Constant-current constant-voltage inductive wireless charging system

Abstract

The invention discloses a constant-current constant-voltage inductive wireless charging system. The constant-current constant-voltage inductive wireless charging system consists of a transmission part and a receiving part, wherein the receiving part is provided with a constant-current constant-voltage switching circuit I (Q<1>); the switching circuit I is constructed in a way that a secondary constant-voltage capacitor (C<SV>) and a secondary additional series capacitor (C<SS>) are connected in series, and then connected in parallel to two ends of a secondary coil (L<S>); a shift switch I (S<1>) is connected in parallel with the secondary additional series capacitance (C<SS>); a control end of the shift switch I (S<1>) is connected with a controller I (K<1>); or the receiving part is provided with a constant-current constant-voltage shift switch II (Q<2>); the shift circuit II (Q<2>) is constructed in a way that a secondary constant-current capacitor (C<SC>) is connected in parallel to two ends of the secondary coil (L<S>); a secondary additional parallel capacitor (C<SP>) and the shift switch II (S<2>) are connected in series, and then connected in parallel to the secondary constant-current capacitor (C<SC>); and a control end of the shift switch II (S<2>) is connected with a controller II (K<2>). Through adoption of the constant-current constant-voltage inductive wireless charging system, constant current and constant voltage being irrelevant to loads can be output. Moreover, the constant-current constant-voltage inductive wireless charging system has the advantages of simple structure, easiness in control, stable work and low manufacturing cost.

Description

technical field [0001] The invention relates to a constant current and constant voltage inductive wireless charging system. Background technique [0002] Inductive wireless power transmission technology provides flexible, safe and reliable power supply to electrical appliances in a non-contact manner through a magnetic field, avoiding safety problems such as contact sparks and leakage in traditional plug-in power transmission systems. The technology is already widely used in built-in medical devices, consumer electronics, lighting and electric vehicles. Among them, the use of inductive wireless power transfer systems for wireless charging of batteries has great development prospects. [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 charging stages of constant current and constant voltage. That is, the constant current mode is used at the initial st...

AI Technical Summary

Problems solved by technology

Since the equivalent impedance of the load (battery) changes, it is difficult for the system to output the constant current or voltage required by the load under a certain input voltage.

In order to solve this problem, there are usually two methods: 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 negative feedback control after the secondary coil rectification DC-DC converter; its disadvantage is that it increases the cost and complexity of control and reduces the stability of the system

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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