Inductive wireless power transfer system capable of outputting both constant current and constant voltage

Abstract

The invention discloses an inductive wireless power transmission system capable of outputting both constant current and constant voltage. It is composed of a sending part and a receiving part. The constant current and constant voltage switching circuit (I) of the sending part is composed of: high frequency The primary constant voltage capacitor (CPv) is connected in series between the inverter (H) and the primary coil (LP); after the additional parallel capacitor (CPp) is connected in series with the switch one (S1), it is connected with the primary constant voltage capacitor (CPv) parallel connection; and the control terminal of switch one (S1) is connected with controller one (K1); or the primary constant current capacitor (CPi) and An additional series capacitor (CPs); the switch two (S2) is connected in parallel to the additional series capacitor (CPs); and the control terminal of the switch two (S2) is connected to the controller two (K2). The system can output both constant current and constant voltage, and the control is convenient, the system works stably, the structure is simple, and the manufacturing cost is low.

Description

technical field [0001] The invention relates to an inductive wireless power transmission system capable of outputting both constant current and constant voltage. 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 ...

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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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