An anti-skew wireless power transfer system based on combined topology

Abstract

The invention discloses an anti-offset wireless power transmission system based on a combined topology. The voltage provided to a load is approximately constant under a large offset and has small fluctuations, and is suitable for wireless power transmission occasions. The system includes a high-frequency full-bridge inverter circuit, a primary-side compensation network, a loosely coupled transformer, a secondary-side compensation network, and a full-bridge rectification and filtering circuit. The combined topology utilizes the output characteristics of the S / LCC and LCC / S compensation topologies, and through the connection of the primary side in series and the secondary side in parallel, it realizes the load compensation in the case of a large coil offset. Provide approximately constant voltage, and at the same time, can achieve approximately zero power factor of input impedance and soft switching of switching devices, which solves the problem that the output voltage of the existing constant voltage output wireless power transmission system fluctuates greatly with the offset of the loosely coupled transformer coil problem, and the loosely coupled transformers used in the two topologies can be integrated into the design without adding additional volume.

Description

technical field [0001] The invention discloses an anti-deviation wireless power transmission system based on combined topology, which belongs to the wireless power transmission technology. Background technique [0002] Wireless charging technology (Wireless Power Transfer, WPT) is convenient, safe and reliable because there is no electrical and mechanical connection between the power supply end and the power receiving end. At present, the electromagnetic induction wireless power transfer (Inductive Power Transfer, IPT) technology is the most widely used WPT technology, so it has great research value. [0003] The loosely coupled transformer used in IPT technology has low coupling coefficient and large leakage inductance, which inevitably generates reactive circulating current in the circuit, which increases device stress and loss. Therefore, a compensation network is generally used to compensate the reactive energy generated by leakage inductance. Moreover, the compensation...

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Problems solved by technology

[0004] Since IPT uses a loosely coupled transformer to transmit energy, and the transmitting coil and receiving coil can move freely, it is inevitable that the two coils will be offset during the actual charging process, which will cause changes in the parameters of the compensation network, output voltage or current. There are large fluctuations

Aiming at the problem of transformer coil offset, some studies have proposed a new control strategy, but it reduces the transmission efficiency and reliability

Studies have proposed some coil design methods, such as: DD, DDQ and other coil structures, but none of them can effectively improve the offset problem

It has been proposed to use the characteristics of the S / LCC compensation topology and the LCC / S compensation topology to achieve constant voltage output and ZPA through the parallel connection of the primary side and the series connection of the secondary side. It also has good anti-offset capability, and adopts The integrated coil reduces the volume of the transformer, and the transmission efficiency and reliability are not affected. However, when the coil deviation of the loosely coupled transformer increases beyond a certain range, the voltage and current stress of the combined topology increase exponentially, which endangers the stable operation of the system.

[0005] From the above analysis, it can be seen that the current combined topology that can achieve constant voltage output and input ZPA and has good anti-offset capability still has the voltage and current stress of the combined topology that increases exponentially after the transformer coil deviation increases beyond a certain range. The problem

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