CN-122026638-A - Wireless power transmitter

CN122026638ACN 122026638 ACN122026638 ACN 122026638ACN-122026638-A

Abstract

The present disclosure provides a wireless power transmitter for detecting a foreign object placed in a charging area of the wireless power transmitter, the wireless power transmitter including a transmitting unit configured to transmit a power signal having a predetermined intensity, and a controller configured to measure a peak frequency of the power signal, receive a foreign object detection status data packet including a mode bit field from a wireless power receiver, the mode bit field indicating whether the foreign object detection status data packet includes a reference peak frequency of the wireless power receiver, wherein the reference peak frequency is pre-allocated to the wireless power receiver, determine an adaptive threshold frequency based on the reference peak frequency in response to the mode bit field indicating that the foreign object detection status data packet includes the reference peak frequency, and determine whether the foreign object is present in the charging area based on the measured peak frequency of the power signal and the determined threshold frequency.

Inventors

Pu Zaixi
Quan Rongyi

Assignees

LG伊诺特有限公司

Dates

Publication Date: 20260512
Application Date: 20170630
Priority Date: 20160701

Claims (10)

1. A wireless power transmitter for detecting a foreign object placed in a charging area of the wireless power transmitter, the wireless power transmitter comprising: a transmitting unit configured to transmit a power signal having a predetermined intensity, and A controller configured to: the peak frequency of the power signal is measured, Receiving a foreign object detection status data packet including a mode bit field indicating whether the foreign object detection status data packet includes a reference peak frequency of the wireless power receiver, wherein the reference peak frequency is pre-allocated to the wireless power receiver, Responsive to the mode bit field indicating that the foreign object detection status data packet includes the reference peak frequency, determining an adaptive threshold frequency based on the reference peak frequency, and Based on the measured peak frequency of the power signal and the determined threshold frequency, it is determined whether a foreign object is present in the charging region.
2. The wireless power transmitter of claim 1, wherein the controller is further configured to: When the peak frequency of the measured power signal is greater than the threshold frequency, a response indicating the presence of foreign matter in the charging region is sent, or When the peak frequency of the measured power signal is equal to or less than the threshold frequency, a response indicating that no foreign matter is present in the charging region is transmitted.
3. The wireless power transmitter of claim 2, wherein the controller is further configured to: If the controller determines that a foreign object is present in the charging region, the power signal is suspended.
4. The wireless power transmitter of claim 1, wherein when a foreign object is present in the charging area, a peak frequency of the measured power signal is shifted.
5. The wireless power transmitter of claim 1, wherein when the mode bit field indicates that the foreign object detection status data packet includes the reference peak frequency, the foreign object detection status data packet further includes a reference peak frequency value of the wireless power receiver.
6. The wireless power transmitter of claim 5, wherein the reference peak frequency is measured with the wireless power receiver off.
7. The wireless power transmitter of claim 1, wherein the adaptive threshold frequency is determined based on a preset tolerance in addition to the reference peak frequency.
8. The wireless power transmitter of claim 1, wherein the reference peak frequency is a pre-measured reference peak frequency in the absence of foreign matter.
9. The wireless power transmitter of claim 1, wherein the adaptive threshold frequency is determined based on a design factor and a predefined tolerance corresponding to the wireless power transmitter.
10. The wireless power transmitter of claim 1, wherein the reference peak frequency is pre-allocated to the wireless power receiver based on a reference wireless power transmitter, and Wherein the adaptive threshold frequency is determined in consideration of at least one of a coil design and a circuit characteristic different from the reference wireless power transmitter.

Description

Wireless power transmitter The present application is a divisional application of chinese patent application No. 202211008315.1 entitled "method of detecting foreign matter in charging area and wireless power transmitter" filed on 22 th 8 th 2022, the above-mentioned patent application No. 202211008315.1 being a divisional application of chinese patent application No. 2017, 6 th 30 th, entitled "method for detecting foreign matter and apparatus and system thereof", international application No. PCT/KR 2017/006975, application No. 201780053470.6 after entering the chinese national stage. Technical Field Embodiments relate to wireless power transfer technology, and more particularly, to a method of detecting foreign objects in a wireless charging system, and an apparatus and system thereof. Background Recently, with the rapid development of information and communication technologies, a ubiquitous society based on information and communication technologies is developing. In order to connect information communication apparatuses anywhere and anytime, sensors equipped with computer chips having communication functions should be installed in all social facilities. Therefore, supplying power to such devices or sensors is a new challenge. In addition, as the types of mobile devices (e.g., music players such as bluetooth handsets or ipods and mobile phones) rapidly increase, users need more time and effort to charge the battery. As a method of solving such a problem, wireless power transfer technology has recently attracted attention. Wireless power transmission or wireless energy transfer refers to a technique of wirelessly transmitting electrical energy from a transmitter to a receiver using magnetic induction principles. In the 19 th century, electrodes or transformers using the principle of electromagnetic induction have been used, and after that, attempts have been made to radiate electromagnetic waves (e.g., high frequency, microwave, and laser) to transmit electric power. The electromagnetic induction principle is used to charge a frequently used electric toothbrush or some wireless shavers. Up to now, wireless energy transfer methods can be broadly classified into a magnetic induction method, an electromagnetic resonance method, and a Radio Frequency (RF) transmission method of short wave radio frequency. The magnetic induction method uses a phenomenon that when two coils are adjacent to each other and then a current is applied to one coil, magnetic flux is generated so that electromotive force is generated in the other coil, and is rapidly commercialized in a small-sized device (e.g., mobile phone). Magnetic induction methods can deliver up to hundreds of kilowatts (kW) of power and have high efficiency. However, since the maximum transmission distance is 1 centimeter (cm) or less, the device to be charged should be adjacent to the charger or the floor. The electromagnetic resonance method uses an electric field or a magnetic field instead of using electromagnetic waves or electric current. The electromagnetic resonance method is rarely affected by electromagnetic waves, and thus is advantageously safe for other electronic devices or human bodies. In contrast, this method can be used in limited distances and spaces and the energy transmission efficiency is somewhat low. The short wave wireless power transmission method (abbreviated as RF transmission method) uses the fact that energy can be directly transmitted and received in the form of radio waves. The technology is an RF wireless power transmission method using a rectenna. Rectenna is a combination of an antenna and a rectifier and refers to an element that converts RF power directly into DC power. That is, the RF method is a technique for converting AC radio waves into DC. Recently, as the efficiency of the RF method increases, commercialization of the RF method has been actively studied. Wireless power transmission technology may be used not only in mobile related industries but also in various industries such as IT, railway, home appliances, and the like. If a conductor (i.e., foreign matter (FO)) other than the wireless power receiver is present in the wireless charging area, an electromagnetic signal received from the wireless power transmitter may be introduced in the FO, thereby increasing the temperature. For example, FO may include coins, clips, pins, and ballpoint pens. If FO is present between the wireless power receiver and the wireless power transmitter, wireless charging efficiency may be significantly reduced, and the temperatures of the wireless power receiver and the wireless power transmitter may increase due to an increase in the ambient temperature of FO. If FO located in the charging area is not removed, power waste may occur, and the wireless power transmitter and the wireless power receiver may be damaged due to overheating. Thus, accurate detection of FO located in a charging area is becoming an important issue in wireless chargi