DE102019208880A1 - Energy management system for an electrically powered truck - Google Patents

Abstract

The invention relates to an energy management system for an electrically powered truck (HGV) with a tractor (1) and a trailer (3), both of which are used to supply an electrical drive unit (EM) of the tractor (1) with electrical energy (E) Traction engine battery (5) and a trailer traction battery (7), the energy management system being assigned an electronic control device (9) which, when driving, controls the tractor traction battery (5) and the trailer via signal connections (10, 11, 12) -Traktionsbatterie (7) and the electric drive unit (EM) for the electrical energy supply (E) controls, and wherein the electronic control unit (9) has a distribution unit (15) by means of which on the basis of driving parameters (FB) and / or a Accelerator pedal position (FPS) a distribution of electrical energy (E, ER) between the tractor's traction battery (5), the trailer traction battery ttery (7) and the electric machine (EM) takes place. According to the invention, the control device (9) can be switched between at least two energy management functions (19, 21, 23), in particular when driving.

Description

The invention relates to an energy management system for an electrically operated truck according to the preamble of claim 1 and a method for operating a truck with such an energy management system according to claim 9.

In an at least partially electrically powered truck, a tractor traction battery and a trailer traction battery are installed in the tractor and in the trailer of the truck, both of which can supply an electric drive unit of the tractor with electrical energy when driving.

A generic energy management system for such a truck has an electronic control device which controls the tractor traction battery, the trailer traction battery and the electric drive unit for the electrical energy supply via signal connections during driving operation. The electronic control device is assigned a distribution unit (for example a charge controller), by means of which the electric battery is distributed between the tractor traction battery, the trailer traction battery and the electric drive unit on the basis of driving parameters and / or an accelerator pedal position.

In the prior art, the distribution unit of the electronic control device causes the trailer traction battery and the tractor traction battery to be evenly discharged while the vehicle is in motion, in which both the trailer traction battery and the tractor traction battery can have the same charge status at the start of the journey, in particular fully charged are. In the further course of the driving operation, the two traction batteries are discharged with essentially the same temporal discharge curve or with the same discharge rate.

With such an energy management system known from the prior art, after the route destination has been reached, the problem arises that the tractor's traction battery is no longer fully charged after a long journey, but is only partially charged. If the tractor unit continues to drive without a trailer, the available tractor unit range is therefore greatly reduced due to the only partially loaded tractor unit traction battery.

This applies in particular to the case that, after reaching the route destination, the trailer is uncoupled from the tractor and the tractor continues to travel without or with another trailer. Alternatively, the trailer's traction battery may not be fully charged when you continue to drive with another trailer. The driver may want to continue another route with his tractor unit and another trailer immediately after uncoupling his trailer. In this case it can be unfavorable for the driver / fleet manager if the tractor's traction battery is not fully charged.

From the EP 2 842 814 B1 a vehicle trailer is known. From the DE 10 2016 010 573 A1 a method for operating a vehicle axle of a road vehicle / train combination is known.

The object of the invention is to provide an energy management system for an electrically operated truck and a method for operating such a truck, which is functionally expanded compared to the prior art and in particular a perfect separate use of the tractor or the trailer after reaching a route Goal enables.

The object is achieved by the features of claim 1 or claim 9. Preferred developments of the invention are disclosed in the subclaims.

According to the characterizing part of claim 1, the control device can be switched between at least two energy management functions, particularly when driving. With the help of these energy management functions, the energy distribution taking place in the distribution unit can be carried out in different operating modes in order to influence a charging state of the trailer traction battery or the tractor unit traction battery in a targeted manner. Switching between the two energy management functions can preferably take place by means of a manual input by the driver into the electrical control device. As an alternative to this, the switchover between the two energy management functions can also take place automatically, independently of the driver, solely on the basis of driving operating parameters.

The essence of the invention thus relates to the provision of energy management functions that the driver / or the vehicle can use to decide how the load should be distributed between the tractor and the trailer. For example, the amount of energy in the tractor's traction battery can be prioritized and kept as high as possible while driving. In this case, the electrical energy is mainly drawn from the trailer's traction battery. In this way, the (prioritized) tractor Traction battery provides the highest possible energy supply, so that the range of the tractor unit is increased in cases in which the trailer is disconnected after the route destination has been reached.

The driver can preferably choose how the energy is to be distributed in the tractor and trailer traction batteries. Against this background, the electronic control device can work, for example, in a basic function, a prioritization function or in a quick charge function, the mode of operation of which will be described later.

When the basic function is activated, the electric drive unit can be supplied evenly with normal power distribution from the tractor unit traction battery and from the trailer traction battery. When the prioritization function is activated, the electric drive unit can mainly be supplied by the non-prioritized traction battery (e.g. trailer traction battery), while the prioritized traction battery (e.g. tractor unit traction battery) is kept at the highest possible charge level. When the quick charging function is activated, either the trailer traction battery or the tractor unit traction battery is charged as quickly as possible, using the other traction battery and, if necessary, recuperation energy.

For example, a simple (cyclical) functional sequence can take place as follows: First, a driver input can be made, if necessary with the driver's specification of a target charge state in the tractor's traction battery. The input / determination of navigation data can then take place, for example the distance to the destination of the route, the travel time. A difference in the state of charge that is still free in the tractor's traction battery, for example, can then be determined. A power distribution between the trailer traction battery and the tractor unit traction battery can be calculated from this in a distribution unit. From this, a current value can be determined, on the basis of which the control device controls the trailer traction battery and the tractor traction battery.

Another possibility is to store recuperation processes only in the tractor's traction battery, for example, in order to achieve the highest possible charge level by the time the route destination is reached.

With the invention, an energy balance between the tractor traction battery and the trailer traction battery is made possible in a simple manner.

In addition, navigation information or transport information can be used, for example, to determine whether or not the trailer should be separated from the tractor after the route destination has been reached. In this way, an automatic load balancing could take place instead of a manual driver selection.

The solution according to the invention makes it very easy for the driver to determine that the route will be covered without, for example, the tractor having to be charged. In this way, optimal use of the fleet can be ensured (loading management). When uncoupling at the destination of the route, there is the further advantage that the "cheap" trailer can be unloaded and loaded in parallel without the tractor having to be present. This can already take on new tasks. The solution according to the invention also helps the driver to determine how the distance can be influenced, for example by reducing the driving speed and / or by switching off or downshifting functions that consume energy.

The advantages of the invention are an increased range for the tractor after the trailer has been uncoupled, an increase in the available working time of the tractor, as well as ensuring a maximum remaining range when a fully loaded new trailer is directly coupled.

In the following, aspects of the invention are highlighted in detail: In a technical implementation, an energy management function can be designed as a basic function. When activated, the distribution unit (for example a charge controller) can discharge the trailer traction battery and the tractor unit traction battery evenly while driving. This can apply in particular to the case that both the trailer traction battery and the tractor unit traction battery have the same charge states at the start of the journey, that is to say in particular are fully charged. In addition, when the basic function is activated, the two traction batteries can be discharged with the same temporal discharge curve or with the same discharge rate.

Alternatively and / or in addition, an energy management function can be designed as a prioritization function. When activated, the distribution unit can charge one of the two traction batteries while driving, when a route destination is reached at a destination point in time, up to the highest possible charge level (i.e. in particular up to 100%), specifically at a specified priority charge rate.

Alternatively and / or in addition, an energy management function can be designed as a quick charge function. When activated manually or automatically, the distribution unit can charge one of the two traction batteries (either while driving or when the vehicle is at a standstill) immediately (i.e. as quickly as possible) at the highest possible rate of rapid charging up to the highest possible state of charge (i.e. preferably up to 100%). The rapid charging rate is preferably larger than the prioritizing charging rate when the prioritizing function is activated.

A comfortable operation of the control device for the driver during the driving operation is of the utmost importance in order to reliably guarantee the highest possible target charge level of the trailer traction battery or the tractor's traction battery with the help of the prioritization function at the destination. Against this background, the control device can have an evaluation unit which indicates to the driver that the prioritization function is activated in good time while driving. With the aid of the evaluation unit, a switchover point in time or a remaining distance that correlates with it can be estimated or determined during driving operation. The prioritization function must be activated at the latest up to the determined switchover time or from the determined remaining distance so that the tractor's traction battery or the trailer's traction battery can be charged up to the highest possible target when the route destination is reached at the destination time -The state of charge is guaranteed.

With regard to an evaluation unit that is easy to implement in terms of signaling technology, it is preferred if the evaluation unit determines or estimates the switchover time or the remaining driving time on the basis of the following parameters, namely on the basis of the current state of charge of the respective (prioritized) traction battery, the intended one Target state of charge (i.e. preferably 100%), as well as the prioritization charge rate to be used during the prioritization charging process and the current average speed on the route covered so far.

In a preferred embodiment variant, the control device can always work with the basic function in the case of a basic setting. This means that when the energy management functions are not activated, the distribution unit uniformly discharges the trailer traction battery and the tractor unit traction battery while driving, in accordance with the basic function described above. From the start of the journey, the distribution unit therefore carries out energy distribution in accordance with the basic function, until the driver activates the fast charging function or the prioritization function at a switchover point in which the distribution unit has one of the two traction batteries in the continues driving when the route destination is reached at the time of the destination to the highest possible charge level.

Exemplary embodiments of the invention are described below with reference to the accompanying figures.

• 1 in einer Seitenansicht einen elektrisch betriebenen Lastkraftwagen mit einer Zugmaschine und einem Anhänger;
• 2 ein Energiemanagementsystem für den Lastkraftwagen;
• 3 bis 5 in Ansichten entsprechend der 2 das Energiemanagementsystem bei aktivierter Basis-Funktion, bei aktivierter Priorisier-Funktion und bei aktivierter Schnelllade-Funktion;
• 6 bis 8 jeweils Ladezustand-Zeit-Diagramme bei aktivierter Basis-Funktion, bei aktivierter Priorisier-Funktion und bei aktivierter Schnelllade-Funktion; und
• 9 die Priorisier-Funktion als Blockschaltdiagramm.

Show it:

• 1 in a side view an electrically powered truck with a tractor and a trailer;
• 2 an energy management system for the truck;
• 3 to 5 in views corresponding to the 2 the energy management system with the basic function activated, the prioritization function activated and the fast charging function activated;
• 6th to 8th charge status-time diagrams with activated basic function, activated prioritization function and activated quick charge function; and
• 9 the prioritization function as a block diagram.

In the 1 is a side view of a fully electric truck truck with a tractor 1 and a trailer 3 shown. The tractor 1 and the trailer 3 each have a tractor's traction battery 5 and a trailer traction battery 7th on. The two traction batteries 5 , 7th supply an electric drive unit while driving EM ( 2 ) the tractor 1 with electrical energy E. . The two traction batteries 5 , 7th provide a very high battery capacity overall, by means of which the trucks truck can cover longer distances without interruption.

In the 1 Fig. 13 is roughly schematic, as a block diagram, an energy management system for the truck truck illustrated. That in the 2 The block diagram shown is made for an easy understanding of the invention. Hence the 2 (as well as the other figures) only a roughly simplified representation that does not reflect a realistic structure of the energy management system and no realistic software architecture of the energy management system. In the 2 the energy management system has an electronic control device 9 on that via signal connections 10 , 11 , 12th each with power electronics LE the tractor's traction battery 5 , the electric drive unit EM and the trailer Traction battery 7th connected is. In the electronic control device 9 is a distribution unit 15th integrated, by means of which on the basis of driving operation parameters FB and / or an accelerator pedal position FPS an accelerator pedal 17th a distribution of electrical energy E. between the tractor's traction battery 5 , the trailer traction battery 7th and the electric drive unit EM he follows.

As from the 2 is further evident, are in the control device 9 a total of three energy management functions integrated, namely a basic function 19th , a prioritization function 21st and a quick charge function 23 . The three energy management functions 19th , 21st , 23 are via signal lines 25th with a signal input of the distribution unit 15th connected. In addition, the control device 9 a signal generating unit 27 assigned, by means of one of the three energy management functions during driving or when the vehicle is at a standstill 19th , 21st , 23 via a trigger signal S _T can be activated. The trigger signal S _T is based on driving operating parameters FB Generated independently of the driver or alternatively by manual input into an input unit by the driver 29 activated. Depending on the activated energy management function 19th , 21st , 23 can in the distribution unit 15th a distribution of electrical energy in different operating modes E. between the tractor's traction battery 5 , the trailer traction battery 7th and / or the electric drive unit EM done to target a charge level SOC _A the trailer traction battery 7th or a state of charge SOCz the tractor's traction battery 5 to influence while driving.

In the 3 is the energy management system when the basic function is activated 19th shown. They are activated, for example, by a corresponding input into the input unit on the driver's side 29 , whereby the signal generation unit 27 the activation signal STB is generated. The distribution unit therefore discharges when driving 15th both the trailer traction battery 7th as well as the tractor's traction battery 5 evenly. In the charge state-time diagram of the 6th is an example when the basic function is activated 19th the unloading process in progress. This takes place in the 6th during a driving operation over a total driving distance s _{tot, based} on the time when the journey begins t _B until a route destination is reached Z at the destination time t _E . In the 6th exhibit both the trailer traction battery 7th as well as the tractor's traction battery 5 at the start of the journey t _B same charge levels SOC _e.g. ( t _B ), SOC _A ( t _B ), which are at 100%. The two traction batteries 5 , 7th will be in the 6th with identical temporal discharge curves throughout the journey SOCz (t), SOC _A (t) discharged until the route destination is reached Z at the destination time tz. At the destination time tz, the two traction batteries point 5 , 7th in the 6th identical charge levels SOC _Z ( t _E ) and SOC _A ( t _E ) that are in a range of less than 30%.

In the 4th is the energy management system when the prioritization function is activated 21st shown. Accordingly, based on a corresponding driver input into the input unit 29 in the signal generation unit 27 a trigger signal S _{TP is} generated with which the prioritization function 21st is activated. When the prioritization function is activated 21st the discharging process takes place on the two traction batteries 5 , 7th no longer evenly. Rather, the distribution unit transmits 15th excess energy (that is not required for propulsion) E. as well as any recuperation energy generated while driving HE mainly in the direction of the tractor's traction battery 5 . This allows the tractor's traction battery 5 with the achievement of the route target Z at the destination time t _E up to the highest possible target state of charge SOC _, i.e. 100%, should be charged.

In the charge state-time diagram of the 7th is an example of the effect of the prioritization function 21st illustrated. Accordingly, the driving operation starts at the start of the journey t _B initially with the basic function activated 19th , where the two traction batteries 5 , 7th , analogous to 6th to be discharged evenly. At a switching point in time do the driver activates the prioritization function 21st . With the help of the prioritization function 21st the charging / discharging behavior during driving is influenced as follows: The distribution unit 15th distributes the electrical energy E. , HE such that the tractor's traction battery 5 from the switchover time do for the remaining distance STC mainly with excess electrical energy E. (which is not required for the propulsion system) and possibly with recuperation energy HE is supplied. With the achievement of the route destination Z at the destination time t _E is therefore in the 7th the tractor's traction battery 5 _{should be} charged to the highest possible state of charge SOC _, i.e. 100%. The charging of the tractor's traction battery 5 takes place when the prioritization function is activated 21st (i.e. from the time of the switchover do ) with a priority charge rate C _P .

In the 9 are program modules of the prioritization function 21st indicated in a further block diagram. As a result, the prioritization function 21st an investigation unit 31 on that based on the target state of charge SOC _should and based on a current state of charge SOCz (t) the tractor's traction battery 5 a state of charge difference ΔSOC is calculated. The state of charge difference ΔSOC becomes in the Converter unit 33 a current value signal correlating therewith Δl calculated that to the distribution unit 15th is forwarded. Depending on the size of the current value signal Δl controls the distribution unit 15th the trailer traction battery 7th who have favourited the tractor traction battery 5 and the drive unit EM so that the state of charge SOCz the tractor's traction battery 5 until reaching the destination Z up to the target state of charge SOC _should increases.

As from the 9 further shows is the prioritization function 21st an evaluation unit 35 assigned. The evaluation unit 35 has a display screen 37 with which the driver sends a warning signal to the timely activation of the prioritization function while driving 21st Attention is drawn to reliable charging of the tractor's traction battery 5 until reaching the destination Z to guarantee. With the help of the evaluation unit 35 becomes a switchover point in time during driving do or a correlated remaining distance STC estimated or determined. Until the determined changeover time do or from the remaining distance determined STC must use the prioritization function at the latest 19th activated so that when the route destination is reached Z at the destination time t _E a recharge of the tractor's traction battery 5 up to the intended target state of charge SOC _should is guaranteed.

In the 9 determines the evaluation unit 35 the changeover time do or the remaining distance STC on the basis of the state of charge difference ΔSOC, the intended target state of charge SOC setpoint _, the prioritization charge rate _{to be used in} the priority charging process C _P and a current average speed v over the distance covered so far Δs ( 7th ). The one in the evaluation unit 35 determined remaining distance STC will appear in the display 37 displayed. In this way, the driver receives an indication of the remaining distance from which the vehicle is driving STC the prioritization function 21st is to be activated with the achievement of the route target Z a recharge of the tractor's traction battery 5 up to the target state of charge SOC _should is guaranteed.

In the 5 is the energy management system when the fast charging function is activated 23 shown. The signal generating device generates accordingly 27 a trigger signal S _TS . When the quick charge function is activated 23 is in the 5 Take the tractor's traction battery, for example 5 can be charged with the highest possible charge rate Cs up to the highest possible charge level (100%), as shown in the charge state-time diagram of 8th is indicated. In the 8th becomes at the switchover time t _U the quick charge function 23 activated.

List of reference symbols

1

tractor

3

pendant

5

Tractor traction battery

7th

Trailer traction battery

9

Control device

10, 11, 12

Signal connections

15th

Distribution unit

17th

Accelerator pedal

19th

Basic function

21st

Prioritization function

23

Fast charging function

25th

Signal lines

27

Signal generation unit

29

Input unit

31

Investigation unit

33

Converter unit

35

Evaluation unit

37

Display unit

EM

Drive unit

E.

electrical power

HE

Recuperation energy

LE

Power electronics

FPS

Accelerator pedal position

S _T

Trigger signal

FB

Driving parameters

do

Changeover time

t _B

Start of journey time

t _E

Destination time

SOCz

The charge level of the tractor's traction battery

SOC _A

Charge level of the trailer traction battery

SOC _should

Target state of charge

C _P , C _S

Priority charge rate, fast charge rate

Z

Route target

STC

remaining distance

S _tot

Total driving distance

Δs

Distance covered up to the switchover time

v

Average driving speed

truck

Trucks

t

Travel time

Δl

Current value signal

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 2842814 B1 [0007]
• DE 102016010573 A1 [0007]

Claims (9)

Energy management system for an electrically powered truck (HGV) with a tractor (1) and a trailer (3), both of which are used to supply an electric drive unit (EM) of the tractor (1) with electrical energy (E), each with at least one tractor traction battery ( 5) and a trailer traction battery (7), the energy management system being assigned an electronic control device (9) which, when driving, uses signal connections (10, 11, 12) to control the tractor traction battery (5) and the trailer traction battery (7 ) and controls the electric drive unit (EM) for the electrical energy supply (E), and wherein the electronic control unit (9) has a distribution unit (15) by means of which on the basis of driving parameters (FB) and / or an accelerator pedal position (FPS) a distribution of electrical energy (E, E _R ) between the tractor traction battery (5), the trailer traction battery (7) and the electr omaschine (EM), characterized in that the control device (9), in particular when driving, can be switched between at least two energy management functions (19, 21, 23), by means of which the energy distribution in the distribution unit (15) can be carried out in different operating modes in order to specifically influence a state of charge (SOC _Z , SOC _A ) of the trailer traction battery (7) or the tractor's traction battery (5). Energy management system according to Claim 1 , characterized in that a switchover (tu) between the energy management functions (19, 21, 23) takes place through a manual driver-side input (29) in the electrical control device (9) or takes place automatically and independently of the driver on the basis of driving parameters (FB). Energy management system according to Claim 1 or 2 , characterized in that an energy management function is a basic function (19), when activated (S _TB ) the distribution unit (15), in particular a charge controller, the trailer traction battery (7) and the tractor traction battery (7) while driving uniformly discharges, in particular for the case that both the trailer traction battery (7) as well as the tractor traction battery (5) for driving start time (t _B) have equal states of charge (SOC _Z (t _b), SOC _A (t _B )), in particular are fully charged, and / or that when the basic function (19) is activated, both traction batteries (5, 7) are discharged with the same discharge curve over time (SOCz (t), SOC _A (t)) or with the same Discharge rate occurs. Energy management system according to Claim 1 , 2 or 3 , characterized in that an energy management function is a prioritization function (21), when activated (S _TP ) the distribution unit (15) closes one of the two traction batteries (5, 7) in driving mode when a route destination (Z) is reached a driving target time (t _e) to the highest possible target state of charge (SOC _soll), that is, charging particular 100%, with a Priorisier charging rate (C _P). Energy management system according to one of the preceding claims, characterized in that the energy management function is a fast charging function (23), when activated (S _TS ) the distribution unit (15) one of the two traction batteries (5, 7), when driving or during vehicle Standstill, immediately with the highest possible fast charging rate (Cs) up to the highest possible target state of charge (SOC _should ) of preferably 100%, and / or that in particular the fast charging rate (Cs) is larger than the priority charging rate (C _P ) the prioritization function (21). Energy management system according to one of the Claims 4 or 5 , characterized in that the control device (9) has an evaluation unit (35) by means of which a switching point in time (tu) or a correlated remaining distance (STC) can be estimated or determined during driving, up to or from The prioritization function (21) must be activated at the latest so that when the route destination (Z) is reached at the destination time (t _E ), the tractor's traction battery (5) or the trailer traction battery (7) can be charged up to the maximum target state of charge (SOC _soll) is ensured. Energy management system according to Claim 6 , characterized in that the evaluation unit (35) determines or estimates the switchover time (tu) or the remaining distance (STC) on the basis of the following parameters, namely the current state of charge (SOCz (t)) of the respective, for example from the driver prioritized traction battery (5), the target state of charge (SOC _soll), to be applied when the charging operation Priorisier Priorisierladerate (C _P) and the current average speed (v) on the far distance traveled (.DELTA.s). Energy management system according to one of the Claims 3 to 7th , characterized in that when the energy management functions are not activated, the control device (9) works with the basic function (19), so that from the time the journey begins (t _B ) the distribution unit (15) carries out energy distribution in accordance with the basic function (19) . Method for operating a heavy goods vehicle (HGV) by means of an energy management system according to one of the preceding claims.

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