Wireless charging system and metal foreign body detection method thereof

Abstract

The invention discloses a wireless charging system and a metal foreign body detection method thereof. A wireless charging device and an electrical appliance are arranged in a charging area; the wireless charging device is mainly composed of a signal conversion module, a controller and a transmitting antenna, and the signal conversion module is respectively connected with the transmitting antenna for transmitting signals and the controller and is also connected with a power supply end; the electrical appliance comprises a receiving end coil and a rectifier, and the receiving end coil is connected with the rectifier, and the electrical appliance outputs generated current through an output end. According to the wireless charging system and the metal foreign body detection method thereof, before or when the wireless charging device starts wirelessly charging the electrical appliance, the controller of the wireless charging device can detect a power consumption situation, voltage / current information and phase difference information of the transmitting antenna to instantly judge whether a metal foreign body invades; therefore, device damage and dangers due to high temperature generated by the metal foreign body are avoided, and a purpose of improving wireless charging safety is implemented.

Description

technical field [0001] The invention relates to a wireless charging system, in particular to a wireless charging system and a metal foreign object detection method thereof. Background technique [0002] The current wireless charging technology is mainly based on near-field induction. A charger for wireless charging transmits energy to an electric device within a predetermined charging area, and the electric device uses the received energy to charge its battery. Charging, and at the same time for the use of the electrical equipment itself, the principle of energy transmission is to install a coil in the charger and generate an alternating electromagnetic field through alternating current, and another coil is installed at one end of the electrical equipment to receive the alternating electromagnetic field, and the It is converted into electrical energy and stored in the battery of the electric device. Therefore, wireless charging technology can indeed improve the convenience o...

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Problems solved by technology

[0005] It can be known from the above prior art that if a metal foreign object invades the charging area, the metal foreign object will generate high temperature due to charging, making the possibility of danger and equipment damage very high. However, the external sensor in the prior art It is easy to affect the performance of power transmission. The foreign object detection technology of the power transmission coil will be affected by the difference in the transmission distance and cannot accurately determine whether there is a foreign object. The complex structure of the component makes the manufacturing cost higher, and the difference between the corresponding characteristics of the resonant frequency is used as the basis for the presence of foreign matter, and it is still impossible to efficiently and accurately judge whether there is really a metal foreign matter. Therefore, The existing metal foreign object detection technology still has problems such as being affected by changes in transmission distance, high accuracy, and high manufacturing costs. It is really necessary to propose a more ideal solution

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