Energy management system for a vehicle

Abstract

The present 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 electrical energy to the at least one electronic load (41, 42, 43, 52, 53, 60), the at least one electronic load (41, 42, 43, 52, 53, 60) being connectible via at least one connecting line (80, 90) to the at least one energy source (10), at least one electrical resistance unit (20) having at least one electrical resistor (20a), the at least one electrical resistor (20a) being connectible to the at least one electronic load (41, 42, 43, 52, 53, 60) via at least one connecting line (80, 90), and at least one control device (21, 70) configured to connect the at least one electrical braking resistor of the at least one electrical braking resistor unit (20) to the at least one connecting line (80, 90) when an electrical energy that can be assigned to the at least one energy source (10), to the at least one connecting line (80, 90) and / or to the at least one electronic load (41, 42, 43, 52, 53, 60) deviates from a setpoint value by at least a first predetermined amount and / or by at least a second predetermined amount for at least a predetermined time, the second predetermined amount being equal to the first predetermined amount or being different from the first predetermined amount.

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 connecting cable leading from an energy source such as a traction battery. This cable supplies power to components like a traction motor, including inverters and / or high-voltage compressors. To prevent or compensate for under- and overvoltages, an active voltage control system can be implemented for this connecting cable. This system includes, for example, a control element, a voltage regulator, and a booster element to adjust the voltage level, minimizing the operating voltage range and thus compensating for under- and overvoltages. Otherwise, voltage fluctuations in the connecting cable, which can cause, among other things,Fluctuations in energy consumption or energy supply from consumers connected via the connecting line may impair driving comfort.

[0005] Besides the impairment of driving comfort, such as the negative impact of voltage fluctuations on the powertrain, components in or on the connecting cable can also be affected by voltage fluctuations. For example, voltage fluctuations can lead to increased energy losses and a reduced lifespan for voltage converters and / or inverters connected to the cable.

[0006] The object of the present invention is to provide an energy management system and a corresponding application that can reduce voltage fluctuations. This object is achieved by the subject matter of the dependent claims.

[0007] Beneficial further training is subject to dependent claims.

[0008] 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 can be connected to the at least one energy source via at least one connecting line, and at least one electrical resistance unit, which has at least one electrical resistance, wherein the at least one electrical resistance can be connected to the at least one connecting line.Furthermore, the energy management system includes 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 the electrical energy attributable to the at least one energy source, the at least one connecting line and / or the at least one electronic consumer deviates from a setpoint by at least a first predetermined amount and / or over at least a predetermined time by at least a second predetermined amount, which is equal to or differs from the first predetermined amount.

[0009] An electronic component used to provide a vehicle function can be, for example, an electric power steering unit to assist manual steering and / or to perform a steering function autonomously. It can also be a braking unit, such as an electromechanical brake, to perform a braking function and / or an electric motor to perform a propulsion function. Further examples of electronic components include climate control units, navigation systems, and vehicle lighting systems. Generally, an electronic component is understood here as a unit that is powered by electrical energy to perform at least one predetermined function.The term "consumer" does not exclude the possibility that a consumer is a component or unit that not only requires electrical energy to perform a function, but can also provide and / or transmit electrical energy.

[0010] 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.

[0011] According to the invention, at least one electrical resistance unit is provided to be connected to at least one connecting line in order to be able to dissipate excess energy via the electrical resistance or to convert it into heat.

[0012] The foregoing function is implemented via the at least one control device which is configured accordingly to connect the at least one electrical resistance of the at least one electrical resistance unit to the at least one connecting line when the electrical energy attributable to the at least one energy source, the at least one connecting line and / or the at least one electronic load deviates from a setpoint by at least a first predetermined amount and / or over at least a predetermined time by at least a second predetermined amount, which is equal to or differs from the first predetermined amount.

[0013] Consequently, during energy fluctuations, the electrical resistance can be selectively connected to the at least one connecting line via the control device, for example, to dissipate electrical energy across the electrical resistance. The electrical energy can then be converted into heat and dissipated via the at least one electrical resistance. This applies to fluctuations where the amount of electrical energy is too high. Conversely, even during fluctuations where the amount of electrical energy is too low, energy can be supplied via the at least one electrical resistance unit and / or across the at least one electrical resistance unit.This applies, for example, to a configuration in which the at least one electrical resistance unit has or is connected to an additional energy source, from which electrical energy can be supplied to the energy source and / or the at least one electrical load via the at least one connecting line, possibly also via the at least one electrical resistance. The at least one electrical resistance can alternatively or additionally provide heat energy that can be used by other loads.

[0014] The fluctuations to be compensated here relate to deviations of the electrical energy from a setpoint by at least a predetermined amount. The first predetermined amount can, for example, be directed at exceeding a tolerable maximum deviation from the setpoint in order to avoid the risk of damage. Alternatively or additionally, a second predetermined amount can be provided to trigger a connection between at least one connecting line and at least one electrical resistor, taking a time criterion into account. In this case, a connection is not triggered by a single deviation, but by a continuous deviation or a deviation occurring with a certain frequency over the predetermined time by the second predetermined amount.For example, in a combination of the first and second predetermined amounts, the first predetermined amount may be higher than the second. In such a case, the control device can then execute the connection if a critical maximum deviation from the setpoint associated with the first predetermined amount, or a critical deviation from the setpoint associated with the second predetermined amount according to a time criterion, is exceeded. The first and / or second predetermined amount may be adjustable and, for example, changed depending on an operating mode. Similarly, the voltage level of a high-voltage line used as a connection line may be smoothed or otherwise influenced so that connected components and loads can also be protected.This can therefore also involve smoothing or otherwise influencing at least one energy source in order to protect components such as a DC-DC converter. With regard to the example energy source as the cause of fluctuations, a portion of the energy can thus be dissipated via the electrical resistance, which could otherwise, upon reaching other components, lead to a risk of damage or a reduction in lifespan.

[0015] The connecting line intended for the connection can be designed as a cable or as part of a bus system. The connecting line does not necessarily have to be continuously flexible like a cable, but can also be rigid, at least in sections. In this context, a plug connector can also be considered a connecting line.

[0016] In one embodiment, the at least one electrical resistance unit is at least one electrical braking resistance unit with at least one electrical braking resistance as the at least one electrical resistance.

[0017] The at least one electrical braking resistor unit, for example in electric or hybrid vehicles, can be assigned to a regenerative brake, 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, into heat via the electrical braking resistor during conventional operation. In the context of the present invention, the function of the at least one electrical braking resistor unit is extended to include the functionality of compensating for fluctuations in electrical energy. Accordingly, the at least one electrical braking resistor unit can thus be considered an additional consumer unit in addition to 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. 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, unless the description is specifically directed at braking resistor-specific functionalities. Conversely, functionalities of the electrical resistor unit or the electrical resistor itself are also analogous to the electrical braking resistor unit or a general electrical resistor.the electrical braking resistance is transferable.

[0018] In one embodiment, at least one control device measures the amount of the deviation according to a voltage and / or a current.

[0019] In this context, the term "measured" refers to the control device's ability to react to the first and / or second predetermined value. For this purpose, the control device may have corresponding signal inputs through which a detection signal from a voltage and / or current detection device is transmitted to the control device. Alternatively or additionally, the control device may itself include such a detection device. In particular, the control device has a corresponding signal processing unit to determine a deviation, but it may also, alternatively or additionally, simply implement signals that have already been processed accordingly.Alternatively or additionally, the control device can perform passive control of the connection by hardware components that automatically execute switching operations depending on an applied voltage and / or current.

[0020] In one embodiment, the at least one control device is either 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. In the case of the at least one control device being an internal control device of the at least one electrical resistance unit, an existing energy management system can be easily retrofitted without having to modify an external control device.In the case of at least one control device acting as an external control device for the energy management system, where "external" is to be understood in relation to "internal" (i.e., not integrated into the at least one electrical resistance unit), the reverse advantage of adapting the energy management system without modifying the at least one electrical resistance unit can arise. Ultimately, however, both at least one internal and at least one external control device can be provided, which are at least partially redundant to each other or complement each other in their control. Complementary control, for example, involves the internal control device responding to the first predetermined deviation from the setpoint, while the external control device responds to the second predetermined deviation from the setpoint.

[0021] 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.

[0022] 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.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.

[0023] The term "switch" generally encompasses components that can perform a corresponding switching function via a control system and / or corresponding hardware components.

[0024] In particular, at least one switch is configured to switch independently depending on the deviation of the electrical energy by at least the first and / or second predetermined amount.

[0025] The 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 switching functions. Alternatively or additionally, hardware components can be integrated into the at least one switch that automatically react to operating states requiring switching.The combination of a microprocessor and hardware components can, for example, be used to control switching via the microprocessor based on the second predetermined deviation from the setpoint, while the hardware components are designed to switch when the first predetermined deviation from the setpoint is exceeded. Additionally, for reasons of at least partial redundancy and / or to extend switching functionalities, the switching function of at least one switch can be controlled via another control device.

[0026] 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 energy dissipation refers to the described reduction of fluctuations, which is an energy outflow from the at least one connecting cable towards the electrical resistance unit.In cases not aimed at reducing fluctuations, but for example for charging the energy source, the connection can also be used for an energy supply line, for example to provide recuperation energy to the energy source and / or to operate at least one electronic load. 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 load, 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.

[0027] In one embodiment, the control device is configured to connect and disconnect the at least one electrical resistance of the at least one electrical resistance unit with the at least one connecting line for a predetermined period of time, in particular to repeat the connection and disconnection until the electrical energy attributable to the at least one energy source, the at least one connecting line and / or the at least one electronic consumer has reached the setpoint or deviates only by a third predetermined amount, which is smaller than the first predetermined amount and / or the second predetermined amount.

[0028] The compensation of fluctuations typically involves balancing limited deviations from the setpoint. In other words, compensation is provided within the range of an operating level, i.e., within a level of electrical energy required for operation to supply at least one load with electrical energy. Accordingly, the connection of at least one electrical braking resistor to at least one connecting line for the purpose of fluctuation compensation is not usually intended to be permanent. For this purpose, a predetermined period can be defined, for example, during which the at least one electrical resistor is connected to the at least one connecting line and then disconnected again. The predetermined period can be set, for example, such that a dissipation of a certain amount of electrical energy through the at least one electrical resistor is expected within this predetermined period.To prevent a reduction in electrical energy that would impede the adequate supply of at least one electronic device, the predetermined period can be set in such a way that it is not aimed at a complete reduction of the deviation, but rather occurs in several small steps, i.e., over several predetermined periods. The predetermined period can be adjusted to the magnitude of the deviation from the target value, particularly the deviation from the target value at different times.

[0029] The connecting and disconnecting process is repeated, in particular, until the electrical energy attributable to the at least one energy source, the at least one connecting line, and / or the at least one electronic load reaches the target value. This can be estimated based on a deviation value by determining the required number of connection cycles and / or monitored or controlled by appropriate detection devices. Alternatively, it may be possible not to apply the above procedure to the target value, but simply to repeat the connection cycles until the deviation, according to a third predetermined value, is within a tolerable deviation range.

[0030] As an alternative to estimating a predetermined time period required once for connecting at least one electrical resistor to 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 required according to a predetermined time period.

[0031] In one embodiment, at least one energy source is a high-voltage energy source, in particular a traction battery.

[0032] 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.

[0033] In one embodiment, at least one energy source is a direct current source.

[0034] In particular, the energy source is designed as a high-voltage direct current source. The corresponding implementation can be achieved by using the aforementioned traction battery as a high-voltage direct current source.

[0035] In particular, the at least one energy source supplies high-voltage energy to at least one first electronic consumer group with at least one electronic consumer via at least one high-voltage connecting line and supplies low-voltage energy to at least one second electronic consumer group with at least one electronic consumer via a voltage converter, in particular a DC voltage converter, via 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] According to an advantageous further development, the at least one electrical resistance unit can be connected to the at least one high-voltage connecting line between the at least one energy source and the voltage converter.

[0038] The electrical energy in the high-voltage connecting line can then be adjusted via the at least one electrical resistance unit when the at least one electrical resistance is connected to the high-voltage connecting line.

[0039] In particular, the voltage converter is connected to the at least one second electronic consumer group via the at least one low-voltage connecting 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, is connectable to the at least one low-voltage connecting line.

[0040] Thus, fluctuations in the at least one low-voltage connection line can also be compensated for 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.

[0041] 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:

[0042] Supply of electrical energy from the at least one energy source to the at least one electronic load, 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),

[0043] Connecting the at least one electrical resistance of the at least one electrical resistance unit to the at least one electronic load, if the electrical energy attributable to the at least one energy source, the at least one connecting line and / or the at least one electronic load deviates from a setpoint by at least a first predetermined amount and / or over at least a predetermined time by at least a second predetermined amount, which is equal to or differs from the first predetermined amount.

[0044] The procedure can include detecting deviations from the setpoint. Alternatively or additionally, automatic connection can also occur, triggered, for example, by hardware components installed in the control device or switch as described above. Deviations from the setpoint can also be represented by event signals. For example, such event signals relate to a specific operating mode and / or specific operating parameters in which fluctuations typically occur that exceed the first and / or second predetermined value. Under such operating conditions, the electrical resistance can then be activated prophylactically.

[0045] The characteristics described in the description of the energy management system are equally applicable to the process. Likewise, characteristics described for the process are transferable to the energy management system, provided they have not already been described for the energy management system.

[0046] 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.

[0047] This allows vehicles to be easily retrofitted. For example, if detection devices for detecting quantities representing electrical energy 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 according to the aforementioned method for compensating fluctuations in electrical energy as required.

[0048] 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.

[0049] 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.

[0050] Features described for or applicable to the energy management system are transferable to the vehicle according to their applicability, and vice versa. Overall, the invention aims to provide an energy management system and its use for compensating fluctuations in the electrical energy available to at least one consumer, in particular to smooth the voltage level of the at least one energy source. By utilizing the at least one electrical resistor, the compensation can be achieved via an existing functional component without requiring a separate device. For example, an electrical braking resistor already provided as a functional component can be used for this purpose.

[0051] An exemplary embodiment of the present invention is described below with the aid of the accompanying drawing.

[0052] In detail, it shows

[0053] Fig. 1 shows a schematic representation of an exemplary embodiment of an energy management system to which the present invention is applicable.

[0054] 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 a three-phase alternating current. Conversely, in recuperation mode, the three-phase alternating current of the electric motor 60 can be converted into direct current to charge the traction battery 10. The electric motor 60, the...

[0055] The high-voltage auxiliary unit 52 and the further high-voltage consumer 53 represent a first electronic consumer group.

[0056] Additionally, an electrical braking resistor unit, designated as electrical resistance unit 20, is connected to the high-voltage connection line 80. The connection point of the electrical resistance unit 20 to the high-voltage connection 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 connection 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 energy source, which can alternatively and / or additionally be connected to the high-voltage connection line 80 via the switch 22.In an alternative embodiment, the switchable auxiliary battery 23 can alternatively or additionally be included by the electrical resistance unit as a switchable auxiliary energy source.

[0057] 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 voltage converter 30 and the second electronic consumer 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 able to be connected via the switch 22 to the electrical resistance 20a of the electrical resistance unit 20.

[0058] In Fig. 1, the low-voltage connection line 90 with its respective connections is shown by dashed lines, and the high-voltage connection line 80 with its respective connections is represented by solid lines. Dotted lines indicate control connections, which will be discussed below.

[0059] 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., it has more than two switching positions.In an alternative embodiment, different switches can be used for the high-voltage connecting line 80 and the low-voltage connecting line 90 to enable selective switching. In a further alternative, only the high-voltage connecting line 80 or the low-voltage connecting line 90 can be provided for connection to the electrical resistor via the switch 22.

[0060] In the present exemplary embodiment, the internal control device 21 of the electrical resistance unit 20 stores a respective setpoint of the direct current for a respective predetermined operating mode and a respective first predetermined amount for a deviation of the actual direct current from the respective setpoint, from the point at which the switch 22 is to be connected to the electrical resistance to the high-voltage connecting line 80 and / or the low-voltage connecting line 90 for the first and second electronic consumer group.The external control device 70 stores a setpoint value for the direct current for each predetermined operating mode and a second predetermined value for any deviation of the actual direct current from the respective setpoint. Upon reaching or exceeding this second predetermined value for at least a predetermined time, the switch 22 is to be closed to connect the electrical resistor to the high-voltage connection line 80 and / or the low-voltage connection line 90. In an alternative embodiment, different setpoint values ​​and different first and / or second predetermined values ​​for the high-voltage connection line 80 and the low-voltage connection line 90 can also be stored and used to control the switch 22.The first and / or second predetermined amount can also be adjustable, for example, to allow only smaller deviations after a certain operating time of components. In the present embodiment, the limit values ​​and the determination of actual values ​​essentially relate to monitoring fluctuations in the voltage level of the traction battery 10 in order to smooth the voltage level of the traction battery 10 by controlling the switch 22 and thus connecting the electrical resistor 20a. This primarily concerns the connection of the electrical resistor 20a to the high-voltage connecting line 80. Controlling the switch 22 for the corresponding connection to the electrical resistor 20a via the low-voltage connecting line 90 can be used additionally, for example, to accelerate the voltage reduction.

[0061] Based on the energy management system 1 described above, the operation of the energy management system 1 without fluctuations will now be described. 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 consumers 41, 42, 43, 52, 53, 60 as needed from the traction battery 10, according to their membership in the first or second electrical consumer group, in the form of high-voltage direct current or low-voltage direct current or alternating current.

[0062] 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 effectively, the switch 22 is moved to a position in which it connects the electrical resistance of the electrical resistance unit 20 to the high-voltage connecting line 80. This allows the electrical resistance 20a to act as an additional load, converting and dissipating the excess energy as heat. In an alternative embodiment, a different switch and / or a separate connection between the electric motor 60 and the electrical resistance 20a can be provided for this purpose.

[0063] If, in the first operating mode, a fluctuation occurs, for example, a voltage and / or current deviation from a respective setpoint for the first and / or second electronic load group, which is detected by a respective detection device (not shown) on a respective electronic load 41, 42, 43, 52, 53, 60, in the high-voltage connecting line 80 and / or in the low-voltage connecting line 90 and transmitted to the internal control device 21 and the external control device 70, the following control of the switch 22 results. If a deviation of the first predetermined amount or more with respect to the high-voltage connecting line 80 occurs, the internal control device 21 controls the switch 22 to connect the electrical braking resistor of the electrical braking resistor unit 20 to the high-voltage connecting line 80.The connection is disconnected again after a predetermined time via switch 22. If the setpoint or a third amount as a tolerable deviation from the setpoint has not yet been reached, the connection cycle is repeated until the setpoint or the third amount is reached. This procedure is similarly applicable to a deviation of the first predetermined amount or more with respect to the low-voltage connection line 90, wherein in this case the internal control device 21 actuates switch 22 to connect the electrical braking resistor of the electrical braking resistor unit 20 to the low-voltage connection line 90.If a deviation exists for both the high-voltage power connection line 80 and the low-voltage power connection line 90, the internal control device 21 controls the switch 22 such that the switch 22 connects the electrical resistance 20a of the electrical resistance unit 20 to both the high-voltage connection line 80 and the low-voltage connection line 90.In such a case, it may also be sufficient to connect the electrical braking resistor of the electrical braking resistor unit 20 only to the high-voltage connection line 80 in order to evaluate the effect of the compensation with respect to the connection of the electrical resistance 20a of the electrical resistance unit 20 to the high-voltage connection line 80 and only subsequently provide the connection of the electrical resistance 20a of the electrical braking resistor unit 20 to the low-voltage connection line 90 if the fluctuation cannot be compensated via the high-voltage connection line 80 within a predetermined number of connection cycles and / or over a predetermined time. Conversely, especially with only small compensation amounts, initially only the connection of the electrical resistance 20a of the electrical resistance unit 20 to the low-voltage connection line 90 may be provided.Analogous to the procedure regarding a deviation of the first predetermined amount or more, the external control device 70 activates the switch 22 if the current and / or voltage deviates by the second predetermined amount or more over a predetermined period and / or with a predetermined frequency within the predetermined period. Here too, in the first operating mode, the switch 22 is activated in such a case such that the electrical resistor 20a is connected to the high-voltage connecting line 80 and / or the low-voltage connecting line 90.As described above for the control of switch 22 by the internal control unit 21, the selective switching on of the electrical resistance 20a with respect to the high-voltage connection line 80 and / or the low-voltage connection line 90 takes place depending on the local occurrence of the current and / or voltage deviation and / or with regard to a prioritization. Here too, connection cycles are repeated until the respective setpoint is reached or the deviation is within a tolerable range according to a third predetermined amount.

[0064] In general, regardless of whether the switch 22 is controlled by the internal control device 21 and / or the external control device 70, fluctuations can be addressed 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 fluctuation requiring a response occurs only with respect to, or with effects to be considered on, the second consumer group 41, 2, 43 connected to the low-voltage connection line 90, it may be advantageous to connect only the low-voltage connection line 90 to the electrical braking resistor in order to avoid or at least limit interaction with the first consumer group 52, 53, 60.

[0065] 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 fluctuations occur in this configuration according to the first and / or second predetermined amount, the energy management system 1 reacts as already described for the first operating mode.

[0066] 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, considering its original function, is already connected to the high-voltage connection line 80 via the switch 22. If fluctuations occur according to the first and / or second predetermined value, the electrical resistor 20a is additionally connected to the low-voltage connection line 90 via the switch 22. Advantageously, at least the first or the second predetermined value is adjusted to a smaller value to allow for a faster response.

[0067] In the embodiment described above, deviations involving an exceedance of an upper limit according to the first and / or second predetermined amount are compensated by connecting the electrical resistor 20a to the high-voltage connecting line 80 and / or the low-voltage connecting line 90. The electrical resistor 20a then acts as an additional load. In the case of deviations involving a fall below a lower limit according to the first and / or second predetermined amount, the switchable auxiliary battery 23 is connected to the high-voltage connecting line 80 via the switch 22 of the electrical resistor unit 20, so that electrical energy can be introduced into the high-voltage connecting line 80 via the electrical resistor unit 20 to compensate for a deficit.In an alternative embodiment, the switchable auxiliary battery 23 can also be connected to the low-voltage connecting line 90. In alternative embodiments, however, the supply of electrical energy from the switchable auxiliary battery 23 can also be effected via the electrical resistor 20a. This can be used to throttle the energy supply in order to control the compensation of deficits more precisely. 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 reasonably mutually exclusive. For example, the description of the preceding embodiment is directed towards the reduction of electrical energy.The aforementioned energy management system can also be used to compensate for fluctuations that might result in an insufficient supply of electrical energy to at least one electronic device. This is possible if the electrical resistance unit has an auxiliary power source and / or is connected to an auxiliary power source that can supply energy to at least one electronic device when appropriately switched on.

[0068] REFERENCE MARK LIST

[0069] 1 Energy management system

[0070] 10 Traction battery (energy source)

[0071] 20 electrical resistance units

[0072] 20a electrical resistance

[0073] 21 ECU (internal control unit)

[0074] 22 switches

[0075] 23 Additional battery (additional power source)

[0076] 30 DC / DC converters (voltage converters)

[0077] 41 electric steering unit

[0078] 42 electromechanical brake (brake unit)

[0079] 43 Low-voltage auxiliary units

[0080] 51 inverters

[0081] 52 high-voltage auxiliary units

[0082] 53 high-voltage consumers

[0083] 60 electric motor

[0084] 70 external control device

[0085] 80 High-voltage connecting line (connecting line)

[0086] 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),if the electrical energy attributable to at least one energy source (10), at least one connecting line (80, 90) and / or at least one electronic consumer (41, 42, 43, 52, 53, 60) deviates from a setpoint by at least a first predetermined amount and / or over at least a predetermined time by at least a second predetermined amount, which is equal to or differs from the first predetermined amount.

2. Energy management system (1) according to claim 1, wherein the at least one electrical resistance unit (20) is 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 at least one control device measures the amount of deviation according to a voltage and / or a current.

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 the at least one connecting line (80, 90).

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 deviation of the electrical energy by the at least first and / or second predetermined amount.

7. Energy management system (1) according to one of the preceding claims, wherein the control device (21, 70) is configured to connect and disconnect the at least one electrical resistance (20a) of the at least one electrical resistance unit (20) with the at least one connecting line (80, 90) for a predetermined period of time, in particular to repeat the connection and disconnection until the electrical energy attributable to the at least one energy source (10), the at least one connecting line (80, 90) and / or the at least one electronic consumer (41, 42, 43, 52, 53, 60) has reached the setpoint or deviates only by a third predetermined amount, which is smaller than the first predetermined amount and / or the second predetermined 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 low-voltage energy to at least one second electronic consumer group (41, 42, 43) with at least one electronic consumer (41, 42, 43) 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 connectable to 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), 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 electrical energy attributable to the at least one energy source (10), the at least one connecting line (80, 90) and / or the at least one electronic load (41, 42, 43, 52, 53, 60) deviates from a setpoint by at least a first predetermined amount and / or over at least a predetermined time by at least a second predetermined amount, which is equal to or differs from the first predetermined amount.

14. Computer program product with code means designed to perform 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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