DE102009045448A1 - Vehicle, particularly service bus, for driving operation in stages between respective battery replacement bases with intermediate stops, has electric motor that is provided as main drive motor - Google Patents

Abstract

The vehicle, particularly service bus, has an electric motor that is provided as main drive motor and a power supply device for the electric motor, which has a removable battery (6) that is provided as base energy source of the electric motor. An activated reserve power supply unit is provided for supplying electricity. An independent claim is also included for a method for driving operation of a vehicle.

Description

The The invention relates to a vehicle which is in a driving operation in Stages, such as a bus service, are used can. The vehicle is powered by an electric motor, the powered by a rechargeable battery.

Buses make a significant contribution to urban transport. Buses are usually still operated with fossil fuels, such as diesel fuel. Despite the already low consumption per passenger, the vehicles, which are usually operated in passenger transport on repeatedly repeatedly traveled routes, offer a considerable savings potential for both energy consumption and CO ² emission.

It already different drive variants for such Used vehicles that reduce the consumption of fossil fuels or completely abstain from fossil fuels. So is It is known, with regenerative internal combustion engines electric Energy for an electric drive of a vehicle provide. In addition, high-performance batteries can be used here or high-performance capacitors (so-called ultra-caps) energy for short-term high power requirements, such as during acceleration or when traveling uphill.

A Further efficiency increase can be achieved through the recovery of braking energy and their storage in the battery and / or reach the capacitors. This is the electric motor of the vehicle regenerative and thus operated as a "brake".

Still more energy-efficient hybrid powertrains use a fuel cell that generates chemical electrical energy instead of the internal combustion engine. The state of the art in this regard z. B. on the EP 1868837 B1 directed. A fuel cell is used in the known drive as the main energy source for the electric motor. To provide short-term peak performance, both a "minute memory" battery and a plurality of high-power capacitors connected in series are provided as "seconds of memory". Braking energy can be stored back into the battery and capacitors by the generator-driven electric motor.

all The energy supply systems described above have in common that the main source of energy is still fossil fuel or other continuous fed, chemically converted into electrical energy Are energy sources. To almost completely to be able to dispense with such energy sources Already used vehicles with a battery as their main source of energy operate. The scientific development in recent years has the performance data of batteries, such as energy content, minimal charging time or the removable power so increased and The costs are lowered so that batteries as the sole power supply for vehicles, in particular buses, practicable and economical became interesting. So buses have already been used in which installed a sufficiently large sized battery was to the driving of the bus throughout the day sure. To provide the energy for this operation, the battery must have a very high energy content, which at considerable battery costs and at a very large Weight of the battery leads.

One Another limiting factor in this system is recharging the battery. For recharging the battery one Vehicle of the above type, will be different ways offered. For a permanently installed battery in the vehicle, the Battery within a usually short service life the bus are completely recharged. Such a Fast charging will adversely affect battery life out.

It were also inductive charging solutions, for example, intermediate stops proposed by the bus. But this must be done in a very short time very large amount of energy can be charged into the battery, which again brings the above-mentioned disadvantages.

It has also been proposed, buses with a removable battery to operate, such that at the end of driving one day the almost discharged battery against a fully charged in the depot Battery is to be replaced. This allows the battery to be essential load more slowly and thus increase their service life. However, this option has a disadvantageous effect the big volume and the very high weight of the battery and the rugged battery mounts on the bus. Such heavy batteries can not be supported on the roof of the bus because they overwhelm the roof's stability and would shift the focus significantly upwards; instead, such batteries are usually in a hard to reach Floor area of the bus installed.

Object of the present invention is to provide a vehicle with a low-cost power supply, which largely dispensed with physically or chemically reacting and continuously supplied fuels and whose energy management requires only little effort changed.

The Task is solved by a vehicle for one Driving in stages between respective battery replacement points with any intermediate stops, with an electric motor as the main drive motor and with a power supply device for the electric motor, the at least one rechargeable replaceable battery as the base energy source of the electric motor whose energy content is fully charged Condition is calculated so that they are the expected energy needs of the vehicle for the current stage to the next Battery replacement point with a safety margin of z. B. 150% -500% and can be activated as needed Reserve power supply unit for providing electrical energy in the case of a rechargeable energy content Replacement battery energy requirements of the electric motor for a trip to the next battery replacement point having.

Preferably In addition, the energy supply device comprises at least an electric capacitor for the provision of Energy for temporary high-load operation of the electric motor.

One in a regular service operated bus runs normally a predetermined stage before returning to its final stop. This stage is then repeated throughout the day. Most are the stages comparatively short and are for example in one Drive through time of about an hour. As in the invention a Battery is installed in the vehicle whose energy content with a certain safety margin of preferably 150% -500%, especially 150% -250%, sufficient to get the vehicle up energizing the stage can be much smaller and thus installed lighter and cheaper battery when they are driving over the needed all day. To put the battery on one Ride does not fully unload and also a certain Reserve with lead, is preferably the energy content of the battery in the manner mentioned above, that it is about 1.5 to 5 times, especially 1.5 to 2.5 times the expected energy consumption of the vehicle on the respective current stage corresponds.

Around a deep discharge of the battery or even a lingering of the Prevent vehicles from unexpectedly increased energy demand, as he for example by detour routes on the usual Driving distance of the vehicle or by persistent stop-and-go traffic can be caused is a demand-activated reserve power supply unit provided, which is usually not at all Use comes. This reserve power supply unit feeds over a generator loads and charges electrical energy into the system so the battery. Preferably, the reserve power supply unit an internal combustion engine that operates a generator.

Prefers if the maximum power of the internal combustion engine is less than 60 kW, especially small than 30 kW.

The Reserve power supply unit is merely an emergency unit represent that a ride to the next battery replacement point ensures. The reserve power supply unit should therefore be so small be dimensioned so that they use as little as possible, has little space and low weight. So it will be for undersized the main operation of the vehicle and therefore not be able to use the vehicle in the usual way to operate.

To the Providing energy for a temporary High load operation, such as when accelerating at least one, preferably a plurality of series electrical Capacitors are available. Due to the purely electrostatic Energy storage in the capacitors can do this without Damage can be loaded and unloaded quickly and points while a relatively low power loss at the same time almost immediate service provision.

Especially it is preferred that the energy supply device comprises a control device, which is set to fall below a predetermined Partial discharge state of the rechargeable replaceable battery, the reserve power supply unit automatically switch on.

Preferably corresponds to this Teilentladezustand 30% to 60% of the full state of charge. Furthermore, the vehicle is preferably configured to be electric converted braking energy into the battery or / and the capacitor to be stored, preferably by the operation of the electric motor as Generator. The recovery of braking energy continues to increase the energy efficiency of the drive. Just by the regular Stop at intermediate stops in a scheduled service drops significantly braking energy.

Simulations of the inventor have shown that the energy content of the battery is preferably to be dimensioned so that for each kilometer of a distance an energy between 1.0 and 1.6 kWh, in particular 1.3 kWh allows optimal driving operation of an average bus. This value may vary depending on the vehicle weight and possibly also on the vehicle differ from the specified interval.

Preferably the vehicle is a bus.

Especially preferred is a lithium-ion battery as primary Energy source.

The inventive object is further solved by a method for driving a vehicle according to one of the preceding claims on a driving route with one or more stages, with each stage through a first battery replacement point as the starting point and a second battery exchange point as an end point is limited, with the driving on a particular stage The following steps include: Traveling a Stage from the first battery change support point to the second battery change support point; Approaching any intermediate stops on the stage; repeated Checking the charge status of the rechargeable replaceable battery and automatic connection of the reserve power supply unit, if the state of charge is a predetermined partial discharge state level has fallen below; Replace the battery at the second battery replacement point against a substantially fully charged battery.

The Vehicle begins its journey on a leg at a first battery replacement point a substantially fully charged battery. On the stage will be approached any intermediate stops. At the Reaching the second battery replacement point at the end the stage, the battery is significantly discharged so that it returns should be charged. At this second battery replacement point Then, this discharged battery is against a substantially fully charged battery replaced. At the stage finds a steady check of the state of charge of the rechargeable Replacement battery instead. Becomes a predetermined partial discharge state achieved, which should not happen under normal circumstances, since the battery is sufficiently large, is the reserve power supply unit automatically switched on.

Around to design the most efficient driving possible replacing the battery at a respective battery replacement point preferably automatically. This can be done for example by a provided for this battery replacement device, in which the bus goes in, done. At such a battery exchange base can then, for example, a warehouse with charging stations for be replaced batteries provided. Preferably, this will Bearings automatically operated and fully charged batteries, which are to be replaced with discharged batteries, too automatically selected. It is particularly preferred if the first and the second battery exchange support the same Battery replacement base are. This can be the case be when the vehicle is operated in a line operation, wherein it starting from a final stop a loop-shaped Line travels and then returns to its final stop.

It But it is also possible that the bus is on its route moves to several different battery replacement points, where rechargeable replaceable batteries as described above be replaced. The process steps on a single Stage between two battery replacement points are the same as described above. The energy management is thus in a stage driving operation adapted, being small, light weighted and inexpensive Standard batteries can be used in which it the time required to reload is not particularly important. It does not therefore have expensive batteries with fast charging characteristics be used.

embodiments The invention will be described below with reference to the figures described.

1 shows an electric motor driven articulated bus with a battery on its roof as a power supply;

2 shows an electrical circuit with a battery for powering the electric motor of the articulated bus of 1 ;

3 shows method steps for the operation of a bus that runs on a closed stage, in each case at the final stop the battery is changed;

4 shows the method steps for operating a battery-powered vehicle on a route with multiple stages.

In the 1 is a articulated bus 2 shown how it is often used in a regular service. The articulated bus 2 is driven by an electric motor, not shown. This electric motor is primarily powered by a roof 4 of the articulated bus 2 mounted rechargeable replaceable battery 6 energized. The battery 6 is through a fastening device 8th mounted on the roof so that it can be easily replaced. The battery 6 In particular, it is mounted by an automatic battery changing device from the roof 4 of the bus 2 can be removed and can be replaced in a similar manner by a battery of the same design.

The battery is still protected 10 provided to protect them from environmental impact. For the protection 10 also applies that this is constructed so that a simple and fast access during automatic battery replacement can be done by an automatic battery replacement device.

by virtue of The favorable performance data is the battery preferably a lithium-ion battery.

The battery 6 is the primary source of power for the electric drive of the bus 2 , The energy content of the battery is dimensioned so that it is sufficient, the bus 2 in its normal running regular service on its route from the final stop along the entire line back to the final stop to provide energy. It can, for. For example, a safety margin of 150% -250% may be calculated so that under normal conditions the bus could cover 1.5 to 2.5 times the distance traveled with the battery as an energy source. A certain amount of battery reserve is expediently to be considered for vehicle air conditioning.

In the 2 shown circuit arrangement 12 enabled on the basis of a battery 6 as a basic energy supply source, moreover, a satisfactory power supply of the bus 2 in almost all driving situations. The electric motor 14 of the bus 2 is about a converter 16 driven. The converter 16 converts those in a circuit 18 provided DC voltage in AC voltage for the operation of the electric motor 14 around. The drive motor 14 can z. B. be a permanent magnet synchronous machine. The prime mover 14 can also be operated as a generator, so that the power generated during generator operation, for example, during a braking operation in the converter 16 is converted into DC voltage and into the circuit 18 is fed. Of course, it is also possible to use a plurality of drive machines, which are placed on a respective wheel of the vehicle and are correspondingly integrated in the circuit.

To power the prime mover 14 stand next to the battery 6 two more power systems available. In order to be able to provide high performance in the short term, the second energy supply unit is 20 a plurality of memories for storing electrical charge, in particular double-layer capacitors connected in series 22 (Ultra-Caps) to the battery 6 connected in parallel. The capacitors, in particular Ultra Caps, have a very high energy density and store energy electrostatically. Unlike a chemical energy storage such as a battery, a capacitor can absorb or deliver high power quickly.

The series connected capacitors 22 serve when operating the bus 2 to provide high power for a short time during acceleration or when driving uphill, in particular a power that would exceed the capacity of the battery. In normal driving are the capacitors 22 charged to the battery voltage.

The energy content of the battery 6 is sized to the bus 2 on its usual route from its final stop along its line back to the final stop can provide energy. In the event of unforeseen route extensions, such as construction site diversions, or energy-intensive excessive stop-and-go traffic, the battery will become 6 discharged further than usual due to the increased energy consumption. In order to avoid damage to the battery and continue to maintain sufficient power for driving, therefore, an internal combustion engine (not shown) is provided, which drives a generator, such as a conventional alternator. The generator is at connection points 24 . 26 in the circuit 18 integrated and also to the battery 6 connected in parallel. In situations where the battery 6 further than allowed to discharge, the regenerative internal combustion engine feeds via the connections 24 . 26 Energy in the circuit 18 and charges the battery 6 ,

As already described above, the prime mover can 14 be operated as a generator, so that when braking the vehicle, the deceleration power is generated by the generator and this current through the converter 16 in the circuit 18 feeds. The generated energy is in the battery 6 or the capacitors 22 cached until its maximum charge capacity is reached. When fully stored, the braking power in a brake disc 28 be destroyed. The brake disc 28 consists of a braking resistor 30 and a circuit breaker 61 ,

The high power generated during a braking process provides for the capacitors 22 No problem, but the charging power of the battery 6 be managed. This is done via a battery charging control circuit 34 , The battery charging control circuit consists of a diode 36 and a DCDC converter connected in parallel thereto 38 , The flow of energy from the battery to the electric motor flows either through the DCDC converter 38 or, if the capacitors 22 are sufficiently discharged, over the diode 36 , In the case of energy flow from the generator-driven prime mover 14 locks the diode 36 and the charging power is provided by the DCDC converter 38 regulated.

With the power supply circuit described above 12 can thus the driving of the bus 2 be ensured in all driving situations. In normal-load operation, the battery powers 6 the prime mover with energy. For short-term high power, such as acceleration or hill climbing, support the capacitors 22 the energy supply. Should the battery be discharged unauthorized by unforeseen circumstances, the generator of the internal combustion engine provides energy for charging the battery.

In the driving mode of a bus operated in the regular service 2 The energy content of the battery is chosen so that the energy is sufficient to the bus 2 on his constantly repeated stage from his final stop to the return stop and back to the final stop to provide energy. At the final stop then the battery 2 that z. B. is discharged to 40% to 50% of its full charge capacity, replaced with a built-in charged battery. The discharged battery is then recharged at the final stop. In this case, the charging time of the battery to its fully charged state can correspond approximately to the time required for the bus to pass through the entire stage. As in 3 Thus, when the bus starts at the starting point of the stage, it stops at the intermediate stage and finally arrives at the end point of the stage. The end point of the stage is just the starting point of the next stage in a looped bus. At the end point of the stage or starting point of the stage then takes place the battery change. The battery is replaced by an automatic battery replacement system. After changing the battery, the bus passes through 2 again the stage and returns to the starting point. Again, the discharged battery is replaced with the battery fully charged during this time. The now discharged battery is charged at the battery replacement point. By this operating method, it is possible to operate the bus continuously with a few, small-sized batteries that are constantly changed.

The bus does not necessarily have to drive in a loop-shaped stage, where it always returns to the starting point of the stage and the battery is always changed at the same battery replacement point. For longer distances several battery replacement points are provided on the entire route. As in 4 shown, the bus passes through the first stage. At the end of the first stage, the battery is changed to a fully charged battery. The discharged battery is charged at this battery replacement point. The bus can now pass through a second stage to a next battery changeover point, where a battery change takes place again. However, there is also the possibility that the bus will return to the starting point of the first leg from the end of the first leg after the battery change. Here again the battery is changed. If the bus has passed through a second stage, it is possible to return from this battery replacement point to the starting point of the second stage. However, the bus can also continue to another battery exchange base, for example, the starting point of the first stage.

As in 4 indicated, of course, the number of stages or battery replacement support points can be arbitrarily increased. It is only ever to ensure that the energy content of the battery used at a respective battery replacement point is selected so that the energy content is sufficient to pass through the next stage.

As From the foregoing description, the method is to operate a vehicle with one or more removable batteries extremely flexible. Therefore, it is not just about the operation of a bus limited, which always leaves the same line, but it is also possible for example a taxi or a city-operated delivery vehicle with such a system to supply. Especially in inner city operation are too here the stages or journeys to be covered are comparable long. Battery change points in the form of taxi stands are also available.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 1868837 B1 [0005]

Claims (14)

Vehicle, in particular regular-service bus, for driving in stages between respective battery replacement support points with any intermediate stops, with - an electric motor ( 14 ) as a main drive motor and - with a power supply device for the electric motor, the at least one rechargeable replaceable battery ( 6 ) as the base energy source of the electric motor ( 14 ), whose energy content in the fully charged state is such that it can cover the anticipated energy requirements of the vehicle for the respective current stage to the next battery exchange support point preferably with a safety margin of 150% to 500%, and a need to activate reserve power supply unit for providing electrical energy in the case of the energy content of the rechargeable replaceable battery ( 6 ) exceeding the energy requirement of the electric motor ( 14 ) for a trip to the next battery exchange support point. Vehicle according to claim 1, characterized in that that the reserve power supply unit is an internal combustion engine is who operates a generator. Vehicle according to claim 2, characterized in that that the maximum power of the internal combustion engine is less than 60 kW, especially less than 30 kW. Vehicle according to one of the preceding claims, characterized in that the energy supply device further comprises at least one electrical capacitor ( 22 ) for the provision of energy for temporary high-load operation of the electric motor ( 14 ). Vehicle according to one of the preceding claims, characterized in that the energy supply device comprises a control device, which is adapted, in a partial discharge state of the rechargeable removable battery ( 6 ) automatically switch on the reserve power supply unit. Vehicle according to claim 5, characterized in that that the partial discharge state 40% -50% of full charge is. Vehicle according to one of the preceding claims, characterized in that it is adapted to transfer braking energy into the battery ( 6 ) and / or the capacitor ( 22 ), preferably by the operation of the electric motor ( 14 ) as a generator. Vehicle according to one of the preceding claims, characterized in that the battery ( 6 ) has an energy content that is dimensioned so that for each kilometer of a distance an energy between 1.0 and 1.6 kWh, in particular 1.3 kWh, can be provided. Vehicle according to one of the preceding claims, characterized in that it is a bus. Vehicle according to one of the preceding claims, characterized in that the battery ( 6 ) is a Li-ion battery. Method for driving a vehicle according to one of the preceding claims, on a driving route with one or more stages, with each stage through a first battery replacement point as the starting point and a second battery exchange point as an end point is limited, with the driving on a particular stage the steps includes: Returning a leg of the first battery change support point to the second battery change support point; hit any intermediate stops at the stage; repeated Checking the charge status of the rechargeable replaceable battery and automatic connection of the reserve power supply unit falls below a predetermined Teilentladezustandes; Change the battery at the second battery replacement point against a substantially fully charged battery. A method according to claim 11, characterized by automatic replacement of the battery at a respective battery replacement point. A method according to claim 11 or 12, characterized by charging the replaced partially discharged battery to the respective one Battery replacement base. Method according to one of claims 11 to 13, characterized in that the first and the second battery exchange support point are the same battery replacement point.

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