Study On Protection Technology In ICPT System For Safe Operation

Inductively coupled power transfer (ICPT) technology is the integrated use ofmodern power electronic technology, magnetic field coupling technology and moderncontrol theory. ICPT technology that get rid of the direct contact power supply modeand achieve non-contact power supply depend on electromagnetic couplingrelationship is a new power transmission technology， which remove the shortcomingsof exposure to electric spark and mechanism wear. It has the advantages of safety，environmental protection, low maintenance, and adaptability. Therefore, inductivelycoupled power transfer (ICPT) technology has earned the wide attention among thescholars at home and abroad which has obtained the rapid development.ICPT system applied large of power semiconductor devices to convert and controlelectric energy. It is easy for these semiconductor devices to be out of trouble becauseof poor working conditions, such as high voltage, large current. So ICPT system cannot realize grand-scale commercial because of safety operation problem. In order toguarantee the security and stability of ICPT system, it is necessary to analyze fully thefactor of influencing safe operation of system and take relative measures to eliminateand regulate. And analysis showed that instantaneous peak voltage and current, such aspower-on current surge, voltage and current peak which happen when the power switchtube open and off, is the main reason during the operation of ICPT system. In order tosolve these problems, the paper found the cause of these problems based on workingprinciple of ICPT system, which provide a theoretical basis for the prevention andelimination of these factors.The method that access fixed resistance during the start-up restrain effectivelyundermine of power-on current surge. Aimed at the voltage peak of DC voltageregulating circuit, the paper designed one Lossless buffer circuit which improveeffectively switch and the freewheeling diode working environment, meanwhile,deduced parameter design formula. Aimed at the voltage peak of resonant invertercircuit, the paper designed one large power system discharge stop buffer circuit whichimprove bridge arm switch tube working environment, in the meanwhile, the relatedparameters design formula for the system were derived. In order to ensure full securitysystem safety operation, the paper designed relative protection circuit based on theproblem of conventional safety hidden danger, such as overheating, over-voltage, over current.Finally, the corresponding hardware circuit was designed and produced, andfinished the experimental verification of hardware circuit. Results show that thedesigned protection circuit is helpful to improve the work environment and guaranteethe security and stability of system operation.