Energy Control And Design Technology Of Inductive Power Transmission

With the development of industrial automation, automation equipment in motion puts forward new requirement in the continuous power supply. Inductive power transmission(IPT) increases the flexibility of the equipment by physical separation, and also makes up the disadvantage, such as wear, carbon deposition or electric spark in traditional sliding power devices. IPT can be used widely in consumer electronics, logistics automation, motor vehicle and other fields, which leads to a great theoretical significance and engineering value to research IPT system.For the application of IPT in the conveying system in automobile assembly, some key parts of IPT, such as inductive couple, compensation and high frequency inverter, are investigated based on existing theories in this dissertation. In order to decrease the enegy loss coursed by resonant current in IPT couple structure and elements, the couple structure and compensation circuit are optimized and designed, and then, the control algorithm of the inventer is designed to adjust resonant current. Accordingly, it is implemented to save comprehensive energy of IPT system.At the level of theoretical research, the design of magnetic structure is decoupled based on a new definition of mutual inductance coefficient. The principle and method are presented to optimize transmission power and efficiency under considering a variety of parameters in electric, magnetic and structure. By piecewise linearization of high order and nonlinear system, a general stroboscopic mapping model is created based on state-space method. Then, the equations for calculating the periods and the steady-state waveforms are inferred. The method is proposed to find working point of soft switching mode, and its existence and quantity are anazied in common IPT system.At the level of technology development, firstly, the design flow is shown, which is beneficial to the size reduction of magnetic core and the increasement of transmission power and efficiency. Secondly, the circuit of IPT system based on double inductance-capacitance-inductance(LCL) compensation is given, and the parameter of each component is inferred. Thirdly, the system working mode is presented using pulse density modulation(PDM). The feasibility and control parameters are discussed. Similarly, pulse density and frequency modulation(PDM/PFM) and enhance PDM are presented and studied. Finally, the IPT model with energy control and conversion technology is given.For experiment, two IPT prototypes are developed. The first one is double-LCL IPT system which works under fixed frequency. The performance of constant current and voltage is tested. It is verified in the prototype that transmission power and efficiency of the secondary part have nothing to do with the number of the secondary winding. The next one is developped with energy control and conversion technology based on enhance PDM mode. The modeling and solving of soft switching working point is proved by testing, and the feasibility of energy control algorithms for high order and nonlinear system is proved.The feasibility of the theories proposed is verified by numerical simulation, and then theoretical results are converted into the circuits of IPT protypes. Many system operation tests are carried out. The results of experiments have sufficiently verified the effectiveness and superiority of the system design and energy control techniques proposed in this dissertation.