| Compared with traditional wired power transmission technology,wireless power transmission technology has the advantages of better security and convenience,and can be flexibly applied to many special applications.In recent years,it has obtained extensive research and application development.In the wireless power transmission system,when there is a communication module or a control module on the receiving side,the volume and weight of the circuit on the secondary side is an unavoidable problem,and it is difficult to apply to applications that have restrictions on the volume and weight of the receiving side.In this context,this article proposes a wireless power transmission system with no communication between the primary and secondary sides and only controlled by the transmitting side.This article starts with the structure and principle of the inductive wireless power transmission system,and establishes the transformer model of the magnetic coupling mechanism in the system through circuit theory.Based on the transformer mutual inductance model,the compensation circuit is analyzed.Through the analysis of several topologies available in the WPT system,it is determined that the compensation network combined with the transmitting-side LCC network and the receiving-side S network can take into account both the transmitting-side control and the guarantee system.Two characteristics of the receiving side voltage regulation.Analyze the harmonic characteristics and output characteristics of the three alternative topologies studied in the Psim software,and confirm that the selected LCC-S network has certain advantages in terms of anti-high harmonic characteristics and constant voltage output characteristics.It is suitable for the constant voltage output system studied in this article.On the basis of determining the circuit structure of the compensation network,the circuit composition of the wireless power transmission system and the equivalent model of the primary and secondary circuit are determined.The mutual inductance of the inherent parameters of the system is analyzed first,and the mutual inductance is designed based on the theoretical basis of the input impedance changing with frequency.Solving method,and then determine the estimation method of the output side voltage and current by analyzing the circuit equation.The sensitivity analysis of the proposed parameter estimation method is carried out,and the effective frequency range of the calculation method is determined.The output side voltage and current estimation algorithm is compiled in the simulation software and its validity and accuracy are verified.According to the design of the control strategy of the WPT system,the small signal modeling of the circuit as a whole is carried out through the state space method.The small signal model is used to design the controller parameters of the voltage and current on the load side of the system and the phase-shift controller used to optimize the power factor angle of the inverter circuit.The designed control strategy is based on the background of single-side control,taking into account the optimization of output-side regulated output and system efficiency,and the phase angle between the output voltage and current of the transmitting-side inverter circuit is controlled at about 3°.A wireless wireless power transmission system with an input of 45-55 V and a regulated output of 30 V on the secondary side was built under the co-simulation environment between the three softwares of Simplorer-Maxwell-Simulink,and the proposed parameter estimation method and control strategy were implemented to verify The designed WPT system achieves constant voltage output while achieving the ZPA output of the primary inverter circuit under the condition of no communication and no controller on the secondary side.The estimation method and the control method proposed in the article are verified. |
