Illegal load detection method based on wireless power transmission channel

Abstract

The invention discloses an illegal load detection method based on a wireless power transmission channel. The device comprises a high-frequency electromagnetic coupling mechanism and a load, wherein the high-frequency electromagnetic coupling mechanism comprises a primary side coil and a secondary side coil. The detection method comprises the following steps: (1) modulating a square signal with thefrequency of f1 on the load; (2) controlling the load to be switched on and switched off at the frequency of f1; (3) detecting the square frequency of input current of the primary side coil to be marked as f2; and (4) if the absolute value of f2-f1 is smaller than or equal to a given preset value epsilon, regarding the load as a legal load, otherwise, regarding the load as an illegal load. A loadidentification signal is directly transferred on the energy transmission channel, so that the interference of a magnetic field during transferring is avoided, and the rate of identification is improved. The method is simple, quick and accurate, and meets the realistic condition that the standing time of an electric vehicle on a single guide rail coil in wireless power supply application is extremely low.

Description

technical field [0001] The invention belongs to the technical field of electric vehicle wireless charging, and in particular relates to an illegal load detection method based on a wireless energy transmission channel. Background technique [0002] The non-contact power transmission (CPT) technology based on the principle of electromagnetic induction coupling increases the flexibility of electrical equipment and makes up for the defects of device wear, carbon deposition and electric sparks in the traditional contact power transmission method, so it is a safe , Reliable and flexible power access new technology. However, since CPT technology is still in its infancy, the energy efficiency (transmission power and efficiency) of the system is still low, which affects its promotion and application. [0003] In the electric vehicle wireless charging system, there is a large air gap between the primary side and the secondary side of the system, and it is an open-air environment. The...

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Problems solved by technology

During the charging process, there is a strong alternating magnetic field between the air gaps. When organisms stray into the transmission space, it will affect their health; when the medium is an insulator or a poor conductor with high resistivity, the induced electromotive force will not Large eddy currents are generated, resulting in small power loss; but if the medium is a metal conductor, due to its low resistivity, the same electromotive force will generate large eddy currents, resulting in large power losses, which not only reduces efficiency, Moreover, the eddy current heating of the metal will also bring huge potential safety hazards to the system.

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