Wireless charging system and power transmission control method thereof

Abstract

The embodiment of the invention provides a wireless charging system and a method for controlling power transmission of the wireless charging system. The wireless charging system comprises a wireless charging emission end and a wireless charging receiving end. The method comprises the steps of detecting a coupling coefficient between the wireless charging emission end and the wireless charging receiving end; calculating a wireless charging power of the wireless charging system according to the coupling coefficient between the wireless charging emission end and the wireless charging receiving end; and adjusting a compensation parameter of a compensation network of the wireless charging emission end and / or the wireless charging receiving end on the condition that the wireless charging power is lower than a preset power, so that the wireless charging power is larger or equal to the preset power. According to the wireless charging system and the method, stable power transmission can be achieved by adjusting the parameter of the compensation network.

Description

technical field [0001] The present invention relates to the technical field of wireless charging, in particular to a wireless charging system and a method for controlling power transmission of the wireless charging system. Background technique [0002] Electric vehicles (EV) have the advantages of environmental protection and zero emission, so they have been developed rapidly. At present, electric vehicles are mainly charged by wires. This charging method has disadvantages such as easy sparks and wear when plugged in, not safe enough, and difficult to maintain. Wireless power transmission technology gets rid of the dependence on wires, can effectively overcome the above shortcomings, and makes electric vehicles have a new choice for power supply. [0003] A typical wireless charging system such as figure 1 As shown, firstly, the single-phase or three-phase power supply 11 is rectified and filtered by the AC / DC 12 and then converted into direct current, then converted into ...

AI Technical Summary

Problems solved by technology

Among them, the charging current of constant current charging is relatively small in the initial stage, and the charging current is relatively large in the later stage, the whole charging time is too long and the energy consumption is large.

In the initial stage of constant voltage charging, the electromotive force of the battery is small, so the charging current is very large, which affects the battery life.

[0005] In the research of wireless charging of electric vehicles, a typical compensation network is a bilateral LCC compensation network, such as figure 2 As shown, the characteristic of the compensation network is that the charging current has nothing to do with the load, and constant current charging can be realized. However, the charging current of this charging method is relatively small in the initial stage, and the charging current is relatively large in the later stage, and the entire charging time is too long. High energy consumption, easy to cause damage to the battery in the later stage of charging

Another typical compensation network is the LCC-C compensation network. The induced voltage on the secondary side has the characteristics of a constant voltage source, but the induced voltage on the secondary side is affected by multiple parameters such as coupling coefficient, compensation network, and power supply voltage, and the voltage value is different. Stable, if its voltage value exceeds the battery voltage too much, it is easy to cause damage to the battery

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