ENERGY MANAGEMENT DEVICE AND METHOD FOR PROVIDING AN ENERGY ESTIMATE OF AN ENERGY STORAGE SYSTEM

Description

[0001] The invention relates to the technical field of transport systems. In particular, the present invention relates to an energy management device, a method for providing an energy estimate of an energy storage device, and a means of transport.

[0002] Ever newer electrical energy storage technologies and further developed drive technologies, combined with reduced manufacturing costs, are driving the development of new means of transport and locomotion, such as hoverboards, and are also leading to the electrification of more and more conventional means of transport, such as scooters or bicycles.

[0003] Electrical energy storage systems are also increasingly being installed in means of transport such as cars or trucks, particularly because of their purported better climate compatibility. These vehicles are offered on the market as, for example, pure electric vehicles (EVs) or battery-powered electric vehicles (BEVs), as hybrid electric vehicles (HEVs) or as plug-in hybrid electric vehicles (PHEVs).

[0004] However, a major uncertainty for users of electrically powered transport vehicles is that the state of charge of the energy storage system, and therefore the range and / or usage time, is difficult to predict.

[0005] While lightweight vehicles like e-bikes or e-scooters can usually continue to be used without problems or be transported to a charging station if their energy reserves are depleted, an empty battery in a car or truck poses a major problem. Such a heavy vehicle can usually only be transported to a charging station at considerable expense if it breaks down.

[0006] Therefore, display devices were developed that can show a user of the means of transport at least the charge level of the energy storage and, if necessary, an estimated range derived from it.

[0007] German patent application DE 10 2013 002 243 A1 relates to a technology for displaying a range indicator for a vehicle. One aspect of this method comprises determining the vehicle's drive energy reserve and calculating the vehicle's range based on this drive energy reserve; retrieving traffic network information, which includes information for displaying a traffic network; displaying the traffic network based on the retrieved traffic network information and a range indicator centered around a starting point within the displayed traffic network, highlighting the vehicle's range; determining a destination point; and calculating one or more routes between the starting point and the destination point based on the traffic network information.Determining the remaining distance for one or more routes, wherein the remaining distance extends from the starting point to an endpoint located on the respective route where the drive energy supply runs out, and wherein the endpoint is determined based on traffic network information; and issuing a notification when at least one endpoint located on one of the routes has been determined.

[0008] Document WO 2013 / 026070 A2 describes a battery management unit (BMU) coupled to a battery pack of any vehicle (xEV) that derives at least part of its propulsion power from an electrical energy source, wherein the BMU is configured to determine a residual energy value for the battery pack at least partially based on a minimum cell temperature and a minimum cell state of charge percentage (SOC%), which is determined by the BMU for the battery pack.

[0009] German patent application DE 10 2015 118 976 A1 relates to a method for estimating the range per full charge (RPC) of a vehicle. The method includes a controller that, in response to the detection of a predefined condition affecting the vehicle's energy consumption, can output an RPC and indicators specifying the extent to which the predefined condition influences the RPC to an interface via a controller. An electrically powered vehicle is also provided, comprising one or more vehicle components, a traction battery for supplying energy to the vehicle components, one or more sensors, and a controller. The one or more sensors monitor the vehicle components, the traction battery, and preselected environmental conditions.The controller is designed to generate an output for an interface in response to an input from the sensors, which includes an RPC and indicators that specify the degree of influence of each of the environmental conditions and the operation of the components and the battery on the RPC.

[0010] German patent application DE 10 2018 116 826 A1 describes a vehicle comprising a set of drive wheels, an energy source with available energy, a torque-generating device driven by the energy source to provide drive torque, a transmission configured to receive the drive torque and provide output torque to the set of drive wheels, and a control system. As part of a programmed procedure, the control system predicts the consumption of available energy along a predetermined route using onboard data, offboard data, and a first logic block. It also corrects the predicted energy consumption using onboard data, offboard data, and an error correction loop between a second logic block and the first logic block.Using the corrected energy consumption, the control system also performs a control action with respect to the vehicle, including changing a logic state of the vehicle.

[0011] US Patent 2021 / 0063491 A1 concerns a method for estimating the remaining energy of a battery, whereby a corrected state of charge (SOC) and a state of energy (SOE) of the battery are determined based on the battery's state of health (SOH), cell temperature, and battery current. The remaining energy is derived from the state of energy and the total dischargeable energy of the battery, which is determined based on the state of health and a reference discharge energy. The reference discharge energy is determined based on a constant discharge rate and as a function of the cell temperature and the battery's state of health.

[0012] From GB 2 515 582 A, a method for determining a predicted range of an electric vehicle is known, based on a current vehicle operating cycle and a range model. This range model depends on an energy consumption rate value recorded during a previous vehicle operating cycle and allows the current energy gradient value to be determined.

[0013] Furthermore, DE 10 2018 116826 A1 relates to a method that enables a prediction of the energy consumption and an estimated electric range of a vehicle using offboard and onboard data.

[0014] DE 10 2012 214962 A1 discloses an energy management device for energy storage, comprising an energy storage device, an energy storage management device, an energy estimating device and a range estimating device; wherein the range estimating device is configured to convert the energy estimate into an estimated range.

[0015] The object of the present invention is to create an efficient energy management system for an energy storage device.

[0016] The invention is defined by the features of the independent claims. Advantageous further developments and embodiments are the subject of the dependent claims. Further features, applications, and advantages of the invention will become apparent from the following description and the explanation of exemplary embodiments of the invention illustrated in the figures.

[0017] According to one aspect of the present invention, an energy management device for an energy storage device is provided, comprising an energy storage device, an energy storage management device, an energy estimation device, and a range estimation device. The energy storage management device or battery management system (BMS) is configured to acquire and provide a plurality of energy storage parameters present in the energy storage device.

[0018] The energy estimation device is designed to receive the multitude of energy storage parameters and to provide an energy estimate from the multitude of energy storage parameters.

[0019] The energy estimating device essentially selects only current parameters from the provided multitude of energy storage parameters, where a current parameter is a parameter that influences the current flow into and / or out of the energy storage device.

[0020] The energy management device includes a range estimator, wherein the range estimator is configured to convert the energy estimate into an estimated range, wherein the range estimator uses an energy-range curve represented in current parameters to convert the energy estimate into the range.

[0021] The energy-range curve has a first and a second section. The first section is adapted to the second section in such a way that the energy-range curve forms a continuous curve.

[0022] The second section of the energy-range curve, which lies in the area of ​​low available energy in the energy storage system, has been determined with higher accuracy than the first section of the energy-range curve, which lies in the area of ​​high available energy in the energy storage system.

[0023] The energy estimate is an energy state value (SoE) that allows a statement about the energy content of the energy storage device, battery and / or accumulator.

[0024] The current parameters allow for a very accurate assessment of the charge and / or state of charge (SoC) of the energy storage device.

[0025] The energy content of an energy storage device, especially a rechargeable battery or accumulator, is very difficult to measure directly. It is therefore often calculated using indirect quantities linked by a formula. The electrical energy of a battery can essentially be calculated using the physical quantities of current (I) and voltage (U).

[0026] To determine the battery's state of charge, current and voltage must be continuously measured. While instantaneous readings are generally used, voltage is a very imprecise value that can drop under load. Therefore, for an accurate measurement, the load would need to be disconnected from the battery before taking the measurement.

[0027] The energy estimate is interesting, however, because it allows for a range estimate for a means of transport, such as a car or truck, if typical consumption values ​​for the vehicle are given, for example, in kWh / 100km. These predictions can be further refined by taking into account the topography of the route and the consumption values ​​associated with that topography, such as whether the destination is traversed by hilly and / or flat terrain.

[0028] Advantageously, the current parameter is at least one energy storage parameter, selected from the group of energy storage parameters consisting of a current balance value, an electrical resistance of the energy storage, an instantaneous voltage at the energy storage, an instantaneous current at the energy storage, an energy storage temperature, an age of the energy storage and an inter-cell voltage difference of individual cells of the energy storage, especially if the energy storage is designed as an energy storage pack or energy storage package.

[0029] The amount of charge in a battery can be determined with high accuracy using the current balance value, provided certain boundary conditions are observed. This is because charge itself is only lost to a very small extent in the form of leakage current. Especially with short dwell times of the transport vehicle, any leakage current may be negligible. Therefore, if the state of charge and the inflow and outflow of charge are known, it is possible to calculate very accurately the amount of charge present in the energy storage device.

[0030] Since charge can essentially only disappear in the form of a current, it may be advantageous to use current parameters to determine the energy estimate.

[0031] Physically, the current balance may be described by forming the divergence of the current flow through a surface virtually surrounding the energy storage device, expressed by div () and / or ∮ x .

[0032] It may be possible to predict the range of a battery-powered electric vehicle, where the range is calculated using an algorithm from the available charge of the battery (State of Energy, SoE) and the specific consumption in kWh / 100km.

[0033] By determining the charge and / or current, it may be possible to correct the available battery energy, taking into account the lower voltage of a discharged battery. A voltage-based approach could distort the results due to load-induced voltage drops. The influence of temperature on the battery's resistance is also considered. For example, historical consumption data might be combined with environmental conditions such as ambient temperature and battery cooling to calculate the battery temperature and its internal resistance.

[0034] By considering the current parameters, it may also be possible to use existing energy consumption models to provide an energy estimate after these models have been transformed into current parameters and / or expressed using current parameters.

[0035] By representing an energy-range curve and / or an energy model in terms of current parameters, it may be usable for a current-based approach to range determination. Using current values ​​may essentially avoid inaccuracies due to load-induced voltage dips and the resulting measurement errors, which is why very accurate range estimates can be expected.

[0036] In other words, this specification allows for the determination of a stable estimate of the stored energy, for example in kWh, which converges to a very precise estimate that essentially lies in the near-empty or almost-empty energy range of the energy storage system. A detailed analysis of the range before the energy from the storage system is essentially depleted may therefore be useful, as this is the critical range that could determine whether a charging station can still be reached with the remaining energy. A vehicle powered by the energy storage system could break down if the reserve range is not represented with high accuracy.

[0037] Similarly, a stable prediction of consumption values ​​can contribute to a stable remaining range display. The prediction may become essentially independent of unstable events, such as a voltage drop under load. Therefore, once the second curve segment is reached, a very accurate range determination may be possible. Even if such an unstable event occurs, it may be compensated for and essentially imperceptible in the output value. For example, the lower voltage of a discharged battery may be taken into account. In particular, the load-related voltage drop may have only a minor influence on the current parameters.

[0038] Furthermore, the slope of the curve may be kept constant in the second section to ensure the most continuous possible progression of the remaining range. Changes in the curve's position may be prevented by ensuring that its position remains constant. Physical inaccuracies, such as an increase in energy without an energy input, may be taken into account and / or corrected. Such inaccuracies may be due to unpredictable voltage dips under load, and these may be corrected.

[0039] According to another aspect of the present invention, a transition from the first curve section to the second curve section of the energy-range curve depends on at least one transition criterion, selected from the group of transition criteria consisting of an operating time, a state of charge of the energy storage, a minimum distance to a target and a trigger event.

[0040] The electrical parameters may not be fully available immediately after starting the vehicle and are only determined during the initial stretch of driving. A parameter such as the state of charge can also be influenced by a previous journey. Factors that can affect the remaining range, such as a driver profile, may not be storable and therefore not available at the beginning of a driving cycle. These must be determined during the journey, especially when the driver changes.

[0041] It may also be useful to extend the accuracy of the provided energy estimate to time periods in which an accurate prediction is of high importance, for example, when the energy storage device is almost empty and / or has reached one third of its original charge.

[0042] It may also be possible to increase accuracy and utilize the energy management device by means of a trigger device, such as a switch.

[0043] There may also be a display showing the accuracy with which the current energy estimates are determined.

[0044] In one example, the second curve segment might represent a remaining range of 0% to 40% of the total range. In another example, this range might be 0% to 20%, and in yet another, 0% to 60%. To indicate that this is remaining range, a minus sign can be placed before the percentage value. However, the remaining range can also be represented as an absolute value.

[0045] In one example, the energy estimate is subjected to filtering in order to essentially arrive at a stable curve.

[0046] Filtering, for example using a Kalman filter, can generate a representative value from a large number of measurements, thereby creating a continuous energy-range curve that can provide stable values. In particular, it is important to ensure that the slope of the curve remains constant as energy estimates decrease.

[0047] In one example, the selected energy storage parameters of the energy storage management device are determined by at least one measurement of the instantaneous current, instantaneous voltage, temperature of the energy storage device and / or the internal resistance of the energy storage device.

[0048] According to a further aspect of the present invention, the range estimation device is configured to predict the temperature of the energy storage device and / or the internal resistance of the energy storage device.

[0049] These external parameters can be acquired and provided using sensors and / or probes via the range estimation device and / or the energy storage management device, and then taken into account in the selection process. Using map and / or route information from a navigation system, it may also be possible to generate a prediction based on these parameters. In this way, a parameter relevant to the current flow may be determined very accurately.

[0050] The energy value of the energy stored in an energy storage device may be specified in kWh. If the energy-range curve is given in kWh relative to the remaining range in km, i.e., in kWh / km, the remaining range can be determined by ascertaining the stored energy. If a stable energy estimate can be obtained by determining the energy value based on current parameters, a stable and reliable prediction of the remaining range can also be generated.

[0051] According to another aspect of the present invention, the energy management device has a display device, wherein the display device is configured to display the estimated range.

[0052] The display unit can be a navigation system and / or an on-board computer. It can also be a single display showing a digital range prediction value and / or an estimated range.

[0053] According to a further aspect of the present invention, a method for providing an energy estimate of an energy storage device is described according to claim 6, comprising the acquisition of a plurality of energy storage parameters present in the energy storage device. The method further comprises providing the plurality of acquired energy storage parameters present in the energy storage device, as well as receiving the plurality of energy storage parameters, for example, in another module of an energy management device. The method may also comprise processing the plurality of energy storage parameters and providing an energy estimate from the plurality of energy storage parameters.

[0054] The procedure involves selecting essentially only current parameters from the multitude of energy storage parameters, where a current parameter is a parameter that influences the current flow into and / or out of the energy storage device.

[0055] According to another aspect of the present invention, a program element is provided which, when executed by a processor, performs the method for providing an energy estimate of an energy storage device.

[0056] According to yet another aspect of the present invention, a computer-readable storage medium is provided in which a program is stored which, when executed by a processor, performs the method for providing an energy estimate of an energy storage device.

[0057] A computer-readable storage medium can be a floppy disk, a hard drive, a USB (Universal Serial Bus) storage device, RAM (Random Access Memory), ROM (Read Only Memory), or EPROM (Erasable Programmable Read Only Memory). Other storage media can include an ASIC (application-specific integrated circuit), an FPGA (field-programmable gate array), SSD (solid-state drive) technology, or flash-based storage medium. A web server or cloud can also be used as a storage medium. A communication network, such as the internet, which allows the downloading of program code, can also be considered a computer-readable storage medium. Wireless and / or wired network technologies can be used.

[0058] Alternatively, a processor of the on-board system and / or a VCU (vehicle control unit) can be used to execute the procedure.

[0059] According to another aspect of the present invention, a means of transport is provided which has the energy management device according to the invention.

[0060] A means of transport can be a motor vehicle and / or a truck, an e-bike, an e-scooter and / or a train.

[0061] Further advantages, features, and details will become apparent from the following description, in which—possibly with reference to the drawing—at least one exemplary embodiment is described in detail. Features described and / or illustrated can, individually or in any meaningful combination, constitute the subject matter of the invention, possibly also independently of the claims, and can, in particular, also be the subject of one or more separate applications. Identical, similar, and / or functionally equivalent parts are designated with the same reference numerals.

[0062] They show: Figure 1 shows an energy management device for an energy storage device according to an exemplary embodiment of the present invention. Figure 2 shows an energy-range curve in an energy-range diagram for better understanding of the present invention. Figure 2a shows a voltage-state-of-charge diagram according to an exemplary embodiment of the present invention. Figure 2b shows two energy-range curves in an energy-range diagram according to an exemplary embodiment of the present invention. Figure 3 shows a flowchart for a method for providing an energy estimate of an energy storage device according to an exemplary embodiment of the present invention.

[0063] Fig. 1 Figure 1 shows an energy management device 100 for an energy storage device 106 according to an exemplary embodiment of the present invention. In addition to the energy storage device 106, the energy management device 100 also includes an energy storage management device 103 or a battery management system 103 (BMS), an energy estimating device 104 and an output device 108b, which is connected to the energy estimating device 104 via an interface 108a.

[0064] The energy storage management unit 103 uses corresponding sensors to record a large number of energy storage parameters present in the energy storage unit 106. The energy estimation unit 104 receives at least some of these parameters and calculates an energy estimate from them. It then makes this energy estimate available for further processing via interface 108a.

[0065] The energy estimation device 104 selects only a portion of the available energy storage parameters to determine the energy estimate. From the multitude of available energy storage parameters, it essentially selects only current parameters. These current parameters may be related to the charge of the energy storage device. The charge may also allow conclusions to be drawn about the stored energy.

[0066] A current parameter is a parameter that has an influence on the current flow into and / or out of the energy storage device 106.

[0067] In an energy management device 100, energy estimates can be performed at several points. The energy storage management device 103 may be able to determine an energy estimate value. It does this using a battery model. Alternatively and / or additionally, the energy estimating device 104 may also be able to perform such energy estimates. This device uses a vehicle model for energy estimation.

[0068] The energy management device can be provided as a modular component in a module housing 101 and monitored and controlled by the processor 102.

[0069] An energy estimating device 104 can be connected to the energy storage management unit 103 via the parameter interface 105. The energy estimating device 104 can be connected via the external energy estimating unit 105a to a display unit 108b, which is configured to determine and / or display the range prediction value.

[0070] The display unit 108b, together with the interface 108a for the energy estimate, forms the range estimation unit 108. This unit serves to predict an assumed remaining range and converts the energy estimate into an estimated range, for example by taking future consumption into account.

[0071] In one example, the determination of the range prediction value or the remaining range can also be carried out at least partially in the energy estimating device 104, i.e. the energy estimating device 104 and the range estimating device 108 can support each other.

[0072] Fig. 2 shows an energy-range curve 202 in an energy-range diagram 200 for a better understanding of the present invention.

[0073] The diagram shows the remaining range on the x-axis (204), ranging from -80 km to 0 km. Energy values, ranging from 0 kWh to 20 kWh, are shown on the y-axis (205).

[0074] The energy storage management unit 103 is equipped with several sensors to determine a variety of energy storage parameters. Through appropriate switches and / or connections to the sensors, the energy estimator 104 can select which of the numerous available parameters it will use. It essentially selects only current parameters for energy estimation and essentially blocks non-current parameters. In this way, energy estimation can be performed by considering the charge.

[0075] By using the current parameters associated with the charge, it may be possible to utilize the doctrine that the amount of charge, in particular the SoC (State of Charge), which is an expression of the amount of charge as a percentage of the total charge, cannot be essentially lost in a battery, for example a lithium-ion battery.

[0076] This finding can therefore be used to adjust a modeled energy-range curve 202 with the help of the current parameters so that a stable curve is created. A stable curve might be characterized, for example, by the fact that the curve remains essentially unchanged over a predefined time period.

[0077] The energy range curve 202 of the Fig. 2 It was not developed based on current parameters. At the beginning of the driving cycle, with high energy values, it exhibits an increase in energy and therefore has a discontinuous profile, since, due to the decrease in charge, only a continuous decrease is actually possible.

[0078] The use of current parameters and the realization that the energy may decrease steadily can ensure that the curve is essentially always continuous, in contrast to energy modeled using non-current parameters.

[0079] To derive a state of charge (SoC) from current parameters without prior knowledge of the state of charge, in addition to a lookup table used for energy estimation (which, for example, accounts for voltage drops under high load), another lookup table can be derived from the cell voltage. It must be considered that the voltage can change depending on other influencing factors, even with the same SoC. Such a lookup table might be stored in database 107. Database 107 might therefore contain a lookup table that specifies the voltage as a function of the load and / or a lookup table that specifies the voltage's dependence on another influencing factor.

[0080] In another example, where a known initial value of the state of charge of the energy storage device is available, for example from storage device 207 from the previous driving cycle or after a defined charging process, the value of the state of charge can be determined incrementally by charge balancing by considering the current parameters.

[0081] Once the charge has been determined via the current parameters, it can be converted, transformed, and / or transformed into energy. The energy values ​​obtained in this way may be stable and very reliable, and thus, for example, the energy-range curve 202 may be used to estimate the range.

[0082] Since range prediction is important in the case of a low charge level and / or a low remaining range, the exact range determination may only be activated at a later time.

[0083] The energy-range curve 202 shows two sections, 202a and 202b. In the first section, 202a, where a sufficient energy reserve still exists, calculating the exact range may not be as relevant as in the second section, 202b. In the first section, 202a, the energy-range diagram already exhibits discontinuity and essentially unrealistic behavior. Here, an exact calculation of the remaining range may be unnecessary, whereas in the second section, such a precise range calculation is desirable, as it determines whether a destination can be reached or not.

[0084] The second area 202b is characterized by the formation of a large number of curves 202b', 202b", 202b‴. A range prediction calculation is performed there for various scenarios, for example to prescribe different behaviors to the driver.

[0085] Curve 202b'' shows the estimated range by extrapolation under the condition that the journey continues with the same conditions as before, for example the same driving behavior.

[0086] The maximum range curve 202b' shows the estimated range if the vehicle continues driving at a reduced speed of 10 km / h, and the minimum range curve 202b‴ shows the estimated range if the vehicle continues driving at a speed increased by 10 km / h.

[0087] In other words, diagram 200 shows that if the energy on the y-axis 205 decreases during the journey, and the extrapolation of its average slope, as shown by the prediction curves 202b', 202b", 202b‴, does not intersect zero kWh at a value on the ordinate of y=0 kWh before zero kilometers at an abscissa of x=0 km, then the range is sufficient. The image of diagram 200 can also be displayed as the result of the range prediction on output device 108b or display device 108b, where the use of the current parameters ensures that the curve is stable and that discontinuities such as those shown in Fig. 2 This can be avoided when dealing with high energy and long range.

[0088] Such a stable course is in Fig. 2 however, it is not shown.

[0089] To avoid points of discontinuity, such as in Fig. 2 To avoid errors in the area of ​​high energy values ​​and long remaining ranges, the exact energy calculation can only be activated later, and at the beginning only a lookup table with only small corrections can be used.

[0090] The activation of the more precise calculation using current parameters may be triggered by a transition criterion, for example by an operating time, by a state of charge of the energy storage 106, by a minimum distance to a target; and / or by a trigger event.

[0091] For example, it may take a longer period of time until the parameters are stably available that allow for the most accurate possible conversion of charge quantity into energy and are essentially independent of current. Current itself is a measured value that is recorded at regular intervals, and thus the parameters directly related to the measured current are also constantly measured and provided.

[0092] Parameters that are not directly derived from a current measurement can be determined, for example, from the driver profile and / or route profile. Such parameters can be determined, for instance, by calculating the expected future current from the driver profile and / or route profile. From this, the future battery cell temperature and the ohmic resistance of the storage battery 106 under the expected future load can then be predicted. In other words, non-current parameters are also converted into current parameters in order to predict the expected battery load and the parameters crucial for load dissipation as accurately as possible.

[0093] The longer period until the parameters are available might arise, for example, if a distance of between 10 km and 20 km must first be covered before the more accurate range estimation in the energy management device 100 activates using current parameters. A longer time might also elapse, for instance, until a driver profile has been determined.

[0094] The energy management device 100 allows various provided models of energy range diagrams 200 to be converted into a current parameter space and, with the help of the current parameters, to provide stable and reliable range predictions and / or to provide very accurate estimated ranges 202b', 202b", 202b‴.

[0095] To switch between the SoE diagram 200 and a SoC diagram (not shown in Fig. 2 To be able to convert, a transformation curve that becomes increasingly steep over time may be used, which takes into account that at a full battery and high voltage, one unit of charge corresponds to a greater energy than at low voltage.

[0096] However, such a transformation curve has different shapes at different temperatures and discharge currents, resulting in a family of transformation curves that depend on temperature and / or discharge current. Using the transformation curve, an energy-range curve 202 can also be used with current parameters and applied to obtain stable results, since the dependence of the energy calculation on the power drawn is eliminated.

[0097] For example, the parameters determined from the driver profile and / or route profile can be used to predict a future battery cell temperature and a future ohmic resistance of the storage battery 106 under the future expected load.

[0098] In another example, instead of future values ​​of the instantaneous current and / or instantaneous internal resistance measurements, the multitude of provided energy storage parameters are used to calculate a correction value that enables the transformation between SoE diagram 200 and SoC diagram and does not depend on a transformation curve.

[0099] In range calculations, the effects of current and temperature on energy estimation may cancel each other out, since range calculations use averaged consumption from the immediate past, and thus essentially the same or at least similar corrections are made in range calculations and energy estimations through the use of current parameters.

[0100] Particularly in the area of ​​low energy values ​​and / or small remaining range values, i.e. when the energy storage is almost empty, corrections to the SoE diagram 200 using current parameters are necessary to achieve stable values ​​for the remaining range and to compensate for the low voltages of the batteries.

[0101] In other words, the intention may be to determine both energy consumption and future usage based on electricity parameters. Thus, essentially, both energy and range estimation may be performed using only electricity parameters.

[0102] To determine the areas in which the current parameter-based range measurement can be activated, let us refer again to... Fig. 2 The first curve section 202a of the energy-range curve 202 ranges from remaining range values ​​of approximately -80km to -42km on the abscissa 204 and from energy values ​​of 17.5kWh to approximately 10kWh on the ordinate 205.

[0103] The three second curve segments 202b may have the following properties.

[0104] The maximum range curve 202b' of the energy range curve 202 ranges from range values ​​of approximately -40km to 0km on the abscissa 204 and from energy values ​​of 10kWh to 2kWh on the ordinate 205. Therefore, there is still plenty of energy available at the destination.

[0105] The range prediction curve 202b" of the energy range curve 202 ranges from range values ​​of approximately -40km to 0km on the abscissa 204 and from energy values ​​of 10kWh to 1kWh on the ordinate 205. Therefore, some energy is still available at the destination.

[0106] The minimum range curve 202b‴ of the energy range curve 202, ranges from range values ​​of approximately -40km to 0km on the abscissa 204 and from energy values ​​of 10kWh to 0kWh on the ordinate 205. The target can thus just be reached.

[0107] An energy storage device 106 can, without limitation of generality, be considered an electrical energy storage device 106, in particular a battery and / or accumulator. An electrical energy storage device 106 can, for example, be used as a drive, HV (high voltage), or traction battery in a BEV (battery electric vehicle) and stores electrical energy as an electrical charge. The stored electrical energy can be measured in ampere-hours (Ah) or coulombs (C). In one example, a traction battery 106 could be a lithium-ion battery.

[0108] Considering the discharge behavior of a traction battery 106, it can be observed that, over a short period, the portion of the energy used in the operation of the BEV, and especially the portion used for propulsion, is the primary factor contributing to the discharge of the traction battery. Self-discharge can be largely neglected in such a short-term analysis. It occurs over a period of months and therefore has essentially no influence on a driving cycle, i.e., on the range determination of a BEV.

[0109] The largest factor influencing the range of a BEV is therefore the available energy of the energy storage device 106, which in turn depends on the battery voltage. The battery voltage, in turn, is essentially determined by the instantaneous current drawn from the battery 106 and the battery's internal resistance.

[0110] Energy consumption is monitored by the battery management system (BMS) 103 or the energy storage management unit 103. This unit, for example, shuts off energy consumption from a battery to protect it from deep discharge. A BMS 103 may be part of a larger platform concept.

[0111] For users of a battery electric vehicle (BEV) 103, the technical details regarding the charging and discharging of a battery 106 should ideally remain hidden. The driver of a BEV is primarily interested in how far the charge and / or energy reserve of their battery will last and when the next charging stop needs to be planned. A display device 108b, which shows the remaining range, for example through a graph 200, is essential for this purpose. If only a charge level indicator were displayed, the driver would have to consider, while driving, what other factors could influence the vehicle's range. In particular, they would need to know which current parameters are important for a precise display.

[0112] A range estimator 108 aggregates all range-relevant information and displays a range value 202b', 202b", 202b‴. The range estimator 108 receives its values ​​and parameters from, among other sources, the energy storage management unit 103. It is desirable that the range estimator 108 provides the most stable display values ​​possible, as unstable and, in particular, rapidly changing values ​​could lead to the driver misjudging the range.

[0113] A stable range display can be achieved, for example, by using a selection of current-related parameters from the multitude of parameters and / or measured values ​​provided by the energy storage management unit 103. It is important to ensure that the parameters themselves are as stable as possible and not subject to fluctuations. Fluctuations can occur, for example, if the current draw from a battery 106 varies significantly during the driving cycle due to strong acceleration and / or recuperation. As long as current parameters are used, these fluctuations can be captured by current and / or charge balancing.

[0114] However, if voltages are used to determine energy, such current fluctuations could put a strain on the battery and cause the voltage to drop. In other words, the correct selection of a suitable parameter set from the multitude of available parameters may enable a good, stable, continuous, and reliable predictive model. Since the current currently drawn from battery 106 plays a role in determining the SoE values, fluctuating current values ​​would lead to fluctuating SoE values. By considering the current and determining the SoC, such fluctuations can essentially be eliminated.

[0115] A stable display of remaining range, which does not frequently change its value when a value is displayed and which, in the case of a display of the remaining range as a diagram, essentially maintains its position and / or slope unchanged, may lead to a high level of confidence in a driver of the means of transport.

[0116] Similarly, a constant and essentially non-volatile range display may lead to user trust.

[0117] Therefore, this is in Fig. 1 The BMS 103 or the energy storage management device 103 shown is designed to provide a stable assessment of the energy available in the battery 106 by essentially relying on current parameters which can be readily determined by current and / or charge balancing and are not disturbed or influenced, for example, by the load on the battery 106.

[0118] The energy-range curve 202, which does not rely solely on current parameters, employs complex modeling for range estimation to compensate for, for example, voltage drops under high load. Despite these complex mechanisms, however, it fails to ensure a completely stable curve. Particularly at the beginning of a driving cycle and / or at high energy levels, the energy-range curve 202 exhibits a discontinuous and unphysical behavior, resulting in an increase in energy despite energy consumption.

[0119] The battery cell temperature at the start of a driving cycle can also be dominated by the conditions during the standby phase or soak. Therefore, the stabilized temperature during power draw may be more relevant and thus preferable for estimating usable energy than the battery cell temperature at the start of a driving cycle. As a workaround or alternative, the temperature at the start of a driving cycle is not based on the amount of charge stored during the previous drive, but also on the temperature conditions prevailing in the battery at that time, i.e., also during power draw. The ambient temperature has a weak influence on these temperature conditions in the battery during power draw, while the current has a strong influence.

[0120] While the exact range of the BEV plays a minor role when fully charged, it can become relevant when the state of energy (SoE) values ​​approach the range of -20 km to 0 km. In this range, with the battery nearly empty, the range can be crucial, especially regarding whether the remaining battery energy is sufficient to reach the destination and / or a distant charging station. Therefore, precise calculations are particularly desirable in this range. Until the battery reaches the nearly empty range, however, values ​​from the new driving cycle and / or a prediction based on these values ​​may be available.

[0121] The Fig. 2a shows a voltage-state of charge diagram 300 according to an exemplary embodiment of the present invention.

[0122] The voltage-state-of-charge diagram 300 shows SOC values ​​from 0%, corresponding to a physically completely discharged battery, to 100%, corresponding to a physically completely charged battery, on the abscissa 301. Voltage values ​​from 350 V to 450 V are plotted on the ordinate 302.

[0123] The voltage-state of charge diagram 300 contains two battery voltage-SOC curves 304, 305, namely the effective voltage curve 304 and the instantaneous voltage curve 305.

[0124] The instantaneous voltage curve 305 corresponds to the voltage actually measured at any given time. Advantageously, instead of the usual open-circuit voltage (i.e., the voltage when there is no current flow), the voltage plotted is the voltage present when drawing a typical current expected during driving or a predicted current. However, multiplying the current charge level by the instantaneous voltage at the current state of charge (SoC) would overestimate the energy available from the battery, since a lower state of charge will also result in a lower voltage across the battery.

[0125] This overestimation can be largely avoided by using the effective voltage curve 304. It is calculated by taking the integral of the instantaneous voltage curve 305 from the current state of charge down to a minimum state of charge and then dividing it again by the current state of charge. The result corresponds to the average voltage present during the remaining discharge of the battery, so that the usable energy can be easily estimated by multiplying it by the current state of charge.

[0126] To determine the remaining energy from the amount of charge, the effective voltage curve 304 is preferably used, and the instantaneous voltage curve 305 is used only as an alternative, for comparison purposes. Fig. 2a is marked.

[0127] Both curves 304 and 305 are traversed during the discharge of a battery 106, particularly a high-voltage battery 106, from the 100% state of charge (SOC) value on the right to the 0% SOC value on the left. During discharge, the remaining charge in Ah (ampere-hours) is preferably multiplied at each point in time by the voltage 304 predicted on average during the discharge, and not by the current instantaneous voltage 305. It can be seen from the shape of the two curves 304 and 305 that the effective voltage curve 304 is more linear than the instantaneous voltage curve 305, thus enabling more stable prediction values.

[0128] The effective voltage curve 304 shown applies to a battery 106 at operating temperature, since it can be assumed that, at least at a high state of charge, the battery will heat up accordingly until a critical state is reached. A critical state can be considered to be the discharged state of charge "empty" at 0% SOC or a nearly discharged state of charge at 5% SOC.

[0129] In an alternative embodiment, the energy estimating device 104 can predict the temperature and / or internal resistance of the energy storage device 106. Using the predicted temperature and / or internal resistance, the external voltage 302 of the battery 106, which is specified by the instantaneous voltage curve 305, is then corrected for the temperature expected at any given time, and the remaining discharge 301 is then determined. The battery 106 may, for example, be configured as a battery pack 106.

[0130] To determine the charge, both when using the effective voltage curve 304 and in the alternative embodiment when using the instantaneous voltage curve 305 with temperature correction, the respective curve 304, 305 is integrated from the 0% value up to the current state of charge value 301.

[0131] It is the Fig. 2a It can also be seen that the SoC values ​​301 of the voltage-state-of-charge curves 304, 305 lie within the operating range 303 or the maximum utilized SoC range 303, which extends from approximately 5% to 98% SoC. This allows for the implementation of shutdown mechanisms of the BMS 103, which can, for example, prevent complete discharge and / or deep discharge of the energy storage device 106. On a display device 108b, this range of 5% to 98% can be scaled to 0% to 100%, for example, using the range estimation device 108, so that a user gets the impression of utilizing the full battery capacity, even though they are only using a range of 5% to 98% of the physical charge. To prevent deep discharge, the BMS 103 would shut down the battery 106 at 5%, before the physical 0% discharge is reached.

[0132] The Fig. 2b shows two energy range curves 402 in an energy range diagram 400 according to an exemplary embodiment of the present invention.

[0133] In diagram 400, the remaining range or driving distance is plotted on the abscissa 404, in the range of -60 km to 0 km and from 0 km to 60 km. Energy values ​​or the energy content of the battery are plotted on the ordinate 205, in the range of 0 kWh to 30 kWh.

[0134] Energy-range curve 401 shows an energy-range curve without considering the current parameters. In this curve, the temperature measurement is taken at the beginning of the driving cycle, which is why curve 401 is almost stagnant at the start. This behavior is similarly implausible as the rise in energy-range curve 202 at the beginning of the driving cycle. It can also be seen that while energy is consumed over a distance of more than 10 km, the calculated model also "grows" due to heating, resulting in an excessively flat curve. In extreme cases, energy-range curve 401 can even rise, similar to energy-range curve 202.

[0135] The energy-range curve 402 again shows two curve sections 402a and 402b', 402b'', 402b‴ as well as 402b and 402b', 402b", 402b‴. Here, two variants 402a, 402c of the first curve sections are shown.

[0136] The first curve section 402a of the energy-range curve 402 shows a first variant of a first curve section 402a of an energy-range curve 402 in which a charge model is used.

[0137] The first curve section 402c of the energy-range curve 402 shows a second variant of an energy-range curve 402, in which an energy integral is used.

[0138] Both the first variant 402a and the second variant 402c were corrected taking the current parameters into account.

[0139] Curve 403 is a comparison curve that shows a linear progression of an energy-range curve.

[0140] In both versions of the energy-range curves 402a and 402c, the destination at a charging station is reached at kilometer zero on the abscissa 404. The slight offset between curves 402a and 402b arises because charging has already occurred. However, care is taken to ensure a continuous and essentially offset-free curve, even though a slight offset is visible in the representation.

[0141] Curves 402a and 402b are each continuously continued by the maximum range curve 402b', the range prediction curve 402b'' and the minimum range curve 402b‴, which make a prediction about the range according to the maximum range curve 202b', the range prediction curve 202b'' and the minimum range curve 202b‴.

[0142] All at Fig. 2 The findings made may be considered accordingly Fig. 2b This applies, in particular the description of the components of the energy management device 100.

[0143] However, it should be noted that the charging stop at the in Fig. 2b The depicted journey was planned approximately 60 km before reaching full discharge, thus leaving a further remaining range. However, this is particularly evident in the example of... Fig. 2 , that the prediction can be made so accurately that, if necessary, the range can be extended to the destination by adjusting the driving style, which is represented by the dashed lines 202b', 202b", 202b‴ or 402b', 402b'', 402b‴.

[0144] In Fig. 2b Furthermore, a cumulative curve 406, consisting of thick points, is shown, representing the sum of the distance traveled and the remaining range. This cumulative curve 406 is calculated as the sum of the distance already traveled (in this example, since km -65 or the distance traveled from -65 km) and the remaining range. This is plotted against the y-values ​​405 representing the current energy content in kWh. The calculation result is transformed and plotted in the x-direction 404 instead of the y-direction 405. The result is plotted in the x-direction instead of the usual y-direction.

[0145] The almost vertical course of the sum curve 406, which approximates a vertical line of an essentially perfect prediction course, shows how well a range prediction can be made by taking the current parameters into account.

[0146] Since the forecast represented by the cumulative curve 406 decreases somewhat and the consumption curves become steeper, it can be seen that in the Fig. 2b The example shown shows that the vehicle was driven faster than approximately 0km shortly before reaching the charging station, with a distance value of 404.

[0147] Further corrections can be incorporated into curves 402a and 402b using additional current and temperature dependence curves, taking the expected behavior into account. This consideration of predicted values ​​allows for an improvement compared to curves 202 and 401, where the correction is based solely on actual measurements and not on predicted values.

[0148] The energy storage parameters determined by the BMS 103 or the energy storage management unit 103 are pre-compensated and passed on via the interface 105 to the energy estimating unit 104, which makes a further prediction of the energy values ​​of the battery 106 by, for example, essentially only processing current parameters.

[0149] The range estimation device 108 is designed as a subsequent control system of the energy storage management device 103 and has a range estimation algorithm and / or a procedure which can be designed as a subroutine of the overall control procedure and which records the available energy in the form of current-based energy values.

[0150] The range estimation system 108 also takes into account the energy consumption of additional electrical consumers. These consumption values ​​can be measured using external sensors, but future predictions can only be estimated. Additional consumers often report their energy consumption in kW. However, this energy consumption can be easily converted into kWh / 100km using data from the vehicle as a whole, such as the current speed or the predicted speed from the route planner, and then added to the energy consumption for driving.

[0151] The range estimation device 108 thus combines the current-based values ​​of the available energy and / or the charge of the battery 106 and the expected consumption values ​​to determine a remaining range. The range estimation device 108 may also calculate the consumption values ​​based on current and / or convert them into current-parameter-based values ​​to have a common basis for calculation with the current-based energy values. This may create independence from the voltage, which is difficult and unstable to determine.

[0152] The range prediction values ​​and / or the remaining range determined by the range estimation device 108 can be displayed to a user of the means of transport, in particular the driver of the BEV, via the display device 108b. The display device 108b can be designed as a human-machine interface (HMI), in particular as a screen. Alternatively or additionally, the display device 108b can also be connected to a coordination controller, in which further estimations can then be carried out and / or traffic data can be collected and retrieved.

[0153] Because the energy storage management device 103 or the BMS 103 has access to a database, the BMS 103 can also take into account an a priori known characteristic of the energy storage device 106 or an a priori known characteristic of the battery 106 in order to compensate for the lower voltage of an almost empty battery 106.

[0154] Similarly, the BMS 103 can also detect external parameters using sensors and / or probes and use the instantaneous current in conjunction with an environmental condition to predict the temperature and / or internal resistance of the energy storage device 106. Since the available energy of a battery 106 depends on the battery voltage, which in turn may depend on the instantaneous current through the battery 106 and its internal resistance, current and temperature are influencing factors for the energy stored in the battery 106. It may be advantageous that the temperature of the battery 106 changes very slowly.

[0155] Alternatively or additionally, the state-of-charge monitoring device 103 or the BMS 103 can be configured to filter the SoE values ​​and, for example, generate a constant average value over a longer period. This is because the instantaneous current through the battery 106 can change rapidly while driving, which can lead to problems, especially when the battery is nearly empty, if instantaneous values ​​are used.

[0156] However, the overall design of the energy management device 100 may intend to equip the energy storage management device 103 with as little computing power as possible and to use it essentially only as a supplier of the multitude of parameters.

[0157] Most corrections and / or compensations are performed in the energy estimator 104, which is equipped with sufficient computing power and can potentially utilize processor 102. The energy estimator 104 also has access to a vehicle model.

[0158] Since the battery temperature has an influence on the internal resistance of the battery 106, and the internal resistance has an influence on the energy available in the battery via the voltage, the prediction of the cell temperature of individual cells of the battery 106 may be helpful in estimating the range.

[0159] Because the battery current, in combination with external parameters and / or environmental conditions, such as the outside temperature, and other known parameters, such as the behavior of the battery cooling system, can be used to predict the cell temperature of battery 106 and the internal resistance of battery 106.

[0160] In one embodiment of the present invention, the range estimation device 108 may be adapted to determine a specific consumption using the sensors and / or probes of the BMS 103 and other predictive values ​​and / or historical data, thus calculating the most probable battery current. This calculated expected consumption current can then be used to estimate the power and / or energy consumption expected for the remainder of the journey. From the determined stable remaining energy value of the battery 106 and the estimated future consumption value, a stable prediction for the expected range can be made. This prediction should remain as stable as possible until the destination is reached.Conditions that could lead to an increase in energy consumption, such as steep inclines, can be taken into account by incorporating data from traffic information and / or navigation systems into the range calculation. Similarly, a driving profile or driver profile, such as sporty, aggressive, or defensive, can be considered.

[0161] The Fig. 3 Figure 1 shows a flowchart for a method for providing an energy state value of an energy storage device 106 according to an exemplary embodiment of the present invention.

[0162] Starting from a start state S300, in state S301 a multitude of energy storage parameters present in the energy storage device 106 are recorded, for example by the energy storage management unit 103 measuring specific standard parameters by means of sensors, such as the discharge and / or charge current and / or a cell voltage; in addition, the multitude of recorded energy storage parameters or those present in the energy storage device 106 are made available.

[0163] In state S302, operation S302 involves selecting essentially only current parameters, where a current parameter is a parameter that influences the current flow into and / or out of the energy storage device 106. In other words, current parameters are prioritized and / or filtered out during the selection process.

[0164] In state S303, the reception of numerous energy storage parameters takes place, in particular the selection of current parameters. This selection and reception can, for example, be performed in the energy estimation device 104.

[0165] In state S304, an energy estimate is determined from the multitude of energy storage parameters; in particular from the current parameters, and provided in order to pass the energy estimate, for example, to a range estimation device 108.

[0166] The process ends in state S305.

[0167] Although the invention has been further illustrated and explained by preferred embodiments, it is not limited by the disclosed examples, and other variations can be derived by a person skilled in the art without departing from the scope of protection of the invention. It is therefore clear that a multitude of variations exist. It is also clear that the embodiments mentioned as examples are indeed only examples. Reference symbol list

[0168] 100 Energy management device 101 Module housing 102 Processor 103 Battery management system (BMS) 104 Energy estimation device 105 Interface for providing energy storage parameters 106 Energy storage 107 Database 108 Range estimation device 108a Interface for energy estimate value 108b Display device 200 Energy-Range Diagram 202 Energy-Range Curve 202a First Section of the Energy-Range Curve 202b' Maximum Range Curve 202b'' Range Prediction Curve 202b‴ Minimum Range Curve 204 Abscissa 205 Ordinate 300 Voltage-State-of-Charge Diagram 301 Abscissa 302 Ordinate 303 Operating Range 304 Effective Voltage Curve 305 Instantaneous Voltage Curve 400 Energy-Range Diagram 401 Energy-Range Curve without Consideration of Current Parameters 402 Energy-Range Curve with Consideration of Current Parameters 402a, 402 First Curve Section of an Energy-Range Curve 402b' Maximum Range Curve 402b" Range Prediction Curve 402b‴ Minimum Range Curve 403 Comparison Curve 404 Abscissa 405 Ordinate 406 Cumulative Curve S300... S305 Process steps 402b"Range prediction curve 402b"Minimum range curve 403Comparison curve 404Abscissa 405Ordinate 406Summation curve S300 ... S305 Process steps

Claims

1. Energy management device (100) for a Energy storage device (106), comprising - a energy storage (106); - one Energy storage management device (103); - one Energy estimation device (104) and - one range estimation device (108); wherein the energy storage management device (103) is Capture and Providing a variety in the energy storage (106) available energy storage parameters furnished is wherein the energy estimation device (104) for Receiving the multitude of energy storage parameters and for the Provide an energy estimate from the multitude of energy storage parameters furnished is ; wherein the energy estimation device (104) from the provided variety of energy storage parameters in the essential only selects current parameters ; where a current parameter is a parameter that affects the current flow in and / or from the energy storage device (106) a Influence has; wherein the range estimation device (108) is arranged is to convert the energy estimate into a Estimated range (202b', 202b", 202b‴) and wherein the range estimation device (108) for Converting the energy estimate into the range one Energy-range curve (202) which is expressed in current parameters shown is ; through this characterized in that the energy -range curve (202) has a first (202a) and one second (202b) curve section has ; where the second Curve section (202b) of the energy-range curve (202), which in the Area one low existing energy in the Energy storage device (106) is located ; with one higher accuracy determined been is when the first Curve section (202a) of the energy-range curve (202), which in the Area one high existing energy in the energy storage device (106) is located ; and where the first Curve section (202a) to the second curve section (202b) adjusted is that the energy-range curve (202) is a continuous Curve (202) forms .

2. Energy management device (100) according to Claim 1, wherein the current parameter at least a energy storage parameters is selected from the group of Energy storage parameters, consisting out of : - electricity balance value ; - electric Resistance of the energy storage device (106); - instantaneous voltage on energy storage (106); - instantaneous current on energy storage (106); - energy storage temperature ; - Age of the energy storage (106) and - inter- cell voltage difference individual Cells of the energy storage (106).

3. Energy management device (100) according to Claim 1 or 2, wherein a transition from the first Curve section (202a) to the second Curve section (202b) of the Energy-range curve (202) of at least one transition criterion depends on selected from the group of transition criteria consisting out of : one operating time ; one state of charge of the energy storage device (106); one minimum distance to one target ; and a trigger event .

4. Energy management device (100) according to one of claims 1 to 3, wherein the Energy estimation facility (104) established is to predict the temperature of the energy storage device (106) and / or the internal resistance of the energy storage device (106) .

5. Energy management device (100) according to one of claims 1 to 4, further having : - one display device (108b); wherein the display device (108b) is Display the estimated range furnished is .

6. Proceedings for the Provide an energy estimate one energy storage device , comprising : - Capturing a variety in the energy storage (106) available energy storage parameters ; - Providing the multitude of recorded in the energy storage (106) available energy storage parameters ; - Receiving the plurality of energy storage parameters ; - Provide an energy estimate from the multitude of energy storage parameters ; where for the Providing the energy estimate in the essential only current parameters selected become , and where a current parameters a parameter which is directed to the flow of current in and / or out of dem energy storage device (106) Influence has ; - Converting the energy estimate into a estimated range ; where for the Converting the energy estimate into the range an energy range curve (202) is used , which in current parameters shown is ; through this characterized in that the energy range curve (202) has a first (202a) and a second (202b) curve section has ; where the second Curve section ( 202b) of the energy range curve (202), which in the Area one low available energy in the Energy storage device (106) is located ; with a higher accuracy determined been is , as the first Curve section ( 202a ) of the energy range curve (202), which in the Area one high available energy in the energy storage device (106) is located ; and where the first Curve section (202a) to the second curve section (202b) adjusted is that the energy-range curve (202) is a continuous Curve (202) forms .

7. Means of transport with a Energy management device (100) according to one of claims 1 to 5.