Research Of Multi-load Wireless Power Transmission System Based On LCC Compensation Network

As a new type of power transmission technology,Wireless Power Transfer(WPT)technology has caused extensive research in the industry and academia in recent years.In many ways of powering multiple loads,wireless power transmission technology has many unique advantages.In many practical engineering applications,it is often required to supply constant voltage to the loads,and the change in the number of receivers and the instability of the load may affect the constant voltage output characteristics of the system.In view of the above-mentioned constant voltage output requirements for multiload wireless power transmission systems,this paper studies the scheme of system load constant voltage output under the condition of the number of receivers and the unstable load from the perspective of system compensation network.Firstly,a brief comparison is made between the three commonly used multi-load WPT system structures.In this paper,the system structure of the transmitting coils is used to supply power to multiple loads at the secondary side.Based on the circuit principle and mutual inductance coupling model,two high-order circuit topologies are constructed.The frequency characteristics and output characteristics of the two topologies are analyzed in detail.Combined with the frequency characteristics of the above two high-order circuit topologies,compensation networks that meet the output specifications of the multi-load WPT system is designed: LCC-S compensation network,LCC-LCL compensation network.Based on the mutual inductance coupling model,study the influence of the number of receivers and load changes on its constant voltage output characteristics and transmission efficiency characteristics.According to the derived voltage output and transmission efficiency expression,the coil self-inductance and coupling coefficient is used as two variables to study its influence on power transmission efficiency,and then the variable range of the system with higher transmission efficiency is obtained.Secondly,for the cross-coupling between the primary and secondary transmit and receive coils of the LCC-S compensation network,this paper establishes the system circuit model according to the circuit principle and mutual inductance coupling model,and applies the impedance compensation principle to derive the cross-coupling of the multi-load WPT system.Impedance compensation expression,for the actual application,give the corresponding impedance compensation ideas.Finally,Maxwell simulation software is used to complete the design of coil wire diameter,number of turns and winding method in the coupling mechanism.This paper builds a 34 V DC source power supply,three-load constant voltage 12 V output WPT system model,based on the above theoretical research results.The experimental results show that the three-load WPT system based on two compensation networks can simultaneously output 12 V voltage at a constant voltage simultaneously mounting 3?,6? and 10? loads and having different receiving ends.When the system cross-coupling,the output voltage of the system drops by about 8% of the rated output voltage.Through the impedance compensation strategy proposed in this paper,the system output voltage drop can be increased by about 4%.