AU2010256020B2

AU2010256020B2 - Energy-saving operation of rail vehicles having at least two drive units

Info

Publication number: AU2010256020B2
Application number: AU2010256020A
Authority: AU
Inventors: Stefan Lauer; Jens Rasche
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2009-06-03
Filing date: 2010-02-16
Publication date: 2014-08-14
Anticipated expiration: 2030-02-16
Also published as: RU2520626C2; EP2437968A1; DE102009024146A1; ES2731639T3; CN102803042B; WO2010139489A1; AU2010256020A1; EP2437968B1; PL2437968T3; CN102803042A; RU2011154365A

Abstract

The invention relates to a method for controlling the drive of a rail vehicle, comprising a drive having a plurality of drive units, wherein the drive units are connected to the drive or disconnected therefrom such that the sum of the traction forces of the drive units is greater than the required tractive force, thus lowering the energy consumption. According to the invention, the required tractive force is calculated depending on the route for partial sections of the route, and the number of activated drive units is changed during driving and is adapted to the required tractive force.

Description

PCT/EP2010/051879 - 1 2009P09576WORU Description Energy-saving operation of rail vehicles having at least two drive units The invention relates to a method for controlling the drive of a rail vehicle which has a drive comprising a plurality of drive units, in which the drive units are connected to the drive or disconnected therefrom such that the sum of the traction forces of the drive units is greater than the required tractive force. The invention also relates to a rail vehicle comprising a drive which has at least two drive units, and a control unit which is connected to the drive and which is configured to switch the drive units on and off. Such a method and such a rail vehicle are already known from the prior art. For example, in particular in goods railway operations double locomotives are known in which the necessary traction force is made available by two component locomotives or in other words drive units. If a large tractive force is necessary, for example given a heavy load and to a specific extent steep gradient of the route, the two component locomotives remain continuously switched on even if the large tractive force is required only on a small part of the overall route. The previously known method and the previously known rail vehicle therefore have the disadvantage that the operation of the two component locomotives results in high energy consumption, which entails high operating costs.

2 It is an object of the invention to improve upon the prior art at least to an extent or to provide an alternative thereto. A preferred embodiment aims to make available a method and a rail vehicle of the type mentioned at the beginning such that the energy consumption can be lowered. There is disclosed herein a method for controlling the drive of a rail vehicle which has a drive comprising a plurality of drive units, in which the drive units are connected to the drive or disconnected therefrom such that the sum of the traction forces of the switched-on drive units is greater than the required tractive force, wherein the required tractive force is calculated as a function of the route for sections of the route, and the number of switched-on drive units during travel is changed and adapted to the respectively required tractive force, wherein at the specific points on the route the respective operating point of the rail vehicle is determined, an efficiency level is calculated for the determined operating point for each number of drive units which can be switched on, the efficiency levels which can be determined in this way are compared with one another by acquiring an optimum efficiency level, and subsequently so many drive units are switched on that their number corresponds to the number of drive units which are assigned to the optimum efficiency level; and wherein the efficiency levels are determined both with respect to the feedback capability in a braking mode and with respect to the traction force which can be generated. According to an embodiment, an environmentally friendly rail vehicle with double traction or multiple traction is proposed. For this purpose, the rail vehicle has at least two drive units which can be switched on and off during travel such that the number of the operated drive units can be changed. The drive units are switched on and off in such a way that the lowest possible consumption of energy occurs. The disclosure is based 3 on the idea that multiple traction which can be applied in principle should take place only when absolutely necessary owing to the required tractive force. The necessary tractive force is, on the one hand, dependent on the route profile and on the load state of the rail vehicle and can be determined with methods which are known to a person skilled in the art, for example by means of a simulation. The simulation requires, as input variable, for example the route profile and the load state of the rail vehicle, the temperature and the like. In the rail vehicle according to the invention, means are provided for making available the required tractive force. These means access the determined data of the tractive force as a function of the location, with the result that the tractive force which is required at this location is available to the rail vehicle for the respective point on the route. If it is detected within the scope of the invention that the required tractive force can be made available in a section of the route by only one drive unit, the drive units which are not required can be switched off. In this way, the consumption of electrical energy by the rail vehicle is reduced, in particular also by the omission of part of the auxiliary operating energy. The operating costs of the rail vehicle are therefore also decreased. Moreover, the drive units which are switched off are loaded to a lesser degree. According to one preferred embodiment, the required tractive force is calculated with spatial resolution before the start of travel. On the basis of the sufficiently precisely detected route and the outer peripheral conditions of the travel, in particular of the route profile, the tractive force can be calculated in such a way in advance. As a result of this calculation, the required tractive force is obtained in advance as a function of specific route points. In this context there is no need whatsoever to carry out the calculation in the rail 4 vehicle itself. The calculation can also be carried out outside the rail vehicle at an external location, for example in a control center, wherein the results of the calculation are subsequently transmitted to the rail vehicle, for example by means of radio transmissions, WLAN or the like. The rail vehicle receives the transmitted data and stores them, with the result that any desired expedient access to the data during travel is made possible. Advantageously the number of switched-on drive units at specific points on the route is changed. The points on the route are marked, for example, on the roadway such that the switching on and off of the drive units can be carried out manually by the driver of the locomotive. In contrast to this, electrical or inductive marks in the form of beacons or the like are arranged at the points on the route such that the rail vehicle can automatically monitor for when a point on the route is reached, without intervention by a train driver. It is also possible to use satellite-supported locating methods, such as GPS or the like, within the scope of the disclosure. Furthermore, it is advantageous if the required tractive force is calculated for each point on the route, and subsequently at least so many drive units are switched on that the sum of the traction forces of the switched-on drive units is greater than the required tractive force. This development ensures again that a sufficiently large tractive force is always made available at each point on the route, such that the rail vehicle can continue its travel in all cases. According to one expedient development in this respect, at the specific points on the route the respective operating point of the rail vehicle is determined, an efficiency level is calculated for the determined operating point and for each number of drive units which can be switched on, the efficiency 5 levels which can be determined in this way are compared with one another by acquiring an optimum efficiency level, and subsequently so many drive units are switched on that their number corresponds to the number of drive units which are assigned to the optimum efficiency level. According to this preferred refinement, for reasons of optimum energy consumption more drive units are switched on at specific sections than are necessary to make available the required tractive force. This is based on the realization that the efficiency level of the drive can be more favorable if more drive units than necessary are switched on. Efficiency level is understood here to be the proportion of the acquired traction energy related to the electrical energy used. The efficiency level of the drive is dependent on various influencing parameters. For example, the components of the drive units, such as for example the main transformer, power converter, traction motor, transmission and the like, have different efficiency levels in different working ranges. The efficiency level of the traction motor varies, for example, with the speed of the rail vehicle. Therefore, an operating point of the rail vehicle must firstly be determined before the efficiency level can be determined. The operating point describes the state of the rail vehicle. This state is described by the speed of the rail vehicle, the external temperature, the gradient of the route, the number of wagons of the rail vehicle and their loading, the selective ventilation, the friction and the like. The operating point is defined by this information. The efficiency levels of the individual drive components are stored in table form for specific regions. The overall efficiency level of the respective drive unit is composed of these individual efficiency levels of their components and can be calculated by simple multiplication. The respective operating points and the efficiency levels which can be assigned to the operating points are expediently calculated before the start of the travel of the rail vehicle.

6 The calculation can be carried out, for example, using an electronic computing unit. The efficiency levels for points on the route are expediently determined using a simulation method. The simulation requires, as already described above, the input data which are necessary for the determination of the operating point, that is to say the route profile, permitted maximum speed, temperature, number of wagons, laden weight and the like. The travel of the rail vehicle is subsequently simulated, for example, for operation with one drive unit, wherein the simulation makes available on the output side the resulting efficiency levels as a function of the route profile. The simulation is subsequently repeated, for example, with two drive units. The efficiency levels are therefore known as a function of location. The drive units are expediently in each case a component locomotive, wherein, for example, two component locomotives are embodied as double locomotives and each at the same time constitute a drive unit. In contrast to this, the drive units are electric drive modules of a bogie. Such drive units also comprise, in addition to the actual traction motor, the power inverter, the transmission and the like. Such drive units are, however, known to a person skilled in the art such that more details do not need to be given on this at this point. According to one development of the rail vehicle, means are provided for determining the efficiency levels of the drive as a function of the number of switched-on drive units, wherein the control unit is configured to switch on so many drive units that a maximum efficiency level of the drive is made available.

7 Further advantages are described below on the basis of an exemplary embodiment of the method according to the invention and of the rail vehicle according to the invention with reference to the figures, wherein identical reference symbols refer to identically acting components, and wherein figure 1 shows a route profile of a route with the respectively permitted maximum speed, and figure 2 shows the required tractive force which is calculated for the route profile according to figure 1, and the maximum traction energy of a component locomotive of a double locomotive. Figure 1 shows a route profile in the form of an altitude line as well as a curve showing the respectively permitted maximum speed, which is assigned to the route profile. The distance from the station of origin is plotted on the abscissa. Two ordinates can be seen. The first ordinate has the speed as a unit of measure.

PCT/EP2010/051879 - 8 2009P09576WORU The difference in altitude from the station of origin is plotted in meters on the second rear ordinate. It is apparent that the route of the rail vehicle at the station of origin starts at the altitude of zero meters. The first kilometers of the route are in the urban area. For this reason, a maximum speed of only 40 km/h is permitted. As shown by the lower curve, the route over the first 3 km rises to 6 m. The permissible maximum speed is 80 km/h here. After 43 km, the route rises markedly above 10 km. Figure 2 also shows a curve diagram, wherein the section is illustrated again in meter units on the abscissa. The electrical power is plotted on the ordinate. The jagged curve shows the required tractive force which is calculated for the section profile according to figure 1. In this context, a double locomotive is assumed which has two identical component locomotives. The straight line which runs parallel to the abscissa at 400 kN clarifies the maximum traction power of a component locomotive. It is clear that the jagged line rises above the straight line of the maximum traction power in the region of large gradients on the route. In these areas, both component locomotives of the double locomotive are switched on within the scope of the invention, with the result that the required tractive force can be generated. In other sections, the sole operation of an individual component locomotive is sufficient to meet the requirements made in terms of traction power of the drive. However, in these areas it can nevertheless be more favorable to switch on both component locomotives in terms of the energy consumption or in terms of the feedback capability of braking energy. This is the case when the two component locomotives together require less energy than one component locomotive alone or if in areas with a large negative gradient both component PCT/EP2010/051879 - 9 2009P09576WORU locomotives can feed back more energy into the supply system than just one component locomotive. The driving operation occurs within the scope of the exemplary embodiment of the method according to the invention with two component locomotives if the required tractive force at the point on the route makes it necessary to do so, in other words if the maximum traction power of a component locomotive is less than the required tractive power. The operation occurs with two component locomotives even when a relatively high feedback level of braking energy can thereby be achieved in the braking mode. Moreover, two component locomotives are used even if the overall efficiency level of the two component locomotives is above the efficiency level of one component locomotive at the point on the route. If none of the abovementioned conditions applies, the rail vehicle is operated with one component locomotive. The number of switched-on component locomotives therefore changes as a function of the route profile. At first, points on the route are defined. These can be salient points which indicate the start of a positive gradient or of a large negative gradient. However, the points on the route can also be distributed equidistantly over the route. The operating points of the rail vehicle are firstly determined for the points on the route. As has already been explained above, the operating point can also be referred to as a state of the rail vehicle during travel. The operating point comprises characteristic variables such as speed, gradient of the route at the point on the route, warming of the drive components, rotational speeds and the like. An efficiency level, that is to say the ratio of the mechanical traction energy generated to the electrical energy used, is then calculated for each of these operating points. The calculation is carried out with the efficiency levels of the components PCT/EP2010/051879 - 10 2009P09576WORU of the respective drive unit, such as the main transformer, power converter, traction motor, transmission and the like, which are stored in table form or described with formulas. In this way, an efficiency level of the drive with one component locomotive and an efficiency level of the drive with two component locomotives is determined for each point on the route. According to one of the selection methods illustrated above, the number of drive units or component locomotives is determined in such a way that the highest possible efficiency level during braking or during the traction mode is generated, in which case it is ensured that a sufficiently high level of traction energy is made available. Only a relatively low level of expenditure is necessary to implement the method according to the invention in a rail vehicle. It is therefore possible, for example, to adapt the control software of the drive of the locomotive accordingly. The switching over is carried out, for example, automatically when route information is obtained at specific points on the route, by means of beacons or the like. However, the fact that a point on the route has been reached can also be signaled by the control software of the drive by using satellite-supported locating systems such as GPS or the like. Switching over on the basis of entries in the driver's logbook is also possible within the scope of the invention. First results of the implementation of the invention have shown that the overall energy consumption can be lowered by 3 to 5%. Furthermore, failures of the components of the drive are reduced since the components are less heavily loaded.

Claims

1. A method for controlling the drive of a rail vehicle which has a drive comprising a plurality of drive units, in which the drive units are connected to the drive or disconnected therefrom such that the sum of the traction forces of the switched-on drive units is greater than the required tractive force, wherein the required tractive force is calculated as a function of the route for sections of the route, and the number of switched-on drive units during travel is changed and adapted to the respectively required tractive force, wherein at the specific points on the route the respective operating point of the rail vehicle is determined, an efficiency level is calculated for the determined operating point for each number of drive units which can be switched on, the efficiency levels which can be determined in this way are compared with one another by acquiring an optimum efficiency level, and subsequently so many drive units are switched on that their number corresponds to the number of drive units which are assigned to the optimum efficiency level; and wherein the efficiency levels are determined both with respect to the feedback capability in a braking mode and with respect to the traction force which can be generated.

2. The method as claimed in claim 1, wherein the number of switched-on drive units is changed at points on the route.

3. The method as claimed in claim 2, wherein the required tractive force is calculated for each point on the route, and subsequently at least so many drive units are switched on that the sum of the tractive forces of the switched-on drive units is greater than the required tractive force.

4. The method as claimed in claim 1, wherein the respective operating points and the efficiency levels which can be assigned 12 to the operating points are calculated before the start of the travel of the rail vehicle.

5. The method as claimed in any one of the preceding claims, wherein the efficiency levels for points on the route are determined using a simulation method.

6. The method as claimed in any one of the preceding claims, wherein the drive units are each a locomotive.

7. The method as claimed in any one of claims 1 to 5, wherein the drive units are electric drive modules of a bogie.

8. The method as claimed in claim 6, wherein two locomotives are embodied as double locomotives, wherein each locomotive is a drive unit.

9. The method as claimed in any one of the preceding claims, wherein the required tractive force is calculated with spatial resolution before the start of travel by acquiring a data record.

10. The method as claimed in claim 9, wherein the data record is calculated at a location outside the rail vehicle, and is transmitted therefrom to the rail vehicle by means of data communication.

11. A rail vehicle having a drive comprising at least two drive units, and a control unit which is connected to the drive and is configured to switch the drive units on and off, wherein the control unit has means for making available the required tractive force for specific sections of the route, wherein the control unit changes the number of drive units during travel and switches off the drive units as long as the sum of the tractive 13 force of the switched-on drive units is greater than the required tractive force of the respective section.

12. The rail vehicle as claimed in claim 11, further comprising means for determining the efficiency levels of the drive as a function of the number of switched-on drive units, wherein the control unit is configured to switch on so many drive units that a maximum efficiency level of the drive is made available, wherein the efficiency level is determined both with respect to a feedback capability of the drive units in the braking mode and with respect to the traction force which can be generated.

13. A method, substantially as hereinbefore described with reference to the accompanying drawings.

14. A rail vehicle, substantially as hereinbefore described with reference to the accompanying drawings. Siemens Aktiengesellschaft Patent Attorneys for the Applicant/Nominated Person SPRUSON & FERGUSON