WO2017092950A1

WO2017092950A1 - Method for operating a monitoring device for monitoring an inductive energy transmission device

Info

Publication number: WO2017092950A1
Application number: PCT/EP2016/076387
Authority: WO
Inventors: Gabriel Krein; Philipp Schumann
Original assignee: Robert Bosch Gmbh
Priority date: 2015-12-02
Filing date: 2016-11-02
Publication date: 2017-06-08
Also published as: TW201729511A; DE102015224013A1

Abstract

The invention relates to a method for operating a monitoring device for monitoring an inductive energy transmission device by at least one transmitter coil transmitting to at least one receiver coil arranged at a distance from the at least one transmitter coil. The monitoring device has a data storage unit in which a reference characteristic map U_ij,meas-ref based on offset parameters dx, dy, dz between the transmitter coil and the receiver coil is stored. In a first method step (A), the offset parameters dx, dy, dz existing between the transmitter coil and the receiver coil are determined. In a second method step, a voltage U_ij,meas induced by the magnetic field is measured by the coil array with respect to magnitude and phase. In a third method step (C), the ascertained measurement values of the induced voltage U_ij,meas are compared with reference characteristic maps U_ij,meas-ref stored in the data storage unit, and finally in a fourth method step (D), the presence or absence of a foreign object is inferred using the deviations between the measurement values of the induced voltage U_ij,meas and the reference characteristic maps U_ij,meas-ref stored in the data storage unit.

Description

Description title

Method for operating a monitoring device for monitoring an inductive energy transmission device

The present invention relates to a method for operating a

Monitoring device for monitoring an inductive

Energy transmission device.

State of the art

Electric vehicles and hybrid vehicles usually have an electrical energy storage, such as a traction battery, which provides the electrical energy for propulsion. Is this electric

Energy storage fully or partially discharged, so the electric vehicle must control a charging station, where the energy storage can be recharged. So far, it is customary that at such a charging station the

Electric vehicle is connected by a cable connection to the charging station. This connection must usually be made manually by a user. It is also necessary that charging station and

Electric vehicle have a mutually corresponding connection system. Furthermore, occasionally wireless charging systems for electric vehicles or hybrid vehicles are known. For this purpose, an electric vehicle is parked above a transmitting coil (transmitting device) or a charging pad or charging device. This coil emits a high frequency alternating magnetic field. The

alternating magnetic field is from a receiving coil (charging coil or

Receiving device) received within the vehicle and converted into electrical energy. By means of this electrical energy, a traction battery of the vehicle can then be charged. The document DE 10 2011 010 049 AI discloses such a system for charging a vehicle battery, in which the energy is transmitted inductively.

Furthermore, the energy storage of the electric vehicle can also be used for feeding back. For this purpose, a cable connection or an inductive energy or power transmission can also be used.

When wirelessly charging a battery of an electric vehicle is

Typically, the transmitting coil of the transformer either embedded in the street floor or formed as a floor-mounted charging plate (charging pad) and is connected by means of suitable electronics to the mains. The receiving coil of the transformer is typically fixedly mounted in the underbody of the vehicle and in turn by means of suitable electronics with the

Traction battery of the vehicle connected. For energy transmission, the transmitting coil or primary coil generates a high-frequency alternating field, which is the

Reception coil or secondary coil penetrates and induces a corresponding current there. On the one hand, the transmitted power is linear with the

Switching frequency scales, on the other hand, the switching frequency through the

Control electronics and losses in the transmission path is limited, results in a typical frequency range of 30 - 150 kHz.

Between the transmitter coil of the charging station and the receiver coil in the

Vehicle is an air gap. Due to the required ground clearance of motor vehicles, this air gap is a few centimeters. Air gaps in the size of 3-30 cm are very common, if not by measures such as

Lowering the vehicle-fixed coil, the entire vehicle or lifting the stationary coil or a combination of these measures an ideally small air gap is achieved. The resulting in the air gap during the transmission of alternating magnetic fields are suitable for any metallic or electrically conductive objects that are in the air gap, electrical

Induce eddy currents. Ohmic losses heat these so-called foreign objects. This heating is not just for the

Personnel safety, but also for the operational safety of the vehicle one Therefore, it is necessary to limit the heating of an inductive charging system either by limiting the magnetic field or to detect any objects located in the air gap by suitable means and then deactivate the energy transfer until they are removed, or no more danger from you emanates.

Known methods of foreign object detection, for example, expediently consist of conventional metal detectors whose core element is one or more sensor coils. These methods are based on active excitation of the sensor coil / sensor coils and measurement of the change of the sensor coil

Receiving signal in the presence of a metal object or the measurement of a change in the electrical properties of the sensor coil / sensor coils. Inductive charging / inductive power transmission is the application

However, conventional metal detection methods due to the strong magnetic field not trivial, which is why known metal object detection method (MOD) either a short-term shutdown of the energy transfer (and thus of the magnetic main field) or special sensor coil designs (for

Example meander-shaped sensor coils suggest) to perform a metal detection can. Both are associated with significant disadvantages.

There is therefore a need for a more effective and less expensive monitoring device of inductive power transmission devices.

Disclosure of the invention

The inventive method with the characterizing part of claim 1 has the advantages that a short-term shutdown of the energy transfer (and thus of the magnetic main field) with respect to an efficient object recognition is no longer necessary. According to the invention, it is provided that in the method for operating a monitoring device for monitoring an inductive

Energy transmission device of at least one transmitting coil to one of the at least one transmitting coil spaced at least one

Receiving coil, wherein the monitoring device comprises a data memory, in the reference maps Uij.meas-ref depending on

Offset parameters dx, dy, dz are stored between the transmitting coil and the receiving coil, in a first method step (A) the present offset parameters dx, dy, dz between the transmitting coil and the receiving coil are determined. In a second method step (B), a voltage Uij, meas induced by the magnetic field is measured in terms of magnitude and phase by means of the coil array. In a third method step (C), the determined measured values of the induced voltage Uij.meas are compared with reference characteristic diagrams Uij.meas-ref stored in the data memory and finally in a fourth method step (D) on the basis of the deviations between measured values of the induced voltage Uneas and in the data memory stored reference maps U, meas-ref on the arrival or

Absence of a foreign object closed. It is advantageous that the main magnetic field of the energy transfer is explicitly exploited in addition to the charging of a traction battery for metal detection and not only considered parasitic, as is the case with the known methods of the prior art. In other words, the main magnetic field is utilized and need not be turned off for metal detection, thereby ensuring continuous energy transfer. The measures mentioned in the dependent claims advantageous refinements of the method specified in the independent claim are possible.

Advantageously, the voltage induced by the magnetic field Uij.meas is measured by means of a coil array, which is designed to monitor a gap between the at least one transmitting coil and the at least one receiving coil. By using a coil array can be a clear better spatial resolution can be achieved, whereby foreign objects in the field of energy transfer can be better localized.

It is also advantageous that the coil array rests on the transmitting coil or is installed on the top of the transmitting coil. By this arrangement, the monitoring device requires only a very small footprint and can also be run over by the vehicle to be loaded. Additionally / alternatively, another coil array can be installed on the vehicle-side receiver coil, so that monitoring is also ensured by the vehicle forth.

Furthermore, the individual coils of the coil array are made flat. Due to this design, the single coils can be installed very well in a flat charging pad. The geometry of the turns of the individual coils may alternatively have a circular, n-square, square, or cuboid shape.

The reference maps Uij.meas-ref are advantageous depending on

Offset parameters dx, dy, dz (and alternatively depending on others

Operating parameters such as transmission power, etc.) stored in the data memory. These reference characteristic diagrams are advantageously determined by a calibration prior to delivery of the inductive energy transmission device and stored as a function of the offset parameters of the energy transmission device (of the coil system) dx, dy, dz.

Furthermore, it is advantageous that the monitoring device works passively. The passive mode of operation eliminates the need for the monitoring device /

Coil array any type of Anreschaltaltung. As a result, the main magnetic field does not have to be switched off or the energy transfer must be interrupted in order to be able to carry out a metal detection. This makes the energy transfer more efficient and it can be a continuous one

Energy transmission can be ensured. Furthermore, it is advantageous that the transmission coil is deactivated in the presence of a foreign object in the intermediate space or the power is reduced when an intrusion of an object has been detected.

Other features and advantages of the present invention will become

Expert from the following description of exemplary

Embodiments, which should not be construed as limiting the invention, with reference to the accompanying drawings.

Brief description of the drawings

Show it:

Fig. 1: a schematic representation of a vehicle and a

inductive energy transfer device;

2 shows a schematic representation of a coil array.

All figures are merely schematic representations of inventive devices or their components according to embodiments of the

Invention. In particular, distances and size relationships are not shown to scale in the figures. In the various figures, corresponding elements are provided with the same reference numbers.

Figure 1 shows a schematic representation of a vehicle 19, a

Device for inductive energy transmission 10 and a

Monitoring device 13. The vehicle / electric vehicle / hybrid vehicle 19 is in a standing state. The traction battery 18 is over the

Inductive energy transfer device 10 is charged. In this regard, a transmitting coil / transmitting device 11 is embedded in the subfloor 20 and rests on the subfloor 20. The receiving coil / receiving device 12 is in Vehicle 19 arranged - preferably in the underbody of the vehicle 19th

Between transmitting coil 11 and receiving coil 12 is a gap 14, also called air gap 14. The monitoring device 13 is arranged in this intermediate space 14 and preferably lies on the transmitting coil 11. The monitoring device 13 comprises a coil array 15, which has individual coils 16.1, 16.2,... 16n.

During operation of the inductive power transmission device 10, the main magnetic field extending between the transmitting coil 11 and the

Reception coil 12 is formed, exploited for metal detection and not considered as parasitic. Furthermore, the inductive energy transmission device 10 has a data memory 17. In this data memory 17 are

Reference maps Uij.meas-ref as a function of offset parameters dx, dy, dz, resulting from the offset between the transmitting coil 11 and receiving coil 12, stored. These reference characteristics are determined by a calibration prior to delivery of the device for inductive energy transfer by using the coil array 15, the induced voltages U, meas-ref for different positions of the transmitting coil 11 and the receiving coil 12th

be recorded. The spatial offset parameters dx, dy, dz result from the fact that the receiving coil is shifted horizontally in the X and Y directions relative to the transmitting coil 11 located in the bottom 20 as well as vertically in the Z direction relative to the transmitting coil 11. The detection of the presence or absence of a foreign object will now be as follows

proceeded: First, in a first step A, the present

Offset parameters dy, dy, dz between the transmitting coil 11 and the receiving coil 12 are determined. This measurement determines how much the receiver coil differs from the original calibration in the horizontal and vertical directions from the original calibration ex works. Subsequently, in a second method step B, a voltage Uij, meas induced by the magnetic field is measured in terms of magnitude and phase by means of the coil array. In a third method step C, the determined measured values of the voltage Uij.meas induced in the coil array are stored in the data memory 17 Reference maps Uij.meas-ref compared. Finally, in a fourth method step D, reference is made to the presence or absence of a foreign object on the basis of the deviation between measured values of the induced voltage Uij.meas and reference characteristic maps stored in the data memory at Uij, meas-ref. It is also quite another course of the process conceivable. Thus, first, by means of the coil array in a method step A, the induced voltages Uij, meas can be measured with magnitude and phase in all individual coils of the coil array 15. These measured values of the induced voltages Uij.meas are finally compared with previously stored reference characteristic diagrams Uij.meas-ref, wherein the

Reference maps determined by a calibration before delivery of the system for inductive energy transmission 10 and in dependence of

Offset parameters dx, dy, dz of the energy transmission device are stored. Now it must be distinguished. In the first case, the displacement situation that is actually present during the measurement is known. In this case, the relevant reference values can be taken directly from the stored maps (possibly by interpolation between interpolation points).

In the second case, the displacement situation that is actually present during the measurement is unknown. The offset situation (offset parameters dy, dy, dz) present during the specific measurement can be determined from the comparison with the stored reference characteristic diagrams. In this case, the possible deviation from the reference due to a metallic object is of no importance because it is present only on one sensor coil or a few sensor coils / individual coils of the coil array (15) (depending on the size of the foreign object) and all other individual coils of the coil array "correct". In the case of a significant deviation from the reference distribution of the stresses for the actual displacement situation determined in the present two cases, the presence of a

closed metallic foreign object.

The distribution of the magnetic field on the different individual coils of the

Sensor arrays is from the offset situation and those in the two

Power transmission coils (transmitting coil / receiving coil) excited currents dependent. This method can also be independent of the metal detection or Fremdobjekterkennung to determine the coil offset between

Transmitter coil 11 and receiving coil 12 are used, as well as for

Vehicle positioning are used.

5

Figure 2 shows a schematic representation of the coil array 15. Same

Elements with respect to Figure 1 are provided with the same reference numerals and are not explained in detail. Shown are the individual coils Uli, U12, U13, etc., which act as sensor coils in the coil array, this being constructed as a coil plate l o.

Claims

Claims 1. A method for operating a monitoring device (13) for

Monitoring an inductive energy transmission device (10) of at least one transmitting coil (11) to one of the at least one transmitting coil (11) spaced at least one receiving coil (12), wherein the monitoring device (13) comprises a data memory (17), in the reference characteristic Uij. meas-ref depending on

Offset parameters dx, dy, dz between transmission coil (11) and

Receiving coil (12) are stored, characterized in that

in a first process step (A), the present invention

Offset parameters dx, dy, dz are determined between the transmitter coil (11) and the receiver coil (12),

in a second method step (B), a voltage Uij.meas induced by the magnetic field is measured in terms of magnitude and phase by means of the coil array (15),

in a third method step (C) the determined measured values of the induced voltage Uij.meas are stored in the data memory (17)

Reference maps Uij.meas-ref are compared and

- In a fourth step (D) on the basis of the deviations between measured values of the induced voltage Uij.meas and stored in the data memory (17) reference maps U, meas-ref is closed to the presence or absence of a foreign object.

2. Method for controlling a monitoring device (13) according to

Claim 1, characterized in that the induced by the magnetic field voltage Uij.meas by means of a coil array (15) is measured, which is adapted to a gap (14) between the at least one transmitting coil (11) and the at least one

Monitor receiving coil (12).

3. A method for controlling a monitoring device (13) according to any one of the preceding claims, characterized in that the coil array (15) rests on the transmitting coil (11).

4. A method for controlling a monitoring device (13) according to any one of the preceding claims, characterized in that the

Individual coils of the coil array (15) are made flat and the

Alternatively, the geometry of the turns of the individual coils can have a circular, n-square, square or cuboid shape.

5. A method for controlling a monitoring device (13) according to one of the preceding claims, characterized in that the

Reference maps Uij.meas-ref depending on offset parameters dx, dy, dz are stored in the data memory (17).

6. A method for controlling a monitoring device (13) according to any one of the preceding claims, characterized in that the

Monitoring device operates passively, i. An active starter circuit is eliminated.

7. A method for controlling a monitoring device (13) according to any one of the preceding claims, characterized in that the

Transmitter coil (11) is deactivated in the presence of a foreign object in the intermediate space (14) or the power is reduced when an intrusion of an object has been detected.