Delta Electronics (thailand) Public Company Limited

Delta Electronics (thailand) Pcl.

Jonas Enderlin

Ulrich Richter

Luca König

Michael Mentele

Yibo Wang

A foreign object detection device for a wireless power transfer system for inductive power transfer from a primary part to a secondary part across an airgap, includes a sensor module with a multitude of detection cells. In order detect a foreign object near a detection cell, a stimulation signal is applied to a detection cell by means of a stimulation unit and the time response of the detection cell is measured with a measurement unit and compared to a reference time response of that detection cell that has been previously sensed by a control and signal processing unit.

Foreign object detection

Provided are a sensor arrangement for a foreign object detection device for a wireless power transfer system, a foreign object detection and a primary part for a wireless power transfer system. The sensor arrangement includes multiple detection cells, each including a sense coil including a winding spirally wound in a plane and having multiple turns. Multiple input leads and one or more output leads are provided such that each detection cell may be connected to a current input and a current output. The sense coil of at least one detection cell includes an outer coil section and an inner coil section arranged inside the outer coil section, where a first distance between an outermost turn of the inner coil section and an innermost turn of the outer coil section is at least twice a largest distance between two turns of the outer coil section.

Sensor arrangement for a foreign object detection device

A wireless power transfer arrangement () for a wireless power transfer across an airgap () by inductive coupling, for example for charging the battery () of an electric vehicle, includes a primary side () with a primary pad () for generating a magnetic field () into the airgap () and a secondary side () arranged on the other side of the airgap () that picks up the magnetic field () and provides the energy received through the magnetic field () to the battery (). The primary side () is for example installed at a charging station and the secondary side () is comprised by the electric vehicle. In order to control the charging process during the power transfer, a wireless communication channel () is provided between the primary () and the secondary () by means of two wireless transceivers (). According to the invention, the wireless transceivers () are adapted such that their communication range is less than twice a largest spatial extent of the primary pad. In this way, the communication between the charging station and the vehicle may not be received by other charging stations or vehicles located at the same charging area. And if the other vehicles and other charging stations of the same charging area are adapted according to the invention as well, their communication does not interfere with each other or otherwise disturb each other such that a complex and laborious pairing process may be avoided.

Wireless power transfer arrangement

The invention relates to a sensor arrangement () for a foreign object detection device which includes a current input () and a current output (), a multitude of detection cells (-), each comprising a sense coil and a capacitive element, forming a resonant tank. The sensor arrangement () further has a multitude of inputs leads (-) and a multitude of output leads (-), the total number of input and output leads being equal or smaller than the number of detection cells (-). Each detection cell is connected between one of the input leads (-) and one of the output leads (-), in a way that each of the detection cells (-) is connected to a different pair of input and output leads (--). An input selection circuit () allows to selectively establish an electrical connection between the current input () and one or more of the input leads (-) and an output selection circuit to () selectively establish an electrical connection between one or more of the output leads (-) and the current output (). According to the invention at least one detection cell (-) includes a decoupling element (D-D) connected in series to its resonant tank. The invention further relates to foreign object detection device for a wireless power transfer system, a primary part of a wireless power transfer system, a wireless power transfer system and a method for detecting a foreign object.

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Teningen, Germany

Jonas Enderlin