Method for operating an electric vehicle and electric vehicle

Abstract

This invention relates to a method for operating an electric vehicle and an electric vehicle comprising: an electrical drive unit for the vehicle's driving motion; a control unit for controlling the vehicle's driving motion; a first energy storage device, particularly configured as a rechargeable battery device, for supplying a first DC voltage to the control unit; a second energy storage device, particularly configured as a double-layer capacitor device, and / or the second energy storage device charging and discharging faster than the first energy storage device, for supplying a second DC voltage to the drive unit; and a power supply unit, particularly intermittently providing a DC output voltage, wherein the first energy storage device is connected to the second energy storage device, particularly electrically, via a conversion device, wherein the connection between the first energy storage device and the power supply unit, particularly an electrical connection, is such that the DC output voltage is substantially equal to the first DC voltage, wherein the conversion device converts the first DC voltage to the second DC voltage, and wherein power flow from the second energy storage device to the first energy storage device is prevented.

Description

Technical Field

[0001] The present invention relates to a method for operating an electric vehicle and an electric vehicle. Background Technology

[0002] Preferably, an unmanned mobility assistance system is used as the electric vehicle. Alternatively, such a vehicle may also be referred to as a driverless transport vehicle (FTF) or AGV (automated guided vehicle).

[0003] An unmanned transport vehicle for transporting heavy loads is known from DE 10 2007 002 242 A1. Such heavy load transportation can be referred to as an application of intralogistics. The unmanned transport vehicle is powered by induction.

[0004] A ground transport rail system is known from DE 195 45 544 A1, in which vehicles are supplied with electrical energy via power lines. To enable vehicle operation even without external power, it is recommended to use electrolytic or gold capacitor storage devices (also known as supercapacitors, farad capacitors, or double-layer capacitors) as the power source.

[0005] A supercapacitor power supply unit for an electric vehicle is known from US 6,265,851 B1. This electric vehicle has two energy storage devices that can be selectively used to drive the vehicle.

[0006] An unmanned transportation system is known from EP 2 419 364 A1, which has two energy storage devices: a double-layer capacitor and a battery. During normal operation, the double-layer capacitor supplies energy to the drive unit, i.e., the motor. In an emergency, i.e., when the voltage in the double-layer capacitor drops below a certain level, operation switches to battery mode. The drive unit is then powered solely by the battery until the double-layer capacitor is recharged at a charging station.

[0007] A method for operating an electric vehicle and an electric vehicle are known from DE 10 2017 005 153 A1, wherein the vehicle has a hybrid memory device and a double-layer capacitor device. These two memory devices can selectively supply energy to the driving drive unit.

[0008] A power supply system for electric vehicles is known from EP 2 535 218 A1. Summary of the Invention

[0009] Therefore, the object of the present invention is to improve the energy management of electric vehicles, especially autonomous driving mobility assistance systems, which have two different types of energy storage devices.

[0010] According to the present invention, this objective is achieved in a method for operating an electric vehicle by means of the features described in claim 1 and in an electric vehicle by means of the features described in claim 15.

[0011] A key feature of this invention in the method of an unmanned mobility assistance system (MAS) for operating electric vehicles, particularly for internal logistics applications, is that the vehicle has: an electrical drive mechanism for the vehicle's movement, particularly for traction; a control mechanism for controlling the vehicle's movement; a first energy storage device, particularly configured as a rechargeable battery device, for supplying a first DC voltage to the control mechanism; and a second energy storage device, particularly configured as a double-layer capacitor device, and / or the second energy storage device charges and discharges more rapidly than the first energy storage device. For supplying a second DC voltage to a driving device, and a power supply unit, the power supply unit intermittently providing a DC output voltage, wherein a first energy storage device is connected to a second energy storage device via a conversion device, particularly electrically connected, wherein the first energy storage device is connected to the power supply unit, particularly electrically connected, particularly such that the DC output voltage is substantially equal to the first DC voltage, wherein the conversion device converts the first DC voltage into a second DC voltage, particularly wherein the first DC voltage is less than the second DC voltage, and / or particularly wherein the first DC voltage is a low voltage, wherein power flow from the second energy storage device to the first energy storage device is blocked.

[0012] Advantageously, the second energy storage device can be designed to provide the necessary driving energy for the MAS during normal operation. The second energy storage device is typically used almost entirely during driving and recharged during breaks in the logistics process. The capacity of the second energy storage device can be matched to the needs of the logistics process and is essentially dependent on the driving distance without external power supply, i.e., the driving distance when the power supply unit is not providing power. By preventing the power flow from the second energy storage device to the first energy storage device, the capacity of the second energy storage device can be selected accordingly and optimally matched to the requirements given the known driving distance. Conversely, a power flow from the first energy storage device to the second energy storage device is possible. This is particularly advantageous in emergency situations, i.e., in unforeseen special circumstances, because energy can be transferred from the first energy storage device to the second energy storage device, for example, when the second energy storage device is empty and there is no external power supply. This prevents the vehicle from becoming stationary. While the first energy storage device also recharges during logistical breaks, it must be configured to provide energy to the control device (i.e., control electronics) for a longer period and, if possible, to provide driving power in emergency situations, i.e., during disturbances. Disturbances could be, for example, unexpected obstacles or people along the route, or delays related to other unprepared processes. Throughout this process, the first energy storage device takes over power supply to the control device, and it is advantageously designed to have the longest expected time until the next recharge.

[0013] Advantageously, the first energy storage device has a higher energy density compared to the second energy storage device, and therefore a lower power density and fewer possible charge / discharge cycles in practice. Advantageously, the second energy storage device can be charged and discharged faster than the first energy storage device.

[0014] The first energy storage device is advantageously constructed as a battery device. An example of a battery device is a component consisting of one or more secondary electrochemical elements, particularly nickel and / or iron-based elements. Such secondary electrochemical elements include a negative electrode, a positive electrode, a porous separator separating the negative and positive electrodes, and, particularly, an aqueous alkaline electrolyte, used to impregnate the electrodes and the separator. This nickel and / or iron-based secondary electrochemical element, like a capacitor, can very rapidly provide high pulse currents, but it is more likely to exhibit battery characteristics in other respects. For this battery device, the capacitor equations Q = CU and W = 1 / 2C U are particularly inapplicable. 2Such battery devices offer higher cycle stability, ranging from 1000 to 20000 cycles. Therefore, they can undergo more frequent charge and discharge cycles before exceeding power limits. Furthermore, they exhibit overcharge and deep discharge stability. They can be fast-charged up to 15C. Nevertheless, the charging and discharging speed of these battery devices is slower than that of dual-layer capacitor devices, which is an advantageous design for secondary energy storage devices. Dual-layer capacitor devices are characterized by their ability to charge and fully discharge to zero voltage within seconds. Their cycle stability is in the range of one million cycles.

[0015] In a favorable design, the first DC voltage is a low voltage, such as 12V, 24V, 48V, or 96V. Since the first energy storage device is typically a consumable component and not designed to last the vehicle's lifespan, it is advantageous that it can be replaced by untrained personnel, thus reducing the risk to personnel.

[0016] In an advantageous design, power flow from the second energy storage device to the first energy storage device is prevented by configuring the conversion device as a unidirectional DC / DC converter, particularly as a boost converter or flyback converter.

[0017] Advantageously, the power flow from the second energy storage device to the first energy storage device can be prevented in a simple manner while performing voltage transformation. The unidirectional DC / DC converter is configured such that power flow can only occur from the first energy storage device to the second energy storage device. When the first DC voltage is advantageously lower than the second DC voltage, a favorable design for the unidirectional DC / DC converter is a boost converter or a flyback converter. These converters transform the input voltage into a higher output voltage, where voltage transformation can only occur in that direction. In the case of a flyback converter, it is advantageous that potential isolation exists, thereby electrically isolating the two voltage levels of the first and second DC voltages, and thus enabling electrical safety isolation between the driver power supply and the electronic device power supply. Because only one power flow direction is provided, simple and inexpensive electronic circuitry can be used despite the potential isolation. This is impossible in bidirectional circuits.

[0018] In an advantageous design, the vehicle further includes an energy storage control device, wherein at least one state value of the first energy storage device is detected and transmitted to the energy storage control device, wherein the first state value is the voltage applied to the first energy storage device, and / or wherein the second state value is the current flowing through the first energy storage device, and / or wherein the third state value is the temperature in the first energy storage device.

[0019] Advantageously, it enables state monitoring of the first energy storage device and, when necessary, allows for responses to changes in the state of the first energy storage device.

[0020] The word "also" here should be understood as meaning that the energy storage control device is an independent unit and is therefore constructed separately from the vehicle's control device. The energy storage control device is advantageously integrated with the first energy storage device in a structural unit.

[0021] Sensors, such as current, voltage, and / or temperature sensors, are installed on the first energy storage device to detect state values. Therefore, detection can be implemented, for example, by directly measuring the variables. However, it is also conceivable that the variables are not directly measured but calculated. Advantageously, a communication connection exists between the energy storage control device and the control device.

[0022] The current flowing through the first energy storage device is represented by I1. The value of current I1 can be positive or negative. A positive current I1 is understood as the current that supplies energy to the first energy storage device. Therefore, I1 > 0 is understood as a charging current. A negative current I1 is understood as the current that extracts energy from the first energy storage device. Therefore, I1 < 0 is understood as a discharging current.

[0023] In an advantageous design, the output current supplied by the energy supply unit is adjusted or controlled by means of an energy storage control device according to at least one state value, wherein the current value flowing through the first energy storage device is preset to a target value.

[0024] Advantageously, the required charging current can be regulated or controlled via the energy storage control device. Therefore, the regulation or control of the charging current does not need to be performed by the power supply unit. The power supply unit is simply designed to have an adjustable or controllable current source, thus affecting the value of the output current. This makes it possible to use a very simple power supply unit, i.e., a charger. The charger and conversion device are independent of the characteristics of the first energy storage device. Therefore, standard components can be used for the charger and conversion device, without additional changes required for different types of first energy storage devices. In essence, an intelligent energy storage device is provided that controls or regulates the charger and thus determines the required charging current based on the current state. This operates independently of the possible load current via the conversion device. In the simplest case, the energy storage control device simply shuts off the charger, and only the voltage of the first energy storage device is measured. In more complex cases, the charger obtains a preset amount for the charging current level from the energy storage control device and detects the state of the first energy storage device based on voltage, current, and temperature.

[0025] In an advantageous design, the energy storage control device determines at least one application parameter from at least one state value, and in particular, at least one application parameter is transmitted to the control device, and in particular, the first application parameter is the value of the current at which the first energy storage device can discharge the most, and / or the second application parameter is the state of charge of the first energy storage device, and / or the third application parameter is the aging state of the first energy storage device.

[0026] The advantage here is that it allows for better planning of the logistics process and a more flexible response to short-term changes or disruptions in the logistics application process. When the application parameters are aging, it can prompt the replacement of the primary energy storage device, thereby preventing the failure of the electric vehicle's control unit / control equipment.

[0027] In an advantageous design, power flow, particularly from the power supply unit to the first energy storage device, is prevented when the voltage applied to the first energy storage device exceeds the maximum voltage that can be specified, and / or when the current flowing through the first energy storage device exceeds the maximum current that can be specified, and / or when the temperature generally present in the first energy storage device exceeds the first maximum temperature that can be specified.

[0028] Advantageously, this prevents overload or damage to the first energy storage device, especially due to overcharging. The maximum current here is the positive value of current I1 and the maximum permissible charging current of the first energy storage device. In the simplest case, a switch controllable by the energy storage device is used to disconnect the electrical connection between the first energy storage device and the power supply unit.

[0029] In an advantageous design, power flow from the first energy storage device, particularly to the second energy storage device, is prevented when the voltage applied to the first energy storage device is lower than a preset minimum voltage, and / or when the current flowing through the first energy storage device is lower than a specified minimum current, and / or when the temperature prevalent in the first energy storage device exceeds a specified second maximum temperature.

[0030] Advantageously, this prevents overload or damage to the first energy storage device due to excessively high discharge current and / or temperature. Here, the minimum current is the negative value of current I1 and the maximum permissible discharge current of the first energy storage device. The minimum voltage is a voltage value below which the first energy storage device is deactivated. This avoids complete discharge of the first energy storage device. In the simplest case, a switch controlled by the energy storage device can be used to disconnect the electrical connection between the first and second energy storage devices. For example, the second maximum temperature is equal to the first maximum temperature.

[0031] In an advantageous design, a bidirectional switch is used to block the power flow from and to the first energy storage device, particularly where the bidirectional switch is driven by an energy storage control device. Advantageously, this prevents damage to the first energy storage device. A bidirectional switch is understood as a switch capable of isolating and separating the power flows from and to the first energy storage device independently.

[0032] In a favorable design, energy is delivered to the power supply unit via contact or non-contact and / or intermittent means during operation.

[0033] Here, the advantage of contact-based energy transfer is, for example, the ability to easily charge the energy storage device using a plug-in device.

[0034] The advantage of non-contact energy output here is that it enables safe charging of energy storage devices, for example, via induction. In an advantageous design, the power supply unit includes a rectifier fed by the secondary inductance of the electric vehicle, particularly with capacitors connected in series or parallel to the rectifier, such that the resonant frequency of the resulting oscillating circuit is equal to the frequency of the alternating current flowing into the fixedly arranged primary inductor. Safety is also improved due to inductive energy transfer, and wear on the charging contacts, which would otherwise be necessary, is avoided. Furthermore, a contact-safe implementation scheme can be easily achieved.

[0035] The advantage of intermittent power supply during operation is that it allows power to be supplied in certain areas of the driving route, thereby enabling both energy storage devices to either be recharged or to maintain a fully charged state of charge, thus extending their lifespan because they undergo as few complete charge cycles as possible, and therefore are not frequently fully charged and discharged. This reduces aging. For example, power can be supplied via power line contact grounding. Alternatively, a fixed primary conductor is arranged along the driving route, through which energy is inductively transferred to a secondary inductor arranged in the electric vehicle.

[0036] A key feature of the apparatus according to the invention for supplying a first DC voltage to a first power consumer and a second DC voltage to a second power consumer in an autonomous mobility assistance system for electric vehicles, particularly for internal logistics applications, is that the apparatus comprises: a first energy storage device, particularly configured as a rechargeable battery device; a second energy storage device, particularly configured as a double-layer capacitor device and / or the second energy storage device charging and discharging more rapidly than the first energy storage device; and a power supply unit, which provides a DC output voltage, particularly intermittently, wherein the first DC voltage can be extracted from the first energy storage device.

[0037] The second DC voltage can be extracted from the second energy storage device.

[0038] In this configuration, the first energy storage device is connected to the second energy storage device, particularly electrically, via a conversion device. The conversion device is specifically implemented as a unidirectional DC / DC converter, particularly a boost converter or flyback converter. The first energy storage device is connected to the power supply unit, particularly electrically, such that the DC output voltage is substantially equal to a first DC voltage. The conversion device converts the first DC voltage to a second DC voltage, particularly where the first DC voltage is less than the second DC voltage, and particularly where the first DC voltage is a low voltage. The device is designed to prevent power flow from the second energy storage device to the first energy storage device. Advantageously, this allows for a targeted memory design for supplying power to the second power consumer.

[0039] In an advantageous design, the device further includes an energy storage control device, wherein the energy storage control device is configured to detect at least one state value of the first energy storage device and transmit it to the energy storage control device, in particular wherein the first state value is the voltage applied to the first energy storage device, and / or wherein the second state value is the current flowing through the first energy storage device, and / or wherein the third state value is the temperature in the first energy storage device.

[0040] Advantageously, it enables state monitoring of the first energy storage device and allows for responses to changes in the state of the first energy storage device when necessary.

[0041] In an advantageous design, the output current supplied by the energy supply unit can be adjusted or controlled by means of an energy storage control device according to at least one state value, and in particular, the current value flowing through the first energy storage device can be preset to a target value.

[0042] Advantageously, the required charging current can be regulated or controlled via the energy storage control device. Therefore, the regulation or control of the charging current does not need to be performed by the power supply unit. The power supply unit is simply designed to have an adjustable or controllable current source, thereby affecting the value of the output current. This makes it possible to use a very simple power supply unit, i.e., a charger.

[0043] In an advantageous design, the device also has a bidirectional switch, which can, in particular, intermittently block the power flow from and to the first energy storage device, and in particular, the bidirectional switch can be driven by the energy storage control device.

[0044] Advantageously, the first energy storage device can be protected against overload. Specifically, this is in case the voltage applied to the first energy storage device exceeds a specified maximum voltage, and / or the current flowing through the first energy storage device exceeds a specified maximum current, and / or the temperature generally present in the first energy storage device exceeds a specified first maximum temperature, and / or the voltage applied to the first energy storage device is lower than a specified minimum voltage, and / or the current flowing through the first energy storage device is lower than a specified minimum current, and / or the temperature generally present in the first energy storage device exceeds a specified second maximum temperature.

[0045] In an advantageous design, the first energy storage device, the energy storage control device, and the bidirectional switch are contained within a structural unit, and in particular, the structural unit can be arranged separately on the equipment, enabling the replacement of the structural unit.

[0046] The advantage here is that it allows for the provision of easily replaceable smart energy storage devices. The central control unit does not need to be matched with the new smart energy storage device because the control unit of the first energy storage device, namely charge management, is managed through the smart energy storage device itself.

[0047] In an advantageous design, an electric vehicle, particularly an unmanned mobility assistance system for internal logistics applications, especially for performing the method according to the invention, has an apparatus according to the invention, a first power consumer, and a second power consumer, wherein the first power consumer is a control device for controlling the driving motion of the vehicle, and / or the second power consumer is an electric driving drive device or lifting device or conveying device for the driving motion of the vehicle, particularly for traction of the vehicle.

[0048] The advantage here is that the control device on one side and the controlled power consumer on the other side each have their own energy supply at different voltage levels.

[0049] Further advantages are provided by the dependent claims. The invention is not limited to the combination of features of the claims. For those skilled in the art, particularly for purposes proposed and / or by comparison with the prior art, other reasonable combinations of features of the claims and / or individual claims and / or description features and / or drawings are possible. Attached Figure Description

[0050] Figure 1 The diagram schematically illustrates a device according to the invention for supplying voltage to two power consumers of a mobility assistance system (MAS). The mobility assistance system is also referred to below as MAS.

[0051] Figure 2 A mobile assistance system with two power supplies according to the present invention is illustrated schematically.

[0052] Figure 3 A further embodiment of the mobility assistance system according to the invention is illustrated schematically, which has two power consumers and a smart battery.

[0053] Figure 4 Detailed description Figure 3 The smart battery of the embodiment. Detailed Implementation

[0054] Figure 1 A device for supplying DC voltages U1 and U2 to two power consumers is shown. For this purpose, the device has a first DC voltage interface 1 and a second DC voltage interface 2, to which DC voltages U1 and U2 are applied, as shown. The device has a power supply unit 3 for power supply; in this embodiment, the power supply unit includes a regulator 4 and an adjustable current source 5. The power supply unit can also be referred to as a charger 3. The regulator adjusts the output current I0 of the charger 3, and thus controls the DC output voltage U0. The charger 3 is connected to the first DC voltage interface 1 without a transformer. In this embodiment, the DC output voltage U0 substantially corresponds to the first DC voltage U1 because there are no power consumers in series between the charger 3 and the first DC voltage interface 1.

[0055] The first DC voltage U1 at the first DC voltage interface is different from the second DC voltage U2. For the application of this device in MAS, it is common and advantageous for the DC voltage U2 to be in a low voltage range, advantageously between 120V and 600V, especially 300V, and for the DC voltage U1 to be in a low voltage range, advantageously 12V, 24V, 48V or 96V.

[0056] To convert the first DC voltage U1 into a higher second DC voltage U2, a conversion device 8 is provided between the charger and the second DC voltage interface 2. The conversion device 8 is connected in parallel with the first DC voltage interface 1, so that the DC output voltage U0 is also used as the input voltage for the conversion device 8.

[0057] To buffer and store energy, the device has two energy storage devices 6 and 7. In this embodiment, the first energy storage device 6 is configured as a battery memory and is implemented, for example, as a secondary electrochemical element. In this embodiment, the second energy storage device 7 is implemented as a double-layer capacitor. In the illustrated embodiment, only the first and second energy storage devices are shown separately, exemplarily. However, modularly constructed energy storage devices are also conceivable, consisting of multiple similar or different energy storage devices.

[0058] Each energy storage device is powered by a charger. This energy is storable and can be supplied to the corresponding power consumers. The basic idea of ​​this invention is that the double-layer capacitor 7 only provides energy to those power consumers that can be supplied with the second DC voltage U2. Round-trip charging from the double-layer capacitor 7 to the battery storage 6 is prevented by the conversion device 8. Figure 1 In this embodiment, the conversion device 8 is implemented as a flyback converter. A flyback converter is a potential-isolated unidirectional DC / DC converter. By design, this flyback converter has a diode 9, which prevents the flow of power or energy from the double-layer capacitor to the battery memory at any point in time, i.e., at all times. This allows for the targeted design of the double-layer capacitor to meet the needs of the connected power consumption devices.

[0059] Figure 2 An application of the device for supplying voltage to two power consumers in a MAS is shown. The MAS is not further shown here. In this example, the conversion device 8 is implemented as a boost converter, which is an example of a non-potential-separated DC / DC converter. Therefore, power flow from the double-layer capacitor 7 to the battery memory 6 is also blocked.

[0060] In this embodiment, the first power consumer 10 is configured as a vehicle control unit. Furthermore, this vehicle control unit controls the driving movement of the MAS. The control unit is supplied with a first DC voltage U1, typically 12V, 24V, 48V, or 96V. Other power consumers generally referred to as vehicle electronics, such as safety sensors like laser scanners and corresponding evaluation electronics, can also be supplied with this DC voltage U1.

[0061] For movement, the MAS has a drive unit 11, which can be implemented, for example, as a three-phase AC motor with an upstream three-phase inverter. The inverter here converts the second DC voltage U2 into a three-phase AC voltage in a known manner, and the AC motor, such as a squirrel-cage rotor, operates using this three-phase AC voltage. The drive unit 11 can also have multiple motors, each capable of operating its own inverter. Furthermore, the inverter can also be implemented with feedback capability, allowing the double-layer capacitor 7 to be charged during generator-like operation of the drive motor. Besides the drive unit for traction of the MAS, other power consumers are conceivable for the second DC voltage U2, such as lifting devices for receiving loads or handling devices for moving objects, such as robotic arms. These power consumers 11 are supplied with a second DC voltage U2 in the range of 120V to 600V.

[0062] In principle, it is possible to charge the battery storage device 6 back and forth to the double-layer capacitor 7. This is particularly advantageous when the double-layer capacitor is discharged due to unforeseen interference, i.e., in an emergency. In this case, it is possible that the battery storage device also provides energy to the vehicle's drive. Another conceivable scenario for transferring energy from the first energy storage device to the second energy storage device is that the vehicle is reconnected after a long period of rest, and the charger does not need to provide energy. Even when all power consumers 10 and 11 are turned off while the vehicle is stationary, such as when parked, the energy content of both energy storage devices is reduced due to self-discharge. This self-discharge is many times greater in the case of the double-layer capacitor than in the case of the battery storage device. Therefore, even though power consumer 11 is turned off, the second energy storage device may be discharged after only a few hours or days of rest. With the transfer of energy from the first storage device to the second storage device, the MAS can be restored to a driving-ready state even after a long period of rest without the need for the charger 3 to provide energy. In other words, the MAS does not need to remain or parked in a place where there is an external energy supply.

[0063] The charger 3 for the vehicle can be designed differently. For example, a simple charger with plug contacts can be implemented, allowing the MAS to be supplied with energy via contact at a specific charging station. Similarly, contact-based power supply can be implemented via a power line while the MAS is in motion. Alternatively, non-contact power supply, such as inductive power supply, can also be implemented. This inductive power supply can occur here through coupled primary and secondary inductors. Power supply at a fixed charging station and power supply during MAS operation are also conceivable, for example, via a primary conductor laid in or on the hall floor. Such a primary conductor is, for example, a wire conductor or a coil.

[0064] The energy storage device is primarily designed to supply energy to the MAS during operational phases when it is not powered by the aforementioned external energy source. This operational phase can be a journey between stationary charging stations or a journey away from the primary conductor or power line. Typically, the double-layer capacitor 7 powers the MAS's drive. The drive's power consumption is approximately based on the pre-planned journey without external power supply, as the spatial layout of the charging infrastructure is known.

[0065] exist Figure 1 and Figure 2 In this embodiment, the charger 3 regulates the output current I0 of the adjustable current source 5 using its regulator 4. This output current I0 is divided into a current I1 flowing through the battery storage device, i.e., the charging current of the battery storage device, and a current I2 flowing to the conversion device 8. To prevent damage to the battery storage device, for example, due to overcharging, it is advantageous to take specific measures to properly charge the battery storage device. For this purpose, Figure 3The electric vehicle in the embodiment has a so-called smart battery 14, the detailed structure of which is described again in Figure 4 As shown in the image.

[0066] Figure 3 Implementation examples and Figure 2 The difference in this embodiment lies in the presence of a conversion device 8, symbolically shown as a DC / DC converter 15 with a subsequent diode 9. This illustration aims to show that the conversion device 8 is a unidirectional DC / DC converter, allowing only the flow of power or energy from the charger 3 to the double-layer capacitor 7. The flow of power or energy from the double-layer capacitor 7 to the battery storage 6 is blocked by the conversion device 8. A specific design of the conversion device is described in... Figure 1 and Figure 2 As shown in the figure. However, other matrix design schemes can also be considered as long as unidirectionality can be ensured.

[0067] Another difference is that, Figure 3 In one embodiment, the vehicle has a smart battery 14. This smart battery 14, as... Figure 4 The schematic sketch includes a battery management system 12, a battery storage device 6, and a bidirectional switch 13. Here, the bidirectional switch 13 is optional. The battery management system 12 can also be referred to as an energy storage control device.

[0068] In this embodiment, characteristic variables of the battery memory 6 are measured and thus detected, for example, by means of sensors arranged in the battery memory 6. These variables characterize the state of the battery memory 6 and, for example, the voltage U1 applied to the battery memory 6, the current I1 flowing through the battery memory 6, and the temperature T1 within the battery memory 6. It is also conceivable, for example, to detect only the voltage U1. The detected state values ​​are provided to the battery management system 12, and the battery management system 12 controls or regulates the output current I0 of the charger 3 based on at least one of these state values. For this purpose, the battery management system 12 pre-sets a target value for regulation or control to the charger 3. Figure 3 In the embodiment, the target value I 0,soll This is the target value of the output current I0. Through this target value I... 0,soll The value of the charging current I1 flowing through the battery storage 6 can be adjusted. This ensures that the battery storage 6 is always charged with the allowable charging current I1. Therefore, the battery storage is protected from damage or misuse. The regulation or control of the charging process is pre-defined by the smart battery 14, thus allowing the charger 3 to be designed very simply. Only an adjustable current source 5 is needed, so that the output current I0 can be influenced by the battery management system 12. In this method, it is permissible for the charger 3 to be adjusted below the target value I1. 0,sollThe current. For example, when the effective power of the charger is relative to the current I preset by the smart battery 14. 0,soll This is the case when the value is too low. Importantly, the current I1 flowing through the battery memory must not exceed the allowable value, thus protecting the battery from overload. Therefore, the target value I... 0,soll This represents the maximum upper limit, which can be dynamically matched / adjusted.

[0069] Advantageously, the smart battery 14 includes a bidirectional switch 13, which makes it possible for power or energy flow from and to the battery storage 6 to be blocked independently of each other. In its simplest case, the bidirectional switch is as follows: Figure 4 The battery storage device is symbolically represented by two parallel current branches, each with a controllable switch and a diode connected in reverse parallel. This configuration enables overcurrent and / or overvoltage and / or overheat protection, specifically by the battery management system 12 intermittently interrupting energy delivery or output to the battery storage device 6 based on state variables.

[0070] Advantageously, the smart battery 14 is an independent structural unit, thus all components are integrated into the housing, enabling simple replacement of the smart battery 14. This also makes it possible to retrofit electric vehicles for logistics applications. The regulation or control of the battery charging current I1 is always handled by the smart battery 14 itself, so the same charger 3 and the same conversion device 8 can always be used for different battery storage devices 6 with different characteristic variables.

[0071] Advantageously, the battery management system 12 is connected to the vehicle control unit 10 via a communication connection 16. Different application parameters can be transmitted via this communication connection 16. For example, it is possible for the battery management system 12 to convey the maximum possible discharge current I to the vehicle control unit 10. 1,min Another application parameter could be, for example, the state of charge (SOC) or aging state of the battery storage 6. In this way, the vehicle control unit 10 is always informed of the current state of the battery storage 6.

[0072] List of reference numerals in the attached diagram:

[0073] 1 First DC voltage interface

[0074] 2 Second DC voltage interface

[0075] 3. Energy Supply Unit

[0076] 4. Regulator

[0077] 5. Adjustable current source

[0078] 6 First Energy Storage Device

[0079] 7 Second energy storage device

[0080] 8. Conversion equipment

[0081] 9 diodes

[0082] 10 First power consumption appliance

[0083] 11 Second power consumption device

[0084] 12 Energy Storage Device Control Unit

[0085] 13. Two-way switch

[0086] 14 Smart Batteries

[0087] 15 DC / DC converters

[0088] 16. Communication Connection

Claims

1. A method for operating an electric vehicle, the electric vehicle having: - An electrical driving drive device (11) for the driving motion of the vehicle. - Control device (10) for controlling the movement of the vehicle. - A first energy storage device (6), configured as a rechargeable battery device, which supplies a first DC voltage to the control device (10). - A second energy storage device (7), which is configured as a double-layer capacitor device, and / or the second energy storage device can charge and discharge faster than the first energy storage device (6), the second energy storage device being used to supply a second DC voltage to the driving drive device (11), - and power supply unit (3), which provides DC output voltage, wherein The first energy storage device (6) is connected to the second energy storage device (7) via a conversion device (8). The first energy storage device (6) is connected to the power supply unit (3), so that the DC output voltage is basically equal to the first DC voltage. The conversion device (8) converts the first DC voltage into a second DC voltage, wherein the first DC voltage is less than the second DC voltage, and / or the first DC voltage is a low voltage. Its features are, At all times, the power flow from the second energy storage device (7) to the first energy storage device (6) is blocked. The vehicle also includes an energy storage device (12) that detects at least one state value of the first energy storage device (6) and transmits it to the energy storage device (12). The first state value is the voltage applied to the first energy storage device (6), and / or the second state value is the current flowing through the first energy storage device (6), and / or the third state value is the temperature in the first energy storage device (6). The output current provided by the power supply unit (3) is adjusted or controlled by the energy storage control device (12) according to the at least one state value, wherein the value of the output current is preset as a target value.

2. The method according to claim 1, characterized in that, Power flow from the second energy storage device (7) to the first energy storage device (6) is blocked by configuring the conversion device (8) as a unidirectional DC / DC converter.

3. The method according to claim 1 or 2, characterized in that, The energy storage control device (12) determines at least one application parameter from the at least one state value, wherein the at least one application parameter is transmitted to the control device (10).

4. The method according to claim 3, characterized in that, The first application parameter is the value of the highest discharge current that the first energy storage device (6) can discharge, and / or where, The second application parameter is the state of charge of the first energy storage device (6), and / or the third application parameter is the aging state of the first energy storage device (6).

5. The method according to claim 1 or 2, characterized in that, When the voltage applied to the first energy storage device (6) exceeds a definable maximum voltage (U 1,max ), and / or when the current flowing through the first energy storage device (6) exceeds a definable maximum current (I 1,max ), and / or when the temperature in the first energy storage device (6) exceeds a definable first maximum temperature, the power flow transmitted to the first energy storage device (6) is blocked.

6. The method according to claim 1 or 2, characterized in that, When the voltage applied to the first energy storage device (6) is lower than the minimum voltage that can be given, and / or when the current flowing through the first energy storage device (6) is lower than the minimum current that can be specified, and / or when the temperature in the first energy storage device (6) exceeds the second maximum temperature that can be specified, the power flow from the first energy storage device (6) is blocked.

7. The method according to claim 5, characterized in that, Power flow from and to the first energy storage device (6) is blocked by a two-way switch (13), wherein the two-way switch (13) is driven by the energy storage control device (12).

8. The method according to claim 1 or 2, characterized in that, Energy is supplied to the power supply unit (3) in a contactless or non-contact manner and / or intermittently during operation.

9. An apparatus for supplying a first DC voltage to a first power consumer (10) of an electric vehicle and a second DC voltage to a second power consumer (11), the apparatus comprising: - First energy storage device (6), the first energy storage device is configured as a rechargeable battery device. - A second energy storage device (7), the second energy storage device being configured as a double-layer capacitor device, and / or the second energy storage device being able to charge and discharge faster than the first energy storage device (6), and - Power supply unit (3), through which a DC output voltage can be provided, in, It can extract the first DC voltage from the first energy storage device (6). Among them, a second DC voltage can be extracted from the second energy storage device (7). The first energy storage device (6) is connected to the second energy storage device (7) via a conversion device (8), wherein the conversion device is configured as a unidirectional DC / DC converter. The first energy storage device (6) is connected to the power supply unit (3), such that the DC output voltage is substantially equal to the first DC voltage. The first DC voltage can be converted into a second DC voltage by means of a conversion device (8), wherein the first DC voltage is less than the second DC voltage, and the first DC voltage is a low voltage. Its features are, The device is designed to prevent the power flow from the second energy storage device (7) to the first energy storage device (6) at all times. The device further includes an energy storage control unit (12), wherein the device is designed to detect at least one state value of the first energy storage device (6) and transmit it to the energy storage control unit (12), wherein the first state value is the voltage applied to the first energy storage device (6), and / or wherein the second state value is the current flowing through the first energy storage device (6), and / or wherein the third state value is the temperature in the first energy storage device (6). The output current provided by the power supply unit (3) can be adjusted or controlled by the energy storage control device (12) according to at least one state value, wherein the value of the output current can be preset to a target value.

10. The device according to claim 9, characterized in that, The device also has a bidirectional switch (13) which can block the power flow from and to the first energy storage device (6), wherein the bidirectional switch (13) can be driven by the energy storage control device (12).

11. The device according to claim 10, characterized in that, The first energy storage device (6), the energy storage control device (12) and the two-way switch (13) are contained in a structural unit (14), wherein the structural unit (14) is arranged in a detachable manner on the device so that the structural unit (14) can be replaced.

12. The device according to any one of claims 9 to 11, characterized in that, The DC / DC converter is either a boost converter or a flyback converter.

13. A mobility assistance system for an electric vehicle, the electric vehicle being used to perform the method according to any one of claims 1 to 8, the electric vehicle having a device according to any one of claims 9 to 12, a first power consumer (10), and a second power consumer (11). Its features are, The first power consumer (10) is a control device for controlling the movement of the vehicle, and / or the second power consumer (11) is an electrical driving device, or a lifting device or a conveying device for the movement of the vehicle.

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