DE102014221884A1 - Sensor arrangement for providing additional information in an inductive charging system - Google Patents

Abstract

The invention relates to a sensor arrangement for providing additional information in an inductive charging system comprising a detection device (4), which is provided for detecting an electrically conductive foreign body, a monitoring device (5), which for monitoring a relative position between a primary coil (2) and a secondary coil (3) is provided, and a communication unit (6). In order to minimize costs, space requirements and power consumption for the obligatory additional systems, it is proposed that the detection device (4), the monitoring device (5) and the communication unit (6) are integrated together to form a sensor arrangement, at least one assembly being provided for common use.

Description

The invention relates to a sensor arrangement for providing additional information in an inductive charging system, comprising a detection device which is provided for detecting an electrically conductive foreign body, a monitoring device which is provided for monitoring a relative position between a primary coil and a secondary coil, and a communication unit.

The invention further relates to a sensor system for providing additional information in an inductive charging system, which has a primary coil on a primary side, a secondary coil on a secondary side and at least one such sensor arrangement.

The invention further relates to an inductive charging system which has at least one such sensor system.

The invention also relates to a method for providing additional information in an inductive charging system by means of at least one such sensor system.

Such a sensor arrangement is used in an inductive charging system with high transmission power, in particular when wirelessly charging batteries in electric cars or hybrid cars. In an inductive charging system, the electrical energy is transmitted by means of an alternating magnetic field, for example at 85 kHz, from a primary coil to a secondary coil via an air gap. In this method, in addition to the actual energy transfer, there are a number of additional, partly safety-relevant, functions that are required for a controlled sequence of the charging process.

When charging the battery of the electric vehicle must be prevented that can pass in the large air gap between the primary coil and the secondary coil electrically conductive body. As a result of the action of the charging field on the electrically conductive body located in the air gap, it can be heated by eddy currents. In the worst case, for example, metal-coated plastics or metal-coated papers may self-ignite the body. Therefore, it must be ensured that metal bodies located in the air gap do not heat up and possibly ignite adjacent flammable materials

Another necessary functionality is the continuous monitoring of the correct relative position between the primary coil and the secondary coil of the inductive charging system, which are transformer coupled via an air gap. This ensures that the requested charging power can be transmitted with sufficient efficiency.

In addition, wireless data communication must be established for the transfer of data required for the charging process between the primary coil and the secondary coil.

From the not yet published German patent application DE 10 2014 207 253.0 a device for checking a presence of an electrically conductive body with at least one transmitting device for providing a transmission signal in the form of a magnetic field is known.

The invention has for its object to provide a sensor arrangement of the type mentioned for an inductive charging system, in which the costs, space requirements and power consumption for the mandatory additional systems are minimized.

This object is achieved by a sensor arrangement of the type mentioned above in that the detection device, the monitoring device and the communication unit are integrated together to form a sensor arrangement, wherein at least one module is provided for sharing.

In the detection device is a device for detecting electrically conductive foreign objects, for example in the air gap between the primary coil and the secondary coil, which can interfere with the charging process and / or represent a security risk by a possible auto-ignition. These electrically conductive foreign bodies may be made of metal or another electrically conductive material. The monitoring device is a device which checks the relative position between the primary coil and the secondary coil so that the required electrical energy can be transmitted with sufficient efficiency. The communication unit is responsible for the transmission of data, for example the current state of charge of the battery, between the primary side and the secondary side of the inductive charging system. Integration means that the detection device, the monitoring device and the communication unit are combined to form a sensor arrangement and share at least parts of the electronics and infrastructure.

Furthermore, the object is achieved by an above-mentioned sensor system, wherein the detection device for detecting an electrically conductive foreign body in an air gap between the primary coil and the Secondary coil is provided, the monitoring device is provided for monitoring a relative position between the primary coil and the secondary coil and the communication unit is provided for transmitting data between the primary side and the secondary side.

Furthermore, the object is achieved by an inductive charging system mentioned above, which has at least one such sensor system.

Furthermore, the object is achieved by an above-mentioned method for providing additional information in an inductive charging system by means of at least one such sensor system.

The advantages of the invention are in particular that the combination of functions leads to a reduction in the cost of the additional systems and minimizes the space requirement and power consumption.

In a preferred embodiment, the monitoring device and the communication unit are integrated into the detection device. This is particularly advantageous since both the coil arrangement and the signal conditioning unit of the detection device are used by the monitoring device and the communication unit. This reduces the complexity of the hardware, which reduces costs, space requirements and power consumption.

In a further advantageous embodiment, the detection device is provided for detecting a secondary coil. Since the secondary coil consists of detectable material, it is detectable by the detection device, like a foreign body. This is particularly advantageous since the detection device fulfills both functionalities and therefore no additional electronics are required.

In a further embodiment, the monitoring device has means for pattern recognition, which are provided for determining a relative position between a primary coil and a secondary coil. Pattern recognition is the ability to detect regularities, repetitions, similarities or laws in a set of data.

This is particularly advantageous since the relative position between the primary coil and the secondary coil can be determined precisely with the aid of pattern recognition algorithms.

In a particularly advantageous embodiment, the secondary coil is resonantly tuned to the monitoring frequency and / or the communication frequency. The monitoring frequency is the frequency used by the monitoring device to determine and monitor the relative position between the primary coil and the secondary coil. The communication frequency is the frequency with which data is transmitted between the primary side and the secondary side via the communication unit. The resonant tuning has the advantage that the range for monitoring the relative position between the primary coil and the secondary coil and for the communication increases.

In a further advantageous embodiment, the detection device, the monitoring device and the communication unit are provided for the same frequency range. This has the advantage that large parts of the electronics and infrastructure of the sensor system can be shared by the detection device, the monitoring device and the communication unit.

In an advantageous embodiment, the secondary side has at least one additional coil, wherein the at least one additional coil and the secondary coil have a defined relative position. Since the relative position between the secondary coil and the at least one additional coil is known, the at least one additional coil can be used to monitor the relative position between primary coil and secondary coil. Due to the fact that the at least one additional coil, like the secondary coil, does not have to be optimized for the charging process, the monitoring of the relative position can be carried out more accurately. In addition, the charging process, the relative position monitoring and the communication with the use of different coils influence less or not at all and the susceptibility to interference decreases.

In a particularly advantageous manner, the at least one additional coil has a tuning network and a switch, wherein the at least one additional coil is tuned resonantly with the tuning network and the switch is provided for connecting the tuning network. By the resonant vote, for example, on the detection frequency, the accuracy of the relative position determination increases.

In a further embodiment, the secondary side has at least one backscatter modulator which is provided for amplifying and modulating a detection signal. This makes it possible to achieve an improvement in recognizability in the detection of an electrically conductive foreign body on the secondary side.

In an advantageous embodiment, an independent communication transmitter is connected to the secondary coil. This has the advantage that the existing hardware for the charging process is not modified, which minimizes the risk of implementing the additional functions on the secondary side. In addition, the ease of maintenance improves when using a dedicated transmitter on the secondary side.

In a further advantageous embodiment, the backscatter modulator is provided for the transmission of data between the secondary side and the primary side. This also has the advantage that the existing hardware for the charging process is not modified. By using the existing backscatter modulator for data transmission, the costs are additionally reduced.

In the following the invention will be described and explained in more detail with reference to the embodiments illustrated in the figures.

Show it:

1 a block diagram of a sensor arrangement for providing additional information for an inductive charging system, which is integrated in a detection device and

2 a block diagram of an inductive charging system with a sensor system for providing additional information.

1 1 shows a block diagram of a sensor arrangement for providing additional information for an inductive charging system, which is incorporated in a detection device (FIG. 4 ) is integrated. The sensor arrangement has a detection device 4 , which is provided for detecting an electrically conductive foreign body, a monitoring device 5 which is used to determine and monitor a relative position between a primary coil 2 and a secondary coil 3 is provided, and a communication unit 6 on.

The detection device 4 has a coil arrangement 4a and a signal conditioning unit 4b which has a first physical interface 12a , For example, a cable or an optical waveguide, with an evaluation 12 connected is. By the detection device 4 an alternating magnetic field is generated in the MHz range, which induces eddy currents in a conductive, such as metallic, foreign body, which then in turn generate a detectable magnetic field. This magnetic field generated by the foreign body can be detected by the detection device 4 be recognized. Since a foreign body could heat up or ignite during the charging process, the detection of electrically conductive foreign bodies, which is also called "foreign object detection", short FOD, is a safety-related and thus mandatory additional function for the inductive charging system. For example, the FOD takes place at 3.75 MHz.

The monitoring device 5 which means 5a for pattern recognition, and the communication unit 6 are in the signal conditioning unit 4b the detection device 4 integrated and form a common sensor array. As the monitoring of the relative position between the primary coil 2 and the secondary coil 3 and the transfer of data between the primary page 15 and the secondary side 16 takes place in the same frequency range as the detection of electrically conductive foreign bodies, the coil arrangement 4a and the signal conditioning unit 4b also used for relative position monitoring and data transmission. In this case, the detection signals for the detection of electrically conductive foreign bodies for determining the relative position of the secondary coil 3 to the coil arrangement 4a used, the relative position between the primary coil 2 and the coil assembly 4a is known. With the help of the pattern recognition algorithms can then the relative position between the primary coil 2 and the secondary coil 3 determined precisely from the detection signals in a grid and over the first physical interface 12a to the evaluation unit 12 to get redirected. Data, such as the current state of charge of the battery during the inductive charging, incoming power and / or sensor data are also from the coil assembly 4a received from the signal conditioning unit 4b prepared and via the first physical interface 12a to the evaluation unit 12 forwarded.

2 shows a block diagram of an inductive charging system with a sensor system for providing additional information. The sensor system 1 has a primary page 15 arising from the sensor arrangement described above, which in the detection device 4 integrated, and a primary coil 2 , which with a power signal for the inductive charging of a power signal transmission electronics 13 via a second physical interface 13a is fed, composed. The sensor system 1 also has a secondary page 16 on which is located on the vehicle to be loaded and a secondary coil 3 to which an independent communications channel 7 , a backscatter modulator 8th and at least one additional coil 9 via a switch 10 are connected. The power signal is from the primary coil 2 over an air gap 11 to the secondary coil 3 transmitted on a frequency in the kHz range, for example at 85 kHz. About a third physical interface 14a the power signal becomes power signal receiving electronics 14 forwarded where it rectified and the battery, which is designed for example in lithium-ion technology, provided for the charging process. The detection device 4 for detecting an electrically conductive foreign body in the air gap 11 ensures that the charging process is safe and undisturbed. The monitoring device 5 for monitoring the relative position between the primary coil 2 and the secondary coil 3 during charging ensures that the transformer coupling between the charging coils 2 . 3 over the air gap 11 is optimally designed so that the energy can be transmitted efficiently and according to the charging algorithm. To increase the range and better visibility of the secondary side 16 There is an additional coil on the vehicle 9 which has a voting network 9a resonantly tuned, has been installed. With a switch 10 lets go the voting network 9a for the one extra coil 9 switch on and off as required. A further improvement in recognizability can be achieved by using an active backscatter modulator 8th achieve. On the secondary side 16 becomes an additional communication transmitter independent of foreign object recognition 7 used while receiving via the already existing signal conditioning unit 4b he follows.

The invention relates to a sensor arrangement for providing additional information in an inductive charging system comprising a detection device 4 , which is provided for detecting an electrically conductive foreign body, a monitoring device 5 which is used to monitor a relative position between a primary coil 2 and a secondary coil 3 is provided, and a communication unit 6 , In order to minimize costs, space requirements and power consumption for the obligatory additional systems, the detection device is proposed 4 , the monitoring device 5 and the communication unit 6 are integrated together to form a sensor arrangement, wherein at least one module is provided for common use.

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 102014207253 [0009]

Claims (15)

Sensor arrangement for providing additional information in an inductive charging system comprising a - detection device ( 4 ), which is provided for the detection of an electrically conductive foreign body, - a monitoring device ( 5 ) which is used to monitor a relative position between a primary coil ( 2 ) and a secondary coil ( 3 ), and - a communication unit ( 6 ), characterized in that the detection device ( 4 ), the monitoring device ( 5 ) and the communication unit ( 6 ) are integrated together to a sensor arrangement, wherein at least one module is provided for common use. Sensor arrangement according to claim 1, characterized in that the monitoring device ( 5 ) and the communication unit ( 6 ) in the detection device ( 4 ) are integrated. Sensor arrangement according to one of the preceding claims, characterized in that the detection device ( 4 ) for detecting a secondary coil ( 3 ) is provided. Sensor arrangement according to one of the preceding claims, characterized in that the monitoring device ( 5 ) Medium ( 5a ) for pattern recognition, which is used to determine a relative position between a primary coil ( 2 ) and a secondary coil ( 3 ) are provided. Sensor system ( 1 ) for providing additional information in an inductive charging system comprising a primary coil ( 2 ) on a primary page ( 15 ), - a secondary coil ( 3 ) on a secondary side ( 16 ) and - at least one sensor arrangement according to claims 1 to 4, wherein - the detection device ( 4 ) for detecting an electrically conductive foreign body in an air gap ( 11 ) between the primary coil ( 2 ) and the secondary coil ( 3 ), - the monitoring device ( 5 ) for monitoring a relative position between the primary coil ( 2 ) and the secondary coil ( 3 ) and - the communication unit ( 6 ) for the transmission of data between the primary side ( 15 ) and the secondary side ( 16 ) is provided. Sensor system ( 1 ) according to claim 5, characterized in that the secondary coil ( 3 ) is resonantly tuned to the monitoring frequency and / or the communication frequency. Sensor system ( 1 ) according to one of claims 5 to 6, characterized in that the detection device ( 4 ), the monitoring device ( 5 ) and the communication unit ( 6 ) are provided for the same frequency range. Sensor system ( 1 ) according to one of claims 5 to 7, characterized in that the secondary side ( 16 ) at least one additional coil ( 9 ), wherein the at least one additional coil ( 9 ) and the secondary coil ( 3 ) have a defined relative position. Sensor system ( 1 ) according to one of claims 5 to 8, characterized in that the at least one additional coil ( 9 ) a voting network ( 9a ) and a switch, wherein the at least one additional coil ( 9 ) with the voting network ( 9a ) is resonantly tuned and the switch ( 10 ) for connecting the tuning network ( 9a ) is provided. Sensor system ( 1 ) according to one of claims 5 to 9, characterized in that the secondary side ( 16 ) at least one backscatter modulator ( 8th ) provided for amplifying and modulating a detection signal. Sensor system ( 1 ) according to one of claims 5 to 10, characterized in that at the secondary coil an independent communication transmitter ( 7 ) connected. Sensor system ( 1 ) according to claim 11, characterized in that the independent communication transmitter ( 7 ) for the transmission of data across the air gap ( 11 ) to the communication unit ( 6 ) is provided. Sensor system ( 1 ) according to any one of claims 5-10, characterized in that the backscatter modulator ( 8th ) for the transmission of data between the secondary side ( 16 ) and the primary page ( 15 ) is provided. Inductive charging system, which has at least one sensor system ( 1 ) according to claims 5 to 13 for providing additional information. Method for providing additional information in an inductive charging system by means of at least one sensor system ( 1 ) according to claims 5 to 13.

Images