A High Efficiency Resonant Wireless Power Transmission System

Abstract

The present invention proposes a high-efficiency resonant wireless power transmission system, including (1) coupling coil L Tx and L Rx and resonant capacitor C Tx and C Rx Constitute a series resonant network; (2) The input voltage V of the transmitting side dc , input choke inductance L in , the main switch tube M Tx and its parallel capacitor C ds1 Constitute a class E inverter circuit; (3) output capacitor C on the receiving side o , output choke inductance L out , synchronous switching tube M Rx and its parallel capacitor C ds2 A Class E synchronous rectification circuit is formed. The present invention adopts the E-type synchronous rectification circuit to replace the conventional diode rectification, which can greatly reduce the conduction loss of the lossy diode and improve the system efficiency; Rx The turn-on and turn-off information is obtained at the conduction voltage drop, which avoids the problems of traditional synchronous rectification technology; the high-efficiency auxiliary source circuit based on transformer energy harvesting can greatly reduce the low efficiency of traditional linear auxiliary sources and improve the overall efficiency of the system.

Description

technical field [0001] The invention relates to a power transmission system, in particular to a high-efficiency resonant wireless power transmission system. Background technique [0002] The core architecture of the magnetic coupling resonant wireless energy transfer system is as follows: figure 1 As shown, through two inductance coils L Tx and L Rx The coupling realizes the transmission of electric energy. Due to the existence of coil leakage inductance, the transmitted power and efficiency are very low in the direct coupling state. Therefore, the inductance coil and the capacitor are connected in series to form a resonance to form a resonant wireless energy transmission system to improve efficiency and power. figure 1 in, U in is the input AC source, L Tx and L Rx is the coupled inductance coil, C Tx and C Rx is the resonant capacitor, R Tx and R Rx is the internal resistance of the resonant tank, R L is the equivalent AC load resistance. However, the core arch...

AI Technical Summary

Problems solved by technology

However, the Class D resonant power amplifier circuit has some inevitable defects: (1) The bridge circuit requires a dead zone circuit, so the maximum operating frequency is limited; (2) The bridge circuit drive will have a latch-up effect, which affects system reliability; (3) The discontinuous input current requires an additional input filter circuit; (4) The longer diode reverse conduction time reduces the system efficiency

[0007] However, there are still many problems to be solved in the "DC-DC" wireless energy transmission system under the E-class topology, including: (1) the loss of the diode on the rectification side is large, which affects the system efficiency; (2) the traditional synchronous rectification technology needs The terminal transmits the signal to the receiving end, but it is different from the general isolated power supply in the wireless charging application. Due to the distance limitation, it is impossible to add an additional transformer or optocoupler to transmit the synchronous rectification information; (3) in the application of higher voltage (>24V) In this case, if the auxiliary power supply of the transmitting end and the receiving end is powered by a linear circuit, additional power consumption will be generated and the system efficiency will be reduced.

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