the preceding claims, wherein the at least one control device (21, 70) is an internal control device (21) of the at least one electrical resistance unit (20) or an external control device (70) of the energy management system (1), which is connected to the at least one electrical resistance unit (20) and / or at least one connecting line (80, 90) is connected.

5. Energy management system (1) according to one of the preceding claims, wherein the at least one control device (21, 70) controls at least one switch (22) or has at least one switch (22) to connect or disconnect the at least one electrical resistor (20a) from the at least one connecting line (80, 90).

6. Energy management system (1) according to claim 5, wherein the at least one switch (22) is configured to switch independently depending on the fault signal.

7. Energy management system (1) according to one of the preceding claims, wherein the control device (21, 70) is configured to connect the at least one electrical resistance (20a) of the at least one electrical resistance unit (20) to the at least one connecting line (80, 90) for a predetermined minimum period of time until the fault signal is cleared and / or a voltage level has dropped to a predetermined maximum amount.

8. Energy management system (1) according to one of the preceding claims, wherein the at least one energy source (10) is a high-voltage energy source, in particular a traction battery.

9. Energy management system (1) according to any of the preceding claims, wherein the at least one energy source (10) is a direct current source.

10. Energy management system (1) according to claim 8 or 9, wherein the at least one energy source (10) supplies high-voltage energy to at least one first electronic consumer group (52, 53, 60) with at least one electronic consumer (52, 53, 60) via at least one high-voltage connecting line (80) as a connecting line and supplies at least one second electronic consumer group (41, 42, 43) with at least one electronic consumer (41 , 42, 43) is supplied with low-voltage energy via a voltage converter (30), in particular a DC voltage converter, via at least one low-voltage connecting line (90) as a connecting line.

11. Energy management system (1) according to claim 10, wherein the at least one electrical resistance unit (20) is arranged in the at least one high-voltage connecting line (80) between the at least one energy source (10) and the voltage converter (30).

12. Energy management system (1) according to claim 10 or 11, wherein the voltage converter (30) is connected to the at least one second electronic consumer group (41, 42, 43) via the at least one low-voltage connecting line (90), wherein the at least one electrical resistance unit (20), in particular the at least one electrical resistance (20a) of the at least one electrical resistance unit (20), is connectable to the at least one low-voltage connecting line (90).

13. Method for operating an energy management system (1) according to any of the preceding claims, comprising the following steps: Supply of electrical energy from the at least one energy source (10) to the at least one electronic load (41, 42, 43, 52, 53, 60), wherein the at least one electronic load (41, 42, 43, 52, 53, 60) can be connected to the at least one energy source (10) via at least one connecting line (80, 90), and Connecting the at least one electrical resistor (20a) of the at least one electrical resistance unit (20) to the at least one connecting line (80, 90) when an error signal is present. 14: Computer program product with code means configured to cause a control device (21, 70) to execute the method according to claim 13.

15. Vehicle, in particular commercial vehicle, comprising an energy management system according to any one of claims 1 to 12, wherein the vehicle is in particular an electric vehicle or a hybrid vehicle.

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