WO2020182432A1

WO2020182432A1 - Method for increasing the battery-powered range of a vehicle

Info

Publication number: WO2020182432A1
Application number: PCT/EP2020/054355
Authority: WO
Inventors: Eric De La Chaux
Original assignee: Robert Bosch Gmbh
Priority date: 2019-03-12
Filing date: 2020-02-19
Publication date: 2020-09-17
Also published as: DE102019203342A1

Abstract

The invention relates to a method for increasing the battery-powered range of a vehicle (10) as a fully electric variant (11) with at least one electric machine (18) and as a hybrid variant (32) with an internal combustion engine (34). At least one component in the drive train of the vehicle (10) is temperature-controlled by means of at least one heating element (22) during the charging operation at a charging station.

Description

Method for increasing the battery electric range of a vehicle

Technical area

The present invention relates to a method for increasing the battery-electric range of a vehicle, designed both as a fully electric variant and as a hybrid variant with an internal combustion engine. The invention also relates to the use of the method for controlling the temperature of a transmission in a passenger car, transport vehicle and other vehicle classes.

State of the art

In the case of fully electric vehicles or vehicles with a hybrid drive comprising an internal combustion engine and at least one electric drive, one or more transmissions with one or more are as a rule

Gear ratios used to convert the speed or torque of the electrical machine. When a vehicle of this type is cold started, a transmission, be it a transmission gear, be it a

Differential gear due to high oil viscosities at low temperatures on a very poor efficiency. Such losses in the lubricant that is stored in a transmission lead to heating, which means that the efficiency only gradually improves. The electric range of a fully electric vehicle or a vehicle with a hybrid drive is reduced when the transmission is heated up for the first time, since the transmission is heated by the vehicle's own energy storage device, i.e. H. usually by the traction battery.

Presentation of the invention According to the invention, a method for increasing the battery-electric range of a vehicle, be it implemented as a fully electric variant with at least one electric machine, or implemented as a hybrid variant with at least one internal combustion engine, is proposed. At least one component in the drive train of the vehicle is tempered during the charging process at a charging station via at least one heating element.

In the solution proposed according to the invention, the decisive advantage is that such pre-heating of at least one component in the drive train of the respective vehicle is carried out by energy supplied from the charging device and is not covered by energy that comes from the vehicle's electrical energy store, which is used for the drive of the respective vehicle while driving. The invention

Following the proposed solution, in the overall energetic consideration of the vehicle, the heat capacity of the especially at low

Outside temperatures of the cold drive train when the vehicle is at a standstill used as additional energy storage in the vehicle.

In a further development of the solution proposed according to the invention, thermal masses present in the drive train of the vehicle, in particular housing masses of metallic internals, are tempered. The energy generated to control the temperature of the thermal masses is stored over a certain period of time, in particular in said housing masses, so that, for example, the viscosity of a lubricant stored in a transmission housing can be reduced.

In the method proposed according to the invention, the at least one component in the drive train of the vehicle is temperature-controlled via at least one heating element which is arranged either on the component to be temperature-controlled itself or in the immediate vicinity of the component to be temperature-controlled. In this way, the components for energy storage contained in the drive train of the respective vehicle can be preheated during the charging process at a charging station without the energy store, in particular the traction battery of the vehicle, having to generate this energy, but rather being able to be charged during the stay at the charging station. In the method proposed according to the invention, in particular a transmission and / or a differential provided in the drive train of the vehicle and a lubricant stored in this are directly or indirectly temperature controlled with at least one heating element. The heating element can, for example, be a heating element having a favorable weight, for example a high-voltage heater, which has a particularly compact design and is designed to be weight-saving.

The method proposed according to the invention reduces the torque required to achieve the desired driving state. The load point of the electrical machine is consequently reduced by the pre-heating of the transmission and / or the differential and / or clutches and / or lubricants and / or other mechanical components in the drive train of the vehicle.

With the method proposed according to the invention, heat capacity of the cold drive train of the vehicle is used as an additional energy store in the vehicle while the vehicle is in the vehicle during the charging process.

In the method proposed according to the invention, the initialization of the temperature control of the thermal masses present in the drive train of the vehicle can be triggered by the driver, for example, using an app, or a corresponding trigger command can be given in the vehicle shortly before the end of the charging process at the charging station.

In the case of the solution proposed according to the invention, parallel charging of the can be carried out at the charging station during the charging process of the vehicle

Traction battery on the one hand and a temperature control of at least one

Component in the drive train of the vehicle, on the other hand, so that the vehicle's stay at the charging station can be used very efficiently. Furthermore, the method proposed according to the invention offers the option of controlling the temperature of the thermal masses present in the drive train of the vehicle in coordination with a vehicle-specific one

Initiate navigation system. The solution proposed according to the invention allows that through the

Tempering of the thermal masses that are built into the drive train of the vehicle, the discharge rate of the traction battery is reduced at least at the beginning of the journey of the vehicle, whereby a more favorable operating point of the electric drive can be achieved and the discharge efficiency is increased by the Peukert effect.

The proposed temperature control of at least one thermal mass, which is installed in the drive train of the vehicle, the viscosity of the lubricant that is stored in the gearbox and / or in the differential can be adjusted to a temperature between 20 and 20 by corresponding temperature control of the gearbox and / or the differential ° C and 30 ° C. At such temperatures, the usually in gearboxes or

The lubricant used in differentials has relatively low viscosities, which result in less friction losses.

The method proposed according to the invention is used in particular for

Temperature control of a single or multi-stage transmission and / or

Differential gear used in a transport vehicle or in an electric vehicle (EV = Electric Vehicle), a hybrid vehicle (HEV = Hybrid Electric Vehicle) or in a Plug-In Hybrid Electric Vehicle (PHEV).

The invention also relates to the use of the

proposed method for temperature control of a transmission and / or a differential and / or further mechanical elements of the drive train in a plug-in electric vehicle with a serial hybrid and / or drives close to the wheel or a central drive.

A serial hybrid is a drive in which the

Internal combustion engine drives a generator, which in turn charges a battery. There is no direct drive of the vehicle's wheels by an internal combustion engine. In the case of such serial hybrids, the implementation of the solution proposed according to the invention represents a great advantage, since serial hybrids have a high degree of electrification.

Advantages of the invention The solution proposed according to the invention advantageously offers the possibility of increasing the range of fully electric or partially electrified

Vehicles, such as hybrid vehicles with at least one

Internal combustion engine to improve. The increase in

battery electric range of such vehicles is achieved by

Pre-temperature control of thermal masses, in particular transmission masses, which are present in the drive train of such vehicles. These can be, for example, transmission gears, transfer cases and / or center differentials or also differential gears that are present on the front axle or on the rear axle of such a vehicle. In the method proposed according to the invention, it is crucial that thermal masses that are present in the drive train of such vehicles are preheated in this way by means of supplied energy that comes from a charging device at which such vehicles, in particular their traction batteries, can be charged. The energy for pre-heating the thermal masses that are present in the drive train of such vehicles is not applied by energy from the electrical energy store, in particular the traction battery of such vehicles. This is therefore only available for the ferry operation of such vehicles, so that the battery-electric range of such vehicles can be increased accordingly.

In the solution proposed according to the invention, the existing

Thermal capacity of an ambient temperature, usually cold drive train when the vehicle is stationary, used as an additional energy store in the vehicle. The proposed pre-temperature control can either be initiated by the driver himself via app or in the vehicle shortly before departure or it can also be initiated at the charging station to control the temperature of the thermal masses in the vehicle's drive train during the charging process and use it as an energy store. Furthermore, in coordination with the navigation system of the vehicle, such a

Pre-tempering process can be initiated or omitted.

To control the temperature of the at least one thermal mass present in the drive train of the vehicle, for example

High-voltage heaters designed heating elements are used, which take up little space and can be assembled extremely weight-saving. At least one such heating element can be arranged, for example, on the thermal mass itself or in the immediate vicinity thereof.

With the solution proposed according to the invention, the battery-electric range can be increased, especially at low temperatures in fully electric vehicles, since the load point of the traction drive is reduced by a pre-tempered transmission and the discharge rate of the battery takes place with low current and thus with favorable battery-electric efficiency. The load point describes the need for torque and speed to set a certain driving condition. Such a driving condition is

for example given by the following parameters: constant speed of 50 km / h, constant speed of 1800 rpm, 3rd gear torque requirement 50 Nm. Since the drag losses in the transmission are lower due to pre-heating, less torque is required to generate the same driving state as with a transmission that has not been preheated. This means that the same driving condition is set at lower power. In addition, the lower torque / power requirement results in a lower load on the battery. With a lower load, electrochemical energy storage devices can be discharged more efficiently, which is also known as the Peukert effect. If the vehicle is a hybrid electric vehicle with an electric drive and an internal combustion engine, the method proposed according to the invention can also be used to pre-temperature control thermal masses that are present in the drive train of the vehicle. The temperature of the gearbox and / or the

Differential gear is preferably carried out before departure and is for PO to P2 hybrids and for serial hybrids with drives mounted close to the wheel or

Central drives make sense to increase the battery electric range.

By lowering the load point of the electric drive through the

The solution proposed according to the invention can be achieved by lowering the viscosity of the lubricant stored in a gear housing or in a differential gear, while at the same time using as little energy as possible by introducing heat from outside. For example, by the method proposed according to the invention in

Tempering of thermal masses, such as the thermal masses of a gearbox housing, in particular, reduces the viscosity of the lubricant by heating the housing in which it is stored to a temperature of 20 ° C to 30 ° C. In this temperature range of lubricants at low heat input a large reduction in the viscosity h des

Lubricant reached. At this operating point, with minimal

energetic heating that has to be raised from the outside

Moment of resistance due to drag loss in the gear oil shortly after a cold start can be reduced very effectively. By reducing the viscosity of the

Gear lubricant can minimize the torque required to achieve a certain driving state, whereby the load on the traction battery can be reduced in the first phase of a trip at low temperatures, whereby during this period of time the

Discharge efficiency of the traction battery increased.

Brief description of the drawings

The invention is explained in more detail below with reference to the drawing

described.

It shows:

Figure 1 is a schematic representation of a vehicle as a fully electric

Variant,

FIG. 2 shows a schematic representation of a vehicle as a hybrid variant with an internal combustion engine and various installation locations of an electrical machine and

FIG. 3 shows a viscosity / temperature diagram of lubricants.

Embodiments of the invention

FIG. 1 shows a schematic representation of a vehicle 10 designed as a fully electric variant 11.

FIG. 1 shows a vehicle 10 which is designed as a fully electric variant 11 and comprises a traction battery 12. The vehicle 10 includes a

Front axle 14 and a rear axle 16. In the chassis of the vehicle 10, a transmission 20 is arranged in front of the rear axle 16, and a differential 21 is located on the rear axle 16. As shown in the schematic illustration according to FIG is apparent, the transmission 20 and the differential 21 is at least one

Associated heating element 22, which is designed in an advantageous manner as a high-voltage heater. In addition, power electronics 24 are installed in the vehicle 10 in the fully electric variant 11, via which both the transmission 20 and an electric machine 18 can be controlled. The power electronics 24 are in turn connected to a charging device 26, which comprises a charging connection 28, which is on the outside of a

Vehicle body 30 is located. The traction battery 12 is preferably in

Flat construction in the underbody of the vehicle 10, which is called fully electric

Variant 11 is designed, installed. The pre-heating proposed according to the invention of at least one thermal mass built into the drive train of a vehicle 10 can be carried out, for example, in the fully electric variant 11 of the vehicle 10 according to the schematic representation in FIG Charging connection 28 is supplied, can be divided via the power electronics 24 such that on the one hand the

Traction battery 12 is charged and, on the other hand, the electrical energy supplied via the charging device 26 and the charging connection 28 at the charging station is used, for example to control the temperature of the housing of the electrical machine 18 and to control the temperature of the transmission 20 and / or the differential 21 on the rear axle 16. In the schematic illustration according to FIG. 1, the at least one heating element 22, which is preferably designed as a high-voltage heater, is assigned directly to the transmission 20. Instead of the one heating element 22 shown in FIG. 1, several heating elements 22 could also be arranged. Furthermore, the at least one heating element 22 can also be provided in the vicinity of the thermal masses to be heated, in the present case the thermal mass of the transmission housing of the transmission 20. Due to the pre-heating of at least one thermal mass in the drive train of the vehicle 10 proposed according to the invention, the drive train of the vehicle 10 or its components can be used as an energy storage device as long as the vehicle 10, designed as a fully electric variant 11, is located at a charging station and connected to it via the charging connection 28 is. The charging management within the vehicle 10, implemented as a fully electric variant 11, takes place via the power electronics 24, which transfer the electrical power supplied to the vehicle in parallel operation

Traction battery 12 and the at least one heating element 22 for heating the thermal masses in the drive train. The initialization of the Power electronics 24 with regard to the pre-heating of thermal masses in the drive train of vehicle 10 can be done, for example, via an app; there is also the possibility that the driver

Power electronics 24 is initialized for pre-temperature control. Furthermore, there is also the possibility of pre-heating thermal masses in the vehicle's own navigation system

The drive train of the vehicle 10 implemented as a fully electric variant 11 can be initialized. The charging station itself provides a further option to transfer the charging energy that is supplied by it to the

To divide traction battery 12 and the at least one heating element 22. The proposed solution according to the invention is therefore the

The traction battery 12 is relieved of the fact that its energy content is used to pre-temper the thermal masses present in the drive train of the vehicle 10, such as the housing of the transmission 20 or the housing of the differential 21 or the housing of the electric machine 18 and is therefore no longer available as a battery-electric range . The solution proposed according to the invention increases the battery-electric range of the vehicle 10, designed as a fully electric variant 11, accordingly.

FIG. 2 shows a schematic representation of a vehicle 10 designed as a hybrid variant 32.

According to the schematic illustration in FIG. 2, vehicle 10 shows a hybrid variant 32, since vehicle 10 contains an internal combustion engine 34 according to the illustration in FIG. The internal combustion engine 34 is assigned a starter generator 36 with which the internal combustion engine 34 is started in a conventional manner. The internal combustion engine 34 is connected to a transmission 20 via a separating clutch 46 and a starting clutch 48, which are arranged in series. In the hybrid variant 32 shown schematically in FIG. 2, an electrical machine (not shown in more detail) can be installed at different installation locations. Reference numeral 38 denotes a first installation location of an electrical machine (PI hybrid) at which an electrical machine can be installed. A second installation location for an electrical machine is included

Reference numeral 40 indicated, either in front of or behind the starting clutch 48 on a transmission input shaft of the transmission 20. In addition, the electrical machine can also be provided at a third installation location 42, ie arranged on a transmission output shaft or arranged within the transmission 20 or received on a cardan shaft. There is also the possibility of keeping an electrical machine available at a fourth installation location 44, namely integrated into a rear axle 16 (P4 hybrid).

The pre-heating of thermal masses in the drive train of vehicle 10 proposed according to the invention can be carried out in particular for PO to P2 hybrids, in particular for serial hybrids.

The higher the degree of hybridization and the higher the thermal masses in the drive train, the greater the advantage that can be achieved by using the proposed invention. PO to P2 hybrids are particularly suitable, as the power flow of an electrical machine through the

Manual transmission of the hybrid vehicle 10 runs. The advantage is significant in the case of more highly electrified vehicles 10 in particular, since driving is purely electric from the start.

In vehicles 10, designed as a hybrid variant 32, this can

The method proposed according to the invention can be used sensibly in particular in the case of drives or central drives designed close to the wheel, in order to achieve the battery-electric range increase accordingly.

The course of the viscosity of lubricants plotted against the temperature 52 is illustrated with reference to FIG. FIG. 3 shows that a viscosity 50 is dependent on a temperature 52. The diagram according to FIG. 3 shows a viscosity profile 54 for a first lubricant, a viscosity profile 56 for a second lubricant, and a viscosity profile 58 for a third

Lubricant and a viscosity curve 60 for a fourth lubricant are shown. From the illustration according to FIG. 3 it can be seen that in the temperature range between 20 ° C. and 30 ° C., an operating range is set which is denoted in FIG. In this operating range, denoted by the reference numeral 62, a moment of resistance due to drag losses in the lubricants stored in the transmission 20 shortly after the cold start of the vehicle 10 can be reduced very effectively with minimized energetic heating expenditure - from the outside. The ones from the

Temperature control to a temperature range between 20 ° C and 30 ° C The resulting lowering of the viscosity 50 leads to a considerably reduced torque requirement of an electric machine 18 in the electric ferry operation in order to achieve a certain driving state. Thus, even with a vehicle 10 designed as a hybrid variant 32 in the electric driving mode, the load acting on the traction battery 12 decreases in the first minutes of a journey at lower temperatures. As a result, the discharge efficiency of the increases during this driving phase

Traction battery 12, as shown in connection with FIG. 1 on a vehicle 10 that is designed as a fully electric variant 11.

The invention is not restricted to the exemplary embodiments described here and the aspects emphasized therein. Rather, within the range specified by the claims, a large number of modifications are possible that are within the scope of expert knowledge.

Claims

Expectations

1. A method for increasing the battery-electric range of a vehicle (10) as a fully electric variant (11) with at least one electric machine (18) or as a hybrid variant (32) with an internal combustion engine (34), characterized in that at least one component in The drive train of the vehicle (10) is tempered during the charging process at a charging station via at least one heating element (22).

2. The method according to claim 1, characterized in that im

Drive train of the vehicle (10) thermal masses, in particular housing masses and mechanical components, are tempered.

3. The method according to claim 1, characterized in that the at least one component in the drive train of the vehicle (10) is temperature-controlled via at least one heating element (22) which is arranged on the component to be temperature-controlled or in the vicinity of the component to be temperature-controlled.

4. The method according to claim 1, characterized in that im

Drive train of the vehicle (10) a transmission (20) and / or a differential (21) and a lubricant stored in this is directly or indirectly temperature controlled via at least one heating element (22).

5. The method according to claim 4, characterized in that a load point of the electrical machine (18) is reduced by the pre-heating of the transmission (20) and / or the differential (21).

6. The method according to claim 1, characterized in that during the stay of the vehicle (10) during the charging process, the heat capacity of the cold drive train as an additional

Energy storage in the vehicle (10) is used.

7. The method according to claim 1, characterized in that the temperature control of the thermal masses present in the drive train of the vehicle (10) is triggered by the driver via app or in the vehicle (10) shortly before the end of the charging process at the charging station.

8. The method according to claim 1, characterized in that at the charging station during the charging process of the vehicle (10) a parallel charging of a traction battery (12) on the one hand and a

On the other hand, the components of the drive train of the vehicle (10) are tempered.

9. The method according to claim 7, characterized in that the

The temperature of the thermal masses present in the drive train of the vehicle (10) takes place in coordination with a navigation system of the vehicle (10).

10. The method according to claim 1, characterized in that the temperature control of the thermal masses in the drive train of the

Vehicle (10) the discharge rate of the traction battery (12) is lowered at the beginning of the journey of the vehicle (10).

11. The method according to claim 1, characterized in that the

Viscosity of the lubricant (54, 56, 58, 60), which is stored in the gear (20) and / or in the differential (21), by tempering the gear (20) and / or the differential (21) to a temperature 52 im Range between 20 ° C and 30 ° C is brought.

12. Use of the method according to one of claims 1 to 11 for temperature control of a single or multi-stage transmission (20) and / or a differential (21) in a transport vehicle or in an electric vehicle (EV), in a hybrid vehicle (HEV) = Hybrid Electric Vehicle) or in a plug-in hybrid vehicle (PHEV = Plug-In Hybrid Electric Vehicle).

13. Use of the method according to one of claims 1 to 11 for temperature control of a transmission (20) and / or a differential (21) in a plug-in hybrid electric vehicle with a serial hybrid and / or drives close to the wheel or a central drive and / or an electric vehicle (EV = Electric Vehicle).