DE102016006801A1 - Charging device for inductively charging an energy storage device and method for operating such a charging device - Google Patents

Abstract

The invention relates to a charging device (12) for inductively charging an energy accumulator of a motor vehicle (10) with electrical energy, with at least one first energy transfer component (14), via which energy to at least a second energy transfer component (16) of the motor vehicle (10) is inductively transferable and at least one electrical heating element for at least partially heating the first energy transfer component (14), wherein electrical heating element is adapted to detect precipitation on the first energy transfer component (14) and objects (20) disposed between the energy transfer components (14, 16).

Description

The invention relates to a charging device for inductively charging an energy storage device of a vehicle, in particular a motor vehicle, according to the preamble of patent claim 1 and a method for operating such a charging device.

Such charging devices are already well known from the prior art. In particular, such charging devices are known from mass-produced motor vehicle construction. The DE 10 2011 076 186 A1 For example, discloses an arrangement and method for remedying a failure of a wireless power transmission. Here, for example, water, dirt, snow, ice or garbage such as tin cans or chewing gum can be removed in the transmission path of the wireless power transmission or a fire can be deleted. To remedy faults, various mechanical means for automatic cleaning and drying are presented. For example, the components for inductive charging can be sprayed by means of a washing nozzle and then dried with a blower. Alternatively, the components may be tilted, swung or shaken to remove objects, leaves, dirt or moisture. Optionally, sensors are used to determine a degree of contamination or the nature of a fault. The charging process can also be adjusted or suspended until the removal of detected interference factors.

Thus, a charging device for inductive charging of an energy storage of a motor vehicle with electrical energy is known, with at least a first energy transfer component, via which energy to at least a second energy transfer component of the motor vehicle is inductively transferable, and at least one electric heating element for at least partially heating the first energy transfer component.

The DE 10 2012 103 321 A1 discloses an apparatus for condition monitoring a housing of a primary or secondary coil of a device for inductive transmission of electrical energy from a stationary unit to a motor vehicle adjacent thereto. In this case, in or on the housing between that surface side, which faces the other coil in the transfer mode, and the coil located in the housing at least one measuring line is arranged, which has a plurality of loops, which together between said surface side of the housing and the Define coil lying surface whose outer contour in the projection on said surface side of the housing surrounds the outer contour of the coil. The measuring line is connected to an electrical measuring device which detects at least one measured value dependent on the electrical resistance of the measuring line. The measuring device is connected to an evaluation device which derives at least one signal from the measured value detected by the measuring device, which indicates a state of said surface side of the housing.

Object of the present invention is to develop a charging device for inductive charging of an energy storage and a method of the type mentioned in such a way that the energy transfer can be particularly simple and thus improved cost.

This object is achieved by a charging device with the features of claim 1 and by a method having the features of claim 5. Advantageous embodiments with expedient developments of the invention are specified in the remaining claims.

In order to develop a charging device specified in the preamble of claim 1 type such that the energy transfer can be particularly simple, especially with a low construction cost, and thus particularly cost-effectively improved, it is inventively provided that the electric heating element is designed to precipitate the first energy transfer component and to detect objects arranged between the energy transfer components. In particular, by means of the heating element objects, in particular metallic objects, which are located in an air gap between the energy transmission components, can be detected, wherein a magnetic field is formed in the air gap during the inductive charging.

The energy storage device which can be inductively charged by means of the charging device is, for example, a traction battery, by means of which at least one electric machine for driving the motor vehicle can be supplied with electrical energy stored in the traction battery. Usually, the electric machine is also referred to as a traction machine. In this case, the motor vehicle can be designed as an electric vehicle or as a hybrid vehicle. For inductive charging of such a traction battery is usually a high energy density in the inductive charging, so that in particular metallic objects which are optionally arranged during charging between the energy transfer components are strongly heated.

In order to destroy or damage the respective energy transfer component, in particular the first energy transfer component, which also serves as a primary coil is designated and may be designed as a bottom coil unit to prevent, the metallic objects should be detected, so then, for example, the energy transfer can be stopped. Furthermore, in particular the bottom coil unit should be kept free from dirt, in particular from precipitation, in order to be able to ensure a particularly effective and efficient energy transmission.

For this purpose, it is provided according to the invention that the electrical heating element is designed to detect precipitation on the first energy transmission component. Furthermore, the heating element is designed to detect objects arranged between the energy transmission components. In this case, the charging device comprises, for example, an electronic computing device, which is also referred to as a control device and is designed to operate, in particular for controlling or controlling, the electric heating element.

For detecting the precipitate or the objects, the electric heating element is operated as a capacitive sensor. If precipitation is present on the first energy transmission component and / or if there is at least one object between the energy transmission components, this leads to a change in capacitance, in particular between the electrical heating element and at least one further component, such as the second energy transmission component. This change in capacitance occurs in particular in comparison to a state in which there is no precipitate on the first energy transmission component or in which no object is arranged between the energy transmission components. Such a capacitance change can be determined or detected, for example, via the electrical heating element by means of the control device, so that it can be detected that precipitation on the first energy transmission component or metallic objects are located in an air gap between the energy transmission components.

If it is detected, for example, that a particularly metallic object is located between the first energy transmission component (primary coil) and the second energy transmission component, which is also referred to as a secondary coil, then the control device can prevent, for example, inductive charging and thus prevent damage. Furthermore, the control device can control the heating element accordingly and remove, for example, snow or precipitation by means of the heating element, if, for example, it is detected that precipitation is located on the primary coil.

The heating element thus has a dual function. On the one hand, the heating element is used as a sensor by means of which a disturbance in the form of precipitation located on the first energy transfer component can be detected. Further, the heating element is used to eliminate the interference by, for example, melting and / or evaporating the precipitate.

In an advantageous embodiment, the electric heating element may be formed as a PTC heating element. The PTC heating element is an already established component, which is characterized in particular by its simple structure. Thus, the electric heating element can be provided very easily, which can detect both precipitation on the first energy transmission component and objects, in particular metallic, which are arranged in the air gap. By means of the heating effect of the PTC heating element, precipitation or snow, rain or other moisture can likewise be removed from the first energy transmission component very easily.

According to a further advantageous embodiment of the invention, the electric heating element may be formed as a heating foil, which is arranged on the first energy transmission component. In this case, the heating element comprises, for example, at least one electrical, that is to say electrically operable heating part, which can be designed as a resistance heating element, in particular as a heating wire. Furthermore, the heating foil comprises at least one film element, which forms, for example, a film layer, which may be inherently dimensionally stable or limp. In this case, the heating part is held on the film element, in particular at least partially, preferably at least predominantly, arranged in the film element formed, for example, from a plastic. As a result, the heating element can be arranged particularly easily on the first energy transmission component. Also, the heating foil can be easily replaced if possible damage, whereby the construction cost can be kept very low.

In a further advantageous embodiment, the electric heating element may comprise heating wires, which are arranged meandering. By means of the meandering shape, a plurality of mutually parallel main sections and, on the other hand, shorter connecting sections can be realized. The connecting sections can each end of two connect adjacent main sections together. In a current flow through the respective heating wire, the current directions in the adjacent main sections are opposite to each other. With this shape, the respective heating wire can closely cover a surface, for example, between a coil of the first energy transmission component and a surface of a housing of the first energy transmission component to be monitored, without a high voltage being induced in the heating wires in the inductive energy transmission or significantly impairing the energy transmission through the heating wires becomes.

Also part of the invention is a method for operating a charging device according to the invention. In the method, precipitation and objects arranged between the first energy transmission component and the second energy transmission component are detected by means of the electrical heating element. Furthermore, precipitation or objects arranged between the energy transfer components can be removed by means of the heating element. Alternatively or additionally, it is conceivable that the inductive energy transfer, that is, the inductive charging interrupted or terminated when objects between the energy transfer components or precipitation on the first energy transfer component is detected, so that destruction or damage of the charging device can be prevented.

Further advantages, features and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of the figures and / or in the figures alone can be used not only in the respectively specified combination but also in other combinations or in isolation, without the scope of To leave invention.

Showing:

1 a schematic side view of a motor vehicle and a loading device according to the invention in detail; and

2 a schematic plan view of a designed as a heating foil electrical heating element of the charging device.

In the figures, identical or functionally identical elements are provided with the same reference numerals.

1 shows a detail of a schematic side view of a presently designed as a passenger car motor vehicle 10 , The car 10 is doing a parked state. The car 10 has a drive train by means of which the motor vehicle 10 is drivable. This includes the car 10 at least one electric machine, by means of which the motor vehicle 10 is drivable. To drive the motor vehicle 10 the electric machine, which is also referred to as a traction machine, operated in an engine operation as an electric motor. The car 10 In this case, it comprises at least one electrical energy store designed, for example, as a battery for storing electrical energy or electric current.

In order to operate the electric machine in its engine operation, the electric machine is supplied with energy stored in the energy store. In this case, the energy store is designed, for example, as a high-voltage energy store (HV energy store). This means that the energy store has an electrical voltage, in particular an electrical operating voltage, of more than 50 volts, in particular more than 100 volts. For example, the energy store has an electrical voltage of several 100 volts, so that particularly high electrical power for driving the motor vehicle 10 can be realized. The car 10 is thus designed as a hybrid or electric vehicle.

By supplying the electric machine with electrical energy from the energy storage decreases its state of charge, that is stored in the energy storage amount of electrical energy. In order to charge the energy storage, that is to store electrical energy in the energy storage, for example, the electric can be operated in a generator mode as a generator, especially when the car moves and rolls over its wheels on a roadway. The generator is doing by the rolling on the road wheels of the moving motor vehicle 10 and thus of kinetic energy of the motor vehicle 10 driven. In this case, at least part of the kinetic energy is converted into electrical energy by means of the generator, which is provided by the generator and stored in the energy storage. By converting the kinetic energy into electrical energy, the car becomes 10 for example, braked.

To the energy storage of the motor vehicle 10 alternatively or in the parked state of the motor vehicle 10 to charge is one in total with 12 designated loading device 12 intended. By means of the loading device 12 can the energy storage inductively charged, that is charged. For this an inductive energy transfer takes place, which will be explained in more detail below. The loading device 12 in this case comprises a first energy transmission component designed as a primary coil 14 , which are on a ground on which the car 10 parked, is arranged.

Furthermore, a secondary energy transmission component designed as a secondary coil is provided 16 of the motor vehicle 10 provided, which at least indirectly to a structure, in particular on the body of the motor vehicle 10 kept and thus with the car 10 is movable relative to the primary coil. In this case, the secondary coil (energy transfer component 16 ) Component of the charging device 12 be.

For charging the energy storage by means of the charging device 12 becomes the car 10 aligned and parked relative to the primary coil such that the energy transfer components 14 and 16 at least partially arranged one above the other. In this case, at least a portion of the primary coil in the vehicle vertical direction is covered upwards by the secondary coil. Furthermore, there are the energy transfer components 14 and 16 spaced apart, so that between them an at least in the vehicle vertical direction extending air gap 24 is arranged.

The primary coil is, for example, electrically with respect to the car 10 external power source, in particular a power grid connected, and is powered by the power source with electrical energy or electrical power. At least part of the electrical energy used to supply the primary coil from the power source is transferred from the primary coil to the secondary coil - through the air gap 24 across - inductively transmitted. In this case, for example, forms in the air gap 24 a magnetic field between the energy transfer components 14 and 16 out. The secondary coil is electrically coupled to the energy storage of the motor vehicle, so that at least part of the energy transmitted inductively from the primary coil to the secondary coil is transferred from the secondary coil to the energy store and stored in the energy store.

The loading device 12 further comprises at least one particularly good 2 recognizable electric heating element, which serves as a heating foil 18 is trained. In this case, the heating foil, in particular flat, on the second energy transfer component 14 arranged. The heating foil 18 includes, for example, a film element 34 , which is form-labile or sluggish. Furthermore, the heating foil comprises 18 at least one on the film element 34 held PTC heating element 26 , which is also referred to as PTC element. By supplying the heating foil 18 , in particular of the PTC heating element 26 , with electric current is the heating foil 18 , in particular the PTC heating element 26 , heated, whereby the primary coil can be at least partially heated or heated. In particular, at least a part of a surface of a housing of the primary coil can be heated, wherein in the housing, for example, electrical components of the first energy transfer component 14 are arranged.

Out 2 is particularly well recognizable that the PTC heating element 26 is arranged in a meandering manner in the manner of resistance heating elements in the form of heating wires or in a meandering manner along the film element 34 extends. In this case, the PTC heating element has 26 a plurality of mutually parallel main sections 30 on. Furthermore, in this case, the PTC heating element 26 opposite to the main sections 30 shorter connecting sections 32 on, wherein a connecting section 32 two adjacent main sections 30 connects to each other and a current flow through the main sections 30 and the connecting sections 32 allows, with respective directions, along which the current through each adjacent main sections 30 flows, in these neighboring main sections 30 are opposite to each other. Due to the shape or extension of the PTC heating element 26 a close-meshed heating of the primary coil, in particular its surface, can be realized. By heating the primary coil, for example, precipitation such as snow, rain and moisture can be removed from the primary coil, in particular from its surface.

In order to improve the energy transfer from the primary coil to the secondary coil in a particularly simple manner, in particular with only a low construction cost, and thus particularly cost-effectively, the electrical heating element (heating foil 18 ) is adapted to precipitate on the first energy transfer component 14 and between the energy transfer components 14 and 16 any arranged objects 20 capture. In particular, by means of the electric heating element objects 20 , in particular metallic objects, located in the air gap 24 be located, recognized or recorded.

In the 1 With 20 designated, in the air gap 24 arranged objects represent interference, which by means of the heating foil 18 , in particular by means of the PTC heating element 26 , can be recorded. For detecting the disturbances and / or the precipitation on the primary coil, the electric heating element, in particular the PTC heating element 26 , operated as a capacitive sensor. The example metallic objects 20 or the Precipitation can or may be a capacitance change, for example between the heating foil 18 , in particular of the PTC heating element 26 , And at least one other component such as the secondary coil cause. For example, the heating foil 18 an electronic computing device 22 assigned, which is also referred to as a control unit. By means of the control unit is the heating foil 18 , in particular the PTC heating element 26 , driven and thereby operated as a capacitive sensor, the control unit with the heating foil 18 can be electrically connected. By means of the control device, the previously described, by the objects 20 and / or the precipitation caused capacitance change of the capacitive sensor are detected so that it can be deduced that, for example, the objects as a result of detecting the capacitance change 20 in the air gap 24 between the energy transfer components 14 and 16 are located. If this is the case, an interruption or termination of the inductive charging can be effected by means of the control device in order to damage the charging device 12 to avoid.

The control unit is further adapted to the heating foil 18 to control accordingly, so when detected precipitation, the heating foil 18 is supplied with electrical energy, causing it to heat the heating foil 18 and thus the primary coil comes. This allows the precipitate, which is snow for example, to be removed.

The PTC heating element 26 is thus in particular designed to detect changes in the magnetic field, in particular capacitance changes, these changes being caused by the objects 20 and / or can be effected by precipitation on the primary coil. At one end of the heating foil 18 is a cable 28 arranged, which is the heating foil 18 , in particular the PTC heating element 26 , with the electronic computing device 22 combines. About the cable 28 For example, at least one signal characterizing the capacitance change can be transmitted to the control unit and received by the control unit, so that the capacity change can be detected by means of the control unit on the basis of the signal.

LIST OF REFERENCE NUMBERS

10

motor vehicle

12

loader

14

first energy transfer component

16

second energy transfer component

18

heating film

20

objects

22

control device

24

air gap

26

PTC heating element

28

cable connection

30

main section

32

connecting portion

34

film element

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 102011076186 A1 [0002]
• DE 102012103321 A1 [0004]

Claims (5)

Loading device ( 12 ) for inductively charging an energy storage device of a motor vehicle ( 10 ) with electrical energy, with at least one first energy transfer component ( 14 ), via which energy to at least one second energy transfer component ( 16 ) of the motor vehicle ( 10 ) is inductively transferable, and with at least one electrical heating element for at least partial heating of the first energy transfer component ( 14 ), characterized in that electrical heating element is adapted to precipitate on the first energy transfer component ( 14 ) and between the energy transfer components ( 14 . 16 ) arranged objects ( 20 ) capture. Loading device ( 12 ) according to claim 1, characterized in that the electric heating element as a PTC heating element ( 26 ) is trained. Loading device ( 12 ) according to claim 1 or 2, characterized in that the electric heating element as a heating foil ( 18 ) formed on the first energy transfer component ( 14 ) is arranged. Loading device ( 12 ) according to one of the preceding claims, characterized in that electrical heating element heating wires ( 34 ), which are arranged meandering. Method for operating a charging device ( 12 ) according to any one of the preceding claims.

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