The Research On Single-wire And Spatial Electric Field Based Power Transmission

Single-wire and spatial electric field based power transmission,which is called Single-wire power transmission(SWPT)for short,is a kind of technology in which only a single wire is used.Although the SPWT technology has been proposed for more than a hundred years,few people engage in this field due to the principle,technic and other reasons.Compared with magnetically-coupled resonant wireless power transmission,energy can be transmitted to farther distance in higher efficiency by using SWPT technology.Power supply can be more flexible when the power transmission is achieved by replacing the single wire with the steel structure of the buildings,or the ocean and other natural conductive mediums.The research status and development trends of SWPT technology are expounded.The circuit model and the calculation of the element parameters in the model are introduced.Based on the features of the element parameters,the circuit model is simplified.In addition,the SWPT system is analyzed from the perspective of electromagnetic field by taking the ideal dipole model as an example.To study the SWPT technology,four different structures of the SWPT systems with are designed and produced.Simulink is used to simulate the circuit model of the torus-cylinder type SWPT system.The relationship between the frequency and the input impedance,input current,voltage gain and transmission efficiency are obtained.The relationship between the load resistance and the efficiency,the transmission distance and the efficiency are also analyzed by the simulation.The simulation results are compared with the experiment results.And a method to determine the optimal operating frequency of the SWPT system is proposed.A high frequency inverter power supply used for laboratory experiment and a portable high frequency power supply used for outdoor experiment are designed.By using the former power supply and the metal wire as the single-wire,935 W electric power can be received in 5 meters long and the efficiency is 60.8%.By using the later power supply,100 W electric power can be received in 60 meters long and the efficiency is 35%.Several watts can be transmitted when the single wire is replaced by the caliduct,the sea and the damp soil.