DE102009055845A1 - Charging station for electrically powered vehicles - Google Patents

Abstract

The invention relates to a charging station for supplying electrical energy to electric vehicles (2), comprising a removal point (3) for the electrical energy. The object of specifying a charging station for supplying electrically operated vehicles with electrical energy, the charging station being able to emit high energy with low losses in a short time in a number of cycles, in particular without putting too much strain on the public power grid, is achieved according to the invention by a Flywheel storage (5) arranged at the extraction point (3) as a temporary store for the electrical energy. The invention further relates to a method for operating a charging station for supplying electrically operated vehicles (2).

Description

Field of the invention

The invention relates to a charging station according to claim 1 for electrically operated vehicles, ie vehicles with an electric drive or with an electric auxiliary drive and a memory for electrical energy, and a method according to claim 4 for operating a charging station.

Vehicles are known from the prior art, which have an electric drive, or at least one if necessary switchable electric auxiliary drive. Such vehicles require the inclusion of electrical energy at charging stations at regular intervals. The electrical energy provided at the charging stations can for example be taken from the public power grid or generated on the spot, for example, by providing a solar system at the charging station whose generated electrical energy can be delivered to the vehicles. It is also known to store the energy in a buffer for electrical energy, such as an electric battery, so that in the case of charging the vehicle, the cached in the battery electrical energy can be retrieved at short notice.

For the delivery of electrical energy of, for example, about 10 kWh in a short time, for example about 5 minutes, existing charging stations are hardly suitable because the batteries in question have longer charging and discharging times. Also, an energy withdrawal in the specified magnitude within a few minutes, a high load on the public grid, so that in unfavorable cases, the power grid can collapse.

The requirement of a high energy output (about 10 kWh) in a short period of time (about 5 minutes) with a high repetition rate can only be met inadequately.

DE 10 2006 047 654 A1 describes a charging station for electrically powered vehicles, wherein the respective vehicle has an energy storage. The charging of the vehicle is done by simply replacing the empty energy storage against a filled energy storage. For this purpose, a mechanical gripper device is provided. Unfavorable is that replenished energy storage must be kept in larger numbers in stock, as well as continue to accumulate empty energy storage, creating a lot of space.

DE 295 05 733 U1 describes a charging station for an electrically powered vehicle, wherein within a maximum of four hours a maximum power of 5 kW is delivered. This charges an existing battery within the vehicle.

DE 92 12 818 U1 proposes to provide on the vehicle an energy storage or an energy buffer, for example in the form of a trailer. However, this increases the mass and thus the energy requirements of the vehicle.

DE 10 2006 006 692 A1 describes a charging station with an inductive delivery of electrical energy to a vehicle. In the vehicle, an energy storage, such as a flywheel, is arranged, which caches the electrical energy emitted by the charging station, so that the vehicle receives a greater range. Another disadvantage is that the energy storage, in particular the flywheel mounted on the vehicle, increases the mass and thus the energy consumption of the vehicle.

Object of the invention

It is the object of the invention to provide a charging station for the supply of electrically operated vehicles with electrical energy, the charging station can deliver a high energy with low losses in several cycles in a short time, in particular, without burdening the public power grid too much.

Summary of the invention

This object is achieved for said charging station according to the invention according to claim 1 by a arranged at the removal point flywheel storage as a buffer for the electrical energy. Since per se known flywheel storage are generally suitable as a buffer for the removal point of the charging station, this object is achieved in particular by the use of a flywheel storage as a buffer for electrical energy at the charging station for the supply of electrically powered vehicles with electrical energy. The solution of the object according to the invention allows a method according to claim 4 for operating a charging station.

Flywheel accumulators provide the ability to convert electrical energy into mechanical energy in a short time by rotating a flywheel in the flywheel accumulator, as well as keeping the energy largely stored without losses, by keeping the rotating flywheel in rotation, for example a contacting one Storage of the flywheel in a sliding or rolling bearings, or in a non-contact mounting of the flywheel in an active or passive magnetic bearing. The flywheel storage further provides the ability to convert the electrical energy stored in a mechanical manner by braking the rotating flywheel in a short period of time into electrical energy and, for example, to supply the vehicle. Due to the low response times flywheel storage are suitable to intercept an overload of the public power grid and continue to perform an energy delivery to the electrically powered vehicle in a short period of about a few minutes.

The charging station thus offers the possibility of carrying out the charging of the vehicle in a period of time which corresponds substantially to the usual time span for filling the vehicle with liquid fuels such as gasoline.

The flywheel storage takes up little space, which essentially corresponds to the space requirement of a known fuel pump for liquid fuel and is preferably arranged sunk in the ground below the sampling point.

The flywheel accumulator can be easily retrofitted into existing charging stations by between the sampling point, on which, for example, an electrically conductive connection is made to the vehicle, and the supply of the charging station with electrical energy, such as the connection of the charging station to the public grid, the Flywheel storage is installed. In particular, each individual sampling point is assigned at least one flywheel storage. Further, the receiving station is connected to the at least one sampling point by interposing at least one flywheel storage of the public power grid.

The flywheel storage preferably has a communication unit that can exchange information with external communication units located outside the charging station. The communication unit of the flywheel storage unit can be addressed, for example, by an external communication unit of an electric vehicle whose driver dials the communication unit of the flywheel storage unit like a mobile telephone. Via the communication unit, the driver or, advantageously, the navigation device installed in the vehicle can inform the flywheel storage device of its energy requirement and the estimated time of arrival. As feedback, the communication unit of the flywheel accumulator can notify the driver or his navigation device of the availability of the energy and / or the expected waiting time.

The communication unit of the energy storage device gives the driver a better supply security, since the charging possibility is confirmed before or during the journey to the charging station. The flywheel storage can save considerable stand-by losses due to the communication unit, since in times without advance notification, the rotational speed of the flywheel and thus friction losses can be reduced. It is also possible to use the communication not only with customers but also with the operator of the supply network in order to buffer short-term fluctuations in the network for the grid operator in times when there are few charging stations (which are given priority).

A reduction in idle speed in stand-by times can significantly reduce the annual self-consumption of the flywheel accumulator and thus increase cost-efficiency, given the low capacity utilization of many charging stations. The usage option for the network operator to use the power storage to improve the network quality if necessary can also increase the economy of the charging station by reducing the energy consumption.

Further advantages and features of the invention will become apparent from the claims and from the description of a preferred embodiment.

The invention will be described and explained in more detail below with reference to the accompanying drawings.

Brief description of the drawings

1 shows schematically an embodiment of a charging station according to the invention, and

2 schematically shows a modification of the in 1 illustrated embodiment.

Detailed description of the drawings

1 shows a charging station 1 for the supply of electrically operated vehicles, for example, provided with an electric energy storage vehicles 2 , with electrical energy. The charging station 1 includes a sampling point 3 for the electrical energy, the sampling point 3 an electrical line 4 has, at the end of an electrically conductive connection to the motor vehicle 2 can be made to the electrical energy in the motor vehicle 2 save.

The charging station 1 further includes a flywheel storage 5 at the exit point 3 is arranged so that over the electrical line 4 the electrical energy previously in the flywheel storage 5 as kinetic energy was cached to the vehicle 2 be delivered can. Between the exit of the flywheel storage 5 in which the kinetic energy is converted into electrical energy, and the motor vehicle 2 lies a distance that is essentially the length of the electrical line 4 corresponds to a maximum of only a few meters. The flywheel storage 5 is thus in spatial proximity to the sampling point 3 for the vehicle 2 stationary, in particular below the ground and thus invisible, arranged, with electrical conduction losses between the output of the flywheel storage 5 and the vehicle 2 keep low.

The flywheel storage 5 includes a flywheel 6 , So a mass that has a certain moment of inertia relative to a defined axis of rotation. The flywheel 6 is rotatably mounted in a housing, for example by means of a contact bearing (in particular a rolling or a sliding bearing) or by means of a substantially non-contact storage (for example, an active or passive magnetic storage or aerodynamic storage). The flywheel 6 is rotated or held in rotation by the supply of electrical energy in the electric drive of the flywheel storage 5 where the the flywheel storage 5 supplied energy of an energy source, in particular a power supply network, is taken.

The first energy source of the charging station 1 is an alternating voltage network 7 , with which an input of the flywheel storage 5 is connected, being between the alternating voltage network 7 At a connection point of the power supply inverter are provided, which transform the AC voltage. The alternating voltage network 7 For example, it may be a high voltage network or a network that provides a three-phase rotation voltage, with the sum of the amplitudes of the three phases providing a voltage of zero volts at each instant.

The second energy source of the charging station 1 is a direct voltage network 8th with which the input of the flywheel storage 5 is connected, wherein at a connection point with the DC mains 8th a further converter is provided, which makes an AC voltage from the DC voltage. The DC voltage of the DC voltage network 8th can be dispensed, for example, from a battery that is powered by solar power during the day and when needed to the AC mains 7 can be switched on.

In particular, it is provided that the flywheel storage 5 optionally from the direct voltage network 8th and from the AC mains 7 can be fed. It goes without saying that the flywheel storage 5 also exclusively from the direct voltage network 8th or exclusively from the AC mains 7 can be fed.

The invention works such that when charging the vehicle 2 at the sampling point 3 the flywheel storage 5 its mechanical energy as electrical energy to the vehicle 2 gives off, with the energy needs of the vehicle 2 can be transmitted within a few minutes. The then energetically emptied flywheel storage 5 is again charged in the following, for example, by the AC voltage network 7 or the DC mains 8th , The flywheel storage 5 acts as a buffer, the short-term resulting high energy demand when charging the vehicle 2 opposite the power grids 7 . 8th buffered, leaving a short-term overload of power grids 7 . 8th is prevented.

In the embodiment described above, the only extraction point was 3 a single flywheel storage 5 assigned. It is understood that a sampling point can be assigned several flywheel storage, of which when charging the vehicle 2 only one is unloaded at a time.

Includes the charging station 1 more than just a sampling point 3 , multiple tapping points can access a common flywheel storage.

It is understood that these options can be combined by the charging station 1 by means of a first flywheel storage against the voltage networks 7 . 8th is buffered, while the multiple tapping points of the charging station in turn have at least one flywheel storage. The flywheel storage of the respective extraction point then does not draw its electrical energy directly from the voltage networks 7 . 8th but from the common flywheel storage of the charging station 1 ,

In 2 is schematically a flywheel storage 5 shown in its control electronics 9 a communication unit 10 integrated, which via radio with other, external communication units 11 Can exchange information. These other external communication units 11 are those of vehicles 2 whose driver can communicate or query information via SMS, or navigation devices of vehicles 2 that exchange information packets according to specific protocols. The information includes, for example, an indication of the anticipated need for electrical energy and an indication of the time at which the electrical energy to the vehicle 2 to be transferred. The communication unit 10 the flywheel storage 5 is in the control electronics 9 the flywheel storage 5 integrated and has transmitting and receiving units 12 for radio signals. Another communication partner is schematically a process control computer 13 a local grid operator of the power grid, its electrical energy in the flywheel storage 5 cached is shown. The process control computer 13 captures the energy requirements of all vehicles 2 and controls the supply of electrical energy into the network so that the network is optimally utilized, in particular so that no overload occurs in the network and the energy needs of all consumers of the network, including all powered by the network flywheel storage 5 , can be met.

If no specific need for electrical energy is determined, the control electronics 9 the flywheel 6 the flywheel storage 5 operated in a "rest state" (stand-by mode) with a reduced speed (for example, from 30,000 to 6,000 rpm) and thereby reduced speed-dependent friction losses in the example by about 80%. Once a customer has the external communication unit 11 and the flywheel storage 5 assigned communication unit 10 announces a demand for electrical energy, the speed of the flywheel is adjusted to the expected demand time and the amount of electrical energy required 6 elevated. By the need-driven driving the speed of the flywheel 6 the flywheel storage 5 can the charging station 1 operate so that the losses due to the friction of the flywheel 6 be significantly reduced in storage. The annual losses of the flywheel energy storage unit can be reduced by about 72% with an effective service life of 10% (876 h / a), for example.

In the embodiment described above, the exchange of electrical energy between the flywheel storage was 5 and the vehicle 2 through an electrical line 4 intended. It is understood that also a non-contact exchange of electrical energy between the flywheel storage 5 and the vehicle 2 may be provided, for example by means of an inductive energy transfer.

LIST OF REFERENCE NUMBERS

1

charging station

2

vehicle

3

sampling point

4

electrical line

5

flywheel energy storage

6

flywheel

7

AC network

8th

DC power

9

Control electronics

10

Communication unit of the flywheel storage 5

11

external communication unit to vehicle 2

12

Transmitting and receiving unit of the communication unit 10

13

process control

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited patent literature

• DE 102006047654 A1 [0005]
• DE 29505733 U1 [0006]
• DE 9212818 U1 [0007]
• DE 102006006692 A1 [0008]

Claims (5)

Charging station for the supply of electrically operated vehicles ( 2 ) with electrical energy, comprising a withdrawal point ( 3 ) for the electrical energy, characterized by a at the sampling point ( 3 ) arranged flywheel storage ( 5 ) as a buffer for the electrical energy. Charging station according to claim 1, characterized in that the flywheel storage ( 5 ) a communication unit ( 10 ) connected to external communication units ( 11 ), which are outside the charging station, exchanges information. Charging station according to claim 2, characterized in that the communication unit ( 10 ) in a control electronics ( 9 ) of the flywheel storage ( 5 ) and transmitting and receiving units ( 12 ) for radio signals. Method for operating a charging station according to one of Claims 1 to 3, characterized in that a rotational speed of the flywheel ( 6 ) is driven as needed. Use of a flywheel accumulator ( 5 ) as a buffer for electrical energy at a charging station ( 1 ) for the supply of electrically operated vehicles ( 2 ) with electrical energy.

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