Charging strategy

Abstract

A method for determining and optionally additionally implementing an optimal route for a vehicle that has an electrical drive system having an energy storage device, and a converter to charge the energy storage device.

Claims

1. A method for determining an optimal route for a vehicle having a control unit having logic, an electrical drive system with an energy storage device, and a converter to charge the energy storage device, and which is operated via a fuel, the control unit being configured to perform the method comprising: providing a destination for the vehicle; determining one or more possible routes from a current position of the vehicle to the destination, wherein the one or more routes is/are determined in dependence upon a geographical position of refueling stations for the fuel and electric charging stations in the region between the current position and the destination; setting an optimal route via selecting from the determined one or more possible routes; and implementing the optimal route via expediently operating the converter to charge the energy storage device when driving along the optimal route, wherein if the optimal route is a route that is optimized for use of a refueling station, the optimal route is implemented in such a manner that a level of intensity of use of the converter is maximized so that a fill level of fuel is as low as possible when reaching the refueling station.

2. The method of claim 1, wherein the converter is a fuel cell.

3. The method of claim 2, wherein the fuel comprises hydrogen.

4. The method of claim 1, wherein the one or more possible routes comprises at least one route that is optimized for use of refueling stations for the fuel.

5. The method of claim 1, wherein the one or more possible routes comprises at least one route that is optimized for use of electric charging stations.

6. The method of claim 1, wherein the one or more possible routes comprise: at least one route that is optimized for use of refueling stations for the fuel; and at least one route that is optimized for the use of electric charging stations.

7. The method of claim 1, further comprising visually displaying, to a user of the vehicle, the determined at least one possible routes.

8. The method of claim 1, further comprising visually displaying, to a user of the vehicle, a recommended route from the determined at least one possible routes.

9. The method of claim 1, further comprising visually displaying, to a user of the vehicle, at least one route that is optimized for use of refueling stations for the fuel.

10. The method of claim 9, further comprising visually displaying, to a user of the vehicle, at least one route that is optimized for use of electric charging stations.

11. The method of claim 1, wherein the optimal route is manually selected from the determined routes by the user.

12. The method of claim 1, wherein the one or more possible routes are determined in dependence upon a prevailing state of charge of the energy storage device.

13. The method of claim 1, wherein the one or more possible routes are determined in dependence upon a prevailing fill level of fuel.

14. The method of claim 1, wherein the one or more possible routes are determined in dependence upon a prevailing state of charge of the energy storage device and the prevailing fill level of fuel.

15. The method of claim 1, wherein the one or more possible routes are determined in dependence upon emissions requirements at the destination.

16. The method of claim 1, wherein the optimal route is implemented in such a manner that, after reaching the destination, the converter is operated in order to charge the energy storage device.

17. A vehicle, comprising: an electrical drive system having an energy storage device; a converter to charge the energy storage device, and which is operated via a fuel; and a control unit having logic, at least partially comprising hardware configured to: provide a destination for the vehicle; determine one or more possible routes from a current position of the vehicle to the destination, wherein the one or more routes is/are determined in dependence upon a geographical position of refueling stations for the fuel and electric charging stations in the region between the current position and the destination; set an optimal route via selecting from the determined one or more possible routes; and implement the optimal route via expediently operating the converter so as to charge the energy storage device when driving along the optimal route, wherein: if the optimal route is a route that is optimized for use of a refueling station, the optimal route is implemented in such a manner that a level of intensity of use of the converter is maximized so that a fill level of fuel is as low as possible when reaching the refueling station, and if the optimal route is a route that is optimized for use of electric charging station, the optimal route is implemented in such a manner that a level of intensity of use of an electrical drive system of the vehicle is maximized so that a state of charge of the energy storage device is as low as possible when reaching an electric charging station.

18. A method for operating a vehicle having a control unit having logic, the control unit being configured to perform the method comprising: providing a destination for the vehicle; determining, from a current position of the vehicle to the destination, one or more possible routes in dependence upon a geographical position of refueling stations for fuel for the vehicle and electric charging stations for the vehicle in the region between the current position and the destination; setting an optimal route via selecting from the determined one or more possible routes; and implementing the optimal route by expediently operating a converter to charge an energy storage device of an electrical drive system of the vehicle when driving along the optimal route, wherein if the optimal route is a route that is optimized for use of an electric charging station, the optimal route is implemented in such a manner that a level of intensity of use of the electrical drive system is maximized so that a state of charge of the energy storage device is as low as possible when reaching an electric charging station.

Description

DRAWINGS

(1) Embodiments will be illustrated by way of example in the drawings and explained in the description below.

(2) FIG. 1 illustrates schematically an optimal route that may be determined and implemented via a method in accordance with embodiments.

(3) FIG. 2 illustrates schematically an alternative optimal route that may be determined and implemented via a method in accordance with embodiments.

(4) FIG. 3 illustrates schematically a procedure diagram of a method for determining and implementing an optimal route for a vehicle, in accordance with embodiments.

(5) FIG. 4 illustrates schematically a vehicle, in accordance with embodiments.

DESCRIPTION

(6) FIGS. 1 and 2 illustrate schematically two possible optimal routes that may be determined and implemented via a method in accordance with embodiments.

(7) The method in accordance with embodiments is explained with reference to a fictitious route distance F. A fuel cell that is operated as a converter of the vehicle using, for example, hydrogen (H.sub.2) is provided.

(8) In operation, a driver of the vehicle would like to travel the route distance F between a first specific destination, e.g., Munich central station, as a starting position and current position A and a second specific destination, e.g., Karlsruhe central station as the destination Z. Since the range of the vehicle is not sufficient to cover the entire distance of the route distance F, it is necessary to refuel with hydrogen or electrical energy. In the example, for this purpose, there is a refueling station TW for refueling with hydrogen between Munich and Karlsruhe 204 km after S, in other words Munich. If the vehicle travels to this refueling station, the entire journey to the destination Z, Karlsruhe central station, becomes 306 km. Moreover, there is an electric charging station TS in Stuttgart 218 km after the start point S in Munich. When travelling to this electric charging station TS, an entire journey to the destination becomes 294 km.

(9) As a result, the method in accordance with embodiments proposes to the driver two determined routes that prioritize the two refueling possibilities differently. In other words, determining the routes based upon the two possible energy forms for operating the drive system. The selection of the optimal route that is finally to be implemented may be done manually, for example, by the driver. The first route that is determined prioritizes refueling with hydrogen and is illustrated in FIG. 1. The second route that is determined prioritizes charging with electricity and is illustrated in FIG. 2.

(10) The route that is illustrated in FIG. 1 and prioritizes refueling with hydrogen is determined via the method in accordance with embodiments in such a manner that said route is optimized so as to render it possible to refuel with hydrogen as much as possible at the hydrogen refueling stations that are present in the region between the starting point and the destination in order to achieve a maximum range of the vehicle. The energy storage device of the electrical drive system is used as a buffer storage device in order to temporarily store the energy of the hydrogen. As complete as possible a refueling of hydrogen is to be rendered possible if a hydrogen refueling station is located within the range of the vehicle.

(11) For this purpose, in a first time period, the vehicle only drives by way of the electrical drive, and the fuel cell is not operated or remains deactivated.

(12) In a subsequent second time period, initially the fuel cell is operated using a lower or minimal power that is required for the drive of the vehicle and possible additional units so that the stored energy of the electrical drive (Battery SOC) remains at a constant level.

(13) In a subsequent third time period, the fuel cell is operated using a higher power than is required for driving the vehicle and possible additional units and the rest of the energy obtained from the hydrogen is used to charge the electrical energy storage device.

(14) When arriving at the hydrogen refueling station TW, the hydrogen tank is empty so that the tank may be refueled with as much hydrogen as possible, namely the entire hydrogen tank volume (H2 SOC). The electrical storage device (Battery SOC) completely is charged via the preceding charging procedure by way of the fuel cell when reaching the hydrogen refueling station TW. The transitions between the time periods are determined in such a manner that at the planned intermediate station hydrogen refueling station TW the hydrogen tank is empty (H2 SOC) and the electrical energy storage device (Battery SOC) are fully charged as much as possible. After leaving the hydrogen refueling station TW, only electrical energy is used to drive the vehicle to the destination Z and the fuel cell is not operated since a hydrogen refueling station is not available at the destination.

(15) If the destination Z has been reached with a low electrical state of charge (Battery SOC) and an external charging procedure is not possible by way of an electric charging station, the vehicle offers the function of an emission free charging procedure of the electrical storage device via the hydrogen drive. The charging procedure may be performed in the parked state P anywhere, even in enclosed spaces. At the start of the next journey, the driver is to have a sufficiently high battery state of charge (Battery SOC).

(16) In the case of the route that is illustrated in FIG. 2 and prioritizes electrical recharging, the route distance F is selected by a method in accordance with embodiments in such a manner that the electrical battery is empty at a defined electric charging station TS as an intermediate station or preferably the state of charge (Battery SOC) is at a defined lower threshold value in order to render possible a maximum recharging of the electrical current.

(17) For this purpose, in a first time period the vehicle is driven electrically without operating or activating the fuel cell.

(18) Subsequently, in a second time period, the hydrogen drive system is used in order to charge the electrical energy storage device of the electrical drive (Battery SOC) during the journey, so that it is at all possible to reach the intermediate station electric charging station TS.

(19) When reaching the electric charging station TS, the electrical state of charge (Battery SOC) is at a defined minimum threshold value, the hydrogen tank (H2 SOC) is in part emptied and cannot be currently refueled. Electrical current may be recharged at the electric charging station TS. After leaving the electric charging station TS, the vehicle is driven exclusively by the electrical drive, the fuel cell is not operated. When reaching the destination Z, the electrical energy storage device (Battery SOC) may be recharged, by way of example, via a current-charging possibility at the destination car park Z. If such a charging possibility is not present, the fuel cell can also be operated at a standstill in order to raise the state of charge of the energy storage device.

(20) If the driver selects the route of refueling with hydrogen (FIG. 1), the route distance increases by 12 km. However, the vehicle is refueled with hydrogen in a few minutes. If the route of charging with electricity (FIG. 2) is selected, the total distance reduces to 294 km. However, the journey time increases by the charging time that can last multiple hours depending upon the charging type and the charging power of the battery. The user of the method in accordance with embodiments may therefore select between these two prioritizations and where appropriate can select a longer route so as to achieve a shorter journey time.

(21) FIG. 3 illustrates a procedure diagram of a method in accordance with embodiments for determining and implementing an optimal route for a vehicle.

(22) In dependence upon the energy that is available (Battery State of Charge and H2 tank State of Fill Level), and thereby, the range that the vehicle can travel (Max Range H2, Max Range Electric, Total Range), and also the destination (Driver request navigation destination) and therefore route length, duration of journey (distance, duration) and possibly the refueling possibilities that are available on the route or at the destination (Refueling and charge possibility on route), the method that is illustrated in accordance with embodiments decides initially regarding the necessity of using a route-based charging strategy (FIG. 3, left-hand side lower region) on the basis of the question whether the destination may be reached without a refueling procedure. If a route based charging strategy is not necessary since the fuel that is present is sufficient to reach the destination and also a sufficient recharging procedure of electrical current and/or hydrogen is possible at the destination for the subsequent operation, the normal non route-related operating strategy (normal charging strategy) that is implemented in the vehicle is used for implementing the route, in other words the operating strategy that is not dependent upon the positions of possible charging/refueling stations (FIG. 3 right-hand side lower region).

(23) If, however, by way of example, the destination of the navigation for the prevailing range of the vehicle is too far away or there are no charging possibilities or refueling possibilities at the destination, the route-based charging strategy is selected and therefore possible routes are determined in dependence upon the geographical position both of refueling stations for the hydrogen as well as electric charging stations in the region between the current position and the destination (FIG. 3 upper left-hand side region).

(24) Taking into account the calculated total journey time (Duration of route), the availability and positions of the potential charging possibilities/refueling possibilities (Refuel stations) and also the calculated energy costs (Energy costs), this provides a route recommendation and/or a route that prioritizes both a hydrogen refueling procedure and also an electrical recharging procedure to the driver for selection from (Route recommend, Route H2 refueling, Route electric charging).

(25) When the selection is made manually (e.g., via Driver request) by the driver, the route is transferred to the navigation system (Navigation) and the charging strategy that is calculated for this purpose for implementing the route is transmitted to the operating strategy (Operating Strategy) (FIG. 3, right-hand side region).

(26) FIG. 4 illustrates schematically a vehicle 10 having an electrical drive system 20 with an energy storage device 30, and a fuel cell 40 that operates as a converter to charge the energy storage device 30.

(27) The term coupled, or attached, or connected may be used herein to refer to any type of relationship, direct or indirect, between the components in question, and may apply to electrical, mechanical, fluid, optical, electromagnetic, electromechanical or other connections. In addition, the terms first, second, etc. are used herein only to facilitate discussion, and carry no particular temporal or chronological significance unless otherwise indicated.

(28) This written description uses examples to disclose the invention, including the preferred embodiments, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of embodiments is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. Aspects from the various embodiments described, as well as other known equivalents for each such aspects, may be mixed and matched by one of ordinary skill in the art to construct additional embodiments and techniques in accordance with principles of this application.

LIST OF REFERENCE SIGNS

(29) F Route distance

(30) P Parking time

(31) A Starting position, current position

(32) Z Destination

(33) TW Hydrogen refueling station

(34) TS Electric charging station

(35) SOC State of charge

(36) 10 Vehicle

(37) 20 Electrical drive system

(38) 30 Energy storage device

(39) 40 Fuel cell/converter