Constant current and constant voltage inductive wireless charging system based on variable primary parameters

Abstract

The invention discloses a constant current and constant voltage inductive wireless charging system based on variable primary parameters. It is composed of a sending part and a receiving part. The constant current and constant voltage switching circuit provided in the sending part is realized. The composition of the switching circuit is: A primary constant current capacitor (CPC) and a primary additional series capacitor (CPS) are connected in series between the high-frequency inverter (H) and the primary coil, and switch one is connected in parallel with the primary additional series capacitor (CPS); and the switch The control terminal of one is connected with the controller one, as shown in Figure 1; or the sending part is provided with a constant current and constant voltage switching circuit two, and the composition of the switching circuit two is: between the high frequency inverter (H) and the primary coil The primary constant voltage capacitor (CPV) is connected in series; the primary additional parallel capacitor (CPP) is connected in series with the switching switch 2 and then connected in parallel to the primary constant voltage capacitor (CPV), and the control terminal of the switching switch 2 is connected to the controller 2. The system can output constant current and constant voltage irrelevant to load, has simple structure and control, stable operation and low manufacturing cost.

Description

technical field [0001] The invention relates to a constant current and constant voltage inductive wireless charging system based on variable primary parameters. 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 c...

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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