Constant-current constant-voltage induction type wireless charging system of three-coil structure

Abstract

The invention discloses a constant-current constant-voltage induction type wireless charging system of a three-coil structure. The system comprises a transmitting circuit, a receiving circuit and a constant-current constant-voltage switching circuit. The transmitting circuit comprises a DC power supply, a high-frequency inverter, a primary compensation capacitor and a primary coil connected successively; the receiving circuit comprises a secondary coil, a secondary compensation capacitor, a rectification filtering circuit and a battery load connected successively; the constant-current constant-voltage switching circuit comprises a third coil, a third coil compensation capacitor and a change over switching connected successively, and the control end of the change over switch is connected with a controller; and every two of primary, secondary and third coils for a mutual coil. Both constant current and constant voltage can be output, the system works in one frequency point, frequency bifurcation does not occur, the system works stably, control is convenient, the structure is simple and reliable and the manufacturing cost is low.

Description

technical field [0001] Embodiments of the present invention relate to the technical field of wireless charging, in particular to a constant current and constant voltage inductive wireless charging system with a three-coil structure. Background technique [0002] Inductive wireless power transfer technology is a new type of power supply technology that uses soft media such as magnetic fields to realize non-contact power transmission. It is widely used in medical, consumer electronics, water Power supply, electric vehicle charging and rail transit and other fields. Among them, the use of inductive wireless power transmission technology to wirelessly charge the battery avoids the disadvantages of contact sparks and plug aging in the traditional plug-in system, and has a great development prospect. [0003] In order to achieve safe charging of the battery, prolong the service life of the battery and the number of charge and discharge times, it usually mainly includes two chargi...

AI Technical Summary

Problems solved by technology

[0005] 1. Introduce closed-loop negative feedback control in the circuit system, such as adding a controller before the inverter to adjust the input voltage or adopting phase-shift control, or adding a DC-DC converter after the secondary coil is rectified; the defect is that it increases Control cost and complexity, reduce system stability

[0006] 2. Using frequency conversion control, the system works at two different frequency points to achieve constant current and constant voltage output, but this method will cause frequency bifurcation, resulting in unstable system operation

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