Battery management method and battery management system for an on-board battery of a hybrid motor vehicle

Abstract

The invention relates to a method and a system for battery management of an on-board network battery (40) of a hybrid motor vehicle (10) having an internal combustion engine (20) and at least one electric machine (30) and an exhaust gas aftertreatment device (21) with at least one electrically heatable catalytic converter (22), wherein the electric machine (30) can be operated in a generator operating mode for charging the on-board network battery (40). The current state of charge (SOC_curr) of the on-board network battery (40) is continuously monitored and kept at a required state of charge (SOC_req) by means of the electric machine (30), so that the catalytic converter (22) can be reliably electrically heated to an activation temperature by means of the on-board network battery (40) when the internal combustion engine (20) is subsequently started cold. Here, the required state of charge (SOC_req) of the on-board network battery (40) is continuously determined in operation as a function of the ageing states (SOH_Kat, SOH_Bat) of the catalytic converter (22) and the on-board network battery (40) and the ambient temperature (T_exp) that can be expected at the subsequent cold start.

Description

[0001] The present invention relates to a battery management method and a battery management device for battery management of on-board circuit batteries in a hybrid electric vehicle, the hybrid electric vehicle having an internal combustion engine with an electrically heated catalytic converter and at least one electromechanical auxiliary drive device.

[0002] Increasingly stringent legal regulations necessitate arrangements for motor vehicles with internal combustion engines to minimize overall exhaust emissions, particularly harmful components of the exhaust, resulting from the combustion of the air / fuel mixture in the cylinders. To this end, there is a growing trend of combining internal combustion engines with electric motors in hybrid drive systems. In certain operating conditions, the electric motor contributes drive power supplied by the vehicle's battery, thereby requiring less power from the internal combustion engine and producing less exhaust. Furthermore, the electric motor can also be driven by the internal combustion engine or operate as a generator in regenerative braking mode, recharging the vehicle's battery.

[0003] On the other hand, equipping internal combustion engines with exhaust aftertreatment equipment is existing technology. This equipment reduces the environmentally harmful portion of exhaust gases or converts them into harmless components. Different embodiments of the catalytic converter unit and filter device are available for this purpose. In this exhaust catalytic converter, the chemical conversion of harmful substances is achieved through the oxidation or reduction of the corresponding harmful substances. Therefore, the exhaust catalytic converter has an active catalytic zone where chemical conversion occurs via a catalytic reaction.

[0004] These devices or components, as well as the associated methods and processes, are well known to those skilled in the art. It is also known that the efficiency of the catalyst mentioned depends in large part on the operating temperature. The required operating temperatures are mostly in the range of approximately 300°C to approximately 600°C, depending on the fuel and coating. A minimum temperature, the so-called start-up temperature or ignition temperature, is typically required to initiate the conversion process. However, this can lead to unacceptable, but at least undesirable, increases in hazardous emissions, especially during the period immediately following a cold start of the internal combustion engine. This adversely affects the true total hazardous emissions of the internal combustion engine under real driving conditions, the so-called "Real Driving Emissions," which are used as a standard for hazardous emissions. Therefore, efforts should be made to heat the catalyst volume as large as possible to at least the ignition temperature as quickly as possible.

[0005] Therefore, it is necessary to heat the exhaust gas catalytic converter to the desired operating temperature as quickly as possible. To this end, one approach is to implement combustion technology measures, namely, operating the internal combustion engine in a manner that utilizes the residual heat from the exhaust gases to rapidly heat the exhaust gas catalytic converter. However, this typically results in higher fuel consumption and may only shorten, but not eliminate, the period following a cold start of the internal combustion engine during which the catalytic converter has not yet activated, and during which an increased amount of harmful substances are emitted.

[0006] As an alternative or supplementary solution, it is also known to use electrically heated exhaust catalytic converters (EHC = Electrically Heated Catalyst or E-KAT). Such exhaust catalytic converters have their own electrically heated mechanism, which is powered, for example, by the on-board electrical circuit of the vehicle equipped with an internal combustion engine, i.e., by the on-board battery, and this electrically heated mechanism is capable of heating the exhaust catalytic converter to the desired operating temperature. The advantage of electrically heated exhaust catalytic converters is that they can reach operating temperature during the so-called catalytic converter-cold phase, that is, without running the internal combustion engine, i.e., before starting the internal combustion engine. Thus, from the moment the internal combustion engine is started, the harmful substances are already being converted.

[0007] For an electrically heated exhaust gas catalyst, the electric heating mechanism is implemented, for example, in the form of one or more electric heating plates that can be traversed by gas / exhaust gas, which convert electrical power into heating power, and the electric heating plates are arranged close to the catalyst substrate that is not heated itself.

[0008] Because the electric heating plate has a small volume and the inner surface of the heating plate itself has a catalytic coating, this catalytic surface is heated immediately and very quickly.

[0009] The construction of such electrically heated exhaust gas catalysts is described, for example, in published documents DE 19943846A1 and DE4434673 A1.

[0010] To ensure functional reliability in every operating condition, namely timely and adequate heating of the catalyst, a prerequisite is that the charging status of the electric energy storage device used to power the catalyst heating mechanism, such as the on-board battery of a hybrid vehicle, is sufficient at all times, especially when restarting the internal combustion engine from a partially or completely cooled state, to rapidly heat the catalyst to at least the start-up temperature.

[0011] Therefore, the object of the present invention is to provide a battery management method and a battery management system for an on-board circuit battery of a hybrid electric vehicle, which, in particular, ensures the operational reliability of the electrically heated catalyst of the exhaust aftertreatment mechanism during or immediately before starting the internal combustion engine, thereby enabling the catalyst to operate particularly quickly and efficiently, and the catalyst having improved conversion performance, particularly during the starting phase of the internal combustion engine.

[0012] This task is solved according to the features of both the independent method claims relating to battery management methods and the independent apparatus claims relating to battery management systems. Advantageous embodiments of the invention are the subject of the corresponding dependent claims.

[0013] The battery management method and battery management system according to the invention provide high operational reliability of the exhaust gas purification equipment, particularly upon each restart of the internal combustion engine. Advantageously, the state of charge of the on-board circuit battery supplying the electric heating mechanism of the catalytic converter is sufficient, when the internal combustion engine is turned off, to rapidly heat the catalytic converter to at least the start-up temperature upon restarting the engine, even after complete cooling and depending on foreseeable environmental conditions.

[0014] In this way, there is always enough electrical energy to heat the electrically heated catalytic converter (EHC) before starting the internal combustion engine, thus ensuring a high conversion rate of harmful substances when starting the internal combustion engine.

[0015] The battery management method according to the invention is used for an on-board battery in a hybrid electric vehicle having an internal combustion engine and at least one electric motor, wherein the internal combustion engine has an exhaust aftertreatment system with at least one electrically heated catalytic converter and at least one electric motor capable of operating in a generator mode for charging the on-board battery. Here, the battery's state of charge is continuously monitored and maintained at a necessary charge level by means of the electric motor, which reliably ensures that the catalytic converter is electrically heated to its activation temperature by the on-board battery during a subsequent cold start of the internal combustion engine. During operation, the necessary charge level of the on-board battery is continuously determined based on the aging state of not only the catalytic converter but also the on-board battery, and the predictable temperatures of the on-board battery and catalytic converter during subsequent cold starts.

[0016] This invention is based on the understanding that not only the power consumption of the electrically heated catalyst but also the power characteristic parameters of the on-board battery vary within their lifespan and depend on other operating conditions, particularly temperature. This should be taken into account when determining the required charging level.

[0017] The concept of "on-board circuit battery" generally refers to a rechargeable electric energy storage device, such as a battery, which is connected to the electric on-board circuit of a hybrid vehicle or at least a portion thereof, and provides energy for heating a catalytic converter that is electrically heated.

[0018] In one embodiment of the invention, to determine the required charging level of the on-board circuit battery, the nominal charging capacity of the on-board circuit battery is taken into account as another determining factor. Here, "nominal charging capacity" refers to the maximum storable energy specified by the manufacturer in a fully charged battery in a new state. Changes in the maximum charging capacity due to aging are then taken into account in conjunction with the current aging state.

[0019] As another determining factor for determining the necessary charge level of the on-board circuit battery, the estimated starting energy required for the subsequent cold start of the internal combustion engine can be taken into account. Thus, for example, when the catalyst is heated before starting the internal combustion engine, it can be ensured that the on-board circuit battery still has sufficient energy after the catalyst is heated to start the internal combustion engine by means of the electric motor.

[0020] Of course, in addition to determining the necessary charging level of the on-board circuit battery, the nominal charging capacity and the necessary starting power can also be taken into account, thereby advantageously further improving the functional reliability of the battery management method.

[0021] Another embodiment of the battery management method is characterized in that the motor can operate in a recovery operation mode for recovering kinetic energy of the hybrid vehicle, or in a drive operation mode for starting the internal combustion engine or for auxiliary or sole driving of the hybrid vehicle, in addition to a generator operation mode. These operational variations are not excluded. While the aforementioned operation modes cannot be used simultaneously, they can be used alternately according to the requirements of the hybrid vehicle's operation or driving conditions. Therefore, when the state of charge drops below the required charging level, the motor can be operated in generator operation mode to charge the on-board battery when driven by the internal combustion engine. Similarly, during hybrid vehicle operation, the coasting or braking phases can be utilized to feed electrical energy to the on-board battery during recovery operation. Furthermore, the on-board battery can also feed power to the motor in a so-called starter-generator manner to start the internal combustion engine in drive operation mode. In addition, the motor can also provide additional torque, for example, during the acceleration phase of a hybrid vehicle, by being fed by the vehicle's battery circuitry, or, for example, as a standalone, locally emission-free drive unit in urban areas.

[0022] In one improved embodiment of the battery management method according to the invention, the aging state of the catalyst can be determined continuously or intermittently during operation. This can be done, for example, based on the working hours completed by the internal combustion engine, such as by means of a time counter. However, as an alternative or supplementary approach, the average conversion rate during operation can also be determined and used to determine the aging state of the catalyst. Another feasible approach that can be considered as an alternative or supplement to the aforementioned feasible approach for determining the aging state of the catalyst is to determine the average heating duration of the catalyst up to the activation temperature during cold start and deduce the aging state from it.

[0023] This allows for reliable determination of the aging condition of the catalyst during continuous operation, and thereby reliably ascertains the required charge level of the on-board circuitry battery.

[0024] In another embodiment of the method according to the invention, similar to determining the aging state of the catalyst, the aging state of the on-board battery can be determined continuously or intermittently during operation. This is done, for example, taking into account measurements of battery current and / or battery voltage during charging and / or discharging, as well as the temperature of the on-board battery at the time these measurements are collected. However, alternatively or supplementarily, a digitally represented aging model of the on-board battery can also be considered, for example, installed in the electronic control unit, and allowing the aging state of the on-board battery to be calculated during operation based on specific operating hours. In this way, the aging state of the on-board battery can be determined very reliably, and the required charging level can be determined with high accuracy based on this.

[0025] Another advantageous embodiment of the method is characterized in that the predictable temperature of the on-board battery and catalytic converter during a cold start of the internal combustion engine (based on which the necessary charge level of the on-board battery is determined) is based on the ambient temperature at the moment of the prior shutdown of the internal combustion engine. This is because, due to climatic reasons, large temperature fluctuations are generally not expected in the surrounding environment during the average time between the engine shutdown and restart. To improve the reliability of the method, although this simple estimation of the predictable temperature also improves the reliability of the method, it is always possible to assume a temperature reduction of a predetermined amount, such as 5°C or 10°C, for determining the necessary charge level of the on-board battery.

[0026] As an alternative, the predictable temperatures of the vehicle's battery and catalytic converter during a cold start of the internal combustion engine can be estimated based on the temperature variation curve of the ambient temperature during the period prior to a pre-emptive shutdown of the internal combustion engine. In this way, the average temperature level within, for example, the range of daytime and nighttime temperatures, or, if necessary, the width of the temperature variation curve, can be determined, allowing for a reliable estimate of the predictable temperature upon restarting the internal combustion engine. In this case, as mentioned earlier, a safe temperature correction can also be achieved at a lower value.

[0027] In both of the aforementioned scenarios, the temperature of the catalytic converter and the vehicle's electrical battery adapts to the ambient temperature during the assumed cooling period of the system when the internal combustion engine is turned off.

[0028] In another embodiment of the invention, the predictable temperature of the on-board circuit battery and catalytic converter during cold start of the internal combustion engine is estimated based on geographical data of the location of the hybrid vehicle and geographically and seasonally assigned temperature expectations or geographically assigned ambient temperature predictions for the hybrid vehicle. Here, the corresponding location of the hybrid vehicle can be determined, for example, by a GPS system assigned to the vehicle. The geographically and seasonally assigned temperature expectations or temperature predictions can then be retrieved, for example, from a relevant database via an internet connection. Therefore, the wide range of temperature-related location variations of the hybrid vehicle can be advantageously taken into account when estimating the temperature.

[0029] Furthermore, the proposed task is addressed by a battery management system according to the invention for an on-board circuit battery in a hybrid electric vehicle, the vehicle having an internal combustion engine and at least one electric motor, wherein the internal combustion engine has an exhaust aftertreatment system with at least one electrically heated catalytic converter, and the electric motor is capable of operating in a generator mode for charging the on-board circuit battery. Here, the battery management system is represented, for example, by an electronic control unit either separately or integrated into a central vehicle control unit, the battery management system being configured to implement the battery management method according to one of the foregoing embodiments, and is technically connected to at least the on-board circuit battery, the electric motor, and the electrically heated catalytic converter. For example, an operating program is stored in the storage area of ​​the electronic control unit, which is executed to control the method according to the invention.

[0030] Similar to the method according to the invention, the battery management system according to the invention advantageously ensures that the state of charge of the on-board circuit battery that powers the electric heating mechanism of the catalyst is sufficient when the internal combustion engine is turned off to rapidly heat the catalyst to at least the start-up temperature, even after it has fully cooled down and when the internal combustion engine is restarted, depending on foreseeable environmental conditions.

[0031] One embodiment of the battery management system according to the invention is characterized by having an electronic process module configured to acquire measurement data and input information, in particular according to a stored operating program, perform mathematical operations necessary for the battery management method based on the acquired measurement data and information, and output control signals generated therefrom.

[0032] This allows for the rapid and up-to-date acquisition of all relevant data and information, and on this basis, the continuous control or adjustment of the charging level of the vehicle's circuitry battery.

[0033] Another embodiment of the battery management system includes a power module configured to control the power flow between the on-board battery, the motor, and the electrically heated catalyst according to control signals from the aforementioned processor unit.

[0034] This allows for the separation, both technically and spatially, of processor modules that necessarily operate at lower current and voltage, from power modules that operate at higher voltage and current, such as those used to heat catalytic converters and charge vehicle batteries. Therefore, mutual electrical and electromagnetic interference between processor and power modules can be easily avoided.

[0035] The features of the described embodiments, as long as they are not mutually exclusive or can be used only alternatively, can supplement and improve the subject matter of the independent claims individually or in combination.

[0036] The advantages and solutions of the battery management method or battery management system for on-board circuit batteries of hybrid electric vehicles according to the present invention will be explained in detail below with reference to the accompanying drawings, which describe one embodiment.

[0037] Figure 1 A simplified schematic diagram of a hybrid electric vehicle having one embodiment of the battery management system according to the present invention is shown;

[0038] Figure 2 An example flowchart of the battery management method according to the present invention is shown;

[0039] Figure 3A graph is shown illustrating the correlation between the power output of an onboard battery and its aging condition.

[0040] Figure 4 A graph is shown illustrating the correlation between the power output of the vehicle's circuitry battery and its operating temperature.

[0041] Figure 5 A graph showing the correlation between power consumption up to the start-up temperature and the aging state of the heating mechanism of an electrically heated catalyst is presented.

[0042] Figure 1 A simplified schematic diagram illustrates a hybrid electric vehicle 10 having an internal combustion engine 20 and an electric motor 30 integrated into the powertrain. An exhaust aftertreatment mechanism 21 is connected to the internal combustion engine 20, the mechanism having an exhaust pipe 24 connected to the internal combustion engine 20, an electrically heated catalytic converter 22 arranged in the direction of the exhaust pipe 24, and another exhaust aftertreatment component 23, such as a particulate filter, arranged in the exhaust pipe 24 after the catalytic converter. Furthermore, a battery management system 50 according to the invention, having a processor module 51 and a power module 52, an on-board battery 40, and a temperature sensor 56 are arranged in the hybrid electric vehicle 10.

[0043] The processor module 51 of the battery management system 50 is electrically connected to the motor 30, the electrically heated catalytic converter 22, the on-board battery 40, the temperature sensor 56, and the power module 52 via signal connection 70. The power module 52 is electrically connected to the motor 30, the electrically heated catalytic converter 22, and the on-board battery 40 via power connection 60. The signal connection 70 and power connection 60 shown here are also schematic and do not specify the actual number of necessary connections between the various components of the system used to transmit the necessary signal and power flows.

[0044] The signal connection 70 transmits signals, for example, from the vehicle battery 40 to the processor module 51. These signals represent the charging state of the vehicle battery 40 and can be used to determine its aging state. The electrically heated catalytic converter 22 transmits signals, for example, representing the current catalytic converter temperature and, if necessary, its aging state, to the processor module 51. The temperature sensor 56 transmits signals representing the ambient temperature to the processor module 51. Signals, for example, can be transmitted between the motor 30 and the processor module 51 indicating the current operating conditions of the motor 30, or switching the motor 30 to different operating modes, such as generator mode, regeneration mode, or drive mode. Signals for controlling the power flow between the motor 30, the electrically heated catalytic converter 22, and the vehicle battery 40 are transmitted between the processor module 51 and the power module 52. Therefore, the power module 52 is electrically connected to the motor 30, the electrically heated catalyst 22, and the vehicle battery 40 via the power connection 60.

[0045] This configuration of the entire system allows for continuous monitoring of the current charge level (SoC_curr) of the on-board battery 40 and maintenance of it at the necessary charge level (SoC_req) by means of the motor 30. This reliably ensures that the catalyst 22 is electrically heated to the activation temperature in a manner fed by the on-board battery 40 during the subsequent cold start of the internal combustion engine 20. During operation, the necessary charge level (SoC_req) of the on-board battery 40 is continuously determined based on the identified state of aging (SoH-Cat) of the catalyst 22, the identified state of aging (SoH_Bat) of the on-board battery 40, and the ambient temperature (T_exp) of the on-board battery 40 and the catalyst 22 that can be predicted during the subsequent cold start.

[0046] exist Figure 2The diagram schematically illustrates the flow of one embodiment of the method according to the invention using block diagrams. The blocks marked with Use_Bat generally represent the hybrid vehicle's known operating mode using Use_Bat, in which the on-board circuit battery 40 feeds energy into the on-board circuitry for various electrical functions within the vehicle. The blocks immediately following, marked with SoC_curr, symbolize the continuous monitoring of the current charge level Soc_curr. Simultaneously, the required charge level SoC_req is determined, which reliably ensures that the catalytic converter 22 is electrically heated to its activation temperature by the on-board circuit battery 40 during a subsequent cold start of the internal combustion engine 20. This is symbolically represented by the blocks marked with Soc_req. During operation, the required charge level SoC_req is continuously determined based on the aging state SoH_Cat of the catalyst 22, the aging state SoH_Bat of the on-board battery 40, the ambient temperature T_exp of the on-board battery 40 and catalyst 22 during the next cold start, the nominal charge capacity NCC_Bat of the on-board battery, and the starting energy StE_req presumably required for the next cold start of the internal combustion engine 20. This is symbolically represented by corresponding marked squares, which are directly connected to the square SoC_req that symbolically represents the determination of the required charge level SoC_req.

[0047] The squares marked SoC_curr < SoC_req symbolize a continuous comparison between the current charging level SoC_curr of the on-board circuit battery 40 and a specific required charging level SoC_req. If the current charging level SoC_curr is lower than the identified required charging level SoC_req in the comparison, the system is switched to the charging operation mode Char_Bat, in which the on-board circuit battery 40 is charged. This charging operation mode Char_Bat is maintained at least until the current charging level SoC_curr again exceeds the required charging level SoC_req. If this is achieved, the system is switched back to the use operation mode Use_Bat. To avoid constantly switching between the use operation mode Use_Bat and the charging operation mode Char_Bat, the value of the required charging level SoC_req can be increased by a safety margin in the charging operation mode Char_Bat, which must be exceeded before switching to the use operation mode Use_Bat.

[0048] Figure 3A graph is shown illustrating the correlation between the power available for use by the onboard circuitry battery and its aging state and charging level. For this purpose, the available power P (vertical) is plotted relative to the charging level SoC (horizontal). Power curves P_nBat for the onboard circuitry battery in a new state and P_oBat for the onboard circuitry battery at the end of its detailed operating duration are recorded, with the latter continuously below P_nBat.

[0049] The horizontal line, marked with dashed lines, represents the theoretically necessary heating power HP_req, or 5 kW, for heating the catalyst. The intersection of this necessary heating power HP_req with the power curves P_nBat and P_oBat indicates that the required charge level SoC_req_nBat for heating the catalyst in a new battery is approximately 39%, while that of an aged battery is significantly higher, at approximately 53%. Therefore, the required charge level SoC_req for heating the catalyst increases with the age of the on-board battery compared to a new battery. This should be taken into account when determining the required charge level SoC_req.

[0050] Figure 4 A graph illustrating the correlation between the power available from the onboard battery and operating temperature is shown. For this purpose, the available power P (vertical) is also plotted with respect to the charge level SoC (horizontal). Power curves P_+10℃ and P_-10℃ for the onboard battery at +10℃ are plotted, with the latter consistently lower than the P_+10℃ power curve. The theoretically required heating power HP_req, or 5kW, for heating the catalyst is also plotted using a dashed horizontal line. The intersection of the required heating power HP_req with the power curves P_+10℃ and P_-10℃ indicates that the required charge level SoC_req_+10℃ for heating the catalyst in a "hot" state is approximately 30%, while the required charge level SoC_req_-10℃ for a "cold" battery is much higher, at approximately 54%. Therefore, at lower operating temperatures of the vehicle's battery circuitry, the required charge level SoC_req for heating the catalyst is higher than at higher operating temperatures. This should be taken into account when determining the required charge level SoC_req.

[0051] at last, Figure 5A graph illustrating the correlation between the charging level SoC_req required for heating the catalyst in the vehicle circuit battery and the aging state of the catalyst is shown. For this purpose, the available power P (vertical) is also plotted with respect to the charging level SoC (horizontal). The power curve P_-10°C for the vehicle circuit battery at -10°C is recorded. It has been shown that the heating power or energy required for a catalyst in a new state to heat up to the start-up temperature is less than that for an aged catalyst. Therefore, in the example shown, the required heating power HP_req_nC for a catalyst in a new state is found to be approximately 5 kW, and is marked with a dashed horizontal line. In contrast, the required heating power HP_req_oC for a catalyst in an aged state is found to be approximately 6 kW, and is also marked with a dashed horizontal line. The intersection of the two dashed horizontal lines HP_req_nC and HP_req_oC with the power curve P-10°C indicates that the required charge level SoC_req_nC, approximately 53%, for a new catalyst is significantly lower than the required charge level SoC_req_oC, approximately 66%, for an aged catalyst. Therefore, the aging state of the catalyst should also be considered when determining the required charge level SoC_req.

[0052] List of concept / attachment labels:

[0053] 10 Hybrid vehicles

[0054] 20 Internal Combustion Engine

[0055] 21. Exhaust gas after-treatment system

[0056] 22 Catalysts

[0057] 23 Exhaust gas aftertreatment components

[0058] 24 Exhaust pipe

[0059] 30 motors

[0060] 40 Vehicle-mounted circuit battery

[0061] 50 Battery Management System

[0062] 51 processor module

[0063] 52 Power Module

[0064] 56 Temperature Sensor

[0065] 60 Power Connection

[0066] 70 Signal Connection

[0067] SoC automotive circuit battery charging level (State of Charge)

[0068] SoH (State of Health)

[0069] SoH_Bat vehicle battery aging status

[0070] Use_Bat vehicle battery usage and operating mode

[0071] Char_Bat vehicle battery charging operation mode

[0072] NCC_Bat Nominal Charge Capacity

[0073] Current charging level of SoC-curr automotive circuit battery

[0074] SoC_req: Required charge level for the vehicle circuit battery.

[0075] Aging status of SoH_Cat catalyst

[0076] The temperature predicted by T_exp

[0077] StE_req requires starting power

[0078] P power

[0079] P_nBat: Power curve of the new vehicle circuit battery (new Battery)

[0080] P_oBat is the power curve of an aging vehicle battery (oldBattery).

[0081] Power curve of vehicle circuit battery at +10℃

[0082] Power curve of vehicle circuit battery at -10℃

[0083] SoC_req_nBat: Required charging level in the new automotive circuitry battery.

[0084] SoC_req_oBat represents the necessary charging level in the aging automotive circuitry battery.

[0085] SoC_req+10℃ Required charging level under +10℃ heating power conditions

[0086] SoC_req-10℃ Required charging level under +10℃ heating power conditions

[0087] SoC_req_nC: The required charge level in the new catalyst.

[0088] SoC_req_oC is the required charge level in an aging catalyst.

[0089] HP_req: Heating Power required

[0090] HP_req_nC: Required heating power for the new catalyst.

[0091] HP_req_oC is the required heating power for an aging catalytic converter.

Claims

1. A battery management method for an on-board circuit battery (40) of a hybrid electric vehicle (10), the hybrid electric vehicle having an internal combustion engine (20) and at least one electric motor (30). -The internal combustion engine (20) has an exhaust aftertreatment mechanism (21) with at least one electrically heated catalyst (22), and the at least one motor (30) is capable of operating in a generator operation mode for charging the on-board circuit battery (40); The current charge level (SoC_curr) of the on-board circuit battery (40) is continuously monitored and maintained at a necessary charge level (SoC_req) by means of the motor (30), which reliably ensures that the catalyst (22) is electrically heated to the activation temperature by means of the on-board circuit battery (40) during the subsequent cold start of the internal combustion engine (20). During operation, it continuously adjusts according to... - The aging status (SoH_Cat) of the catalyst (22); - The aging status (SoH_Bat) of the on-board circuit battery (40) and - The ambient temperature (T_exp) of the on-board circuit battery (40) and catalyst (22) during the subsequent cold start. To determine the required charge level (SoC_req) of the on-board circuit battery (40). in, The predictable temperature of the on-board circuit battery (40) and catalyst (22) during cold start of the internal combustion engine (20). -Based on the ambient temperature at the moment when the internal combustion engine (20) is pre-shut down or -Based on the temperature change curve of the ambient temperature during the period before the internal combustion engine (20) is pre-disconnected. To estimate.

2. The method according to claim 1, characterized in that, In order to determine the required charge level (SoC_req) of the on-board circuit battery (40), the nominal charge capacity (NCC_Bat) of the on-board circuit battery (40) and / or the estimated starting energy (StE_req) required for the subsequent cold start of the internal combustion engine (20) should be taken into account as additional determining factors.

3. The method according to claim 1 or 2, characterized in that, The motor (30) can also operate in generator mode. -A recovery operation mode for recovering the kinetic energy of the hybrid electric vehicle (10) or - Operates in a drive mode for starting the internal combustion engine (20) or for auxiliary or sole driving of the hybrid vehicle (10).

4. The method according to claim 1 or 2, characterized in that, Continuously or intermittently based on during operation - The working hours and / or completed by the internal combustion engine (20) - Average conversion rate during operation and / or - Average heating duration up to activation temperature during cold start-up To determine the aging status of the catalyst (22).

5. The method according to claim 1 or 2, characterized in that, During operation, continuously or intermittently taking into account -Measurements of battery current and / or battery voltage during charging and / or discharging, and the temperature of the on-board circuit battery (40) present at the time of acquiring the measurements, and / or -Aging model of the on-board circuit battery (40) represented by numbers The aging status of the on-board circuit battery (40) is determined under the following circumstances.

6. The method according to claim 1 or 2, characterized in that, The predictable temperatures of the on-board circuit battery (40) and catalyst (22) during cold start of the internal combustion engine (20) are estimated based on geographic data of the location of the hybrid vehicle (10) and the geographically and seasonally assigned temperature-expected values ​​or the geographically assigned ambient temperature for the hybrid vehicle (10).

7. A battery management system (50) for an on-board circuit battery (40) of a hybrid electric vehicle (10), the hybrid electric vehicle (10) having an internal combustion engine (20) and at least one electric motor (30). -The internal combustion engine (20) has an exhaust aftertreatment system (21) with at least one electrically heated catalytic converter (22) and - The at least one motor (30) is capable of operating in a generator operating mode for charging the on-board circuit battery (40). The battery management system (50) is configured to implement the battery management method according to any one of claims 1 to 6 and is at least connected to the on-board circuit battery (40), the motor (30) and the electrically heated catalyst (22) in terms of control technology.

8. The battery management system (50) according to claim 7, characterized in that, The battery management system has an electronic processor module (51) configured to acquire measurement data, perform mathematical operations necessary for the battery management method based on the acquired measurement data, and output control signals generated therefrom.

9. The battery management system (50) according to claim 8, characterized in that, The battery management system has a power module (52) for controlling the power flow between the on-board battery (40), the motor (30) and the electrically heated catalyst (22) according to the control signal of the processor module (51).

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