| Wireless Power Transfer(WPT)technology realizes non-contact electric energy transmission in the form of energy conversion,improves the flexibility of electrical equipment and the security of Power system,and has been applied in many fields in recent years.However,WPT system has a high requirement for the relative position of the transmission coil,so the receiving end cannot be guaranteed to be in the optimal position in practical application,so it is difficult to achieve the optimal charging performance,and at the same time,it will affect the normal operation of electrical equipment.In this paper,an efficiency optimization method based on parameter adjustment is proposed to study the efficiency loss caused by the non-coaxial position of the coil in the traditional power transmission system.First based on the system transmission coil position deviation as the research object,with the aim to optimize the system transmission performance as the research target,based on WPT transmission performance of the system under SS topology analysis found that the coil position will offset the transmission performance of the system as the operating frequency and the load resistance change,combined with the actual needs to choose the work frequency of the system and the load resistance;The selection of coil parameters in the WPT system has the greatest influence on the transmission performance of the system.The shape and size of the coil are simulated and analyzed by using the Maxwell finite element simulation software,and the coil parameters suitable for this paper are selected.By comparing the transmission performance of the system under different topologies,the twosided LCC was selected as the topology structure in this paper.In addition,to solve the problem of system transmission efficiency reduction caused by coil offset,a parameter design method based on firefly algorithm is proposed in this paper to realize the efficiency optimization when the coil is placed in non-coaxial position.Combined with the transmission performance of the two-sided LCC topology,the influence of different compensation inductors on the output power and transmission efficiency of the system under coil offset is analyzed.Introduction of firefly algorithm,the optimal location of SS topology under transmission efficiency as the object of comparison,with bilateral LCC topology structure under the maximum transmission efficiency as objective function,to maintain the resonance and power as constraint conditions on the compensated inductance load optimization,to achieve the transfer efficiency of the system and when the position offset load power optimization,the optimization results show that while maintaining the load power,transmit and receive coil offset is less than the radius of coil,transmission efficiency up to70%,the highest transfer efficiency can reach 83%.Finally,the coil simulation model and the experimental platform of the system are designed.The simulation results show that the optimized topology has stronger magnetic field strength when the position deviation occurs,and the resonance of the detuned coil can be established again.The experimental results show that compared with the traditional SS topology,the transmission efficiency of the optimized system is improved by 20% on average under the condition of coil offset. |
