WO2021123254A1

WO2021123254A1 - Predictive battery charging for battery-operated rail vehicles

Info

Publication number: WO2021123254A1
Application number: PCT/EP2020/087150
Authority: WO
Inventors: Dominik Anders; Fabian KLUMP; Heinz Flerlage
Original assignee: Bombardier Transportation Gmbh
Priority date: 2019-12-19
Filing date: 2020-12-18
Publication date: 2021-06-24
Also published as: EP4077039A1; DE102019135315A1

Abstract

The invention relates to a method for charging a traction battery of a battery-operated rail vehicle. The method comprises the step of determining a first expected energy consumption of the battery-operated rail vehicle for passing through a first route section without a charging point until reaching the next charging point. The method also comprises the step of determining a target state of charge of the traction battery, taking an aging status of the traction battery and the first expected energy consumption into consideration. The method also comprises the steps of adjusting a target temperature for the charging of the traction battery, and charging the traction battery until reaching the target state of charge. The invention also relates to a battery charging system for a battery-operated rail vehicle.

Description

description

Predictive battery charging for battery-powered rail vehicles

TECHNICAL AREA

The invention relates to a method for charging a traction battery of a battery-operated rail vehicle and a battery charging system for a battery-operated rail vehicle.

TECHNICAL BACKGROUND

[0002] When on duty, a rail vehicle typically runs on always defined and therefore recurring routes that are known in advance. The rail vehicle is predominantly fed by an external voltage source, for example by means of an overhead line of a power network, which can be connected to a current collector of the rail vehicle. During the traction of a rail vehicle, separation points or route sections without charging points, which means that no external power source is available, can occur. In order to be able to maintain the traction of the rail vehicle, alternative energy sources are required, such as diesel, hydrogen or a battery. A considerable amount of energy is required to maintain the traction of the rail vehicle and other devices of the rail vehicle, in particular of auxiliary operations, within a separation point, which places high demands on a traction battery for the rail vehicle.

PROBLEM STATEMENT

It is therefore the object of the present invention to provide a method for charging a traction battery of a battery-operated rail vehicle and a battery charging system for a battery-operated rail vehicle, with which an efficient operation of the traction battery is made possible, in particular within a charging point-free route section. SOLUTION IN ACCORDANCE WITH THE INVENTION

This object is according to claim 1 by a method for charging a

Detached the traction battery of a battery-operated rail vehicle. Furthermore, the object of providing a battery charging system for a battery-operated rail vehicle according to claim 14 is achieved. Further embodiments, modifications and improvements will become apparent from the following description and the appended claims.

According to one embodiment, a particularly predictive method for charging a traction battery of a battery-operated rail vehicle is provided. The method comprises the step of determining a first expected energy consumption of the battery-operated rail vehicle for driving through a first charging point-free route section until the next charging point is reached. The method also has the step of determining a target state of charge of the traction battery taking into account an aging state of the traction battery and the first energy consumption to be expected. The method has the steps of setting a target temperature for charging the traction battery and charging the traction battery until the target state of charge is reached.

According to a general aspect of the present disclosure, the steps of

Procedure can be carried out in any order. The step of charging the traction battery until the target state of charge is reached is preferably carried out last.

The T raktionsbatterie provides an energy store for feeding a T raktionseinrichtung the rail vehicle ready, but is not limited to it. The traction device typically comprises one or more electric motors. Furthermore, the traction battery can also provide an energy store for supplying auxiliary services, such as for example air conditioning or heating of the passenger compartment. Alternatively, the traction battery can only provide an energy store for feeding the traction device of the rail vehicle. In this case, the rail vehicle can have a vehicle battery for feeding the auxiliary services.

[0008] A battery-operated rail vehicle is to be understood as meaning a rail vehicle whose traction device can be fully fed by a traction battery. The battery-operated rail vehicle can be a purely battery-operated rail vehicle, but it can also be a rail vehicle, the traction device of which is fed by the traction battery in some sections of the route and by an external energy source, in particular by electricity taken from an overhead line, in other sections of the route.

Under "within a charging point" or "within a next charging point" both the lingering of the battery-powered rail vehicle at a location (for example a train station) where the traction battery can be charged, as well as driving through an extensive route in which the traction battery can be charged by an external energy source (e.g. energy from an overhead line) while driving. In the latter case, the traction battery is charged while the battery-powered rail vehicle is moving within the charging point (charging section). A "charging point-free route section" is a section without an external energy source for the rail vehicle.

The target state of charge is the state of charge (or SoC, "State of Charge") of the traction battery that the traction battery should have when entering the first section of the route without charging points.

The inventive method aims in particular to not fully charge the T raktionsbatterie as possible, but also not to operate in a very low state of charge, but to keep the state of charge of the traction battery in a range that leads to the lowest possible aging of the traction battery . For this purpose, the first expected energy consumption for driving through the first charging point-free route section is determined and based on this and taking into account the current state of aging of the traction battery, the target state of charge is determined. The target state of charge is determined in such a way that the energy provided by the traction battery is safely sufficient to drive through the first section of the route without charging points, but without unnecessarily charging the traction battery. The traction battery is preferably only charged until the target state of charge is reached and then no longer charged. As a result, the traction battery charged to the target state of charge has sufficient energy to feed the traction device, and in particular also the auxiliaries, but is, if possible, charged neither to a very high nor to a very low state of charge. The service life of the traction battery can advantageously be increased by the traction battery, if possible, not being charged to a very high state of charge, but rather being operated in a “medium range”. In more general terms, the Increase the performance of the traction battery both during charging and discharging by charging the traction battery to neither a very high nor a very low state of charge, but rather operating it in a "medium range".

The target state of charge does not necessarily have to correlate with the first energy consumption to be expected; in particular, the target state of charge can be significantly higher than the first energy consumption to be expected. For example, the first route section without charging points can be very short, and thus the first energy consumption to be expected can be very low. Determining the target state of charge of the traction battery taking into account the aging state of the traction battery and the first energy consumption to be expected will, in this example, lead to a significantly higher target state of charge than the first energy consumption to be expected. Instead, the target state of charge will be in a “medium range”.

The aging of the traction battery leads in particular to the fact that the capacity, i.e. the current maximum usable capacity, of the traction battery is reduced. One consequence of aging is that traction batteries with identical energy content but different aging states have different charging states. In other words, traction batteries with different aging states need different charging states in order to provide the same energy. The method according to the invention takes into account the state of aging when determining the target state of charge and therefore leads to a lower load on the traction battery in order to increase the overall service life of the traction battery and thus to save costs.

The method according to the invention further enables an improved recuperation capability of the battery in that a target state of charge adapted to the aging state is determined and a high state of charge is avoided. In particular, according to the present method, a significantly lower target state of charge is determined for newer or slightly aged traction batteries than for older or more heavily aged traction batteries, which significantly increases the service life of the traction battery and the performance of the traction battery both during charging and discharging.

Setting the target temperature for charging the traction battery enables the traction battery to be charged at a temperature at which the service life is influenced as little as possible, but the target state of charge is reached. The lifespan of the The traction battery decreases as the temperature rises, while the energy that can be supplied when charging the traction battery decreases significantly at low temperatures. Typically, the traction battery is operated in a temperature range of 15 to 35 ° C when charging. As a result, the cooling or heating power required to control the temperature of the traction battery should be reduced, but the traction battery should be operated in an optimal temperature range.

The method can furthermore have the step of determining a state of charge range (desired state of charge range) taking into account the aging state of the battery. The state of charge range is a range specific to the specifications of the traction battery and the aging state of the traction battery, in which the battery is advantageously operated in order to avoid maximum states of charge and to reduce signs of aging. However, as the state of aging of the traction battery increases, the charge state range to be taken into account increases, since the total capacity of the traction battery decreases and the capacity of the traction battery has to be used more and more. Both a minimum value of the required state of charge range are typically smaller and a maximum value of the required state of charge range is typically larger. A mean value of the state of charge range is often roughly in the middle of the total capacity in which the traction battery can be charged (entire SoC range), for example at 50% of the maximum state of charge of the traction battery. The target state of charge is set within the state of charge range. The traction battery is charged until the target charge level is reached, and thus within the charge level range.

The desired state of charge range is smaller than the maximum state of charge of the

Traction battery and above a final discharge voltage of the traction battery. The desired state of charge range can be less than 90% of the maximum state of charge of the traction battery and / or greater than 10% of the maximum state of charge of the traction battery, in particular for an older or more heavily aged traction battery. For a newer or slightly aged traction battery, the desired state of charge range can be significantly lower. For example, the state of charge range can be less than 65% of the maximum state of charge of the traction battery and / or greater than 35% of the maximum state of charge of the traction battery, in particular for a newer or slightly aged traction battery. The state of charge range can be dependent on a state of charge range, taking into account a state of charge range Service life and / or a state of charge range-dependent performance of the traction battery can be determined.

A typical loss of capacity over the aging of the traction battery is in the range of about 20 to 30%. When a traction battery is new, around 35% to around 65% SoC (i.e. around 30 to 40% DoD - Depth of Discharge) can be used and in the old state around 10% to around 90% SoC (i.e. around 80% DoD). According to one embodiment, it is provided that a new traction battery should not be discharged to below 35% SoC, and an aged battery is preferably operated in the range from 30% to 85%. This allows an additional reserve to be provided. At the same time, the aim is to maintain the symmetry of the operation (working around an average state of charge). In order to maintain the additional reserve even when the traction battery ages, provision can be made to shift the symmetrical operation to a rather asymmetrical operation without, however, completely giving up this.

According to one embodiment, the target state of charge is determined

Traction battery also taking into account a reserve factor, in particular for driving through the first section of the route without charging points until the next charging point is reached. The reserve factor serves in particular as a reserve for unplanned delays in the operational sequence and / or as a reserve for a possible failure of components. In the event of unplanned delays in the operational process, energy-optimized driving may not be possible. Taking the reserve factor into account enables traction and / or the auxiliary services to be maintained until the next charging point even if unforeseen events occur.

According to one embodiment, the target state of charge is determined

Traction battery also taking into account an expected energy consumption for tempering the traction battery when driving through the first charging point-free route section until the next charging point is reached. The energy consumption to be expected for controlling the temperature of the traction battery can be carried out taking into account the ambient temperature and / or the state of aging of the traction battery. The ambient temperature has an effect on the energy consumption to be expected for controlling the temperature of the traction battery, in particular since the energy consumption for cooling or heating the traction battery can depend significantly on the ambient temperature. The state of aging can also affect the expected energy consumption for controlling the temperature of the traction battery. An aged traction battery has a higher internal resistance and therefore requires a higher cooling capacity. The amount of energy required to control the temperature of the traction battery is typically considerably less than the amount of energy required to drive through the first section of the route without charging points until the next charging point is reached. The amount of energy required to control the temperature of the traction battery within the first section of the route without charging points is taken from the traction battery. The amount of energy required to control the temperature of the traction battery thus reduces the amount of energy available for driving through the first section of the route without charging points.

Typically, the traction battery is operated in a temperature range of about 15 to 35 ° C when discharging. Setting the target temperature for discharging the traction battery enables the traction battery to be discharged at high power while the service life is affected as little as possible. The service life of the traction battery decreases with increasing temperature, while the power that can be drawn when discharging the traction battery decreases at low temperatures. The temperature control is thus carried out in such a way that the lowest possible energy consumption for temperature control (cooling or heating) must be applied during discharging, but the traction battery is still not damaged or restrictions in the performance and service life of the action battery are minimized.

For example, the traction battery can be a lithium-ion battery. The

The internal resistance of a lithium-ion battery decreases with increasing temperature. This reduces losses, and a larger proportion of the chemically stored energy can be extracted. The traction battery can be heated or cooled depending on an ambient temperature and a load requirement on the traction battery. The cooling can take place by means of a compression refrigeration system. In cases in which a target temperature for the traction battery is well below the ambient temperature, the cooling requires significant energy consumption.

The setting of the target temperature for charging the traction battery can also make it possible to reduce the expected energy consumption for tempering the traction battery within the first charging point-free route section. In particular, during the charging of the traction battery, the traction battery can be increasingly cooled as the state of charge increases, for example to 27 ° C. at 35% SoC and to 23 ° C. at 85% SoC. The required amount of energy for the temperature control of the traction battery can be used within the first section of the route without charging points be reduced. In this way, the temperature of the traction battery is reduced during the charging process (i.e. energy is invested in cooling) and the temperature is increased during discharge (i.e. the energy required to cool the battery is saved). This is possible because a traction battery of 50kWh has a thermal capacity of approx. 0.1 to 0.2 kWh / K. This saves around 0.5 to 1 kilowatt hours when discharging, or, in other words, 1-2% DoD.

According to one embodiment, the target state of charge is determined such that the

When entering the next charging point, the charge level of the traction battery is within the charge level range (target charge level range). The charge status of the traction battery is advantageously within the charge status range during the entire journey within the first charging point-free route section. For example, the determination of the target state of charge can result in the target state of charge being within an upper range of the state of charge range, the state of charge of the traction battery being within a lower range of the state of charge range when the next charging point is reached.

In one embodiment, the first expected energy consumption is determined on the basis of an ambient temperature. The battery-operated rail vehicle can have a battery charging system that has a sensor for detecting the ambient temperature. Alternatively, for example, the ambient temperature can be transmitted to the battery charging system. The ambient temperature has an effect on the first expected energy consumption, in particular since the energy consumption of the auxiliary services, such as heating or air conditioning the passenger compartment, can depend significantly on the ambient temperature.

The first expected energy consumption can also be determined on the basis of a usage profile. The method further comprises determining the usage profile taking into account a route profile for the first route section free of charging points. The route profile shows the height differences and the distances within the first route section without charging points. The energy requirement for driving through the first section of the route without charging points can be estimated from the information on the height differences and the distances, taking into account the desired driving speeds and any acceleration and braking processes. The usage profile can be determined on the basis of various other factors. For example, the usage profile can also be determined taking into account a recuperation factor of the traction battery if the battery-operated rail vehicle is set up for regenerative braking or regenerative braking. The recuperation factor can mean that the first expected energy consumption is low or even negative, for example if the charging point is on a mountain and the first charging point-free route section corresponds to a downhill journey with a high proportion of braking. The usage profile can be determined taking into account external factors other than the ambient temperature. For example, the external factor can be a volume of traffic. An increased volume of traffic can lead to longer travel times and increase energy consumption, especially of the auxiliary services. The usage profile can, for example, also take into account a driving style of a vehicle driver. The first expected energy consumption can vary depending on the level of training of the locomotive driver on an energy-optimized driving style. The usage profile can also take into account a timetable. In the case of time reserves, the traction of the battery-operated rail vehicle can be carried out in an energy-optimized manner, and thus the first expected energy consumption can be reduced. In the event of a delay, an energy-inefficient driving style may be necessary and the first expected energy consumption may increase.

According to one embodiment, the method further comprises the step of determining a

Remaining time before entering the first section of the route without charging points. The remaining time is important for determining how long it takes to charge the traction battery until the target state of charge is reached. The method can furthermore have the step of creating a charging profile for reaching the target state of charge, taking into account the remaining time. Depending on the remaining time, a charging current can be adjusted so that the target state of charge is reached. For reasons of efficiency, the charging of the action battery can advantageously take place within a predetermined charging current range. In one embodiment, the charging profile is created in such a way that the charging current remains within the specified charging current range. In particular, a maximum charging current can be adapted to the available remaining charging time so that the target state of charge is reached. The charging current is preferably limited to a minimum so that, on the one hand, the remaining time is sufficient to bring the traction battery to the target state of charge and, on the other hand, the traction battery is charged as gently as possible. With increasing charging current, the damaging influence increases and leads to accelerated aging of the traction battery. In addition, limiting factors for the charging current, such as current limits for the overhead line, can be taken into account.

According to a general aspect, a journey of the battery-operated rail vehicle can include a series of charging points and route sections without charging points. In the following, embodiments are explained on the basis of a journey having two charging points and two route sections without charging points. These embodiments can be applied in a corresponding manner to journeys with three or more charging points and / or three or more charging point-free route sections. The naming of the route sections is chosen as follows: the charging point is followed by the first charging point-free route section, the first charging point-free route section is followed by the next charging point, this is followed by a second charging point-free route section, and this in turn is followed by the next but one charging point, and so on.

When driving with several charging points and several charging point-free

Route sections, the method can further include the step of determining a second expected energy consumption of the battery-operated rail vehicle for driving through a second charging point-free route section following the next charging point until the next but one charging point is reached. The determination of the second expected energy consumption of the battery-operated rail vehicle can take place in a manner corresponding to the determination of the first energy consumption to be expected of the battery-operated rail vehicle. This applies to all of the embodiments explained above, in particular with regard to the usage profile and / or the route profile, in relation to the determination of the first expected energy consumption of the battery-operated rail vehicle.

The method can furthermore have the step of determining a dwell time within the next charging point until the second charging point-free route section is driven into. The dwell time in the next charging point can be viewed as an analogue to the remaining time in the charging point, with the difference that the dwell time corresponds to a total duration of the battery-powered rail vehicle within the next charging point, while the remaining time is based on the assumption that the rail vehicle has already been within for some time of the charging point, the remaining time until leaving the charging point. For example, the method according to the invention could be carried out with a time delay after the charging point has been reached, or else that Procedure could be carried out before reaching the charging point. The determination of the second expected energy consumption and the dwell time already in the charging point can be particularly relevant if the dwell time is rather short and possibly not sufficient to charge the traction battery in such a way that sufficient energy is available for driving through the second section of the route without charging points. In particular, the dwell time can be too short to charge the traction battery within the specified charging current range.

It can therefore be advantageous when charging the traction battery in the charging point to provide a lead for driving through the second charging point-free route section.

The method can furthermore comprise the step of determining the target state of charge further taking into account the second expected energy consumption and the dwell time. This advantageously makes it possible for the traction battery to provide sufficient energy for driving through the second charging point-free route section even with a rather short dwell time.

In one embodiment, the target state of charge is determined in such a way that the state of charge of the traction battery is within the state of charge range when it enters the next but one charging point. This enables the charge status of the traction battery to be largely or even completely within the charge status range both in the first charging point-free route section and in the second charging point-free route section. The charging profile for reaching the target state of charge can be created taking into account the remaining time and the length of stay. The charging profile can be set in such a way that the charging current remains within a predetermined charging current range both in the charging point and in the next charging point.

The method can further comprise detecting the state of charge of the traction battery. The battery charging system can, for example, have a sensor for detecting the state of charge of the traction battery. From the difference between the target state of charge and a current state of charge of the traction battery, the amount of energy required to achieve the target state of charge can be determined.

According to one embodiment, a battery charging system for a battery-operated rail vehicle is provided. The battery charging system has a traction battery for operating the rail vehicle and a control unit. The control unit is set up for a first expected energy consumption of the battery-operated one To determine rail vehicle for driving through a first charging point-free route section until reaching the next charging point. Furthermore, the control unit is set up to determine a target state of charge of the traction battery, taking into account an aging state of the traction battery and the first energy consumption to be expected. The control unit is configured to set a target temperature for charging the traction battery and to control the charging of the traction battery until the target state of charge is reached.

The control unit can be set up to all of the above disclosed

Execute embodiments in connection with the method according to the invention. In particular, the control unit can be set up to measure the reserve factor and / or the ambient temperature and / or the usage profile and / or the state of charge range and / or the route profile and / or the remaining time and / or the dwell time and / or the second expected energy consumption and / or to determine the charging current and / or the charging current range. The control unit can have a computing unit for determining the aforementioned components. For example, the computing unit can have a data memory with map data for determining the route profile. The battery charging system can have a sensor for detecting the state of charge of the traction battery. The control unit can be set up to determine a required amount of energy from the difference between the target state of charge and a current state of charge of the traction battery and to control the charging of the traction battery until the target state of charge is reached.

To this end, the control unit can be set up below a state of charge range

To take into account the aging condition of the traction battery to determine, and to determine the target state of charge within the state of charge range.

The battery charging system can also include a sensor for detecting the

Have ambient temperature. The control unit can be set up to determine the first expected energy consumption on the basis of the ambient temperature and a usage profile and to obtain the usage profile taking into account a route profile within the first route section without charging points.

The control unit can also be configured to determine a remaining time until the first charging point-free route section is entered and configured to include a To determine the charging profile for reaching the target state of charge, taking into account the remaining time.

According to one embodiment, a rail vehicle is provided. The

Rail vehicle has a battery charging system according to one of the embodiments disclosed herein.

CHARACTERS

[0041] The invention is explained in more detail below on the basis of embodiments, without these being intended to restrict the scope of protection defined by the claims.

The accompanying drawings illustrate embodiments and, together with the description, serve to explain the principles of the invention. The elements of the drawings are relative to one another and not necessarily to scale.

Figure 1 shows schematically a time profile of a charge state of a traction battery within the charging point and within the first charging point-free route section.

FIG. 2 schematically shows a time profile of a state of charge of a traction battery within the charging point, within the first charging point-free route section, within the next charging point, and within the second charging point-free route section.

Figure 3 shows the state of charge range of a new traction battery.

FIG. 4 shows the state of charge range of an aged traction battery.

EXEMPLARY EMBODIMENTS

FIG. 1 schematically shows a time profile of a state of charge (SoC) of a

Traction battery when driving on a route section that includes a charging point and a first route section without charging points. The horizontal, dotted lines represent a minimum and a maximum value of a desired state of charge range in which the traction battery should preferably be operated, to reduce the aging of the traction battery. The vertical dotted line highlights the transition between the charging point and the first section of the route without charging points.

[0044] The target state of charge shown is the state of charge of the traction battery at the time of entering the route section without charging points. The charging point can designate a place where the rail vehicle stays for charging, or an electrified route section that the rail vehicle travels through.

At the beginning of a remaining time in the charging point, the charging status of the traction battery is within the charging status range, but not sufficiently high to drive through a first charging point-free section of the route until the next charging point is reached. For example, the rail vehicle can be located in an electrified section of the entire route. For example, the charge status of the traction battery is constantly monitored. With the method according to the invention, it is now anticipated how much energy is required for the section of the route without charging points to be traveled in order to start charging the traction battery in good time without excessive charging currents being required.

Since rail vehicles are manufactured by the manufacturer in accordance with customer requirements, it can be assumed that the total capacity of the traction battery is basically high enough to provide the required energy. The easiest way would be to always charge the traction battery to the maximum, as this ensures that there is always enough energy available. However, constant charging up to the maximum state of charge leads to increased aging of the traction battery, as a result of which the maximum capacity provided by the traction battery drops rapidly.

The aim of the method according to the invention is to avoid this. The aim is to operate the traction battery in a “medium” range (charging and discharging) in which the load on the traction battery is comparatively low. This middle area is referred to as the target state of charge area. In the case of new traction batteries, where the maximum capacity is very high, the target state of charge range can be selected to be comparatively narrow. With increasingly decreasing capacity due to aging, on the other hand, the target state of charge range must be chosen to be larger and larger so that the same amount of energy can be accessed. The method according to the invention therefore avoids especially with new traction batteries that they are subject to accelerated aging due to a high state of charge.

In the figure 3 the desired state of charge range for a new traction battery is shown. Since the total capacity is still very high, the state of charge range can still be selected to be relatively narrow in contrast to a traction battery that has been in operation for a long time. Their state of charge range is shown in FIG. The state of charge range for both traction batteries covers the same energy content. Due to the reduced total capacity due to aging, however, the range of use of the traction battery in FIG. 4 must be expanded.

The state of charge range selected as a function of the aging state can also be referred to as the desired state of charge range.

There is initially an estimate of a first expected energy consumption of the battery-operated rail vehicle for driving through the first charging point-free route section until the next charging point is reached. The first expected energy consumption should include the total consumption, i.e. in particular the energy consumption for traction taking into account current requirements from the timetable, consumption by auxiliary equipment, e.g. air conditioning, as well as safety surcharges for any unexpected events, e.g. unscheduled stops or delays.

For the energy consumption for traction, the route profile (heights,

Climbs, route length, descents) as well as the desired driving speeds for the individual sections within the route profile are important. Scheduled stops must also be taken into account. In addition, the individual driving behavior of the rail vehicle driver and current timetable requirements can also be taken into account.

In addition, the energy requirement for air conditioning and, for example, lighting is estimated. To do this, the outside temperature can be determined and the lighting conditions taken into account.

Finally, air conditioning is also required for operating the traction battery in order to keep its temperature in an optimal range. In addition, the recuperation factor can be taken into account, which is also influenced in particular by the route profile and the braking processes to be expected.

In addition, a reserve factor is taken into account.

All in all, a usage profile for the first charging point-free route section results, which is determined for the estimation of the first energy consumption to be expected.

Furthermore, a desired state of charge range is defined, which was determined as a function of the aging state of the action battery. The desired state of charge range is intended to avoid excessive stress on the traction battery.

After the first expected energy consumption has been determined, the traction battery is charged in the charging point in such a way that the charging state of the traction battery is sufficient for driving through the first charging point-free route section until the next charging point is reached. The target state of charge is set within the desired state of charge range. The target state of charge is also determined in such a way that the state of charge of the traction battery is still within the state of charge range even when entering the next charging point. This avoids maximum states during loading and unloading.

For a further improvement, the charging takes place at a temperature which is only slightly stressful for the traction battery. At this temperature the battery can be charged efficiently. At higher temperatures, a traction battery, especially if it is a lithium-ion battery, can be charged more quickly and with lower internal losses, but this leads to a greater load on the traction battery. Therefore, the temperature is set so that charging is efficient, but only results in a low load on the traction battery and the energy consumption for temperature control is low. Temperatures between 15 - 35 ° C are favorable.

FIG. 2 schematically shows a time profile of a state of charge (SoC) of a

Traction battery when driving in a route section which comprises a charging point, a first charging point-free route section following the charging point, a next charging point following the first charging point-free route section, and a second charging point-free route section following this. The horizontal, dotted lines represent a minimum and a maximum value of a The vertical dotted lines highlight the transitions between the respective route sections.

The target state of charge shown is the state of charge of the traction battery at the time of entering the route section without charging points.

In this embodiment, not only the first charging point-free route section but also further sections are taken into account, because the traction battery must also provide sufficient energy for driving through the second charging point-free route section. If the dwell time at the next charging point, i.e. before entering the second section of the route without charging points, is sufficiently long, there would be enough time for charging. However, if the dwell time at the next charging point is only short, the dwell time alone is not sufficient to charge the traction battery for driving through the second section of the route without charging points. Therefore, when charging the traction battery in the (first) charging point, both the energy consumption for driving through the first and second charging point-free route section (first expected energy consumption and second expected energy consumption) as well as partial charging during the stay at the next charging point must be taken into account.

At the beginning of a remaining time at the charging point, the charging status of the traction battery is within the desired charging status range, but not sufficient for driving through a first charging point-free route section until the next charging point is reached.

In addition, a second expected energy consumption of the battery-operated rail vehicle for driving through the second charging point-free route section until reaching the next but one charging point and a dwell time within the next charging point until entering the second charging point-free route section have been determined. However, the time spent at the next charging point is too short to sufficiently charge the traction battery for the second section of the route without charging points.

The target state of charge has therefore been determined taking into account the first expected energy consumption, the second expected energy consumption and the dwell time. In particular, the traction battery has been charged in the charging point in such a way that there is sufficient energy for the second section of the route without charging points is available. The target state of charge has been determined in such a way that the state of charge of the traction battery when entering the next but one charging point is within the state of charge range.

Although specific embodiments have been shown and described herein, it is within the scope of the present invention to modify the shown embodiments as appropriate without departing from the scope of the present invention.

Claims

Expectations

1. A method for charging a traction battery of a battery-operated rail vehicle, comprising:

Determining a first expected energy consumption of the battery-operated rail vehicle for driving through a first route section without charging points until a next charging point is reached; and

Determining a target state of charge of the traction battery taking into account an aging state of the traction battery and the first expected energy consumption; and

Setting a target temperature for charging the traction battery; and charging the traction battery until the target state of charge is reached.

2. The method of claim 1, further comprising:

Determining a state of charge range taking into account the aging state of the traction battery, the target state of charge being established within the state of charge range.

3. The method according to any one of the preceding claims, wherein the state of charge range is smaller than the maximum state of charge of the traction battery and above a complete state of discharge of the traction battery, in particular wherein the state of charge range is less than 90% of the maximum state of charge of the traction battery and / or greater than 10% of the maximum Is the charge level of the traction battery.

4. The method according to any one of the preceding claims, wherein determining the first expected energy consumption based on an ambient temperature and a Usage profile that is obtained taking into account a route profile within the first route section without charging points.

5. The method according to claim 4, wherein the route profile comprises the height differences within the first charging point-free route section, the distance to the next charging point, and the number of stops within the first charging point-free route section.

6. The method according to any one of the preceding claims, wherein the target state of charge is further determined taking into account a reserve factor.

7. The method according to any one of the preceding claims, further comprising:

Determining a remaining time before entering the first charging point-free route section; and

Creation of a charge profile to reach the target charge level, taking into account the remaining time.

8. The method according to claim 7, wherein the charging profile is created in such a way that a charging current remains within a predetermined charging current range, in particular that a charging current that only loads the traction battery is set.

9. The method according to any one of the preceding claims, further comprising:

Determination of a second expected energy consumption of the battery-operated rail vehicle for driving through a second charging point-free route section following the next charging point until the next but one charging point is reached; and

Determining a dwell time within the next charging point until the vehicle enters the second charging point-free route section; and Determining the target state of charge also taking into account the second expected energy consumption and the dwell time.

10. The method according to any one of the preceding claims, wherein the target state of charge is determined such that the state of charge of the traction battery when entering the next charging point is within the state of charge range.

11. The method according to any one of the preceding claims, wherein the target state of charge is determined in such a way that the state of charge of the traction battery is within the state of charge range when entering the next but one charging point.

12. The method according to any one of the preceding claims, wherein the target state of charge is further determined taking into account an expected energy consumption for tempering the traction battery when driving through the first charging point-free route section until the next charging point is reached.

13. The method according to any one of the preceding claims, wherein the state of charge range is determined taking into account a state of charge range-dependent service life and / or a state of charge range-dependent power of the traction battery.

14. A battery charging system for a battery-operated rail vehicle, comprising: a traction battery for operating the rail vehicle, a control unit which is set up to: determine a first expected energy consumption of the battery-operated rail vehicle for traveling through a first charging point-free route section until the next charging point is reached; and determine a target state of charge of the traction battery taking into account an aging state of the traction battery and the first expected energy consumption; set a target temperature for charging the traction battery; and to control the charging of the traction battery until the target charge level is reached.

15. The battery charging system according to claim 14, wherein the control unit is set up to determine a state of charge range, taking into account the state of aging of the traction battery, and to determine the target state of charge within the state of charge range.

16. Battery charging system according to one of claims 14 and 15, further comprising a sensor for detecting the ambient temperature, wherein the control unit is set up to determine the first expected energy consumption on the basis of the ambient temperature and a usage profile, and the usage profile is configured taking into account a Route profile within the first section of the route without charging points.

17. Battery charging system according to one of claims 14 to 16, wherein the control unit is further configured to determine a remaining time until entering the first charging point-free route section and is configured to determine a charging profile for reaching the target state of charge taking into account the remaining time.